阅读说明：本技术 计数器单元、计数器单元的控制方法、控制装置以及控制系统 (Counter unit, control method, control device, and control system for counter unit ) 是由 丹羽祥実 于 2020-02-03 设计创作，主要内容包括：不依存于脉冲信号的周期而调整向致动器的输出的时机。计数器单元(10)在从判定为使用脉冲信号而测量的实测值与目标值一致的时间点经过了从PLC(20)收到的时机调整值(Ta)所示的待机时间的时间点,执行向致动器(40)的输出。(The timing of output to the actuator is adjusted independently of the period of the pulse signal. The counter unit (10) outputs to the actuator (40) when a standby time indicated by the timing adjustment value (Ta) received from the PLC (20) has elapsed from the time when the actual measurement value measured using the pulse signal is determined to match the target value.)

1. A counter unit, comprising:

a measuring unit for counting the number of pulses of the pulse signal to measure an actual measurement value;

a comparison unit configured to determine whether the actual measurement value measured by the measurement unit matches a target value; and

an output unit that outputs to an actuator when the comparison unit determines that the actual measurement value matches the target value,

the output unit includes an output delay unit that adjusts the timing of the output to a point in time that is independent of the period of the pulse signal and is indicated by a timing adjustment value after the point in time at which the comparison unit determines that the actual measurement value matches the target value has elapsed.

2. The counter unit of claim 1, wherein

The output section includes a hardware-based logic circuit,

the time indicated by the timing adjustment value is an integer multiple of the clock of the logic circuit.

3. The counter unit of claim 1 or 2, further comprising:

and a communication unit that receives the target value and the timing adjustment value from a control device that performs an input/output process of on/off data at a predetermined control cycle.

4. Counter unit according to any of claims 1 to 3, wherein

The timing adjustment value is updated using a feedback value indicating an actual state of the workpiece realized by the actuator that receives the output from the counter unit.

5. The counter unit of claim 4, wherein

The timing adjustment value is updated using a difference between a reference value indicating a predetermined ideal state of the workpiece to be realized by the actuator that has received the output and a value calculated by performing statistical processing on the plurality of feedback values.

6. A control apparatus that performs input/output processing of enable/disable data at a prescribed control cycle, comprising:

an updating unit that updates the timing adjustment value using, as a feedback value relating to the output, a value indicating an actual state of the workpiece achieved by the actuator that has received the output from the counter unit,

the timing adjustment value and the target value updated by the updating section are transmitted to the counter unit according to claim 3.

7. The control device of claim 6, wherein

The update unit updates the timing adjustment value using a difference between a reference value indicating a predetermined ideal state of the workpiece to be realized by the actuator that has received the output and a value calculated by performing statistical processing on a plurality of the feedback values.

8. A control system, comprising:

a counter unit as claimed in claim 3;

the control device according to claim 6 or 7; and

and a state detection device that detects an actual state of the workpiece realized by the actuator that receives the output from the counter unit, and transmits a value indicating the detected actual state of the workpiece to the control device as the feedback value.

9. The control system of claim 8, wherein

The control device updates the timing adjustment value using a difference between a reference value indicating a predetermined ideal state of the workpiece to be realized by the actuator that has received the output and a value calculated by performing statistical processing on a plurality of the feedback values.

10. A control method of a counter unit, comprising:

a measuring step of counting the number of pulses of the pulse signal to measure an actual measurement value;

a comparison step of determining whether the measured value measured in the measurement step matches a target value; and

an output step of outputting to an actuator when the actual measurement value is determined to match the target value in the comparison step,

the output step includes an output delay step of adjusting the timing of the output to a point in time that is independent of the period of the pulse signal and is indicated by a timing adjustment value after the point in time at which the comparison step determines that the actual measurement value matches the target value has elapsed.

Technical Field

The present invention relates to a counter unit (counter unit) and the like that outputs an operation instruction to an actuator when it is determined that a position, an accumulation amount, and the like of a workpiece satisfy a predetermined condition.

Background

Conventionally, it is known that in a production site such as a factory, a counter unit is used to adjust timing for causing an actuator to perform a predetermined operation. For example, patent document 1 below discloses a technique of: a counter unit for quantitatively extracting a liquid using a pulse signal from a flow sensor corrects a reference set pulse number corresponding to quantitative extraction in accordance with a change in a cycle length of the pulse signal.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 11-45374 "

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional counter unit as described above, the timing of output to the actuator is adjusted by increasing or decreasing the target value compared with the actual measurement value measured using the number of pulses (i.e., the count value) of the pulse signal, and therefore, there are the following problems. That is, the conventional counter unit that adjusts the output timing by increasing or decreasing the target value has the following problems: the amplitude of the adjustable timing cannot be made smaller than the period of the pulse signal, and thus if the period of the pulse signal is long, the timing error becomes large. Further, the conventional counter unit has the following problems: when the period of the pulse signal changes, if the output timing is to be maintained the same before and after the period change, the target value to be compared with the actual measurement value must be increased or decreased, which is inconvenient for the user. Hereinafter, the details of the conventional counter unit will be described with reference to fig. 12 and 13.

(mounting application related to past example)

Fig. 12 is a diagram showing a process (hereinafter, also referred to as "mounting application") performed by the counter unit 98 or the like, which is a conventional counter unit, in relation to a process (hereinafter, also referred to as "mounting application") in which the actuator 40 mounts (mounts) a component (mounting member 70) to the workpiece 60. In fig. 12 (a), (B), and (C), the workpiece 60 is loaded by the conveyor and moved at a constant speed in the direction from the left to the right of the paper surface.

As shown in fig. 12 a, the counter unit 98 uses the pulse signal from the encoder 30, that is, the count value to grasp the position (actual measurement value) of the workpiece 60. When the counter unit 98 determines that "the workpiece 60 has reached the start position (target value)", output to the actuator 40 that grips the fitting member 70 (comparison matching output) is performed.

As shown in fig. 12 (B), the actuator 40 receiving the output from the counter unit 98 mounts the fitting member 70 to the workpiece 60. As shown in fig. 12 (C), the workpiece 60 to which the mounting member 70 is attached by the actuator 40 is further moved at a constant speed in the direction from the left to the right of the paper surface.

Here, as shown in (D) of fig. 12, a response time is required from the time point when the counter unit 98 determines that "the workpiece 60 has reached the start position" until the time point when the fitting member 70 is attached to the workpiece 60 by the actuator 40. The response time is a time including "time required for the circuit to respond" and "time required for the mechanical response", and is considered to be fixed. That is, it takes time for the circuit to respond until the actuator 40 receives the output from the counter unit 98 at the time point when the position of the workpiece 60 is determined to have matched with the start position. Further, a time required for a mechanical response is required until the actuator 40 receives the output from the counter unit 98 and executes a process corresponding to the output from the counter unit 98 from the actuator 40. That is, the time required for the mechanical response is required from the counter unit 98 executing the output to the actuator 40 until the fitting member 70 is mounted to the workpiece 60 by the actuator 40.

In fig. 12 (D), the "mounting position" refers to the position of the workpiece 60 at the time point when the response time has elapsed from the time point when it is determined that the workpiece 60 has reached the start position, and refers to the position of the workpiece 60 at the time point when the mounting member 70 is mounted.

Here, if the actual position of the workpiece 60 at the time point when the attachment member 70 is attached is located on the right side of the paper surface than the ideal position of the workpiece 60 at the time point when the attachment member 70 is attached, the counter unit 98 executes the following processing. That is, when the workpiece 60 reaches a position shifted to the left side of the original start position on the paper surface, the counter unit 98 outputs the output to the actuator 40, and causes the actuator 40 to perform the mounting of the mounting member 70 to the workpiece 60. By executing the output when the original start position of the workpiece 60 is shifted to the left side of the paper surface, the counter unit 98 can shift the position of the workpiece 60 at the time point when the attachment member 70 is attached to the left side of the paper surface from the original attachment position.

When a position set back from the original start position by a distance of "1 cycle of the pulse signal (i.e., 1 pulse cycle)" is set as the "correction start position (front)", the counter unit 98 can realize the following state by using the correction start position (front). That is, by executing the output when the workpiece 60 reaches the correction start position (front), the counter unit 98 can change the position of the workpiece 60 at the time point when the mounting member 70 is mounted to the correction mounting position (front). The "correction assembly position (front)" is the position of the workpiece 60 at the time point when the response time has elapsed from the time point when the counter unit 98 determines that the workpiece 60 has reached the correction start position (front) ". When the cycle (pulse cycle) of the pulse signal is fixed, "the corrected mounting position (front)" is a position that is retracted from the original mounting position by a distance corresponding to "1 pulse cycle".

Similarly, if the actual position of the workpiece 60 at the time point when the fitting member 70 is attached is located on the left side of the plane of the drawing than the ideal position of the workpiece 60 at the time point when the fitting member 70 is attached, the counter unit 98 executes the following processing. That is, when the workpiece 60 reaches a position shifted from the original start position to the right side of the paper surface, the counter unit 98 outputs the output to the actuator 40, and causes the actuator 40 to perform the mounting of the mounting member 70 to the workpiece 60. By executing the output when the workpiece 60 reaches the position shifted to the right of the paper surface from the original start position, the counter unit 98 can shift the position of the workpiece 60 at the time point when the attachment member 70 is attached to the right of the paper surface from the original attachment position.

If the position advanced from the original start position by the distance corresponding to "1 cycle of the pulse signal (i.e., 1 pulse cycle)" is set as the "correction start position (rear)", the counter unit 98 can realize the following state by using the correction start position (rear). That is, by executing the output when the workpiece 60 reaches the correction start position (rear), the counter unit 98 can change the position of the workpiece 60 at the time point when the mounting member 70 is mounted to the correction mounting position (rear). The "correction assembly position (rear)" is the position of the workpiece 60 at the time point when the response time has elapsed from the time point when the counter unit 98 determines that the workpiece 60 has reached the correction start position (rear) ". When the period (pulse period) of the pulse signal is fixed, "the corrected mounting position (rear)" is a position advanced from the original mounting position by a distance corresponding to "1 pulse period".

Since the response time can be regarded as fixed, the position of the workpiece 60 at the time point of mounting the fitting member 70 depends on the timing at which the counter unit 98 performs a prescribed output to the actuator 40. The counter unit 98 changes the start position (target value) to be compared with the position (actual measurement value) of the workpiece, thereby adjusting the output timing, which is the position of the workpiece 60 at the time point when the mounting member 70 is mounted.

Here, the moving distance of the workpiece 60 corresponding to "1 cycle amount of the pulse signal (i.e., 1 pulse cycle)" is fixed. Therefore, the counter unit 98 that adjusts the output timing (the position of the workpiece 60 at the time point when the mounting member 70 is mounted) according to the start position can adjust the position of the workpiece 60 only by an integral multiple of the distance corresponding to "1 pulse period".

That is, the counter unit 98 that adjusts the output timing by changing the target value cannot make the adjustable timing smaller than the period of the pulse signal, and if the period of the pulse signal is long, the timing error becomes large. Further, when the period of the pulse signal changes, the counter unit 98 needs to change the target value to be compared with the actual measurement value in order to maintain the same output timing before and after the period change, which is inconvenient for the user.

(conventional example relating to liquid filling application)

Fig. 13 is a diagram showing a conventional technique for a process of filling a liquid into a workpiece (hereinafter, also referred to as a "liquid filling application"). As shown in fig. 13 a, the counter unit 98 uses the pulse signal from the flowmeter 31 (pulse signal generating device), that is, uses the count value to grasp the filling amount (measured value) of the liquid with which the workpiece is filled.

When the counter unit 98 determines that "the amount of liquid filled in the workpiece (filled amount, actual measurement value) has reached the valve closing operation start amount (target value)", the output to the valve 41 (actuator) (comparison matching output) is executed. That is, when the counter unit 98 determines that "the count value matches the comparison count value set in association with the valve closing operation start amount", the output to the valve 41 is executed to close the valve 41 and stop the filling of the liquid into the workpiece.

Here, as shown in fig. 13 (B), a response time is required from the time when the counter unit 98 determines that the "filling amount has reached the valve closing operation start amount" to the time when the valve 41 is closed and the filling is stopped. The response time is a time including "time required for the circuit to respond" and "time required for the mechanical response", and is considered to be fixed. That is, the time required for the circuit to respond is required from the time when the "count value and the comparison count value have matched" is determined until the valve 41 receives the output from the counter unit 98 at the time when the "match" is determined. Further, a time required for mechanical response is required until the valve 41 receives the output from the counter unit 98 and executes the processing corresponding to the output from the counter unit 98 from the valve 41. That is, the time required for the mechanical response is required until the counter unit 98 performs the output to the valve 41 to close the valve 41 and stop the filling.

In fig. 13 (B), the filling amount into the workpiece at the time point when the response time has elapsed from the time point when it is determined that the "count value has matched the comparison count value" is referred to as "filling amount actual value" based on the meaning of the actual value of the filling amount. The actual value of the filling amount can also be understood as the actual filling amount at the point in time when the valve 41 is closed and the filling is stopped. The "target filling amount" indicates a predetermined ideal filling amount to the workpiece at the time point when the valve 41 is closed and the filling is stopped.

As shown in fig. 13 (B), if the filling amount actual value is larger than the filling amount target value, that is, the filling amount is excessive, the counter unit 98 decreases the value of the comparison count value, thereby decreasing the value of the filling amount actual value.

However, the "resolution of the adjustable filling amount" of the counter unit 98 is at most 1 pulse period amount of the flow rate, that is, the counter unit 98 can only adjust the actual value of the filling amount by an integral multiple of the flow rate equivalent to "1 pulse period". As a result, the following may occur: as shown in fig. 13B, the counter unit 98 decreases the value of the comparison count value, and can perform filling only by a filling amount that does not satisfy the filling amount target value (the actual value of the filling amount is less than the filling amount target value).

Since the response time can be regarded as fixed, the amount of filling to the work at the time point when the valve 41 is closed depends on the timing at which the counter unit 98 performs the predetermined output to the valve 41. The counter unit 98 changes a valve closing operation start amount (target value) to be compared with a filling amount (actual measurement value) to the workpiece, thereby adjusting an output timing which is an actual filling amount value.

Here, the amount of filling the workpiece corresponding to "1 cycle amount of the pulse signal (i.e., 1 pulse cycle)" is fixed. Therefore, the counter unit 98 that adjusts the output timing (i.e., the actual filling amount value) according to the valve closing operation start amount (target value) can adjust the actual filling amount value only by an integral multiple of the filling amount corresponding to "1 pulse period".

That is, the counter unit 98 that adjusts the output timing by changing the target value cannot make the adjustable timing smaller than the period of the pulse signal, and if the period of the pulse signal is long, the timing error becomes large. Further, when the period of the pulse signal changes, the counter unit 98 needs to change the target value to be compared with the actual measurement value in order to maintain the same output timing before and after the period change, which is inconvenient for the user.

The conventional counter unit whose details are described with reference to fig. 12 and 13 can be organized as follows. That is, in general, when the counter unit determines that an actually measured value measured using a count value (the number of pulses of a pulse signal) matches a target value, the control of an actuator such as a valve, that is, a predetermined output to the actuator is performed.

Further, a response time is required from a time point when the counter unit determines that the "actual measurement value matches the target value" to a time point when the workpiece state corresponding to the output is realized by the output from the counter unit to the actuator. That is, until the workpiece reaches a desired state after the "actual measurement value matches the target value", a timing error occurs in the total time (response time) of the "time required for circuit response" and the "time required for mechanical response". The "response time" is also sometimes expressed as a "delay time".

The conventional counter unit increases or decreases a target value compared with (i.e., determined to match) an actual measurement value, thereby eliminating the influence of timing errors. However, the target value can be increased or decreased only by an integral multiple of the movement distance/filling amount corresponding to "1 pulse period", that is, the conventional counter unit has a problem that the resolution in adjusting the output timing is the pulse period. Therefore, particularly when the pulse period is long, the conventional counter unit cannot finely adjust the output timing, and the timing error becomes large. Further, since the response time is fixed regardless of the pulse period, when the pulse period changes, the conventional counter unit cannot maintain the output timing unless the target value is increased or decreased in accordance with the changed pulse period, and thus, there is a problem of low user convenience.

An embodiment of the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a counter unit or the like capable of adjusting timing of output to an actuator performed when it is determined that an actual measurement value measured using the number of pulses of a pulse signal matches a target value, regardless of a period of the pulse signal.

Means for solving the problems

In order to solve the problem, a counter unit of an embodiment of the present invention includes: a measuring unit for counting the number of pulses of the pulse signal to measure an actual measurement value; a comparison unit configured to determine whether the actual measurement value measured by the measurement unit matches a target value; and an output unit configured to output the actual measurement value to an actuator when the comparison unit determines that the actual measurement value matches the target value, wherein the output unit includes an output delay unit configured to adjust timing of the output to a point in time that is independent of a period of the pulse signal and is indicated by a timing adjustment value after a point in time when the comparison unit determines that the actual measurement value matches the target value has elapsed.

In order to solve the problem, a method for controlling a counter unit according to an embodiment of the present invention includes: a measuring step of counting the number of pulses of the pulse signal to measure an actual measurement value; a comparison step of determining whether the measured value measured in the measurement step matches a target value; and an output step of executing an output to an actuator when it is determined in the comparison step that the actual measurement value matches the target value, the output step including an output delay step of adjusting a timing of the output to a time point that is independent of a cycle of the pulse signal and that is indicated by a timing adjustment value from a time point at which it is determined in the comparison step that the actual measurement value matches the target value.

ADVANTAGEOUS EFFECTS OF INVENTION

According to an embodiment of the present invention, there is an effect that the counter unit can adjust the timing of output to the actuator independently of the cycle of the pulse signal.

Drawings

Fig. 1 is a block diagram showing a main part configuration of a counter unit and the like according to embodiment 1 of the present invention.

Fig. 2 is a diagram showing an overview of the entire control system including the counter unit of fig. 1.

Fig. 3 is a flowchart showing an example of processing executed in the entire control system of fig. 2.

Fig. 4 is a diagram illustrating timing adjustment values set by the counter unit of fig. 1.

Fig. 5 is a diagram showing a connection example between the counter unit of fig. 1 and a Programmable Logic Controller (PLC) of fig. 1.

Fig. 6 is a diagram illustrating details of the timing adjustment value set by the counter unit of fig. 1.

Fig. 7 is a diagram illustrating the performance and the like of each device included in the control system of fig. 2.

Fig. 8 is a diagram for explaining the performance and the like of each device other than the device shown in fig. 7 included in the control system of fig. 2.

Fig. 9 is a diagram showing an outline of a method of updating timing adjustment values in an assembly application.

Fig. 10 is a diagram showing a specific example of a method for detecting an actual mounting position with respect to a mounting application.

Fig. 11 is a diagram showing a specific example of a method for detecting an actual filling amount in relation to a liquid filling application.

Fig. 12 is a diagram showing a conventional technique for processing (assembly application) for assembling parts to a workpiece.

Fig. 13 is a diagram showing a conventional technique for a process of filling a liquid into a workpiece (liquid filling application).

Detailed Description

[ embodiment mode 1 ]

An embodiment of one aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described below with reference to fig. 1 to 13. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and description thereof will not be repeated. In the present embodiment, for example, the counter unit 10 is described as a typical example of the counter unit. To facilitate understanding of the counter unit 10 according to an embodiment of the present invention, an outline of the control system 1 including the counter unit 10 will be described with reference to fig. 2.

Application example § 1

(Overall overview of control System)

Fig. 2 is a diagram showing an overview of the entire control system 1 including the counter unit 10. As shown in fig. 2 a, the control system 1 includes a counter unit 10 and a Programmable Logic Controller (PLC) 20 as a control device (Controller). As shown in fig. 2 a, the control system 1 may further include a sensor (pulse signal generating device) that generates a pulse signal such as the encoder 30 and an actuator 40.

The counter unit 10 is communicably connected to the PLC20 via, for example, a field network, and transmits and receives data to and from the PLC20 at fixed communication cycles, specifically, at control cycles of the PLC 20. For example, the counter unit 10 receives the target value and the timing adjustment value Ta from the PLC20 every control cycle of the PLC20, and transmits information indicating the position of the workpiece 60 grasped using the count value to the PLC20 every control cycle of the PLC 20.

The counter unit 10 is communicably connected to the encoder 30 and the actuator 40, respectively. The counter unit 10 receives a pulse signal (pulse wave) generated by the encoder 30 from the encoder 30 as an input, and counts the number of pulses of the received pulse signal, that is, measures the state of the workpiece or the like using the count value. The counter unit 10 calculates the moving distance of the conveyor, i.e., grasps the position of the workpiece on the conveyor, based on, for example, a pulse signal from an encoder 30 attached to the conveyor. In the following description, "the state of the workpiece or the like (for example, the position, size, weight, and the like of the workpiece or the like)" measured by the counter unit 10 by counting the number of pulses of the pulse signal is also referred to as "an actual measurement value".

When the moving distance of the conveyor, i.e., the position of the workpiece 60, coincides with the target value received from the PLC20, the counter unit 10 performs the following processing. That is, the counter unit 10 waits for a time indicated by the timing adjustment value Ta received from the PLC20 from the time when it is determined that the position of the workpiece 60 matches the target value, and then outputs a predetermined signal to the actuator 40. In the following description, the output of the predetermined signal to the actuator 40, which is performed by the counter unit 10 that determines that the actual measurement value matches the target value, is also referred to as "comparison matching output". When the counter unit 10 determines that the actual measurement value matches the target value, it outputs a signal indicating that the position of the workpiece 60 matches the target value to the actuator 40, for example.

The counter unit 10 outputs a predetermined signal to the actuator 40, thereby causing the actuator 40 to execute a predetermined process (operation), that is, a process corresponding to the predetermined signal. In particular, the counter unit 10 adjusts the timing of output to the actuator 40, thereby adjusting the timing at which the actuator 40 executes a predetermined process, that is, the state of the workpiece is set to a desired state at a desired timing.

The PLC20 is a control device (controller) that controls the entire control system 1, and is communicably connected to the counter unit 10. For example, a display unit and an operation unit, not shown, may be connected to the PLC 20. The display unit includes a liquid crystal panel or the like that can display an image, and typically, the operation unit includes a touch panel, a keyboard, a mouse, and the like.

The PLC20 transmits the target value and the timing adjustment value Ta to the counter unit 10, and particularly transmits the target value and the timing adjustment value Ta to the counter unit 10 at regular communication cycles so that the actuator 40 performs a predetermined process at a predetermined timing.

The encoder 30 is mounted on a conveyor, for example, and generates a pulse signal corresponding to the amount of movement of the conveyor, that is, the amount of movement of the workpiece 60. The encoder 30 outputs a pulse wave to the counter unit 10 every time the conveyor (i.e., the workpiece 60) moves by a prescribed amount.

The actuator 40 is connected to the counter unit 10. When receiving the output from the counter unit 10, the actuator 40 executes a predetermined operation (for example, an operation of attaching a component held by the actuator 40 to the workpiece 60).

As shown in fig. 2 (B), that is, until the actuator 40 receives the output from the counter unit 10 at the time when the "actual measurement value" matches the target value, it takes time for the circuit to respond. That is, the time at which the actuator 40 can receive the output from the counter unit 10 is a time after the time at which the time required for the circuit response has elapsed from the time at which the counter unit 10 determines that the "actual measurement value matches the target value".

Further, a time required for the mechanical response is required between a time point when the actuator 40 executes the processing corresponding to the output from the counter unit 10 and a time point when the actuator 40 receives the output from the counter unit 10. That is, the time point at which the actuator 40 can execute the processing corresponding to the output from the counter unit 10 is a time point after the time point at which the output from the counter unit 10 is received by the actuator 40 has elapsed by the time required for the mechanical response.

Therefore, the actuator 40 can execute the processing corresponding to the output from the counter unit 10 at the fastest time point, and also at the time point when the "response time" in fig. 2 (B) has elapsed from the time point at which the counter unit 10 determines that the "actually measured value matches the target value". The "response time" in fig. 2 (B) is a total value of the "time required for the circuit to respond" and the "time required for the mechanical response", and is also referred to as "delay".

That is, when the output to the actuator 40 is executed after the "actual measurement value matches the target value" is determined, the counter unit 10 cannot cause the actuator 40 to execute the predetermined process at the time point of the target value (i.e., at the time point when the actual measurement value matches the target value).

Therefore, in order to cause the actuator 40 to execute a predetermined process at the time point of the target value, the control system 1 changes the value determined to match the actual measurement value to the "correction target value", and causes the counter unit 10 to execute the standby process using the "timing adjustment value Ta".

That is, when it is determined that the "actual measurement value matches the correction target value", the counter unit 10 waits for the time indicated by the timing adjustment value Ta and then outputs the timing adjustment value Ta to the actuator 40. That is, the counter unit 10 outputs the output to the actuator 40 at a time point when the time indicated by the timing adjustment value Ta has elapsed from the time point when the "actual measurement value matches the correction target value" is determined.

Thus, the time point at which the actuator 40 receives the output from the counter unit 10 is the time point at which the total time of the time indicated by the timing adjustment value Ta and the time required for circuit response has elapsed from the time point at which the "actually measured value matches the correction target value" is determined. Further, the time point at which the actuator 40 executes the processing corresponding to the output from the counter unit 10 is a time point at which the output from the counter unit 10 is received from the actuator 40 has elapsed the time required for the mechanical response.

Therefore, the actuator 40 executes a predetermined process at a point in time when the total time of the time indicated by the timing adjustment value Ta and the response time has elapsed from the point in time when the counter unit 10 determines that the "actual measurement value matches the correction target value". That is, as shown in fig. 2 (B), the actuator 40 executes predetermined processing at the time point of the target value.

As described above, the control system 1 can adjust the execution timing of the comparison matching output of the counter unit 10 by the fixed-period communication (cyclic communication) between the counter unit 10 and the PLC 20. That is, the counter unit 10 adjusts the execution timing of the comparison and matching output to the actuator 40 using the target value (correction target value) periodically received from the PLC20 and the timing adjustment value Ta. Specifically, the counter unit 10 sets the execution timing of the comparison matching output as a time point when a time indicated by the timing adjustment value Ta has elapsed from a time point when the actual measurement value measured using the pulse signal is determined to match the target value (correction target value).

Here, the conventional counter units shown in fig. 12 and 13 adjust the timing of execution of the comparison matching output only based on the target value for comparison with the actual measurement value (i.e., determination of matching with the actual measurement value), without using the timing adjustment value Ta. The target value can be increased or decreased only by an integral multiple of the actual measurement value (movement distance/filling amount) corresponding to "1 pulse period Tp (1 period of the pulse signal)". Therefore, in the conventional counter unit, the resolution in adjusting the execution timing of the comparison matching output is the pulse period Tp.

In contrast, the counter unit 10 adjusts the execution timing of the comparison matching output using the timing adjustment value Ta received from the PLC20 in addition to the target value. The timing adjustment value Ta is unrelated to the period Tp of the pulse signal. Therefore, the counter unit 10 can adjust the comparison matching output timing independently of the period Tp of the pulse signal, that is, independently of the period Tp of the pulse signal, and thus can control the comparison matching output timing with high accuracy.

In the control system 1 described with reference to fig. 2, when the counter unit 10 determines that the position (actually measured value) of the workpiece measured by using the pulse signal from the encoder 30 matches a predetermined position (target value), the output to the actuator 40 is executed.

However, the state of the workpiece measured by the counter unit 10 using the pulse signal is not limited to the position of the workpiece. The counter unit 10 may measure a filling amount (actual measurement value) of the liquid filled into the workpiece using a pulse signal from a flow meter as a pulse signal generating device, for example. When the counter unit 10 determines that the amount of filling the workpiece measured using the pulse signal matches a predetermined filling amount (filling amount corresponding to a target value), the predetermined signal may be output to the actuator 40 such as a valve for filling the workpiece with the liquid.

For example, a flow meter that outputs a pulse output signal proportional to the flow rate of the liquid in the pipe is disposed between the pipe, which is a flow path through which the liquid flows, and a valve (actuator) that is connected to the pipe and is capable of controlling the filling rate of the liquid for filling. The counter unit 10 counts the number of pulses of a pulse signal from the flowmeter to measure the amount of liquid (actual measurement value) filled into a workpiece serving as a container to be filled, the amount being controlled by opening and closing of a valve. When it is determined that the amount of filling the workpiece matches a predetermined filling amount (a filling amount corresponding to a target value), the counter unit 10 outputs a predetermined signal to the valve to close the valve, thereby stopping filling the workpiece with the liquid. In particular, when the counter means determines that the amount of filling into the workpiece matches the predetermined amount of filling, the timing at which the time indicated by the timing adjustment value Ta has elapsed from this point in time is set as the execution timing of the comparison match output to the valve.

Construction example 2

The control system 1 described in the outline so far with reference to fig. 2 will be described in detail below. The control system 1 (particularly, the counter unit 10 and the PLC20) described in detail with reference to fig. 1 and the like is summarized as follows.

That is, the counter unit 10 includes: a measuring unit 130 for counting the number of pulses of the pulse signal to measure an actual measurement value; a determination unit 140 (comparison unit) that determines whether the actual measurement value measured by the measurement unit 130 matches a target value; and an output unit 150 that outputs (compares and outputs) the actual measurement value with the target value to the actuator 40 when the determination unit 140 determines that the actual measurement value matches the target value. The output unit 150 includes an output delay unit 160, and the output delay unit 160 adjusts the timing of the output to a point in time that is independent of the period Tp of the pulse signal and is indicated by the timing adjustment value Ta from a point in time when the determination unit 140 determines that the actual measurement value matches the target value.

According to the above configuration, the counter unit 10 receives the pulse signal as an input from a pulse signal generating device that generates the pulse signal according to a detected amount, such as the encoder 30 or a flow meter, and measures the actual measurement value from the received pulse signal. When the counter unit 10 determines that the actual measurement value matches the target value, the output is performed at a time point when a time period independent of the period Tp of the pulse signal, indicated by the timing adjustment value Ta, has elapsed from the time point at which the actual measurement value matches the target value.

Conventionally, there is known a technique of: the timing of the output is adjusted by increasing or decreasing a target value for a counter unit that executes the output when it is determined that an actual measurement value measured by counting the number of pulses of the pulse signal matches the target value.

Here, the target value can be increased or decreased only by an integral multiple of the actual measurement value corresponding to the "period of the pulse signal (pulse period Tp)". Therefore, in the conventional counter unit that adjusts the output timing only according to the target value, the resolution related to the adjustment of the output timing is limited to the pulse period Tp. In particular, when the pulse period Tp is long, the conventional counter unit cannot finely adjust the output timing, and the timing error becomes large. Further, since the response time is fixed regardless of the pulse period Tp, when the pulse period Tp changes, the conventional counter unit cannot maintain the output timing unless the target value is increased or decreased in accordance with the changed pulse period Tp, and thus the user convenience is low.

In such a conventional counter unit, the counter unit 10 adjusts the timing of the output using the timing adjustment value Ta indicating a time (standby time) independent of the period Tp of the pulse signal, in addition to the target value. That is, the counter unit 10 adjusts the timing of the output to a point in time that is independent of the period Tp of the pulse signal and is indicated by the timing adjustment value Ta after the point in time at which it is determined that the actual measurement value matches the target value.

Therefore, the counter unit 10 exerts the following effects: the timing of the output can be adjusted by using the timing adjustment value Ta independently of the period Tp of the pulse signal, that is, independently of the period Tp of the pulse signal. In particular, since the time indicated by the timing adjustment value Ta is independent of the period Tp of the pulse signal, the counter section 10 can finely adjust the timing of the output even when the pulse period Tp is long. Even when the pulse period Tp changes, the counter unit 10 can easily adjust the timing of the output by changing the value of the timing adjustment value Ta by the amount of change in the pulse period Tp, and thus the user convenience is high.

In the counter unit 10, the output unit 150 includes a hardware-based logic circuit, and the time indicated by the timing adjustment value Ta is an integral multiple of the clock of the logic circuit.

According to the above configuration, in the counter unit 10, the output unit 150 includes a hardware-based logic circuit. For example, the output unit 150 may be implemented using at least one of a Field Programmable Gate Array (FPGA), a Complex Programmable Logic Device (CPLD), and an Application Specific Integrated Circuit (ASIC). In the counter unit 10, the timing adjustment value Ta is an integral multiple of the clock of the logic circuit.

Here, by implementing the output unit 150 using a hardware-based logic circuit, the delay amount can be made smaller than in the case where the output unit 150 is implemented using software. That is, by implementing the output unit 150 by a logic circuit based on hardware, it is possible to set a smaller value for the time (standby time) indicated by the timing adjustment value Ta than in the case where the output unit 150 is implemented by software. Further, by implementing the output unit 150 by a logic circuit based on hardware, it is possible to suppress variation in delay as compared with the case where the output unit 150 is implemented by software.

Therefore, the counter unit 10 exerts the following effects: when it is determined that the actual measurement value matches the target value, the output to the actuator 40 can be performed with a shorter standby time than when the output unit 150 is implemented by software. Moreover, the counter unit 10 exerts the following effects: as compared with the case where the output unit 150 is implemented by software, variation in delay can be suppressed.

The counter unit 10 further includes a communication unit 110, and the communication unit 110 receives the target value and the timing adjustment value Ta from a PLC20 (control device) that performs input/output processing of ON/OFF (ON/OFF) data at a predetermined control cycle.

According to this configuration, the counter unit 10 receives the target value and the timing adjustment value Ta from the PLC20, and adjusts the timing of the output (comparison matching output) using the received target value and the timing adjustment value Ta.

Here, the communication method between the counter unit 10 and the PLC20 is not particularly limited. The counter unit 10 and the PLC20 may also be communicatively connected to each other, for example, via a field network, via which the counter unit 10 receives the target value and the timing adjustment value Ta from the PLC 20. Also, the counter unit 10 may also be integrally formed with the PLC20, i.e., may also be communicably connected to the PLC20 via an internal bus. At this time, the counter unit 10 may also receive the target value and the timing adjustment value Ta from the PLC20 via an internal bus.

For example, the counter unit 10 repeatedly receives the target value and the timing adjustment value Ta from the PLC20 every the control cycle, and adjusts the timing of the output using the received target value and the received timing adjustment value Ta.

Therefore, the counter unit 10 exerts the following effects: the actual measurement value measured by the own device is compared with the target value received from the PLC20, and the timing of the output can be adjusted using the timing adjustment value Ta received from the PLC 20. That is, the user can adjust the timing of the output using the target value and the timing adjustment value Ta that the PLC20 transmits to the counter unit 10 (e.g., periodically).

The timing adjustment value Ta is updated using a "feedback value indicating the actual state of the workpiece 60 or the like by the actuator 40 that has received the output (comparison matching output) from the counter unit 10".

According to the structure, the counter unit 10 exerts the following effects: the timing of the output can be adjusted with high accuracy by the timing adjustment value Ta updated to an appropriate value using the feedback value relating to the output to the actuator 40.

The timing adjustment value Ta is updated using a difference between a "reference value indicating a predetermined ideal state of the workpiece 60 or the like to be realized by the actuator 40 that has received the output" and a value calculated by performing statistical processing on a plurality of the feedback values.

According to the above configuration, the counter unit 10 adjusts the timing of the output by using the timing adjustment value Ta updated to an appropriate value by using the difference between the reference value and the value calculated by statistically processing the plurality of feedback values.

Here, by updating the timing adjustment value Ta using a value calculated by statistically processing a plurality of the feedback values, even when the feedback values temporarily exhibit an abnormal value, the influence of such an abnormal value on the timing adjustment value Ta can be suppressed.

Therefore, the counter unit 10 exerts the following effects: even when the feedback value temporarily exhibits an abnormal value, the timing of the output can be adjusted with high accuracy by using the timing adjustment value Ta updated to an appropriate value while suppressing the influence from such an abnormal value.

The counter unit 10 and the like described in the summary so far are described below with reference to fig. 1, and the details of the configuration thereof are described below with reference to fig. 3, and the processing performed by the counter unit 10 and the like is described below.

(details of counter unit)

Fig. 1 is a block diagram showing a configuration of a main part of a counter unit 10 and the like included in a control system 1. As shown in fig. 1, the counter unit 10 is a device for adjusting the execution timing of a predetermined operation to be executed by an actuator, and includes, as functional blocks, a communication unit 110, a setting unit 120, a measurement unit 130, a determination unit 140, and an output unit 150.

The communication unit 110 receives the target value and the timing adjustment value Ta from the PLC20, and in particular, repeatedly receives the target value and the timing adjustment value Ta from the PLC20 every control cycle of the PLC 20. The communication unit 110 notifies the setting unit 120 of the target value and the timing adjustment value Ta received from the PLC 20.

The communication unit 110 is implemented using an Integrated circuit such as a communication Integrated Circuit (IC). Specifically, the communication unit 110 may be implemented using at least one of a Field Programmable Gate Array (FPGA), a Complex Programmable Logic Device (CPLD), and an Application Specific Integrated Circuit (ASIC).

Setting unit 120 notifies determination unit 140 and output unit 150 of the target value and timing adjustment value Ta received by communication unit 110 from PLC 20. Specifically, setting unit 120 notifies determination unit 140 of the target value received by communication unit 110 from PLC20, and also notifies output unit 150 of timing adjustment value Ta received by communication unit 110 from PLC 20.

The measuring unit 130 receives the pulse signal generated by the pulse signal generating device such as the encoder 30 from the pulse signal generating device, and counts the number of pulses (count value) of the received pulse signal to measure the actual measurement value such as the position and filling amount of the workpiece. The measurement unit 130 notifies the determination unit 140 of an actual measurement value measured using the pulse signal.

Determination unit 140 determines whether or not the actual measurement value measured by measurement unit 130 using the pulse signal matches the target value notified from setting unit 120 (i.e., the target value acquired from PLC 20). When the determination unit 140 determines that the "actual measurement value matches the target value", the determination result of "the actual measurement value matches the target value" is notified to the output unit 150.

The setting Unit 120 is realized by software using, for example, a Central Processing Unit (CPU) or a microprocessor Unit (MPU). The measurement unit 130 and the determination unit 140 are realized by hardware, and may be realized by, for example, a counter function inside an MPU, or may be realized by an IC such as an FPGA or an ASIC.

Upon receiving the notification of the determination result of "the actual measurement value matches the target value" from the determination unit 140, the output unit 150 outputs a predetermined signal (for example, a signal indicating "the actual measurement value matches the target value") to the actuator 40, that is, performs a predetermined output (comparison matching output). The output unit 150 executes the comparison matching output, thereby causing the actuator 40 to execute a predetermined process (operation) corresponding to the comparison matching output.

In particular, the output unit 150 adjusts the timing of executing the predetermined processing (operation) by the actuator 40 by adjusting the timing of executing the comparison matching output, and specifically, executes the comparison matching output at the following timing. That is, the output unit 150 waits until the time (waiting time) set by the output delay unit 160 elapses from the time when the determination result "the actual measurement value matches the target value" is notified from the determination unit 140, and performs the comparison matching output at the time when the waiting time elapses. The output unit 150 includes an output delay unit 160 for setting the standby time.

The output delay unit 160 sets a "standby time" which is a time interval from a time point when the output unit 150 receives a notification of a determination result that the "actual measurement value matches the target value" until a time point when the output unit 150 performs a comparison matching output (output of the predetermined signal to the actuator 40). The output delay unit 160 sets the time indicated by the timing adjustment value Ta notified from the setting unit 120 (i.e., the timing adjustment value Ta acquired from the PLC20) as the standby time, and sets the timing adjustment value Ta as the standby time, for example.

As described above, the timing adjustment value Ta is a signal (data) received from the PLC20, and is a signal indicating a time independent of the period of the pulse signal received by the measurement unit 130 from the pulse signal generation device such as the encoder 30, that is, independent of the period of the pulse signal. Therefore, the output delay unit 160 can set the standby time to a time independent of the period of the pulse signal using the timing adjustment value Ta.

The output unit 150 may be configured as hardware by a logic circuit formed on an Integrated Circuit (IC) chip, for example, and may be implemented by using at least one of an FPGA, a CPLD, and an ASIC. The output delay unit 160 may be implemented by a function inside the MPU (or inside the CPLD) constituting the output unit 150, or may include hardware such as an FPGA or an ASIC.

The hardware constituting the output unit 150 may be different from the hardware constituting the communication unit 110, and may be different from a CPU (or MPU) that realizes the setting unit 120, the measurement unit 130, and the determination unit 140. That is, the counter unit 10 may include three hardware components, i.e., a communication IC (communication unit 110), a CPU (or MPU) that realizes the setting unit 120, the measurement unit 130, and the determination unit 140, and hardware that constitutes the output unit 150.

(details of PLC)

The PLC20 is a control device that performs input/output processing of on/off data at a predetermined control cycle, and transmits a target value and a timing adjustment value Ta to the counter unit 10 at a predetermined control cycle, for example.

In fig. 1, the PLC20 is connected to the imaging device 50 (state detection device), that is, the control system 1 shown in fig. 1 includes a counter unit 10, a PLC20, and the imaging device 50.

The PLC20 acquires, from the imaging device 50, data (captured image data) indicating the actual state of the workpiece 60 achieved by the actuator 40 that received the comparison matching output from the counter unit 10, as a feedback value relating to the comparison matching output. In particular, the PLC20 repeatedly acquires captured image data as a feedback value from the imaging device 50 every control cycle of the PLC 20.

As shown in fig. 1, the PLC20 includes a storage unit 210 and a timing calculation unit 220 (update unit) as functional blocks. The PLC20 may include an acquisition unit, not shown, for acquiring captured image data from the imaging device 50 in addition to the above-described functional blocks, but in order to ensure the simplicity of description, a configuration that is not directly related to the present embodiment is omitted from the description and the block diagram. However, the PLC20 may also include the omitted configuration, depending on the actual implementation. The timing calculation Unit 220 can be implemented by, for example, a Central Processing Unit (CPU) or the like reading a program stored in a storage device (storage Unit 210) implemented by a Read Only Memory (ROM), a Non-Volatile Random Access Memory (NVRAM), or the like, into a Random Access Memory (RAM), or the like (not shown). The timing calculation unit 220 in the PLC20 will be described below.

The timing calculation unit 220 specifies "the actual position (feedback value) of the workpiece 60 by the actuator 40 that has received the comparison and matching output from the counter unit 10" from the captured image data acquired as the feedback value from the imaging device 50. The timing calculation unit 220 updates the timing adjustment value Ta using information (feedback value) indicating the determined actual position of the workpiece 60.

For example, the timing calculation unit 220 specifies a plurality of feedback values from a plurality of pieces of captured image data acquired from the imaging device 50, and calculates an average value of the specified plurality of feedback values. The timing calculation unit 220 updates the timing adjustment value Ta using the difference between the calculated average value and a reference value indicating "a predetermined ideal position (state) of the workpiece 60 to be achieved by the actuator 40 that has received the comparison and matching output". The update of the timing adjustment value Ta using the feedback value by the timing calculation unit 220 will be described in detail below with reference to fig. 9 and the like.

The PLC20 transmits the timing adjustment value Ta and the target value updated by the timing calculation unit 220 to the counter unit 10. The counter unit 10 performs a comparison and matching output using the latest timing adjustment value Ta (the timing adjustment value Ta updated by the timing calculation unit 220) received from the PLC20 and a target value.

The storage unit 210 is a storage device that stores various data used by the PLC 20. The storage unit 210 may store, in a non-transitory manner, (1) a control program, (2) an Operating System (OS) program, (3) an application program for executing various functions of the PLC20, and (4) various data read when the application program is executed, which are executed by the PLC 20. The data (1) to (4) are stored in a nonvolatile storage device such as a Read Only Memory (ROM), a flash Memory, an Erasable Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), and a Hard Disk Drive (HDD)). The PLC20 may include a temporary storage unit not shown. The temporary storage unit is a so-called work Memory that temporarily stores data used for calculation, calculation results, and the like during various processes performed by the PLC20, and includes a volatile storage device such as a Random Access Memory (RAM). Which data is stored in which storage device is appropriately determined according to the purpose of use, convenience, cost, physical limitations, and the like of the PLC 20. The storage unit 210 further stores a reference value and a target value.

The reference value is data indicating "a predetermined ideal state of the workpiece 60 or the like to be realized by the actuator 40 that has received the comparison and matching output from the counter unit 10". The reference value is, for example, a set mounting position indicating "an ideal position of the workpiece 60 at the time point when the mounting member 70 is mounted by the actuator 40" in the mounting application. In the liquid filling application, the "ideal weight/cumulative amount of the workpiece at the time point when the valve is closed and the filling is stopped (i.e., the ideal filling amount)" may be cited as an example of the reference value.

The target value is a value which is transmitted to the counter unit 10 in order to achieve the "predetermined ideal state of the workpiece 60 or the like" corresponding to the reference value, and which is determined by the counter unit 10 to coincide with the actual measurement value. Here, the time point when the total time of the standby time and the response time indicated by the timing adjustment value Ta has elapsed from the time point when it is determined that the target value and the actual measurement value coincide with each other is the time point when the workpiece 60 or the like is in a predetermined ideal state corresponding to the reference value. That is, an actual measurement value (for example, a corrected target value in fig. 2 (B)) corresponding to a time point "a total time of the standby time and the response time indicated by the timing adjustment value Ta" is set as a target value from a time point "when the workpiece 60 or the like is in a predetermined ideal state corresponding to the reference value".

The target value is, for example, an operation start position in the assembly application, and the counter unit 10 executes the comparison and matching output after waiting time indicated by the standby timing adjustment value Ta from the time point when it is determined that "the position (actual measurement value) of the workpiece 60 has reached the operation start position". The target value is, for example, a valve closing operation start amount in the liquid filling application, and the counter unit 10 waits for a waiting time indicated by the timing adjustment value Ta from a time point when it is determined that "the filling amount (actually measured value) matches the valve closing operation start amount" and then performs a comparison matching output.

That is, the PLC20 (control device) includes a timing calculation unit 220 (updating unit) and transmits the timing adjustment value Ta and the target value updated by the timing calculation unit 220 to the counter unit 10. The timing calculation unit 220 updates the timing adjustment value Ta using "a value indicating an actual state of the workpiece 60 or the like realized by the actuator 40 that has received the output from the counter unit 10" as a feedback value relating to the output.

According to this configuration, the PLC20 updates the timing adjustment value Ta to an appropriate value using the feedback value, and transmits the updated timing adjustment value Ta and the target value to the counter unit 10.

Thus, the PLC20 has the following effects: by transmitting the timing adjustment value Ta updated to an appropriate value and the target value, the timing of the output can be adjusted to an appropriate time point independent of the period Tp of the pulse signal.

Here, the PLC20 may acquire the feedback value from a state detection device implemented using, for example, the imaging device 50 (camera), various sensors (specifically, a displacement sensor, a load cell, a distance measurement device using a laser, or the like), or the like. Also, the PLC20 may be integrally formed with the counter unit 10.

The timing calculation unit 220 updates the timing adjustment value Ta using a difference between a reference value indicating a predetermined ideal state of the workpiece 60 or the like to be realized by the actuator 40 that has received the output and a value calculated by performing statistical processing on a plurality of the feedback values.

According to this configuration, the PLC20 updates the timing adjustment value Ta for adjusting the timing of the output to an appropriate value using the difference between the reference value and the value calculated by statistically processing the plurality of feedback values.

Here, by updating the timing adjustment value Ta using a value calculated by statistically processing a plurality of the feedback values, even when the feedback values temporarily exhibit an abnormal value, the influence of such an abnormal value on the timing adjustment value Ta can be suppressed.

Thus, the PLC20 has the following effects: even when the feedback value temporarily exhibits an abnormal value, the timing adjustment value Ta can be updated to an appropriate value in which the influence from such an abnormal value is suppressed.

(details of imaging device)

The imaging device 50 (state detection device) images the actual state of the workpiece 60, which is realized by the actuator 40 that has received the comparison and matching output from the counter unit 10, and transmits the captured image data to the PLC20 as a feedback value relating to the comparison and matching output. In particular, the photographing device 50 transmits the photographed image data to the PLC20 every time the actual state of the workpiece 60 is photographed.

For example, the imaging device 50 images (detects) the state of the workpiece 60 at the time when the mounting member 70 is mounted by the actuator 40 that has received the comparison matching output (specifically, the position of the workpiece 60 at the time when the mounting member 70 is mounted). The imaging device 50 transmits the captured image data generated by the imaging to the PLC20 as a feedback value relating to the comparison matching output.

(control System Overall)

As illustrated in fig. 1, the control system 1 includes a state detection device such as a counter unit 10, a PLC20, and an imaging device 50. The state detection device detects the actual state of the workpiece 60 or the like realized by the actuator 40 that has received the output from the counter unit 10, and transmits a value indicating the detected actual state of the workpiece 60 as the feedback value to the PLC 20.

According to the configuration, the control system 1 includes the counter unit 10, the PLC20, and the state detection device. In the control system 1, the counter unit 10 adjusts the timing of the output using the timing adjustment value Ta updated by the timing calculation unit 220 of the PLC 20.

The control system 1 achieves the following effects: the timing adjustment value Ta can be updated to an appropriate value using the feedback value detected by the state detection means. Moreover, the control system 1 exerts the following effects: the timing of the output can be adjusted to a timing independent of the period Tp of the pulse signal using the timing adjustment value Ta that has been updated to an appropriate value.

In particular, since the time indicated by the timing adjustment value Ta is independent of the period Tp of the pulse signal, the control system 1 can finely adjust the timing of the output even when the pulse period Tp is long. Even when the pulse period Tp changes, the control system 1 can easily adjust the timing of the output by changing the value of the timing adjustment value Ta by the amount of change in the pulse period Tp, and thus the user convenience is high.

Here, the state detection device can be realized by using, for example, the imaging device 50 (a camera), various sensors (specifically, a displacement sensor, a load cell, a distance measurement device using a laser, or the like), or the like. Also, the counter unit 10 and the PLC20 may be integrally formed.

In the control system 1, the PLC20 updates the timing adjustment value Ta using a difference between a reference value indicating a predetermined ideal state of the workpiece 60 to be realized by the actuator 40 that has received the output and a value calculated by performing statistical processing on a plurality of the feedback values.

According to the above configuration, the control system 1 adjusts the timing of the output using the timing adjustment value Ta updated by the difference between the reference value and the value calculated by statistically processing the plurality of feedback values.

Here, by updating the timing adjustment value Ta using a value calculated by statistically processing a plurality of the feedback values, even when the feedback values temporarily exhibit an abnormal value, the influence of such an abnormal value on the timing adjustment value Ta can be suppressed.

Therefore, the control system 1 achieves the following effects: even when the feedback value temporarily exhibits an abnormal value, the timing of the output can be adjusted with high accuracy by using the timing adjustment value Ta updated to an appropriate value while suppressing the influence from such an abnormal value.

Action example 3

Fig. 3 is a flowchart showing an example of processing executed in the entire control system 1. As shown in fig. 3, the timing calculation unit 220 of the PLC20 acquires a feedback amount (i.e., a feedback value relating to the comparison match output) from a state detection device such as the imaging device 50 as a timing adjustment value update process (S210).

The feedback amount acquired by the PLC20 from the state detection device is data indicating the actual state of the workpiece 60 and the like by the actuator 40 that has received a relatively uniform output in each application. For example, in the case of an assembly application (the control system 1 causes the actuator 40 to execute a process of mounting the assembly member 70 on the workpiece 60), the feedback amount is data indicating an actual assembly position, and details will be described later using fig. 10 and the like. For example, in a liquid filling application (a process in which the control system 1 stops the liquid filling of the valve as an actuator to the workpiece), the feedback amount is data indicating the actual filling amount, and the details will be described with reference to fig. 11 and the like.

The timing calculation unit 220 performs calculation (update) of the timing adjustment value Ta using the feedback amount acquired in S210 (S220). Next, the PLC20 transmits the timing adjustment value Ta calculated (updated) by the timing calculation unit 220 in S220 to the counter unit 10 (S230).

As the timing adjustment value setting process, the communication unit 110 of the counter unit 10 acquires the timing adjustment value Ta transmitted by the PLC20 in S230 (S110), and repeatedly acquires the target value and the latest timing adjustment value Ta, for example, every control cycle of the PLC 20. Next, the output delay unit 160 of the counter unit 10 sets the timing adjustment value Ta acquired in S110 as the standby time, that is, as the output delay (S120, output delay step).

In the counter unit 10, the measuring unit 130 measures actual measurement values such as the position and the filling amount of the workpiece using a pulse signal from a pulse signal generating device such as the encoder 30 (measuring step). The determination unit 140 determines whether or not the actual measurement value measured in the measurement step matches the target value (determination step), and if the actual measurement value is determined to match the target value in the determination step, the output unit 150 performs a comparison and matching output to the actuator 40 (output step). In particular, the output unit 150 performs the comparison matching output at a point in time when the standby time set by the output delay unit 160 in the output delay step (S120) has elapsed since the point in time when the determination step determined that the actual measurement value matches the target value.

The processing performed by the counter unit 10 described above with reference to fig. 3 (in other words, the control method performed by the counter unit 10) can be organized as follows. That is, the process (control method) performed by the counter unit 10 includes: a measuring step of counting the number of pulses of the pulse signal to measure an actual measurement value; a comparison step of determining whether the measured value measured in the measurement step matches a target value; and an output step of outputting to an actuator when it is determined in the comparison step that the actual measurement value matches the target value, the output step including an output delay step (S120), the output delay step (S120) being performed when a time period independent of a cycle of the pulse signal, indicated by a timing adjustment value, has elapsed from a time period when it is determined in the comparison step that the actual measurement value matches the target value.

According to the above configuration, in the control method, the pulse signal is received as an input from a pulse signal generating device that generates the pulse signal in accordance with a detected amount, such as the encoder 30 or a flow meter, and the actual measurement value is measured based on the received pulse signal. In the control method, when it is determined that the actual measurement value matches the target value, the output is performed at a time point when a time period independent of the period Tp of the pulse signal indicated by the timing adjustment value Ta has elapsed from the time point at which the actual measurement value matches the target value.

Conventionally, there is known a technique of: the timing of the output is adjusted by increasing or decreasing a target value for a counter unit that executes the output when it is determined that an actual measurement value measured by counting the number of pulses of the pulse signal matches the target value.

Here, the target value can be increased or decreased only by an integral multiple of the actual measurement value corresponding to the "period of the pulse signal (pulse period Tp)". Therefore, in the conventional counter unit that adjusts the output timing only according to the target value, the resolution related to the adjustment of the output timing is limited to the pulse period Tp. In particular, when the pulse period Tp is long, the conventional counter unit cannot finely adjust the output timing, and the timing error becomes large. Further, since the response time is fixed regardless of the pulse period Tp, when the pulse period Tp changes, the conventional counter unit cannot maintain the output timing unless the target value is increased or decreased in accordance with the changed pulse period Tp, and thus the user convenience is low.

In the conventional counter unit, the timing of the output is adjusted by using the timing adjustment value Ta indicating a time (standby time) independent of the period Tp of the pulse signal, in addition to the target value. That is, in the control method, the timing of the output is adjusted to a point in time that is independent of the period Tp of the pulse signal and is indicated by the timing adjustment value Ta after the point in time at which it is determined that the actual measurement value matches the target value.

Therefore, the control method has the following effects: the timing of the output can be adjusted by using the timing adjustment value Ta independently of the period Tp of the pulse signal, that is, independently of the period Tp of the pulse signal. In particular, since the time indicated by the timing adjustment value Ta is independent of the period Tp of the pulse signal, the control method can finely adjust the timing of the output even when the pulse period Tp is long. In the above control method, even when the pulse period Tp is changed, the timing of the output can be easily adjusted by changing the value of the timing adjustment value Ta by the amount of change in the pulse period Tp, and thus the user convenience is high.

(outline of timing adjustment value)

Fig. 4 is a diagram illustrating the timing adjustment value Ta set by the counter unit 10. The counter unit 10 adjusts the timing of "output to the actuator 40 (comparison matching output)" performed when it is determined that the actual measurement value measured using the pulse signal matches the target value, regardless of the period Tp of the pulse signal, and thus can realize highly accurate control.

Fig. 4 (a) is a diagram illustrating the timing adjustment value Ta set by the counter unit 10 with respect to the process (assembly application) of assembling parts (the assembly member 70 in the example shown in fig. 1) to the workpiece 60.

The counter unit 10 counts the number of pulses of the pulse signal from the encoder 30, that is, calculates the movement amount of the workpiece 60 (in other words, the conveyor) from the count value, and thereby grasps the position (actual measurement value) of the workpiece 60. The counter unit 10 outputs the output to the actuator 40 at a time point when the timing adjustment value Ta (standby time) has elapsed from a time point when it is determined that the workpiece 60 has reached the start position (target value). Then, the actuator 40 mounts (mounts) the mounting member 70 to the workpiece 60 at a time when the "total time of the response time and the timing adjustment value Ta" has elapsed from the time point of determination that the workpiece 60 has reached the start position.

After the counter unit 10 waits for the timing adjustment value Ta for an amount of time, the output to the actuator 40 is performed, whereby the actuator 40 can mount the mounting member 70 at a desired position on the workpiece 60. That is, the counter unit 10 matches the actual mounting position of the mounting member 70 with the ideal mounting position of the mounting member 70 by adjusting the output standby timing to the actuator 40 by the amount of time of the value Ta.

Fig. 4B is a diagram illustrating the timing adjustment value Ta set by the counter unit 10 in relation to the process of filling the workpiece 60 with the liquid (liquid filling application).

The counter unit 10 counts the number of pulses of the pulse signal from the flowmeter as the pulse signal generating device, that is, calculates the filling amount of the liquid into the workpiece 60 from the count value, and thereby grasps the filling amount of the liquid filled into the workpiece 60. The counter unit 10 outputs the output to the valve (i.e., the actuator) at a time point when the timing adjustment value Ta (standby time) has elapsed from a time point when it is determined that the "count value (i.e., the number of pulses of the pulse signal) matches the comparison count value (target value)". Then, when the "total time of the response time and the timing adjustment value Ta" has elapsed from the time point when it is determined that the "count value matches the comparative count value", the valve stops filling of the liquid into the workpiece 60.

The counter unit 10 executes output to the valve after waiting for the amount of time of the timing adjustment value Ta, whereby the valve can make the actual filling amount to the workpiece 60 coincide with the target value (ideal filling amount) of the filling amount to the workpiece 60. That is, the counter unit 10 adjusts the output standby timing to the valve by the amount of time of the value Ta so that the actual value of the amount of filling the workpiece 60 matches the target value of the amount of filling the workpiece 60.

(example of connection of counter Unit and PLC)

The counter unit 10 and the PLC20 may be communicably connected so as to be able to transmit and receive signals (data) to and from each other at regular communication cycles, and the connection method of the counter unit 10 and the PLC20 is not particularly limited.

Fig. 5 is a diagram showing an example of connection between the counter unit 10 and the PLC 20. The counter unit 10 and the PLC20 are communicably connected to each other, and in particular, repeatedly transmit and receive data to and from each other at a predetermined communication cycle (for example, a control cycle of the PLC 20). The counter unit 10 may be in periodic communication with the PLC20, and the bus/network configuration between the counter unit 10 and the PLC20 is not particularly limited.

That is, as shown in fig. 5 (a), the counter unit 10 and the PLC20 may be communicatively connected to each other via a PLC direct bus. That is, the counter unit 10 may be configured integrally with the PLC20 (in other words, as a functional unit of the PLC20), and the counter unit 10 and the PLC20 (particularly, the CPU unit of the PLC20) may be connected by an internal bus.

Further, as shown in fig. 5 (B), the counter unit 10 and the PLC20 may be communicatively connected to each other via a field network. As a field network connecting the counter unit 10 and the PLC20, various industrial ethernet (registered trademark) can be typically used. As the industrial ethernet (registered trademark), for example, EtherCAT (registered trademark), Profinet IRT, MECHATROLINK (registered trademark) -III, Powerlink, SERCOS (registered trademark) -III, CIP Motion, and the like are known, and any of these can be used. Further, a field network other than the industrial ethernet (registered trademark) may be used. For example, when motion control is not performed, DeviceNet, complenet/IP (registered trademark), or the like may be used. In the example shown in fig. 5 (B), in the master-slave control system in which the PLC20 is the master device, the counter unit 10, which is the slave device, is connected to the PLC20 via the field network.

Further, as shown in fig. 5C, the counter unit 10 and the PLC20 may be communicatively connected to each other via an Input Output (IO) terminal internal bus. More precisely, the counter unit 10 and the coupler unit (communication coupler) may be communicatively connected to each other via an IO terminal internal bus (internal bus) to constitute an IO unit as a single body. In the master-slave control system using the PLC20 as a master device, the IO unit including the counter unit 10 and the coupler unit may be connected to the PLC20 as a slave device via a field network.

(details of timing adjustment value)

Fig. 6 is a diagram illustrating details of the timing adjustment value Ta set by the counter unit 10. When the output unit 150 is implemented by hardware, the timing adjustment value Ta depends on the clock frequency of the hardware implementing the output unit 150, that is, the timing adjustment value Ta is an integral multiple of 1 clock. Therefore, for example, in the case where the output section 150 is realized by hardware that operates at a clock frequency of 40MHz, the counter unit 10 can adjust the timing of output to the actuator 40 with a resolution of 1 clock (i.e., 25 ns). That is, when the output unit 150 controls the timing of output to the actuator 40 at a clock of 40MHz, the timing adjustment value Ta can be set at an integer multiple of 1 clock (i.e., 25ns), and the resolution with respect to the output timing of the counter unit 10 is 25 ns.

For example, "25 ns" can be set for the timing adjustment value Ta as the fastest output, and at this time, the counter unit 10 performs output to the actuator 40 25ns after the time point of determination that "the actual measurement value measured using the pulse signal matches the target value".

When "a value delayed by 1 clock from the fastest output" is set for the timing adjustment value Ta, the counter unit 10 outputs the timing adjustment value Ta to the actuator 40 50ns after the time point when it is determined that "the actual measurement value measured using the pulse signal matches the target value".

Similarly, when "a value delayed by 2 clocks from the fastest output" is set for the timing adjustment value Ta, the counter unit 10 outputs to the actuator 40 75ns after the time point of determination of "match".

(example of Performance of each device included in the control System)

Fig. 7 is a diagram illustrating the performance and the like of the PLC20 and the counter unit 10 included in the control system 1. As shown in fig. 7 a, the control cycle (task cycle) of the PLC20 is, for example, "0.5 ms" to "4 ms", and defaults to "1 ms". Here, the "control period" refers to an enable/disable read period of data.

In order to count the number of pulses of the pulse signal by the PLC20, the duty cycle must be equal to or less than half the period Tp of the pulse signal. Therefore, when the task period of the PLC20 is "1 ms", the limit of the period of the pulse signal in which the PLC20 can count the number of pulses is "2 ms (i.e., 500 Hz)".

As shown in fig. 7B, the maximum response frequency of the counter unit 10 is, for example, "500000 Hz" or "4000000 Hz", and the maximum response frequency of the counter unit 10 is very large compared to the readout period (control period) of the PLC 20. The counter unit 10 can count pulse signals of a very high speed cycle compared to pulse signals that the PLC20 can count.

Fig. 8 is a diagram illustrating the performance and the like of the pulse signal generating device such as the encoder 30 and the flow meter included in the control system 1. As shown in fig. 8 a, for example, since the encoder 30 with a resolution of 720 and a rotation speed of 300rpm (5 rotations per 1 second) has a pulse period of "1/3600 ═ 278 μ s" because it has a pulse length of "720 × 5 ═ 3600 pulses" per 1 second, that is, 3600 Hz.

Therefore, if it is desired to adjust the output timing based on the target value alone without using the timing adjustment value Ta, the resolution with respect to the output timing (in other words, timing adjustment) is "278 μ s". In order to increase the resolution of the timing adjustment to a higher level without using the timing adjustment value Ta at the same speed, an encoder having a high resolution (i.e., a higher pulse period) must be used, which means an increase in the acquisition cost of the encoder 30.

As shown in fig. 8 (B), for example, in the case of a flowmeter that outputs a 3000Hz pulse signal, which is half 6000Hz at maximum, the pulse cycle is "1/3000 ═ 333 μ s". The flow meter is generally a pulse signal generating device that generates pulses slower than the encoder.

When attempting to perform timing adjustment with high accuracy only based on the target value without using the timing adjustment value Ta, a flow meter having a high resolution as the encoder is required, which means that the acquisition cost of the flow meter increases.

(update of timing adjustment value Ta)

Fig. 9 is a diagram showing an outline of a method of updating the timing adjustment value Ta in the mounting application. The timing calculation unit 220 of the PLC20 performs statistical processing of the feedback values regarding the comparison matching output performed by the counter unit 10, for example, calculates an average value of a plurality of feedback values. The feedback value relating to the comparison and matching output from the counter unit 10 is a value indicating the "actual state of the workpiece 60 and the like" achieved by the actuator 40 that has received the comparison and matching output from the counter unit 10, and an example thereof is an assembly position described below.

When determining that the statistic value (for example, the average value) related to the feedback value has changed, the timing calculation unit 220 adjusts the timing adjustment value Ta, that is, updates the timing adjustment value Ta so as to eliminate the difference between the statistic value related to the feedback value and the reference value. The reference value is a value indicating a "predetermined ideal state of the workpiece 60 or the like" to be realized by the actuator 40 that has received the comparison and matching output from the counter unit 10, and is, for example, a predetermined ideal mounting position.

The timing calculation unit 220 records, for example, position data (data indicating the mounting position) as a feedback value at all times, and performs statistical tests such as t-test using a reference value for an average value of the feedback values at fixed time intervals. When it is determined by the statistical test that "the average value of the feedback values has significantly changed from the normal time", the timing calculation section 220 performs updating of the timing adjustment value Ta so as to cancel the change (difference from the reference value) in the average value of the feedback values.

Fig. 9 (a) is a diagram illustrating "mounting position x of workpiece 60" as a feedback value in a mounting application. The mounting position x indicates a position of the workpiece 60 on which the mounting member 70 is mounted in the local coordinate system of fig. 9 (a), in other words, indicates a mounting position of the mounting member 70 in the workpiece 60. In fig. 9, when the workpiece 60 is loaded by the conveyor and moved at a constant speed from the left side to the right side of the paper surface, the mounting position x indicates the following position. That is, the mounting position x indicates the mounting position of the mounting member 70 in the workpiece 60 in relation to the moving direction of the conveyor.

Fig. 9 (B) shows the statistical distribution relating to the reference value, and when "the feedback value (i.e., the mounting position x)" in which the average value matches the reference value is expressed as "the feedback value at the normal time", the statistical distribution relating to the feedback value at the normal time is shown. In the "statistical distribution relating to the feedback value (i.e., the reference value) in the normal state" shown in fig. 9 (B), the horizontal axis represents the average value of the mounting positions x, and the vertical axis represents the probability density. The timing calculation unit 220 obtains "statistical distribution regarding feedback values at normal times" illustrated in fig. 9 (B) in advance using teaching (teach) or the like, for example. The "statistical distribution relating to the feedback value at normal time (i.e., the reference value)" shown in fig. 9 (B) is indicated by a broken line in fig. 9 (C).

As shown in fig. 9 (C), the timing calculation unit 220 determines whether or not the feedback value deviates from the reference value (i.e., the "feedback value at normal time") by a predetermined magnitude or more by a statistical test such as a t-test. When determining that the feedback value deviates from the reference value by a predetermined magnitude or more, the timing calculation unit 220 changes (updates) the timing adjustment value Ta so as to eliminate the deviation therebetween.

For example, the timing calculation unit 220 determines that an abnormality occurs (abnormality occurs) when the deviation (difference) between the average value of the feedback values and the reference value is equal to or greater than a predetermined value. Then, the timing calculation unit 220 that determines that an abnormality has occurred adjusts the timing adjustment value Ta to correct the deviation.

In the example shown in fig. 9C, the average value of the feedback values shown by the solid line is shifted to the right of the drawing sheet by a predetermined amount or more from the reference value shown by the broken line (average value of the feedback values in the normal state), that is, the mounting position is shifted to the right of the drawing sheet from the ideal mounting position. This means that: at the time of assembly (the time of mounting the assembly member 70), the workpiece 60 is displaced to the left side of the drawing than the "position of the workpiece 60 during assembly" in the normal state illustrated in fig. 9 (B).

Therefore, the timing calculation unit 220 increases the value of the timing adjustment value Ta so as to shift the average value of the feedback values to the right side of the paper surface, that is, so as to shift the average value of the positions of the workpieces 60 at the time point of mounting the mounting members 70 to the right side of the paper surface. Since the workpiece 60 moves at a constant speed from the left side of the paper surface to the right side of the paper surface, the time point of mounting the mounting member 70 to the workpiece 60 is delayed by the amount of increase of the value of the timing adjustment value Ta, and the position of the workpiece 60 at the time point of mounting is moved to the right side of the paper surface.

The control system 1 can update the timing adjustment value Ta to an appropriate value by reflecting the difference between the reference value and the feedback value on the timing adjustment value Ta, and thus can realize highly accurate control using the updated timing adjustment value Ta.

(example of obtaining feedback value (1) regarding mounting position)

Fig. 10 is a diagram showing a specific example of a method for detecting the mounting position x in relation to the mounting application. The state detection device detects an actual state (for example, the mounting position x) of the workpiece 60 or the like realized by the actuator 40 that has received the comparison matching output from the counter unit 10, and transmits a detection result to the PLC20 as a feedback value relating to the comparison matching output.

Fig. 10 (a) shows an example in which: the actual state of the workpiece 60 (particularly, the mounting position x) at the time point when the mounting member 70 is mounted is detected as a feedback value relating to the comparison coincidence output using the photographing device 50 (camera) as the state detecting means. As shown in fig. 10 a, the position (mounting position x) of the workpiece 60 at the time when the mounting member 70 is mounted by the actuator 40 that has received the comparison matching output is specified in the captured image captured by the imaging device 50.

In the captured image, "mounting position x" indicates a position of the workpiece 60 on which the mounting member 70 is mounted in the local coordinate system of fig. 10 (a), in other words, indicates a mounting position of the mounting member 70 in the workpiece 60. In fig. 10, when the workpiece 60 is loaded by the conveyor and moved at a constant speed from the left side of the drawing to the right side of the drawing, the mounting position x indicates the following position. That is, the mounting position x indicates the mounting position of the mounting member 70 in the workpiece 60 in relation to the moving direction of the conveyor. The timing calculation section 220 of the PLC20 specifies the state (for example, the mounting position x) of the workpiece 60 or the like at the time point when the mounting member 70 is mounted as a feedback value relating to the comparison matching output, using the captured image acquired from the imaging device 50 at every control cycle.

Fig. 10 (B) shows an example in which: the actual state of the workpiece 60 (particularly, the mounting position x) at the time point when the mounting member 70 is mounted is detected as a feedback value relating to the comparison matching output using the displacement sensor 51 as a state detecting means. In fig. 10 (B), "the position of the part (the mounting member 70)" indicates the measurement distance, that is, "the position of the workpiece 60 at the time point when the mounting member 70 is attached (i.e., the mounting position x)".

As shown in fig. 10 (B), the displacement sensor 51 detects the measured distance at the time point when the mounting member 70 is mounted by the actuator 40 that has received the comparison matching output, and transmits the detected measured distance as a feedback value to the PLC 20. The timing calculation unit 220 of the PLC20 specifies the state (for example, the mounting position x) of the workpiece 60 and the like at the time point when the mounting member 70 is mounted as a feedback value relating to the comparison matching output, using the measurement distance acquired from the displacement sensor 51 at each control cycle.

(example of obtaining feedback value (1) regarding filling amount)

Fig. 11 is a diagram showing a specific example of a method for detecting an actual filling amount in relation to a liquid filling application. The state detection device detects an actual state (for example, a weight/an accumulated amount) of the workpiece 60 or the like realized by the actuator 40 that has received the comparison matching output from the counter unit 10, and transmits a detection result to the PLC20 as a feedback value relating to the comparison matching output.

Fig. 11 (a) shows an example in which the actual weight/accumulated amount of liquid that has been filled into the workpiece 61 at the point in time when the valve (actuator) stops filling is detected as a feedback value relating to the comparison coincidence output using the load cell 52 as the state detection means.

As shown in fig. 11 (a), the load cell 52 detects the weight/cumulative amount of the workpiece 61 at the time point when the liquid filling is stopped by the valve that has received the comparison and matching output, and transmits a voltage value indicating the detected weight/cumulative amount as a feedback value to the PLC 20. The timing calculation section 220 of the PLC20 uses the voltage values acquired from the load cell 52 every control cycle as feedback values relating to the comparison coincidence output to determine the state (e.g., weight/cumulative amount) of the workpiece 61 at the point in time when liquid filling is stopped.

Fig. 11 (B) shows an example in which the distance from the time point when the valve (actuator) stops filling to the liquid surface of the liquid that has been filled into the workpiece 61 is detected as a feedback value relating to the comparison matching output using the distance measuring device 53 as the state detecting device. In fig. 11 (B), "distance to the liquid surface" indicates "filling amount of liquid that has been filled into the workpiece 61 at the time point when the valve stops filling".

As shown in fig. 11 (B), the distance measuring device 53 detects the distance to the liquid surface of the liquid filled into the workpiece 61 at the time point when the filling of the valve receiving the comparatively uniform output is stopped, using a laser or the like. The distance measuring device 53 transmits the detected measured distance to the PLC20 as a feedback value. The timing calculation unit 220 of the PLC20 uses the measured distance acquired from the distance measuring device 53 at every control cycle as a feedback value relating to the comparison match output to specify the state of the workpiece 61 or the like (for example, the amount of filling into the workpiece 61) at the time point when the valve stops filling.

Modification example 4

(control device)

The PLC20 is an example of the control device that transmits the target value and the timing adjustment value Ta to the counter unit 10 at regular communication cycles. However, the control device that transmits the target value and the timing adjustment value Ta to the counter unit 10 does not necessarily have to be a PLC. The control device that transmits the target value and the timing adjustment value Ta to the counter unit 10 may be an Industrial Personal Computer (IPC) or the like.

(with respect to pulse signals)

In the description so far, an example in which the period Tp of the pulse signal is fixed in principle is described. For example, the description has been given assuming that the amount of movement (moving speed) per unit time of the workpiece (conveyor) is fixed, and the amount of filling (filling speed) per unit time of the liquid into the workpiece is fixed.

However, the period Tp of the pulse signal may be predictable for the counter unit 10, and it is not essential for the counter unit 10 that the period Tp of the pulse signal is fixed. The counter unit 10 can set the target value and the timing adjustment value Ta so long as the period Tp of the pulse signal can be predicted, and can generate a target value match (match between the actual measurement value and the target value) at a timing that is equal to or longer than the response time from the operation completion timing of the actuator.

In the control system 1, the timing adjustment value Ta may be set to a value that does not depend on (is independent of) the period Tp of the pulse signal. The counter unit 10 uses the timing adjustment value Ta, sets a time that does not depend on the period Tp of the pulse signal as a standby time, and performs a predetermined output to the actuator at a time point when the standby time has elapsed from a time point when it is determined that the actual measurement value matches the target value.

[ implementation by software ]

The functional blocks of the counter Unit 10 and the PLC20 (specifically, the communication Unit 110, the setting Unit 120, the measurement Unit 130, the determination Unit 140, the output Unit 150, and the timing calculation Unit 220) may be implemented by a logic circuit (hardware) formed on an integrated circuit (IC chip) or the like, or may be implemented by software using a Central Processing Unit (CPU).

In the latter case, each of the counter unit 10 and the PLC20 includes a CPU that executes instructions of a program that is software for realizing each function, a Read Only Memory (ROM) or a storage device (these are referred to as "recording media") in which the program and various data are recorded so as to be readable by a computer (or CPU), a Random Access Memory (RAM) in which the program is developed, and the like. And, the object of the present invention is achieved by reading and executing the program from the recording medium by a computer (or CPU). As the recording medium, "a tangible medium that is not temporary" may be used, and for example, a tape (tape), a disk (disk), a card (card), a semiconductor memory, a programmable logic circuit, or the like may be used. Further, the program may be supplied to the computer via an arbitrary transmission medium (a communication network, a broadcast wave, or the like) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave, the data signal embodying the program by electronic transmission.

(matters attached to notes)

The counter unit of an embodiment of the present invention includes: a measuring unit for counting the number of pulses of the pulse signal to measure an actual measurement value; a comparison unit configured to determine whether the actual measurement value measured by the measurement unit matches a target value; and an output unit configured to output the actual measurement value to an actuator when the comparison unit determines that the actual measurement value matches the target value, wherein the output unit includes an output delay unit configured to adjust timing of the output to a point in time that is independent of a period of the pulse signal and is indicated by a timing adjustment value after a point in time when the comparison unit determines that the actual measurement value matches the target value has elapsed.

According to the above configuration, the counter unit receives the pulse signal as an input from a pulse signal generating device, such as an encoder or a flow meter, which generates the pulse signal according to a detected amount, and measures the actual measurement value from the received pulse signal. When the counter unit determines that the actual measurement value matches the target value, the counter unit outputs the pulse signal at a time point when a time period independent of the period Tp of the pulse signal indicated by the timing adjustment value has elapsed from the time point at which the actual measurement value matches the target value. Hereinafter, the timing adjustment value is also referred to as "timing adjustment value Ta".

Conventionally, there is known a technique of: the timing of the output is adjusted by increasing or decreasing a target value for a counter unit that executes the output when it is determined that an actual measurement value measured by counting the number of pulses of the pulse signal matches the target value.

Here, the target value can be increased or decreased only by an integral multiple of the actual measurement value corresponding to the "period of the pulse signal (pulse period Tp)". Therefore, in the conventional counter unit that adjusts the output timing only according to the target value, the resolution related to the adjustment of the output timing is limited to the pulse period Tp. In particular, when the pulse period Tp is long, the conventional counter unit cannot finely adjust the output timing, and the timing error becomes large. Further, since the response time is fixed regardless of the pulse period Tp, when the pulse period Tp changes, the conventional counter unit cannot maintain the output timing unless the target value is increased or decreased in accordance with the changed pulse period Tp, and thus the user convenience is low.

In such a conventional counter unit, the counter unit adjusts the timing of the output using the timing adjustment value Ta indicating a time (standby time) independent of the period Tp of the pulse signal, in addition to the target value. That is, the counter unit adjusts the timing of the output to a point in time that is independent of the period Tp of the pulse signal and is indicated by the timing adjustment value Ta after the point in time at which it is determined that the actual measurement value matches the target value.

Therefore, the counter unit has the following effects: the timing of the output can be adjusted by using the timing adjustment value Ta independently of the period Tp of the pulse signal, that is, independently of the period Tp of the pulse signal. In particular, since the time indicated by the timing adjustment value Ta is independent of the period Tp of the pulse signal, the counter section can finely adjust the timing of the output even when the pulse period Tp is long. In addition, even when the pulse period Tp is changed, the counter unit can easily adjust the timing of the output by changing the value of the timing adjustment value Ta by the amount of change in the pulse period Tp, and thus the user convenience is high.

In the counter unit according to an embodiment of the present invention, the output unit may include a hardware-based logic circuit, and the time indicated by the timing adjustment value may be an integral multiple of a clock of the logic circuit.

According to the above configuration, in the counter unit, the output unit includes a hardware-based logic circuit. For example, the output unit may be implemented using at least one of a Field Programmable Gate Array (FPGA), a Complex Programmable Logic Device (CPLD), and an Application Specific Integrated Circuit (ASIC). In the counter unit, the timing adjustment value Ta is an integer multiple of the clock of the logic circuit.

Here, by implementing the output unit by a logic circuit based on hardware, the delay amount can be made smaller than in the case where the output unit is implemented by software. That is, by implementing the output unit by a logic circuit based on hardware, it is possible to set a smaller value for the time (standby time) indicated by the timing adjustment value Ta than in the case where the output unit is implemented by software. Further, by implementing the output unit by a logic circuit based on hardware, it is possible to suppress variation in delay as compared with a case where the output unit is implemented by software.

Therefore, the counter unit has the following effects: when it is determined that the actual measurement value matches the target value, the output to the actuator can be performed with a shorter standby time than when the output unit is implemented by software. Moreover, the counter unit has the following effects: the variation in delay can be suppressed as compared with the case where the output unit is implemented by software.

The counter unit according to an embodiment of the present invention may further include a communication unit that receives the target value and the timing adjustment value from a control device that performs input/output processing of on/off data at a predetermined control cycle.

According to this configuration, the counter unit receives the target value and the timing adjustment value Ta from the control device, and adjusts the timing of the output using the received target value and the timing adjustment value Ta.

Here, a communication method of the counter unit and the control device is not particularly limited. The counter unit and the control device may be communicably connected to each other via a field network, for example, and the counter unit receives the target value and the timing adjustment value Ta from the control device via the field network. Further, the counter unit may be integrally formed with the control device, that is, may be communicably connected to the control device via an internal bus. In this case, the counter unit may receive the target value and the timing adjustment value Ta from the control device via an internal bus.

For example, the counter unit repeatedly receives the target value and the timing adjustment value Ta from the control device every the control cycle, and adjusts the timing of the output using the received target value and the received timing adjustment value Ta.

Therefore, the counter unit has the following effects: the actual measurement value measured by the own device is compared with the target value received from the control device, and the timing of the output can be adjusted using the timing adjustment value Ta received from the control device. That is, the user can adjust the timing of the output using the target value and the timing adjustment value Ta that the control device transmits to the counter unit (for example, periodically).

In the counter unit according to an embodiment of the present invention, the timing adjustment value may be updated using a feedback value indicating an actual state of the workpiece realized by the actuator that receives the output from the counter unit.

According to the structure, the counter unit has the following effects: the timing of the output can be adjusted with high accuracy by the timing adjustment value Ta updated to an appropriate value using a feedback value relating to the output to the actuator.

In the counter unit according to an embodiment of the present invention, the timing adjustment value may be updated using a difference between a reference value indicating a predetermined ideal state of the workpiece to be realized by the actuator that has received the output and a value calculated by performing statistical processing on a plurality of the feedback values.

According to the above configuration, the counter unit adjusts the timing of the output by using the timing adjustment value Ta updated to an appropriate value by using a difference between the reference value and a value calculated by statistically processing the plurality of feedback values.

Here, by updating the timing adjustment value Ta using a value calculated by statistically processing a plurality of the feedback values, even when the feedback values temporarily exhibit an abnormal value, the influence of such an abnormal value on the timing adjustment value Ta can be suppressed.

Therefore, the counter unit has the following effects: even when the feedback value temporarily exhibits an abnormal value, the timing of the output can be adjusted with high accuracy by using the timing adjustment value Ta updated to an appropriate value while suppressing the influence from such an abnormal value.

The control device according to an embodiment of the present invention may also execute input/output processing of enable/disable data at a prescribed control cycle, and includes: and an updating unit configured to update the timing adjustment value by using, as a feedback value relating to the output, a value indicating an actual state of the workpiece realized by the actuator that has received the output from the counter unit, and to transmit the timing adjustment value and the target value updated by the updating unit to the counter unit.

According to this configuration, the control device updates the timing adjustment value Ta to an appropriate value using the feedback value, and transmits the updated timing adjustment value Ta and the target value to the counter unit.

Therefore, the control device has the following effects: by transmitting the timing adjustment value Ta updated to an appropriate value and the target value, the timing of the output can be adjusted to an appropriate time point independent of the period Tp of the pulse signal.

Here, the control device may acquire the feedback value from a state detection device implemented using, for example, an imaging device (camera), various sensors (specifically, a displacement sensor, a load cell, a distance measurement device using laser light, or the like), or the like. Furthermore, the control device may be integrally formed with the counter unit.

In the control device according to an embodiment of the present invention, the update unit may update the timing adjustment value using a difference between a reference value indicating a predetermined ideal state of the workpiece to be realized by the actuator that has received the output and a value calculated by performing statistical processing on a plurality of the feedback values.

According to this configuration, the control device updates the timing adjustment value Ta for adjusting the timing of the output to an appropriate value using the difference between the reference value and the value calculated by statistically processing the plurality of feedback values.

Here, by updating the timing adjustment value Ta using a value calculated by statistically processing a plurality of the feedback values, even when the feedback values temporarily exhibit an abnormal value, the influence of such an abnormal value on the timing adjustment value Ta can be suppressed.

Therefore, the control device has the following effects: even when the feedback value temporarily exhibits an abnormal value, the timing adjustment value Ta can be updated to an appropriate value in which the influence from such an abnormal value is suppressed.

The control system of an embodiment of the present invention may also include: the counter unit; the control device; and a state detection device that detects an actual state of the workpiece that is achieved by the actuator that receives the output from the counter unit, and transmits a value indicating the detected actual state of the workpiece to the control device as the feedback value.

According to the above configuration, the control system includes the counter unit, the control device, and the state detection device, and the counter unit adjusts the timing of the output using the timing adjustment value updated by the update unit.

The control system has the following effects: the timing adjustment value Ta can be updated to an appropriate value using the feedback value detected by the state detection means. Moreover, the control system has the following effects: the timing of the output can be adjusted to a timing independent of the period Tp of the pulse signal using the timing adjustment value Ta that has been updated to an appropriate value.

In particular, since the time indicated by the timing adjustment value Ta is independent of the period Tp of the pulse signal, the control system can finely adjust the timing of the output even when the pulse period Tp is long. In addition, even when the pulse period Tp changes, the control system can easily adjust the timing of the output by changing the value of the timing adjustment value Ta by the amount of change in the pulse period Tp, and thus the user convenience is high.

Here, the state detection device can be realized using, for example, an imaging device (camera), various sensors (specifically, a displacement sensor, a load cell, a distance measurement device using a laser, or the like), or the like. Also, the counter unit and the control device may be integrally formed.

In the control system according to an embodiment of the present invention, the control device may update the timing adjustment value using a difference between a reference value indicating a predetermined ideal state of the workpiece to be realized by the actuator that has received the output and a value calculated by performing statistical processing on a plurality of the feedback values.

According to this configuration, the control system adjusts the timing of the output using the timing adjustment value Ta updated by the difference between the reference value and the value calculated by statistically processing the plurality of feedback values.

Here, by updating the timing adjustment value Ta using a value calculated by statistically processing a plurality of the feedback values, even when the feedback values temporarily exhibit an abnormal value, the influence of such an abnormal value on the timing adjustment value Ta can be suppressed.

Therefore, the control system has the following effects: even when the feedback value temporarily exhibits an abnormal value, the timing of the output can be adjusted with high accuracy by using the timing adjustment value Ta updated to an appropriate value while suppressing the influence from such an abnormal value.

The control method of the counter unit of an embodiment of the present invention includes: a measuring step of counting the number of pulses of the pulse signal to measure an actual measurement value; a comparison step of determining whether the measured value measured in the measurement step matches a target value; and an output step of executing an output to an actuator when it is determined in the comparison step that the actual measurement value matches the target value, the output step including an output delay step of adjusting a timing of the output to a time point that is independent of a cycle of the pulse signal and that is indicated by a timing adjustment value from a time point at which it is determined in the comparison step that the actual measurement value matches the target value.

According to the above configuration, in the control method, the pulse signal is received as an input from a pulse signal generating device that generates the pulse signal in accordance with a detected amount, such as an encoder or a flow meter, and the actual measurement value is measured based on the received pulse signal. In the control method, when it is determined that the actual measurement value matches the target value, the output is performed at a time point when a time period independent of the period Tp of the pulse signal indicated by the timing adjustment value has elapsed from the time point at which the actual measurement value matches the target value. Hereinafter, the timing adjustment value is also referred to as "timing adjustment value Ta".

Conventionally, there is known a technique of: the timing of the output is adjusted by increasing or decreasing a target value for a counter unit that executes the output when it is determined that an actual measurement value measured by counting the number of pulses of the pulse signal matches the target value.

Here, the target value can be increased or decreased only by an integral multiple of the actual measurement value corresponding to the "period of the pulse signal (pulse period Tp)". Therefore, in the conventional counter unit that adjusts the output timing only according to the target value, the resolution related to the adjustment of the output timing is limited to the pulse period Tp. In particular, when the pulse period Tp is long, the conventional counter unit cannot finely adjust the output timing, and the timing error becomes large. Further, since the response time is fixed regardless of the pulse period Tp, when the pulse period Tp changes, the conventional counter unit cannot maintain the output timing unless the target value is increased or decreased in accordance with the changed pulse period Tp, and thus the user convenience is low.

In the conventional counter unit, the timing of the output is adjusted by using the timing adjustment value Ta indicating a time (standby time) independent of the period Tp of the pulse signal, in addition to the target value. That is, in the control method, the timing of the output is adjusted to a point in time that is independent of the period Tp of the pulse signal and is indicated by the timing adjustment value Ta after the point in time at which it is determined that the actual measurement value matches the target value.

Therefore, the control method has the following effects: the timing of the output can be adjusted by using the timing adjustment value Ta independently of the period Tp of the pulse signal, that is, independently of the period Tp of the pulse signal. In particular, since the time indicated by the timing adjustment value Ta is independent of the period Tp of the pulse signal, the control method can finely adjust the timing of the output even when the pulse period Tp is long. In the above control method, even when the pulse period Tp is changed, the timing of the output can be easily adjusted by changing the value of the timing adjustment value Ta by the amount of change in the pulse period Tp, and thus the user convenience is high.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical components disclosed in different embodiments are also included in the technical scope of the present invention.

Description of the symbols

1: control system

10: counter unit

20: PLC (control device)

40: actuator

50: shooting device (State detecting device)

51: displacement pickup (State detecting device)

52: force transducer (State detecting device)

53: distance measuring device (State detecting device)

60: workpiece

61: workpiece

110: communication unit

130: measuring part

140: determination unit (comparison unit)

150: output unit

160: output delay unit

220: opportunity calculating part (updating part)

Ta: timing adjustment value

Tp: pulse period (period of pulse signal)