Conveyor system, method of operating a conveyor system and flow device for use in such a conveyor system
阅读说明：本技术 输送机系统、操作输送机系统的方法以及在这种输送机系统中使用的流动装置 (Conveyor system, method of operating a conveyor system and flow device for use in such a conveyor system ) 是由 马茨·瓦伦 罗兰·伦丁 安德斯·阿克斯曼 于 2018-06-20 设计创作，主要内容包括：本文档披露了一种输送机系统，该输送机系统包括多个工件载体(WPC)，每个工件载体适于在运输期间支撑至少一个工件(WP)；输送机(10，10a，10b，10c，d)，该输送机适于运输工件载体(WPC)；至少一个流动装置(3，4，5，6)，用于控制这些工件载体(WPC)之一相对于该输送机(10，10a，10b，10c，10d)的运动，该流动装置(3，4，6)包括本地控制器(30，40)、至少一个工件载体传感器和至少一个致动器；以及中央控制器(100)，该中央控制器与该流动装置进行数据通信并具有存储器，该存储器包含流动计划，该流动计划包括描述工件在该输送机系统中的预期流动的数据。该文献还披露了一种用于操作输送机系统、在这种输送机系统中使用的止动装置和道岔装置的方法。(This document discloses a conveyor system comprising a plurality of Work Piece Carriers (WPC), each work piece carrier being adapted to support at least one Work Piece (WP) during transport; a conveyor (10, 10a, 10b, 10c, d) adapted to transport a Work Piece Carrier (WPC); at least one flow device (3, 4, 5, 6) for controlling the movement of one of the Work Piece Carriers (WPC) relative to the conveyor (10, 10a, 10b, 10c, 10d), the flow device (3, 4, 6) comprising a local controller (30, 40), at least one work piece carrier sensor and at least one actuator; and a central controller (100) in data communication with the flow device and having a memory containing a flow plan including data describing an expected flow of workpieces in the conveyor system. This document also discloses a method for operating a conveyor system, a stop device and a switch device for use in such a conveyor system.)
1. A conveyor system comprising:
a plurality of work-piece carriers (WPC), each work-piece carrier being adapted to support at least one work-piece (WP) during transport;
a conveyor (10, 10a, 10b, 10c, 10d) adapted to transport the Work Piece Carriers (WPC),
at least one flow device (3, 4, 5, 6) for controlling the movement of one of the Work Piece Carriers (WPC) relative to the conveyor (10, 10a, 10b, 10c, 10d), the flow device (3, 4, 5, 6) comprising a local controller (30, 40), at least one work piece carrier sensor and at least one actuator, and
a central controller (100) in data communication with the flow device and having a memory containing a flow plan including data describing expected flow of workpieces in the conveyor system,
wherein the local controller is configured to:
the sensor signal is received via a signal interface,
converts the sensor signal into signal data having a predetermined data format,
the sensor data is transmitted to the central controller via a data interface,
receiving command data from the central controller via the data interface, and
an actuator control signal is provided to the actuator based on the command data.
2. A conveyor system as in claim 1 wherein the local controller is configured to determine whether to override the steps of transmitting the sensor data to and receiving the command data from the central controller based on the sensor signal and/or the sensor data and then autonomously generate the command data.
3. A conveyor system as in claim 2 wherein the local controller is configured to autonomously provide the command data when it determines that the workpiece carrier (WPC) is not carrying a valid workpiece.
4. A conveyor system as in any of claims 1-3 wherein the local controller is configured to receive the command data in response to the transmission of the sensor data.
5. A conveyor system as in any of claims 1-4 wherein the central controller is configured to:
receiving the sensor data from the local controller,
determining an action to be taken by the flow device based on the flow plan and the sensor data,
providing command data corresponding to the action, and
the command data is sent to the local controller.
6. The system of any one of claims 1 to 5, wherein the local controller is configured to transmit sensor data to the central controller only when triggered by a change in the sensor data or by the command data.
7. The conveyor system of any one of claims 1 to 6, wherein the flow device is a stop device (3) for stopping the movement of one of the Work Piece Carriers (WPC) relative to the conveyor (10, 10a, 10b, 10c, 10d),
wherein the work carrier sensor comprises a stop control detection device (31, 32, 33) configured to detect the presence of a work carrier (WPC) reaching the detection device (31, 32, 33) and/or to detect the presence of a work on the work carrier (WPC), and
wherein the actuator comprises a stop control actuator (35) configured to stop the movement of the Work Piece Carrier (WPC) relative to the conveyor (10, 10a, 10b, 10c, 10d),
wherein the stopping means further comprises a tag reader and/or writer (34); and is
Wherein the local controller is a stop local controller (30) operatively connected to the stop control detection means (31, 32, 33), the stop control actuation means (35) and the tag reader/writer (34) to receive detection signals from the stop control detection means (31, 32, 33), to transmit control signals to the stop control actuation means (35) and to receive/transmit tag data from/to the tag reader/writer (34); and is
Wherein the immobilization local controller (30) is configured to:
receiving the sensor signal from the stop control detection means (31, 32, 33),
receives tag data from the tag reader/writer,
transmitting sensor data corresponding to the sensor signal and the tag data to the central controller (100) in the form of a stop event message,
receiving a stop control command from the central controller (100), said command comprising an indication to release the work piece carrier and/or an indication of data to be written to the tag, and
controlling the actuator to release the workpiece carrier.
8. A conveyor system as in claim 7 wherein the tag data comprises ID data and/or address data and wherein the stop control command comprises an indication to write the modified ID data and/or tag data.
9. The conveyor system of any one of claims 1 to 6, wherein said conveyor is configured to provide at least one Y-intersection having an input conveyor line and a greater number of output conveyor lines, and wherein the flow device is a switch device (4) for selectively transferring input workpiece carriers (WPC) to one of the output conveyor lines,
wherein the actuator includes a switch actuating device (41) configured to selectively transfer the workpiece carrier to the one of the output conveyor lines,
wherein the workpiece carrier sensor includes a switch zone state detector (42a, 42b) configured to detect the presence of a workpiece carrier on a downstream side of the switch actuating device (41), and
wherein the local controller comprises a switch local controller (40) operatively connected to the switch actuating device (41) and the switch zone state detector (42a, 42b) to send control signals to the switch actuating device (41) and to receive detection signals from the zone state detector (42a, 42 b); and is
Wherein the local controller is configured to:
receiving switch control commands from the central controller (100),
receives a signal from the switch zone state detector, and
and sending a turnout reply message indicating the state of the turnout area and the position of the turnout.
10. A conveyor system as in claim 9 wherein the central controller is configured to:
determining to which output line the workpiece carrier is to be directed based on the flow plan,
sending the switch control command to the switch device to indicate the desired switch position, an
The switch reply message is received.
11. A conveyor system as in claim 9 or 10 wherein the local controller is configured to determine whether to override said receiving the switch control command from the central controller, said receiving a signal from the switch zone state detector, and said sending a switch reply message based on the sensor signal or the sensor data, and to autonomously control the switch actuating device (41) to assume a desired position.
12. A method of operating a conveyor system, the conveyor system comprising:
a plurality of work-piece carriers (WPC), each work-piece carrier being adapted to support at least one work-piece (WP) during transport;
at least one conveyor (10, 10a, 10b, 10c, 10d) adapted to transport the Work Piece Carriers (WPC);
at least one flow device for controlling the movement of the Work Piece Carriers (WPC) relative to the conveyor (10, 10a, 10b, 10c, 10d), the flow device comprising a local controller, at least one work piece carrier sensor and at least one actuator, and
a central controller (100) in data communication with the flow device and having a memory containing a flow plan including data describing expected flow of workpieces in the conveyor system,
the method comprises the following steps:
receiving a sensor signal at the local controller via a signal interface,
converting the sensor signals to a data format to form a sensor,
the sensor data is transmitted to the central controller via a data interface,
command data is received from the central controller via the data interface,
providing an actuator control signal in response to the command data, an
The actuator control signal is provided to the actuator.
13. The method of claim 12, wherein the command data is received by the local controller in response to the transmission of the sensor data to the central controller.
14. The method of claim 12 or 13, further comprising: based on the sensor signal and/or the sensor data, it is determined whether to override the steps of transmitting the sensor data to the central controller and receiving the command data from the central controller, and then autonomously generate the command data.
15. A stop device (3) for use in a conveyor system configured to transport a plurality of work piece carriers by means of a conveyor, the device being configured for stopping the movement of one of the Work Piece Carriers (WPC) relative to the conveyor (10, 10a, 10b, 10c, 10d), the stop device (3) comprising:
a stopping control detection device (31, 32, 33) configured to detect the presence of a work carrier (WPC) reaching the detection device (31, 32, 33) and/or to detect the presence of a work on the work carrier (WPC), and
a stop control actuator (35) configured to stop movement of the work carrier (WPC) relative to the conveyor (10, 10a, 10b, 10c, 10d),
a tag reader and/or writer (34); and
a stop local controller (30) operatively connected to the stop control detection means (31, 32, 33), the stop actuation means (35) and the tag reader/writer (34) to receive detection signals from the stop control detection means (31, 32, 33), to transmit control signals to the stop control actuation means (35) and to receive/transmit tag data from/to the tag reader/writer (34);
wherein the immobilization local controller (30) is configured to:
receiving the sensor signal from the stop control detection means (31, 32, 33),
controlling the stop control actuator to stop the workpiece carrier in response to the sensor signal,
receives tag data from the tag reader/writer,
transmitting sensor data corresponding to the sensor signal and the tag data to a central controller (100) in the form of a stop event message,
receiving a stop control command from the central controller (100), said command comprising an indication to release the work piece carrier and/or an indication of data to be written to the tag, and
and controlling the stop control actuator to release the workpiece carrier.
16. The immobilization device of claim 15, wherein the immobilization local controller is configured to receive the immobilization control command in response to said transmission of the sensor data to the central controller.
17. An immobilization device as claimed in claim 15 or 16, wherein the tag data comprises ID data and/or address data, and wherein the immobilization control command comprises an indication for writing modified ID data and/or tag data.
18. The retaining device of any one of claims 15-17, wherein the retaining device further comprises:
the work piece carrier reaches a detector (31),
a work carrier position detector (32), and/or
A workpiece presence detector (33),
wherein the stop event message further comprises:
data indicating that the workpiece carrier reaches the stop flow controller,
data indicating whether the workpiece carrier is in a predetermined stop position, and/or
Data indicating whether a workpiece is present.
19. The immobilization device of any of claims 15 to 18, wherein the immobilization device further comprises at least one zone status detector (36) configured to detect whether a work carrier (WPC) is present on a downstream side of the immobilization control actuation device (35), and wherein the stop event message further comprises an indication whether the zone is clear.
20. The immobilization device of any of claims 15-19, wherein the local controller is configured to determine whether to override the steps of transmitting the sensor data to the central controller and receiving the command data from the central controller based on the sensor signal, the tag data, and/or the sensor data, and then autonomously generate the immobilization control command.
21. A switch arrangement (4) for use in a conveyor system configured to transport a plurality of workpiece carriers by means of a conveyor and including at least one Y-intersection having an input conveyor line and a greater number of output conveyor lines, the switch arrangement being configured for selectively transferring one of the workpiece carriers to one of the output conveyors, the switch arrangement comprising:
a switch actuating device (41) configured to selectively transfer a workpiece carrier from the conveyor,
a switch zone state detector (42a, 42b) configured to detect the presence of a workpiece carrier on a downstream side of the switch actuator (41), an
A switch local controller (40) operatively connected to the switch actuating device (41) and the switch zone state detector (42a, 42b) to send control signals to the switch actuating device (41) and to receive detection signals from the zone state detector (42a, 42 b);
wherein the local controller is configured to:
receiving switch control commands from a central controller (100) via a data interface,
receiving a detection signal from the switch area state detector, and
switch reply messages indicating switch zone status and switch location are sent to the central controller (100) via the data interface.
22. The switch apparatus as claimed in claim 21, wherein the switch local controller is configured to send the switch reply message in response to having received the switch control command.
23. A conveyor system as in claim 21 or 22 wherein the switch local controller is configured to determine whether to override said receiving the switch control command from the central controller and said sending switch reply message based on the detection signal or tag data received from a tag reader and to autonomously control the switch actuating device (41) to assume a predetermined position.
24. A conveyor system comprising:
a plurality of work-piece carriers (WPC), each work-piece carrier being adapted to support at least one work-piece (WP) during transport;
a conveyor (10, 10a, 10b, 10c, 10d) adapted to transport the Work Piece Carriers (WPC),
at least one stop device according to any one of claims 16 to 20, configured to stop the movement of a workpiece carrier along the conveyor, and
a central controller (100) in data communication with the stopping device (3) and having a memory device containing a flow plan including data describing an expected flow of workpieces in the conveyor system,
wherein the central controller is configured to:
receiving the stop event message from the immobilizer,
based on the label data and the flow plan, it is determined whether to release the workpiece carrier, and
the immobilization control command is sent to the immobilization device.
25. A conveyor system as in claim 24 wherein the central controller is configured to determine whether to release a workpiece carrier and send the stop control command in response to receiving the stop event message.
26. The conveyor system of claim 24 or 25, further comprising:
at least one Y-shaped cross having an input feed line and a greater number of output feed lines,
at least one switch device as claimed in claim 21 or 22 associated with the Y-shaped cross,
wherein the central controller (100) is configured to:
generating the switch control command based on the flow plan, and
the switch control command is sent to the switch device,
the central controller is further configured to receive the switch reply message from the switch device (4) and also determine whether to release the workpiece carrier based on the switch position and/or switch zone status.
27. A conveyor system as in claim 26, wherein the switch device (4) is arranged downstream of the stop control actuating device (35), and wherein the central controller (100) is further configured to:
based on the label data and the flow plan, it is determined to which output line the workpiece carrier is to be directed, and
a switch control command is sent to the switch device (4) to indicate a desired switch position.
28. A conveyor system as claimed in claim 26 or 27, wherein the central controller (100) is further configured to receive switch reply messages from the switch device (4) indicating the current switch position and switch zone status, and to determine whether to release a workpiece carrier and/or to which output conveyor line to direct such released workpiece carrier also based on the switch position and/or switch zone status.
29. A production system comprising at least two stations selected from the group consisting of processing stations, additive manufacturing stations, surface treatment stations and assembly stations, the production system comprising a conveyor system configured to convey workpieces from one station to another as claimed in any one of claims 1 to 11 or 24 to 28.
Technical Field
The present disclosure relates to a conveyor system for moving workpieces between a set of stations.
The conveyor system is adapted to provide an automated production system, i.e., a system that transports workpieces between operating stations without manual intervention.
Background
Conveyor systems are used in many types of manufacturing industries to move workpieces between different types of operating stations.
Establishing such conveyor systems typically involves extensive programming; the control software needs to handle each sensor and each actuator and keep track of each workpiece and each operating station.
When changing manufacturing systems, it is often a very challenging task to install or remove the handling station and rebalance the system so that no unintended buffers are formed. This also involves modifying the control software, which typically involves a significant amount of labor.
Furthermore, wear and failure may cause the system to drift over time, causing a need for rebalancing, which in turn requires reprogramming of the control software.
In conveyor systems for automated production, it is known to receive all sensor data in a central controller and to issue commands from the central controller to actuators. Thus, all functions in the conveyor system are centrally controlled; each start, stop, track switch, data collection and data generation is directly controlled by the central controller.
Therefore, extensive wiring and programming is required to build such a conveyor system.
On the other hand, there is a need to reduce the cost for designing, building and configuring conveyor systems.
Disclosure of Invention
It is therefore a general object to provide an improved centrally controlled conveyor system, and in particular such a system which can be installed and maintained at lower cost and which is preferably more robust.
The invention is defined by the appended independent claims, wherein embodiments are set forth in the dependent claims, in the following description and in the drawings.
According to a first aspect, there is provided a conveyor system comprising a plurality of workpiece carriers, each workpiece carrier being adapted to support at least one workpiece during transport; a conveyor adapted to transport the workpiece carriers; at least one flow device for controlling movement of one of the workpiece carriers relative to the conveyor, the flow device comprising a local controller, at least one workpiece carrier sensor, and at least one actuator; and a central controller in data communication with the flow device and having a memory containing a flow plan including data describing an expected flow of workpieces in the conveyor system. The local controller is configured to receive a sensor signal via a signal interface, convert the sensor signal to signal data having a predetermined data format, transmit the sensor data to the central controller via a data interface, receive command data from the central controller via the data interface, and provide an actuator control signal to an actuator based on the command data.
A flow plan is a set of instructions describing one or more ways in which the conveyor system transports workpieces. The flow plan may be fixed in the sense that it can only be altered by operator intervention (optionally in conjunction with a closed conveyor system), or dynamic in the sense that it can be changed in response to events occurring in production. Such changes may be effected automatically, by a control system, or by operator intervention.
The local controller may be configured to determine whether to override the steps of transmitting the sensor data to the central controller and receiving the command data from the central controller based on the sensor signal and/or the sensor data, and then autonomously generate the command data.
Thus, if it decides to override, the local controller itself will generate and execute the command data without having to communicate with the central controller in advance. This may reduce the amount of information that needs to be communicated with the central controller.
The local controller may be configured to autonomously provide the command data when it determines that the workpiece carrier is not carrying a valid workpiece.
Thus, when a workpiece carrier is empty or a workpiece may be, for example, incorrectly positioned or otherwise malfunctioning, the local controller may make an autonomous decision to stop and/or pass the workpiece carrier. Instead, the workpiece carrier may be centrally controlled instead when it carries valid workpieces.
The local controller may be configured to receive the command data in response to the transmission of the sensor data.
This therefore implies that the conveyor system is run in real time, i.e. the central controller sends specific command data in response to the received specific sensor data. In other words, the central controller is triggered to make decisions and send command data only when sensor data is received. Thus, the command data is immediately provided by the central controller due to and in response to the sensor data received by the central controller. Typically, the command data will be received within 15 seconds, preferably within 10 seconds, 5 seconds, 1 second, or 0.5 seconds, after the local controller sends the sensor data.
This configuration of the conveyor system facilitates design, assembly, maintenance, and redesign of the conveyor system.
Since the local controller is configured to convert sensor data to signal data, one data format may be used for all communications between the local controller and the central controller.
Furthermore, since the signals to and from the actuators and sensors are provided by a local controller, there is no need to connect the sensors and actuators to a central controller.
The central controller may be configured to receive sensor data from the local controller, determine an action to be taken by the flow device based on the flow plan and the sensor data, provide command data corresponding to the action, and send the command data to the local controller.
Thus, the central controller can make real-time decisions based not only on sensor data but also on flow plans. Thus, the central controller will effectively decide the movement of the workpiece carrier, i.e. whether to stop, release or transfer the workpiece carrier, while the flow means only execute commands received from the central controller.
Thus, the command data may be selected from the group consisting of: a command to stop the workpiece carrier, a command to release the workpiece carrier, and a command to transfer the workpiece carrier (e.g., by causing a switch unit control arm to move the workpiece carrier to another conveyor section). Further, where a tag writer is included, the command data may also include an indication of the data to be written to the tag. Such data may also be provided in response to sensor data and/or in response to any tag data read from the tag and/or in response to further sensor data and/or based on a flow plan.
The local controller may be configured to transmit the sensor data to the central controller only in reply to a change in the sensor data or in reply to command data. Thus, the load on the central controller is reduced.
That is, the local controller communicates with the central controller only when there is an event prompting it to communicate, such as a change in sensor data or a command from the central controller that cannot be executed or has been executed.
Thus, in particular, the local controller may be configured to transmit updated sensor data in case of a change of sensor data.
The flow means may be stop means for stopping the movement of one of the workpiece carriers relative to the conveyor. In this case, the workpiece carrier sensor may comprise a stop control detection device configured to detect the presence of a workpiece carrier reaching the detection device and/or to detect the presence of a workpiece on the workpiece carrier. Further, the actuator may include a stop control actuator configured to stop movement of the workpiece carrier relative to the conveyor.
Thus, in one embodiment, the stop means may be configured to stop the work piece carrier by movement of the work piece carrier itself. That is, the workpiece carrier may be stopped without command data from the central controller.
In another embodiment, the stopping means may be configured to stop the workpiece carrier only in response to command data received from the central controller. Thus, the central controller will need to issue a stop control command during the time it takes from the sensor detecting the presence of the workpiece carrier at or near the stop to the workpiece carrier reaching the actual stop position.
The stopping means may further comprise a tag reader and/or writer. The local controller may be a stop local controller operatively connected to the stop control detection device, the stop control actuation device and the tag reader/writer to receive detection signals from the stop control detection device, to transmit control signals to the stop control actuation device and to receive/transmit tag data from/to the tag reader/writer. The immobilization local controller may be configured to: receiving a sensor signal from a stop control detection device; receiving tag data from a tag reader/writer; transmitting sensor data corresponding to the sensor signal and the tag data to the central controller in the form of a stop event message; receiving a stop control command from a central controller, said command comprising an indication to release the work piece carrier and/or an indication of data to be written to the tag; and controls the actuator to release the workpiece carrier.
The tag data may comprise ID data and/or address data, and wherein the parking control command comprises an indication for writing modified ID data and/or tag data.
By allowing the tag data to be overwritten, a system may be provided that is partially autonomous in the sense that one or more steps may be performed without communicating with the central controller. For example, a predetermined sub-sequence of operations may be performed autonomously without involving a central controller, wherein one or more operations of such sub-sequence provide updated tag data that may indicate what steps have been performed and/or where the workpiece carrier is to go next.
In particular, the tag data may be rewritten or reset to indicate that the workpiece carrier is empty or otherwise not carrying any valid workpieces, whereby such empty or invalid workpiece carriers may flow through the conveyor system without the local controller communicating with the central controller. The stopping means may be configured to stop the workpiece carrier autonomously, i.e. without interacting with the central controller. Thus, communication may be postponed until the local controller has determined that the workpiece carrier is in place and has read the data of the workpiece carrier.
The stopping device may further comprise a work piece carrier arrival detector, a work piece carrier position detector and/or a work piece presence detector. Depending on which detector(s) is/are present, the stop event message may further comprise data indicating that the workpiece carrier reaches the stop flow controller, data indicating whether the workpiece carrier is in a predetermined stop position, and/or data indicating whether a workpiece is present. Thus, further intelligence can be delegated to the local controller; the local controller will not communicate with the central controller until all data is obtained.
The stop device may further comprise at least one zone status detector configured to detect the presence of a workpiece carrier on a downstream side of the stop control actuation device, and in this case the event message may further comprise data indicating whether the zone is clear.
The conveyor may be configured to provide at least one Y-intersection having an input conveyor line and a greater number of output conveyor lines, and the flow device is a switch device for selectively transferring input workpiece carriers to one of the output conveyor lines. In this case, the actuator may include a switch actuating device configured to selectively transfer the workpiece carrier to the one of the output conveyor lines, the workpiece carrier sensor may include a switch zone state detector configured to detect the presence or absence of the workpiece carrier on a downstream side of the switch actuating device, and the local controller may include a switch local controller operatively connected to the switch actuating device and the switch zone state detector to send and receive control signals to and from the switch actuating device. The local controller may be configured to receive switch control commands from the central controller, receive signals from the switch zone state detector, and send switch reply messages indicating switch zone state and switch position.
Thus, the switch device may be triggered by a switch command rather than by the arrival of a work piece carrier. For example, the stop device may be disposed upstream of the switch device and may not release the stopped workpiece carrier until the switch device has been properly actuated.
The central controller may be configured to: determining to which output line the workpiece carrier is to be directed based on the flow plan; sending switch control commands to the switch device to indicate a desired switch position; and receives switch reply messages.
The local controller may be configured to determine whether to override said receiving the switch control command from the central controller, said receiving a signal from the switch zone state detector, and said sending a switch reply message based on the sensor signal or the sensor data, and autonomously control the switch actuating device to assume a desired position.
Thus, depending on e.g. the tag data, or in case the workpiece carrier is empty or the workpiece may e.g. be positioned incorrectly or otherwise malfunction, the local controller may be allowed to autonomously control the switch-outs such that the local controller may make a decision to transfer such workpiece carrier. Instead, the workpiece carrier may be centrally controlled instead when it carries valid workpieces. According to a second aspect, there is provided a method of operating a conveyor system comprising a plurality of workpiece carriers, each workpiece carrier being adapted to support at least one workpiece during transport; at least one conveyor adapted to transport the workpiece carriers; at least one flow device for controlling movement of the workpiece carriers relative to the conveyor, the flow device comprising a local controller, at least one workpiece carrier sensor, and at least one actuator; and a central controller in data communication with the flow device and having a memory containing a flow plan including data describing an expected flow of workpieces in the conveyor system. The method comprises the following steps: receiving a sensor signal at the local controller via a signal interface; converting the sensor signal to a data format to form sensor data; transmitting the sensor data to the central controller via a data interface; the method includes receiving command data from the central controller via the data interface, providing an actuator control signal in response to the command data, and providing the actuator control signal to the actuator. The method may further comprise: receiving at least two sensor signals from at least two different sensors; converting the sensor signal into a predetermined data format; and transmitting the sensor data in a single event message.
In the method, receipt of the sensor signal may trigger the local controller to transmit the sensor data to the central controller.
Alternatively, the command data may trigger the local controller to send the sensor data to the central controller, for example, in the event that the current sensor data indicates that the command data cannot be executed.
In the method, the command data may be received by the local controller in response to said transmission of the sensor data to the central controller.
The method may further comprise: based on the sensor signal and/or the sensor data, it is determined whether to override the steps of transmitting the sensor data to the central controller and receiving the command data from the central controller, and then autonomously generate the command data.
Thus, if it decides to override, the local controller itself will generate and execute the command data without having to communicate with the central controller in advance.
According to a third aspect, a stopping device for use in a conveyor system configured to transport a plurality of workpiece carriers by means of a conveyor is provided, the device being configured to stop movement of one of the workpiece carriers relative to the conveyor. The stopper device includes: a stop control detection device configured to detect the presence of a workpiece carrier reaching the detection device and/or to detect the presence of a workpiece on the workpiece carrier; and a stop control actuator configured to stop movement of the workpiece carrier relative to the conveyor; a tag reader and/or writer; and a stop local controller operatively connected to the stop control detection device, the stop actuation device, and the tag reader/writer to receive detection signals from the stop control detection device, transmit control signals to the stop control actuation device, and receive/transmit tag data from/to the tag reader/writer. The immobilization local controller is configured to: receiving a sensor signal from a stop control detection device; controlling a stop control actuator to stop the workpiece carrier in response to the sensor signal; receiving tag data from a tag reader/writer; transmitting sensor data corresponding to the sensor signal and the tag data to the central controller in the form of a stop event message; receiving a stop control command from a central controller, said command comprising an indication to release the work piece carrier and/or an indication of data to be written to the tag; and controls the stop control actuator to release the workpiece carrier.
The immobilization local controller may be configured to receive the immobilization control command in response to said transmission of the sensor data to the central controller.
The tag data may comprise ID data and/or address data and the immobilization control command may comprise an indication for writing modified ID data and/or tag data. The stopping device may further comprise a work piece carrier arrival detector, a work piece carrier position detector and/or a work piece presence detector. The stop event message further includes data indicating that the workpiece carrier reaches the stop flow controller, data indicating whether the workpiece carrier is at a predetermined stop position, and/or data indicating whether a workpiece is present.
The stop device may further comprise at least one zone status detector configured to detect the presence of a workpiece carrier on a downstream side of the stop control actuation device, and wherein the stop event message further comprises data indicating whether the zone is clear.
A merge device for use in a conveyor system configured to transport a plurality of workpiece carriers by means of a conveyor and comprising at least one Y-cross having at least two input conveyor lines and an output line may be provided, the merge device being configured for selectively transferring the input workpiece carriers to the output conveyor lines. The above-described contents are associated with a respective one of the input delivery lines.
The local controller may be configured to determine whether to override the steps of transmitting the sensor data to the central controller and receiving the command data from the central controller based on the sensor signal, the tag data, and/or the sensor data, and then autonomously generate the immobilization control command.
According to a fourth aspect, there is provided a switch arrangement for use in a conveyor system configured to transport a plurality of workpiece carriers by means of a conveyor and including at least one Y-intersection having an input conveyor line and a greater number of output conveyor lines, the switch arrangement being configured to selectively transfer one of the workpiece carriers to one of the output conveyors. The switch device comprises: a switch actuating device configured to selectively transfer the workpiece carrier from the conveyor; a switch zone state detector configured to detect the presence of a work carrier on a downstream side of the switch actuator, and a switch local controller operatively connected to the switch actuator and the switch zone state detector to send control signals to the switch actuator and to receive detection signals from the zone state detector. The local controller is configured to receive switch control commands from the central controller via the data interface, receive detection signals from the switch zone state detector, and send switch reply messages to the central controller via the data interface indicating switch zone state and switch position.
A merge/switch apparatus may be provided for use in a conveyor system configured to transport a plurality of workpiece carriers by means of a conveyor and including a merge/switch intersection having at least two input conveyor lines and at least two output conveyor lines. The merging/diverging device comprises a first stop device and a second stop device associated with a respective one of the input conveyor lines, as described above, and a switch device arranged downstream of the stop control actuating device, as described above.
The switch local controller may be configured to send the switch reply message in response to having received the switch control command.
The switch local controller is configured to determine whether to override said receiving the switch control command and said sending switch reply message from the central controller and to autonomously control the switch actuating device to assume the predetermined position based on the detection signal or tag data received from the tag reader. According to a fifth aspect, there is provided a conveyor system comprising:
a plurality of workpiece carriers, each adapted to support at least one workpiece during transport; a conveyor adapted to convey a work piece carrier; at least one stop device as described above configured to stop movement of the workpiece carrier along the conveyor; and
a central controller in data communication with the stop device and having a memory device containing a flow plan including data describing an expected flow of workpieces in the conveyor system. The central controller is configured to: receiving the stop event message from the immobilizer; determining whether to release the workpiece carrier based on the tag data and the flow plan; and sends the stopping control command to the stopping device.
The central controller may be configured to determine whether to release the workpiece carrier and send the stop control command in response to receiving the stop event message.
The conveyor system may further include at least one wye cross having an input conveyor line and a greater number of output conveyor lines, at least one switch arrangement as described above associated with the wye cross. In this case, the central controller may be further configured to generate a switch control command based on the flow plan and transmit the switch control command to the switch device.
The central controller may be further configured to receive the switch reply message from the switch device and also determine whether to release the workpiece carrier based on the switch position and/or switch zone status.
The switch device may be disposed downstream of the stop control actuator device, and the central controller may be further configured to: determining to which output line a workpiece carrier is to be directed based on the tag data and the flow plan; and sends switch control commands to the switch device to indicate the desired switch position.
The central controller may be further configured to: receiving a switch reply message indicating a current switch position and switch zone state from the switch device; and also determines whether to release the workpiece carrier and/or to which output conveyor line such released workpiece carrier is directed based on the switch location and/or switch zone status.
The conveyor system may further comprise at least one Y-cross having at least two input conveyor lines and one output line, and at least one combining device as described above. Thus, the central controller may be further configured to: receiving a second stop event message from the stopping device, the stop event message including tag data; determining whether to release any workpiece carriers based on the stop event message, the tag data, and the flow plan; and sends a stopping control command to one of the stopping devices.
The conveyor system may further include at least one Y-intersection having at least two input conveyor lines and at least two output conveyor lines, and at least one merge/switch arrangement as described above. Thus, the central controller is further configured to: receiving a stop event message from a stopping device, the stop event message including tag data; determining whether to release any workpiece carriers and to which output conveyor line such released workpiece carriers are directed based on the event message, the tag data and the flow plan; sending a switch control command to the switch device, thereby indicating a desired switch position; and sends a stopping control command to one of the stopping devices.
In an alternative, the conveyor may be configured to provide at least one merge having at least two input conveyor lines and one output line, wherein the workpiece carrier sensor comprises a stop control detection device on each input conveyor line, the stop control detection device being configured to detect the presence of a workpiece carrier reaching the detection device and/or to detect the presence of a workpiece on the workpiece carrier; and the actuator may include a respective stop control actuator on each of the infeed conveyors configured to stop movement of the work carrier (WPC) relative to the conveyor.
The workpiece carrier sensor may comprise at least one merge area status detector configured to detect the presence of a workpiece carrier on a downstream side of the stop control actuator. The stop device further includes a respective tag reader and/or writer on each input conveyor. The local controller may be a merge local controller operatively connected to the stop detection device, the stop actuation device and the tag reader/writer to receive the detection signal from the stop detection device, to receive the zone state signal from the merge zone state detector, to transmit the control signal to the stop actuation device and to receive/transmit the tag data from/to the tag reader/writer. The local controller is configured to: receiving a sensor signal from at least one of the stop control detection devices; receiving tag data from an associated tag reader/writer; receiving a region status from a merge region status detector; transmitting data corresponding to the sensor signals, the zone status and the tag data to the central controller in the form of a consolidated event message; receiving a consolidated control command from the central controller, the command including at least one of an indication as to which stop control actuators are allowed to release their workpiece carriers; and controls the actuator to release the workpiece carrier.
According to another aspect, there is provided a production system comprising at least two operating stations selected from the group consisting of processing stations, additive manufacturing stations, surface treatment stations and assembly stations, the production system comprising a conveyor system as described above configured to transport workpieces from one operating station to another.
Drawings
Fig. 1 is a schematic depiction of a conveyor system according to the present disclosure.
Fig. 2 is a schematic depiction of the stop device.
Figure 3 is a schematic depiction of the switch device.
Fig. 4 is a schematic depiction of a merged arrangement.
Fig. 5 is a schematic depiction of a merge/diverge arrangement.
Detailed Description
The system according to the present disclosure is a system for transporting work pieces WP between operator stations 11a, 11b, 11c, 11 d. The work pieces WP are transported on a work piece carrier WPC. One or more operating unit conveyors 10a, 10b, 10c and one side rail 10d are connected to the main conveyor(s) 10. Each operating unit conveyor 10a, 10b, 10c or side rail 10d is adapted to convey workpieces from the associated main conveyor 10 to an operating station 11a, 11b, 11c, 11d, on which the workpieces are operated on or loaded or unloaded.
Fig. 1 schematically illustrates a conveyor system comprising a main conveyor 10, three workstation conveyors 10a, 10b, 10c, side rail conveyor 10d, loading station 12, unloading station 13, and a plurality of workstations 11a, 11b, 11c, 11 d. A plurality of work piece carriers WPC are provided to carry work pieces WP between different stations 11a, 11b, 11c, 11d served by the conveyor system.
Each work carrier and/or each work piece may comprise an id tag by means of which the work carrier or work piece can be identified. Such a tag may include an id that is unique to a particular workpiece, or the same id for each workpiece at the same point in the production process.
Thus, in the system disclosed herein, the work pieces may be transported on work piece carriers that ensure proper interaction with the conveyor belt. The workpiece carrier may comprise a conveyor interface which may be designed to ensure that the workpiece carrier will follow the conveyor correctly when it is intended to move the workpiece carrier, and may allow relative movement between the conveyor and the workpiece carrier when the workpiece is to be stopped. The workpiece carrier may further comprise a workpiece interface, which may be adapted to ensure that the workpiece is safely carried by the workpiece carrier. The label, which may be machine readable and/or writable, may be provided on the work piece carrier instead of on the work piece.
At the workstations 11a, 11b, 11c, 11d and at the loading station 12 and the unloading station 13, stop means 3 are provided, which will be further described with reference to fig. 2.
At the conveyor bifurcation, a
At the conveyor merge, a merge arrangement 5 is provided, which will be further described with reference to fig. 4.
At the conveyor merge/diverge, a merge/diverge arrangement 6 is provided, which will be further described with reference to fig. 5.
All
The
Communication between the
Fig. 2 schematically illustrates a stop device, i.e. a device having the function of stopping a work piece carrier arriving at the conveyor and subsequently releasing the work piece carrier.
The stopping device 3 comprises a local controller 30, which may comprise processing means, a memory and an interface for receiving sensor signals and providing control signals. The local controller 30 also has a communication interface for communicating with the
The stop device 3 may comprise a work piece carrier arrival detector 31, i.e. a detector configured for detecting moving work piece carriers that are about to arrive at the conveyor. The detection may be mechanical, optical (camera, photo-sensor, laser rangefinder), radar, acoustic (ultrasound) or capacitive. A single detector may use two or more detection techniques.
The stopping device 3 may comprise a work piece carrier position detector 32, i.e. a detector configured to detect whether the work piece carrier is in a predetermined position. Preferably, the detector is configured to detect that the workpiece carrier is stationary at the predetermined position as a result of the workpiece carrier having been successfully stopped by the stopping means. The detection may be mechanical, optical (camera, photo-sensor, laser rangefinder), radar, acoustic (ultrasound) or capacitive. A single detector may use two or more detection techniques.
The stop device 3 may comprise a workpiece detector 33, i.e. a detector arranged for detecting the presence of a workpiece on the workpiece carrier WPC. The detection may be mechanical, optical (camera, photo-sensor, laser rangefinder), radar, acoustic (ultrasound) or capacitive. A single detector may use two or more detection techniques.
The stopping device 3 comprises a tag reader and/or writer 34, i.e. a device for reading a tag on a work carrier or on a work piece, which tag contains data that can identify the work carrier or the work piece. In some applications, a tag reader may be sufficient, such as for any application that only requires identification of the workpiece carrier or workpiece, or an application that does not wish to retain updated data on the workpiece carrier or workpiece itself. This may be the case if the entire production log is stored in the
However, in some cases, it may be desirable to update the tag data. This may be the case if some decision rights are to be delegated to the
The tags may be read by any reading technique including, but not limited to, RFID, NFC, optical, magnetic, capacitive, and the like.
The stopping device 3 further comprises a stopping actuator 35, i.e. a device that mechanically stops the movement of the work piece carrier relative to the conveyor. The actuator may be an electric actuator. Alternatively, the actuator may be driven hydraulically or pneumatically under the control of the controller 30. The stop actuator 35 may comprise an arm or shoulder that is rotatable or translationally movable, for example, between a passive position that does not affect movement of the workpiece carrier and an active position that prevents movement of the workpiece carrier relative to the conveyor.
The stopping device 3 may further comprise a zone status detector 36 configured to determine whether a zone downstream of the actuator 35 is free. In general, this region may be immediately adjacent to the actuator 35, such as within 1 to 10 workpiece carrier lengths and/or upstream of any immediately
The local controller 30 of the stopping device 3 operates as follows.
When the work carrier WPC reaches the stopping device 3, it is detected by the work carrier arrival detector 31, which provides a signal to the local controller 30. The local controller provides a stop signal to the stop actuator 35 whereby the actuator 35 stops the work piece carrier from its movement relative to the conveyor 10, 10a, 10b, 10c, 10 d. Once the work carrier WPC has stopped, the work carrier in-position detector 32 provides a work carrier in-position signal to the local controller 30.
The workpiece detector 33 (optionally) detects the presence of a workpiece on the workpiece carrier WPC and provides a corresponding signal to the local controller 30.
The tag reader 34 reads the tag data and forwards the tag data to the local controller 30.
Zone status detector 36 (optionally) detects whether its monitored zone downstream of stop actuator 35 is clear and provides a zone status signal to local controller 30.
The local controller 30 provides a stop event message to the
If any sensor data is to be changed, the local controller 30 may provide an updated stop event message at any time. For example, the workpiece may be loaded onto the workpiece carrier such that the workpiece detector signal changes, or the zone downstream of the actuator 35 may be unblocked such that the zone status detector signal changes.
As a primary rule, the local controller 30 maintains the workpiece carrier in a stopped state until it receives a stop control command from the
The
The
Once the
The stop control command may include an indication that the workpiece carrier is to be released. Alternatively, the stop control command may include tag data to be written to the tag of the workpiece carrier by the tag reader/writer 34. Still alternatively, the immobilizer control command may include identification information for identifying the immobilizer device 3 for which the immobilizer control command is intended.
Thus, the stop control command is issued in response to a specific stop event message, which means that the decision on what action to take based on the arrival of the workpiece carrier at the local controller is made by the central controller and not by the local controller. That is, the immobilization control command is issued in real time.
Fig. 3 schematically shows a
The
The
The switch actuator may include a switch position detector or memory based on which feedback regarding switch position may be provided to the
The
The operation of the
The operation of the switch device is typically initiated by a switch command from the
The switch control commands typically include an indication of the desired switch position. Alternatively, the switch control command may contain information identifying the desired
Upon receipt of a switch control command, the
If the zone is free and the switch is in the correct position, the reply message from the
Thus, in response to a specific request by the central controller, a reply message is sent from the
If the area is free and the switch is in the correct position, the reply message will be similar, but delayed until the switch reaches the desired position.
If the area is not free, a reply message from
If the status of the zone status detector becomes idle, an updated reply message will be generated, in which case the
Therefore, the
Fig. 4 schematically shows a merging arrangement 5, i.e. an arrangement for handling merging of at least two incoming conveyor lines into one conveyor line.
Basically, the merging arrangement comprises a pair of
Each of the stop means 3a, 3b may be designed and function as indicated above with reference to fig. 2.
Therefore, the operation of the merging arrangement 5 will be described.
When the workpiece carrier reaches one of the stopping
The
If the workpiece carrier reaches both
Fig. 5 schematically shows a merging/diverging arrangement 6, i.e. an arrangement for handling merging of at least two incoming and at least two outgoing transport lines.
The merging/diverging arrangement essentially consists of the merging arrangement described with reference to fig. 5 and the diverging arrangement described with reference to fig. 4.
That is, the
In this case, the
The
It is possible to design a single hardware unit which may have different operating modes, so that it can be used as a stop device 3, a
When communicating with the central controller, the local controller may send data, such as id data of the flow device, that enables the central controller to identify it.
The message to the central controller may further include an indication of the flow device status, an error code, and/or a code indicating a configuration code, i.e., indicating the type of device it is operating as (i.e., a stop device or a switch device).
The embodiments discussed above are based on the concept that all decisions affecting the flow of the workpiece carrier are made by the central controller. Thus, whenever a local controller receives a sensor input (such as detection of a work piece carrier), the information of that input is communicated to the central controller, and no action is taken until command data is received from the central controller.
On the other hand, some very basic operations are delegated to the local controller, for example, as described above, stopping the decision of the work piece carrier to arrive. I.e. the decision to release only the work piece carrier needs to be made by the central controller.
Although not yet completed, further delegation of the task to the local controller may also be allowed. For example, the local controller may be configured to make some decisions based on its sensor data, whereby the step of communicating with the central controller may be overridden or bypassed.
One such example is to allow the local controller to make a decision when an empty workpiece carrier, or a workpiece carrier carrying a wrongly arranged or damaged workpiece, is detected. Since such workpiece carriers may be destined for specific destinations, such as buffers, reject stations or manual processing stations, they may be allowed to proceed towards these destinations without communicating with the central controller.
The tag carried by such a work piece carrier may thus be updated to indicate that the work piece carrier is one that allows the local controller to make decisions on it. For example, it is possible to write an indication of a workpiece to a tag when it is found to be lost or damaged, so that its status is changed from central control to local control.
In addition, local control of the sub-series of operations may be allowed. For example, the central controller may control the work piece carrier until entry into such a sub-series of operations, whereby the tag data is updated during or after each operation, and when the sub-series of operations is completed, control of the work piece carrier is taken over by the central controller.
In the case of a stop control, the most important decision may be to release the workpiece carrier immediately when certain conditions are met.
In the case of a switch controller, the most important decision may be to immediately transfer the work piece carrier.
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