阅读说明：本技术 负载驱动装置和负载驱动装置的控制方法 (Load driving device and control method for load driving device ) 是由 片渕广生 角谷清臣 于 2020-03-13 设计创作，主要内容包括：本发明提供稳定性(线性度)高的负载驱动装置及其控制方法,在将多个感性负载并联连接的负载驱动装置中,即使在特定的感性负载中暂时检测到反向电流的情况下,也能够继续正常动作而无需停止负载驱动装置。(The invention provides a load driving device with high stability (linearity) and a control method thereof, wherein in the load driving device which connects a plurality of inductive loads in parallel, even if reverse current is temporarily detected in a specific inductive load, the normal operation can be continued without stopping the load driving device.)

1. A load driving apparatus, comprising:

a first switching element;

a second switching element;

a current and direction detecting unit for detecting a forward current and a reverse current flowing through the first switching element;

a current and direction detecting unit for detecting a forward current and a reverse current flowing through the second switching element;

a control unit that calculates an average current based on signals from the current and direction detection units;

a driving unit that drives the first switching element and the second switching element based on a deviation between the average current and a target current; and

a plurality of inductive loads, one end of each of which is connected to the common current path of the first switching element and the second switching element, and the other end of each of which is connected to the common wiring at one point,

wherein the current monitoring is continued even when the current and direction detecting unit detects a reverse current when the second switching element is on and the average current calculated by the control unit is in a direction opposite to that in a normal state.

2. The load driving apparatus according to claim 1, wherein:

even when the average current calculated by the control unit is in the direction opposite to the normal state, the feedback control is continued to eliminate the situation and the average current is brought close to the target current.

3. The load driving apparatus according to claim 1, wherein:

the current and direction detection unit detects the current or the average current calculated by the control unit, and has an abnormality determination threshold for determining abnormality of the common wiring in a current range in a direction opposite to a normal state, determines that the common wiring is abnormal when the abnormality determination threshold is exceeded, and controls one inductive load or a plurality of inductive loads based on abnormality determination processing by the control unit.

4. The load driving apparatus according to claim 3, wherein:

in the setting of the abnormality determination threshold, the abnormality determination threshold is set to have a magnitude of a current that can operate the inductive load or to be lower than the magnitude in a current range in a direction opposite to a normal time.

5. The load driving apparatus according to claim 1, wherein:

the common wiring is a GND line.

6. The load driving apparatus according to claim 5, wherein:

the second switching element is a switching element connected to a low side.

7. The load driving apparatus according to claim 1, wherein:

the common wiring is a power supply line.

8. The load driving apparatus according to claim 7, wherein:

the second switching element is a switching element connected to the high side.

9. A method for controlling a load driving apparatus for connecting a plurality of inductive loads in parallel, comprising:

detecting a current value and a current direction of each of the plurality of inductive loads,

in the case where the detected direction of the current is the direction opposite to the prescribed direction of the current,

comparing the detected current value with a prescribed threshold value,

when the detected current value is lower than the predetermined threshold value, the operation of the load driving device is continued.

10. The control method of the load driving apparatus according to claim 9, wherein:

and stopping the operation of the load driving device when the detected current value is equal to or greater than the predetermined threshold value.

11. The control method of the load driving apparatus according to claim 9, wherein:

a current value and a current direction are detected for each of a plurality of switching elements constituting the load driving device.

12. The control method of the load driving apparatus according to claim 9, wherein:

wherein the opposite side of the inductive loads connected to the load driving device is connected to a common wiring,

the common wiring is a GND line.

13. The control method of the load driving apparatus according to claim 9, wherein:

wherein the opposite side of the inductive loads connected to the load driving device is connected to a common wiring,

the common wiring is a power supply line.

Technical Field

The present invention relates to a structure of a load driving device for driving and controlling an inductive load such as a solenoid valve, and to control thereof, and more particularly to a technique that can be effectively applied to a vehicle-mounted load driving device that requires control stability (linearity).

Background

Conventionally, a vehicle automatic transmission (transmission system) uses a mechanism for controlling a plurality of solenoid valves. In a typical transmission system, a plurality of inductive loads are connected to 1 controller (load driving device), and common wiring is used on the vehicle side of the inductive loads for the purpose of reducing the number of connector terminals and achieving miniaturization.

As a background art in this field, for example, there is a technology as in patent document 1. Patent document 1 discloses a "wire harness connection method capable of reducing noise radiation of a solenoid valve control circuit and improving interference resistance", in which one ends of a plurality of solenoid valves are commonly wired to connection portions between the plurality of solenoid valves and their control devices.

Patent document 2 discloses a "driving device that realizes highly accurate current control based on the voltage across the current sensing resistor and detects the direction of the current flow to detect disconnection of the common wiring", in which a current monitoring unit of each control driving unit monitors a current change in the common current path and determines whether or not disconnection abnormality occurs in the common wiring based on the current change.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-97850

Patent document 2: international publication No. 2017/057682

Disclosure of Invention

Technical problem to be solved by the invention

When a plurality of inductive loads are connected to 1 load driving device as described above, and the vehicle side of the inductive loads (the side opposite to the side of the loads connected to the load driving devices) is connected by the common wiring, there is a concern that the influence of a reverse current generated by a current flowing from one inductive load to another inductive load may be exerted.

The conventional load driving device is configured to stop the operation of the load driving device when a reverse current is detected, and may determine that an abnormality has occurred although the common wiring is in a normal state.

In a vehicle automatic transmission (transmission system), when the operation of a load driving device is temporarily stopped, a shift shock is deteriorated, that is, the stability (linearity) of control is lowered, and the riding comfort (driving comfort) of a passenger is deteriorated.

Therefore, an object of the present invention is to provide a load driving apparatus having high stability (linearity) and a control method thereof, in which even when a reverse current is temporarily detected in a specific inductive load, a normal operation can be continued without stopping the load driving apparatus in which a plurality of inductive loads are connected in parallel.

Means for solving the problems

In order to solve the above problem, the present invention provides a load driving apparatus, including: a first switching element; a second switching element; a current and direction detecting unit for detecting a forward current and a reverse current flowing through the first switching element; a current and direction detecting unit for detecting a forward current and a reverse current flowing through the second switching element; a control unit that calculates an average current based on signals from the current and direction detection units; a driving unit that drives the first switching element and the second switching element based on a deviation between the average current and a target current; and a plurality of inductive loads, one end of each of which is connected to a common current path of the first switching element and the second switching element, and the other end of each of which is connected to the common wiring at one point, wherein the current monitoring is continued even when the current and direction detection unit detects a reverse current when the second switching element is turned on and the average current calculated by the control unit is in a direction opposite to that in a normal state.

Further, the present invention provides a method of controlling a load driving apparatus in which a plurality of inductive loads are connected in parallel, wherein a current value and a current direction of each of the plurality of inductive loads are detected, the detected current value is compared with a predetermined threshold value when the detected current direction is opposite to the predetermined current direction, and the operation of the load driving apparatus is continued when the detected current value is lower than the predetermined threshold value.

Effects of the invention

In the load driving device in which a plurality of inductive loads are connected in parallel, the present invention can continue normal operation without stopping the load driving device even when a reverse current is temporarily detected in a specific inductive load, and can realize a load driving device with high stability (linearity) and a control method thereof.

Thus, in a vehicle automatic transmission (transmission system) that drive-controls a plurality of solenoid valves, it is possible to reduce the risk of deterioration of shift shock, and to improve the riding comfort (driving comfort) of the occupant.

Technical problems, technical features, and technical effects other than those described above will be apparent from the following description of the embodiments.

Drawings

Fig. 1 is a diagram showing a circuit configuration of a typical load driving device in a conventional vehicular automatic transmission (transmission system).

Fig. 2 is a diagram showing a circuit configuration of a load driving device according to embodiment 1 of the present invention.

Fig. 3 is a timing chart showing an operation (action) of the load driving device of fig. 1.

Fig. 4 is a timing chart showing an operation (action) of the load driving device of fig. 2.

Fig. 5 is a flowchart showing an operation flow of an abnormality diagnosis function of the common wiring in the load driving device of fig. 1.

Fig. 6 is a flowchart showing an operation flow of an abnormality diagnosis function of the common wiring in the load driving device of fig. 2.

Fig. 7 is a diagram showing a circuit configuration of a load driving device according to embodiment 2 of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted for redundant parts.

Example 1

A configuration of a load driving device and a control method thereof according to embodiment 1 of the present invention will be described with reference to fig. 1 to 6.

In order to make the structure of the present embodiment easy to understand, a conventional load driving device will be described with reference to fig. 1, 3, and 5. Fig. 1 is a circuit configuration diagram of a conventional common load driving device given as a comparative example.

As shown in fig. 1, the conventional load driving device includes driver units Dr1-1 to Dr1-5, control units 1-9 for controlling the driver units Dr1-1 to Dr1-5, and a connector terminal Co1 capable of connecting a plurality of inductive loads in parallel.

The driver unit Dr1-1 includes a first switching element 1-1, a second switching element 1-2, a first current detection switching element 1-3 connected in parallel with the first switching element 1-1, a second current detection switching element 1-4 connected in parallel with the second switching element 1-2, a current detection unit 1-5 of the first current detection switching element 1-3, a current detection unit 1-6 of the second current detection switching element 1-4, a first PWM drive unit 1-7 for driving the first switching element 1-1 and the first current detection switching element 1-3, a second PWM drive unit 1-8 for driving the second switching element 1-2 and the second current detection switching element 1-4, and a current detection switching element 1-1 connected to a common current path between the first switching element 1-1 and the second switching element 1-2 A current and direction detecting part 1-11 for detecting the current and the direction thereof based on the voltage at both ends of the current detecting resistor 1-10.

The control section 1-9 calculates an average current based on signals from the current detection section 1-5 and the current detection section 1-6.

The driver portions Dr1-2 to Dr1-5 have the same functions as the driver portion Dr 1-1.

The driver portions Dr1-1 to Dr1-5 are connected to the connector terminal Co 1. The driver units Dr1-1 to Dr1-5 are connected to connector terminals Co1-1 to Co1-5, which are one ends of inductive loads SL1-1 to SL1-5, respectively, and the other ends of the inductive loads SL1-1 to SL1-5 are connected to common lines 1-17 via lines 1-12 to 1-16, respectively.

Fig. 3 is a timing chart showing an operation (action) of the conventional load driving device shown in fig. 1. Fig. 3 a to D show the operations at positions a to D in fig. 1, respectively. By turning the first switching element 1-1 and the second switching element 1-2 ON/OFF alternately as shown in timing charts 3-1 and 3-2 of fig. 3, a current flows to the inductive load SL1-1 as shown in timing chart 3-4.

At this time, when a current flows to the inductive load SL1-2 as shown in the timing chart 3-3, a current (reverse current) also flows to the inductive load SL 1-1. As shown in the timing chart 3-4, the difference between the magnitude of the inflow current (reverse current) and the magnitude of the current flowing from the driver Dr1-1 to the inductive load SL1-1 becomes the current of the inductive load SL 1-1.

When the current flows in the opposite direction to the normal direction in the inductive load SL1-1, the current and direction detecting unit 1-11 detects the reverse current, and determines that the common wiring 1-17 is disconnected, and as shown in the timing chart 3-5, the control unit 1-9 asserts the disconnection flag (turns the flag OFF to ON) and turns OFF the first switching element and the second switching element of each of the driver units Dr1-1 to Dr1-5, thereby stopping the operation of the driver units Dr1-1 to Dr 1-5.

Fig. 5 is a flowchart showing an operation flow of the abnormality diagnosis function of the common wiring 1 to 17 in the load driving device of fig. 1. In any of the driver units Dr1-1 to Dr1-5, it is determined whether or not a reverse current flows when the second switching element is ON (step 5-1), and if it is determined that the current detected by the current and direction detection unit 1-11 is in the normal direction (no), the disconnection flag is deactivated (flag OFF) (step 5-2), and the normal operation of the driver units Dr1-1 to Dr1-5 is continued.

ON the other hand, if it is determined in step 5-1 that the current detected by the current and direction detector 1-11 is in the direction opposite to the normal state (reverse current) (yes), the disconnection flag is asserted (flag ON) (step 5-3), and the first switching element and the second switching element of each of the drivers Dr1-1 to Dr1-5 are both turned OFF (OFF), thereby stopping the operation of all the drivers Dr1-1 to Dr1-5 (step 5-4). As a result, the shift shock is worsened, resulting in a significant reduction in driving comfort.

Next, the load driving device of the present embodiment will be described with reference to fig. 2, 4, and 6.

Structure of load drive device

Fig. 2 is a circuit configuration diagram of the load driving device of the present embodiment. As shown in fig. 2, the load driving device of the present embodiment includes driver units Dr2-1 to Dr2-5, control units 2-9 for controlling the driver units Dr2-1 to Dr2-5, and a connector terminal Co2 capable of connecting a plurality of inductive loads in parallel.

The driver unit Dr2-1 includes a first switching element 2-1, a second switching element 2-2, a first current detection switching element 2-3 connected in parallel to the first switching element 2-1, and a second current detection switching element 2-4 connected in parallel to the second switching element 2-2, a current and direction detecting unit 2-5 for the first current detecting switching element 2-3, a current and direction detecting unit 2-6 for the second current detecting switching element 2-4, a first PWM driving unit 2-7 for driving the first switching element 2-1 and the first current detecting switching element 2-3, and a second PWM driving unit 2-8 for driving the second switching element 2-2 and the second current detecting switching element 2-4.

The control section 2-9 calculates an average current based on signals from the current and direction detecting section 2-5 and the current and direction detecting section 2-6.

The driver portions Dr2-2 to Dr2-5 have the same functions as the driver portion Dr 2-1.

The driver portions Dr2-1 to Dr2-5 are connected to the connector terminal Co 2. The driver units Dr2-1 to Dr2-5 are connected to connector terminals Co2-1 to Co2-5, which are one ends of inductive loads SL2-1 to SL2-5, respectively, and the other ends of the inductive loads SL2-1 to SL2-5 are connected to common lines 2-15 via lines 2-10 to 2-14, respectively.

Feedback control based on reverse current

Fig. 4 is a timing chart showing the operation (action) of the load driving device of the present embodiment shown in fig. 2. Fig. 4 a to D show the operations at positions a to D in fig. 2, respectively. By turning the first switching element 2-1 and the second switching element 2-2 ON/OFF alternately as shown in the timing charts 4-1 and 4-2 of fig. 4, a current flows to the inductive load SL2-1 as shown in the timing chart 4-4.

At this time, when a current flows to the inductive load SL2-2 as shown in the timing chart 4-3, a current (reverse current) also flows to the inductive load SL 2-1. As shown in the timing chart 4-4, the difference between the magnitude of the inflow current (reverse current) and the magnitude of the current flowing from the driver Dr2-1 to the inductive load SL2-1 becomes the current of the inductive load SL 2-1.

Even when the current flows in the opposite direction to the normal direction in the inductive load SL2-1, the average current can be continuously monitored by the control unit 2-9, and the target current value can be maintained with high accuracy even in the low instruction current range by performing feedback control based on the deviation between the temporary transient reverse current that changes with time and the target value.

Thus, even when the instruction current calculated by the control unit 2-9 is 0A, 0A can be reliably maintained while the feedback control is continued.

Operation flow of shared Wiring abnormality diagnosis function

In the abnormality diagnosis function of the common wiring 2 to 15, when the average current calculated by the control unit 2 to 9 is in the direction opposite to the normal state and exceeds a predetermined abnormality determination threshold value, it is determined that an abnormality (for example, disconnection) has occurred in the common wiring 2 to 15.

Fig. 6 shows an operation flow of the abnormality diagnosis function of the present embodiment. In any of the driver units Dr2-1 to Dr2-5, it is determined whether or not a reverse current flows when the second switching element is ON (step 6-1), and if it is determined that the current detected by the current and direction detector 2-6 or the average current calculated by the controller 2-9 is in the normal direction (no), the disconnection flag is disabled (flag OFF) (step 6-2), and the normal operation of the driver units Dr2-1 to Dr2-5 is continued.

On the other hand, when it is determined in step 6-1 that the current and the current detected by the direction detection unit 2-6 or the average current calculated by the control unit 2-9 are in the direction opposite to the normal state (reverse current) (yes), it is determined whether or not the magnitude of the reverse current is equal to or greater than a predetermined value (predetermined threshold) (step 6-3).

When the magnitude of the reverse current is lower than the predetermined threshold value (NO), the disconnection flag is deactivated (flag OFF) (step 6-2), and the normal operation of the driver units Dr2-1 to Dr2-5 is continued.

When the magnitude of the reverse current is equal to or greater than the predetermined value (predetermined threshold value) (yes), the disconnection flag is asserted (flag ON) (step 6-4), and the first switching element and the second switching element of each of the driver units Dr2-1 to Dr2-5 are both turned OFF, thereby stopping the operation of the driver units Dr2-1 to Dr 2-5.

Therefore, if the reverse current is in a region smaller than the abnormality determination threshold, the normal state can be continued without stopping the operation of the load driving device, and thus the situation in which the shift shock is worsened can be reduced.

Threshold for judging abnormality

In addition, the abnormality determination threshold is set to a value having a certain margin with respect to the magnitude of the current that can operate the inductive loads SL2-1 to SL2-5 or the magnitude of the current that can operate the inductive loads SL2-1 to SL 2-5.

The load driving device of the present embodiment is characterized in that, compared with the prior art, the current and direction detecting units 2-5 and 2-6 detect not only the magnitude of the current but also the direction in which the current flows, and even if the direction of the average current calculated by the control unit 2-9 is the direction opposite to the normal state, the driving of the inductive load SL2-1 by the driver unit Dr2-1 is not stopped, but the current is continuously monitored. In the present embodiment, the current value and the current direction are detected for each of the plurality of switching elements constituting the load driving device.

Even if the average current flows in the opposite direction, feedback control can be performed based on the deviation between the average current calculated by the control units 2 to 9 and the target value, and the target current value can be maintained with high accuracy even in the low indicated current range.

As explained above, the load driving apparatus of the present embodiment includes: a first switching element 2-1; a second switching element 2-2; a current and direction detecting unit 2-5 for detecting a forward current and a reverse current flowing through the first switching element 2-1; a current and direction detecting unit 2-6 for detecting a forward current and a reverse current flowing through the second switching element 2-2; a control unit 2-9 that calculates an average current based on signals from the current and direction detection units 2-5 and 2-6, respectively; a drive unit (driver unit Dr2-1) that drives the first switching element 2-1 and the second switching element 2-2 based on a deviation between the average current and the target current; and a plurality of inductive loads SL2-1 to SL2-5, each having one end connected to the common current path of the first switching element 2-1 and the second switching element 2-2 and the other end connected to the common wiring 2-15 at one point, wherein the current monitoring is continued even when the current and direction detector 2-5 detects a reverse current when the second switching element 2-2 is on and the average current calculated by the controller 2-9 is in a direction opposite to the normal state.

In addition, even when the average current calculated by the control unit 2-9 is in the direction opposite to the normal time, the feedback control is continued to eliminate the situation so that the average current approaches the target current.

The current and direction detector 2-5 or the average current calculated by the controller 2-9 has an abnormality determination threshold for determining abnormality of the common wiring 2-15 in a current range in a direction opposite to the normal state, determines that abnormality has occurred in the common wiring 2-15 when the abnormality determination threshold is exceeded, and controls one inductive load SL2-1 or a plurality of inductive loads SL2-1 to SL2-5 based on the abnormality determination processing by the controller 2-9.

In the setting of the abnormality determination threshold, the threshold is set in a current range in a direction opposite to that in the normal state, and the magnitude of the current that can operate the inductive loads SL2-1 to SL2-5 is equal to or lower than that.

In the present embodiment (fig. 2), the common wiring 2-15 is a GND line connected to GND, and the second switching element 2-2 is a switching element connected to a low side (low side).

In the load driving apparatus and the control method thereof according to the present embodiment, in the load driving apparatus in which a plurality of inductive loads are connected in parallel, even when a reverse current is temporarily detected in a specific inductive load, the normal operation can be continued without stopping the load driving apparatus, and the load driving apparatus and the control method thereof with high stability (linearity) can be realized.

Thus, in a vehicle automatic transmission (transmission system) that drive-controls a plurality of solenoid valves, it is possible to reduce the risk of deterioration of shift shock, and to improve the riding comfort (driving comfort) of the occupant.

In addition, the detection performance of the abnormality diagnosis of the common wiring 2 to 15 can be improved, and the reliability of the load driving device can be improved.

Example 2

The configuration of the load driving apparatus and the control method thereof according to embodiment 2 of the present invention will be described with reference to fig. 7. Fig. 7 is a circuit configuration diagram of the load driving device of the present embodiment.

Structure of load drive device

In example 1 (fig. 2), the common wiring 2-15 is a GND line, but this is premised on the high-side (high side) driving method of the inductive loads SL2-1 to SL 2-5. When the inductive loads SL2-1 to SL2-5 are driven in a low-side manner, the common wiring 2 to 15 is a battery line, as shown in fig. 7.

Operation flow of shared Wiring abnormality diagnosis function

The currents in the opposite directions flowing through the inductive loads SL2-1 to SL2-5 flow into the first switching element 2-1, and the currents in the opposite directions can be detected by the current and direction detector 2-5.

Therefore, when the driving method of the inductive loads SL2-1 to SL2-5 as in the present embodiment (fig. 7) is low-side driving, the operation flow is such that a reverse current flows when the first switching element is turned ON (ON) in step 6-1 of fig. 6.

In the present embodiment (fig. 7), the common wiring 2-15 is a power supply (battery) line connected to the power supply VB, and the second switching element 2-2 is a switching element connected to the high side.

The present invention is not limited to the above-described embodiments, and various modifications may be made.

For example, the above embodiments are described in detail to facilitate understanding of the present invention, but the present invention is not limited to the embodiments having all the structures described. Further, a part of the structure of one embodiment may be replaced with the structure of another embodiment, and the structure of another embodiment may be added to the structure of one embodiment. Some of the configurations of the embodiments may be added, deleted, or replaced with other configurations.

Industrial applicability

In the above-described embodiments, the load driving device of the automatic transmission (transmission system) for a vehicle using the linear solenoid valve has been described as an example, but the present invention is also applicable to, for example, an ink jet printer valve, a massage chair, or the like using a plurality of solenoid valves as pressure regulating valves or direction switching valves for oil or air.

Description of the reference numerals

1-1: a first switch element

1-2: second switch element

1-3: (first) Current detection switching element

1-4: (second) Current detection switching element

1-5: current detecting part (of first switching element)

1-6: current detecting part (of second switching element)

1-7: (first) PWM drive section

1-8: (second) PWM drive section

1-9: control unit

1-10: resistor for current detection

1-11: current and direction detecting part

1-12 to 1-16: the other end of the inductive load (wiring)

1-17: common wiring

Co 1: connector terminal (of load driving device)

Co1-1 to Co 1-5: one end of inductive load (connector terminal)

Dr 1-1-Dr 1-5: driver unit

SL1-1 to SL 1-5: inductive load

2-1: a first switch element

2-2: second switch element

2-3: (first) Current detection switching element

2-4: (second) Current detection switching element

2-5: current and direction detecting section (of first switching element)

2-6: current and direction detecting section (of second switching element)

2-7: (first) PWM drive section

2-8: (second) PWM drive section

2-9: control unit

2-10 to 2-14: the other end of the inductive load (wiring)

2-15: common wiring

Co 2: connector terminal (of load driving device)

Co2-1 to Co 2-5: one end of inductive load (connector terminal)

Dr 2-1-Dr 2-5: driver unit

SL2-1 to SL 2-5: inductive load

3-1 to 3-5: timing diagram (at the time of reverse current detection of the prior art)

4-1 to 4-5: timing chart (at the time of reverse current detection of embodiment 1)

5-1 to 5-4: (of the flow chart at the time of reverse current detection of the prior art) step

6-1 to 6-5: (of the flowchart at the time of reverse current detection of example 1) step