JP6377316B2 - Valve control device - Google Patents

Description

  The present invention relates to a valve control device that controls an electronic control valve.

  Conventionally, a technique for electronically controlling a valve by feedback control such as PID (Proportional Integral Derivative) control is known. As a valve to be controlled by this technique, for example, a cooling water valve for controlling the flow rate of cooling water for cooling the engine can be cited. This cooling water valve enables the flow rate of the cooling water to the path passing through the vicinity of the radiator for cooling the cooling water to be adjusted by the opening degree. Further, the cooling water passing through the path passing through the vicinity of the radiator is supplied to a water jacket in the vicinity of the engine. Further, according to the engine cooling system using such a cooling water valve, the flow rate of the cooling water supplied to the water jacket is adjusted by controlling the opening degree of the cooling water valve, and as a result, the cooling water The temperature of the cooled engine can be adjusted.

  In the engine cooling system described above, the cooling water valve is controlled based on the target opening calculated based on the target cooling water temperature for adjusting the engine temperature and the actual opening of the cooling water valve. When the actual opening reaches the target opening, the energization to the motor that drives the cooling water valve is stopped.

  As a related technique, the actual valve opening of the TCV is set as a target by calculating the allowable energization time of the TVC motor from the initial motor temperature calculated based on the A / D conversion value of the output signal of the cooling water temperature sensor. A technique for controlling the valve opening is known (for example, see Patent Document 1).

JP 2009-150328 A

  However, the cooling water valve has non-linear friction due to its mechanical configuration. Due to such friction, overshoot or undershoot occurs after the motor is de-energized, and the target opening is reduced. You may not be able to stay. In such a case, after energization is stopped, it is necessary to start energization of the motor again and cause the cooling water valve to reach the target opening, resulting in an increase in power consumption after reaching the target opening. There is. Such a problem is not limited to the cooling water valve, and may occur in all valves having nonlinear friction.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a valve control device capable of reducing power consumption after reaching a target opening degree in valve control.

  In order to solve the above-described problem, one aspect of the present invention is a valve control device that controls a driving device that drives a valve in an opening direction or a closing direction, and includes a target value of the valve opening and an opening of the valve. An operation amount calculation unit that calculates an operation amount of the driving device based on a deviation from an actual measurement value of the degree, a determination unit that determines whether or not an opening degree of the valve has reached the target value, and the determination unit A correction amount for calculating a correction amount that is an operation amount different from the operation amount based on the operation amount calculated by the operation amount calculation unit when it is determined that the opening degree of the valve has reached the target value A calculation unit.

  According to the present invention, power consumption after reaching the target opening can be reduced in the control of the valve.

It is a mimetic diagram showing an engine cooling system concerning this embodiment. It is a schematic diagram which shows a cooling water valve | bulb and a sealing member. It is a schematic diagram which shows a worm gear. It is a block diagram which shows the hardware constitutions of ECU. It is a functional block diagram which shows the function structure of a valve control apparatus. It is a flowchart which shows the operation | movement of a correction process. It is a figure which shows the output pattern A of a correction amount. It is a figure which shows the output pattern B of the correction amount. It is a figure which shows the output pattern C of a correction amount. It is a figure which shows the output pattern D of a correction amount. It is a figure which shows the output pattern E of the correction amount.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the engine cooling system according to the present embodiment will be described. FIG. 1 is a schematic diagram showing an engine cooling system according to the present embodiment.

  As shown in FIG. 1, the engine cooling system 1 according to the present embodiment includes an engine 11, a water jacket 12, a water pump 13, a cooling water valve 21, a motor 22, a position sensor 23, a water temperature sensor 24, an ECU (Engine Control). Unit) 31, a radiator 41, a heater 42, a throttle 43, a main flow path pipe 91, a sub flow path pipe 92, and a bypass flow path pipe 93.

  The engine cooling system 1 circulates cooling water through the main flow path pipe 91, the sub flow path pipe 92, or the bypass flow path pipe 93, and controls the temperature of the engine 11 by the water jacket 12.

  The engine 11 is an internal combustion engine of a vehicle such as an automobile. The water jacket 12 is provided in the vicinity of the engine 11 and cools the engine 11 with cooling water therein. The main flow path pipe 91 allows cooling water to flow into the radiator 41. The sub passage pipe 92 allows cooling water to flow into the heater 42 and the throttle 43. The bypass flow path pipe 93 allows the cooling water flowing out from the water jacket 12 to flow into the water pump 13. The cooling water that has flowed into the radiator 41, the heater 42, and the throttle 43 flows into the water pump 13. The water pump 13 allows cooling water to flow into the water jacket 12. The radiator 41 cools the cooling water. The heater 42 warms the passenger compartment. The throttle 43 controls the amount of exhaled air flowing into the engine 11.

  The cooling water valve 21 is a rotary valve, and an opening is provided in a part of the outer peripheral surface, and the cooling water flows into the main flow path pipe 91 and the sub flow path pipe 92 according to the opening degree. The motor 22 is a DC motor as an actuator that drives the cooling water valve 21. The position sensor 23 detects the opening degree of the cooling water valve 21 relative to the main flow path pipe 91 and the sub flow path pipe 92 by detecting the circumferential position of the cooling water valve 21. The water temperature sensor 24 detects the temperature of the cooling water. The ECU 31 includes a processor and a memory, and is a microcontroller that controls various operations related to the engine 11. In this embodiment, the ECU 31 detects the position of the cooling water valve 21 and the cooling water detected by the water temperature sensor 24 and the position sensor 23. It is assumed that the operation of the motor 22 is operated based on the temperature.

  With the configuration described above, the cooling water is cooled by the radiator 41 by circulating through the main flow path pipe 91, and is circulated without being cooled when passing through the bypass flow path pipe 93. Further, the engine cooling system 1 controls the temperature of the engine 11 by switching the cooling water circulation path according to the opening degree of the cooling water valve 21 and controlling the amount of cooling water flowing into the main passage pipe 91. .

  Next, the cooling water valve and the seal member will be described. FIG. 2 is a schematic view showing a cooling water valve and a seal member.

As shown in FIG. 2, seal members 91 a and 92 a are provided in the vicinity of the cooling water inlet of the main flow path pipe 91 and the sub flow path pipe 92 so as to cover the outer periphery thereof. The cooling water valve 21 changes the position of the opening with respect to the main flow path pipe 91 and the sub flow path pipe 92 by rotating in the circumferential direction about the rotation shaft 21a. The amount of cooling water flowing into the main flow path pipe 91 and the sub flow path pipe 92 is adjusted by the position of the opening. In such a configuration, nonlinear friction, such as a stick slip occurs between the cooling water valve 21 and the seal member 91a, 92 a. This non-linear friction or stick slip can be a factor that prevents the stopped cooling water valve from staying at the target opening.

  Next, the worm gear will be described. FIG. 3 is a schematic diagram showing the worm gear.

  As shown in FIG. 3, the driving force of the motor 22 includes a gear 81 provided on the rotation shaft of the motor 22, a gear 82 meshing with the gear 81, a gear 83 provided coaxially with the gear 82 and rotating integrally therewith, The gear 84 meshes with the gear 83, and the worm wheel 86 that is coaxially provided with the gear 84 and rotates integrally therewith, is transmitted to the worm wheel 86 that meshes with the worm 85. The transmitted driving force is transmitted to the cooling water valve 21 by the rotation shaft 86a of the worm wheel 86 connected to the rotation shaft 21a of the cooling water valve 21. In such driving force transmission, various nonlinear frictions occur between the gears. Further, in the worm gear constituted by the worm 85 and the worm wheel 86, a directional hysteresis is generated due to factors such as the twist direction and the twist angle of the worm 85. Such hysteresis is predetermined in a predetermined direction with respect to the target opening degree regardless of the operation direction of the cooling water valve 21 until the target opening degree is reached after the cooling water valve 21 is stopped. It can be a factor that causes the deviation. In the present embodiment, it is assumed that the hysteresis due to the worm gear is larger in the opening direction than in the closing direction. In this case, after the coolant valve 21 has reached the target opening degree, if it has been operated in the opening direction until then, the cooling water valve 21 is displaced in the forward direction, and if it has been operated in the closing direction, the displacement is reversed in the reverse direction. Arise.

  Next, the hardware configuration of the ECU will be described. FIG. 4 is a block diagram showing a hardware configuration of the ECU.

  As shown in FIG. 4, the ECU 31 includes a CPU (Central Processing Unit) 311, a memory 312, an input / output interface 313, and a drive circuit 314. The CPU 311 and the memory 312 cooperate to perform processing related to the control of the cooling water valve 21. The input / output interface 313 is an interface related to the input / output of the CPU 311, and the CPU 311 acquires the detection results by the position sensor 23 and the water temperature sensor 24 through the input / output interface 313, and the motor through the input / output interface 313. A signal corresponding to the operation amount 22 is output to the drive circuit 314. The drive circuit 314 is a PWM circuit that controls the motor 22 by PWM (Pulse Width Modulation), and drives the motor 22 by changing the duty ratio of the pulse width according to the magnitude of the input signal.

Next, the functional configuration of the valve control device will be described. In the present embodiment, it is assumed that the ECU 31 functions as a valve control device. FIG. 5 is a functional block diagram showing a functional configuration of the valve control device. In the following description, the control target is limited to the opening degree of the cooling water valve 21.

  As shown in FIG. 5, the valve control device 5 includes an operation amount calculation unit 51, a determination unit 52, and a correction amount calculation unit 53 as functions. Note that these functions are realized by the cooperation of the CPU 311 and the memory 312 described above.

The operation amount calculation unit 51 is a target opening degree of the cooling water valve 21 calculated based on a target flow rate that is a flow rate of cooling water with respect to the target water jacket 12 in order to set the engine 11 to the target temperature. The operation amount for the motor 22 is calculated by PID control based on the target value as the target opening value and the actual measured value (current value) of the cooling water valve 21 detected by the position sensor 23 as feedback. In this embodiment, the movable range of the cooling water valve 21 is set to 190 °, for controlling the opening of the cooling water valve 21 and the resolution of the drive motor 22 and 240 at about 0.344 degree increments The control movable range of the cooling water valve 21 is about 82.6 ° . In addition, when the operation amount is increased in the positive direction, the cooling water valve 21 is controlled in the opening direction. In addition, the cooling water valve 21 is controlled at a predetermined sampling period.

  The determination unit 52 determines whether or not the coolant valve 21 has reached the target opening based on the control deviation and the change in the target opening.

  Further, the correction amount calculation unit 53 calculates the correction amount individually according to the operation direction until the cooling water valve 21 reaches the target opening degree. The correction amount calculation unit 53 refers to the operation amount one sample before calculated by the operation amount calculation unit 51, the control deviation one sample before, or the like in order to determine the operation direction until the target opening is reached. However, any means may be used to determine the operation direction. It is assumed that the correction amount calculated by the correction amount calculation unit 53 is output to the drive circuit 314 as an operation amount.

  Next, the determination process will be described. FIG. 6 is a flowchart showing the operation of the determination process. In this process, it is assumed that the operation amount has already been calculated by the operation amount calculation unit.

  As shown in FIG. 6, first, the determination unit 52 determines whether or not the control deviation of the previous sample is 0 (S101).

  When the control deviation of the previous sample is not 0 (S101, NO), the determination unit 52 determines whether the control deviation of the current sample is 0 (S102).

  When the control deviation in the current sample is 0 (S102, YES), the determination unit 52 determines whether the target opening degree has been changed (S103).

  When the target opening is not changed (S103, NO), the correction amount calculation unit 53 determines whether or not the operation direction until the coolant valve 21 reaches the target opening is the open direction (S104).

  When the operation direction is the open direction (S104, YES), the correction amount calculation unit 53 calculates the correction amount in the reverse direction, that is, the closing direction based on the operation amount one sample before (S105), and then determines The unit 52 waits for the next sample (S106), and again determines whether or not the control deviation of the previous sample is 0 (S101).

On the other hand, when the operation direction is the closing direction (S104, NO), the correction amount calculation unit 53 calculates the correction amount in the forward direction, that is, the closing direction based on the operation amount one sample before (S107), and thereafter The determination unit 52 waits for the next sample (S106), and again determines whether the control deviation of the previous sample is 0 (S101).

  When the target opening is changed in the determination in step S103 (S103, YES), the determination unit 52 waits for the next sample (S106), and again determines whether the control deviation of the previous sample is 0 or not. Is determined (S101).

  When the control deviation of the current sample is not 0 in the determination in step S102 (S102, NO), the determination unit 52 waits for the next sample (S106), and whether the control deviation of the previous sample is 0 again. It is determined whether or not (S101).

  If the control deviation of the previous sample is 0 in the determination in step S101 (S101, YES), the determination unit 52 waits for the next sample (S106), and whether the control deviation of the previous sample is 0 again. It is determined whether or not (S101).

  Next, the correction amount will be described. 7 to 11 are diagrams showing correction amount output patterns A to E, respectively. For the sake of convenience, the correction amount in FIGS. 7 to 11 is a forward correction amount with respect to the operation amount for comparison with the operation amount.

  Various patterns can be considered as the correction amount output by the correction amount calculation unit 53. The output pattern A shown in FIG. 7 is a pattern in which a correction amount less than that of the previous operation amount is output and attenuated. Further, the output pattern B shown in FIG. 8 is a pattern in which a correction amount higher than the previous operation amount is output and attenuated. Further, the output pattern shown in FIG. 9 is output at a predetermined cycle interval while attenuating a correction amount less than the previous operation amount. In addition, the output pattern shown in FIG. 10 outputs a correction amount, which is an absolute value less than the previous operation amount, while alternately switching a reverse direction and a forward direction with respect to the operation amount at a predetermined cycle interval. The absolute value is attenuated. Further, the output pattern shown in FIG. 11 is obtained by outputting a correction amount that is larger than the previous operation amount.

The correction amount calculation unit 53 calculates the correction amount based on such an output pattern, the output direction of the correction amount with respect to the operation direction of the cooling water valve 21 , the absolute value of the previous operation amount, and a predetermined coefficient multiplied by this. calculate. Incidentally, this output pattern, the output direction, the predetermined coefficients may be set in advance in advance according to the characteristics of the cooling water valve 21, also depending is appropriately changed to the parameter relating to the control of the cooling water valve 21 It doesn't matter. Further, it is conceivable that the predetermined coefficient is determined according to, for example, the resolution related to driving of the motor 22.

  As described above, when the cooling water valve 21 reaches the target opening, it is possible to deal with non-linear friction and slip stick by calculating a predetermined correction amount. Further, by calculating the correction amount individually according to the operation direction so far, it is possible to deal with the hysteresis having the directionality as described above. In addition, according to the valve control device 5 according to the present embodiment, it is possible to reduce overshoot or undershoot after reaching the target opening degree by these measures, and thus increase power consumption caused by these. This can prevent the power consumption associated with the control of the cooling water valve 21. Moreover, since overshoot or undershoot can be reduced, controllability with respect to the target opening degree is improved, and therefore controllability of the cooling water temperature can be improved. Further, by reducing overshoot or undershoot after reaching the target opening, the energization time for controlling the cooling water valve 21 is shortened, resulting in a gear, worm gear, etc. for transmitting the driving force of the motor 22 to the cooling water valve 21. The durability of the machine part can be improved.

  The present invention can be implemented in various other forms without departing from the gist or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is shown by the scope of claims, and is not restricted by the text of the specification. Moreover, all modifications, various improvements, substitutions and modifications belonging to the equivalent scope of the claims are all within the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 Engine cooling system, 5 Valve control apparatus, 11 Engine, 12 Water jacket, 13 Water pump, 21 Cooling water valve, 22 Motor, 23 Position sensor, 24 Water temperature sensor, 31 ECU, 41 Radiator, 42 Heater, 43 Throttle, 51 Operation amount calculation unit, 52 determination unit, 53 correction amount calculation unit, 81-84 gear, 85 worm, 86 worm wheel, 91 main flow channel pipe, 91a seal member, 92 sub flow channel pipe, 92a seal member, 93 bypass flow Road pipe, 311 CPU, 312 memory, 313 input / output interface, 314 drive circuit.

Claims (1)

A valve control device that controls a drive device that drives a valve in an opening direction or a closing direction,
An operation amount calculator that calculates an operation amount of the drive device based on a deviation between a target value of the valve opening and an actual value of the valve opening;
A determination unit for determining whether or not the opening of the valve has reached the target value;
When the determination unit determines that the opening degree of the valve has reached the target value, a correction amount that is an operation amount different from the operation amount is calculated based on the operation amount calculated by the operation amount calculation unit. A correction amount calculation unit for calculating,
The correction amount calculation unit calculates the correction amount in the open direction when the valve operating direction until the valve opening degree reaches the target value is the open direction, and when the operation direction is the closed direction A valve control device that calculates a correction amount in a closing direction.

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