JP2017004309A - Valve control device and valve control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve control device capable of reducing a deviation from a blind sector due to return of a valve without impairing controllability of a fluid temperature; and to provide a valve control method.SOLUTION: A valve control device comprises: an acquisition part 101 for acquiring a target opening which indicates a target position of a valve and an actual opening which indicates a current position of the valve; a calculation part 102 for calculating an opening deviation between the target opening and the actual opening; a determination part 103 for determining a code of the opening deviation; and an output part 104 for outputting to a drive part for driving the valve an opening deviation calculated as a control deviation for driving the valve, until the code becomes 0 or a negative code whenever the target opening is changed, and the acquisition of each opening, the calculation of the opening deviation, and the determination of the code are repeated.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a valve that controls a valve for adjusting a fluid such as a gas or a liquid, particularly a CCV (Coolant Control Valve) drive control that controls a rotary valve for adjusting a cooling water temperature of a water jacket of an internal combustion engine such as an automobile. The present invention relates to a control device and a valve control method.

  Conventionally, as a means for cooling an internal combustion engine such as an automobile, a water jacket is provided around the combustion chamber of the internal combustion engine, and heat is exchanged between the combustion chamber and the cooling water by supplying and circulating cooling water from the radiator to the water jacket. The method of performing is widely implemented. Further, it is preferable to adjust the temperature of the cooling water in accordance with the degree of load of the internal combustion engine from the viewpoint of improving the fuel efficiency of the automobile. As a method for performing this adjustment, a rotary valve ( Hereinafter, CCV drive control is known in which a valve is provided, and the valve is appropriately rotated by a DC motor to adjust the flow rate of cooling water from the radiator.

  Generally, in CCV drive control, the valve is configured to be driven via the DC motor, worm, and other gears. Although it is desirable that the DC motor always operates and the temperature of the cooling water is appropriately controlled, in such a case, there is a problem that the DC motor generates heat. In order to suppress the heat generation, by giving a certain degree of tolerance to the target temperature, a method for extending the operation stop time of the DC motor, specifically, to increase the operation stop time, that is, to increase the frequency of the stop It is known to provide a dead band in temperature.

  By the way, in general CCV drive control, the dead zone is provided in the target temperature by providing the dead zone in the target opening degree indicating the target position of the valve. That is, in the CCV drive control, the control deviation for driving the valve is calculated and calculated according to the dead zone with hysteresis. For example, the target opening and the actual opening indicating the current valve position are calculated. If the absolute value of the deviation is equal to or less than the threshold value A, it is determined that the actual opening is substantially located in the dead zone, and the control deviation is set to zero. Further, unless the absolute value of the subsequent deviation becomes equal to or higher than the threshold value B higher than the threshold value A, the control deviation is controlled as 0. With such control, the operation stop time of the DC motor is appropriately extended.

  As a technique related to the control, a target radiator flow rate (target Rd flow rate) is calculated with a PID (or PI) control amount based on a temperature difference between the cooling water flow paths on the cooling water outflow side and the inflow side, and this target Rd By making corrections to stabilize the flow rate, performing feedback control, etc., by controlling the valve linearly in the required state more realistically so that the cooling water reaches the required temperature, response delay etc. A technique for solving the problem is known (Patent Document 1).

Japanese Patent No. 3932227

  However, a seal material having elastic force such as EPDM (ethylene / propylene / diene rubber) is generally used for the seal of the valve, and twist caused by the elastic force of the seal member when the DC motor is stopped in the dead zone. Due to the return, the valve may be returned from the stop position in the return direction (for example, the closing direction when the valve has advanced in the opening direction). In the CCV drive control, it is important to control the minute opening. However, when the valve position deviates from the dead zone including the threshold value B due to such return from the stop position, it is necessary to redrive the DC motor. In addition to wasting extra power, there was a problem of causing deterioration of the DC motor. On the other hand, if the dead zone is excessively widened, the frequency of re-driving the DC motor is reduced, but there is a problem that the controllability of the cooling water temperature is deteriorated.

  The present invention has been made to solve the above-described problems, and provides a valve control device and a valve control method capable of reducing deviation from the dead zone caused by valve return without impairing controllability of fluid temperature. The purpose is to do.

  In order to solve the above-described problem, an aspect of the present invention provides an opening degree obtaining unit that obtains a target opening degree that indicates a target position of a valve and an actual opening degree that indicates a current position of the valve, and the target opening degree. A deviation calculation unit that calculates an opening deviation between the actual opening and a sign determination unit that determines a sign of the opening deviation, the target opening is changed, and the opening is acquired, Each time the calculation of the deviation and the determination of the sign are repeated, the drive for driving the valve until the sign becomes zero or the opposite sign, with the calculated opening degree deviation as the control deviation for driving the valve A deviation output unit for outputting to the unit.

  Further, according to one aspect of the present invention, a target opening that indicates a target position of a valve and an actual opening that indicates a current position of the valve are acquired, and an opening deviation between the target opening and the actual opening is obtained. And calculating the sign of the deviation, the target opening is changed, and each time the opening is obtained, the opening deviation is calculated, and the determination of the sign is repeated, the sign is zero or reversed. The calculated opening deviation is output as a control deviation for driving the valve to the drive unit that drives the valve until the sign of

  According to the present invention, the deviation from the dead zone due to the return of the valve can be reduced without impairing the controllability of the fluid temperature. The other effects of the present invention will be described in the section of the embodiment for carrying out the invention below.

It is a mimetic diagram showing an engine cooling system concerning this embodiment. It is a block diagram which shows the hardware constitutions of ECU. It is a functional block diagram which shows the function structure of ECU. It is a flowchart which shows the valve control process which concerns on this Embodiment. It is a flowchart which shows a state detection process. It is a flowchart which shows a transient state process. It is a flowchart which shows a valve opening process. It is a flowchart which shows a valve closing process. It is a flowchart which shows a zero state process. It is a flowchart which shows a steady state process.

  Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, the case where the present invention is applied to a control device for controlling a valve used in an engine cooling system for cooling an internal combustion engine (hereinafter referred to as an engine) such as an automobile with cooling water is taken as an example. Give an explanation. However, the present invention is not limited to this, and the present invention can be applied to any system that electronically controls the flow rate of liquid or gas using a valve.

  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, an engine cooling system 1 according to the present embodiment is provided around an engine 11 that is an internal combustion engine of a vehicle such as an automobile, and executes CCV drive control incorporating valve control processing described later. It is. Specifically, the engine cooling system 1 includes a water jacket 12, a water pump 13, a cooling water valve device 21, water temperature sensors 22a and 22b, an ECU (Engine Control Unit) 31, a radiator 41, a heater 42, a throttle 43, a main It mainly includes flow pipes 91a and 91b, a sub flow pipe 92, and a bypass flow pipe 93.

  The water jacket 12 is provided around the engine 11 and cools the engine 11 with cooling water inside the water jacket 12. The water jacket 12 is provided with a water pump 13, and cooling water flows into and out of the water pump 13. The cooling water that has flowed out of the water jacket 12 flows again into the water pump 13 via the bypass flow channel pipe 93 and also flows into the main flow channel pipe 91 a and / or the sub flow channel pipe 92. The main flow path pipe 91a allows the cooling water to flow into the radiator 41 for cooling the cooling water. The sub flow path pipe 92 includes a heater 42 for warming the passenger compartment and an inflow of exhaled air to the engine 11. Cooling water is allowed to flow into the throttle 43 for controlling the amount. The cooling water that has flowed into the radiator 41, the heater 42, and the throttle 43 via these pipes is allowed to flow into the water pump 13 again through the main flow path pipe 91b.

  The cooling water valve device 21 includes a rotatable rotary valve 211 for adjusting a cooling flow rate in the flow path, a DC motor 212 that is an actuator for rotationally driving the valve 211, And a position sensor 213 for detecting a circumferential position. The cooling water valve device 21 adjusts the flow of the cooling water into the main flow path pipe 91a and the sub flow path pipe 92 according to the opening degree of the valve 211. By this adjustment, the temperature control of the cooling water, The temperature control of the engine 11 is realized. Further, the position of the valve 211 with respect to the main flow path pipes 91 a and 91 b and the sub flow path pipe 92 is detected by detecting the position of the valve 211 in the circumferential direction by the position sensor 213. Further, water temperature sensors 22a and 22b provided in the cooling water valve device 21 and the radiator 41 respectively detect the temperature of the cooling water at each location.

  The ECU 31 is a microcontroller that controls various operations relating to the engine 11. In the present embodiment, the ECU 31 appropriately acquires data from the position sensor 213 and the water temperature sensors 22a and 22b, and the DC motor 212 is based on the acquired data. The following description will be given as a valve controller for controlling the operation.

  With each configuration of the engine cooling system 1 described above, the cooling water circulates through the main flow path pipe 91a, is cooled by the radiator 41, flows into the water jacket 12, and passes through the bypass flow path pipe 93. When it passes, it flows into the water jacket 12 again without being cooled. Therefore, the engine cooling system 1 switches the cooling water circulation path by adjusting the opening of the valve 211, and controls the cooling water inflow amount to the main flow path pipe 91a. The water can be cooled to a desired temperature, and the temperature control of the cooling water, that is, the temperature control of the engine 11 can be performed.

  Next, the hardware configuration of the ECU will be described. FIG. 2 is a block diagram illustrating a hardware configuration of the ECU.

  As shown in FIG. 2, the ECU 31 includes a CPU (Central Processing Unit) 311, a memory 312, and an input / output interface 313. The ECU 31 cooperates with the CPU 311, the memory 312, and the input / output interface 313 to perform processing related to the control of the valve 211. Specifically, information detected by various sensors such as the position sensor 213 and the water temperature sensors 22a and 22b is acquired via the input / output interface 313. Examples of the information to be acquired include the rotation speed of the engine 11, the manifold pressure, the cooling water temperature of the radiator 41, the target water temperature and the actual water temperature of the water jacket 12 as targets required from the host device.

  Based on these acquisition results, the ECU 31 calculates a required cooling water amount for achieving the required target water temperature, and indicates a target opening (opening) indicating the target position (opening) of the valve 211 that is the required cooling water amount. Calculate the degree. Since the calculation of the target opening is performed by a general method, details thereof are omitted in the present embodiment. In order to control the valve 211 so as to achieve this target opening, the operation amount of the DC motor 212 is calculated by a valve control process described later, and a signal corresponding to the operation amount of the DC motor 212 is driven via the input / output interface 313. Output to the circuit 23. The drive circuit 23 is a PWM circuit that performs PWM (Pulse Width Modulation) control on the DC motor 212, and drives the DC motor 212 by changing the duty ratio of the pulse width according to the magnitude of the input signal. is there.

  In the present embodiment, the movable range of the valve 211 is controlled by 190 °, the resolution related to driving the DC motor 212 is controlled by 240, and the opening of the valve 211 is controlled by 0.344 degrees. In addition, when the control deviation is increased in the positive direction, the valve 211 is controlled in the opening direction. The rotation control of the valve 211 performed in the valve control process described here is performed at a predetermined sampling period, and in the present embodiment, the sampling period is set to a 64 msec period.

  Briefly explaining the outline of the valve control process described above, the valve control process according to the present embodiment drives the valve 211 calculated at the current sample in the rotation control for rotating the valve 211 to the target opening degree. The sign of the deviation of the opening between the target opening and the actual opening, which is the basis of the control deviation (operation amount), is determined to be 0 (zero), that is, the actual opening of the current sample is the target opening. In this process, the valve 211 is rotated until the sign is reversed or the sign is reversed, that is, the actual opening of the current sample exceeds the target opening. Such valve control processing is realized by each function of the ECU 31.

  Next, the functional configuration of the ECU 31 will be described. FIG. 3 is a functional block diagram showing a functional configuration of the ECU. As shown in FIG. 3, the ECU 31 includes an acquisition unit 101, a calculation unit 102, a determination unit 103, and an output unit 104 as functions. Note that these functions are realized by the cooperation of hardware resources such as the CPU 311 and the memory 312 described above.

  The acquisition unit 101 acquires various types of information related to the valve control process. For example, the target opening degree of the current sample calculated or set in the upper process or the valve 211 of the current sample detected by the position sensor 23 is acquired. Get the actual opening. The calculation unit 102 calculates an opening deviation based on the actual opening and the target opening acquired by the acquisition unit 101.

  The determination unit 103 performs various determinations related to the valve control process. As various determinations, it is determined whether or not the absolute value of the opening deviation is equal to or less than a threshold value A that forms a dead zone A described later, or more than a threshold value B that forms a dead band B described later. And a determination as to whether or not the current state of the valve 211 satisfies a predetermined control condition for driving or stopping the valve 211, which will be described later. In the present embodiment, it is assumed that thresholds A and B are stored in a nonvolatile storage medium such as a ROM (Read Only Memory) (not shown). The output unit 104 outputs a control deviation for driving the valve 211 according to the determination process of the determination unit 103 to 0 or an opening degree deviation as a control deviation to the drive circuit 23.

  Next, details of the valve control processing by the ECU 31 will be described. FIG. 4 is a flowchart showing a valve control process according to the present embodiment. Note that the valve control process in the present embodiment is executed with the target opening degree set as a trigger, and outputs a control deviation for each sample. Further, the valve control process is continuously executed until the valve 211 is fully closed after a learning time after an ignition key switch (not shown) is turned off (so-called Key Off).

  First, as shown in FIG. 4, after the state detection process for detecting the state of the valve 211 of the current sample is executed (S1), the determination unit 103 signifies the opening degree deviation output in the state detection process. Is not 0 (zero), in other words, it is determined whether the sign is not plus or minus (S2). When the sign is other than 0 (S2, YES), a transient state process is executed to output the control deviation as 0 or an opening deviation value according to the state of the valve 211 (S3). When the sign is 0 (S2, NO), a steady state process is performed in which the control deviation is output as 0 and the valve 211 is in a steady state (S4). These transient state processing and steady state processing are appropriately switched depending on the state of the valve 211, and both are continuously executed until the key is turned off. Hereinafter, details of the above-described state detection processing, transient state processing, and steady state processing will be described.

  First, the details of the state detection process will be described. FIG. 5 is a flowchart showing the state detection process. As shown in FIG. 5, in the state detection process, the acquisition unit 101 first acquires the target opening and the actual opening in the current sample (S101). After acquisition, the determination unit 103 determines whether or not the acquired target opening degree has been changed (S102). This determination may be made based on, for example, whether or not the values of the current sample and the sample immediately before the current sample are different, and it is notified that the target opening has already been changed when the target opening is acquired ( It may be determined in such a manner that the ECU 31 has acquired in advance.

  When the target opening is changed (S102, YES), the determination unit 103 outputs refC = 1 as a determination result (S103), and the calculation unit 102 calculates the deviation between the acquired target opening and the actual opening. The calculation result is output as an opening degree deviation, and the sign of the opening degree deviation is output (S104). For example, when the target opening indicates a value lower than the actual opening, that is, an opening for rotating the valve 211 in the closing direction, the sign is − (minus), and the target opening is a value higher than the actual opening, that is, the valve. The sign is + (plus) when the opening degree that rotates 211 in the opening direction is indicated. In this embodiment, eSig = 1 is output when the sign is positive, eSig = −1 is output when the sign is negative, and eSig = 0 is output when the sign is zero. The output result here and the values of the subsequent output results are preferably stored in a storage area such as the memory 312 so that they can be read out appropriately. If the target opening is always changed, such as when the engine 11 is started, the determination process in step S102 may be omitted and refC = 1 may be output, and the determination process in step S102 may be omitted. On the other hand, when there is no change in the target opening degree (S102, NO), the determination unit 103 outputs refC = 0 as a determination result (S105), and proceeds to the calculation process of step S104.

  After outputting the opening degree deviation, the determination unit 103 determines whether or not the absolute value of the opening degree deviation is equal to or less than the threshold value A (S106). The threshold value A according to the present embodiment is a value for forming the dead zone A composed of the target opening degree ± A. This dead zone A is in the state where the valve 211 is controlled toward the target opening, and the actual opening is within the dead zone A, that is, the absolute value of the opening deviation is equal to or less than the threshold A. In other words, it is a range serving as a standard for determining that the desired temperature control is possible. When the opening degree deviation is less than or equal to the threshold value A (S106, YES), the determination unit 103 determines that the actual opening degree is in the dead zone A, outputs inRange = 1 (S107), and this flow is finished. Become. On the other hand, when the opening degree deviation is not equal to or less than the threshold value A (S106, NO), the determination unit 103 outputs inRange = 0 (S108).

  After outputting inRange = 0, the determination unit 103 determines whether or not the absolute value of the opening degree deviation is greater than or equal to the threshold value B (S109). The threshold value B according to the present embodiment is a value higher than the threshold value A, and is a value for forming the dead zone B composed of the target opening degree ± B. In this dead zone B, in the state where the valve 211 is controlled toward the target opening, if the actual opening is within the range of the dead zone B, the absolute value of the opening deviation is set higher than the threshold A. If it is less than the threshold value B, the desired temperature control is impossible, and this is a range that serves as a guideline for determining that the valve 211 needs to be driven to the target opening. On the other hand, in the dead zone B, when the actual opening degree deviates from the dead zone B due to the unintentional rotation of the valve 211 in a state where the actual opening degree is once determined to be in the dead zone A and the driving of the valve 211 is stopped, This is a guideline for re-driving 211 toward the target opening. In other words, once the actual opening is determined to be in the dead zone A and the rotation of the valve 211 is stopped, even if the actual opening deviates from the dead zone A due to the unintentional rotation of the valve 211, If so, the valve 211 is not re-driven.

  If the opening deviation is greater than or equal to the threshold value B (S109, YES), the determination unit 103 determines that the actual opening is not in the dead zone B, outputs outRange = 1 (S110), and the flow ends. Become. On the other hand, when the opening degree deviation is not greater than or equal to the threshold value B (S109, NO), the determination unit 103 determines that the actual opening degree is in the dead zone B but not in the dead zone A, and outputs outRange = 0 (S111). ), This flow ends.

  Through the above state detection processing, the ECU 31 determines whether the target opening is changed, the value of the opening deviation, the sign of the opening deviation, the position of the valve 211 (whether the actual opening is in the dead zones A and B, etc.) Can be recognized.

  Next, the details of the above-described transient state processing executed based on these pieces of information will be described. FIG. 6 is a flowchart showing the control deviation output process. As shown in FIG. 6, in the transient state process, first, the determination unit 103 determines whether eSig indicating the code output in the state detection process of the current sample is 1, −1, or 0 (S201). . Here, when eSig = 1 (S201, 1), valve opening processing is executed (S202), and when eSig = −1 (S201, -1), valve closing processing is executed (S203). ), If eSig = 0 (S201, 0), zero state processing described later is executed (S204). The details of the valve opening process, the valve closing process, and the zero state process will be sequentially described below.

  First, the valve opening process will be described with reference to FIG. FIG. 7 is a flowchart showing the valve opening process. As shown in this figure, since the valve opening process is eSig = 1, it is considered that the actual opening is lower than the target opening and the valve 211 has not reached the target opening. The opening deviation calculated in the state detection process at the time of the current sample is set as a control deviation (S301), and this is output to the drive circuit 23 (S302). The drive circuit 23 that has received the control deviation drives the DC motor 212 based on the control deviation to rotate the valve 211 in the opening direction. After the control deviation is output, the process waits until the current sample is completed, that is, until 64 msec elapses from the start of the current sample (S303). Here, in the present embodiment, the sample transition time, that is, the time when the state detection process is executed is set as the sample start time. However, the present invention is not limited to this. For example, the time point when the result of the state detection process is acquired may be set as the sample start time point. After the standby process, the process proceeds to the next sample, and the state detection process similar to step S1 described above is executed again (S304). Thereafter, the determination unit 103 determines that the process result of the current sample state detection process is a predetermined first value. It is determined whether or not the control condition is satisfied (S305).

  The first control condition in the present embodiment is that refC = 0 and eSig = 0, or refC = 0, inRange = 1, and eSig = −1. In other words, the first control condition is that the code indicated in the code determination result is a code opposite to the code determination result at the time of the initial sample or the code determination result at the immediately preceding sample, or is 0. In addition, the absolute value of the opening degree deviation is not more than the threshold value A, and the target opening degree is not changed. That is, satisfying the first control condition indicates that the actual opening has reached the target opening or has exceeded the dead zone A range.

  Therefore, when it is determined that the first control condition is satisfied (S305, YES), the process proceeds to the steady state process of step S4 shown in FIG. On the other hand, when it is determined that the first control condition is not satisfied (S305, NO), the determination unit 103 determines whether or not the processing result of the current sample state detection process satisfies a predetermined second control condition. (S306).

  The second control condition in the present embodiment is that eSig = −1 or refC = 1. That is, when the first control condition is not satisfied and the second control condition is satisfied, the target opening degree may be changed and the process may be performed again, or the valve 211 may be rotated too much to exceed the dead zone A. is assumed. On the other hand, in the case where none of the control conditions is satisfied, it is assumed that the valve 211 has not yet reached the target opening. Therefore, when it is determined that the second control condition is satisfied (S306, YES), the process proceeds to the transient state process of step S3 shown in FIG. 4, and it is determined that the second control condition is not satisfied. In this case (S306, NO), the process of setting the opening deviation in step S301 as the control deviation is executed again.

  As described above, by determining the opening based on the first control condition and the second control condition, even if the actual opening is within the dead zone A range, if the target opening is not reached, the valve 211 Can continue to rotate in the opening direction. Thereby, even if the return of the valve 211 occurs, it is possible to increase the possibility that the valve 211 stays on one side in the dead zone A, that is, in the closed direction side range less than the target opening in the dead zone A, and in the dead zones A and B. Deviations from can be reduced.

  Next, the valve closing process will be described with reference to FIG. FIG. 8 is a flowchart showing the valve closing process. In the valve closing process, since the sign eSig = -1 at the time of the transition, it is considered that the valve 211 has not reached the target opening degree as in the valve opening process. Therefore, the valve 211 is rotated. However, the rotation direction is the closing direction as opposed to the valve opening process. Therefore, the valve closing process is the same as the valve opening process except that the rotation direction of the valve 211 is the closing direction and the determination processes in steps S405 and S406 shown in FIG. Description of processes other than the process is omitted.

  As shown in FIG. 8, after the state detection process of step S304 is performed, the determination unit 103 determines whether or not the processing result of the current sample state detection process satisfies a predetermined third control condition ( S405). The third control condition in the present embodiment is that refC = 0 and eSig = 0, or refC = 0, inRange = 1, and eSig = 1. In other words, in the third control condition, as in the first control condition, the code shown in the code determination result is the reverse of the code determination result at the initial sample or the code determination result at the immediately preceding sample. Or the absolute value of the opening deviation is not more than the threshold value A, and the target opening is not changed. Therefore, satisfying the third control condition means that, as in the case of satisfying the first control condition, the actual opening has reached the target opening or has exceeded the dead zone A range. Show.

  Therefore, when it is determined that the third control condition is satisfied (S405, YES), the routine proceeds to the steady state process of step S4 shown in FIG. On the other hand, when it is determined that the third control condition is not satisfied (S405, NO), the determination unit 103 determines whether or not the processing result of the current sample state detection process satisfies a predetermined fourth control condition. (S406).

  The fourth control condition in the present embodiment is that eSig = 1 or refC = 1. That is, when the third control condition is not satisfied and the fourth control condition is satisfied, as in the case where the first control condition is not satisfied and the second control condition is satisfied, the target opening is changed and the process is performed again. It is assumed that the valve 211 has rotated too much to exceed the dead zone A. On the other hand, a case where none of the control conditions is satisfied may be that the valve 211 has not yet reached the target opening. Therefore, when it is determined that the fourth control condition is satisfied (S406, YES), the process proceeds to the transient state process of step S3 shown in FIG. 4 and it is determined that the fourth control condition is not satisfied. In this case (S406, NO), the process of setting the opening deviation in step S301 as the control deviation is executed again.

  As described above, by determining the opening based on the third control condition and the fourth control condition, even if the actual opening is within the dead zone A range, if the target opening is not reached, the valve 211 Can continue to be driven in the closing direction. Thereby, even if the return of the valve 211 occurs, it is possible to increase the possibility that the valve 211 stays on one side in the dead zone A, that is, in the open direction side range exceeding the target opening degree in the dead zone A. Deviations from the dead zones A and B can be reduced.

  Next, the zero state process will be described with reference to FIG. FIG. 9 is a flowchart showing the zero state process. As shown in this figure, since the zero state process is the sign eSig = 0, it is assumed that the valve 211 is in the target opening degree. Therefore, first, the output unit 104 sets the control deviation = 0 (S501). This is output to the drive circuit 23 (S502). The drive circuit 23 that has received a control deviation of 0 stops driving the DC motor 212 and stops the valve 211. Since the processes in steps S303 and S304 after the output of the control deviation are the same as the valve opening process and the valve closing process described above, the description thereof is omitted here. After the state detection process is performed again, the determination unit 103 determines whether the processing result of the current sample state detection process satisfies a predetermined fifth control condition (S505).

  The fifth control condition in the present embodiment is that refC = 0 and inRange = 1 or eSig = 0. That is, there is no change in the target opening, and the actual opening is in the dead zone A, or the actual opening is the target opening. Therefore, when it is determined that the fifth control condition is satisfied (S505, YES), there is no need to rotate the valve 211, and the routine proceeds to the steady state process of step S4 shown in FIG. On the other hand, if it is determined that the fifth control condition is not satisfied (S505, NO), since eSig = 0 is not always (ie, eSig = 1 or −1) or refC = 1, the unintentional valve 211 It is assumed that the sign is no longer 0 due to the rotation of or that the target opening has changed. Therefore, in this case, the process proceeds to the transient state process of step S3 shown in FIG.

  Next, details of the above-described steady state processing will be described. FIG. 10 is a flowchart showing steady state processing. In the steady state process, the control deviation = 0 is continuously output until a predetermined control condition is satisfied as a steady state. Therefore, since it is the same as the above-described zero state process except for the determination process of step S605 shown in FIG. 10, the description of the processes other than the determination process here is omitted. As shown in FIG. 10, after the state detection process is executed again, the determination unit 103 determines whether or not the processing result of the current sample state detection process satisfies a predetermined sixth control condition (S605). ).

  The sixth control condition in the present embodiment is that refC = 1 or outRange = 1. Therefore, when it is determined that the sixth control condition is satisfied (S605, YES), the target opening is changed or the actual opening is the dead zone of the current target opening due to the unintentional rotation of the valve 211. Since it is assumed that the vehicle has deviated from B, the process proceeds to the transient state process of step S3 shown in FIG. On the other hand, when it is determined that the sixth control condition is not satisfied (S605, NO), the process of setting the control deviation to 0 in step S501 is executed again. Note that, after the determination processing in step S605, the opening degree deviation may be set as a control deviation, and after this is output to the drive circuit 23, the transition to the transient state processing in step S3 may be performed. In addition, even if refC = 1, the target opening may be in the dead zone A. Therefore, the sixth control condition may be inRange = 0 when refC = 1.

  According to the present embodiment described above, the valve 211 is driven to rotate until the target opening degree or the target opening degree is exceeded, that is, the entry of the actual opening degree into the dead zone A is determined only on one side of the dead zone A. In comparison with a control method in which the control deviation is zero when the absolute value of the opening deviation becomes equal to or less than the threshold A, that is, when the actual opening of the valve 211 reaches the dead zone A, Deviations from the dead zones A and B due to the return of the valve 211 can be reduced. Therefore, since the frequency of re-driving the DC motor 212 can be reduced, it is possible to extend the operation stop time of the DC motor 212, thereby suppressing power consumption, deterioration of the DC motor 212, and the like. Thereby, it is possible to use an inexpensive motor control electronic component whose specification is reduced, and it is possible to realize cost reduction.

  When the target opening is exceeded and the dead zone A remains within the dead zone A, the actual opening approaches the target opening by the return of the valve 211. Therefore, since the control deviation can be reduced as compared with the above control method, the dead zones A and B themselves can be set narrow, and the controllability of the cooling water can be further improved.

  Note that the flowchart described in the present embodiment is an example, and any control can be used as long as the valve 211 can be controlled to rotate within the target opening or dead zone A until the target opening is exceeded. It goes without saying that the processing steps may be changed and replaced, and the control conditions may be changed. For example, the control deviation may be controlled to be zero at the stage where the sign of the control deviation is reversed except for the determination of inRange and outRange. In this case, after determining that the control deviation is 0 and moving to the next sample, the determination of inRange and outRange (or determination using dead zones A and B) is incorporated to determine whether or not the valve 211 has rotated unintentionally. Also good. Further, even if refC = 1 at the time of various determinations, if inRange = 1, there is a possibility that the target opening is within the dead zone A. Therefore, if inRange = 1, refC may be regarded as 0. Good.

  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.

  The valve control device described in the claims corresponds to, for example, the ECU 31 in the above-described embodiment. The opening degree acquisition unit corresponds to, for example, the acquisition unit 101, and the deviation calculation unit corresponds to, for example, the calculation unit 102. The code determination unit, the deviation determination unit, and the state determination unit correspond to the determination unit 103, for example, and the deviation output unit corresponds to the output unit 104, for example. The drive unit corresponds to the drive circuit 23, for example.

  DESCRIPTION OF SYMBOLS 1 Engine cooling system, 23 Drive circuit, 31 ECU, 101 Acquisition part, 102 Calculation part, 103 Determination part, 104 Output part, 211 Valve | bulb.

Claims (4)

An opening degree obtaining unit for obtaining a target opening degree indicating a target position of the valve and an actual opening degree indicating the current position of the valve;
A deviation calculating unit for calculating an opening deviation between the target opening and the actual opening;
A sign determination unit for determining a sign of the opening deviation;
Every time the target opening is changed and the acquisition of each opening, the calculation of the opening deviation, and the determination of the sign are repeated, the opening calculated until the sign becomes zero or an opposite sign A deviation output unit that outputs a deviation as a control deviation for driving the valve to a drive unit that drives the valve;
A valve control device comprising: A deviation determination unit for determining whether or not the absolute value of the opening degree deviation is within a predetermined range;
The deviation output unit outputs the control deviation, and after obtaining each opening, calculating the opening deviation, determining the sign, and determining the absolute value, based on the determination result of the sign A state determination unit for determining whether the current valve state satisfies a predetermined condition for driving or stopping the valve;
The valve control device according to claim 1, further comprising:   The state determination unit determines whether the code indicated by the determination result of the code is a code opposite to the determination result of the initial code, the determination result of the previous code, or 0. , It is determined that the code indicated in the determination result of the code is a code opposite to the determination result of the initial code or the determination result of the previous code, or 0, and the absolute value is within a predetermined range. 3. The valve control device according to claim 2, wherein when the acquired target opening is not changed, the control deviation is output as 0 in order to stop the valve. Obtaining a target opening indicating the target position of the valve and an actual opening indicating the current position of the valve;
Calculating an opening deviation between the target opening and the actual opening;
Determine the sign of the opening deviation,
Every time the target opening is changed and the acquisition of each opening, the calculation of the opening deviation, and the determination of the sign are repeated, the opening calculated until the sign becomes zero or an opposite sign A valve control method for outputting a deviation as a control deviation for driving the valve to a drive unit for driving the valve.

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