JP6737570B2 - Valve control device - Google Patents

Description

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

Conventionally, as a means for cooling an internal combustion engine of an automobile or the like, a water jacket is provided around the combustion chamber of the internal combustion engine, and cooling water is supplied from the radiator to the water jacket to circulate the heat exchange between the combustion chamber and the cooling water. The method of performing is widely practiced. Further, it is preferable to adjust the temperature of the cooling water according to the degree of load of the internal combustion engine from the viewpoint of improving the fuel efficiency of the automobile, and as a method of 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, a valve is configured to be driven via the DC motor, worm, and other gears. It is desirable that the DC motor always operates and the temperature of the cooling water be appropriately controlled, but in such a case, there is a problem that heat generation of the DC motor occurs. In order to suppress the heat generation, a method of extending the operation stop time of the DC motor by allowing the target temperature to some extent, specifically, to increase the operation stop time, that is, to increase the stop frequency, the target It is known to provide a dead zone for temperature.

By the way, in general CCV drive control, a dead zone is provided at the target temperature by providing a dead zone at the target opening 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, and, for example, the target opening and the actual opening indicating the current valve position are calculated. When the absolute value of the deviation is equal to or smaller than the threshold value A, it is determined that the actual opening is substantially within the dead zone, and the control deviation is set to zero. Further, unless the absolute value of the subsequent deviation is equal to or higher than the threshold value B higher than the threshold value A, the control deviation is set to 0. By such control, the operation stop time of the DC motor is properly extended.

As a technique related to the control, a target radiator flow rate (target Rd flow rate) is calculated by a PID (or PI) control amount based on the temperature difference in the cooling water channels on the outflow side and the inflow side of the cooling water, and this target Rd is calculated. Response is delayed by linearly controlling the valve so that the cooling water reaches the required temperature, such as by performing corrections to stabilize the flow rate and performing feedback control. 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 sealing the valve, and twisting due to the elastic force of the seal member when the DC motor is stopped in the dead zone is used. The return may cause the valve to return from the stop position in the return direction (eg, the closing direction if the valve was advancing in the opening direction). In CCV drive control, it is important to control a minute opening. However, when the valve position deviates from the dead zone defined by the threshold value B due to such a return from the stop position, it is necessary to redrive the DC motor. However, there is a problem that not only the extra power is wasted but also the deterioration of the DC motor is caused. On the other hand, if the dead zone is excessively widened, the frequency of re-driving the DC motor decreases, but the controllability of the cooling water temperature deteriorates.

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

In order to solve the above-described problem, one aspect of the present invention is an opening degree acquisition unit that acquires 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. And a deviation calculation unit that calculates an opening deviation between the actual opening, a code determination unit that determines the sign of the opening deviation, the target opening is changed, the acquisition of each opening, the opening Each time the calculation of the deviation and the determination of the sign are repeated, the calculated opening deviation is used as a control deviation for driving the valve until the sign becomes zero or an opposite sign. And a deviation output section for outputting to the section.

Further, according to one aspect of the present invention, a target opening indicating a target position of the valve and an actual opening indicating a current position of the valve are acquired, and an opening deviation between the target opening and the actual opening is calculated. The sign of the deviation is calculated, the target opening is changed, and each time the opening is acquired, the deviation of the opening is calculated, and the judgment of the sign is repeated, the sign is zero or reverse. 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 “1”.

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. Other effects of the present invention will also be described in the section of the following modes for carrying out the invention.

It is a schematic diagram which shows the engine cooling system which concerns on this Embodiment. It is a block diagram which shows the hardware constitutions of ECU. It is a functional block diagram which shows the functional structure of ECU. It is a flow chart which shows valve control processing concerning 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 flow chart which shows valve closing processing. It is a flowchart which shows a zero state process. It is a flowchart which shows a steady state process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, the case where the present invention is applied to a control device that controls a valve used in an engine cooling system that cools an internal combustion engine (hereinafter referred to as an engine) of an automobile or the like with cooling water is taken as an example. I will explain. 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, which is an internal combustion engine of a vehicle such as an automobile, and executes CCV drive control incorporating valve control processing described later. 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 body. The flow path pipes 91a and 91b, the sub flow path pipe 92, and the bypass flow path pipe 93 are mainly provided.

The water jacket 12 is provided around the engine 11 and cools the engine 11 by cooling water inside the engine. The water jacket 12 is provided with a water pump 13, and the water pump 13 causes the cooling water to flow into and out of the cooling water. The cooling water flowing out of the water jacket 12 flows into the water pump 13 again via the bypass flow path pipe 93, and also flows into the main flow path pipe 91 a and/or the sub flow path pipe 92. The main flow path pipe 91a is for allowing the cooling water to flow into the radiator 41 for cooling the cooling water, and the sub-flow path pipe 92 is for the heater 42 for warming the interior of the vehicle and the inflow of exhaled air into the engine 11. The cooling water is made 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 each of these pipes is allowed to flow into the water pump 13 again through each of the main flow path pipes 91b.

The cooling water valve device 21 includes a rotatable rotary valve 211 for adjusting the flow rate of cooling in its flow path, a DC motor 212 which is an actuator for rotationally driving the valve 211, and a valve 211. It has a position sensor 213 for detecting a position in the circumferential direction. The cooling water valve device 21 adjusts the inflow of the cooling water into the main flow path pipe 91a and the sub flow path pipe 92 by the opening degree of the valve 211, and by this adjustment, the temperature control of the cooling water and the extension of the cooling water. The temperature control of the engine 11 is realized. Further, the position sensor 213 detects the circumferential position of the valve 211 to detect the opening degree of the valve 211 with respect to the main flow path pipes 91a and 91b and the sub flow path pipe 92. The 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 related to the engine 11, and in the present embodiment, appropriately acquires data from the position sensor 213 and the water temperature sensors 22a and 22b, and based on the acquired data, the DC motor 212. The following description will be given as a valve controller for controlling the operation.

With the components of the engine cooling system 1 described above, the cooling water is cooled by the radiator 41 by circulating through the main flow path pipe 91a, flows into the water jacket 12, and bypasses the bypass flow path pipe 93. When passing through, it flows into the water jacket 12 again without being cooled. Therefore, the engine cooling system 1 switches such a circulation path of the cooling water by adjusting the opening degree of the valve 211, and controls the inflow amount of the cooling water into the main flow path pipe 91a. The water can be cooled to a desired temperature, and the temperature of the cooling water, and thus the temperature of the engine 11, can be controlled.

Next, the hardware configuration of the ECU will be described. FIG. 2 is a block diagram showing the 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, through the input/output interface 313, the information detected by various sensors such as the position sensor 213 and the water temperature sensors 22a and 22b is acquired. The information to be acquired includes the number of revolutions of the engine 11, the manifold pressure, the cooling water temperature of the radiator 41, the target water temperature of the water jacket 12 as a target required by the host device, the actual water temperature, and the like.

The ECU 31 calculates the required amount of cooling water for achieving the required target water temperature based on these acquisition results, and sets the target opening (opening) indicating the target position (opening degree) of the valve 211 that achieves this required amount of cooling water. Calculate the degree. Since the calculation of the target opening degree is performed by a general method, the details thereof will be omitted in the present embodiment. In order to control the valve 211 to reach 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 controls the DC motor 212 by PWM (Pulse Width Modulation), 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 this embodiment, the movable range of the valve 211 is controlled at 190°, the resolution for driving the DC motor 212 is controlled at 240, and the opening degree of the valve 211 is controlled at 0.344° unit. Further, 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 cycle, and in the present embodiment, the sampling cycle is set to 64 msec.

To briefly explain 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. The sign of the opening deviation between the target opening and the actual opening, which is the basis of the control deviation (manipulation amount) for determining, is determined, and the sign is 0 (zero), that is, the actual opening of the current sample is the target opening. This is a process of rotating the valve 211 until the degree of rotation is reached 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 the hardware resources such as the CPU 311 and the memory 312 described above.

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

The determination unit 103 makes various determinations regarding the valve control process. As various determinations, it is determined whether the absolute value of the opening deviation is less than or equal to a threshold A forming a dead zone A described below, or more than a threshold B forming a dead zone B described below, the opening deviation. And the determination of whether 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, the threshold values A and B are assumed to be stored in a nonvolatile storage medium such as a ROM (Read Only Memory) not shown. The output unit 104 outputs the control deviation for driving the valve 211 to 0 according to the determination processing of the determination unit 103, or outputs the opening deviation to the drive circuit 23 as the control deviation.

Next, details of the valve control processing by the ECU 31 will be described. FIG. 4 is a flowchart showing the valve control process according to this embodiment. The valve control process according to the present embodiment is executed with the setting of the target opening as a trigger, and the control deviation is output for each sample. In addition, the valve control process is continuously executed until the valve 211 is fully closed after a learning time after the 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 determines the sign of the opening deviation output in the state detection process. Is other than 0 (zero), in other words, whether the sign is not plus or minus (S2). When the code is other than 0 (S2, YES), the transient state process of outputting the control deviation as 0 or the value of the opening deviation is executed according to the state of the valve 211 (S3), and the code is not 0, that is, When the code is 0 (S2, NO), the steady state process for outputting the control deviation as 0 and bringing the valve 211 into the steady state is executed (S4). The transient state process and the steady state process are appropriately switched according to 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 the acquisition, the determination unit 103 determines whether the acquired target opening has been changed (S102). This determination may be made by, for example, whether or not the values of the current sample and the sample immediately before the current sample are different, and when the target opening is acquired, it is notified that the target opening has already been changed ( Alternatively, the determination may be made in advance by the ECU 31).

When the target opening is changed (S102, YES), the determination unit 103 outputs refC=1 as the determination result (S103), and the calculation unit 102 calculates the deviation between the acquired target opening and the actual opening. The calculation is performed and the calculation result is output as the opening deviation, and the sign of the opening deviation is output (S104). For example, when the target opening is a value lower than the actual opening, that is, the 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. When indicating the opening degree for rotating the 211 in the opening direction, the sign is + (plus). In the present embodiment, when the sign is plus, eSig=1 is output, when the sign is minus, eSig=-1 is output, and when the sign is zero, eSig=0 is output. It is preferable that the values of the output result here and the subsequent output results are stored in a storage area such as the memory 312 so that they can be read appropriately. When the target opening is always changed, such as when the engine 11 is started, the determination process of step S102 may be omitted, refC=1 may be output, and the determination process of step S102 may be omitted. On the other hand, when the target opening has not been changed (S102, NO), the determination unit 103 outputs refC=0 as the determination result (S105), and proceeds to the calculation process of step S104.

After outputting the opening deviation, the determination unit 103 determines whether the absolute value of the opening 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 having the target opening degree ±A. The dead zone A should be such that the actual opening is within the range of the dead zone A while the valve 211 is controlled toward the target opening, that is, the absolute value of the opening deviation is equal to or less than the threshold value A. For example, it is a range that is a standard for determining that desired temperature control is possible. When the opening deviation is less than or equal to the threshold value A (S106, YES), the determination unit 103 determines that the actual opening is within the dead zone A, outputs inRange=1 (S107), and the present flow ends. 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 the absolute value of the opening deviation is equal to or greater than 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 having the target opening degree ±B. The dead zone B is set so that the actual opening is within the range of the dead zone B while the valve 211 is controlled toward the target opening, that is, the absolute value of the opening deviation is higher than the threshold value A. If the threshold value is equal to or lower than the threshold value B, the desired temperature control is impossible, and the range is a reference range 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 is once determined to be within the dead zone A and the drive of the valve 211 is stopped, the actual opening degree deviates from the dead zone B due to unintentional rotation of the valve 211. This serves as a guide for re-driving 211 toward the target opening degree again. In other words, once the actual opening is determined to be within 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 unintentional rotation of the valve 211, the dead zone B is If so, the valve 211 is not re-driven.

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

Through the above state detection processing, the ECU 31 determines whether or not 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 within the dead zones A and B, etc.). Can be recognized.

Next, the details of the above-described transient state process 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, the determination unit 103 first determines whether eSig indicating the code output in the state detection process of the current sample is 1, -1, or 0 (S201). .. If eSig=1 here (S201, 1), the valve opening process is executed (S202), and if eSig=-1 (S201, -1), the valve closing process is executed (S203). ), if eSig=0 (S201, 0), the zero state process described later is executed (S204). 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 the figure, in the valve opening process, since the symbol eSig=1, it is considered that the actual opening is lower than the target opening and the valve 211 does not reach the target opening. The unit 104 sets the opening deviation calculated in the state detection process at the current sample as a control deviation (S301), and outputs it 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 has elapsed 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 defined as the sample start time. Note that the present invention is not limited to this, and the sampling start time may be the time when the result of the state detection processing is acquired, for example. After the standby process, the process moves to the next sample, and the state detection process similar to step S1 described above is executed again (S304), and then the determination unit 103 determines that the process result of the state detection process of the current sample is the first predetermined one. It is determined whether the control conditions are satisfied (S305).

The first control condition in the present embodiment is that refC=0 and eSig=0, or refC=0 and inRange=1 and eSig=-1. In other words, the first control condition is that the sign shown in the sign judgment result is the sign opposite to the sign judgment result of the initial sample or the sign judgment result of the immediately preceding sample, or 0. In addition, the absolute value of the opening deviation is equal to or less than the threshold value A, and the target opening is not changed. That is, satisfying the first control condition indicates that the actual opening has reached the target opening or has exceeded the target opening within 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 the processing result of the state detection process of the current sample satisfies the predetermined second control condition. Yes (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 may be changed and the process may be redone, or the valve 211 may be rotated too much and the dead zone A may be exceeded. is assumed. On the other hand, if 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 using the opening degree deviation of 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 be continuously rotated in the opening direction. As a result, even if the valve 211 returns, it is possible to increase the possibility that the valve 211 remains on one side in the dead zone A, that is, within the dead zone A in the closing direction side range that is less than the target opening degree. It is possible to reduce the deviation from.

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 like the valve opening process. Therefore, the process of rotating the valve 211 is performed. However, the turning direction is the closing direction, which is the opposite of the valve opening process. Therefore, the valve closing process is the same as the valve opening process except that the turning direction of the valve 211 is the closing direction and the determination processes of steps S405 and S406 shown in FIG. Descriptions of processes other than the processes are omitted.

As illustrated 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 state detection process of the current sample satisfies the predetermined third control condition ( S405). The third control condition in the present embodiment is that refC=0 and eSig=0, or refC=0 and inRange=1 and eSig=1. In other words, the third control condition is the same as the first control condition, and the sign shown in the sign judgment result is the sign opposite to the sign judgment result of the initial sample or the sign judgment result of the immediately preceding sample. , Or 0, and the absolute value of the opening deviation is less than or equal to the threshold value A, and there is no change in the target opening. Therefore, to satisfy the third control condition means that the actual opening has reached the target opening or exceeds the target opening within the dead zone A as in the case where the first control condition is satisfied. Showing.

Therefore, when it is determined that the third control condition is satisfied (S405, 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 third control condition is not satisfied (S405, NO), the determination unit 103 determines whether the processing result of the state detection process of the current sample satisfies the predetermined fourth control condition. Yes (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 and has exceeded the dead zone A. On the other hand, if none of the control conditions is satisfied, it may be considered 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 using the opening degree deviation as the control deviation in step S301 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 be continuously driven in the closing direction. As a result, even if the valve 211 returns, it is possible to increase the possibility that the valve 211 stays on one side in the dead zone A, that is, within the opening direction side range exceeding the target opening in the dead zone A, and similar to the valve opening process. , It is possible to reduce the deviation from the dead zones A and B.

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 sign eSig=0 in the zero state process, it is assumed that the valve 211 has reached the target opening degree. Therefore, the output unit 104 first sets the control deviation=0 (S501). ), and outputs it to the drive circuit 23 (S502). The drive circuit 23 that has received the control deviation of the value of 0 stops the drive of the DC motor 212 and stops the valve 211. Since each processing of steps S303 and S304 after the output of the control deviation is the same as the above-described valve opening processing and valve closing processing, the description thereof is omitted here. After the state detection process is executed again, the determination unit 103 determines whether the processing result of the state detection process of the current sample satisfies the 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, the target opening does not change and the actual opening is within 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 therefore the routine proceeds to the steady state process of step S4 shown in FIG. On the other hand, when it is determined that the fifth control condition is not satisfied (S505, NO), eSig=0 other than 0 (that is, eSig=1 or −1) or refC=1, so the undesired valve 211 It is assumed that the sign has become non-zero due to the rotation of or the target opening has changed. Therefore, in this case, the process proceeds to the transient state process of step S3 shown in FIG.

Next, the details of the above-mentioned steady state process will be described. FIG. 10 is a flowchart showing the steady state process. The steady state process is a process of continuously outputting control deviation=0 until a predetermined control condition is satisfied as a steady state. Therefore, except for the determination processing of step S605 shown in FIG. 10, the processing is the same as the above-mentioned zero state processing, and therefore the description of the processing other than the determination processing is omitted here. As illustrated in FIG. 10, after the state detection process is executed again, the determination unit 103 determines whether the processing result of the state detection process of the current sample satisfies the 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 unintentional rotation of the valve 211. Since it is assumed that the deviation from B has occurred, 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. After the determination processing of step S605, the opening deviation may be set as the control deviation, which may be output to the drive circuit 23, and then the transition state processing of step S3 may be performed. Further, even if refC=1, the target opening may be in the dead zone A, so the sixth control condition may be inRange=0 when refC=1.

According to the present embodiment described above, the valve 211 is rotationally driven until it reaches the target opening or exceeds the target opening, that is, the entry of the actual opening into the dead zone A is determined only on one side of the dead zone A. By doing so, as compared with the control method in which the control deviation is set to 0 when the absolute value of the opening deviation becomes equal to or less than the threshold value A, that is, when the actual opening of the valve 211 reaches the dead zone A, It is possible to reduce the deviation from the dead zones A and B due to the return of the valve 211. Therefore, the frequency of re-driving the DC motor 212 can be reduced, so that the operation stop time of the DC motor 212 can be extended, which in turn can suppress power consumption and deterioration of the DC motor 212. As a result, it is possible to use an inexpensive motor control electronic component whose specifications have been reduced, and it is possible to realize cost reduction.

If the dead zone A is exceeded by exceeding the target opening, the valve 211 returns to bring the actual opening closer to the target opening. Therefore, the control deviation can be reduced as compared with the above control method, so that the dead zones A and B themselves can be set narrower, and the controllability of the cooling water can be further improved.

It should be noted that the flowchart described in the present embodiment is an example, and any control can be performed as long as it can control the valve 211 to rotate within the range of 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 set to 0 when the sign of the control deviation is reversed except for the determination of inRange and outRange. In this case, after the control deviation is set to 0 and the process shifts to the next sample, the determination of inRange or outRange (or the determination using the dead zones A and B) is incorporated to determine whether or not the valve 211 is unintentionally rotated. Good. Even if refC=1 at various determinations, the target opening may be within the dead zone A if inRange=1. Therefore, if inRange=1, refC may be regarded as 0. Good.

The present invention may be embodied in various forms without departing from the gist or the main features thereof. Therefore, the above-described embodiment is merely an example in all points and should not be limitedly interpreted. The scope of the present invention is defined by the scope of the claims, and is not bound by the text of the specification. Further, all modifications, various improvements, substitutions and modifications within the scope of equivalents of the claims are 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. Further, 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 sign determination unit, the deviation determination unit, and the state determination unit correspond to, for example, the determination unit 103, and the deviation output unit corresponds to, for example, the output unit 104. The drive unit corresponds to, for example, the drive circuit 23.

1 engine cooling system, 23 drive circuit, 31 ECU, 101 acquisition part, 102 calculation part, 103 determination part, 104 output part, 211 valve.

Claims (2)

An opening degree acquisition unit that acquires a target opening degree that indicates the target position of the valve and an actual opening degree that indicates the current position of the valve,
A deviation calculation unit that calculates an opening deviation between the target opening and the actual opening,
A code determination unit that determines the code of the opening deviation,
Each time the target opening is changed, the acquisition of each opening, the calculation of the opening deviation, and the determination of the sign are repeated, the calculated opening until the sign becomes zero or an opposite sign. A deviation output unit that outputs the deviation to a drive unit that drives the valve as a control deviation for driving the valve;
A deviation determination unit that determines whether the absolute value of the opening deviation is within a predetermined range,
After the deviation output unit outputs the control deviation, the acquisition of each opening, the calculation of the opening deviation, the determination of the sign, and the determination of the absolute value, based on the determination result of the code And a state determination unit that determines whether or not the current state of the valve satisfies a predetermined condition for driving or stopping the valve.
The deviation determination unit determines whether the absolute value of the opening deviation is less than or equal to a first threshold value, and the absolute value of the opening deviation is greater than the first threshold value in absolute value. Judge whether it is less than or equal to the second threshold,
The state determination unit, based on the determination result by the first threshold value and the second threshold value for the opening deviation, and the determination result for the sign of the opening deviation, the current valve state, , Determine whether or not a predetermined condition for driving or stopping the valve is satisfied ,
Even if the absolute value of the opening deviation is within a predetermined range, the state determination unit changes the acquired target opening, and the code shown in the determination result of the code is the initial code determination. If the result or the sign opposite to the judgment result of the previous sign, it is judged that the current valve state satisfies the predetermined condition for driving the valve,
The deviation output unit outputs the control deviation to drive the valve when the state determination unit determines that the current state of the valve satisfies a predetermined condition for driving the valve. Valve control device. The state determination unit determines whether or not the code indicated by 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 whether it is 0. , It is determined that the code indicated by the determination result of the code is the opposite of 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. If there is no change in the acquired target opening, it is determined that the current valve state satisfies the predetermined condition for stopping the valve,
The deviation output unit outputs the control deviation as 0 and stops the valve when the state determination unit determines that the current state of the valve satisfies a predetermined condition for stopping the valve. The valve control device according to claim 1, wherein: