JP2006240339A - Fluid pressure control device and fluid pressure control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppose a new control technique for controlling a fluid pressure control valve in a system using a plurality of fluid pressure control valves arranged parallely. <P>SOLUTION: A target hydraulic pressure setting part 300 fetches a target hydraulic pressure value, and a current hydraulic pressure fetching part 302 fetches the pressure currently and actually supplied to a right front wheel cylinder as a fluid pressure actuating device. A deviation calculation part 304 calculates a difference of values of hydraulic pressure supplied from the current hydraulic pressure fetching part 302 and the target hydraulic pressure setting part 300. A feedback control volume calculating part 306 calculates a feedback control volume for reducing the difference. A distribution calculating part 308 distributes the feedback control volume to each of always-closed type linear valve 70 constituting a valve unit 40. A necessary current calculating part 310 calculates a current volume flown to a coil of the always-closed type linear valve 70 for flowing the distributed control volume, and a current output part 312 outputs the calculated current value to the predetermined always-closed type linear valve 70 of the valve unit 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluid pressure control device and a fluid pressure control method, and more particularly to improvement of control of a fluid pressure control valve when a fluid pressure operation device is operated using a plurality of fluid pressure control valves.

  2. Description of the Related Art Conventionally, fluid pressure such as hydraulic pressure or pneumatic pressure has been used as a drive source for actuators used in mechanical devices. For example, in an automobile, hydraulic pressure is used as a drive source for a wheel cylinder of a brake device. Usually, a fluid pressure source having a pressure higher than that required for a fluid pressure operating device such as a wheel cylinder is prepared. A fluid that controls the flow of the working fluid between the fluid pressure source and the fluid pressure operating device so that an optimum fluid pressure is provided to cause the fluid pressure operating device to perform a desired operation at a desired timing. A pressure control valve is arranged. As this fluid pressure control valve, for example, there is a poppet type valve that opens and closes a valve by utilizing a suction force by an electromagnetic action and a biasing force of a spring.

This poppet-type fluid pressure control valve is often used in devices that place importance on fail-safe, such as brake devices, because it is difficult for foreign matter to be caught due to its structure. For example, Patent Literature 1 discloses a fluid pressure control device using a poppet type fluid pressure control valve for fluid pressure control of a brake device.
JP 2001-260868 A

  By the way, in the case of a poppet type fluid pressure control valve, a fluid pressure source that exceeds the fluid pressure with respect to the fluid pressure required by the fluid pressure operating device is connected to the import side due to its structure. It is necessary to close the valve with an urging force exceeding the pressure. Therefore, the poppet type fluid pressure control valve is provided with a spring that can generate an urging force corresponding to the fluid pressure of the fluid pressure source, and an electromagnetic drive that generates a suction force to overcome the urging force and open the valve. Part is required. That is, when the required fluid pressure is large, the configuration of the fluid pressure control valve inevitably increases, and the power consumption for driving the electromagnetic drive unit of the fluid pressure control valve increases.

  For this reason, for example, there has been proposed one that secures a required fluid pressure by connecting a plurality of fluid pressure control valves having a capacity smaller than the fluid pressure required by the fluid pressure operating device. That is, there has been proposed a valve system that secures the required flow rate of the working fluid as a whole by arranging a plurality of small fluid pressure control valves that can be driven with low power in parallel.

  However, in such a system configured by arranging a plurality of fluid pressure control valves in parallel, there are still many points to be examined such as mutual interference, deterioration countermeasures, energy saving measures, etc. of each fluid pressure control valve. That is the current situation.

  The present invention has been made in view of such circumstances, and its object is to propose a new control technology for controlling a fluid pressure control valve in a system that uses a plurality of fluid pressure control valves arranged in parallel. There is to do.

  In order to solve the above-described problems, in one aspect of the present invention, a plurality of fluid pressure sources arranged in parallel between a fluid pressure source and a fluid pressure operation device operated by a fluid pressure supplied from the fluid pressure source, the fluid pressure A fluid pressure control valve for controlling a fluid pressure with respect to the operating device, and a feedback calculating means for calculating a feedback control amount for obtaining the target operating state from a deviation between the target operating state and the actual operating state of the fluid pressure operating device; , Distributing the calculated feedback control amount to each fluid pressure control valve, calculating a control amount for each fluid pressure control valve, and driving each fluid pressure control valve based on the distributed control amount And valve drive means.

  Here, the number of fluid pressure control valves arranged in parallel is arbitrary as long as it is two or more. Needless to say, the feedback control amount distributed to each fluid pressure control valve is equal to the total control amount that feeds back the total control amount distributed to each fluid pressure control valve, but is equally distributed to each fluid pressure control valve. Alternatively, it may be distributed unevenly.

  According to this aspect, the feedback control amount for obtaining the target operating state from the deviation between the target operating state of the fluid pressure operating device and the actual operating state is distributed to a plurality of fluid pressure control valves arranged in parallel. Since the individual fluid pressure control valves are controlled, it is possible to avoid that the individual fluid pressure control valves operate in response to the entire feedback control amount and interfere with each other. As a result, feedback control of a desired control amount can be performed smoothly as a whole of the plurality of fluid pressure control valves.

  In the above aspect, the distribution calculation means may distribute the control amount so that all the fluid pressure control valves arranged in parallel operate. According to this aspect, the usage frequency of each fluid pressure control valve can be made uniform, and deterioration management of the fluid pressure control valve can be easily performed. Also, by distributing the feedback control amount to each fluid pressure control valve, it becomes possible to reduce the feedback control amount assigned to each fluid pressure control valve, and the fluid pressure control valve has a low flow rate with stable opening / closing operation accuracy. The area can be used, and high-precision operation control can be performed.

  Further, in the above aspect, the apparatus further includes a feedforward calculation unit that calculates a feedforward control amount that causes the fluid pressure operating device to operate in a target operation state, and the distribution calculation unit includes the feedforward control amount and the feedback control amount. May be distributed to each of the plurality of fluid pressure control valves. According to this aspect, the necessary feedback control amount is reduced by performing the feedforward control. As a result, the overall control amount of feedback control using a plurality of fluid pressure control valves is reduced, and highly accurate control can be easily performed. In addition, by using a plurality of fluid pressure control valves arranged in parallel with feedforward control, the maximum fluid pressure required by the fluid pressure operating device can be handled by increasing or decreasing the number of fluid pressure control valves. Can do. That is, it is possible to cope with fluid pressure operating devices having various capacities only by preparing a standard fluid pressure control valve.

  In the above aspect, the distribution calculating means distributes the feedforward control amount to a predetermined fluid pressure control valve, and controls the fluid pressure control other than the fluid pressure control valve that distributes the feedback control amount to the feedforward control amount. You may make it distribute to a valve. According to the above aspect, by separating the fluid pressure control valve used in the feedforward control and the feedback control, it becomes possible to quickly perform the mutual control and smoothly perform the high-precision fluid pressure control. be able to. Since the feedback control amount is reduced by performing the feedforward control, the number of fluid pressure control valves dedicated to the feedback control can be reduced.

  In the above aspect, the distribution calculation unit may deactivate a predetermined fluid pressure control valve according to a total control amount including at least the feedback control amount. According to this aspect, the number of fluid pressure control valves that are actually operated can be reduced, so that power consumption for the fluid pressure control valve can be suppressed.

  In the above aspect, the distribution calculation means may select the non-operating fluid pressure control valve for each distribution operation. According to this aspect, the non-operating fluid pressure control valves can be sequentially changed, so that deterioration due to wear of each fluid pressure control valve can be made uniform. As a result, it is possible to contribute to improving the durability of the entire fluid pressure control device.

  In order to solve the above-mentioned problem, in another aspect of the present invention, a plurality of fluid pressure control valves are provided between a fluid pressure source and a fluid pressure operating device that operates by fluid pressure supplied from the fluid pressure source. A fluid pressure control method that is arranged in parallel and controls the fluid pressure with respect to the fluid pressure operating device by the fluid pressure control valve, wherein the target is determined from a deviation between a target operating state of the fluid pressure operating device and an actual operating state. A feedback control amount for obtaining an operating state is calculated, the control amount is distributed to the fluid pressure control valves arranged in parallel, and a control amount for each fluid pressure control valve is determined.

  According to this aspect, the feedback control amount for obtaining the target operating state from the deviation between the target operating state of the fluid pressure operating device and the actual operating state is distributed to a plurality of fluid pressure control valves arranged in parallel. Since each fluid pressure control valve is controlled, it is possible to avoid that each fluid pressure control valve operates in response to the entire feedback control amount and interferes with each other. Control amount feedback control can be performed smoothly.

  According to the fluid pressure control device and the fluid pressure control method of the present invention, feedback control using a plurality of fluid pressure control valves can be performed with high accuracy. Further, feedback control of the fluid pressure control valve can be performed smoothly.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings.

  The fluid pressure control device according to the present embodiment controls a plurality of fluid pressure control valves arranged in parallel between a fluid pressure source and a fluid pressure operation device that operates by a fluid pressure supplied from the fluid pressure source. Is. In particular, based on the deviation between the target operating state of the fluid pressure operating device and the actual operating state, the feedback control amount for obtaining the target operating state is distributed to each of the fluid pressure control valves arranged in parallel. The pressure control valves can operate smoothly without interfering with each other. In the present embodiment, a disc brake device mounted on a vehicle and driven by hydraulic pressure is shown as an example of a fluid pressure operating device.

  FIG. 1 is an explanatory diagram showing the overall configuration of a vehicle braking device 100 and an electronic control unit 200 (hereinafter referred to as “ECU 200”) to which the fluid pressure control device of the present embodiment is applied. The vehicle braking device 100 mainly includes an actuator 80 and a master cylinder 14 other than the actuator 80. The vehicle braking device 100 is an electronically controlled brake system (ECB), and can detect the operation amount of the brake pedal with a sensor, calculate the optimum brake hydraulic pressure, and operate the brakes independently of the four wheels.

  The brake pedal 12 is provided with a stroke sensor 46 that detects the depression stroke. The master cylinder 14 pumps the brake oil, which is a working fluid, in response to the depression operation of the brake pedal 12 by the driver.

  One end of a brake hydraulic pressure control conduit 16 for the right front wheel and a brake hydraulic pressure control conduit 17 for the left front wheel are connected to the master cylinder 14, and these brake hydraulic pressure control conduits exhibit the braking force of the right front wheel and the left front wheel, respectively. It is connected to wheel cylinders 20FR and 20FL for the right front wheel and the left front wheel. In the present embodiment, as the brake device, a disc brake device that exerts a braking force by driving the brake pads to be opened and closed by the wheel cylinders 20FR and 20FL and the wheel cylinders 20RR and 20RL, which will be described later, and sandwiching the disc rotor is illustrated. A right front wheel electromagnetic on / off valve 22FR and a left front wheel electromagnetic on / off valve 22FL are interposed in the middle of the brake hydraulic control conduits 16 and 17 for the right front wheel and the left front wheel. The right front wheel electromagnetic on-off valve 22FR and the left front wheel electromagnetic on-off valve 22FL are open when not energized, and are switched to a closed state when a brake operation is detected (this is referred to as a “normally open type”).

  A right master pressure sensor 48FR and a left master pressure sensor 48FL for measuring the master cylinder fluid pressure on the right front wheel side and the left front wheel side are provided in the middle of the brake hydraulic pressure control conduits 16 and 17, respectively. When the driver depresses the brake pedal 12, the stroke sensor 46 detects the amount of depression, but the brake pedal 12 is also measured by measuring the master cylinder hydraulic pressure by the right master pressure sensor 48FR and the left master pressure sensor 48FL. The stepping operation force is detected. The master cylinder hydraulic pressure is monitored by two pressure sensors from the viewpoint of fail-safe.

  A reservoir tank 26 is connected to the master cylinder 14, and a stroke simulator 24 that creates a reaction force according to the operation amount of the driver is connected via the on-off valve 23. The on-off valve 23 is a normally closed solenoid valve that is closed when not energized and switches to an open state when a brake is operated. Further, one end of a hydraulic supply / discharge conduit 28 is connected to the reservoir tank 26. The hydraulic supply / discharge conduit 28 is provided with an oil pump 34 driven by a motor 32. The discharge side of the oil pump 34 is a high-pressure conduit 30, and an accumulator 50 and a relief valve 53 are provided. The accumulator 50 accumulates brake oil that has been brought to a high pressure in the range of 14 to 22 MPa (hereinafter referred to as “control range”) by the oil pump 34. The relief valve 53 opens when the accumulator pressure is abnormally high, for example, a high pressure such as 25 MPa, and releases high-pressure brake oil to the hydraulic supply / discharge conduit 28.

  The high pressure conduit 30 is provided with an accumulator pressure sensor 51 that measures the accumulator pressure. An accumulator pressure that is an output of the accumulator pressure sensor 51 is input to the ECU 200 described later, and the motor 32 is controlled so that the accumulator pressure falls within the control range.

  The high-pressure conduit 30 includes an electromagnetic flow control valve for pressure increase (hereinafter referred to as a wheel cylinder 20) included in the disc brake device for increasing the hydraulic pressure of the wheel cylinders 20FR, 20FL, 20RL, and 20RR (hereinafter sometimes referred to as the wheel cylinder 20). , And linear units for pressure reduction for reducing the hydraulic pressure state, and valve units 40 and 42 are connected.

  As shown in FIG. 2A, the valve unit 40 is in a closed state when not energized, and a normally closed linear valve 70 that is energized and opened when necessary is used for pressure increase and pressure reduction. Are arranged in parallel. The valve unit 40 illustrated in FIG. 2A includes, for example, four normally closed linear valves 70a, 70b, 70c, and 70d arranged in parallel (normally closed when no specific valve is indicated). And the import side of each normally closed linear valve 70 is connected to the high pressure conduit 30. Further, the out-port side of the normally closed linear valves 70a, 70b, 70c, and 70d is connected to the brake hydraulic control conduit 16 for the right front wheel or the brake hydraulic control conduit 17 for the left front wheel and arranged in parallel. For example, it is connected to the import side of four normally closed linear valves 70e, 70f, 70g, and 70h (in the case of not pointing to a specific valve, it may be expressed as a normally closed linear valve 70). . Furthermore, the outport side of the linear valves 70e, 70f, 70g, 70h is connected to the hydraulic supply / discharge conduit 28.

  That is, when the wheel cylinder 20FR connected to the brake hydraulic pressure control conduit 16 for the right front wheel or the wheel cylinder 20FL connected to the brake hydraulic pressure control conduit 17 for the left front wheel is increased, the linear valves 70a, 70b, 70c, At least one of 70d is energized according to the amount of pressure increase to open the valve, and the normally closed linear valves 70e, 70f, 70g, and 70h are all deenergized and closed to supply hydraulic pressure from the high pressure conduit 30. Increase the pressure. Conversely, when the wheel cylinder 20FR or the wheel cylinder 20FL is depressurized, all of the normally closed linear valves 70a, 70b, 70c, 70d are closed, and at least the normally closed linear valves 70e, 70f, 70g, 70h are closed. One valve is opened according to the pressure reduction amount, and the hydraulic pressure is supplied to the hydraulic supply / discharge conduit 28 to reduce the pressure.

  On the other hand, as shown in FIG. 2B, the valve unit 42 has a plurality of normally-closed linear valves 70 arranged in parallel for pressure increase, and is open when not energized for pressure reduction. A plurality of normally open linear valves 72 that are sometimes energized and closed are arranged in parallel. The valve unit 42 illustrated in FIG. 2B has, for example, four normally closed linear valves 70a, 70b, 70c, and 70d arranged in parallel, and the import side of each normally closed linear valve 70 is provided on the import side. Connected to the high pressure conduit 30. Further, the out-port side of the normally closed linear valves 70a, 70b, 70c, 70d is connected to the brake hydraulic control conduit 18 for the right rear wheel or the brake hydraulic control conduit 19 for the left rear wheel, and arranged in parallel. For example, it is connected to the import side of four normally open linear valves 72a, 72b, 72c, 72d (in the case of not pointing to a specific valve, it may be expressed as a normally open linear valve 72). . Furthermore, the out-port side of the linear valves 72a, 72b, 72c, 72d is connected to the hydraulic supply / discharge conduit 28.

  That is, when the pressure of the wheel cylinder 20RL connected to the brake hydraulic pressure control conduit 18 for the left rear wheel or the wheel cylinder 20RR connected to the brake hydraulic pressure control conduit 19 for the right rear wheel is increased, the normally closed linear valve 70a. , 70b, 70c, and 70d are energized in accordance with the amount of pressure increase to open the valve, and the normally open linear valves 72a, 72b, 72c, and 72d are all energized to close the valve. To increase the pressure. Conversely, when the wheel cylinder 20RL or the wheel cylinder 20RR is depressurized, all the normally closed linear valves 70a, 70b, 70c, 70d are closed, and at least the normally open linear valves 72a, 72b, 72c, 72d are closed. One is opened, and hydraulic pressure is supplied to the hydraulic supply / discharge conduit 28 to reduce the pressure.

  Note that the normally closed linear valve 70 is used for pressure reduction of the valve unit 40 that controls the front wheel side, and the normally open linear valve 72 is used for pressure reduction of the valve unit 42 that controls the rear wheel side. This is to perform fail-safe when a working fluid leaks to the linear valve 70 for pressure. As shown in FIG. 1, when the predetermined hydraulic pressure from the accumulator 50 cannot be supplied to the front wheel side, the hydraulic pressure generated in the master cylinder 14 by operating the brake pedal 12 is directly applied to the wheel cylinders 20FR, FL on the front wheel side. A brake hydraulic pressure control conduit 16 for the right front wheel and a brake hydraulic pressure control conduit 17 for the left front wheel are connected to each other to form a backup circuit for the brake hydraulic pressure. In this configuration, consider a case where the working fluid of the normally closed linear valve 70 for pressure increase leaks on the front wheel side. In that case, since the out-port side of the normally closed linear valve 70 is connected to the master cylinder 14 via the electromagnetic on-off valves 22FR and 22FL, the working fluid flows to the master cylinder 14 side even when leakage occurs. No hydraulic pressure is applied to the wheel cylinders 20FR and 20FL on the front wheel side. That is, there is no brake drag.

  On the other hand, as shown in FIG. 1, since the back-up circuit connected to the normal master cylinder 14 side is not provided on the rear wheel side, the working fluid of the normally closed linear valve 70 for pressure increase on the rear wheel side is not provided. In the case of leakage, if the linear valve for pressure reduction is a normally closed type, the leaked working fluid flows into the wheel cylinders 20RL and RR, generating a braking force and causing dragging. Therefore, by using the normally open linear valve 72 on the pressure reducing side, the leaked working fluid can be returned to the reservoir tank 26 via the hydraulic supply / discharge conduit 28 even during non-control. That is, it functions as a fail safe when each linear valve is not energized. Of course, the type of the linear valve to be arranged in parallel can be appropriately selected depending on the configuration of the vehicle braking device 100.

  Returning to FIG. 1, in the vicinity of the wheel cylinders 20FR, 20FL, 20RR, 20RL of the right front wheel, the left front wheel, the right rear wheel, and the left rear wheel, the right front wheel, the left front wheel, Pressure sensors 44FR, 44FL, 44RR, and 44RL for the right rear wheel and the left rear wheel (may be referred to as the pressure sensor 44 when not pointing to a specific pressure sensor) are provided.

  The ECU 200 mainly controls the electromagnetic on-off valves 22FR and 22FL, the on-off valve 23, the motor 32, the two valve units 40, the two valve units 42, and the like. The ECU 200 includes an arithmetic unit 202 using a microcomputer, a ROM 204 that stores various control programs, and a RAM 206 that is used as a work area for data storage and program execution.

  A signal indicating the depression stroke of the brake pedal 12 (hereinafter referred to as a stroke signal) is supplied to the arithmetic unit 202 via the stroke sensor 46. The right master pressure sensor 48FR and the left master pressure sensor 48FL are supplied with a signal indicating a master cylinder hydraulic pressure (hereinafter referred to as a master cylinder hydraulic pressure signal), and the accumulator pressure sensor 51 is a signal indicating an accumulator pressure (hereinafter referred to as an accumulator pressure signal). Is supplied).

  The ROM of ECU 200 stores a predetermined braking control flow. The arithmetic unit 202 calculates the target deceleration of the vehicle based on the stroke signal and the master cylinder hydraulic pressure signal, calculates the target wheel cylinder hydraulic pressure of each wheel based on the calculated target deceleration, and calculates the wheel cylinder fluid of each wheel. The valve units 40 and 42 are controlled so that the pressure becomes the target wheel cylinder hydraulic pressure.

  The oil pump 34 driven by the motor 32 draws up brake oil from the reservoir tank 26 through the hydraulic supply / discharge conduit 28 and accumulates the brake oil at high pressure in the accumulator 50. The high hydraulic pressure of the accumulator 50 is supplied to each wheel cylinder 20 by controlling the opening and closing of the valve units 40 and 42 according to the target wheel cylinder hydraulic pressure.

  When high-pressure brake oil is consumed from the accumulator 50 by depressing the brake pedal 12, the ECU 200 operates the motor 32 to drive the oil pump so that the pressure of the accumulator 50 is always within the control range, Accumulator 50 accumulates the brake oil at a high pressure. This pressure accumulation operation is automatically executed according to the detection value of the accumulator pressure sensor 51.

  FIG. 3 is a functional block diagram illustrating the internal structure of the arithmetic unit 202 of the ECU 200, and particularly shows functional blocks related to the calculation of the feedback control amount related to the present embodiment.

  The calculation unit 202 includes a target hydraulic pressure setting unit 300, a current hydraulic pressure acquisition unit 302, a deviation calculation unit 304, a feedback control amount calculation unit 306, a distribution calculation unit 308, a required current calculation unit 310, a current output unit 312 and the like. In the case of the present embodiment, individual hydraulic control is performed for each of the right front wheel wheel cylinder 20FR, the left front wheel wheel cylinder 20FL, the right rear wheel wheel cylinder 20RR, and the left rear wheel wheel cylinder 20RL. All of the control procedures are substantially the same, and each of them is processed in parallel in the arithmetic unit 202. Therefore, in the present embodiment, the procedure of hydraulic control will be described using the right front wheel cylinder 20FR as an example.

  The target hydraulic pressure setting unit 300 indicates the next target operation state of the wheel cylinder 20 at the next control timing for obtaining the braking force requested by the driver based on the depression stroke of the brake pedal 12 detected by the stroke sensor 46. Get hydraulic value. In the case of controlling the right front wheel cylinder 20FR or the left front wheel cylinder 20FL, the target hydraulic pressure setting unit 300 generates the master cylinder 14 based on the signals from the right and left master pressure sensors 48FR and 48FL. The target hydraulic pressure value at the next control timing for obtaining the braking force requested by the driver can be obtained. Further, when the vehicle-side system requests a control force based on various information acquired by the vehicle braking device 100, the braking force may be set as a target hydraulic pressure value. The current hydraulic pressure acquisition unit 302 acquires the pressure that is currently acting, which is a value indicating the actual operation state of the wheel cylinder 20FR for the right front wheel, via the pressure sensor 44FR for the right front wheel.

  The deviation calculation unit 304 calculates the both hydraulic pressure values based on the hydraulic pressure actually applied to the current wheel cylinder 20FR provided from the current hydraulic pressure acquisition unit 302 and the target hydraulic pressure value provided from the target hydraulic pressure setting unit 300. Calculate the difference. Then, the feedback control amount calculation unit 306 calculates a deviation between the hydraulic pressure actually applied to the current wheel cylinder 20FR provided from the current hydraulic pressure acquisition unit 302 and the target hydraulic pressure value provided from the target hydraulic pressure setting unit 300. The amount of feedback control for reducing and setting the wheel cylinder 20FR to the target operation state is calculated. In the present embodiment, the feedback control amount is the flow rate of the working fluid in the valve unit 40.

  The distribution calculation unit 308 distributes the feedback control amount provided from the feedback control amount calculation unit 306 to each normally closed linear valve 70 constituting the valve unit 40. There are various distribution methods, which will be described later in detail. For example, the feedback control amount may be distributed equally to each normally closed linear valve 70 or may be distributed based on a predetermined distribution ratio. Moreover, you may distribute only with the specific normally closed linear valve 70. FIG.

  The required current calculation unit 310 executes the valve opening of the normally closed linear valve 70 that is required to secure the control amount distributed to each normally closed linear valve 70, that is, the flow rate of the distributed working fluid. Therefore, the amount of current flowing through the coil of the normally closed linear valve 70 is calculated. In other words, a current for canceling the set load of the spring closing the normally closed linear valve 70 is calculated, and further, a current value for compressing the spring is calculated according to the distributed feedback control amount. The current output unit 312 outputs the calculated current value to the predetermined normally closed linear valve 70 of the valve unit 40. Therefore, in this embodiment, the required current calculation unit 310 and the current output unit 312 constitute a valve driving unit.

  FIG. 4 shows a flowchart showing a procedure of processing performed by the arithmetic unit 202. The arithmetic unit 202 sets the target hydraulic pressure value of the wheel cylinder 20FR at the next timing via the target hydraulic pressure setting unit 300 (S100). Subsequently, the current hydraulic pressure acquisition unit 302 acquires the hydraulic pressure value acting on the current wheel cylinder 20FR from the pressure sensor 44FR (S101). Subsequently, the deviation calculating unit 304 and the feedback control amount calculating unit 306 target the wheel cylinder 20FR based on the difference between the target hydraulic pressure value at the next control timing acquired at S100 and the current hydraulic pressure value acquired at S101. A feedback control amount for setting the operation state is calculated (S102). This feedback control calculation is performed using, for example, a well-known PID control.

  Next, the distribution calculation unit 308 distributes the feedback control amount calculated in S102 to each normally closed linear valve 70 constituting the valve unit 40 (S103). When the total feedback control amount calculated by the feedback control amount calculation unit 306 is the pressure increase adjustment, the distribution calculation unit 308 distributes evenly to the normally closed linear valves 70a to 70d shown in FIG. That is, the entire four normally closed linear valves 70a to 70d are set to the total control amount of the feedback control. At this time, it goes without saying that the control amount distributed to each normally closed linear valve 70 is distributed so as to be equal to or less than the maximum flow rate of the normally closed linear valve 70. The required current calculator 310 calculates a valve opening current for outputting the control amount distributed to each normally closed linear valve 70 by each normally closed linear valve 70 (S104). That is, the current value for canceling the set load of the spring closing the normally closed linear valve 70 is calculated, and the spring is compressed in accordance with the control amount distributed to each normally closed linear valve 70. Perform the operation. In addition, when the feedback control amount is evenly distributed, the current calculation may be performed collectively. However, when there is a difference in characteristics for each normally closed linear valve 70, the current status is individually determined based on the characteristic information. Is calculated.

  Then, the current output unit 312 outputs a command current for opening the valve for each normally closed linear valve 70 based on the calculated current value (S105), and opens each normally closed linear valve 70. Drive, complete one control cycle, return to S100 again, and shift to control at the next control timing.

  In this manner, the feedback control amount is distributed to the plurality of normally closed linear valves 70 arranged in parallel, and each normally closed linear valve 70 is controlled. As a result, each normally closed linear valve 70 operates so as to achieve the total control amount of feedback to the valve unit 40, thereby preventing the normally closed linear valves 70 constituting the valve unit 40 from interfering with each other. be able to. Then, the feedback control of the desired control amount can be performed smoothly for the plurality of normally closed linear valves 70 as a whole. Further, the frequency of use of each normally closed linear valve 70 can be made uniform, and deterioration management of the normally closed linear valve 70 can be easily performed. Further, by distributing the feedback control amount to each normally closed linear valve 70, the feedback control amount of each normally closed linear valve 70 can be reduced. As a result, the normally closed linear valve 70 can use a low flow rate range in which opening / closing operation accuracy is stable, and high-precision operation control can be performed.

  In the above description, an example in which the control amount is uniformly distributed to the normally closed linear valves 70a to 70d for pressure increase or the normally closed linear valves 70e to 70h for pressure reduction arranged in parallel has been shown. If the total control amount distributed to each normally closed linear valve 70 matches the total control amount calculated by the feedback control amount calculation unit 306, the distribution ratio to each normally closed linear valve 70 is arbitrary and uneven. Even when the distribution is performed, the same effect as when the uniform distribution is performed can be obtained. In the case of non-uniform distribution, distribution may be performed for all normally closed linear valves 70, or a normally closed linear valve 70 having a distribution amount of “zero” may be provided. In this case, it is possible to set a stop valve, and it is possible to improve the degree of freedom of valve deterioration management. Further, when the feedback control amount is very small, if the control amount is distributed among all the normally closed linear valves 70, the control amount per one of the normally closed linear valves 70 becomes too small, and the normally closed type is normally closed. The operation of the mold linear valve 70 may become unstable. In this case, by providing the stop valve, the control amount handled by one normally closed linear valve 70 can be collected into an amount suitable for the valve operation. In the case of a linear valve, the opening degree of the valve and the flow rate are in a proportional relationship. However, when the opening degree is extremely small or conversely extremely large, the accuracy of the flow rate with respect to the opening degree decreases. Therefore, by providing the stop valve, it becomes possible to positively use the high-precision operation region of the normally-closed linear valve 70, and the vehicle braking device 100 can be feedback-controlled with high accuracy.

  If the total feedback control amount calculated in S102 is to adjust the pressure reduction, in S103, the distribution calculation unit 308 distributes the control amount with the normally closed linear valves 70e to 70h as distribution targets, and the wheel cylinder 20FR. From which the working fluid is released to the hydraulic supply / discharge conduit 28. In this case as well, the interference between the normally closed linear valves 70 can be prevented in the same manner as described above, the deterioration can be managed, and the control can be performed in a stable low flow switching operation region, and the same effect as described above can be obtained. .

  By the way, when performing valve control etc., feedforward control may be performed in addition to the feedback control as described above. FIG. 5 is a functional block diagram for explaining the internal structure when the arithmetic unit 202 performs feedforward control in addition to feedback control. Like FIG. 3, the arithmetic operation of the feedback control amount and the feedforward related to the present embodiment are performed. Only functional blocks related to control amount calculation are shown. Moreover, the same code | symbol is attached | subjected to the element which has a function equivalent to FIG. 3, and detailed description is abbreviate | omitted.

  5 includes a target hydraulic pressure setting unit 300, a current hydraulic pressure acquisition unit 302, a deviation calculation unit 304, a feedback control amount calculation unit 306, a distribution calculation unit 308, a required current calculation unit 310, and a current output unit 312. A required oil amount calculation unit 314 and a feedforward control amount calculation unit 316 are provided. Also in FIG. 5, the procedure of hydraulic control will be described by taking the wheel cylinder 20FR of the right front wheel as an example.

  The target hydraulic pressure setting unit 300 sets a target hydraulic pressure value at the next control timing for obtaining the braking force requested by the driver based on the depression stroke of the brake pedal 12 detected by the stroke sensor 46. The current hydraulic pressure acquisition unit 302 acquires the pressure that is currently actually supplied to the wheel cylinder 20FR for the right front wheel via the pressure sensor 44FR for the right front wheel.

  The required oil amount calculation unit 314 applies the target oil pressure to the wheel cylinder 20FR at the next control timing based on the currently set target oil pressure value and the target oil pressure value requested by the driver provided from the target oil pressure setting unit 300. Calculate the amount of oil required to generate the value. Then, the feedforward control amount calculation unit 316 calculates a feedforward control amount for obtaining the target hydraulic pressure value at the next control timing based on the required oil amount calculated by the required oil amount calculation unit 314. That is, the increase / decrease for realizing the control amount required at the next control timing is calculated.

  On the other hand, the deviation calculation unit 304 is based on the oil pressure actually applied to the current wheel cylinder 20FR provided from the current oil pressure acquisition unit 302 and the target oil pressure value provided from the target oil pressure setting unit 300. The difference between values is calculated. Then, the feedback control amount calculation unit 306 calculates a deviation between the hydraulic pressure actually applied to the current wheel cylinder 20FR provided from the current hydraulic pressure acquisition unit 302 and the target hydraulic pressure value provided from the target hydraulic pressure setting unit 300. A feedback control amount for reduction is calculated.

  The distribution calculation unit 308 uses the feedforward control amount calculation unit 316 and the feedback control amount calculation unit 306 to feed the feedforward control amount and the feedback control amount to each normally closed type for pressure increase or pressure reduction constituting the valve unit 40. Distribute to the linear valve 70. For example, the total of the feedforward control amount and the feedback control amount is evenly distributed to each normally closed linear valve 70, the feedforward control amount is predetermined to the normally closed linear valve 70, and the feedback control amount is set to another predetermined amount. To the normally closed linear valve 70.

  The required current calculation unit 310 executes the valve opening of the normally closed linear valve 70 that is required to secure the control amount distributed to each normally closed linear valve 70, that is, the flow rate of the distributed working fluid. Therefore, the amount of current flowing through the coil of the normally closed linear valve 70 is calculated. The current output unit 312 outputs the calculated current value to the predetermined normally closed linear valve 70 of the valve unit 40.

  FIG. 6 is a flowchart showing a procedure of processing performed by the arithmetic unit 202 shown in FIG. The arithmetic unit 202 sets the target hydraulic pressure value of the wheel cylinder 20FR at the next timing via the target hydraulic pressure setting unit 300 (S200). Subsequently, the current hydraulic pressure acquisition unit 302 acquires the current hydraulic pressure value of the wheel cylinder 20FR from the pressure sensor 44FR (S201). The required oil amount calculation unit 314 and the feedforward control amount calculation unit 316 calculate the feedforward control amount based on the target hydraulic pressure value set in S200 and the current target hydraulic pressure value (S202). Subsequently, the deviation calculation unit 304 and the feedback control amount calculation unit 306 calculate the feedback control amount based on the difference between the target hydraulic pressure value at the next control timing set in S200 and the current hydraulic pressure value acquired in S201. (S203). This feedback control calculation is performed using, for example, a well-known PID control.

  Next, the distribution calculation unit 308 distributes the feedforward control amount and the feedback control amount calculated in S202 and S203 to each normally closed linear valve 70 constituting the valve unit 40 (S204).

  The distribution calculation unit 308 can select a distribution method based on the total amount of control amounts calculated by the feedforward control amount calculation unit 316 and the feedback control amount calculation unit 306. For example, when both the feedforward control amount and the feedback control amount are pressure increase adjustments, or when both are pressure reduction adjustments, a plurality of normally closed types are maintained with the feedforward control amount and the feedback control amount separated from each other. It can be distributed to the linear valve 70.

  For example, when the total number of normally closed linear valves 70 arranged in parallel is n, the feedforward control amount is set to the first normally closed linear valve 70 to the sth (1 ≦ s ≦ n) normally closed linear valve. The (s + 1) th normally closed linear valve 70 to the nth normally closed linear valve 70 are distributed to distribute the feedback control amount. At this time, the total feedforward control amount distributed to the first to s-th normally closed linear valve 70 is made to match the total control amount calculated by the feedforward control amount calculation unit 316. Similarly, the total feedback control amount distributed to the (s + 1) to n-th normally closed linear valve 70 and the total control amount calculated by the feedback control amount calculation unit 306 are made to coincide.

  Then, the necessary current calculation unit 310 calculates a valve opening current for outputting the control amount distributed to each normally closed linear valve 70 by each normally closed linear valve 70 (S205). Based on the calculated current value, the current output unit 312 outputs a command current for opening each normally closed linear valve 70 (S206), and opens each normally closed linear valve 70. After completing one control cycle, the process returns to S200 again and shifts to control at the next control timing.

  In this way, by performing feedforward control using a plurality of normally closed linear valves 70, it is possible to reduce the feedforward control amount flowing through each normally closed linear valve 70. As a result, the normally closed linear valve 70 can use a low flow rate range in which opening / closing operation accuracy is stable, and high-precision feedforward control can be performed. Further, as a result of highly accurate feedforward control, the required feedback control amount is reduced. As a result, the normally closed linear valve 70 can be used in a low flow rate range in which the opening / closing operation accuracy is stable even in feedback control, and the vehicle braking device 100 can be controlled with high accuracy. Further, by using a plurality of normally closed linear valves 70 arranged in parallel with the feedforward control, the number of normally closed linear valves 70 can be increased or decreased with respect to the maximum fluid pressure required by the wheel cylinder 20FR. Can respond. That is, it is possible to deal with the wheel cylinders 20FR having various capacities only by preparing a small and reasonable standard normally closed linear valve 70. Even when the error due to the feedforward control is large and the feedback control amount increases, the plurality of normally closed linear valves 70 are assigned for feedback control, so that smooth feedback control can be performed.

  Further, as described above, when the feedforward control is performed, the control amount of the feedback control is reduced. Therefore, when distributing the feedforward control amount and the feedback control amount to the plurality of normally closed linear valves 70 in a state where the feedforward control amount and the feedback control amount are separated from each other, a valve that sets the distribution of the feedback control amount to “zero” can be provided. That is, the distribution ratio can be set to “zero”. For example, even if there are three normally-closed linear valves 70 to be distributed, two of them are “zero” distribution, and the number of normally-closed linear valves 70 that are substantially used for feedback control can be made one. In this case, interference between the normally closed linear valves 70 during feedback control can be prevented, and the normally closed linear valve 70 can be reduced even when the feedback control amount decreases as a result of the feedforward control. It becomes possible to operate in the optimum operation region of the flow rate, and the vehicle braking device 100 can be stably controlled.

  In addition, the feedforward control amount calculated by the feedforward control amount calculation unit 316 is distributed equally or non-uniformly to all the normally closed linear valves 70 (1 to n-th) arranged in parallel, and the feedback control amount calculation unit Similarly, the feedback control amount calculated in 306 may be distributed equally or unevenly to all the normally closed linear valves 70. In this case, the total feedforward control amount distributed to each normally closed linear valve 70 matches the feedforward control amount calculated by the feedforward control amount calculation unit 316 and is distributed to each normally closed linear valve 70. The total feedback control amount is made to match the feedback control amount calculated by the feedback control amount calculation unit 306. Further, the total amount of control distributed to each normally closed linear valve 70 should not exceed the maximum flow rate of the normally closed linear valve 70.

  In this way, by distributing the feedforward control amount and the feedback control amount using all the normally closed linear valves 70, the control amount distributed to each normally closed linear valve 70 is reduced, and the In the closed linear valve 70, a low flow rate range in which the opening / closing operation accuracy is stable can be used, and highly accurate operation control can be performed.

  When the distribution amount is calculated by the distribution calculation unit 308, the feedforward control amount and the feedback control amount may be separately distributed as described above, but the feedforward control amount and the feedback control amount are added. The combined total control amount may be calculated and distributed to the normally closed linear valves 70 arranged in parallel. In this case, even when feedforward control and feedback control are performed, equal control of each normally closed linear valve 70 can be easily performed. Of course, the total control amount may be distributed unevenly.

  Further, when either one of the feedforward control amount and the feedback control amount is a pressure increase adjustment and the other is a pressure reduction adjustment, the normally closed type is driven by determining whether the total control amount is a pressure increase adjustment or a pressure reduction adjustment. Selection of the linear valve 70 can be performed quickly. For example, when the feedforward control amount is calculated as +3 cc and the feedback control amount is calculated as −1 cc, the total control amount is +2 cc, and the control amount is distributed to the normally closed linear valves 70a to 70d on the pressure increasing side. For example, when the feedforward control amount is calculated as +2 cc and the feedback control amount is calculated as -3 cc, the total control amount is -1 cc, and the control amount is distributed to the normally closed linear valves 70e to 70h on the decompression side. Is done.

  By the way, when the wheel cylinder 20FR is operated, the allowable capacity of the normally closed linear valve 70 arranged in parallel to the total control amount required for operating the wheel cylinder 20FR in a desired state may be exceeded. That is, the normally closed linear valve 70 arranged in parallel may have a margin. In the example described above, the feedback control amount or the total control amount of feedback and feedforward is distributed using all the normally closed linear valves 70 arranged in parallel. A certain number of normally closed linear valves 70 can be calculated, and at a certain control timing, a normally closed linear valve 70 that operates and a normally closed linear valve 70 that does not operate and stops can be provided. That is, distribution of the total control amount based on feedforward control or feedback control can be distributed only to the selected normally closed linear valve 70.

  For example, in FIG. 5, the total control amount obtained by combining the feedforward control amount calculated by the feedforward control amount calculation unit 316 and the feedback control amount calculated by the feedback control amount calculation unit 306 is as shown in FIG. Control is performed by operating the 1st to pth (1 ≦ p ≦ n) normally closed linear valves 70 out of the 1st to nth normally closed linear valves 70 (total number of linear valves n) arranged in parallel. If possible, the distribution calculation unit 308 distributes the control amount to the 1st to p-th normally closed linear valves 70. In this case, the process shown in FIG. 8 is executed in S204 of the flowchart shown in FIG. That is, the number of operations of the normally closed linear valve 70 is calculated from the total control amount based on the feedforward control amount calculated in S202 of FIG. 6 and the feedback control amount calculated in S203 (S300), and the normal use actually used. The closed linear valve 70 is selected (S301). This selection can be performed arbitrarily. For example, the 1st to pth normally closed linear valves 70 are selected. Then, the distribution calculation unit 308 distributes the control amount to the selected normally closed linear valve 70 (S302). Thereafter, the process returns to S205 in FIG. 6 to calculate the valve opening current, and the current output unit 312 outputs the command current to the normally closed linear valve 70 selected in S206.

  Normally, the oil consumption of the wheel cylinder 20FR is large in the low pressure range, so the number of wheel cylinders 20FR used at the initial stage of control becomes the maximum number p of normally closed linear valves 70 used this time in the vehicle braking device 100. . However, the maximum number including the margin may be p + 1.

  Thus, a normally closed linear valve for controlling the hydraulic pressure of the wheel cylinder 20FR is provided by providing a valve that stops the number of normally closed linear valves 70 used for feedback control and feedforward control to a minimum. 70 power consumption can be reduced. In addition, by providing a stop valve, it is possible to simplify the heat countermeasures of the driver that controls the electromagnetic drive unit of the normally closed linear valve 70, which enables the use of low-cost elements and simplification of the structure. Can be easily performed, which can contribute to the cost reduction of the fluid pressure control apparatus as a whole.

  Further, it is preferable that the non-operating normally closed linear valve 70 is selected by the distribution calculation unit 308 for each control amount distribution operation. For example, when distribution is performed to the 1st to pth normally closed linear valves 70 at a certain control timing, the (p + 1) th normally closed linear valve 70 is selected at the next control timing. By changing such a selection object, the normally closed linear valve 70 to be stopped can be set evenly. As a result, for each normally closed linear valve 70, the number of operations can be reduced, and deterioration can be reduced. Furthermore, since the normally closed linear valve 70 deteriorates evenly, the leakage of the working fluid due to the deterioration is prevented from concentrating on a specific normally closed linear valve 70, and the valve unit 40 as a whole delays the timing that becomes the use limit. be able to. That is, it can contribute to improvement of durability.

  In the present embodiment, a vehicle braking device is shown as an example of applying a fluid pressure control device that controls a plurality of fluid pressure control valves arranged in parallel. However, if the present invention is a control device that requires feedback control. The present invention can be applied to any device, and the same effect as that of the present embodiment can be obtained.

  In addition, in this embodiment, FIG. 2A shows an example in which a plurality of normally closed linear valves are arranged in parallel. However, if a valve opening / closing operation is appropriately selected, a normally open linear valve can be used. Alternatively, a normally closed linear valve and a normally open linear valve can be mixed and arranged in parallel, and the same effects as in the present embodiment can be obtained. In this case, it is possible to select a valve configuration suitable for the object to be controlled and other configurations, and it is possible to contribute to an improvement in design freedom and control freedom.

  Further, the flowcharts shown in FIGS. 4 and 6 show an example of the control procedure. At least the feedback control amount is distributed to the plurality of fluid pressure control valves arranged in parallel, and the entire plurality of fluid pressure control valves are arranged. Any control device may be used as long as the fluid pressure operating device is operated in a desired state. The control procedure can be changed as appropriate, and the same effects as in the present embodiment can be obtained.

  In addition, the configuration of the valve unit shown in FIG. 2 shows an example in which four normally closed linear valves or normally open linear valves are arranged in parallel, but the number of parallel arrangements is two or more. Any number may be used, and the parallel number can be appropriately selected according to the maximum operating pressure required by the fluid pressure operating device.

  In the above-described embodiment, the hydraulic system having oil as the working fluid has been described. However, the fluid pressure control apparatus of the present embodiment can be applied to a pneumatic system, and the same effects as those of the present embodiment can be obtained. Can do.

It is explanatory drawing explaining the structure of the vehicle braking device to which the fluid pressure control apparatus which concerns on this embodiment is applied. It is explanatory drawing which shows the parallel array example of the fluid pressure control valve contained in the fluid pressure control apparatus which concerns on this embodiment. It is a figure explaining the internal structure of the arithmetic unit contained in ECU of the fluid pressure control apparatus which concerns on this embodiment, and is a block diagram which shows the functional block relevant to feedback control. It is a flowchart explaining the operation | movement based on the functional block diagram shown in FIG. It is a figure explaining the internal structure of the arithmetic unit contained in ECU of the fluid pressure control apparatus which concerns on this embodiment, and is a block diagram which shows the functional block relevant to feedforward control and feedback control. It is a flowchart explaining the operation | movement based on the functional block diagram shown in FIG. It is explanatory drawing explaining determining the number of the fluid pressure control valves operated based on the total control amount in the fluid pressure control apparatus according to the present embodiment. 5 is a part of a flowchart illustrating a procedure for determining the number of fluid pressure control valves to be operated based on a total control amount in the fluid pressure control device according to the present embodiment.

Explanation of symbols

  20 wheel cylinder, 40, 42 valve unit, 70 normally closed linear valve, 72 normally open linear valve, 200 ECU, 202 arithmetic unit, 204 ROM, 206 RAM, 300 target hydraulic pressure setting unit, 302 current hydraulic pressure acquisition unit, 304 Deviation calculation unit, 306 feedback control amount calculation unit, 308 distribution calculation unit, 310 required current calculation unit, 312 current output unit, 314 required oil amount calculation unit, 316 feedforward control amount calculation unit.

Claims (7)

A plurality of fluid pressure control valves that are arranged in parallel between a fluid pressure source and a fluid pressure operation device that operates by a fluid pressure supplied from the fluid pressure source, and that controls a fluid pressure with respect to the fluid pressure operation device;
Feedback calculating means for calculating a feedback control amount for obtaining the target operating state from a deviation between the target operating state of the fluid pressure operating device and the actual operating state;
A distribution calculating means for distributing the calculated feedback control amount to each of the fluid pressure control valves, and calculating a control amount for each fluid pressure control valve;
Valve driving means for driving each fluid pressure control valve based on the distributed control amount;
A fluid pressure control device comprising:   2. The fluid pressure control device according to claim 1, wherein the distribution calculation unit distributes the control amount so that all the fluid pressure control valves arranged in parallel operate. Furthermore, it includes a feedforward calculating means for calculating a feedforward control amount for operating the fluid pressure operating device to a target operating state,
The fluid pressure control device according to claim 1, wherein the distribution calculation unit distributes the feedforward control amount and the feedback control amount to each of the plurality of fluid pressure control valves.   The distribution calculating means distributes the feedforward control amount to a predetermined fluid pressure control valve, and distributes the feedback control amount to a fluid pressure control valve other than the fluid pressure control valve that distributes the feedforward control amount. 4. The fluid pressure control device according to claim 3, wherein   5. The distribution calculation unit according to claim 1, wherein the distribution calculation unit deactivates a predetermined fluid pressure control valve according to at least a total control amount including the feedback control amount. Fluid pressure control device.   6. The fluid pressure control apparatus according to claim 5, wherein the distribution calculation means selects the fluid pressure control valve to be inactivated for each distribution operation. A plurality of fluid pressure control valves are arranged in parallel between a fluid pressure source and a fluid pressure operating device operated by a fluid pressure supplied from the fluid pressure source, and the fluid with respect to the fluid pressure operating device is provided by the fluid pressure control valve. A fluid pressure control method for controlling pressure,
A feedback control amount for obtaining the target operation state is calculated from a deviation between the target operation state and the actual operation state of the fluid pressure operating device, and the control amount is distributed to the fluid pressure control valves arranged in parallel. And determining a control amount for each fluid pressure control valve.

Images