JP2011068166A - Vehicular brake control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the driving behavior similar to that when any pump leakage is not present by adding the pump leakage. <P>SOLUTION: The pump leakage motor number of rotation corresponding to each specified differential pressure is obtained while generating the specified differential pressure by a differential pressure control valve, and the pump leakage motor number-of-rotation characteristic to the specified differential pressure is stored. When the motor is driven by the dynamic behavior control by using the pump leakage motor number-of-rotation characteristic to the specified differential pressure, the motor is driven at the target motor number of rotation with the pump leakage being added thereto. Thus, even when any pump leakage is present, the target differential pressure can be generated with the same responsiveness as that when any pump leakage is not present. Therefore, in the vehicular brake control device for controlling the dynamic behavior of the vehicle, the dynamic behavior can be controlled similarly to a case where any pump leakage is not present with the pump leakage being added thereto by generating the target differential pressure by the differential pressure control valve. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle brake control device that calculates a brake fluid leak amount (hereinafter referred to as a pump leak amount) in a pump provided in a hydraulic circuit and drives the pump to compensate for the leak. is there.

  Conventionally, Patent Document 1 describes that a pump leakage amount is calculated in a hydraulic pump drive used in a propulsion device such as an industrial heavy machine. Specifically, the leakage amount is directly calculated by calculating the leakage amount at the pump from the expected flow rate when the motor is driven and the measured actual flow rate. The pump is driven so as to compensate for the leakage.

  Patent Document 2 discloses a coolant pump device that can calculate the amount of leakage in the pump. In this device, the motor rotational speed when the specified pressure is reached in the initial stage of operation is set as the initial rotational speed, and the motor rotational speed of the motor rotational speed when the specified pressure is reached after aged deterioration is compared with the initial rotational speed. If the difference is equal to or greater than the predetermined rotation speed, it is detected that a pump leak has occurred.

JP 2000-158977 A JP 2004-338016 A

  However, since the apparatus described in Patent Document 1 directly calculates the pump leakage amount, it is necessary to detect the actual flow rate when the pump is driven. A configuration that is not provided is required.

  In the device described in Patent Document 2, pump leakage is detected in accordance with the difference between the initial rotational speed until the specified pressure is reached and the motor rotational speed after aging deterioration. Factors caused by individual differences in pumps become dominant. For this reason, even if the occurrence of pump leakage can be detected after aging, it is not sufficient to compensate for the amount of pump leakage that depends on individual differences in pumps.

  Moreover, it has been confirmed by experiments by the present inventors that the amount of pump leakage does not always become constant but changes depending on the pressure to be set. Specifically, a differential pressure is formed between a master cylinder (hereinafter referred to as M / C) and a wheel cylinder (hereinafter referred to as W / C) using a differential pressure control valve as in a vehicle brake control device. In the case where the differential pressure is changed according to the vehicle behavior control, the pump leakage amount changes according to the target differential pressure. For this reason, even if the amount of pump leakage is detected by simply comparing the motor rotation speed when the specified pressure is reached after aging with the initial rotation speed, the result does not necessarily correspond to the desired target differential pressure. It cannot be applied to vehicle behavior control.

  In view of the above points, the present invention provides a vehicle brake control device that controls the movement behavior of a vehicle by generating a target differential pressure using a differential pressure control valve, thereby reducing a pump leakage amount without requiring a flow sensor. In consideration of this, it is an object of the present invention to enable operation behavior control similar to that in the case where there is no pump leakage.

  In order to achieve the above object, in the first aspect of the present invention, the target differential pressure of the differential pressure control valve (16, 36) corresponds to the check point for learning the pump leak in the motor rotation speed increasing means (240). The differential pressure control valve (16, 36) is set to the differential pressure state by setting the specified differential pressure, and the pump (19, 39) causes the brake fluid to be discharged by driving the motor (60). And the motor rotation speed is gradually increased. Further, the W / C pressure and rotation speed detection means (220) calculated by the hydraulic pressure detection means (230) when the motor (60) is gradually increased by the rotation speed difference calculation means (250, 260). ) Is monitored, and the motor speed when the W / C pressure reaches the specified pressure and the default corresponding to the motor speed that is assumed to reach the specified pressure when there is no pump leakage. The rotation speed difference which is the difference from the value is calculated. Further, in the storage means (270), the rotation speed difference calculated by the rotation speed difference calculation means (250, 260) is used as the pump leakage motor rotation speed at the specified pressure, and the pump leakage motor rotation speed is used as a check point. When it is obtained for each corresponding specified differential pressure, the pump leakage motor rotational speed is stored in association with the specified differential pressure corresponding to the check point. Then, when there is a drive request for the motor (60) in the motion behavior control by the target rotation speed setting means (320, 340), the pump leakage motor rotation speed with respect to the specified differential pressure stored in the storage means (270). Based on this relationship, the pump leakage motor rotational speed corresponding to the target differential pressure set in the motion behavior control is obtained, and the target rotation of the motor (60) when the motion behavior control is executed based on the pump leakage motor rotational speed It is characterized by setting a number.

  In this way, while generating the specified differential pressure by the differential pressure control valve (16, 36), the pump leakage motor rotation speed corresponding to each specified differential pressure is obtained, and the relationship between the pump leakage motor rotation speed and the specified differential pressure is stored. Like to do. When the motor (60) is driven by the motion behavior control using the relationship of the pump leakage motor rotation speed with respect to the specified differential pressure, the motor (60) is driven at the target rotation speed in consideration of pump leakage. I have to. Therefore, even if pump leakage occurs, it is possible to generate the target differential pressure with the same responsiveness as when pump leakage does not occur. As a result, in the vehicle brake control device for controlling the movement behavior of the vehicle by generating the target differential pressure by the differential pressure control valve (16, 36), the pump leakage amount is taken into account even if the flow sensor is not required. Thus, it is possible to perform the same operation behavior control as when there is no pump leakage.

  In the invention according to claim 2, the specified differential pressure generating means (440) sets the target differential pressure of the differential pressure control valve (16, 36) to the specified differential pressure corresponding to the check point for learning the pump leakage. The differential pressure control valve (16, 36) is brought into a differential pressure state, and the motor (60) is driven to maximize the amount of brake fluid discharged by the pump (19, 39). 16, 36) to generate a specified differential pressure. Further, the motor rotational speed reduction means (450) gradually reduces the motor rotational speed while the specified differential pressure is generated, and the rotational speed difference calculation means (460) calculates the hydraulic pressure detection means (430). The W / C pressure and the motor speed detected by the rotation speed detection means (420) are monitored, and the motor speed when the W / C pressure drops from the specified pressure and the specified pressure when there is no pump leakage The rotational speed difference, which is the difference from the default value corresponding to the motor rotational speed that is assumed to decrease from the above, is calculated. Further, in the storage means (470), the rotation speed difference calculated by the rotation speed difference calculation means (460) is used as the pump leakage motor rotation speed at the specified pressure, and the pump leakage motor rotation speed corresponds to the check point. When it is obtained for each specified differential pressure, the number of revolutions of the pump leakage motor is stored in association with the specified differential pressure corresponding to the check point. Then, when there is a drive request for the motor (60) in the motion behavior control by the target rotation speed setting means (320, 340), the pump leakage motor rotation speed with respect to the specified differential pressure stored in the storage means (470). Based on this relationship, the pump leakage motor rotational speed corresponding to the target differential pressure set in the motion behavior control is obtained, and the target rotation of the motor (60) when the motion behavior control is executed based on the pump leakage motor rotational speed It is characterized by setting a number.

  In this way, the pump leakage motor rotational speed is obtained by decreasing the motor rotational speed while generating the specified differential pressure by the differential pressure control valve (16, 36), and the pump leakage motor rotational speed with respect to the specified differential pressure is determined. I try to remember the relationship. When the motor (60) is driven by the motion behavior control using the relationship of the pump leakage motor rotation speed with respect to the specified differential pressure, the motor (60) is driven at the target rotation speed in consideration of pump leakage. I have to. Therefore, even if pump leakage occurs, it is possible to generate the target differential pressure with the same responsiveness as when pump leakage does not occur. As a result, in the vehicle brake control device for controlling the movement behavior of the vehicle by generating the target differential pressure by the differential pressure control valve (16, 36), the pump leakage amount is taken into account even if the flow sensor is not required. Thus, it is possible to perform the same operation behavior control as when there is no pump leakage.

  For example, as described in claim 3, the target rotational speed setting means (320, 340) adds the pump leakage motor rotational speed to the indicated rotational speed of the motor rotational speed instructed by the driving behavior control. The value can be set as the target rotational speed.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

It is a figure showing the whole brake control device 1 composition concerning a 1st embodiment of the present invention. It is the flowchart which showed the detail of the motor control process. 6 is a timing chart of motor rotation speed and system hydraulic pressure during leakage learning. It is the flowchart which showed the detail of the leakage learning control process. It is the characteristic figure which showed an example of the relationship of the pump leak motor rotation speed with respect to the regulation differential pressure when performing pump leak learning. It is the flowchart which showed the detail of the motor target rotation speed calculation process. It is a timing chart of the motor rotation speed and the hydraulic pressure in the system during leakage learning of the second embodiment of the present invention. It is the flowchart which showed the detail of the leakage learning control process.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 shows an overall configuration of a vehicle brake control device 1 according to a first embodiment of the present invention. In this embodiment, in this vehicle brake control device 1, by performing motor control, the amount of pump leakage is compensated so that the movement behavior of the vehicle can be controlled as in the case where there is no pump leakage. First, the details of the vehicle brake control device 1 according to the present embodiment will be described.

  In FIG. 1, when the driver depresses the brake pedal 11, the pedaling force is boosted by the booster 12, and the master pistons 13a and 13b disposed in the M / C 13 are pressed. As a result, the same M / C pressure is generated in the primary chamber 13c and the secondary chamber 13d defined by the master pistons 13a and 13b. The M / C pressure is transmitted to each of the W / Cs 14, 15, 34, and 35 through the brake fluid pressure control actuator 50.

  Here, the M / C 13 includes a master reservoir 13e having a passage communicating with each of the primary chamber 13c and the secondary chamber 13d.

  The brake fluid pressure control actuator 50 has a first piping system 50a and a second piping system 50b. The first piping system 50a controls the brake fluid pressure applied to the left front wheel FL and the right rear wheel RR, and the second piping system 50b controls the brake fluid pressure applied to the right front wheel FR and the left rear wheel RL.

  Since the 1st piping system 50a and the 2nd piping system 50b are the same structures, below, the 1st piping system 50a is explained and explanation is omitted about the 2nd piping system 50b.

  The first piping system 50a transmits the M / C pressure described above to the W / C 14 provided on the left front wheel FL and the W / C 15 provided on the right rear wheel RR, and generates a W / C pressure. A pipe A is provided.

  Moreover, the pipe line A is provided with the 1st differential pressure control valve 16 which can be controlled to a communication state and a differential pressure state. The valve position of the first differential pressure control valve 16 is adjusted so that the first differential pressure control valve 16 is in a communicating state during normal braking (when vehicle behavior control is not executed) when the driver operates the brake pedal 11. When a current is passed through the solenoid coil provided in the one differential pressure control valve 16, the valve position is adjusted so that the larger the current value, the larger the differential pressure state.

  When the first differential pressure control valve 16 is in the differential pressure state, only when the brake fluid pressure on the W / C 14, 15 side is higher than the M / C pressure by a predetermined level or more, the M / The brake fluid is allowed to flow only to the C13 side. For this reason, the W / C 14, 15 side is always maintained so as not to be higher than the predetermined pressure by the M / C 13 side.

  The pipe A is branched into two pipes A1 and A2 on the W / C 14 and 15 side downstream of the first differential pressure control valve 16. The pipeline A1 is provided with a first pressure increase control valve 17 that controls the increase of the brake fluid pressure to the W / C 14, and the pipeline A2 is a first pressure that controls the increase of the brake fluid pressure to the W / C 15. A two pressure increase control valve 18 is provided.

  The first and second pressure increase control valves 17 and 18 are constituted by two-position solenoid valves that can control the communication / blocking state.

  The first and second pressure-increasing control valves 17 and 18 are in communication when the control current to the solenoid coils provided in the first and second pressure-increasing control valves 17 and 18 is zero (when no power is supplied). Thus, when the control current is supplied to the solenoid coil (when energized), the normally open type is controlled to be cut off.

  In the pipeline A, the first and second pressure increase control valves 17 and 18 and the pipeline B serving as a pressure-reducing pipeline connecting the pressure regulating reservoir 20 between the W / Cs 14 and 15 are controlled in communication / blocking states. The 1st pressure reduction control valve 21 and the 2nd pressure reduction control valve 22 which are comprised by the 2 position solenoid valve which can be each arrange | positioned. The first and second pressure reducing control valves 21 and 22 are normally closed.

  A conduit C serving as a reflux conduit is disposed between the pressure regulating reservoir 20 and a conduit A serving as a main conduit. The pipe C is provided with a self-priming pump 19 driven by a motor 60 that sucks and discharges brake fluid from the pressure regulating reservoir 20 toward the M / C 13 side or the W / C 14, 15 side. The motor 60 is driven by controlling energization to a motor relay (not shown).

  A conduit D serving as an auxiliary conduit is provided between the pressure regulating reservoir 20 and the M / C 13. The brake fluid is sucked from the M / C 13 by the pump 19 through the pipeline D and discharged to the pipeline A, so that the brake fluid is supplied to the W / C 14 and 15 side during vehicle behavior control. The W / C pressure of the wheel is increased. In addition, although the 1st piping system 50a was demonstrated here, the 2nd piping system 50b is also the same structure, The 2nd piping system 50b is also provided with the structure similar to each structure with which the 1st piping system 50a was equipped. Yes. Specifically, the second differential pressure control valve 36 corresponding to the first differential pressure control valve 16, the third and fourth pressure increase control valves 37, 38 corresponding to the first and second pressure increase control valves 17, 18. Corresponding to the third and fourth decompression control valves 41 and 42 corresponding to the first and second decompression control valves 21 and 22, the pump 39 corresponding to the pump 19, the reservoir 40 corresponding to the reservoir 20, and the pipelines A to D There are pipelines EH to do.

  The brake ECU 70 is a part that controls the control system of the vehicle brake control device 1, and is configured by a known microcomputer including a CPU, a ROM, a RAM, an I / O, and the like, and according to a program stored in the ROM or the like. While performing various calculations, various vehicle behavior control is performed. For example, the detection signals of the wheel speed sensors 71 to 74 provided in the respective wheels FL to RR are inputted, the wheel speeds of the respective wheels FL to RR are calculated, and the estimated vehicle body speed and the slip ratio are calculated by known methods. Then, anti-skid control (ABS control) is executed based on the calculated slip ratio. The brake ECU 70 also receives detection signals from a steering angle sensor, a yaw rate sensor, a lateral G (lateral acceleration) sensor, and the like (not shown), and from the actual yaw rate, the steering angle, and the estimated vehicle body speed calculated from the detection signals of the yaw rate sensor. Side slip prevention control can also be executed based on the deviation from the target yaw rate, which is the yaw rate in an ideal turning state without slip.

  For example, when the skid prevention control is executed, the target differential pressure is set by the first and second differential pressure control valves 16 and 36 while the motor 60 is driven to perform the suction and discharge operation of the brake fluid by the pumps 19 and 39. In addition, among the various pressure-increasing control valves 17, 18, 37, 38, the one corresponding to the control target wheel is set in the communication state, and the one corresponding to the non-control target wheel is set in the cutoff state, so that In contrast, a W / C pressure is generated. Thus, a desired braking force is generated, and a side slip is prevented by suppressing a yaw moment generated in the vehicle.

  In the present embodiment, the brake ECU 70 inputs a detection signal of an encoder (not shown) provided in the motor 60 to calculate the motor rotation speed, or inputs detection signals of the pressure sensors 75 and 76 to obtain W / W. The C pressure is calculated, and the pump leakage amount is calculated based on the calculated motor rotation speed and W / C pressure.

  Next, a motor control process executed by the brake ECU 70 provided in the vehicle brake control device 1 configured as described above will be described.

  In the motor control process, a pump leakage learning process, a motor target rotation speed calculation process, and the like are performed. The pump leak learning process is a process performed to learn pump leaks due to individual differences between the pumps 19 and 39 when the vehicle brake control device 1 is mounted on a vehicle. Further, the motor target rotation speed calculation process performs motor control based on the pump leakage characteristics learned by the pump leakage learning process, and the discharge amount of the brake fluid from the pumps 19 and 39 is the same as when there is no pump leakage. This is a process for compensating for the above. By these pump leakage learning processing and motor target rotation number calculation processing, the motor rotation number is corrected in accordance with the pump leakage amount, and the pumps 19 and 39 can perform the same discharge operation as when there is no pump leakage amount.

  FIG. 2 is a flowchart showing details of the motor control process. This process is executed every predetermined calculation cycle when an ignition switch (not shown) is turned on.

  First, in step 100, general initialization processing such as flag reset is performed on the brake ECU 70, and then the processing proceeds to step 110 to perform pump leakage learning processing. A method of performing this leakage learning will be described with reference to a timing chart of the motor rotation speed and the hydraulic pressure in the system during the leakage learning shown in FIG. The in-system hydraulic pressure indicates the W / C pressure generated in each of the first and second piping systems 50a and 50b.

  Leakage learning is performed based on the relationship between the differential pressure generated by the first and second differential pressure control valves 16 and 36 and the motor speed required to reach the differential pressure.

  That is, since the first and second differential pressure control valves 16 and 36 generate a differential pressure by the orifice effect between the valve seat and the valve body, the first and second differential pressure control valves 16 and 36 On the other hand, even if an attempt is made to generate a target differential pressure by causing an instruction current corresponding to the target differential pressure to flow, the target differential pressure cannot be generated unless the motor speed (rotational speed) reaches a certain level. There is a characteristic. Since the brake fluid discharge amount differs depending on whether the pump leaks or not at the same motor speed, a desired differential pressure is generated by the first and second differential pressure control valves 16 and 36. Therefore, the motor rotation speed required for this is different.

  Specifically, as shown in FIG. 3, a current is supplied to the first and second differential pressure control valves 16 and 36 to generate a target differential pressure, and the pumps 19 and 39 are rotated by rotating the motor 60. Is driven, the actual system hydraulic pressure gradually increases as the motor speed increases, and the system hydraulic pressure reaches the target differential pressure at a certain motor speed. At this time, looking at the hydraulic pressure in the system, the motor speed required to reach the target differential pressure when there is no pump leakage (broken line in the figure) and when there is pump leakage (solid line in the figure) When there is a pump leak, the number of motor revolutions required is greater than when there is no pump leak.

  For this reason, when there is no pump leakage, the motor rotational speed when the target differential pressure is reached is stored as a default value, and the motor rotational speed when the target differential pressure is reached during leakage learning is detected and Compare. As a result, even if there is a pump leak due to individual differences between the pumps 19 and 39, the motor speed required to achieve the target differential pressure in each of the pumps 19 and 39 (hereinafter referred to as the pump leak motor speed) is reduced. Obtainable. And by calculating | requiring such a pump leak motor rotation speed for several check points, ie, every predetermined differential pressure which wants to check a pump leak motor rotation speed, the relationship of the pump leak motor rotation speed with respect to a predetermined differential pressure can be obtained. . Based on such a leakage learning method, the leakage learning control process of the present embodiment is performed.

  FIG. 4 is a flowchart showing details of the leakage learning control process. Details of the leakage learning control process will be described with reference to this figure.

  First, in step 200, it is determined whether or not the sensor assembly check state is set. That is, it is determined whether or not all the various elements constituting the vehicle brake control device 1 are assembled to the vehicle. For example, when pump leakage learning is performed after assembling all the elements constituting the vehicle brake control device 1 to the vehicle, the operator prepares in a memory such as a ROM of the brake ECU 1 during the learning time. The specified check flag is set. Therefore, by confirming that this check flag is set, it is possible to determine whether or not it is in the sensor assembly check state.

  If an affirmative determination is made in the sensor assembly check state, the process proceeds to step 210 to determine whether or not the pump leakage learning has been performed. This determination is performed by confirming the execution completion flag provided in a memory such as a ROM in the brake ECU 70 when learning is completed in step 290 described later. Is called. If a negative determination is made in step 200 or step 210, it is not the leakage learning timing, so the processing is terminated as it is. If both the determination at step 200 and step 210 is affirmative, leakage learning is performed.

  Specifically, first, in step 220, sensor information reading processing is performed. Here, the detection signal from the encoder provided in the motor 60 and the detection signals of the pressure sensors 75 and 76 are read. Then, the process proceeds to step 230, and in-system hydraulic pressure calculation is performed. Specifically, the W / C pressures of the first and second piping systems 50a and 50b are calculated based on the detection signals of the pressure sensors 75 and 76 read in step 110d.

  Next, the process proceeds to step 240, where the specified differential pressure of the check point to be leaked is set as the target differential pressure of the first and second differential pressure control valves 16, 36, and the pump 19, 39 is driven. Further, the motor rotation speed is gradually increased with a specified gradient by increasing the current flowing to the motor 60 (period a in FIG. 3). Subsequently, the process proceeds to step 250, where the in-system hydraulic pressure and the motor rotational speed when the motor rotational speed is gradually increased with a specified gradient are monitored (period b in FIG. 3). Then, the motor rotational speed when the in-system hydraulic pressure becomes the specified differential pressure is calculated.

  Further, the process proceeds to step 260, where the default value stored in the memory such as ROM, that is, the motor rotational speed when the specified differential pressure is reached when there is no pump leakage and the specified differential pressure calculated in step 250 is reached. Is calculated (see c in FIG. 3). Then, the process proceeds to step 270, where the difference in motor speed calculated in step 260 is stored as a pump leakage motor speed in a memory such as a ROM in association with the specified differential pressure as the current check point (d in FIG. 3). In addition, a flag corresponding to the check point at which leakage learning has been performed this time is set. Thereby, the pump leakage learning is completed for the specified differential pressure that is the current check point.

  Thereafter, the process proceeds to step 280, where it is determined whether or not the pump leakage learning is completed for all check points. Here, if the flags corresponding to all checkpoints have not been set, the process returns to step 220 again to perform leak learning for checkpoints that are not set. In addition, selection of the check point which performs pump leak learning can be made to select in order from a thing with a small prescription | regulation pressure, for example.

  When the pump leakage learning is completed for all check points and an affirmative determination is made in step 280, the process proceeds to step 290, an execution completion flag indicating that the pump leakage learning is completed is set, and the process ends.

  FIG. 5 is a characteristic diagram showing an example of the relationship between the pump leakage motor rotation speed and the specified differential pressure when the pump leakage learning is performed in this manner. As shown in this figure, by plotting the relationship between the specified differential pressure at each check point obtained by leak learning and the pump leakage motor speed, and connecting or complementing them with a straight line or curve, the specified differential pressure is obtained. The pump leakage motor rotational speed characteristic with respect to the pressure can be obtained.

  When the pump leakage learning process is completed in this way, the process proceeds to step 120, where start / end determination of motion behavior control is performed. Specifically, as driving behavior control, while the first and second differential pressure control valves 16 and 36 are in a differential pressure state, the motor 60 is driven and the brake fluid 19 is discharged by the pumps 19 and 39. It is determined whether the control for generating the target differential pressure is started between C13 and W / C 14, 15, 34, 35, or before or after the start.

  For example, as the motion behavior control, the above-described skid prevention control can be exemplified. In the brake ECU 70, when the functional unit that executes the skid prevention control satisfies the start condition of the skid prevention control (for example, the deviation between the actual yaw rate and the target yaw rate exceeds a threshold), the motion behavior control is started. The flag indicating that the motion behavior control has been started is reset when an end condition (for example, the vehicle has stopped) is satisfied. Therefore, the above determination can be made based on whether or not a flag indicating that the motion behavior control has been started is set.

  If an affirmative determination is made here, the routine proceeds to step 130, where a motor target rotation speed calculation process is performed. FIG. 6 is a flowchart showing details of the motor target rotation number calculation process. The details of the motor target rotation speed calculation process will be described with reference to this figure.

  First, in step 300, motor drive request determination is performed. Specifically, it is determined whether or not there is a request to drive the motor 60 when the motion behavior control has been started. For example, this determination is made based on whether or not motor driving is requested by the motion behavior control. Accordingly, it can be confirmed that the differential pressure is formed by the discharge operation of the pumps 19 and 39 by driving the motor 60 and the driving of the first and second differential pressure control valves 16 and 36. If an affirmative determination is made here, the routine proceeds to step 310.

  In step 310, it is determined whether or not the pump leakage has been learned. Here, if the execution completion flag is set in step 290 of FIG. 4 described above, a positive determination is made, and if it is not set, a negative determination is made. If an affirmative determination is made in step 310, the process proceeds to step 320, and the first set in the motion behavior control based on the pump leakage motor rotation speed characteristic with respect to the specified differential pressure stored by the pump leakage learning. Then, the number of revolutions of the pump leakage motor corresponding to the target differential pressure of the second differential pressure control valves 16 and 36 is read out. On the other hand, if a negative determination is made at step 310, the routine proceeds to step 330, where the specified rotational speed is set as the pump leakage motor rotational speed. The specified rotational speed here indicates the rotational speed of the pump leakage motor assumed in the product standard, but if no pump leakage learning is performed, the pump leakage motor is assumed assuming no pump leakage. The rotational speed may be set to zero.

  When the pump leakage motor rotational speed is determined, the process proceeds to step 340, where the motor target rotational speed for actually driving the motor 60 is set. That is, a value obtained by adding the pump leakage motor rotation speed determined in steps 320 and 330 to the motor rotation speed (hereinafter referred to as the instruction rotation speed) instructed by the motion behavior control (instruction rotation speed + pump leakage motor rotation speed). ) And set this as the motor target speed. As a result, the motor target rotational speed when the driving behavior control is executed and the motor 60 is driven is determined. If a negative determination is made in step 300, the motor 60 is not being driven, so the routine proceeds to step 350 where the motor target rotational speed is set to 0 and the process is terminated.

  When the motor target rotational speed calculation process is completed in this way, the process proceeds to step 140, and the motor 60 is driven in accordance with the request for the driving behavior control. At this time, by driving the motor 60 at the motor target rotation speed calculated in the motor target rotation speed calculation process in step 130, the motor 60 can be driven at the motor rotation speed considering the pump leakage. Therefore, even if pump leakage occurs, it is possible to generate the target differential pressure with the same responsiveness as when pump leakage does not occur. Thereafter, the processing after step 110 is repeated.

  As described above, according to the motor control process by the vehicle brake control device 1 of the present embodiment, the first and second differential pressure control valves 16 and 36 generate the specified differential pressure, The corresponding pump leakage motor rotational speed is obtained, and the relationship between the pump leakage motor rotational speed and the specified differential pressure is stored. When the motor 60 is driven by the motion behavior control using the relationship of the pump leakage motor rotation speed with respect to the specified differential pressure, the motor 60 is driven at the motor target rotation speed in consideration of pump leakage. . Therefore, even if pump leakage occurs, it is possible to generate the target differential pressure with the same responsiveness as when pump leakage does not occur. As a result, the vehicle brake control device 1 that controls the movement behavior of the vehicle by generating the target differential pressure by the first and second differential pressure control valves 16 and 36 can eliminate the need for a flow rate sensor. It is possible to perform operation behavior control similar to the case where there is no pump leakage in consideration of the leakage amount.

(Second Embodiment)
A second embodiment of the present invention will be described. In the present embodiment, the pump leakage learning process is changed with respect to the first embodiment, and the other aspects are the same as those in the first embodiment. Therefore, only different portions from the first embodiment will be described.

  In the pump leakage learning process of the first embodiment, the pump leakage learning is performed by gradually increasing the motor rotation speed and obtaining the motor rotation speed required to obtain the specified differential pressure. On the other hand, in the present embodiment, the motor rotational speed is increased from the beginning until the brake fluid discharge amount by the pumps 19 and 39 is maximized, and then the motor rotational speed is gradually decreased to reduce the prescribed difference. Pump leakage learning is performed based on the motor speed when the pressure cannot be maintained.

  That is, as described above, the first and second differential pressure control valves 16 and 36 generate the differential pressure by the orifice effect between the valve seat and the valve body. Even if an attempt is made to generate the target differential pressure with the valves 16 and 36 in the differential pressure state, there is a characteristic that the target differential pressure cannot be generated unless the motor rotation speed (rotational speed) reaches a certain level. In addition, since there is a difference in the amount of brake fluid discharged between the case where there is a pump leak and the case where there is no pump leakage, the first and second differential pressure control valves 16 and 36 generate a target differential pressure. The number of motor revolutions required for this is different. Therefore, since the motor speed when the specified differential pressure can be maintained also changes depending on whether there is a pump leak or not, leak learning can be performed based on the motor speed difference.

  FIG. 7 is a timing chart of the motor rotation speed and the hydraulic pressure in the system during leak learning according to the present embodiment. As shown in this figure, a current is supplied to the first and second differential pressure control valves 16 and 36 to generate a specified differential pressure, and the pumps 19 and 39 are driven by rotating the motor 60. At this time, the motor 60 is fully driven so that the amount of brake fluid discharged from the pumps 19 and 39 is maximized. Then, the motor rotational speed is gradually decreased by gradually decreasing the target rotational speed of the motor 60 with a specified gradient. As a result, the hydraulic pressure in the system starts to drop from the specified differential pressure when a certain motor speed is reached. The motor rotation speed at the beginning of the drop is larger in the case where there is a pump leak than in the case where there is no pump leak. In other words, the motor rotational speed at the beginning of the drop is the motor rotational speed required to maintain the specified differential pressure. When there is a pump leak, the motor rotational speed is higher than when there is no pump leak. growing.

  Therefore, the motor 60 is driven to maximize the discharge amount of the brake fluid by the pumps 19 and 39, and the specified differential pressure is generated by the first and second differential pressure control valves 16 and 36. The rotational speed is reduced to obtain the motor rotational speed when the hydraulic pressure in the system drops. Then, when there is no pump leakage, the motor rotation speed when the system hydraulic pressure drops from the specified differential pressure is stored as a default value, and the motor rotation speed when the system hydraulic pressure drops during leak learning is detected and defaulted. Compare with the value. As a result, even if there is a pump leak due to individual differences between the pumps 19 and 39, the motor speed required to achieve the target differential pressure in each of the pumps 19 and 39 (hereinafter referred to as the pump leak motor speed) is reduced. Obtainable. Then, by obtaining such a pump leakage motor rotation speed for each of a plurality of check points, that is, for each specified differential pressure for which the pump leakage motor rotation speed is desired to be checked, a pump leakage motor rotation speed characteristic with respect to the specified differential pressure can be obtained. Based on such a leakage learning method, the leakage learning control process of the present embodiment is performed.

  FIG. 8 is a flowchart showing details of the leakage learning control process of the present embodiment. Details of the leakage learning control process will be described with reference to this figure.

  First, in steps 400 and 410, it is determined whether or not the sensor assembly check state has been established and whether or not the pump leakage learning has been performed by the same method as in steps 200 and 210 of FIG. If both step 400 and step 410 are positively determined, leakage learning is performed.

  Specifically, first, in steps 420 and 430, the sensor information reading process and the in-system hydraulic pressure calculation are performed by the same method as in steps 220 and 230 in FIG.

  In step 440, the target differential pressure of the first and second differential pressure control valves 16 and 36 is set to a specified differential pressure at a check point where leakage learning is to be performed, and the motor 60 is rotated so that the brake fluid generated by the pumps 19 and 39 So that the discharge amount becomes maximum. As a result, the specified differential pressure is generated by the first and second differential pressure control valves 16 and 36 (period a in FIG. 7).

  Next, in step 450, the motor rotational speed is gradually decreased with a specified gradient by gradually decreasing the target rotational speed of the motor 60 (period b in FIG. 7). At this time, the first and second differential pressure control valves 16 and 36 keep the target differential pressure at the specified differential pressure.

  Subsequently, the process proceeds to step 460, where it is detected that the in-system oil pressure has started to drop by monitoring the in-system oil pressure and the motor speed when the motor rotation speed is gradually decreased at a specified gradient. For example, by determining whether or not the difference between the specified differential pressure and the in-system hydraulic pressure exceeds a threshold value, it is possible to detect the start of the drop in the in-system hydraulic pressure. Then, the motor rotation speed when the hydraulic pressure in the system starts to drop is calculated, and the default value stored in the memory such as the ROM, that is, the hydraulic pressure in the system starts to drop from the specified differential pressure when there is no pump leakage. The difference from the motor rotation speed is calculated (see c in FIG. 7).

  Further, the process proceeds to step 470, where the difference in the motor speed calculated in step 460 is stored in a memory such as a ROM as the pump leak motor speed (see d in FIG. 7), and the current leak learning is checked. Set the flag corresponding to the point. Thereby, the pump leakage learning is completed for the specified differential pressure that is the current check point.

  Thereafter, in Steps 480 and 490, as in Steps 280 and 290 of FIG. 4, it is determined whether or not the pump leakage learning is completed for all check points. If completed, it indicates that the pump leakage learning is completed. The execution completion flag is set and the process is terminated.

  As described above, according to the motor control process by the vehicle brake control device 1 of the present embodiment, the motor rotational speed is gradually increased while the specified differential pressure is generated by the first and second differential pressure control valves 16 and 36. The pump leakage motor rotational speed is obtained by decreasing the pressure to the predetermined value, and the relationship between the pump leakage motor rotational speed and the specified differential pressure is stored. When the motor 60 is driven by the motion behavior control using the relationship of the pump leakage motor rotation speed with respect to the specified differential pressure, the motor 60 is driven at the motor target rotation speed in consideration of pump leakage. . Therefore, even if pump leakage occurs, it is possible to generate the target differential pressure with the same responsiveness as when pump leakage does not occur. As a result, the vehicle brake control device 1 that controls the movement behavior of the vehicle by generating the target differential pressure by the first and second differential pressure control valves 16 and 36 can eliminate the need for a flow rate sensor. It is possible to perform operation behavior control similar to the case where there is no pump leakage in consideration of the leakage amount.

(Other embodiments)
In the above embodiment, an example of the piping structure constituting the vehicle brake control device 1 has been shown. However, the target differential pressure is generated based on the brake fluid discharge operation by the pump while the differential pressure control valve is in the differential pressure state. Any configuration may be used as long as it has such a configuration. For example, like a brake-by-wire, the pedal force for the brake pedal is generated by a stroke simulator, and the brake fluid pressure is electrically generated in the M / C separated from the brake pedal in accordance with the pedal force. The present invention can also be applied to a configuration that generates pressure.

  In addition, the side slip prevention control has been described as an example of the vehicle motion behavior control. However, the motion behavior control may generate the differential pressure by driving the pump while the differential pressure control valve is in the differential pressure state. For example, the present invention can be applied to anything.

  The steps shown in each figure correspond to means for executing various processes. That is, the part that executes the processes of steps 220 and 420 is the rotation speed detecting means, the part that executes the processes of steps 230 and 430 is the hydraulic pressure detecting means, the part that executes the process of step 240 is the motor speed increasing means, and the step 250, 260, and 460 are executed by the rotational speed difference calculating means, steps 270 and 470 are executed by the storage means, and steps 320 and 340 are executed by the target rotational speed setting means. The part that executes the process of 440 corresponds to the specified differential pressure generating means, and the part that executes the process of step 450 corresponds to the motor rotational speed reducing means.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle brake control apparatus, 11 ... Brake pedal, 13 ... M / C, 14, 15, 34, 35 ... W / C, 16, 36 ... 1st, 2nd differential pressure control valve, 19, 39 ... Pump , 60 ... motor, 70 ... brake ECU

Claims (3)

A wheel cylinder (14, 15, 34, 35) that receives a supply of brake fluid according to a driver's brake operation and generates a braking force on the wheels of the vehicle;
Pipelines (A, E) for supplying the brake fluid to the wheel cylinders (14, 15, 34, 35);
It is provided in the pipes (A, E) and is controlled to a differential pressure state by flowing a current according to a target differential pressure, and the master cylinder (13) side of the pipes (A, E) and the A differential pressure control valve (16, 36) for generating a target differential pressure between the wheel cylinder (14, 15, 34, 35) side;
A pump (19, 39) that discharges brake fluid to the wheel cylinder (14, 15, 34, 35) side of the differential pressure control valve (16, 36) in the pipe line (A, E); ,
A motor (60) for driving the pump (19, 39);
In the vehicle brake control device having control means (70) for controlling the motion behavior of the vehicle by controlling the motor (60) and the differential pressure control valve (16, 36),
The control means (70)
A rotation speed detecting means (220) for detecting a motor rotation speed which is a rotation speed of the motor (60);
Hydraulic pressure detection means (230) for detecting wheel cylinder pressure generated in the wheel cylinder (14, 15, 34, 35);
The target differential pressure of the differential pressure control valve (16, 36) is set to a specified differential pressure corresponding to one of a plurality of check points for learning the pump leakage, and the differential pressure control valve (16, 36) is set. Motor rotation speed increasing means for causing the pump (19, 39) to discharge brake fluid and gradually increasing the motor rotation speed while setting the differential pressure state and driving the motor (60) (240)
The wheel cylinder pressure calculated by the hydraulic pressure detecting means (230) and the motor detected by the rotational speed detecting means (220) when the motor is gradually increased by the motor rotational speed increasing means. The rotation speed is monitored, and the motor rotation speed when the wheel cylinder pressure reaches the specified pressure and a default value corresponding to the motor rotation speed assumed to reach the specified pressure when there is no pump leakage. A rotational speed difference calculating means (250, 260) for calculating a rotational speed difference as a difference;
The rotation speed difference calculated by the rotation speed difference calculation means (250, 260) is defined as the pump leakage motor rotation speed at the specified pressure, and the pump leakage motor rotation speed corresponds to each of the plurality of check points. Storage means (270) for storing the rotational speed of the pump leakage motor in association with the specified differential pressure corresponding to each of the plurality of checkpoints, when determined for each specified differential pressure;
When there is a drive request for the motor (60) in the motion behavior control, the motion behavior control is performed based on the relationship between the pump leakage motor rotational speed and the specified differential pressure stored in the storage means (270). The pump leakage motor rotational speed corresponding to the target differential pressure set in step S3 is obtained, and the target rotational speed of the motor (60) when executing the motion behavior control is set based on the pump leakage motor rotational speed. And a target rotational speed setting means (320, 340) for driving the motor (60). A wheel cylinder (14, 15, 34, 35) that receives a supply of brake fluid according to a driver's brake operation and generates a braking force on the wheels of the vehicle;
Pipelines (A, E) for supplying the brake fluid to the wheel cylinders (14, 15, 34, 35);
It is provided in the pipes (A, E) and is controlled to a differential pressure state by flowing a current according to a target differential pressure, and the master cylinder (13) side of the pipes (A, E) and the A differential pressure control valve (16, 36) for generating a target differential pressure between the wheel cylinder (14, 15, 34, 35) side;
A pump (19, 39) that discharges brake fluid to the wheel cylinder (14, 15, 34, 35) side of the differential pressure control valve (16, 36) in the pipe line (A, E); ,
A motor (60) for driving the pump (19, 39);
In the vehicle brake control device having control means (70) for controlling the motion behavior of the vehicle by controlling the motor (60) and the differential pressure control valve (16, 36),
The control means (70)
A rotational speed detecting means (420) for detecting a motor rotational speed which is a rotational speed of the motor (60);
Hydraulic pressure detecting means (430) for detecting wheel cylinder pressure generated in the wheel cylinder (14, 15, 34, 35);
The target differential pressure of the differential pressure control valve (16, 36) is set to a specified differential pressure corresponding to one of a plurality of check points for learning the pump leakage, and the differential pressure control valve (16, 36) is set. The differential pressure is controlled by the differential pressure control valve (16, 36) by setting the differential pressure state and driving the motor (60) to maximize the amount of brake fluid discharged by the pump (19, 39). A specified differential pressure generating means (440) for generating pressure;
Motor rotation speed reduction means (450) for gradually decreasing the motor rotation speed in a state where the specified differential pressure is generated;
The wheel cylinder pressure calculated by the hydraulic pressure detecting means (430) and the motor detected by the rotational speed detecting means (420) when the motor is gradually lowered by the motor rotational speed increasing means. The rotation speed is monitored, and the motor rotation speed when the wheel cylinder pressure decreases from the specified pressure and a default value corresponding to the motor rotation speed that is assumed to decrease from the specified pressure when there is no pump leakage. A rotational speed difference calculating means (460) for calculating a rotational speed difference as a difference;
The rotation speed difference calculated by the rotation speed difference calculation means (460) is defined as the pump leakage motor rotation speed at the specified pressure, and the pump leakage motor rotation speed corresponds to each of the plurality of check points. Storage means (470) for storing the pump leakage motor rotational speed in association with the prescribed differential pressure corresponding to each of the plurality of check points, when determined for each differential pressure;
When there is a drive request for the motor (60) in the motion behavior control, the motion behavior control is performed based on the relationship between the pump leakage motor rotation speed and the specified differential pressure stored in the storage means (470). The pump leakage motor rotational speed corresponding to the target differential pressure set in step S3 is obtained, and the target rotational speed of the motor (60) when executing the motion behavior control is set based on the pump leakage motor rotational speed. And a target rotational speed setting means (320, 340) for driving the motor (60).   The target rotational speed setting means (320, 340) sets, as the target rotational speed, a value obtained by adding the pump leakage motor rotational speed to the indicated rotational speed of the motor rotational speed instructed by the operation behavior control. The vehicle brake control device according to claim 1, wherein the vehicle brake control device is a vehicle brake control device.

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