JP2013248975A - Brake control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve brake feeling at ABS control.SOLUTION: Change of the brake fluid amount that inflow and outflow in/from an M/C is reduced by executing the pump discharge amount control processing in a brake ECU 70, and controlling the discharge amount by pumps 19 and 39 in controlling ABS. As a result, the brake feeling can be improved by reducing the width of the pedal vibration according to the change of the control mode (decompression control/holding control/control of increasing pressure) of the ABS control.

Description

  The present invention relates to an anti-lock brake (hereinafter referred to as a wheel lock) that suppresses wheel slip by controlling a brake fluid pressure (hereinafter referred to as W / C pressure) in a wheel cylinder (hereinafter referred to as W / C pressure) using a brake fluid pressure circuit. The present invention relates to a braking control device applied to a braking device provided with a control unit.

  Conventionally, the ABS control unit has a reservoir for storing brake fluid discharged from the W / C, and a pump for discharging the brake fluid in the reservoir to the master cylinder (hereinafter referred to as M / C) side. What is configured is known. Further, as a braking control device, there is known a device that controls a pump discharge amount so that brake fluid in a reservoir can be discharged to the M / C side within a certain time (see Patent Document 1). ). As a result, the technique disclosed in Patent Document 1 attempts to reduce the power consumption, vibration, and noise of the ABS control unit.

Japanese Patent Laid-Open No. 9-267636

  However, in the technique disclosed in Patent Document 1, the brake fluid in the reservoir is reduced by the pump when the W / C pressure in the ABS control is reduced (hereinafter referred to as pressure reduction control) or at the time of holding (hereinafter referred to as hold control). By discharging to the C side, the brake pedal is pushed back from the M / C side, or when the W / C pressure in the ABS control is increased (hereinafter referred to as pressure increase control), the brake fluid in the M / C is discharged. The brake pedal enters the M / C side by flowing into W / C. As a result, vibration of the operation amount of the brake pedal (hereinafter referred to as pedal vibration) is caused during the ABS control, and the brake feeling is lowered.

  An object of this invention is to provide the braking control apparatus which can improve the brake feeling at the time of ABS control in view of the said point.

  In order to achieve the above object, according to the first aspect of the present invention, in the brake control device applied to the brake device including the antilock brake control unit (50), the acquisition means (100) uses the brake operation member (11). ) And the M / C pressure that is the brake fluid pressure in the M / C (13), and the control means (140 to 160) obtains the operation quantity acquired by the acquisition means and The brake fluid discharge amount by the pump (19, 39) is controlled based on at least one of the M / C pressures.

  In this manner, the brake fluid discharge amount by the pump (19, 39) is controlled based on at least one of the operation amount and the M / C pressure during the anti-lock brake control, thereby flowing into and out of the M / C. It is possible to reduce the amount of brake fluid. Thereby, the vibration width of the operation amount of the brake operation member accompanying the change in the control mode of the antilock brake control (at the time of pressure reduction control / at the time of holding control / at the time of pressure increase control) can be reduced to improve the brake feeling. it can.

  According to the second aspect of the present invention, the setting means (115) determines at least one of the operation amount and the M / C pressure at the start of the antilock brake control as the operation amount and M in the antilock brake control. It is set as a reference value for at least one of the / C pressures, and the control means corresponds to the reference value set by the setting means, the operation amount acquired by the acquisition means, and the M / C pressure. It is characterized in that the amount of brake fluid discharged by the pump is controlled based on the difference from the value to be performed.

  Thus, based on the difference between the reference value and the acquired value corresponding to the reference value, based on either the operation amount of the brake operation member or the M / C pressure at the start of the antilock brake control, By controlling the amount of brake fluid discharged by the pump, the degree of divergence of the operation amount from the operation amount at the start of antilock brake control can be reduced to improve the brake feeling. In this case, as the difference increases toward the side where the brake operation member enters, the discharge amount is controlled so that the brake fluid discharge amount by the pump increases, and the difference is the side where the brake operation member is pushed back from the M / C side. It is preferable to control the discharge amount so that the brake fluid discharge amount by the pump decreases as the value increases. In this way, the degree of deviation of the operation amount of the brake operation member from the start point of the antilock brake control can be further reduced.

  When the road surface condition changes during the anti-lock brake control, the operation amount of the brake operation member corresponding to the road surface condition changes. Therefore, if the road surface condition changes during anti-lock brake control, the discharge amount of brake fluid by the pump is controlled with the above-mentioned reference value as the operation amount or M / C pressure at the start of anti-lock brake control. It is conceivable that the vibration width of the operation amount of the brake operation member becomes large.

  Therefore, in the invention according to claim 3, the degree of divergence between the reference value and the value corresponding to the reference value among the operation amount and M / C pressure acquired by the acquisition means is calculated by the derivation means (130). When the divergence degree derived by the derivation means is larger than the predetermined divergence degree by the deriving and updating means (135), the reference value is obtained from the operation amount and M / C pressure obtained by the obtaining means. Of these, updating is performed with a value corresponding to the reference value.

  In this way, when the deviation degree derived by the deriving means is larger than the predetermined deviation degree, the reference value is updated, and the reference value is set according to the road surface condition at that time. It is possible to suppress an increase in the vibration amplitude of the operation amount of the brake operation member due to the change in the road surface condition.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a figure which shows the cross-sectional structure of the braking device for vehicles concerning 1st Embodiment of this invention. It is the flowchart which showed the detail of the pump discharge amount control process. 5 is a timing chart of W / C pressure, motor rotation speed, and pedal stroke st when the motor rotation speed is varied as in the first embodiment of the present invention during ABS control. 6 is a timing chart showing how a reference pedal st value is updated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 shows an overall configuration of a vehicle braking device 1 according to a first embodiment of the present invention. The braking device 1 performs brake control such as ABS control.

  As shown in FIG. 1, a brake pedal 11 as a brake operation member that is depressed by a driver when a braking force is applied to the vehicle is connected to a booster 12 and an M / C 13, and the driver applies the brake pedal 11. When stepped on, the boosting device 12 boosts the pedaling force and presses the master pistons 13a and 13b disposed on the M / C 13. 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 13 is provided with a master reservoir 13e having passages communicating with the primary chamber 13c and the secondary chamber 13d. The master reservoir 13e supplies brake fluid into the M / C 13 through the passage, or stores excess brake fluid in the M / C 13.

  The M / C pressure generated in the M / C 13 is transmitted to each of the W / Cs 14, 15, 34, 35 through the brake fluid pressure control actuator 50. As a result, a brake pad (not shown) is pressed against the brake disc to generate a braking force.

  The brake fluid pressure control actuator 50 constitutes an ABS control unit, and includes 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. The brake fluid pressure circuit of X piping is constituted by these two systems, the first and second piping systems 50a and 50b. In addition, although X piping system is mentioned as an example here, you may be the brake hydraulic circuit of other structures, such as front and rear piping.

  Hereinafter, the first and second piping systems 50a and 50b will be described. However, since the first piping system 50a and the second piping system 50b have substantially the same configuration, the first piping system 50a will be described here. The description of the second piping system 50b is omitted with reference to the first piping system 50a.

  The first piping system 50a includes a pipeline A serving as a main pipeline that transmits the above-described M / C pressure to the W / C 14 provided in the left front wheel FL and the W / C 15 provided in the right rear wheel RR. ing. Through this pipe A, W / C pressure is generated in each of the W / Cs 14 and 15.

  The pipe A is provided with a first differential pressure control valve 16. The first differential pressure control valve 16 controls the differential pressure generated between the upstream and downstream sides, that is, between the M / C 13 side and the W / C 14, 15 side. 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 communication state during a normal brake state or ABS control. When a current is passed through the solenoid coil in brake control such as skid prevention control, a differential pressure corresponding to the current value is generated, but it is not basically used during ABS control. Omitted.

  Further, the pipe A branches into two pipes A1 and A2 downstream of the first differential pressure control valve 16 on the W / C 14 and 15 side. One of the two pipes A1 and A2 is provided with a first pressure increase control valve 17 for controlling the increase of the brake fluid pressure to the W / C 14, and the other is an increase of the brake fluid pressure to the W / C 15. A second pressure increase control valve 18 is provided for controlling the pressure.

  The first and second pressure increase control valves 17 and 18 are constituted by two-position solenoid valves that can control the communication cut-off state, and currents to the solenoid coils provided in the first and second pressure increase control valves 17 and 18. When the supply is zero (when no power is supplied), the communication state is established, and when the current is supplied to the solenoid coil (when the current is supplied), a normally open type is formed. These first and second pressure-increasing control valves 17 and 18 may be used as on / off valves that switch the communication / blocking state by duty-controlling the current supply, or are generated between the upstream and downstream sides by controlling the energization amount. It may be used as a linear valve for controlling the differential pressure.

  Between the first and second pressure increase control valves 17 and 18 and the W / Cs 14 and 15 in the pipe line A, a pipe line B as a pressure reducing pipe line is provided. Is connected. Between the W / Cs 14 and 15 and the pressure regulating reservoir 20 in the pipeline B, a first pressure reduction control valve 21 and a second pressure reduction control valve 22 constituted by a two-position electromagnetic valve capable of controlling the communication / blocking state, Are arranged respectively. These first and second pressure reduction control valves 21 and 22 are normally closed, and when the current supply to the solenoid coils provided in the first and second pressure reduction control valves 21 and 22 is zero (non-energized) ) When the solenoid coil is supplied with current (when energized).

  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-feeding pump 19 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 pump 19 is driven by a motor 60, and by controlling the voltage application to the motor 60 by turning on and off the semiconductor switch 61a provided in the motor relay 61, the amount of brake fluid sucked and discharged by the pump 19 is controlled. The Specifically, in the present embodiment, the application of voltage to the motor 60 (current supply) is controlled by duty control of on / off of the semiconductor switch 61a to control the motor speed, and the pump 19 sucks brake fluid. The discharge amount is controlled.

  Further, 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 brake fluid control such as skid prevention control is performed on the W / C 14 and 15 side. And the W / C pressure of the target wheel can be increased.

  As described above, the second piping system 50b includes substantially the same components as the configuration of the first piping system 50a. Specifically, the first differential pressure control valve 16 corresponds to the second differential pressure control valve 36. The first and second pressure increase control valves 17 and 18 correspond to the third and fourth pressure increase control valves 37 and 38, respectively, and the first and second pressure increase control valves 21 and 22 correspond to the third and fourth values, respectively. This corresponds to the pressure reduction control valves 41 and 42. The pressure regulation reservoir 20 corresponds to the pressure regulation reservoir 40. The pump 19 corresponds to the pump 39. Further, the pipeline A, the pipeline B, the pipeline C, and the pipeline D correspond to the pipeline E, the pipeline F, the pipeline G, and the pipeline H, respectively. With the configuration as described above, a hydraulic piping structure in the brake hydraulic pressure control actuator 50 is configured.

  The braking device 1 is provided with a brake ECU 70. The brake ECU 70 corresponds to the vehicle braking control device of the present invention that controls the control system of the braking device 1, and is constituted by a known microcomputer including a CPU, a ROM, a RAM, an I / O, and the like. In accordance with the stored program, processing related to ABS control such as various calculations is executed.

  Specifically, the brake ECU 70 receives detection signals from the wheel speed sensors 71 to 74 provided to the wheels FL to RR and a detection signal from the pedal stroke sensor 75, and the wheel speeds and vehicle speeds of the wheels FL to RR. (Estimated vehicle body speed) is calculated and pedal stroke st is calculated. Note that the pedal stroke st is detected as a value that increases as the depression becomes large when the state before the brake pedal 11 is depressed is 0, or conversely, a value that increases as the depression is the most depressed and the depression becomes small. Can be detected as In either case, in the present embodiment, the former case will be described as an example.

  Further, the brake ECU 70 calculates a slip ratio expressed as a deviation of these based on the calculated vehicle speed and wheel speed, and the ABS control start condition indicates that the calculated slip ratio exceeds a predetermined threshold value. Then, ABS control is started. The brake ECU 70 sets a control mode according to the change in the slip ratio, and drives the pressure reducing control valves 16-18, 21, 22, 36-38, 41, 42 and the pumps 19, 39 according to the set control mode. The voltage application control to the motor 60 is executed to perform pressure reduction control, holding control, and pressure increase control. Thereby, the wheel slip is suppressed by controlling the W / C pressure, and the tendency of the wheels to lock is avoided. For example, in the pressure-reducing control, holding control, and pressure-increasing control of ABS control, the control valves corresponding to the wheels W / C 14, 15, 34, and 35 to be controlled are operated as follows.

  At the time of pressure reduction control, the first and second differential pressure control valves 16 and 36 are kept in communication, the first to fourth pressure increase control valves 17, 18, 37, and 38 are shut off, and the first to fourth pressure control is performed. The pressure reduction control valves 21, 22, 41, 42 are brought into a communication state. The pumps 19 and 39 are operated by driving the motor 60. As a result, the brake fluid in the pipelines A and E flows between the first and second reservoirs 20 between the first to fourth pressure increase control valves 17, 18, 37 and 38 and the W / C 14, 15, 34 and 35. , 40 is discharged. Then, the brake fluid is sucked and discharged by the pumps 19 and 39 and returned between the M / C 13 in the pipelines A and E and the first and second differential pressure control valves 16 and 36. As a result, the W / C pressures of the W / Cs 14, 15, 34, and 35 are reduced.

  In the holding control, the first and second differential pressure control valves 16 and 36 remain in communication, the first to fourth pressure increase control valves 17, 18, 37, and 38 are shut off, and the first to fourth pressure reduction valves. The control valves 21, 22, 41, 42 are also shut off. Thereby, W / C pressure of W / C14, 15, 34, and 35 is held.

  During the pressure increase control, the first and second pressure increase control valves 16 and 36 remain in communication, and the pressure difference generated by the first to fourth pressure increase control valves 17, 18, 37 and 38 is gradually reduced. As a result, the first to fourth pressure reduction control valves 21, 22, 41, and 42 are brought into a shut-off state. As a result, the differential pressure between the W / C pressure generated at each W / C 14, 15, 34, 35 and the high M / C pressure is reduced, and the W / C pressure of W / C 14, 15, 34, 35 is reduced. Increased pressure.

  As described above, the braking device 1 of the present embodiment is configured. When the ABS control is executed in such a braking device 1, the pump 19 is “at the time of pressure reduction control or holding control (when the first to fourth pressure increase control valves 17, 18, 37, 38 are shut off). 39, the brake fluid in the reservoirs 20 and 40 is discharged to the M / C 13 side and the brake fluid flows into the M / C 13 so that the brake pedal 11 is pushed back from the M / C 13 side. During control (when the brake fluid in the M / C 13 flows into the W / C), the brake fluid in the M / C 13 flows out to the W / C side, so that the brake pedal 11 enters the M / C 13 side. It is conceivable that “the pedal vibration is generated in accordance with the change in the control mode of the ABS control (pressure reduction control / holding control / pressure increase control)”.

  In particular, in the brake control device disclosed in Patent Document 1, since the pump discharge amount is controlled so that the brake fluid in the reservoir can be discharged to the M / C side within a fixed time, the vibration width of the pedal vibration is increased. That is, at the time of pressure reduction control, since the amount of brake fluid in the reservoir increases, the pump discharge amount increases, the amount of brake fluid flowing into the M / C increases, and the brake pedal is pushed back from the M / C side. The amount (hereinafter referred to as the brake pedal return amount) increases. Further, at the time of pressure increase control, it is conceivable that the amount of brake fluid in the reservoir decreases as a result of the discharge amount control of the pump. In this case, the pump discharge amount decreases, the amount of brake fluid flowing out of the M / C increases, and the operation amount (hereinafter referred to as the brake pedal entry amount) that the brake pedal enters the M / C side increases.

  In this embodiment, in order to suppress the pedal vibration, the motor rotation speed is controlled in consideration of the stroke change amount of the brake pedal 11, and the brake fluid discharge amount by the pumps 19 and 39 is controlled to control the M / C 13. Reduce the amount of brake fluid returned to the inside. Specifically, the following pump discharge amount control process is executed.

  FIG. 2 is a flowchart showing details of a pump discharge amount control process executed by the brake ECU 70. This process is executed every predetermined control cycle when the ABS control is started. For example, when it is determined that the ABS control start condition is satisfied in the well-known main flow of ABS control processing (not shown), that is, when the slip ratio exceeds a predetermined threshold, the ABS control is started. A flag to indicate is set. When this flag is set, the processing shown in FIG. 2 is executed.

  First, in step 100, a current st value that is a pedal stroke st at the current control cycle is detected. The pedal stroke st is calculated based on the detection signal of the stroke sensor 75.

  Next, in step 110, it is determined whether or not the motor operation timing is the second time or later. If ABS control is started and the control cycle is the first time, a negative determination is made in this step. However, if the control cycle is thereafter, the first pressure reduction control is already executed, and the motor 60 is driven. Affirmative determination is made. If a negative determination is made in this step, the routine proceeds to step 115, where the current st value, which is the pedal stroke st of the current control cycle, is stored as the reference pedal st value, that is, the initial setting of the reference value of the pedal stroke st. . Here, the reference value of the pedal stroke st is a stroke amount of the brake pedal 11 when there is no pedal vibration assumed in the road surface condition at that time, and is initially assumed in the road surface condition at the beginning of the ABS control. Set to stroke amount.

  Thereafter, the routine proceeds to step 120, where the duty ratio when the motor 60 is driven, that is, the ratio of the voltage application time to the motor 60 per unit time is determined. Here, since the motor is driven for the first time, the duty ratio is set to 100%. Thereafter, the process proceeds to step 125, where the motor 60 is driven at a duty ratio = 100%, whereby the motor 60 is fully rotated at the maximum number of rotations, and the process is terminated.

  On the other hand, if an affirmative determination is made at step 110 after the second motor operation timing, the routine proceeds to step 130. In step 130, the degree of deviation from the reference value of the pedal stroke st is derived, and it is determined whether or not the degree of deviation is large. In the present embodiment, the difference between the current st value and the reference pedal st value is derived, the absolute value of the integrated value (integral value) of this difference is derived as the divergence degree, and if the difference is equal to or greater than the absolute value of the difference, It is determined that the degree is large. If the degree of divergence is large and satisfies the relationship of Formula 1 and an affirmative determination is made in step 130, the routine proceeds to step 135 where the reference pedal st value is changed and the current st is the pedal stroke st at the current control cycle. Update to value.

数式１において、ｎ１は、前回乖離度合が大きいと判定されて基準ペダルｓｔ値が更新された時（以下、基準ペダルｓｔ値更新時という）を意味しており、ｎ２は、現在時を示している。すなわち、数式１は、基準ペダルｓｔ値更新時から現在時まで制御周期毎に繰り返し現在ｓｔ値と基準ペダルｓｔ値との差分を加算していき、その加算値の絶対値が第１閾値未満であれば乖離度合が小さく、第１閾値以上であれば乖離度合が大きいという関係を示している。このため、数式１を満たすか否かに基づいて、乖離度合が大きいか否かを判定できる。

In Equation 1, n1 means the time when the reference pedal st value is determined to be large and the reference pedal st value is updated (hereinafter referred to as the reference pedal st value update time), and n2 indicates the current time. Yes. That is, Formula 1 repeatedly adds the difference between the current st value and the reference pedal st value every control cycle from the time when the reference pedal st value is updated to the current time, and the absolute value of the added value is less than the first threshold value. If there is, the degree of deviation is small, and if it is greater than or equal to the first threshold, the degree of deviation is large. For this reason, based on whether Formula 1 is satisfied, it can be determined whether or not the degree of deviation is large.

  Thereafter, the routine proceeds to step 140, where it is determined whether or not the change amount of the pedal stroke st is large. Here, the difference between the pedal stroke st and the reference value is the difference between the current st value and the reference pedal st value, and when the absolute value of this difference is equal to or greater than the second threshold, it is determined that the amount of change in the pedal stroke st is large. ing.

  When a negative determination is made in step 140, the change amount of the pedal stroke st is within an allowable range, so the routine proceeds to step 145 and the duty ratio when the motor 60 is driven is maintained at the previous value. For example, if the change amount of the pedal stroke st from the initial motor drive remains acceptable, the duty ratio = 100% is maintained. Thereafter, the process proceeds to step 125, where the motor 60 is driven at the determined duty ratio, thereby rotating the motor 60 and terminating the process.

  When an affirmative determination is made in step 140, the amount of change in the pedal stroke st exceeds the allowable range. Therefore, the process proceeds to step 150 and subsequent steps, and a process for correcting the brake fluid discharge amount by the pumps 19 and 39 is executed. To do.

  First, in step 150, the target rotational speed of the motor 60 is corrected from the amount of change in the pedal stroke st.

  Here, in step 140, the difference between the current st value and the reference pedal st value is calculated as the change amount of the pedal stroke st. Further, in the present embodiment, it is assumed that the pedal stroke st is detected as a value in which the pedal stroke st becomes larger as the depression becomes larger when the pedal stroke st in a state before the brake pedal 11 is depressed is 0. Therefore, if the difference between the current st value and the reference pedal st value is a positive value, the brake pedal 11 is in the M / C 13 side. If the difference is a negative value, the brake pedal 11 is on the M / C 13 side. The state where it is pushed back from is shown.

  Therefore, if the difference between the current st value and the reference pedal st value is a positive value, it is better to increase the motor rotation speed in order to suppress the entry of the brake pedal 11 or to push back the brake pedal 11. It has become. Further, if the difference between the current st value and the reference pedal st value is a negative value, it is better to reduce the motor rotation speed in order to reduce the amount of pushing back of the brake pedal 11. Based on this, if the difference between the current st value and the reference pedal st value is a positive value, the target rotational speed correction amount is set to a positive value to increase the motor rotational speed. If the difference between the current st value and the reference pedal st value is a negative value, the target rotational speed correction amount is set as a negative value so as to reduce the motor rotational speed.

  Specifically, as shown in step 150, the target rotational speed correction amount is calculated using a map showing the relationship between the difference between the current st value and the reference pedal st value and the target rotational speed correction amount. ing. In this map, if the difference between the current st value and the reference pedal st value is within the second threshold used in the determination at step 140, that is, within the allowable range of the change amount of the pedal stroke st, the target rotational speed correction amount is set to 0. When the difference exceeds the second threshold value and is smaller than the second threshold value, the target rotational speed correction amount is set to a positive value and a negative value, respectively. When the difference between the current st value and the reference pedal st value exceeds the second threshold value, the target rotational speed correction amount becomes a larger value as the difference becomes larger. When the difference becomes smaller than the second threshold value, the target becomes smaller as the difference becomes smaller. The rotational speed correction amount is set to a small value.

  After obtaining the target rotational speed correction amount in this way, the process proceeds to step 155, where the target rotational speed of the motor 60 is determined. Specifically, the target rotational speed of the current control cycle is set by adding the target rotational speed correction amount set in step 150 to the previous value of the target rotational speed set in the previous control cycle. Thereafter, the routine proceeds to step 160, where the duty ratio is determined from the target rotational speed set at step 155. Since the relationship between the motor rotational speed and the duty ratio of voltage application to the motor 60 is determined, the duty ratio corresponding to the target rotational speed is set based on the relationship. Here, as shown in step 160, the relationship between the motor rotation speed and the duty ratio of voltage application to the motor 60 is almost proportional, so the map representing the relationship is used to correspond to the target rotation speed. The duty ratio to be determined is determined. Then, the process proceeds to step 125, and the motor 60 is driven at the duty ratio determined in step 160, whereby the motor 60 is rotated at the target rotational speed and the process is terminated.

  FIG. 3 is a timing chart of the W / C pressure, the motor rotational speed, and the pedal stroke st when the motor rotational speed is varied as in the present embodiment during ABS control. In FIG. 3, when the brake pedal 11 is depressed, a pedal stroke st is generated and the W / C pressure rises, ABS control is started at time T1, pressure reduction control is performed during a period from time T1 to T2, and time T2 This shows a case where the holding control is executed in the period of T3 and the pressure increasing control is executed in the period of time T3 to T4. In this timing chart, the motor 60 is continuously driven during the ABS control, including during the holding control, as an example.

  When the pressure reduction control is started at time T1 and the amount of brake fluid flowing into the M / C increases and the pedal stroke st decreases, the absolute value of the amount of change becomes equal to or greater than the second threshold value, and the motor rotation speed is increased. Reduced by correction. For this reason, the amount of brake fluid flowing into the M / C is reduced until the shift to pressure increase control thereafter, and the change in the pedal stroke st (return amount of the brake pedal 11) is reduced.

  Further, when the pressure increase control is started at the time T3 and the pedal stroke st is increased due to an increase in the amount of brake fluid flowing out from the inside of the M / C, the absolute value of the change amount becomes the second threshold value or more again, The motor speed is corrected and increased. For this reason, the amount of brake fluid flowing out from the M / C is reduced until the shift to the pressure reduction control thereafter, and the change in the pedal stroke st (the amount by which the brake pedal 11 is drawn) is reduced.

  In this way, the discharge amount of the pumps 19 and 39 is controlled by correcting the motor rotation speed, and the amount of brake fluid flowing into and out of the M / C is reduced, so that the change in the pedal stroke st is reduced. it can. Therefore, the width of pedal vibration can be reduced.

  FIG. 4 is a timing chart showing how the reference pedal st value is updated. This figure shows a case where the traveling road surface of the vehicle suddenly changes from an icing road with a small road surface friction coefficient μ to a large dry road and returns to the icing road again. The pedal stroke st shown in the figure actually changes as shown in FIG. 3, but is shown in a simplified manner. In addition, the reference value shown in the figure represents the right side of the above-described formula 1 (the absolute value of the integrated value of the difference between the current st value and the reference pedal st value).

  As shown in FIG. 4, first, the pedal stroke st when there is no pedal vibration assumed in the road surface condition of icing road at the start of ABS control is set to the reference st value. Then, the pedal stroke st changes during the pressure reduction control, the holding control, and the pressure increase control, and the reference value changes along with the change. However, in a situation where the road surface friction coefficient μ of the traveling road surface does not change suddenly, the reference stroke does not exceed the first threshold value because the pedal stroke st does not change so much that the reference pedal st value must be changed.

  When the icy road is suddenly changed to the dry road, the slip ratio is suddenly lowered, the amount of brake fluid supplied to the W / C 14, 15, 34, 35 side is suddenly increased, and the W / C pressure is suddenly increased. Increased, the deceleration is suddenly increased. For this reason, the amount of brake fluid returned into the M / C 13 decreases rapidly, the brake pedal 11 enters the M / C 13 side, and the pedal stroke st increases suddenly. At this time, since the reference value exceeds the first threshold value, the reference pedal st value is updated to be a pedal stroke st when there is no pedal vibration assumed in a road surface condition such as a dry road. Then, the reference pedal st value update time is newly set as n1, and the next reference value is calculated.

  After that, when the dry road returns to the icy road again, the same phenomenon as when the icy road suddenly changes to the dry road occurs, the reference pedal st value is updated again, and the pedal assumed in the road surface condition of the icy road again. This is the pedal stroke st when there is no vibration.

  In this way, the reference pedal st value is sequentially updated to the pedal stroke st when there is no pedal vibration assumed in the road surface condition at that time, and the reference pedal st value is suitably set according to the road surface condition at that time. This makes it possible to suppress an increase in the amplitude of pedal vibration due to a change in road surface condition during ABS control.

  As described above, in the braking device 1 according to the present embodiment, the brake ECU 70 executes the pump discharge amount control process, thereby controlling the discharge amounts by the pumps 19 and 39 during the ABS control. The amount of brake fluid flowing into and out of the engine can be reduced. As a result, it is possible to improve the brake feeling by reducing the width of the pedal vibration accompanying the change in the control mode (pressure reduction control / holding control / pressure increase control) of the ABS control.

(Other embodiments)
(1) In the above embodiment, the first and second differential pressure control valves 16 and 36 are provided as the brake hydraulic pressure circuit provided in the braking device, so that the pump 19 and the M / C pressure are not generated. As an example, a mode in which the side slip prevention control or the like can be performed by automatically applying the W / C pressure based on the operation of No. 39 is described. However, this is merely an example. For example, in FIG. 1, the first and second differential pressure control valves 16 and 36 and the pipes D and H are not provided, and the pressure regulating reservoirs 20 and 40 are merely reservoirs. The brake hydraulic pressure circuit configured as described above may be used. That is, as long as the braking device includes a brake hydraulic circuit including an ABS control unit capable of performing ABS control, the braking control device of the present invention is also applied to a braking device having a configuration as disclosed in Patent Document 1. can do.

  (2) In the above embodiment, the brake pedal 11 has been described as an example of the brake operation member. Therefore, the pedal stroke st is used as the operation amount of the brake operation member, but other operation amounts may be used. For example, other brake operation members may be used. In this case, other operation amounts may be used instead of the pedal stroke st. For example, when a brake lever is used as the brake operation member, an operation angle of the brake lever or the like can be used as the operation amount.

  In the above embodiment, the brake fluid discharge amount by the pumps 19 and 39 is controlled based on the difference between the pedal stroke st as the change amount of the pedal stroke st and the reference value. Specifically, as the difference increases toward the side where the brake pedal 11 enters the M / C 13 side, the amount of brake fluid discharged by the pumps 19 and 39 is increased, and the brake pedal 11 is pushed back from the M / C 13 side. The greater the difference is, the smaller the amount of brake fluid discharged by the pumps 19 and 39 is. Similarly, even when other operation amounts are used, the difference between the operation amount at the start of the ABS control and the reference value becomes larger on the side where the brake operation member enters the M / C 13 side, and the pumps 19 and 39 The brake fluid discharge amount may be increased, and the brake fluid discharge amount by the pumps 19 and 39 may be reduced as the brake operation member is pushed back from the M / C 13 side.

  (3) In the above-described embodiment, the brake fluid discharge amount by the pumps 19 and 39 is controlled using the operation amount of the brake operation member, but it can also be controlled based on the M / C pressure. That is, when the amount of brake fluid returned into the M / C 13 during ABS control increases, the M / C pressure increases and the brake operation member is pushed back from the M / C 13 side, and the brake returned into the M / C. When the amount of liquid decreases, the M / C pressure decreases and the brake operation member enters the M / C 13 side. For this reason, even if the discharge amount of the brake fluid by the pumps 19 and 39 is controlled based on the M / C pressure, the same effect as in the above embodiment can be obtained.

  Specifically, the M / C pressure at the start of the ABS control is set as a reference value for the M / C pressure, and the difference between the M / C pressure during the ABS control and the reference value is obtained. As the difference between the M / C pressure and the reference value increases toward the side where the brake operation member enters the M / C 13 side, the amount of brake fluid discharged by the pumps 19 and 39 increases so that the brake is applied from the M / C 13 side. The amount of brake fluid discharged from the pumps 19 and 39 may be reduced as the operating member is pushed back.

  The M / C pressure can be detected by an M / C pressure sensor. For example, an M / C pressure sensor is disposed between the M / C 13 and the first differential pressure control valve 16 in the pipe A. The detection signal of the M / C pressure sensor may be input to the brake ECU 70.

  (4) As described above, when the discharge amounts of the pumps 19 and 39 are controlled based on the operation amount and the M / C pressure, based on the difference between the operation amount or the M / C pressure and the corresponding reference value. Can be controlled. This is because the amount of brake fluid discharged by the pumps 19 and 39 increases as the difference increases toward the side where the brake operating member enters the M / C 13 side, and the brake operating member is pushed back from the M / C 13 side. It does not mean that the amount of brake fluid discharged by the pumps 19 and 39 decreases as the value increases. For example, when the difference exceeds a threshold that is assumed to have increased on the side where the brake operating member enters the M / C 13 side, the amount of brake fluid discharged by the pumps 19 and 39 is increased by a certain amount, and the M / C 13 The amount of brake fluid discharged by the pumps 19 and 39 may be reduced by a certain amount when a threshold that is assumed to have increased from the side to the side where the brake operation member is pushed back is exceeded.

  However, if the amount of brake fluid discharged by the pumps 19 and 39 is changed according to the difference, the amount of brake fluid discharged by the pumps 19 and 39 can be controlled more accurately.

  (5) In the above embodiment, the reference pedal st value is updated based on the integrated value (integrated value) of the difference between the current st value and the reference pedal st value. You may make it carry out based on the difference of quantity or M / C pressure, and the reference value corresponding to these.

  (6) The steps shown in each figure correspond to means for executing various processes. Specifically, the part of the brake ECU 70 that executes the process of step 100 is the acquisition means, the part that executes the process of step 115 is the setting means, the part that executes the process of step 130 is the derivation means, and the process of step 135 The part to be executed corresponds to the updating means, and the part to execute the processing of steps 140 to 160 corresponds to the control means.

  DESCRIPTION OF SYMBOLS 1 ... Brake device, 11 ... Brake pedal, 13 ... M / C, 14, 15, 34, 35 ... W / C, 17, 18, 37, 38 ... Pressure increase control valve, 19, 39 ... Pump, 20, 40 ... Pressure regulating reservoir, 21, 22, 41, 42 ... Pressure reducing control valve, 50 ... Brake hydraulic pressure control actuator, 60 ... Motor, 70 ... Brake ECU, 71-74 ... Wheel speed sensor, 75 ... Stroke sensor

Claims (3)

The brake fluid discharged from the wheel cylinder (14, 15, 34, 35) to the reservoir (20, 40) is sucked by the pump (19, 39), and discharged to the master cylinder (13) side, thereby the brake fluid. Is applied to a braking device including an anti-lock brake control unit (50) for refluxing
An acquisition means (100) for acquiring any one of an operation amount of the brake operation member (11) and a master cylinder pressure which is a brake fluid pressure in the master cylinder;
Control means (140 to 160) for controlling the amount of brake fluid discharged by the pump based on at least one of the operation amount acquired by the acquisition means and the master cylinder pressure. A braking control device. Setting for setting at least one of the operation amount and the master cylinder pressure at the start of the antilock brake control as a reference value for at least one of the operation amount and the master cylinder pressure in the antilock brake control Means (115),
The control means is based on a difference between the reference value set by the setting means and the operation amount acquired by the acquisition means and a value corresponding to the reference value of the master cylinder pressure. The brake control device according to claim 1, wherein the brake fluid discharge amount is controlled. Derivation means (130) for deriving a deviation degree between the reference value and the operation amount acquired by the acquisition means and a value corresponding to the reference value among the master cylinder pressure;
When the deviation degree derived by the deriving means is larger than a predetermined deviation degree, the reference value corresponds to the reference value among the operation amount and the master cylinder pressure acquired by the acquisition means. The braking control device according to claim 2, further comprising updating means (135) for updating with a value to be updated.

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