WO2012157050A1 - Dispositif de freinage de véhicule - Google Patents

Dispositif de freinage de véhicule Download PDF

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Publication number
WO2012157050A1
WO2012157050A1 PCT/JP2011/061107 JP2011061107W WO2012157050A1 WO 2012157050 A1 WO2012157050 A1 WO 2012157050A1 JP 2011061107 W JP2011061107 W JP 2011061107W WO 2012157050 A1 WO2012157050 A1 WO 2012157050A1
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WO
WIPO (PCT)
Prior art keywords
wheel
pressure
hydraulic
hydraulic circuit
control
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PCT/JP2011/061107
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English (en)
Japanese (ja)
Inventor
山田　芳久
洋司 溝口
聡 宇▲高▼
Original Assignee
トヨタ自動車株式会社
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Application filed by トヨタ自動車株式会社 filed Critical トヨタ自動車株式会社
Priority to PCT/JP2011/061107 priority Critical patent/WO2012157050A1/fr
Publication of WO2012157050A1 publication Critical patent/WO2012157050A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
    • B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
    • B60T13/14—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid using accumulators or reservoirs fed by pumps
    • B60T13/142—Systems with master cylinder
    • B60T13/145—Master cylinder integrated or hydraulically coupled with booster
    • B60T13/146—Part of the system directly actuated by booster pressure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T7/00—Brake-action initiating means
    • B60T7/12—Brake-action initiating means for automatic initiation; for initiation not subject to will of driver or passenger
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/26—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels

Definitions

  • the present invention relates to a braking device for a vehicle including a first system and a second system hydraulic circuit.
  • an object of the present invention is to provide a vehicle braking device that can appropriately increase the hydraulic pressure for each system during automatic braking when emergency deceleration is required.
  • a first system hydraulic circuit that supplies hydraulic pressure to a wheel cylinder of a first wheel of a vehicle; A second hydraulic circuit for supplying hydraulic pressure to the wheel cylinder of the second wheel of the vehicle; A first hydraulic pressure generating source that is provided in the hydraulic circuit of the first system and generates hydraulic pressure supplied to the wheel cylinder of the first wheel by the hydraulic circuit of the first system; A first valve provided in the hydraulic circuit of the first system and configured to vary a wheel cylinder pressure of the first wheel; A second hydraulic pressure generating source that is provided in the second hydraulic circuit and generates hydraulic pressure supplied to the wheel cylinder of the second wheel by the second hydraulic circuit; A second valve provided in the hydraulic circuit of the second system and configured to vary a wheel cylinder pressure of the second wheel; A third hydraulic pressure generating source that is connected to the hydraulic circuit of the first system and the hydraulic circuit of the second system, and generates hydraulic pressure according to the operation of the brake pedal of the driver; A control device that executes emergency braking control independent of the driver's operation of the brake pedal when
  • FIG. 1 is a schematic configuration diagram showing a main configuration of a vehicle braking device 1 according to an embodiment of the present invention and a main part of a vehicle 102 on which the vehicle braking device 1 is mounted. It is a figure which shows an example of the hydraulic circuit 200 by front and rear piping.
  • FIG. 3 is a diagram schematically showing the flow of oil when the pumps 260F and 260R in the hydraulic circuit 200 shown in FIG. 2 are operated. It is explanatory drawing of operation
  • movement of the M / C cut valve 206F. 3 is a flowchart illustrating an example of hydraulic control executed by the control device 10 in a hydraulic circuit 200 using front and rear piping.
  • FIG. 1 It is a figure which shows typically an example of the pressure increase suppression method with respect to a rear-wheel system, and is a figure which shows an example of the time series of the target control value set with respect to each of a front-wheel system and a rear-wheel system. It is a figure which shows the simultaneous series by the comparative example which applies the same (common) target control value with respect to a front-wheel system and a rear-wheel system. It is a characteristic view which shows an example of the relationship between a wheel cylinder pressure and oil consumption. It is a characteristic view showing an example of the relationship of the discharge oil amount with respect to the time of the pump 260F in the front wheel system hydraulic circuit 201F.
  • FIG. 5 is a flowchart showing another example of hydraulic control executed by the control device 10. It is a figure which shows an example of each map 1, 2, 3 used by the process shown in FIG. It is a figure which shows an example of the hydraulic circuit 200 'by X piping. 4 is a flowchart illustrating an example of hydraulic control executed by the control device 10 in a hydraulic circuit 200 ′ using X piping.
  • FIG. 1 is a schematic configuration diagram showing a main configuration of a vehicle braking device 1 according to an embodiment of the present invention and a main part of a vehicle 102 on which the vehicle braking device 1 is mounted.
  • 100FL and 100FR respectively indicate left and right front wheels of the vehicle 102
  • 100RL and 100RR respectively indicate left and right rear wheels that are driving wheels of the vehicle.
  • the left and right front wheels 100FL and 100FR may be steered via tie rods by a power steering device that is driven in response to steering of the steering wheel.
  • the vehicle braking device 1 includes a control device 10 and a hydraulic circuit 200.
  • the braking force of each wheel 100FR, 100FL, 100RR, 100RL is generated by the hydraulic pressure supplied to the wheel cylinders 224FR, 224FL, 224RR, 224RL by the hydraulic circuit 200, respectively.
  • the hydraulic circuit 200 is provided with a master cylinder 202.
  • the master cylinder 202 generates hydraulic pressure to be supplied to the wheel cylinders 224FR, 224FL, 224RR, 224RL in response to the depression operation of the brake pedal 190 by the driver.
  • the control device 10 may be configured by an ECU (electronic control unit) including a microcomputer.
  • the function of the control device 10 may be realized by any hardware, software, firmware, or a combination thereof.
  • any part or all of the functions of the control device 10 may be applied to an application-specific ASIC (application-specific). integrated circuit), FPGA (Field Programmable Gate) Array) or a DSP (digital signal processor).
  • the function of the control device 10 may be realized in cooperation with a plurality of ECUs.
  • the front radar sensor 134 is connected to the control device 10.
  • the front radar sensor 134 detects the state of a front obstacle (typically, the front vehicle) in front of the vehicle using radio waves (for example, millimeter waves), light waves (for example, lasers), or ultrasonic waves as detection waves.
  • the front radar sensor 134 detects information indicating a relationship between the front obstacle and the own vehicle, for example, a relative speed, a relative distance, and an azimuth (lateral position) of the front obstacle based on the own vehicle at a predetermined cycle.
  • the front radar sensor 134 is a millimeter wave radar sensor
  • the millimeter wave radar sensor may be, for example, an electronic scan type millimeter wave radar.
  • the front obstacle is detected using the Doppler frequency (frequency shift) of the radio wave.
  • the relative speed of the front obstacle is detected using the delay time of the reflected wave, and the direction of the front obstacle is detected based on the phase difference of the received wave among the plurality of receiving antennas.
  • the control device 10 is connected with wheel speed sensors 138FR, 138FL, 138RR, 138RL arranged on each wheel of the vehicle.
  • the wheel speed sensors 138FR, 138FL, 138RR, 138RL may be active sensors or passive sensors.
  • the control device 10 is connected to an acceleration sensor 136 that detects acceleration in the vehicle longitudinal direction generated in the vehicle.
  • the acceleration sensor 136 is attached, for example, under the center console of the vehicle.
  • the acceleration sensor 136 includes an acceleration sensor unit that outputs a signal corresponding to the acceleration in the vehicle longitudinal direction or the vehicle width direction that occurs in the mounted vehicle, and a yaw rate sensor unit that outputs a signal corresponding to the angular velocity generated around the center of gravity axis of the vehicle. May be realized by a semiconductor sensor.
  • the hydraulic circuit 200 is connected to the control device 10.
  • the control device 10 controls the braking force of each wheel 100FL, 100FR, 100RL, 100RR by controlling various valves (described later) provided in the hydraulic circuit 200.
  • the control method by the control device 10 will be described in detail later.
  • FIG. 2 is a diagram showing an example of a hydraulic circuit 200 using front and rear piping.
  • the hydraulic circuit 200 shown in FIG. 2 includes two systems of hydraulic circuits 201F and 201R.
  • the two hydraulic circuits 201F and 201R are composed of front and rear pipes that are divided into systems of front wheels 100FL and 100FR and rear wheels 100RL and 100RR.
  • the hydraulic circuit 201F is referred to as a front wheel system hydraulic circuit 201F
  • the hydraulic circuit 201R is referred to as a rear wheel system hydraulic circuit 201R.
  • a portion 220 surrounded by a two-dot chain line may be embodied as a brake actuator.
  • the master cylinder 202 has a first master cylinder chamber 202F and a second master cylinder chamber 202R defined by free pistons (not shown) urged to predetermined positions by compression coil springs on both sides thereof. is doing.
  • the front wheel system hydraulic circuit 201F will be described.
  • One end of a front wheel master passage 204F is connected to the first master cylinder chamber 202F.
  • the other end of the front wheel master passage 204F is connected to a master cylinder cut solenoid valve 206F (hereinafter referred to as an M / C cut valve 206F).
  • the M / C cut valve 206F is a normally open valve that is open when not controlled.
  • the M / C cut valve 206F has a function of regulating the hydraulic pressure generated by the pump 260F by controlling the open / closed state of the M / C cut valve 206F by the control device 10.
  • the opening degree of the M / C cut valve 206F can be controlled linearly, and a control hydraulic pressure corresponding to the opening degree is generated.
  • a flow path 205F is connected between the M / C cut valve 206F and the master cylinder 202 in the front wheel master passage 204F.
  • the channel 205F communicates with the reservoir 250F.
  • One end of a pump flow path 210F is connected to the reservoir 250F.
  • the other end of the pump channel 210F is connected to the high-pressure channel 208F.
  • a pump 260F and a check valve 262F are provided in the pump flow path 210F.
  • the discharge side of the pump 260F is connected to the high pressure flow path 208F via a check valve 262F.
  • the pump 260F is driven by, for example, a motor (not shown).
  • the pump 260F is controlled by the control device 10.
  • Pump 260F may be of any type including a piston type.
  • the pump 260F may include a camshaft that is eccentric with respect to the rotation shaft of the motor, and a piston in a cylinder that is disposed along the outer periphery of the camshaft.
  • the piston in the cylinder reciprocates when the camshaft rotates due to the rotation of the motor, sucks oil when moving to the center side, and pressurizes oil when moving to the outer periphery side. Is discharged.
  • the pump 260F pumps oil from the reservoir 250F and pumps the oil to the high-pressure channel 208F by the pump channel 210F via the check valve 262F (see FIG. 3).
  • the hydraulic circuit 200 does not include an accumulator that stores high-pressure oil discharged from the pump 260F.
  • the high pressure flow path 208F communicating with the wheel cylinders 224FL and 224FR is connected to the M / C cut valve 206F.
  • the high-pressure channel 208F branches into two and communicates with the wheel cylinders 224FL and 224FR.
  • holding solenoid valves 212FL and 212FR are respectively provided, and pressure reducing solenoid valves 214FL and 214FR are respectively provided.
  • Holding solenoid valves 212FL and 212FR are normally open valves that are open when not controlled.
  • the open / close state of the holding solenoid valves 212FL and 212FR is controlled by the control device 10.
  • the decompression solenoid valves 214FL and 214FR are normally closed valves that are closed when not controlled.
  • the controller 10 controls the open / close state of the decompression solenoid valves 214FL and 214FR.
  • the decompression solenoid valves 214FL and 214FR are connected to the reservoir 250F via the decompression passage
  • a rear wheel system hydraulic circuit 201R One end of a rear wheel master passage 204R is connected to the second master cylinder chamber 202R.
  • a master cylinder pressure sensor 265 is provided in the rear wheel master passage 204R.
  • the master cylinder pressure sensor 265 outputs a signal corresponding to the master cylinder pressure generated in the master passage 204R.
  • the output signal of the master cylinder pressure sensor 265 is supplied to the control device 10.
  • the other end of the rear wheel master passage 204R is connected to a master cylinder cut solenoid valve 206R (hereinafter referred to as an M / C cut valve 206R).
  • the M / C cut valve 206R is a normally open valve that is open when not controlled.
  • the M / C cut valve 206R has a function of regulating the hydraulic pressure generated by the pump 260R by controlling the open / close state of the M / C cut valve 206R by the control device 10.
  • the opening degree of the M / C cut valve 206R can be controlled linearly, and a control hydraulic pressure corresponding to the opening degree is generated.
  • a flow path 205R is connected between the M / C cut valve 206R and the master cylinder 202 in the rear wheel master passage 204R.
  • the flow path 205R communicates with the reservoir 250R.
  • One end of a pump flow path 210R is connected to the reservoir 250R.
  • the other end of the pump flow path 210R is connected to the high pressure flow path 208R.
  • a pump 260R and a check valve 262R are provided in the pump flow path 210R.
  • the discharge side of the pump 260R is connected to the high-pressure channel 208R via a check valve 262R.
  • the pump 260R is driven by, for example, a motor (not shown). This motor may be the same as the motor that drives the pump 260F for the front wheels.
  • the pump 260R is controlled by the control device 10. During operation, the pump 260R pumps oil from the reservoir 250R and pumps the oil to the high-pressure channel 208R through the pump channel 210R via the check valve 262R (see FIG. 3).
  • the hydraulic circuit 200 does not include an accumulator that stores high-pressure oil discharged from the pump 260R.
  • the M / C cut valve 206R is connected to a high pressure flow path 208R communicating with the wheel cylinders 224RL and 224RR.
  • the high-pressure channel 208R branches into two and communicates with the wheel cylinders 224RL and 224RR.
  • holding solenoid valves 212RL and 212RR are provided, and pressure reducing solenoid valves 214RL and 214RR are provided.
  • Holding solenoid valves 212RL and 212RR are normally open valves that are open when not controlled.
  • the open / close state of the holding solenoid valves 212RL and 212RR is controlled by the control device 10.
  • the decompression solenoid valves 214RL and 214RR are normally closed valves that are closed when not controlled.
  • the open / close state of the decompression solenoid valves 214RL and 214RR is controlled by the control device 10.
  • the decompression solenoid valves 214RL and 214RR are connected to the reservoir 250R via the decompression
  • each valve (M / C cut valves 206F, 206R, holding solenoid valves 212FL, 212FR, 212RL, 212RR, and pressure reducing solenoid valves 214FL, 214FR, 214RL, 214RR) is in the non-control position.
  • the pumps 260F and 260R are in a non-operating state.
  • the pressure in the first master cylinder chamber 202F is supplied to the wheel cylinders 224FL and 224FR
  • the pressure in the second master cylinder chamber 202R is supplied to the wheel cylinders 224RL and 224RR. Therefore, during normal braking, the pressure in the wheel cylinder of each wheel, that is, the braking force, is increased or decreased according to the operation amount (depression force) of the brake pedal 190.
  • FIG. 3 is a diagram schematically showing the oil flow when the pumps 260F and 260R in the hydraulic circuit 200 shown in FIG. 2 are operated.
  • the flow of oil when the pump 260F is operated in the front wheel system hydraulic circuit 201F will be described.
  • the operation of the pump 260R is substantially the same as the operation of the pump 260F.
  • the oil in the reservoir 250F flowing in from the master cylinder 202 via the flow path 205F is pumped to the high pressure flow path 208F by the pump flow path 210F via the check valve 262F.
  • the holding solenoid valves 212FL and 212FR are in the open position, this oil is supplied to the wheel cylinders 224FL and 224FR from the high pressure passage 208F, and the pressure in the wheel cylinders 224FL and 224FR (wheel cylinder pressure) is increased.
  • the pressure reducing solenoid valves 214FL and 214FR are in the closed position, and the wheel cylinder pressure is increased.
  • the oil pumped to the high pressure channel 208F flows to the master passage 204F via the M / C cut valve 206F.
  • the flow rate of this oil changes according to the open / closed state (opening degree) of the M / C cut valve 206F (see FIG. 4).
  • the pressures pumped up by the pump 260F are supplied to the wheel cylinders 224FL and 224FR, and the pressures pumped up by the pump 260R are supplied to the wheel cylinders 224RL and 224RR.
  • the braking pressure of each wheel is independent of the amount of operation of the brake pedal 190 (the M / C cut valves 206F and 206R, the holding solenoid valves 212FL, 212FR, 212RL, 212RR, and the pressure reducing solenoid).
  • the valve 214FL, 214FR, 214RL, 214RR can be controlled according to the operating state.
  • FIG. 4A and 4B are explanatory diagrams of the operation of the M / C cut valve 206F.
  • FIG. 4A shows a state in which the opening degree of the M / C cut valve 206F is relatively small
  • FIG. 4B shows the M / C cut valve 206F.
  • the state where the opening degree of 206F is smaller is shown.
  • the operation of the M / C cut valve 206R may be the same.
  • the M / C cut valve 206F has a valve element 274 disposed in the valve chamber 270 so as to be able to reciprocate.
  • the valve chamber 270 is connected to a front wheel master passage 204F from the master cylinder 202 and a high pressure passage 208F communicating with the wheel cylinders 224FR and 224FL via an internal passage 278 and a port 280.
  • a solenoid 282 is disposed around the valve element 274, and the valve element 274 is urged to a valve opening position by a compression coil spring 284. When a drive voltage is applied to the solenoid 282, the valve element 274 is biased against the port 280 against the spring force of the compression coil spring 284.
  • the control device 10 controls the magnitude of the applied current (differential pressure instruction value) to the solenoid 282 of the M / C cut valve 206F, so that the hydraulic pressure in the high-pressure flow path 208F (in the master passage 204F) is controlled.
  • the differential pressure between the hydraulic pressure and the hydraulic pressure in the high-pressure channel 208F can be controlled.
  • the M / C cut valve 206F incorporates a check valve 286 that allows only the flow of oil from the valve chamber 270 toward the high-pressure channel 208F.
  • FIG. 5 is a flowchart showing an example of hydraulic control executed by the control device 10.
  • the processing routine shown in FIG. 5 may be repeatedly executed at predetermined intervals while the vehicle is traveling.
  • the control device 10 determines a sudden braking command start condition.
  • the sudden braking command start condition may be satisfied when a predetermined emergency deceleration is requested.
  • TTC Time to Collation
  • the control device 10 calculates a TTC for a front obstacle in a predetermined direction (lateral position) based on the detection result from the front radar sensor 134, and the calculated TTC calculates a predetermined value (for example, 1 second). If so, go to Step 502.
  • the TTC may be derived by dividing the relative distance to the front obstacle by the relative speed with respect to the front obstacle.
  • the automatic driving control for example, it may be satisfied when the magnitude of the deceleration required to maintain a predetermined lower distance between the vehicle ahead and the vehicle ahead exceeds a predetermined value.
  • the sudden braking command start condition may not be satisfied in the automatic driving control but may be satisfied only in the collision avoidance control. If the sudden braking command start condition is satisfied, the process proceeds to step 502. Otherwise, the process ends.
  • the control device 10 executes a four-wheel automatic brake in which the pressure increase by the rear wheel system hydraulic circuit 201R is suppressed based on the target control value.
  • the control device 10 operates the pumps 260F and 260R and controls the M / C cut valves 206F and 206R to increase the wheel cylinder pressures of the wheel cylinders 224FL, 224FR, 224RL and 224RR.
  • the control device 10 controls the M / C cut valves 206F and 206R so that the wheel cylinder pressures of the rear wheel cylinders 224RL and 224RR do not exceed the wheel cylinder pressures of the front wheel cylinders 224FL and 224FR. To control.
  • the pressure increase suppression for the rear wheel system can be realized in a wide variety of modes, and may be realized in any mode.
  • the pressure increase start timing by the rear wheel system hydraulic circuit 201R may be delayed by a predetermined delay time ⁇ T with respect to the pressure increase start timing by the front wheel system hydraulic circuit 201F.
  • ⁇ T a predetermined delay time
  • Other specific examples of the method for suppressing pressure increase with respect to the rear wheel system will be described later.
  • the target control value may be set for any physical quantity related to the wheel cylinder pressure of the wheel.
  • the target control value may be a target deceleration, a hydraulic target value for the wheel cylinder pressure, a target value of a pressure increase gradient for the wheel cylinder pressure, or M / It may be a target value of a differential pressure instruction value (applied current value) for the C cut valves 206F and 206R.
  • the target control value may be a fixed value or a variable value set according to a relative relationship (such as TTC) with the front obstacle. In the case of a fixed value, the target control value may be, for example, a target deceleration of 6.0 m / s 2 or a hydraulic target value for each wheel cylinder pressure of 5 Mpa.
  • step 504 the control device 10 determines a sudden braking command end condition.
  • the sudden braking command end condition is, for example, when a collision is detected based on the acceleration sensor 136 or the like, when the vehicle body speed becomes 0 km / h, or when the TTC exceeds 1.5 [seconds], May be satisfied when it continues for a predetermined time (for example, 3 seconds) or longer. If the sudden braking command termination condition is satisfied, the routine ends. Otherwise, the process returns to step 502.
  • the four-wheel automatic braking in step 502 is typically executed in a situation where the driver does not operate the brake pedal 190. That is, the target control value used in step 502 is a value (including a fixed value) determined based on factors other than the operation amount of the brake pedal 190. If the driver operates the brake pedal 190 (for example, detected based on the pedaling force switch 192) after starting the four-wheel automatic braking, the operation of the brake pedal 190 is ignored and the four-wheel automatic braking is performed. May be continued. Alternatively, when the driver operates the brake pedal 190 after starting the four-wheel automatic braking, for example, when the master cylinder pressure becomes equal to or higher than a predetermined pressure, the normal braking may be performed.
  • the wheel cylinders 224FL, 224FR are added by adding both hydraulic pressures (or selecting the larger one). It is good also as applying to 224RL and 224RR.
  • the four-wheel automatic braking in step 502 may be executed under a situation where the driver is operating the brake pedal 190.
  • the sudden braking command start condition may be varied depending on whether the driver operates the brake pedal 190 or not.
  • the TTC as a threshold value that satisfies the sudden braking command start condition may be changed to a long time (for example, 1.5 seconds).
  • the target control value used in step 502 may be determined based on factors other than the operation amount of the brake pedal 190.
  • the holding solenoid valves 212FL, 212FR, 212RL, 212RR and the pressure reducing solenoid valves 214FL, 214FR, 214RL, 214RR are all maintained in the normal state. That is, the holding solenoid valves 212FL, 212FR, 212RL, 212RR and the pressure reducing solenoid valves 214FL, 214FR, 214RL, 214RR are VSC (Vehicle In the vehicle stabilization control such as Stability Control), each wheel is individually controlled.
  • VSC Vehicle In the vehicle stabilization control such as Stability Control
  • the four-wheel automatic brake in step 502 is control for each system, and different control is not executed in the same system.
  • the ABS (anti-lock) vehicle stabilization control such as a brake system) or VSC may be activated.
  • the four-wheel automatic brake may be stopped, or such other control may be executed while continuing the four-wheel automatic brake.
  • the holding solenoid valves 212FL, 212FR, 212RL, 212RR and the pressure reducing solenoid valves 214FL, 214FR, 214RL, 214RR are controlled while performing the same control as the M / C cut valves 206F, 206R during the four-wheel automatic braking. It is good also as performing control according to the control law of ABS or vehicle stabilization control.
  • FIG. 6 is a diagram showing an example of a time series (target control value pattern) of target control values set for each of the front wheel system and the rear wheel system.
  • the target control value is a hydraulic target value for the wheel cylinder pressure.
  • the rise timing of the rear hydraulic target value is delayed by a predetermined delay time ⁇ T from the rise timing of the front hydraulic target value.
  • the front hydraulic pressure target value increases toward the final front hydraulic pressure target value (5 Mpa in this example) at the start of the sudden braking command.
  • the rear hydraulic pressure target value increases toward the final rear hydraulic pressure target value (5 Mpa in this example) after a predetermined delay time ⁇ T from the start of the sudden braking command.
  • the final target value (the final front hydraulic pressure target value and the final rear hydraulic pressure target value) may correspond to a target control value that should be finally realized by the four-wheel automatic brake.
  • FIG. 7 is a diagram showing a simultaneous sequence according to a comparative example in which the same (common) target control value is applied to the front wheel system and the rear wheel system.
  • both the front hydraulic pressure target value and the rear hydraulic pressure target value increase toward the final hydraulic pressure target value (5 Mpa in this example) at the start of the sudden braking command.
  • the rear wheel system hydraulic circuit 201R due to the characteristic difference between the rear wheel system hydraulic circuit 201R and the front wheel system hydraulic circuit 201F, as shown by the solid lines attached to the front actual hydraulic pressure and the rear actual hydraulic pressure in FIG.
  • the wheel cylinder pressures of the wheel cylinders 224RL and 224RR exceed the wheel cylinder pressures of the front wheel cylinders 224FL and 224FR.
  • the front wheel system hydraulic circuit 201F has a significantly larger capacity of the front caliper than the rear caliper, so that the consumed oil required to generate the same oil pressure as the rear wheel system hydraulic circuit 201R.
  • the amount increases (see FIG. 8). Therefore, in this comparative example, during four-wheel automatic braking, the wheel cylinder pressures of the rear wheel cylinders 224RL and 224RR increase before the wheel cylinder pressures of the front wheel cylinders 224FL and 224FR, and the rear wheel lock tendency become.
  • the rising timing of the rear hydraulic target value is delayed by a predetermined delay time ⁇ T from the rising timing of the front hydraulic target value, so as shown in FIG. It is possible to prevent the wheel cylinder pressures of 224RL and 224RR from exceeding the wheel cylinder pressures of the front wheel cylinders 224FL and 224FR. As a result, the tendency to lock the rear wheel during four-wheel automatic braking when emergency deceleration is required can be prevented, and vehicle stability can be improved.
  • the predetermined delay time ⁇ T is preferably a difference in characteristics between the rear wheel system hydraulic circuit 201R and the front wheel system hydraulic circuit 201F, in particular, the oil consumption necessary for generating the same wheel cylinder pressure. It is set in consideration of the amount difference.
  • the predetermined delay time ⁇ T may be a fixed value such as 200 msec.
  • the front hydraulic pressure target value and the rear hydraulic pressure target value rise steeply and rise toward the final front hydraulic pressure target value and the final rear hydraulic pressure target value, respectively. It may be increased in steps.
  • FIG. 8 is a characteristic diagram showing an example of the relationship between wheel cylinder pressure and oil consumption.
  • FIG. 8 shows the same relationship in the front wheel system hydraulic circuit 201F and the same relationship in the rear wheel system hydraulic circuit 201R.
  • the amount of oil consumed to generate the same wheel cylinder pressure differs between the front wheel system hydraulic circuit 201F and the rear wheel system hydraulic circuit 201R. This is mainly based on the structural difference (for example, the difference between the capacity of the front caliper and the capacity of the rear caliper).
  • Such a characteristic diagram may be obtained based on a test or calculation, or a design value may be used.
  • FIG. 9 is a characteristic diagram showing an example of the discharge capacity (discharge oil amount with respect to time) of the pump 260F in the front wheel system hydraulic circuit 201F. Similarly, such a characteristic diagram may be obtained based on a test or calculation, or a design value may be used.
  • the final hydraulic target value for the wheel cylinder pressure is Pt.
  • consumption of the wheel system hydraulic circuit 201R after required for implementing the final and oil consumption Q F in the front line hydraulic circuit 201F necessary for realizing the hydraulic target value Pt of the final hydraulic target value Pt and an oil amount Q R, as shown in FIG. 8 is obtained from the characteristic diagram.
  • These oil consumption difference Q diff is Q F ⁇ Q R.
  • the operation time T t of the pump 260F required until oil consumption Q F is obtained, as shown in FIG. 9 is obtained from the characteristic diagram.
  • the predetermined delay time ⁇ T may be calculated by the following equation.
  • the control device 10 determines the predetermined delay time based on the final hydraulic target value Pt and the characteristic diagrams shown in FIGS. 8 and 9 in the process of step 502 shown in FIG. ⁇ T may be calculated.
  • the relationship between the final hydraulic pressure target value Pt and the predetermined delay time ⁇ T may be created in advance as a map and stored in the memory.
  • a predetermined delay time ⁇ T may be calculated for each of a plurality of final hydraulic target values Pt (for example, 1 Mpa, 3 Mpa, 5 Mpa, and 7 Mpa) using Equation (1) to create a map.
  • the control device 10 may read the predetermined delay time ⁇ T corresponding to the final hydraulic pressure target value Pt.
  • the final hydraulic pressure target value not specified in the map is obtained by interpolating a predetermined delay time ⁇ T corresponding to the two final hydraulic pressure target values close thereto.
  • a predetermined delay time ⁇ T corresponding to the above may be calculated.
  • the predetermined delay time ⁇ T may be calculated by the following equation.
  • ⁇ T T t ⁇ T tR equation (2)
  • Q R is the operating time of the pump 260R required until obtained.
  • T tR is a characteristic diagram as shown in FIG. 9 and may be similarly calculated based on a characteristic diagram of the discharge oil amount with respect to time of the pump 260R in the rear wheel system hydraulic circuit 201R.
  • a predetermined delay time ⁇ T may be calculated for each of a plurality of final hydraulic target values Pt (for example, 1 Mpa, 3 Mpa, 5 Mpa, and 7 Mpa) according to the equation (2), and a map may be created. .
  • FIG. 10 is a diagram showing another example of a time series (target control value pattern) of target control values set for each of the front wheel system and the rear wheel system.
  • the target control value is a hydraulic target value for the wheel cylinder pressure.
  • the time series of the values are indicated by dotted lines, and the actual wheel cylinder pressures (front actual hydraulic pressure) of the front wheel cylinders 224FL and 224FR when controlled by these hydraulic target value patterns are shown.
  • the time series and the time series of the actual wheel cylinder pressures (rear actual hydraulic pressure) of the wheel cylinders 224RL and 224RR of the rear wheels are indicated by solid lines.
  • the rise timing of the rear hydraulic target value is the same as the rise timing of the front hydraulic target value, but the increase gradient of the rear hydraulic target value is set lower than the increase gradient of the front hydraulic target value.
  • the front hydraulic pressure target value increases at a relatively steep slope toward the final front hydraulic pressure target value (5 Mpa in this example) at the start of the sudden braking command.
  • the rear hydraulic pressure target value increases with a relatively gentle gradient toward the final front hydraulic pressure target value (5 Mpa in this example) at the start of the sudden braking command.
  • an upper limit value lower than the increase gradient of the front hydraulic pressure target value may be set for the increase gradient of the rear hydraulic pressure target value.
  • the upper limit value (or the difference between the increase gradient of the rear hydraulic pressure target value and the increase gradient of the front hydraulic pressure target value) with respect to the increase gradient of the rear hydraulic pressure target value is determined by the wheel cylinder pressure of the rear wheel cylinders 224RL and 224RR.
  • the wheel cylinder pressure is set so as not to exceed the wheel cylinder pressure of the wheel cylinders 224FL and 224FR.
  • the rear actual hydraulic pressure target value and the rear hydraulic pressure target value increase at the same gradient with respect to time, as indicated by the solid lines attached to the front actual hydraulic pressure and the rear actual hydraulic pressure in FIGS. Due to the difference in oil consumption between the front wheel system hydraulic circuit 201F and the rear wheel system hydraulic circuit 201R as shown in FIG. 8, the rear actual hydraulic pressure increases with a steeper slope than the front actual hydraulic pressure. .
  • the increase gradient of the rear hydraulic target value is smaller than the increase gradient of the front hydraulic target value, and thus the difference between the increase gradient of the rear actual hydraulic pressure and the increase gradient of the front actual hydraulic pressure. Can be reduced.
  • the method shown in FIG. 10 can be combined with the method shown in FIG. That is, it is possible to delay the rise timing of the rear hydraulic pressure target value from the rise timing of the front hydraulic pressure target value and set the increase gradient of the rear hydraulic pressure target value lower than the increase gradient of the front hydraulic pressure target value.
  • the front hydraulic pressure target value rises steeply and rises toward the final front hydraulic pressure target value, but it may increase in two or more steps.
  • the rear hydraulic pressure target value rises gently and rises toward the final rear hydraulic pressure target value, but may increase in two or more steps.
  • FIG. 11 is a flowchart showing another example of hydraulic control executed by the control device 10.
  • the processing routine shown in FIG. 11 may be repeatedly executed at predetermined intervals while the vehicle is traveling.
  • FIG. 12 is a diagram showing an example of each map 1, 2, 3 used in the processing shown in FIG.
  • the control device 10 determines a sudden braking command start condition.
  • the sudden braking command start condition may be satisfied when a predetermined emergency deceleration is requested.
  • the sudden braking command start condition is satisfied when there is a request from a pre-crash system that performs collision avoidance control with a forward obstacle.
  • a predetermined value for example, 1 second.
  • the control device 10 may constitute a pre-crash system control device.
  • the sudden braking command start condition is also satisfied when there is a request from a system other than the pre-crash system (a system that performs preceding vehicle tracking control, auto cruise control, or similar automatic driving control). .
  • control device 10 may constitute a control device for a system that performs automatic driving control such as preceding vehicle following control and auto cruise control. If the sudden braking command start condition is satisfied, the process proceeds to step 1102; otherwise, the process ends.
  • step 1102 the control device 10 determines whether or not the request is an emergency deceleration request from the pre-crash system. If it is a request for emergency deceleration from the pre-crash system, the process proceeds to step 1104. If it is a request for emergency deceleration from other systems, the process proceeds to step 1108.
  • step 1104 the control device 10 executes a four-wheel automatic brake in which pressure increase by the rear wheel system hydraulic circuit 201R is suppressed based on the map 1 (see FIG. 12).
  • the control device 10 operates the pumps 260F and 260R, and calculates the pressure increase gradient instruction amount in common for the front wheel system hydraulic circuit 201F and the rear wheel system hydraulic circuit 201R. That is, a common pressure increase gradient command amount is calculated for the M / C cut valve 206F of the front wheel system hydraulic circuit 201F and the M / C cut valve 206R of the rear wheel system hydraulic circuit 201R.
  • the pressure increase gradient instruction amount may be calculated in a manner that gradually increases with time toward the final pressure increase gradient instruction amount.
  • the final pressure increase gradient instruction amount may be a fixed value or a variable value set according to a relative relationship (such as TTC) with the front obstacle.
  • the control device 10 calculates a differential pressure command value corresponding to the calculated pressure increase gradient command amount based on the map 1, and calculates the differential pressure command value (current) as the M / C cut valves 206F and 206R, respectively. Apply to.
  • the differential pressure command value with respect to the pressure increase gradient command amount is respectively determined for the M / C cut valve 206F of the front wheel system hydraulic circuit 201F and the M / C cut valve 206R of the rear wheel system hydraulic circuit 201R. Different.
  • the differential pressure command value becomes the predetermined gradient G1 and the predetermined value S1 ( (The value close to the upper limit value or a value close to the upper limit value), while the M / C cut valve 206R of the rear wheel system hydraulic circuit 201R has a pressure increase gradient instruction amount of the second predetermined value ⁇ P A2.
  • the differential pressure indication value does not increase until it exceeds (> ⁇ P A1 ).
  • the same effect as the case where the predetermined delay time ⁇ T as described with reference to FIG. 6 is set can be obtained.
  • the difference between the first predetermined value ⁇ P A1 and the second predetermined value ⁇ P A2 may be set in the same way as when the predetermined delay time ⁇ T is set.
  • step 1106 the control device 10 determines the sudden braking command end condition. For example, when the collision is detected, the vehicle speed becomes 0 km / h, or when the TTC exceeds 1.5 [seconds], the sudden braking command is terminated for a predetermined time (for example, 3 seconds). ) It may be satisfied if it continues for the above. If the sudden braking command end condition is satisfied, the process ends as it is. Otherwise, the process returns to step 1104.
  • step 1108 the control unit 10 calculates in common to the rear wheel system hydraulic circuit 201R and the front wheel system hydraulic circuit 201F the pressure increase gradient indicated amounts, or pressure-increase gradient instruction amount is larger than the predetermined value [Delta] P A not Determine whether. If the pressure increase gradient instruction amount is larger than the predetermined value [Delta] P A, the process proceeds to step 1110, if the pressure increase gradient instructed amount is smaller than the predetermined value [Delta] P A, the process proceeds to step 1114.
  • the determination increasing gradient indicated amounts of whether greater than a predetermined value [Delta] P A may be performed only for the pressure increase gradient instruction amount calculated for the first time. In this case, after the next cycle, the process may proceed to step 1110 or 1114 according to the determination result for the pressure increase gradient instruction amount calculated for the first time.
  • step 1110 the control device 10 executes a four-wheel automatic brake in which pressure increase by the rear wheel system hydraulic circuit 201R is suppressed based on the map 2 (see FIG. 12). Specifically, the control device 10 operates the pumps 260F and 260R. Then, the control device 10 calculates a differential pressure command value corresponding to the calculated pressure increase gradient command amount based on the map 2, and uses the differential pressure command value (current) as the M / C cut valves 206F and 206R, respectively. Apply to.
  • the differential pressure command value with respect to the pressure increase gradient command amount is respectively determined for the M / C cut valve 206F of the front wheel system hydraulic circuit 201F and the M / C cut valve 206R of the rear wheel system hydraulic circuit 201R. Different.
  • the pressure-increase gradient instruction amount exceeds a predetermined value [Delta] P A, differential pressure instruction value toward a predetermined value S1 at a predetermined gradient G1 whereas increasing Te, for M / C cut valve 206R for the rear wheels system hydraulic circuit 201R, the pressure-increase gradient instruction amount exceeds a predetermined value [Delta] P a, differential pressure instruction value is a predetermined gradient G2 ( ⁇ G1) increases toward a predetermined value S2 ( ⁇ S1).
  • the differential pressure command value for the M / C cut valve 206R of the rear wheel system hydraulic circuit 201R is compared with the differential pressure command value for the M / C cut valve 206F of the front wheel system hydraulic circuit 201F.
  • it increases toward a small predetermined value S2 with a gentle slope.
  • the pressure increase gradient command amount (target decrease) is lower than when emergency deceleration is requested from the pre-crash system. (Speed) tends to be small. That is, at the time of emergency deceleration by a system that performs automatic driving control such as preceding vehicle tracking control or auto cruise control, the wheel cylinder pressures of the rear wheel cylinders 224RL and 224RR are set in contrast to emergency deceleration by the pre-crash system. The need for increasing pressure to near the upper limit can be reduced.
  • the predetermined value S2 of the differential pressure instruction value for the M / C cut valve 206R is smaller than the predetermined value S1 of the differential pressure instruction value for the M / C cut valve 206F.
  • the vehicle wheel stability can be improved by preventing the wheel cylinder pressure on the side from being increased to the same level as the wheel cylinder pressure on the front wheel side.
  • step 1112 the control device 10 determines a sudden braking command end condition.
  • the sudden braking command end condition may be satisfied, for example, when a necessary inter-vehicle distance from the preceding vehicle is maintained, or when the sudden braking command continues for a predetermined time (for example, 3 seconds) or longer. If the sudden braking command end condition is satisfied, the process ends as it is. Otherwise, the process returns to step 1108.
  • the control device 10 executes the four-wheel automatic braking that does not suppress the pressure increase by the rear wheel system hydraulic circuit 201R based on the map 3 (see FIG. 12). Specifically, the control device 10 operates the pumps 260F and 260R. The control device 10 calculates a differential pressure command value corresponding to the calculated pressure increase gradient command amount based on the map 2, and applies the differential pressure command value (current) to the M / C cut valves 206F and 206R. To do.
  • Map 3 the differential pressure command value for the pressure increase gradient command amount is the same for the M / C cut valve 206F of the front wheel system hydraulic circuit 201F and the M / C cut valve 206R of the rear wheel system hydraulic circuit 201R. .
  • the differential pressure instruction value increases toward a predetermined value S3 ( ⁇ S2) with a gentle predetermined gradient G3 ( ⁇ G2).
  • step 1116 the control device 10 determines the sudden braking command end condition.
  • the sudden braking command end condition may be satisfied, for example, when the necessary inter-vehicle distance from the preceding vehicle is maintained, or when the sudden braking command continues for a predetermined time (for example, 2 seconds). If the sudden braking command end condition is satisfied, the process ends as it is. Otherwise, the process returns to step 1108.
  • FIG. 13 is a diagram illustrating an example of a hydraulic circuit 200 ′ using X piping.
  • the hydraulic circuit 200 'shown in FIG. 13 includes two systems of hydraulic circuits 201A and 201B.
  • the two systems of hydraulic circuits 201A and 201B are composed of X pipes that are divided into systems of a right front wheel 100FR and a left rear wheel 100RL, and a left front wheel 100FL and a right rear wheel 100RR.
  • the hydraulic circuit 201A related to the right front wheel 100FR and the left rear wheel 100RL is referred to as a first system hydraulic circuit 201A
  • the hydraulic circuit 201B related to the left front wheel 100FL and the right rear wheel 100RR is referred to as a second system hydraulic circuit 201B.
  • a portion 220 surrounded by a two-dot chain line may be embodied as a brake actuator.
  • the hydraulic circuit 200 ′ with X piping has a front wheel cylinders 224 FL and 224 FR and rear wheel cylinders 224 RL and 224 RR arranged with respect to the hydraulic circuit 200 with front and rear piping shown in FIG. Except for differences, they may be substantially the same. Therefore, in FIG. 13, the components that may be the same as those of the hydraulic circuit 200 with the front and rear pipes shown in FIG. “R” is changed to “A” and “B”, respectively, and the description is omitted.
  • FIG. 14 is a flowchart illustrating an example of hydraulic control executed by the control device 10.
  • the processing routine shown in FIG. 14 may be repeatedly executed at predetermined intervals while the vehicle is traveling.
  • Steps 1400 and 1404 may be the same as steps 500 and 504 in the flowchart described with reference to FIG.
  • step 1402 the control unit 10 based on the target control value, the four-wheel automatic braking in a manner to keep the pressure difference between the systems in the first system hydraulic circuit 201A and the second system hydraulic circuit 201B within a predetermined value D Th Execute.
  • the control device 10 operates the pumps 260A and 260B and controls the M / C cut valves 206A and 206B to increase the wheel cylinder pressures of the wheel cylinders 224FL, 224FR, 224RL and 224RR.
  • the control device 10 determines the pressure difference between the wheel cylinder pressures of the wheel cylinders 224FL and 224RR related to the first system hydraulic circuit 201A and the wheel cylinder pressures of the wheel cylinders 224FL and 224RR related to the second system hydraulic circuit 201B. in a fit such embodiments within a predetermined value D Th, controls the M / C cut valve 206A, 206B.
  • the target control value may be set for any physical quantity related to the wheel cylinder pressure of the wheel.
  • the target control value may be a target deceleration, a hydraulic pressure target value for the wheel cylinder pressure, a pressure increase gradient target value for the wheel cylinder pressure, or M / C. It may be a differential pressure target value (applied current value) for the cut valves 206A and 206B.
  • the target control value may be a fixed value or a variable value set according to a relative relationship (such as TTC) with the front obstacle.
  • the method for reducing the pressure difference between the systems in Step 1402 can be realized in a wide variety of modes, and may be realized in any mode. For example, based on the difference in the amount of oil consumed between the systems in the first system hydraulic circuit 201A and the second system hydraulic circuit 201B (difference caused by the difference in piping length, etc.), the system with the larger amount of oil consumption On the other hand, the target control value may be raised. For example, the consumed oil amount necessary to achieve the oil consumption Q A required to achieve the final target control value in the first system hydraulic circuit 201A, the final target control value in the second system hydraulic circuit 201B Q B is obtained based on the characteristic diagram as shown in FIG.
  • N Q diff / Q min
  • Q min is the smaller of the consumed oil amount Q A and the consumed oil amount Q B.
  • the relationship between the index value N and the target control value raising amount ⁇ P may be created in advance as a map.
  • the target control value is a hydraulic pressure target value for the wheel cylinder pressure and the final target control value is a fixed value (for example, 5 Mpa)
  • the target control value raising amount ⁇ P is also a fixed value (for example, , 0.2 Mpa) may be determined in advance.
  • the constant value DTh is set so that the pressure difference between the systems in the first system hydraulic circuit 201A and the second system hydraulic circuit 201B does not affect the vehicle behavior.
  • the constant value DTh may be determined based on a minimum pressure difference that can affect the vehicle behavior. Such a minimum pressure difference depends on the performance of the vehicle (a wide variety of factors) and may be adapted by testing or the like.
  • the wheel speed of the right front wheel 100FR related to the first system hydraulic circuit 201A and the second system hydraulic circuit based on the output signals of the wheel speed sensors 138FR, 138FL, 138RR, 138RL.
  • the target control value for the system with the smaller wheel speed decrease (sag) of the right front wheel 100FR and the left front wheel 100FL is set to the other system. It may be set higher (raised) than the target control value.
  • the target control value for the system with the smaller wheel speed reduction (sag) of the left rear wheel 100RL and the right rear wheel 100RR is set to be higher than the target control value for the other system. It is good also as setting high (raising).
  • the target control value is a hydraulic target value for the wheel cylinder pressure and the final target control value is a fixed value (for example, 5 Mpa)
  • the target control value raising amount ⁇ P is also fixed.
  • a value (for example, 0.2 Mpa) may be determined in advance.
  • the target control value raising amount ⁇ P may be varied in accordance with the magnitude of the difference in the reduction speed of the wheel speed.
  • the relationship between the difference between the wheel speed reduction speeds and the raised amount ⁇ P may be created in advance as a map.
  • the four-wheel automatic braking in step 1402 is typically executed under a situation where the driver does not operate the brake pedal 190. That is, the target control value used in step 1402 is a value (including a fixed value) determined based on factors other than the operation amount of the brake pedal 190.
  • the target control value used in step 1402 is a value (including a fixed value) determined based on factors other than the operation amount of the brake pedal 190.
  • the driver operates the brake pedal 190 after starting the four-wheel automatic braking for example, the operation of the brake pedal 190 may be ignored and the four-wheel automatic braking may be continued.
  • the driver operates the brake pedal 190 after starting the four-wheel automatic braking for example, when the master cylinder pressure becomes equal to or higher than a predetermined pressure, the normal braking may be performed.
  • the wheel cylinders 224FL It is good also as applying to 224FR, 224RL, 224RR.
  • the four-wheel automatic braking in step 1402 may be executed under a situation where the driver is operating the brake pedal 190.
  • the sudden braking command start condition may be varied depending on whether the driver operates the brake pedal 190 or not.
  • the TTC as a threshold value that satisfies the sudden braking command start condition may be changed to a long time (for example, 1.5 seconds).
  • the target control value used in step 1402 may be determined based on factors other than the operation amount of the brake pedal 190.
  • the holding solenoid valves 212FL, 212FR, 212RL, 212RR and the pressure reducing solenoid valves 214FL, 214FR, 214RL, 214RR are all maintained in the normal state. That is, the holding solenoid valves 212FL, 212FR, 212RL, and 212RR and the pressure reducing solenoid valves 214FL, 214FR, 214RL, and 214RR are individually controlled for each wheel in the vehicle stabilization control such as VSC.
  • the four-wheel automatic brake is control for each system, and different control is not executed in the same system. However, vehicle stabilization control such as ABS or VSC may be activated after the start of the four-wheel automatic braking in step 1402.
  • the four-wheel automatic brake may be stopped, or such other control may be executed while continuing the four-wheel automatic brake.
  • the M / C cut valves 206A and 206B are controlled in the same manner as in the four-wheel automatic braking, while the holding solenoid valves 212FL, 212FR, 212RL, 212RR and the pressure reducing solenoid valves 214FL, 214FR, 214RL, 214RR are used. It is good also as performing control according to the control law of ABS or vehicle stabilization control.
  • FIG. 15 is a diagram illustrating an example of a time series (target control value pattern) of target control values set for each of the first system hydraulic circuit 201A and the second system hydraulic circuit 201B.
  • the target control value is a hydraulic target value for the wheel cylinder pressure.
  • the time series of the values are indicated by dotted lines, and the actual wheel cylinder pressure (first system) of the wheel cylinder 224FR of the first system when controlled by these hydraulic target value patterns.
  • the time series of the actual hydraulic pressure) and the time series of the actual wheel cylinder pressure (second system actual hydraulic pressure) of the wheel cylinder 224FL of the second system are indicated by solid lines.
  • the first system hydraulic pressure target value increases toward the final first system hydraulic pressure target value (5 Mpa in this example) at the start of the sudden braking command.
  • the second system hydraulic pressure target value is the final second system hydraulic target value (5.2 Mpa in this example) that is raised by the raising amount ⁇ P from the final first system hydraulic target value at the start of the sudden braking command.
  • FIG. 16 is a diagram illustrating a simultaneous sequence according to a comparative example in which the same (common) target control value is applied to the first system hydraulic circuit 201A and the second system hydraulic circuit 201B.
  • both the first system hydraulic target value and the second system hydraulic target value increase toward the final hydraulic target value (5 Mpa in this example) at the start of the sudden braking command.
  • FIG. 16 due to the characteristic difference between the second system hydraulic circuit 201B and the first system hydraulic circuit 201A (difference in the amount of oil consumed due to the difference in piping length, design variation of various valves, etc.), FIG.
  • the difference between the wheel cylinder pressure of the wheel cylinder 224FL of the second system and the wheel cylinder pressure of the wheel cylinder 224FR of the first system is constant, as shown by the solid lines attached to the first system actual hydraulic pressure and the second system actual hydraulic pressure. It becomes larger than the value DTh .
  • the final second system hydraulic pressure target value is set to a value higher than the original final hydraulic pressure target value by the raised amount ⁇ P.
  • the wheel cylinder pressure of the first system wheel cylinder 224FR and the wheel cylinder pressure of the second system wheel cylinder 224FL can be increased in substantially the same manner.
  • the target control value is a hydraulic pressure target value with respect to the wheel cylinder pressure, and therefore the raising amount ⁇ P is a dimension of the hydraulic pressure.
  • the front wheel will be described, but the same may be applied to the rear wheel.
  • FIG. 17 is a diagram showing an example of the relationship between the vehicle speed and the wheel speed.
  • FIG. 17 shows an example of a change mode of the vehicle body speed Vx during actual emergency deceleration, an example of a change mode of the wheel speed VwFL of the left front wheel 100FL, and an example of a change mode of the wheel speed VwFR of the right front wheel 100FR.
  • the vehicle body speed Vx, the wheel speed VwFL of the left front wheel 100FL, and the wheel speed VwFR of the right front wheel 100FR shown in FIG. 17 may be calculated based on output signals of the wheel speed sensors 138FR, 138FL, 138RR, 138RL.
  • FIG. 18 is a diagram showing an example of the relationship between the slip ratio and the braking force.
  • 0.08 is shown as an example of the slip ratio that exhibits the maximum braking force
  • 8000 [N] is shown as an example of the maximum braking force.
  • Such a characteristic diagram may be obtained based on a test or calculation, or a design value may be used.
  • the slip ratio SFR of the right front wheel 100FR and the slip ratio SFL of the left front wheel 100FL are obtained from the following equations.
  • SFR (Vx ⁇ VwFR) / Vx
  • SFL (Vx ⁇ VwFL) / Vx
  • the braking force BFR and the braking force BFL are calculated by linear approximation as shown by the dotted line P in FIG. Also good.
  • This braking force difference B diff may be converted into a dimension of the hydraulic pressure P diff .
  • a relationship (characteristic) between a hydraulic pressure (for example, 7 Mpa) and a braking force necessary to realize a deceleration of 1 G (9.8 m / s 2 ) may be used.
  • the raising amount ⁇ P related to the left front wheel 100FL may be a hydraulic pressure P diff obtained by converting the braking force difference B diff .
  • the control device 10 is based on the output signals of the wheel speed sensors 138FR, 138FL, 138RR, 138RL and the characteristic diagram shown in FIG. 18, for example, in the process of step 1402 shown in FIG. Then, the raising amount ⁇ P may be calculated.
  • the relationship between the difference between the slip ratio SFR of the right front wheel 100FR and the slip ratio SFL of the left front wheel 100FL (or the braking force difference B diff or the difference between the wheel speed VwFL and the wheel speed VwFR) and the raising amount ⁇ P is determined in advance. It may be created as a map and stored in memory. For example, the map may be created by calculating the raising amount ⁇ P for a plurality of slip ratio differences.
  • control device 10 may calculate the slip ratio difference based on the output signals of the wheel speed sensors 138FR, 138FL, 138RR, 138RL, and read the raised amount ⁇ P corresponding to the calculated slip ratio difference.
  • an increase amount ⁇ P corresponding to a slip ratio difference that is not defined in the map is obtained by interpolating an increase amount ⁇ P corresponding to two slip ratio differences that are close to the difference. It may be calculated.
  • the wheel cylinder pressure sensor is not provided in the wheel cylinders 224FR, 224FL, 224RR, and 224RL. Even with such an inexpensive configuration, the vehicle stability during four-wheel automatic braking is improved by the feedforward control as described above, not by the feedback control based on the detection value of the wheel cylinder pressure sensor as described above. Is possible. However, the target control value may be fed back and set based on the output signals of the wheel speed sensors 138FR, 138FL, 138RR, and 138RL. In addition, this invention is applicable also to the structure provided with a wheel cylinder pressure sensor. In this case, the detected value of the wheel cylinder pressure sensor may be used as feedback control during four-wheel automatic braking, or the detected value of the wheel cylinder pressure sensor may not be used as feedback control during four-wheel automatic braking.
  • the pumps 260F and 260R are provided for each system, but one common pump may be provided for the two systems.
  • the reservoirs 250F and 250R are integrated into one, the pumps 260F and 260R are replaced with one common pump, and the discharge side of the common one pump is branched so that the pump flow path 210F, 210R may be formed.
  • the hydraulic circuit 200 ' the “first hydraulic pressure generation source” and the “second hydraulic pressure generation source” in the claims are realized by the one common pump.
  • one common pump may be provided with an accumulator.
  • the above-described embodiment relates to the hydraulic circuit 200 using the front and rear pipes and the hydraulic circuit 200 ′ using the X pipe, but the same idea as the hydraulic circuit 200 ′ using the X pipe is applied to the hydraulic circuit using the left and right pipes. be able to.
  • the illustrated hydraulic circuit 200 using the front and rear piping and the hydraulic circuit 200 ′ using the X piping are merely examples, and may be changed in various ways.
  • the hydraulic circuit 200 may be configured to turn on / off the flow of hydraulic pressure from the master cylinder 202 to the pumps 260F, 260R by providing suction solenoid valves in the flow paths 205F, 205R.
  • two check valves may be provided on the suction sides of the pumps 260F and 260R in the pump channels 210F and 210R from the reservoirs 250F and 250R, respectively, and the channels 205F and 205R may be connected between the two check valves, respectively. .
  • the pumps 260F and 260R suck and discharge the oil from the master cylinder 202 without passing through the reservoirs 250F and 250R.
  • the holding solenoid valves 212FL, 212FR, 212RL, 212RR and the pressure reducing solenoid valves 214FL, 214FR, 214RL, 214RR may be linear valves.
  • the structure which uses a common reservoir by the master cylinder 202 and the pumps 260F and 260R may be sufficient. These changes can be similarly made in the hydraulic circuit 200 '.
  • the M / C cut valves 206F and 206R are controlled in different modes during four-wheel automatic braking to control the wheel cylinder pressures of the front wheel cylinders 224FL and 224FR and the rear wheel wheel cylinders 224RL and 224RR.
  • the wheel cylinder pressure is increased, it is also possible to realize a similar pressure increasing mode by controlling the pumps 260F and 260R in different modes during four-wheel automatic braking.
  • the pumps 260F and 260R may be driven by separate motors, and the M / C cut valves 206F and 206R may be on / off valves.
  • the M / C cut valves 206F and 206R are closed, and the pump 260F and the pump 260R are controlled in different modes, that is, the rotational speed of the pump 260F (the discharge amount associated therewith).
  • the number of revolutions of pump 260R are controlled in different modes, so that boosting of wheel cylinders 224FL, 224FR, 224RL, 224RR can be realized in the same manner as in the above-described embodiment. Good.
  • These changes can be similarly made in the hydraulic circuit 200 '.
  • the M / C cut valves 206F and 206R are controlled in different modes during four-wheel automatic braking to control the wheel cylinder pressures of the front wheel cylinders 224FL and 224FR and the rear wheel wheel cylinders 224RL and 224RR.
  • 212RR and pressure-reducing solenoid valves 214RL and 214RR can be controlled in different modes to achieve the same boosting mode.
  • the M / C cut valves 206F and 206R may be on / off valves. More specifically, during four-wheel automatic braking, the M / C cut valves 206F and 206R are closed, the holding solenoid valves 212FL and 212FR and the pressure reducing solenoid valves 214FL and 214FR related to the front wheel system hydraulic circuit 201F, and the rear wheel system hydraulic pressure. By controlling the holding solenoid valves 212RL and 212RR and the pressure reducing solenoid valves 214RL and 214RR related to the circuit 201R in different modes, the boosting of the wheel cylinders 224FL, 224FR, 224RL and 224RR is realized in the same manner as in the above-described embodiment.
  • the holding solenoid valves 212FL and 212FR related to the front wheel system hydraulic circuit 201F are controlled in the same manner, and the pressure reducing solenoid valves 214FL and 214FR related to the front wheel system hydraulic circuit 201F are controlled in the same manner.
  • holding solenoid valves 212RL and 212RR related to rear wheel system hydraulic circuit 201R are controlled in the same manner, and pressure reducing solenoid valves 214RL and 214RR related to rear wheel system hydraulic circuit 201R are controlled in the same manner.
  • a circuit configuration typically used in a brake-by-wire system represented by ECB may be employed.
  • ECB Electrical Control Braking System
  • a circuit configuration as disclosed in Japanese Patent Application Laid-Open No. 2006-103547 may be employed.
  • the “first hydraulic pressure generation source” and the “second hydraulic pressure generation source” in the claims are realized by the common one pump.
  • the M / C cut valve may be an on / off valve.
  • the front radar sensor 134 is used for detecting a front obstacle, but a camera may be used instead of or in addition to the front radar sensor 134.
  • the front obstacle may be detected in cooperation with the front radar sensor 134 and the camera.

Abstract

La présente invention est pourvue : d'une voie hydraulique destinée à un premier système ; d'une voie hydraulique destinée à un second système ; d'une première source de pression hydraulique qui produit une pression hydraulique apportée au cylindre de roue d'une première roue ; d'une première soupape qui fait varier la pression de cylindre de roue de la première roue ; d'une deuxième source de pression hydraulique qui produit une pression hydraulique apportée au cylindre de roue d'une seconde roue au moyen de la voie hydraulique destinée au second système ; d'une seconde soupape qui fait varier la pression de cylindre de roue de la seconde roue ; d'une troisième source de pression hydraulique qui produit une pression hydraulique en fonction de l'action exercée sur la pédale de frein par le conducteur ; et d'un dispositif de commande qui exécute une commande de freinage d'urgence consistant, lorsqu'un ralentissement d'urgence prédéfini est demandé, à commander la première soupape et la seconde soupape par le biais de modes de réalisation différents, et sur la base de la pression hydraulique produite par la première source de pression hydraulique et de la seconde source de pression hydraulique, à augmenter la pression de cylindre de roue de la première roue et la pression de cylindre de roue de la seconde roue.
PCT/JP2011/061107 2011-05-13 2011-05-13 Dispositif de freinage de véhicule WO2012157050A1 (fr)

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US20160368465A1 (en) * 2015-06-22 2016-12-22 Honda Motor Co., Ltd. Vehicle brake system
JP2017007487A (ja) * 2015-06-22 2017-01-12 本田技研工業株式会社 車両用制動装置

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JPH1120647A (ja) * 1997-06-30 1999-01-26 Aisin Seiki Co Ltd 車両用ブレーキ液圧制御装置
JP2002087234A (ja) * 2000-09-18 2002-03-27 Bosch Braking Systems Co Ltd 自動車用ブレーキシステムにおける液圧バランス方法
JP2003165428A (ja) * 2001-11-30 2003-06-10 Daihatsu Motor Co Ltd 車両制動制御装置および方法
JP2006506271A (ja) * 2002-11-16 2006-02-23 コンティネンタル・テーベス・アクチエンゲゼルシヤフト・ウント・コンパニー・オッフェネ・ハンデルスゲゼルシヤフト 自動車のためのブレーキシステムをコントロールするための方法及び装置
JP2006160051A (ja) * 2004-12-07 2006-06-22 Toyota Motor Corp 車輌の制動力制御装置
JP2007216773A (ja) * 2006-02-15 2007-08-30 Advics:Kk 車両用ブレーキ制御装置

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JPH1120647A (ja) * 1997-06-30 1999-01-26 Aisin Seiki Co Ltd 車両用ブレーキ液圧制御装置
JP2002087234A (ja) * 2000-09-18 2002-03-27 Bosch Braking Systems Co Ltd 自動車用ブレーキシステムにおける液圧バランス方法
JP2003165428A (ja) * 2001-11-30 2003-06-10 Daihatsu Motor Co Ltd 車両制動制御装置および方法
JP2006506271A (ja) * 2002-11-16 2006-02-23 コンティネンタル・テーベス・アクチエンゲゼルシヤフト・ウント・コンパニー・オッフェネ・ハンデルスゲゼルシヤフト 自動車のためのブレーキシステムをコントロールするための方法及び装置
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160368465A1 (en) * 2015-06-22 2016-12-22 Honda Motor Co., Ltd. Vehicle brake system
JP2017007487A (ja) * 2015-06-22 2017-01-12 本田技研工業株式会社 車両用制動装置
US10053066B2 (en) * 2015-06-22 2018-08-21 Honda Motor Co., Ltd. Vehicle brake system
US10266161B2 (en) 2015-06-22 2019-04-23 Honda Motor Co., Ltd. Vehicle brake system

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