WO2013136837A1 - 制動力制御装置 - Google Patents
制動力制御装置 Download PDFInfo
- Publication number
- WO2013136837A1 WO2013136837A1 PCT/JP2013/050842 JP2013050842W WO2013136837A1 WO 2013136837 A1 WO2013136837 A1 WO 2013136837A1 JP 2013050842 W JP2013050842 W JP 2013050842W WO 2013136837 A1 WO2013136837 A1 WO 2013136837A1
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- WO
- WIPO (PCT)
- Prior art keywords
- braking force
- change speed
- vehicle
- upper limit
- rear wheel
- Prior art date
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Classifications
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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
- 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
- B60T8/17—Using electrical or electronic regulation means to control braking
- B60T8/176—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS
- B60T8/1761—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS responsive to wheel or brake dynamics, e.g. wheel slip, wheel acceleration or rate of change of brake fluid pressure
- B60T8/17616—Microprocessor-based systems
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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
- 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
- B60T8/17—Using electrical or electronic regulation means to control braking
- B60T8/176—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS
- B60T8/1764—Regulation during travel on surface with different coefficients of friction, e.g. between left and right sides, mu-split or between front and rear
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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
- 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
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/72—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration responsive to a difference between a speed condition, e.g. deceleration, and a fixed reference
Definitions
- the present invention relates to a braking force control device.
- Patent Document 1 discloses that when the vehicle body speed is a predetermined value or more and the vehicle body deceleration is a predetermined value or more, based on the difference between the maximum front wheel speed and the wheel speed of each rear wheel, There is disclosed a vehicle brake device that independently controls the braking force of the left and right rear wheels so that the braking force distribution between the rear wheel and the rear wheel can be approximated to an ideal curve.
- the vehicle brake device described in Patent Document 1 as described above is, for example, a case where the tire characteristics ( ⁇ characteristics) of the left and right wheels of the vehicle are different or the friction coefficient ( ⁇ ) of the left and right wheels of the vehicle are different or the friction coefficient ( ⁇ ).
- ⁇ characteristics tire characteristics of the left and right wheels of the vehicle are different or the friction coefficient
- the present invention has been made in view of the above circumstances, and an object thereof is to provide a braking force control device that can stabilize the behavior of a vehicle.
- a braking force control device includes a braking device capable of individually adjusting a braking force generated on each wheel of the vehicle, and controls the braking device to control the left and right wheels of the vehicle.
- a control device capable of executing a braking force distribution control for individually controlling the braking force of the left and right wheels so that the slip state is equivalent, and the control device is a deviation of the braking force of the left and right wheels.
- the braking force distribution control is executed based on a change speed upper limit value of a change speed of a certain left / right braking force deviation.
- the control device increases the braking force of the left and right wheels when the change speed of the left / right braking force deviation is larger than the change speed upper limit value in the braking force distribution control.
- Control that reduces the braking force of the left and right wheels may be prioritized over control.
- the control device reduces the braking force of the left and right wheels when the change speed of the left and right braking force deviation is larger than the change speed upper limit value in the braking force distribution control.
- Control that increases the braking force of the left and right wheels may be prioritized over control.
- the change speed upper limit value can be made smaller as the deceleration of the vehicle is larger.
- the change speed upper limit value can be increased as the change speed of the deceleration of the vehicle increases.
- the change speed upper limit value can be made smaller as the traveling speed of the vehicle is higher.
- the change speed upper limit value can be increased as the change speed of the lateral movement of the vehicle is increased.
- the change speed upper limit value is relatively higher when a wheel having a larger braking force among the left and right wheels is a wheel on the same direction side as the lateral movement direction of the vehicle. It can be made relatively small when the wheel on the side of the left and right wheels that has the larger braking force is the wheel on the side opposite to the direction of the lateral movement of the vehicle.
- the change speed upper limit value is relatively large when the movement of the vehicle due to the change speed of the left / right braking force deviation is in a direction to cancel the lateral movement of the vehicle.
- the movement of the vehicle due to the change speed of the power deviation is in a direction that increases the lateral movement of the vehicle, the movement can be made relatively small.
- the wheels of the vehicle to be controlled by the braking force distribution control are the left and right wheels of the rear wheel of the vehicle, and the change speed upper limit value is the value of the front wheel of the vehicle. The larger the deviation of the wheel speeds of the left and right wheels or the change speed of the deviation of the wheel speeds, the greater the difference.
- the braking force control device has an effect that the behavior of the vehicle can be stabilized.
- FIG. 1 is a schematic configuration diagram of a vehicle to which the braking force control apparatus according to the first embodiment is applied.
- FIG. 2 is a flowchart illustrating an example of braking force distribution control by the ECU of the braking force control apparatus according to the first embodiment.
- FIG. 3 is a flowchart for explaining an example of braking force distribution control by the ECU of the braking force control apparatus according to the modification.
- FIG. 4 is a diagram showing an example of a change speed upper limit value map of the braking force control apparatus according to the second embodiment.
- FIG. 5 is a diagram illustrating an example of a change speed upper limit value map of the braking force control apparatus according to the third embodiment.
- FIG. 6 is a diagram illustrating an example of a change speed upper limit value map of the braking force control apparatus according to the fourth embodiment.
- FIG. 7 is a diagram illustrating an example of a change speed upper limit value map of the braking force control apparatus according to the fifth embodiment.
- FIG. 8 is a schematic diagram for explaining the change speed upper limit value of the braking force control apparatus according to the sixth embodiment.
- FIG. 9 is a schematic diagram for explaining the change speed upper limit value of the braking force control apparatus according to the sixth embodiment.
- FIG. 10 is a diagram illustrating an example of a change speed upper limit value map of the braking force control apparatus according to the seventh embodiment.
- FIG. 1 is a schematic configuration diagram of a vehicle to which a braking force control device according to a first embodiment is applied
- FIG. 2 is a flowchart illustrating an example of braking force distribution control by an ECU of the braking force control device according to the first embodiment
- FIG. 3 is a flowchart for explaining an example of braking force distribution control by the ECU of the braking force control apparatus according to the modification.
- the braking force control apparatus 1001 of this embodiment illustrated in FIG. 1 may be referred to as the left and right wheels 3 of the vehicle 2, typically the left and right wheels on the rear side of the vehicle 2 (hereinafter referred to as “rear wheels”). )
- a braking force distribution device capable of executing a braking force distribution control for independently and independently controlling the braking force of the wheel 3 so that the slip state (slip rate) of 3 is equal. Then, the braking force control device 1001 sets a change speed upper limit value that is an upper limit value of the change speed of the braking force difference (braking force deviation) between the right and left rear wheels 3 to be allowed in this braking force distribution control.
- the braking force control apparatus 1001 is configured such that when the tire characteristics ( ⁇ characteristics) of the left and right wheels 3 of the vehicle 2 are different or the friction coefficient (road surface ⁇ ) of the road surface on which the left and right wheels 3 are grounded are different. The behavior of the vehicle 2 is stabilized when the vehicle 2 is traveling on a so-called ⁇ split road.
- the braking force control apparatus 1001 prevents the change rate of the braking force difference from increasing further when the change rate of the braking force difference becomes larger than the change rate upper limit value in the braking force distribution control.
- the braking force control device 1001 gives priority to the control for reducing the braking force of the left and right wheels 3 over the control for maintaining the braking force of the left and right wheels 3 and increasing the braking force of the left and right wheels 3.
- priority is given to the control for increasing the braking force of the left and right wheels 3 over the control for reducing the braking force of the left and right wheels 3, so that the changing speed of the braking force difference is not further increased.
- the braking force control apparatus 1001 of this embodiment is a braking control system that is mounted on the vehicle 2 as shown in FIG. 1 and brakes the vehicle 2.
- the braking force control device 1001 is typically a system that controls the slipping state of each wheel 3 by controlling the braking force generated on the wheel 3 of the vehicle 2 and stabilizes the behavior of the vehicle 2.
- the vehicle 2 includes, as wheels 3, a left front wheel (left front wheel 3) 3FL, a right front wheel (right front wheel 3) 3FR, a left rear wheel (left rear wheel 3) 3RL, and a right rear wheel (right rear side).
- the wheel 3) is provided with 3RR, but these are simply referred to as the wheel 3 when it is not necessary to separate them.
- the braking force control device 1001 includes an accelerator pedal 4, a power source 5, a brake pedal 6, a braking device 7, an ECU 8 as a control device, and the like.
- the power source 5 generates power (torque) according to the operation of the accelerator pedal 4 by the driver, and this power is transmitted to the wheels 3 via a power transmission device (not shown). Generate driving force.
- the vehicle 2 generates a braking force on the wheel 3 by operating the braking device 7 according to the operation of the brake pedal 6 by the driver.
- the power source 5 is a driving power source such as an internal combustion engine or an electric motor.
- the braking device 7 can individually adjust the braking force generated on each wheel 3 of the vehicle 2.
- the brake device 7 is a variety of hydraulic brake devices in which brake oil, which is a working fluid, is filled in a hydraulic path connected from the master cylinder 9 to the wheel cylinder 11 via a hydraulic control device (hydraulic actuator) 10.
- the hydraulic braking unit 12 operates according to the braking pressure supplied to the wheel cylinder 11 to generate a pressure braking force on the wheel 3.
- the brake device 7 basically has a master cylinder pressure (operating pressure) applied to the brake oil by the master cylinder 9 according to the pedal depression force (operating force) acting on the brake pedal 6 by the driver operating the brake pedal 6.
- the hydraulic braking unit 12 is activated by a pressure corresponding to the master cylinder pressure acting as a wheel cylinder pressure (braking pressure) in each wheel cylinder 11.
- Each of the hydraulic braking units 12 has a brake pad abutting against and pressed against the disk rotor, so that a predetermined rotational resistance force according to the wheel cylinder pressure acts on the disk rotor rotating with the wheel 3.
- a braking force can be applied to the wheel 3 rotating integrally therewith.
- the wheel cylinder pressure of the braking device 7 is appropriately adjusted by the hydraulic control device 10 according to the operating state.
- the hydraulic control device 10 individually adjusts the braking force generated in each wheel 3 by individually increasing, reducing, and holding the wheel cylinder pressure independently.
- the hydraulic control device 10 is provided on the hydraulic path of the brake oil that connects the master cylinder 9 and the wheel cylinder 11, and increases or decreases the hydraulic pressure in each wheel cylinder 11 by control by the ECU 8 separately from the brake operation of the brake pedal 6. Then, the braking force applied to each wheel 3 is controlled.
- the hydraulic control device 10 includes, for example, a plurality of pipes, an oil reservoir, an oil pump, each hydraulic pipe connected to each wheel cylinder 11 provided in each wheel 3, and the hydraulic pressure of each hydraulic pipe is increased, reduced, It comprises a plurality of electromagnetic valves for holding, and is controlled by the ECU 8.
- the hydraulic control device 10 functions as a working fluid pressure adjusting unit that transmits the hydraulic pressure (master cylinder pressure) in the hydraulic piping as it is or pressurizes and depressurizes it to each wheel cylinder 11 described later in accordance with a control command of the ECU 8.
- the hydraulic control device 10 is driven by, for example, an oil pump or a predetermined electromagnetic valve in accordance with a control command from the ECU 8, so that the wheel cylinder is controlled according to the amount of operation (depression amount) of the brake pedal 6 by the driver.
- the wheel cylinder pressure acting on the pressure 11 can be adjusted.
- the hydraulic control device 10 acts on the wheel cylinder 11 by driving an oil pump or a predetermined electromagnetic valve according to a control command of the ECU 8, for example. It is possible to operate in a pressure increasing mode in which the wheel cylinder pressure is increased, a holding mode in which the wheel cylinder pressure is maintained substantially constant, a pressure reducing mode in which pressure is reduced.
- the hydraulic control device 10 can set the mode individually for each wheel cylinder 11 of each wheel 3 according to the traveling state of the vehicle 2 under the control of the ECU 8. That is, the hydraulic control device 10 can individually adjust the braking force acting on each wheel 3 according to the traveling state of the vehicle 2 regardless of the operation of the brake pedal 6 by the driver.
- the ECU 8 controls driving of each part of the vehicle 2 and includes an electronic circuit mainly composed of a known microcomputer including a CPU, a ROM, a RAM, and an interface.
- the ECU 8 for example, each wheel speed sensor 13 that detects the rotational speed of each wheel 3, a longitudinal acceleration sensor 14 that detects acceleration in the front-rear direction (traveling direction) generated in the vehicle body of the vehicle 2, and a yaw rate that detects the yaw rate of the vehicle 2.
- lateral acceleration sensor 16 that detects acceleration in the lateral direction (direction intersecting (orthogonal) with the traveling direction) generated in the vehicle body of vehicle 2
- steering angle sensor 17 that detects the steering angle of vehicle 2
- master cylinder pressure is detected
- Various sensors and detection devices attached to various parts of the vehicle 2 such as the master cylinder pressure sensor 18 that detects the wheel cylinder pressure of each wheel 3 and the wheel cylinder pressure sensor 19 that detects the wheel cylinder pressure of each wheel 3 are electrically connected to correspond to the detection result.
- the electrical signal is input.
- the wheel cylinder pressure detected by the wheel cylinder pressure sensor 19 is a value corresponding to the magnitude of the braking force generated by the hydraulic braking unit 12 of each wheel 3.
- the ECU 8 executes the stored control program on the basis of various input signals and various maps input from various sensors, thereby allowing each part of the vehicle 2 such as the power source 5 and the hydraulic control device 10 of the braking device 7 to be executed.
- Drive signals are output to control these drives.
- the ECU8 of this embodiment controls the hydraulic control apparatus 10 according to the driving
- the ECU 8 can execute braking force distribution control for controlling the braking device 7 and individually controlling the slip state of the wheels 3. Thereby, the braking force control apparatus 1001 can control the behavior of the vehicle 2.
- the ECU 8 controls the braking device 7 to individually control the braking force of the left and right wheels 3 so that the slip states of the left and right wheels 3 of the vehicle 2 are equal. Execute control.
- the ECU 8 controls the braking force generated in each wheel 3 by adjusting the wheel cylinder pressure of each wheel 3 (hereinafter sometimes simply referred to as “brake hydraulic pressure”), thereby causing the slip of the wheel 3 to slip.
- the state, for example, the slip rate of the wheel 3 is controlled.
- the slip ratio is an index representing slip (slip) between the tire of the wheel 3 and the road surface.
- the ECU 8 typically controls the hydraulic control device 10 of the braking device 7 so that the left rear wheel 3RL and the left rear wheel 3RR, which are the left and right rear wheels, have the same slip ratio.
- the brake hydraulic pressure of the right rear wheel 3RR is individually controlled on the left and right sides.
- the ECU 8 basically controls the left rear wheel 3RL and the right rear wheel 3RR so that the slip ratios of the left rear wheel 3RL and the right rear wheel 3RR become the target slip ratios in the braking force distribution control, respectively.
- the brake hydraulic pressure is controlled individually.
- ECU8 controls the braking force distribution of each wheel 3, and controls the braking force which arises in left rear wheel 3RL and right rear wheel 3RR.
- the ECU 8 reduces the brake hydraulic pressure and reduces the braking force when the actual slip rate becomes larger than the target slip rate in each of the left rear wheel 3RL and the right rear wheel 3RR.
- the brake hydraulic pressure is increased to increase the braking force.
- the ECU 8 periodically repeats this to control the slip ratios of the left rear wheel 3RL and the right rear wheel 3RR to be equal, and thereby the stability of the vehicle 2 can be improved.
- the target slip ratio is equivalent to, for example, the actual slip ratio of the left front wheel 3FL and the right front wheel 3FR when the braking device 7 generates a braking force on each wheel 3 according to the brake pedal 6 by the driver. It is set according to the slip ratio.
- the target slip ratio may have a predetermined range.
- the ECU 8 can obtain the slip ratio of the wheel 3 using various known methods such as obtaining the slip ratio of each wheel 3 based on the wheel speed of the wheel 3 and the vehicle speed that is the traveling speed of the vehicle 2. That's fine. As an example, the ECU 8 calculates the following formula (1) based on the wheel speed Vw of each wheel 3 detected by each wheel speed sensor 13 and the vehicle speed Vr of the vehicle 2 estimated from the wheel speed Vw of each wheel 3.
- the slip ratio ⁇ is calculated for each wheel 3 based on each detected value by each wheel speed sensor 13.
- the vehicle speed may be detected by a vehicle speed sensor provided separately from each wheel speed sensor 13.
- ⁇ (Vr ⁇ Vw) / Vr (1)
- the ECU 8 of the present embodiment changes the rate of change of the left / right braking force difference (left / right braking force deviation) (hereinafter, sometimes referred to as “left / right braking force difference change rate”).
- the braking force distribution control is executed based on the change speed upper limit value that is the upper limit value.
- the left / right braking force difference corresponds to a difference (deviation) in braking force between the left rear wheel 3RL and the right rear wheel 3RR.
- the change speed of the left / right braking force difference corresponds to the amount of change in the left / right braking force difference per unit time.
- the change speed upper limit value set for the change speed of the left and right braking force difference between the left rear wheel 3RL and the right rear wheel 3RR is set in advance according to the allowable braking force difference change speed.
- the change speed upper limit value is set in advance according to the slip state of the wheel 3, the behavioral stability of the vehicle 2, and the like based on the actual vehicle evaluation and the like, and is stored in the storage unit of the ECU 8.
- the braking force control apparatus 1001 stabilizes the behavior of the vehicle 2 even when, for example, the tire characteristics of the left and right wheels 3 of the vehicle 2 are different or the vehicle 2 is traveling on a ⁇ split road. It can be made.
- the vehicle 2 when the vehicle 2 is equipped with tires having different tire characteristics between the left wheel 3 and the right wheel 3 or in the case of ⁇ split road braking in which the friction coefficient of the road surface on which the left and right wheels 3 are grounded is different, The behavior may be disturbed.
- the vehicle 2 controls the above-described control so that the slip ratios of the left rear wheel 3RL and the right rear wheel 3RR are equal. Even if the power distribution control is executed, there is a possibility that proper braking force distribution cannot be obtained. As a result, the vehicle 2 may be deflected due to an unintended braking force difference.
- a tire with a high grip (tire with high ⁇ characteristics) is attached to the left rear wheel 3RL and a tire with a low grip (tire with low ⁇ characteristics) is attached to the right rear wheel 3RR.
- the braking force of the right rear wheel 3RR and the left rear wheel 3RL is adjusted by the braking force distribution control so that the slip ratios of the left rear wheel 3RL and the right rear wheel 3RR are equal, the actual braking force distribution is , [Braking force of right rear wheel 3RR] ⁇ [braking force of left rear wheel 3RL].
- the vehicle 2 may become a braking force distribution that further deflects to the left and tries to turn.
- the ECU 8 executes the braking force distribution control based on the change speed upper limit value of the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR.
- the ECU 8 applies the braking force so that the left / right braking force difference change rate does not increase any more when the left / right braking force difference change rate of the left rear wheel 3RL and the right rear wheel 3RR is larger than the change rate upper limit value.
- the ECU 8 of the present embodiment when the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR are larger than the change speed upper limit value, the braking force of the left rear wheel 3RL and the right rear wheel 3RR.
- the control for reducing the braking force of the left rear wheel 3RL and the right rear wheel 3RR is prioritized over the control for increasing. That is, during execution of the braking force distribution control, the ECU 8 determines the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR when it is requested to apply a left / right braking force difference at a change speed larger than the change speed upper limit value.
- the pressure increase is limited and the braking force is not increased (the braking force increase is stopped), while the lowering of the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR is preferentially allowed and the braking force is reduced preferentially.
- the ECU 8 prohibits the braking force increase request itself at the time of the braking force increase request for either the left rear wheel 3RL or the right rear wheel 3RR, and does not output the braking force increase request, or the braking force request value Does not increase.
- the ECU 8 allows the braking force reduction request at the time of a braking force reduction request for either the left rear wheel 3RL or the right rear wheel 3RR, and decreases the braking force request value as usual.
- the ECU 8 can restrict the braking force distribution control so that the left / right braking force difference change speed does not increase any more, and the braking force difference can fall within an allowable range.
- the amount of change in the left and right braking force difference is the rate of change of the braking force.
- the range should not be larger than the upper limit.
- the braking force control device 1001 configured as described above executes the braking force distribution control based on the upper limit change rate value of the left / right braking force difference change rate of the left rear wheel 3RL and the right rear wheel 3RR.
- the braking force distribution control is limited so that the left and right braking force difference change speeds do not increase any more. Therefore, the braking force control device 1001 adjusts the braking force of the right rear wheel 3RR and the left rear wheel 3RL individually in the braking force distribution control so that the slip ratios of the left rear wheel 3RL and the right rear wheel 3RR are equal.
- the braking force control apparatus 1001 can optimize the right and left braking force distribution, and can suppress the occurrence of deflection and turning of the vehicle 2 due to an unintended left and right braking force difference.
- the vehicle behavior can be suppressed to a minimum, and for example, the driver can perform corrective steering without a sense of incongruity.
- the braking force control apparatus 1001 is disturbed by the behavior of the vehicle 2 even when the tire characteristics of the left and right wheels 3 of the vehicle 2 are different or when the vehicle 2 is traveling on a ⁇ split road. Can be minimized.
- the braking force control apparatus 1001 does not increase the braking force of the left rear wheel 3RL and the right rear wheel 3RR while the left and right braking force difference change speed has reached the change speed upper limit value, while the left rear wheel 3RL,
- the braking force of the rear wheel 3RR is preferentially reduced.
- the braking force control device 1001 can set the braking force on the inner wheel side during deflection or turning of the left rear wheel 3RL and the right rear wheel 3RR in a state where the left / right braking force difference changing speed reaches the change speed upper limit value.
- the braking force control apparatus 1001 can set the left rear wheel 3RL and the right rear wheel 3RR to an appropriate slip ratio while keeping the left / right braking force difference change speed within an allowable range, and the left rear wheel 3RL and the right rear wheel. It is possible to prevent 3RR from being locked and to ensure the directional stability of the vehicle 2 and the like.
- the vehicle 2 has its deflection and turning direction determined according to, for example, the difference between the left and right braking force, the tire characteristics of the left and right wheels 3, the friction coefficient of the road surface on which the left and right wheels 3 are grounded, and the inner wheel, The outer ring will be determined.
- braking force distribution control by the ECU 8 will be described with reference to the flowchart of FIG. Note that these control routines are repeatedly executed at a control cycle of several ms to several tens of ms. Further, the braking force distribution control of the present embodiment is individually executed for the left rear wheel 3RL and the right rear wheel 3RR. In the following description, of the left rear wheel 3RL and the right rear wheel 3RR, the wheel 3 that is subject to braking force distribution control is referred to as a control target rear wheel.
- ECU8 determines whether it is currently braking based on the detection result etc. by wheel cylinder pressure sensor 19 (ST101). When it is determined that the ECU 8 is not currently braking (ST101: No), the ECU 8 ends the current control cycle and shifts to the next control cycle.
- the ECU 8 determines whether the brake hydraulic pressure of the rear wheel to be controlled is being held based on the detection result by the wheel cylinder pressure sensor 19 (ST102). ).
- the ECU 8 determines that the brake hydraulic pressure of the rear wheel to be controlled is not being held (ST102: No), whether the slip ratio ⁇ of the rear wheel to be controlled is greater than the threshold A based on the detection result of the wheel speed sensor 13 or the like. It is determined whether or not (ST103).
- the threshold A is set according to the target slip rate described above, for example.
- the ECU 8 determines that the slip ratio ⁇ of the rear wheel to be controlled is equal to or less than the threshold value A (ST103: No). If the ECU 8 determines that the slip ratio ⁇ of the rear wheel to be controlled is equal to or less than the threshold value A (ST103: No), the ECU 8 ends the current control cycle and shifts to the next control cycle. When the ECU 8 determines that the slip ratio ⁇ of the rear wheel to be controlled is larger than the threshold A (ST103: Yes), the ECU 8 controls the hydraulic control device 10 to maintain the brake hydraulic pressure of the rear wheel to be controlled. Holding the braking force (ST104), the current control cycle is terminated, and the next control cycle is started.
- the slip ratio ⁇ of the rear wheel to be controlled is a threshold based on the detection result of the wheel speed sensor 13. It is determined whether it is larger than B (ST105).
- the threshold value B is set according to, for example, the target slip ratio described above, similarly to the threshold value A described above.
- the slip rate ⁇ of the rear wheel to be controlled is equal to or less than the threshold value B (ST105: No)
- the slip rate ⁇ of the rear wheel to be controlled is greater than the threshold value C based on the detection result of the wheel speed sensor 13. It is determined whether it is small (ST106).
- the threshold value C is set according to, for example, the target slip ratio described above, similarly to the threshold values A and B described above.
- the threshold value C is set based on a predetermined hysteresis with respect to the threshold value B in order to suppress control hunting.
- the ECU 8 determines that the slip ratio ⁇ of the control target rear wheel is equal to or greater than the threshold C (ST106: No)
- the ECU 8 proceeds to ST104 and controls the hydraulic control device 10 to hold the brake hydraulic pressure of the control target rear wheel.
- the ECU 8 determines that the slip ratio ⁇ of the rear wheel to be controlled is smaller than the threshold C (ST106: Yes)
- the ECU 8 determines the current left rear wheel 3RL, right rear wheel 3RR based on the detection result of the wheel cylinder pressure sensor 19 and the like. It is determined whether or not the left and right braking force difference change speed is greater than the threshold value D1 (ST107).
- the threshold value D1 is set according to the above upper limit value.
- the ECU 8 determines that the right and left braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR are equal to or less than the threshold value D1 (ST107: No)
- the ECU 8 controls the hydraulic control device 10 to control the rear wheel to be controlled.
- the brake hydraulic pressure is increased to increase the braking force of the rear wheel to be controlled (ST108), the current control cycle is terminated, and the next control cycle is started.
- the ECU 8 determines whether or not the controlled rear wheel is an outer wheel. (ST109). In this case, in the following control, the ECU 8 gives priority to the pressure reduction of the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR, and restricts the increase of the brake hydraulic pressure, thereby changing the left-right braking force difference change speed to the change speed upper limit value.
- the braking force is adjusted by adjusting the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR while being housed inside.
- the ECU 8 controls the hydraulic control device 10 to increase the brake hydraulic pressure of the control target rear wheel (ST110).
- the ECU 8 has a brake hydraulic pressure that is not the main control target rear wheel.
- the pressure reduction and the reduction of the braking force are given priority, and the increase of the brake hydraulic pressure and the increase of the braking force of the rear wheel to be controlled are restricted.
- the ECU 8 suppresses the left / right braking force difference change speed from becoming greater than or equal to the change speed upper limit value.
- the ECU 8 increases the brake hydraulic pressure regardless of the state of the left rear wheel 3RL and the right rear wheel 3RR that is not the control target rear wheel, The increase in braking force is prohibited, the hydraulic control device 10 is controlled to hold the brake hydraulic pressure of the rear wheel to be controlled, the braking force of the rear wheel to be controlled is held (ST111), and the current control cycle is terminated. Transition to the next control cycle.
- the ECU 8 can minimize the occurrence of disturbance in the behavior of the vehicle 2 while suppressing the left / right braking force difference change speed from exceeding the change speed upper limit value. .
- the ECU 8 determines in ST105 that the slip ratio ⁇ of the rear wheel to be controlled is greater than the threshold B (ST105: Yes)
- the ECU 8 determines the current left rear wheel 3RL, It is determined whether or not the right / left braking force difference change speed of the right rear wheel 3RR is larger than the threshold value D1 (ST112).
- the ECU 8 determines that the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR are equal to or less than the threshold value D1 (ST112: No)
- the ECU 8 controls the hydraulic control device 10 to control the rear wheel to be controlled.
- the brake hydraulic pressure is reduced to reduce the braking force of the rear wheel to be controlled (ST113), the current control cycle is terminated, and the next control cycle is started.
- the ECU 8 determines whether or not the control target rear wheel is an inner wheel when the current left rear wheel 3RL and the right rear wheel 3RR determine that the left / right braking force difference change speed is greater than the threshold value D1 (ST112: Yes). (ST114). In this case, in the following control, the ECU 8 gives priority to the pressure reduction of the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR, and restricts the increase of the brake hydraulic pressure, thereby changing the left-right braking force difference change speed to the change speed upper limit value. The braking force is adjusted by adjusting the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR while being housed inside.
- the ECU 8 controls the hydraulic control device 10 to reduce the brake hydraulic pressure of the control target rear wheel (ST115).
- the ECU 8 brakes the brake that is not the main control target rear wheel.
- the increase in hydraulic pressure and the increase in braking force are restricted, and priority is given to reducing the brake hydraulic pressure and reducing the braking force of the rear wheel to be controlled.
- the ECU 8 suppresses the left / right braking force difference change speed from becoming greater than or equal to the change speed upper limit value.
- the ECU 8 controls the hydraulic control device 10 regardless of the state of the left rear wheel 3RL and the right rear wheel 3RR that is not the control target rear wheel. Then, the brake hydraulic pressure of both rear wheels (left rear wheel 3RL, right rear wheel 3RR) is reduced to reduce the braking force of both rear wheels at the same time (ST116), and the current control cycle is terminated and the next control cycle is completed. Migrate to As a result, the ECU 8 can minimize the occurrence of disturbance in the behavior of the vehicle 2 while suppressing the left / right braking force difference change speed from exceeding the change speed upper limit value. .
- the braking device 7 and the ECU 8 are provided.
- the braking device 7 can individually adjust the braking force generated on each wheel 3 of the vehicle 2.
- the ECU 8 can execute the braking force distribution control for controlling the braking device 7 and individually controlling the braking force of the left and right wheels 3 so that the slip states of the left and right wheels 3 of the vehicle 2 are equal.
- the ECU 8 executes the braking force distribution control based on the change speed upper limit value of the change speed of the left and right braking force deviation that is the deviation of the braking force of the left and right wheels 3. Therefore, the braking force control device 1001 performs the behavior of the vehicle 2 by the braking force distribution control even when the tire characteristics of the left and right wheels 3 of the vehicle 2 are different or when the vehicle 2 is traveling on the ⁇ split road. Can be stabilized.
- the ECU 8 When the ECU 8 described above executes the braking force distribution control, the ECU 8 further performs a left-right braking force difference (left-right braking force deviation) in addition to the braking force distribution control based on the change speed upper limit value described above.
- the braking force distribution control based on the braking force difference upper limit value which is the upper limit value of, may be executed.
- the ECU 8 complements each control by executing in parallel the braking force distribution control based on the change speed upper limit value and the braking force distribution control based on the braking force difference upper limit value. It may be.
- the ECU 8 determines that the left rear wheel 3RL and the right rear wheel 3RR when the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR are larger than the change speed upper limit value.
- the control for reducing the braking force of the left rear wheel 3RL and the right rear wheel 3RR is given priority over the control for increasing the braking force of the vehicle, the present invention is not limited to this.
- the ECU 8 may limit the braking force distribution control so that the rate of change in the left / right braking force difference does not increase any more.
- the ECU 8 holds the braking force of the left and right wheels 3 or
- the braking force distribution control may be limited by giving priority to the control for increasing the braking force.
- the ECU 8 determines that the left rear wheel 3RL and the right rear wheel when the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR are larger than the change speed upper limit value.
- Control for increasing the braking force of the left rear wheel 3RL and the right rear wheel 3RR may be prioritized over control for decreasing the braking force of the wheel 3RR. That is, during execution of the braking force distribution control, the ECU 8 determines the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR when it is requested to apply a left / right braking force difference at a change speed larger than the change speed upper limit value.
- the pressure reduction is limited and the braking force is not reduced (the braking force reduction is stopped), while the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR is preferentially allowed and the braking force is preferentially increased. .
- the ECU 8 prohibits the braking force reduction request itself at the time of the braking force reduction request for either the left rear wheel 3RL or the right rear wheel 3RR, and does not output the braking force reduction request, or the braking force request value Does not decrease.
- the ECU 8 allows the braking force increase request when the braking force increase request is made for either the left rear wheel 3RL or the right rear wheel 3RR, and increases the braking force request value as usual. As a result, the ECU 8 can restrict the braking force distribution control so that the left / right braking force difference change speed does not increase any more, and the braking force difference can fall within an allowable range.
- the ECU 8 determines in ST107 and ST112 that the current left / right braking force difference change speed of the left rear wheel 3RL and the right rear wheel 3RR is larger than the threshold value D1, the following control is performed. Then, priority is given to increasing the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR, and the pressure reduction of the brake hydraulic pressure is limited. Thus, the ECU 8 adjusts the braking force by adjusting the brake hydraulic pressure of the left rear wheel 3RL and the right rear wheel 3RR while keeping the left / right braking force difference changing speed within the change speed upper limit value.
- the ECU 8 controls the hydraulic control device 10 to increase the brake hydraulic pressure of the control target rear wheel (ST110). ).
- the ECU 8 has a brake hydraulic pressure that is not the main control target rear wheel.
- the pressure reduction and the reduction of the braking force are limited, and priority is given to the increase of the brake hydraulic pressure and the increase of the braking force of the rear wheel to be controlled.
- the ECU 8 suppresses the left / right braking force difference change speed from becoming greater than or equal to the change speed upper limit value.
- the ECU 8 determines in ST109 that the control target rear wheel is an outer wheel (ST109: Yes), regardless of the state of the left rear wheel 3RL and the right rear wheel 3RR that is not the control target rear wheel,
- the hydraulic control device 10 is controlled to increase the brake hydraulic pressure of both rear wheels (left rear wheel 3RL, right rear wheel 3RR) and simultaneously increase the braking force of both rear wheels (ST111A), and the current control cycle is completed. Then, the next control cycle is started.
- the ECU 8 can minimize the occurrence of disturbance in the behavior of the vehicle 2 while suppressing the left / right braking force difference change speed from exceeding the change speed upper limit value. .
- the ECU 8 controls the hydraulic control device 10 to reduce the brake hydraulic pressure of the control target rear wheel (ST115).
- ST115 the brake hydraulic pressure increase request for one of the left rear wheel 3RL and the right rear wheel 3RR that is not the main control target rear wheel
- the ECU 8 brakes the brake that is not the main control target rear wheel.
- Priority is given to the increase in hydraulic pressure and the increase in braking force, and the pressure reduction and the reduction in braking force of the rear wheel to be controlled are restricted.
- the ECU 8 suppresses the left / right braking force difference change speed from becoming greater than or equal to the change speed upper limit value.
- the ECU 8 determines in ST114 that the controlled rear wheel is an inner wheel (ST114: Yes), regardless of the state of the left rear wheel 3RL and the right rear wheel 3RR that is not the controlled rear wheel, Brake hydraulic pressure reduction and braking force reduction are prohibited, the hydraulic control device 10 is controlled to maintain the brake hydraulic pressure of the rear wheel to be controlled and the braking force of the rear wheel to be controlled (ST116A). End the cycle and move to the next control cycle. As a result, the ECU 8 can minimize the occurrence of disturbance in the behavior of the vehicle 2 while suppressing the left / right braking force difference change speed from exceeding the change speed upper limit value. .
- the braking force control apparatus 1001 can set the left rear wheel 3RL and the right rear wheel 3RR to an appropriate slip ratio while keeping the left / right braking force difference change speed within an allowable range. For example, when the rear load is large, etc. In addition, the deceleration can be increased and the directional stability of the vehicle 2 can be reliably ensured.
- FIG. 4 is a diagram showing an example of a change speed upper limit value map of the braking force control apparatus according to the second embodiment.
- the braking force control apparatus according to the second embodiment is different from the first embodiment in that the change speed upper limit value is changed according to the deceleration of the vehicle.
- the overlapping description is abbreviate
- FIG. 1 For details of each configuration of the braking force control apparatus according to the second embodiment, refer to FIG. 1 as appropriate (the same applies to the following embodiments).
- the ECU 8 of the braking force control device 1201 changes the change speed upper limit value according to the deceleration of the vehicle 2.
- the change speed upper limit value set for the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR is set so as to decrease as the deceleration of the vehicle 2 increases.
- the degree of deceleration of the vehicle 2 increases as the deceleration of the vehicle 2 becomes a relatively large value on the positive (+) side.
- the change speed upper limit value map m101 illustrated in FIG. 4 is a map for setting the change speed upper limit value (threshold value D1), and the horizontal axis indicates the deceleration generated in the vehicle 2 (hereinafter referred to as “generated deceleration”). "), The vertical axis indicates the upper limit of the change rate.
- This change speed upper limit map m101 describes the relationship between the generated deceleration and the change speed upper limit.
- the change speed upper limit value map m101 is stored in the storage unit of the ECU 8 after the relationship between the generated deceleration and the change speed upper limit value is set in advance based on actual vehicle evaluation and the like.
- the change speed upper limit value decreases as the generated deceleration increases.
- the ECU 8 calculates the change speed upper limit value of the left / right braking force difference change speed from the generated deceleration (for example, an absolute value) detected by the longitudinal acceleration sensor 14 or the like based on the change speed upper limit map m101. Thereby, ECU8 can make small change speed upper limit of the right-and-left braking force difference, so that deceleration of vehicles 2 is large.
- the ECU 8 has been described as calculating the change speed upper limit value using the change speed upper limit value map m101 illustrated in FIG. 4, but the present embodiment is not limited to this.
- the ECU 8 may calculate the change speed upper limit value based on a mathematical model corresponding to the change speed upper limit map illustrated in FIG. 4. The same applies to various maps described below.
- the vehicle 2 tends to have higher behavioral sensitivity as the generated deceleration increases.
- the braking force control device 1201 configured as described above sets the change speed upper limit value to a smaller value as the generated deceleration increases, so that the vehicle 2 that changes according to the generated deceleration is set.
- the stability of the vehicle 2 can be ensured appropriately corresponding to the behavior sensitivity.
- the braking force control device 1201 is relatively high in the high deceleration region where a relatively large left / right braking force difference is required for directional stability, because no upper limit is set for the left / right braking force difference itself. Therefore, a large left-right braking force difference can be allowed, and the left-right braking force difference change speed can be suppressed.
- the braking force control device 1201 can stabilize the behavior of the vehicle 2 more reliably by the braking force distribution control.
- FIG. 5 is a diagram illustrating an example of a change speed upper limit value map of the braking force control apparatus according to the third embodiment.
- the braking force control apparatus according to the third embodiment differs from the first and second embodiments in that the change speed upper limit value is changed according to the change speed of the deceleration of the vehicle.
- the ECU 8 of the braking force control apparatus 1301 changes the change speed upper limit value according to the change speed of the deceleration of the vehicle 2.
- the rate of change in deceleration of the vehicle 2 corresponds to the amount of change in deceleration per unit time.
- the change speed upper limit value set for the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR is set so as to increase as the deceleration change speed of the vehicle 2 increases.
- the change speed upper limit value map m102 illustrated in FIG. 5 is a map for setting the change speed upper limit value (threshold value D1), and the horizontal axis represents the change speed of the generated deceleration generated in the vehicle 2, the vertical axis. Indicates the upper limit of change speed.
- This change speed upper limit value map m102 describes the relationship between the generated deceleration change speed and the change speed upper limit value.
- the change speed upper limit value map m102 is stored in the storage unit of the ECU 8 after the relationship between the generated deceleration change speed and the change speed upper limit value is set in advance based on actual vehicle evaluation and the like. In this change speed upper limit value map m102, the change speed upper limit value increases as the generated deceleration change speed increases.
- the ECU 8 calculates the change speed upper limit value of the left / right braking force difference change speed from the change speed of the generated deceleration (for example, absolute value) detected by the longitudinal acceleration sensor 14 or the like.
- the ECU 8 can increase the change speed upper limit value of the left-right braking force difference as the deceleration change speed of the vehicle 2 is larger.
- the braking force control device 1301 configured as described above sets the change speed upper limit value to a larger value as the generated deceleration change speed increases, that is, as the braking becomes sudden. As a result, the braking force control device 1301 can apply the left-right braking force difference at a relatively large change speed during sudden braking. As a result, the braking force control device 1301 can make a relatively large difference between the left and right braking force by braking force distribution control even during sudden braking, so that the behavior of the vehicle 2 can be ensured even during sudden braking. Can be stabilized.
- FIG. 6 is a diagram illustrating an example of a change speed upper limit value map of the braking force control apparatus according to the fourth embodiment.
- the braking force control apparatus according to the fourth embodiment differs from the first to third embodiments in that the change speed upper limit value is changed according to the traveling speed of the vehicle.
- the ECU 8 of the braking force control apparatus 1401 changes the change speed upper limit value according to the vehicle speed that is the traveling speed of the vehicle 2.
- the change speed upper limit value set for the left / right braking force difference between the left rear wheel 3RL and the right rear wheel 3RR is set to be smaller as the vehicle speed of the vehicle 2 is higher.
- the change speed upper limit value map m103 illustrated in FIG. 6 is a map for setting the change speed upper limit value (threshold value D1).
- the horizontal axis indicates the vehicle speed of the vehicle 2, and the vertical axis indicates the change speed upper limit value. .
- the change speed upper limit value map m103 describes the relationship between the vehicle speed and the change speed upper limit value of the difference between the left and right braking forces.
- the change speed upper limit value map m103 is stored in the storage unit of the ECU 8 after the relationship between the vehicle speed and the change speed upper limit value is set in advance based on actual vehicle evaluation and the like. In the change speed upper limit value map m103, the change speed upper limit value of the left / right braking force difference decreases as the vehicle speed increases.
- the ECU 8 calculates the change speed upper limit value of the left / right braking force difference change speed from the vehicle speed estimated from the wheel speed detected by each wheel speed sensor 13. Thereby, ECU8 can make small change speed upper limit of the right-and-left braking force difference, so that the vehicle speed of vehicles 2 is high.
- the behavior sensitivity of the vehicle 2 due to a difference in tire characteristics between the left and right wheels 3 and an unintended left / right braking force difference caused by ⁇ split road traveling increases as the vehicle speed increases relatively. There is a tendency. For this reason, the behavior of the vehicle 2 tends to increase as the vehicle speed becomes relatively higher even at the same left / right braking force difference change speed.
- the braking force control device 1401 configured as described above sets the change speed upper limit value of the left / right braking force difference change speed to a smaller value as the vehicle speed increases.
- the braking force control device 1401 can suppress the right / left braking force difference change speed allowed in the braking force distribution control as the behavior sensitivity of the vehicle 2 becomes relatively high, and the behavior sensitivity of the vehicle 2 becomes relatively high.
- the lower left and right braking force difference change speed can be increased as the value decreases. Therefore, the braking force control device 1401 substantially changes the behavior of the vehicle 2 due to an unintended braking force difference from a high-speed driving region where the behavior sensitivity of the vehicle 2 is relatively high to a low-speed driving region where the behavior sensitivity is relatively low. It can suppress equally and, thereby, driving
- FIG. 7 is a diagram illustrating an example of a change speed upper limit value map of the braking force control apparatus according to the fifth embodiment.
- the braking force control apparatus according to Embodiment 5 differs from Embodiments 1 to 4 in that the change speed upper limit value is changed according to the change speed of the lateral movement of the vehicle.
- the ECU 8 of the braking force control apparatus 1501 changes the change speed upper limit value according to the change speed of the lateral movement of the vehicle 2.
- the change speed upper limit value set for the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR is set to increase as the lateral movement change speed of the vehicle 2 increases.
- the index indicating the magnitude of the lateral movement of the vehicle 2 is detected by the yaw rate of the vehicle 2 detected by the yaw rate sensor 15, the lateral acceleration of the vehicle 2 detected by the lateral acceleration sensor 16, and the steering angle sensor 17, for example.
- the rudder angle of the vehicle 2 can be used.
- the index representing the change speed of the lateral movement of the vehicle 2 corresponds to the yaw rate per unit time, the lateral acceleration, or the change amount of the steering angle.
- the change speed upper limit value map m104 illustrated in FIG. 7 is a map for setting the change speed upper limit value (threshold value D1).
- the horizontal axis represents the change speed of the lateral motion of the vehicle 2 (yaw rate change speed (dYr ), Lateral acceleration change speed (dGy) or rudder angle change speed (d rudder angle)), and the vertical axis represents the change speed upper limit value set for the left and right braking force difference change speed.
- This change speed upper limit value map m104 describes the relationship between the index representing the change speed of the lateral movement and the change speed upper limit value.
- the change speed upper limit value map m104 is stored in the storage unit of the ECU 8 after the relationship between the index representing the change speed of the lateral motion and the change speed upper limit value is set in advance based on the actual vehicle evaluation and the like.
- the change speed upper limit value map m104 the change speed upper limit value increases as the index representing the change speed of the lateral motion increases.
- the ECU 8 determines the yaw rate of the vehicle 2 detected by the yaw rate sensor 15, the lateral acceleration of the vehicle 2 detected by the lateral acceleration sensor 16, or the vehicle 2 detected by the steering angle sensor 17 based on the change speed upper limit value map m104.
- the change speed upper limit value of the left / right braking force difference change speed is calculated from the steering angle. Thereby, the ECU 8 can increase the change speed upper limit value of the left / right braking force difference change speed as the change speed of the lateral movement of the vehicle 2 is larger.
- the braking force control device 1501 provides a change speed upper limit value for the left and right braking force difference change speed in the braking force distribution control, so that the vehicle can be applied during turning braking that requires a quicker left and right braking force difference than when traveling straight. Stability may be suppressed.
- the braking force control device 1501 configured as described above, for example, when the vehicle 2 is moving laterally, the lateral braking force difference change rate increases as the lateral motion change rate of the vehicle 2 increases. Set the upper limit of change speed to a larger value. As a result, the braking force control device 1501 sets the upper limit value of the left / right braking force difference change speed to a larger value than when the vehicle 2 is traveling straight when the change speed of the lateral movement of the vehicle 2 is relatively large. The left-right braking force difference can be quickly applied in response to fast behavior changes that occur at times.
- the braking force control device 1501 can quickly apply the left-right braking force difference while allowing the necessary left-right braking force difference change speed in accordance with the behavior change of the vehicle 2 during turning braking, etc. It is possible to minimize the occurrence of disturbance in the behavior of the vehicle 2 due to an unintended left-right braking force difference.
- FIGS. 8 and 9 are schematic diagrams for explaining the change speed upper limit value of the braking force control apparatus according to the sixth embodiment.
- the braking force control apparatus according to the sixth embodiment differs from the first to fifth embodiments in the method of setting the change speed upper limit value.
- the ECU 8 of the braking force control device 1601 (see FIG. 1) according to the present embodiment responds to the magnitude relationship of the braking force between the left rear wheel 3RL and the right rear wheel 3RR based on the detection result of the wheel cylinder pressure sensor 19 and the like. To set the change speed upper limit of the left / right braking force difference change speed.
- the ECU 8 moves the vehicle 2 in the direction of the lateral movement of the left rear wheel 3RL and the right rear wheel 3RR (the left rear wheel 3RL in the example of FIG. 8) having the larger braking force.
- the change speed upper limit value of the left / right braking force difference change speed is set so as to be relatively small when the wheels are on the same direction side.
- the vehicle 2 tends to promote lateral movement when the wheel with the larger braking force among the left rear wheel 3RL and the right rear wheel 3RR is the wheel in the same direction as the direction of lateral movement.
- the ECU 8 further describes the movement of the vehicle 2 due to the lateral braking force difference change speed. Is a direction to increase the lateral movement of the vehicle 2, the change speed upper limit value can be relatively reduced.
- the ECU 8 is configured such that the wheel on the side with the larger braking force among the left rear wheel 3RL and the right rear wheel 3RR (the left rear wheel 3RL in the example of FIG.
- the change speed upper limit value of the left / right braking force difference change speed is set to be relatively large.
- the vehicle 2 tends to cancel the lateral movement when the wheel having the larger braking force among the left rear wheel 3RL and the right rear wheel 3RR is the wheel on the opposite side to the direction of the lateral movement.
- the ECU 8 when the magnitude relationship of the braking force between the left rear wheel 3RL and the right rear wheel 3RR is a relationship that cancels the lateral movement of the vehicle 2, the ECU 8 further states that the movement of the vehicle 2 due to the lateral braking force difference change speed is When the direction is to cancel the lateral movement of the vehicle 2, the change speed upper limit value of the left / right braking force difference change speed can be relatively increased.
- the braking force control device 1601 configured as described above, for example, when the vehicle 2 is steered after the start of braking, the vehicle 2 caused by the lateral movement direction of the vehicle 2 by the steering and the left and right braking force difference.
- the change speed upper limit value of the left / right braking force difference change speed can be set according to the relationship with the behavior change direction.
- the braking force control device 1601 can sufficiently tolerate the left / right braking force difference change speed for the side on which the behavior of the vehicle 2 is stabilized, and can quickly apply the left / right braking force difference.
- the braking force control device 1601 can reliably suppress the left / right braking force difference change speed on the side where the behavior of the vehicle 2 becomes unstable, and can suppress the application of the left / right braking force difference. As a result, the braking force control device 1601 can more reliably perform the braking force distribution control even when there is a large change in the behavior of the vehicle 2 after the start of braking, for example, when the vehicle 2 is steered after the start of braking. In addition, the behavior of the vehicle 2 can be stabilized.
- FIG. 10 is a diagram illustrating an example of a change speed upper limit value map of the braking force control apparatus according to the seventh embodiment.
- the braking force control apparatus according to the seventh embodiment differs from the first to sixth embodiments in that the change speed upper limit value is changed according to the deviation of the wheel speeds of the left and right wheels of the front wheel of the vehicle.
- the wheels 3 of the vehicle 2 to be controlled by the braking force distribution control of the braking force control device 1701 are the left and right wheels 3 of the rear wheels of the vehicle 2, that is, the left Rear wheel 3RL and right rear wheel 3RR.
- the ECU 8 may be referred to as a wheel speed difference between the left and right wheels 3 of the front wheel of the vehicle 2, that is, the left front wheel 3FL and the right front wheel 3FR, here, a wheel speed difference (hereinafter referred to as “front wheel speed difference”). )
- front wheel speed difference To change the change speed upper limit value of the left / right braking force difference change speed.
- the change speed upper limit value set for the left and right braking force difference change speeds of the left rear wheel 3RL and the right rear wheel 3RR is the front wheel wheel speed difference or the change speed of the front wheel wheel speed difference (hereinafter, It may be referred to as “front wheel speed difference change speed.”) Is set to increase as the value increases.
- the change speed upper limit value map m105 illustrated in FIG. 10 is a map for setting the change speed upper limit value (threshold value D1), and the horizontal axis represents the front wheel wheel speed difference or the front wheel wheel speed difference change speed, and the vertical axis represents The change speed upper limit value set for the left / right braking force difference change speed is shown.
- This change speed upper limit value map m105 describes the relationship between the front wheel speed difference or the change between the front wheel speed difference change speed and the change speed upper limit value.
- the change speed upper limit value map m105 is stored in the storage unit of the ECU 8 after the front wheel speed difference or the relationship between the front wheel speed difference change speed and the change speed upper limit value is set in advance based on actual vehicle evaluation and the like. Has been.
- the change speed upper limit value increases as the front wheel speed difference or the front wheel speed difference change speed increases.
- the ECU 8 calculates the change speed upper limit value of the left / right braking force difference change speed from the wheel speeds detected by the wheel speed sensors 13 of the left front wheel 3FL and the right front wheel 3FR.
- the ECU 8 can increase the change speed upper limit value of the left / right braking force difference change speed as the front wheel speed difference or the front wheel speed difference change speed increases.
- the vehicle 2 has a front wheel speed difference or a front wheel when a difference in ground load between the left and right wheels 3 is relatively large, or when a change in behavior of the vehicle 2 such as a sudden deflection of the vehicle body appears.
- the wheel speed difference change speed tends to be relatively large.
- the braking force control device 1701 configured as described above, for example, increases the change speed upper limit value of the left and right braking force difference change speed as the front wheel speed difference or the front wheel speed difference change speed increases. Set to a large value.
- the braking force control device 1701 allows a relatively large left / right braking force difference change rate when the difference in ground load between the left and right wheels 3 is relatively large or when the behavior change of the vehicle 2 appears greatly. It is possible to quickly apply the left / right braking force difference as necessary.
- the braking force control device 1701 allows the left and right braking force difference changing speed to be quickly changed while allowing the right and left braking force difference change speed when the difference in ground load between the left and right wheels 3 is relatively large or when the behavior change of the vehicle 2 appears greatly. While it is possible to apply a braking force difference, it is possible to minimize the occurrence of disturbance in the behavior of the vehicle 2 due to an unintended left / right braking force difference when it is not necessary.
- the braking force control device according to the above-described embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the claims.
- the braking force control apparatus according to the present embodiment may be configured by appropriately combining the components of the embodiments described above.
- control device of the braking force control device has been described as an ECU that controls each part of the vehicle.
- control device is not limited thereto, and is configured separately from the ECU, for example, and is detected mutually with the ECU. It may be configured to exchange information such as signals, drive signals, and control commands.
- control device has been described as using the difference between the braking forces of the left and right wheels as the left and right braking force deviation.
- the present invention is not limited to this, and for example, the ratio of the braking forces of the left and right wheels (for example, (Braking force / braking force of the other wheel) or the like may be used.
- Braking force control device 2 Vehicle 3 Wheel 3RR Right rear wheel 3FR Right front wheel 3RL Left rear wheel 3FL Left front wheel 7 Braking device 8 ECU (control device)
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Abstract
Description
図1は、実施形態1に係る制動力制御装置が適用された車両の概略構成図、図2は、実施形態1に係る制動力制御装置のECUによる制動力配分制御の一例を説明するフローチャート、図3は、変形例に係る制動力制御装置のECUによる制動力配分制御の一例を説明するフローチャートである。
κ=(Vr-Vw)/Vr ・・・ (1)
図4は、実施形態2に係る制動力制御装置の変化速度上限値マップの一例を示す線図である。実施形態2に係る制動力制御装置は、変化速度上限値が車両の減速度に応じて変更される点で実施形態1とは異なる。その他、上述した実施形態と共通する構成、作用、効果については、重複した説明はできるだけ省略する。なお、実施形態2に係る制動力制御装置の各構成の詳細については、適宜、図1を参照する(以下の実施形態でも同様である。)。
図5は、実施形態3に係る制動力制御装置の変化速度上限値マップの一例を示す線図である。実施形態3に係る制動力制御装置は、変化速度上限値が車両の減速度の変化速度に応じて変更される点で実施形態1、2とは異なる。
図6は、実施形態4に係る制動力制御装置の変化速度上限値マップの一例を示す線図である。実施形態4に係る制動力制御装置は、変化速度上限値が車両の走行速度に応じて変更される点で実施形態1~3とは異なる。
図7は、実施形態5に係る制動力制御装置の変化速度上限値マップの一例を示す線図である。実施形態5に係る制動力制御装置は、変化速度上限値が車両の横運動の変化速度に応じて変更される点で実施形態1~4とは異なる。
図8、図9は、実施形態6に係る制動力制御装置の変化速度上限値について説明するための模式図である。実施形態6に係る制動力制御装置は、変化速度上限値の設定手法が実施形態1~5とは異なる。
図10は、実施形態7に係る制動力制御装置の変化速度上限値マップの一例を示す線図である。実施形態7に係る制動力制御装置は、変化速度上限値が車両の前輪の左右の車輪の車輪速度の偏差に応じて変更される点で実施形態1~6とは異なる。
2 車両
3 車輪
3RR 右後輪
3FR 右前輪
3RL 左後輪
3FL 左前輪
7 制動装置
8 ECU(制御装置)
Claims (10)
- 車両の各車輪に生じる制動力を個別に調節可能である制動装置と、
前記制動装置を制御し前記車両の左右の車輪のスリップ状態が同等となるように当該左右の車輪の制動力を個別に制御する制動力配分制御を実行可能である制御装置とを備え、
前記制御装置は、前記左右の車輪の制動力の偏差である左右制動力偏差の変化速度の変化速度上限値に基づいて、前記制動力配分制御を実行することを特徴とする、
制動力制御装置。 - 前記制御装置は、前記制動力配分制御において、前記左右制動力偏差の変化速度が前記変化速度上限値より大きい場合、前記左右の車輪の前記制動力を増加させる制御より当該左右の車輪の前記制動力を低減させる制御を優先させる、
請求項1に記載の制動力制御装置。 - 前記制御装置は、前記制動力配分制御において、前記左右制動力偏差の変化速度が前記変化速度上限値より大きい場合、前記左右の車輪の前記制動力を低減させる制御より当該左右の車輪の前記制動力を増加させる制御を優先させる、
請求項1に記載の制動力制御装置。 - 前記変化速度上限値は、前記車両の減速度が大きいほど小さい、
請求項1乃至請求項3のいずれか1項に記載の制動力制御装置。 - 前記変化速度上限値は、前記車両の減速度の変化速度が大きいほど大きい、
請求項1乃至請求項4のいずれか1項に記載の制動力制御装置。 - 前記変化速度上限値は、前記車両の走行速度が高いほど小さい、
請求項1乃至請求項5のいずれか1項に記載の制動力制御装置。 - 前記変化速度上限値は、前記車両の横運動の変化速度が大きいほど大きい、
請求項1乃至請求項6のいずれか1項に記載の制動力制御装置。 - 前記変化速度上限値は、前記左右の車輪のうち制動力が大きい側の車輪が前記車両の横運動の向きと同方向側の車輪である場合に相対的に小さく、前記左右の車輪のうち制動力が大きい側の車輪が前記車両の横運動の向きと反対方向側の車輪である場合に相対的に大きい、
請求項1乃至請求項7のいずれか1項に記載の制動力制御装置。 - 前記変化速度上限値は、前記左右制動力偏差の変化速度による前記車両の運動が当該車両の横運動を打ち消す向きである場合に相対的に大きく、前記左右制動力偏差の変化速度による前記車両の運動が当該車両の横運動を大きくする向きである場合に相対的に小さい、
請求項1乃至請求項8のいずれか1項に記載の制動力制御装置。 - 前記制動力配分制御による制御対象の前記車両の車輪は、当該車両の後輪の前記左右の車輪であり、
前記変化速度上限値は、前記車両の前輪の前記左右の車輪の車輪速度の偏差、又は、当該車輪速度の偏差の変化速度が大きいほど大きい、
請求項1乃至請求項9のいずれか1項に記載の制動力制御装置。
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DE112013001485.8T DE112013001485T5 (de) | 2012-03-16 | 2013-01-17 | Bremskraft-Regelungsvorrichtung |
US14/385,359 US20150073678A1 (en) | 2012-03-16 | 2013-01-17 | Braking force control device |
CN201380013677.2A CN104169140A (zh) | 2012-03-16 | 2013-01-17 | 制动力控制装置 |
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EP2905189B1 (en) * | 2012-10-05 | 2017-04-05 | Toyota Jidosha Kabushiki Kaisha | Vehicle brake control device |
CN104925044B (zh) * | 2015-05-15 | 2017-10-27 | 华南农业大学 | 一种山地果园运输机动力主动控制系统 |
CN106379299B (zh) * | 2015-08-04 | 2019-06-11 | 北京宝沃汽车有限公司 | 一种车辆制动跑偏控制方法、系统及汽车 |
JP6790971B2 (ja) * | 2017-04-03 | 2020-11-25 | トヨタ自動車株式会社 | 車両のブレーキ装置 |
CN109910850B (zh) * | 2017-12-13 | 2020-06-19 | 比亚迪股份有限公司 | 车辆及其制动控制方法和装置 |
CN111098838A (zh) * | 2018-10-26 | 2020-05-05 | 北汽福田汽车股份有限公司 | 车辆控制方法、装置及车辆 |
CN110040124B (zh) * | 2019-04-24 | 2020-04-17 | 中通客车控股股份有限公司 | 一种车辆紧急制动控制方法及系统 |
MX2023004460A (es) * | 2020-10-20 | 2023-04-28 | Nissan Motor | Metodo de control de fuerza motriz y dispositivo de control de fuerza motriz. |
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JPH1159364A (ja) * | 1997-08-21 | 1999-03-02 | Nissan Motor Co Ltd | 車輪スリップ制御装置付き車両の挙動制御装置 |
JP2007055583A (ja) * | 2005-07-28 | 2007-03-08 | Nissin Kogyo Co Ltd | 車両用ブレーキ圧制御装置 |
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JPS6032220A (ja) * | 1983-08-03 | 1985-02-19 | 株式会社日立製作所 | 故障表示器 |
JP2704771B2 (ja) * | 1989-10-18 | 1998-01-26 | 本田技研工業株式会社 | 車両のトラクション制御方法 |
EP0985586B1 (de) * | 1998-09-07 | 2009-02-25 | Pacifica Group Technologies Pty Ltd | Antiblockiersystem auf der Basis eines Fuzzy-Reglers für ein elektromechanisches Fahrzeug-Bremssystem |
JP5431745B2 (ja) * | 2009-02-13 | 2014-03-05 | マツダ株式会社 | 車両の運動制御装置 |
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JP5494814B2 (ja) * | 2010-09-29 | 2014-05-21 | トヨタ自動車株式会社 | 車両の制御装置 |
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- 2013-01-17 DE DE112013001485.8T patent/DE112013001485T5/de not_active Withdrawn
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JPH0632220A (ja) * | 1992-07-17 | 1994-02-08 | Naldec Kk | 車両のアンチスキッドブレーキ装置 |
JPH1159364A (ja) * | 1997-08-21 | 1999-03-02 | Nissan Motor Co Ltd | 車輪スリップ制御装置付き車両の挙動制御装置 |
JP2007055583A (ja) * | 2005-07-28 | 2007-03-08 | Nissin Kogyo Co Ltd | 車両用ブレーキ圧制御装置 |
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JP5472350B2 (ja) | 2014-04-16 |
DE112013001485T5 (de) | 2014-11-27 |
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