JP2013123972A - Vehicle braking force control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure responsiveness required in pressing on a brake pedal again in a slope-road stopping scene, and suppress noises leading to the degradation of sound vibration performance in the other flat-road stopping scenes.SOLUTION: This vehicle braking force control device includes a brake controller for computing target hydraulic pressure braking force on the basis of a pedal stroke amount sensor value from a pedal stroke sensor, an electric booster by which assist force is controlled on the basis of the target hydraulic pressure braking force, and a master cylinder using piston thrust obtained by adding the assist force to pedal pressure for generating master cylinder pressure. The brake controller determines the state of a vehicle on the basis of a detection value from a vehicle state detecting part 63 (a vehicle state determining part 64), and performs noise removing control to remove noises overlapping the pedal stroke amount sensor value at a higher degree when determining that the vehicle is on a flat road and stopping thereon than when determining that it is on a slope road and stopping thereon (a controller selecting part 65).

Description

  The present invention relates to a vehicular braking force control device including a booster in which an assist force is controlled based on a target hydraulic braking force calculated based on a sensor detection value from a brake operation sensor.

Conventionally, when the brake is operated, the assist force of the pedal depression force is obtained by the electric booster, and the input rod input (Fi) corresponding to the pedal depression force is
Input rod input (Fi) = master cylinder pressure (Pb) x input rod area (Ai) + spring constant of spring 85 (K) x ΔX
An electric booster given by the following equation is known (see, for example, Patent Document 1).

JP 2007-112426 A

However, the conventional electric booster is configured to determine the target displacement based on the sensor input, push the piston to the target position with the motor torque, and increase the master cylinder pressure. It was.
1. When noise is superimposed on the sensor, the calculated target displacement is also affected by the noise and the motor (and unit) vibrates. In particular, when the vehicle is stopped, the background vibration and background noise are small, and the motor vibration is the source of vibration, causing slight fluctuations in the brake pedal (pedal vibration) and sound transmitted to the vehicle interior (vehicle interior noise), which makes the driver uncomfortable. give.
2. If filters and dead zones are always actively introduced to suppress noise effects, control responsiveness and stability will be impaired. That is, at the time of brake operation during traveling (not stopping), generation of the master cylinder pressure is delayed and the stopping distance is extended.

  Here, “dark vibration / dark noise” refers to vibration / noise at a specific location when there is no target vibration / sound when the specific vibration / sound is considered as a target. In other words, when the vehicle is stopped with low background vibration and background noise, it is a situation in which the driver and other passengers in the passenger compartment are highly sensitive to vibration and sound.

  The present invention has been made paying attention to the above-mentioned problem, ensuring the responsiveness required when the brakes are stepped on again on a ramp stop scene, and noise causing a decrease in sound vibration performance on other flat road stop scenes. An object of the present invention is to provide a vehicular braking force control device that can be suppressed.

In order to achieve the above object, a braking force control device for a vehicle according to the present invention includes a brake controller that calculates a target hydraulic braking force based on a sensor detection value from a brake operation sensor that detects a brake operation by a driver, and the target fluid A booster in which the assist force is controlled based on the pressure braking force; and a master cylinder that generates a master cylinder pressure by a piston thrust obtained by adding the assist force to the pedal depression force.
In this vehicle braking force control apparatus, vehicle state detection means for detecting the vehicle state is provided.
The brake controller determines a vehicle state based on a detection value from the vehicle state detection means, and determines that the brake operation sensor has a flat road and a stop when compared with a case where it is determined that the road is a ramp and stopped. Noise removal control is performed to increase the degree of removal of noise superimposed on the sensor detection value.

Therefore, in the slope stop scene, the degree of removing noise superimposed on the sensor detection value of the brake operation sensor is reduced. That is, the ramp stop scene such as uphill or downhill is a scene in which the vehicle is likely to start when the brake pedal is returned to the release direction. In this case, when the brake is stepped on again due to vehicle slipping or the like, the brake response is required. However, the brake response is ensured by reducing the noise removal degree.
On the other hand, in a flat road stop scene, the degree of removing noise superimposed on the sensor detection value of the brake operation sensor is increased. That is, in a flat road stop scene, the vehicle does not start even when the brake pedal is returned to the release direction, so that brake response is not required, and noise suppression is more important than ensuring brake response. On the other hand, by increasing the noise removal degree, noise that causes a decrease in sound vibration performance can be suppressed.
As a result, it is possible to ensure the responsiveness required when the brake is stepped on again on a ramp stop scene, and to suppress noise that causes a decrease in sound vibration performance on other flat stop scenes.

1 is an overall system diagram illustrating an overall configuration of a vehicle braking force control apparatus according to a first embodiment. It is a control block diagram which shows the noise removal control structure of the brake controller in the braking force control apparatus for vehicles of Example 1. FIG. It is a flowchart which shows the flow of the control intervention determination process performed in the control intervention determination part of the noise removal control structure in the braking force control apparatus for vehicles of Example 1. FIG. 3 is a flowchart illustrating a flow of control release determination processing executed by a control release determination unit of the noise removal control configuration in the vehicle braking force control apparatus according to the first embodiment. It is explanatory drawing which shows the generation | occurrence | production mechanism of the pedal vibration and vehicle interior noise in the braking force control apparatus for vehicles of a comparative example. FIG. 5 is an operation explanatory diagram showing an operation flow until a master cylinder pressure is generated based on a brake pedal operation in the vehicle braking force control apparatus of the first embodiment.

  Hereinafter, the best mode for realizing a vehicle braking force control apparatus according to the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
The configuration of the vehicular braking force control apparatus according to the first embodiment will be described by dividing it into “entire system configuration”, “noise removal control configuration”, “control intervention determination processing configuration”, and “control release determination processing configuration”.

[Overall system configuration]
FIG. 1 is an overall system diagram illustrating an overall configuration of a vehicle braking force control apparatus according to a first embodiment. The overall system configuration will be described below with reference to FIG. The vehicle braking force control apparatus according to the first embodiment is applied to an electric vehicle such as an electric vehicle or a hybrid vehicle.

  As shown in FIG. 1, the vehicle braking force control apparatus according to the first embodiment includes a brake pedal 1, an electric booster 2 (booster), a master cylinder 3, a brake hydraulic pressure actuator 4, wheel cylinders 5FL, 5FR, 5RL, 5RR, a brake controller 6, and a motor drive circuit 7 are provided.

  The brake pedal 1 applies a driver's pedal effort when braking. The upper end portion of the brake pedal 1 is supported so as to be rotatable with respect to the vehicle body, and the middle portion of the brake pedal 1 is connected to the input rod 9 via a clevis pin 8.

  The electric booster 2 assists the pedal effort with the thrust of the electric motor 10. The electric booster 2 converts the motor torque generated by the electric motor 10 into a piston thrust via a ball screw, and causes the piston thrust to act on the primary piston 11. The electric booster 2 is fixed to the dash panel 12 together with the master cylinder 3.

  The master cylinder 3 is a master cylinder pressure (primary pressure, which is guided to the wheel cylinders 5FL, 5FR, 5RL, and 5RR provided in each wheel by a piston thrust obtained by adding an assist force by the electric motor 10 to the pedal depression force during a brake operation. Secondary pressure) is generated. The master cylinder 3 has a primary piston 11 that inputs pedal depression force applied to the input rod 9 via a pair of springs 13 and 13, and a secondary piston 14 that is integrally connected to the primary piston 11. The primary pressure created by the piston stroke of the primary piston 11 is guided to the brake hydraulic pressure actuator 4 through the primary pressure pipe 15. The secondary pressure created by the piston stroke of the secondary piston 14 is guided to the brake hydraulic pressure actuator 4 via the secondary pressure pipe 16.

  The brake hydraulic pressure actuator 4 guides the master cylinder pressure introduced through the primary pressure pipe 15 and the secondary pressure pipe 16 to the wheel cylinders 5FL, 5FR, 5RL, and 5RR as they are during normal braking operation. Note that during ABS control with brake operation, the hydraulic pressure obtained by reducing / holding / increasing the master cylinder pressure is guided to the wheel cylinders 5FL, 5FR, 5RL, and 5RR. Further, at the time of VDC control and TCS control not accompanied by a brake operation, the control hydraulic pressure based on the pump pressure by the electric pump is guided to a wheel cylinder that requires a braking force among the wheel cylinders 5FL, 5FR, 5RL, and 5RR.

  The wheel cylinders 5FL, 5FR, 5RL, 5RR are provided at the positions of the brake devices of the respective wheels, and apply braking force to the respective wheels in accordance with the wheel cylinder pressure guided through the wheel cylinder pressure pipes 17FL, 17FR, 17RL, 17RR. give.

  The brake controller 6 calculates a target hydraulic braking force (including a target value corresponding to a target hydraulic braking force such as a target deceleration) based on a pedal stroke amount sensor value from the pedal stroke sensor 18 during a brake operation. Then, a motor control current command is output to the motor drive circuit 7 (= motor current control unit) so that an assist force for achieving the target hydraulic braking force can be obtained. The brake controller 6 includes a pedal stroke sensor 18 (brake operation sensor), a master cylinder pressure sensor 19, a motor resolver 20, a brake switch 21, a wheel speed sensor 22, a front and rear G sensor 23, and a range position sensor. 24 and detection information from other sensors / switches 25 are input. The pedal stroke sensor 18, the master cylinder pressure sensor 19, the brake switch 21, the wheel speed sensor 22, the front / rear G sensor 23, and the range position sensor 24 correspond to vehicle state detection means.

  The pedal stroke sensor 18 uses a pedal stroke amount sensor value, which is a sensor detection value, as calculation input information of a target hydraulic braking force, and detects a brake operation amount (= pedal stroke amount) applied to the brake pedal 1 by a driver. . The pedal stroke sensor 18, the master cylinder pressure sensor 19, and the brake switch 21 are used as a brake pedal operation detection sensor (brake pedal operation detection means) that confirms operation information of the brake pedal 1 and determines operation of the brake pedal 1. .

  The wheel speed sensor 22 is used as a vehicle speed detection sensor (vehicle speed detection means) that checks vehicle speed information based on a vehicle speed sensor value and determines whether or not the vehicle is stopped.

  The front-rear G sensor 23 is used as a gradient detection sensor (gradient detection means) for confirming gradient information based on G sensor values and determining a flat road.

  The range position sensor 24 confirms a range signal indicating the selected range position, and determines whether it is a stopping range (P range or N range) or a driving range (D range, R range, 2-speed fixed range, etc.). Used as a drive detection sensor.

  The motor drive circuit 7 inputs the motor control current command from the brake controller 6 and the motor control current sensor value from the current sensor 26, and matches the power source current (DC) from the battery 27 with the motor control current command. It converts into motor control current (three-phase alternating current) to the electric motor 10.

[Noise reduction control configuration]
FIG. 2 is a control block diagram illustrating a noise removal control configuration of the brake controller 6 in the vehicle braking force control apparatus according to the first embodiment. Hereinafter, a noise removal control configuration that varies the degree of noise removal depending on the selection of the controller will be described with reference to FIG.

  As shown in FIG. 2, the brake controller 6 includes a control intervention determination unit 61 and a control release determination unit 62 as a noise removal control configuration. The control intervention determination unit 61 includes a vehicle state detection unit 63, a vehicle state determination unit 64, and a controller selection unit 65.

  The control intervention determination unit 61 determines the vehicle state in the vehicle state determination unit 64 based on the detection value from the vehicle state detection unit 63. When the controller selection unit 65 determines that the road is flat and the vehicle is stopped, the degree of removal of noise superimposed on the sensor detection value of the pedal stroke sensor 18 is larger than when the controller is determined to be a flat road and the vehicle is stopped. Perform noise removal control.

  The vehicle state detection unit 63 includes a brake pedal operation detection sensor 63a, a vehicle speed detection sensor 63b, a gradient detection sensor 63c, and a drive detection sensor 63d. As the brake pedal operation detection sensor 63a, a pedal stroke sensor 18 or the like is used. As the vehicle speed detection sensor 63b, the wheel speed sensor 22 or the like is used. As the gradient detection sensor 63c, the front-rear G sensor 23 or the like is used. The range position sensor 24 or the like is used as the drive detection sensor 63d.

  The vehicle state determination unit 64 includes a brake pedal operation determination unit 64a, a stop determination unit 64b, a slope determination unit 64c, and a range determination unit 64d. The brake pedal operation determination unit 64a determines the operation of the brake pedal 1 based on information from the brake pedal operation detection sensor 63a. The stop determination part 64b determines stop based on the information from the vehicle speed detection sensor 63b. The slope determination unit 64c determines a slope based on information from the gradient detection sensor 63c. The range determination unit 64d determines the range position of the automatic transmission based on information from the drive detection sensor 63d.

The controller selector 65 includes a controller selector 65a, a first controller 65b, a second controller 65c, and a third controller 65d. Based on the determination information from the vehicle state determination unit 64, the controller selection unit 65a selects one of the first controller 65b, the second controller 65c, the third controller 65d, and the normal controller 62b. select.
Here, the first controller 65b, the second controller 65c, and the third controller 65d are provided on the input side (pedal stroke amount sensor value, ball screw position sensor value) and output side (motor control current command) of the brake controller 6. On the other hand, a filter for reducing the gain of the peak frequency is implemented. The first controller 65b is equipped with a noise removal “large” filter. The second controller 65c implements a “medium” filter for noise removal. The third controller 65d is equipped with a noise removal “small” filter. The normal controller 62b, which is one of the controller options, is a controller without a filter.

  The control release determination unit 62 changes the degree of noise removal when the brake pedal operation is released, and includes a control release determination unit 62a and a normal controller 62b. Based on the operation information of the brake pedal 1 from the brake pedal operation detection sensor 63a, the control release determination unit 62a determines whether the brake pedal operation is being released or has been released. Based on the control release determination, the normal controller 62b does not perform the noise process to switch from the controller that performs the selected noise process among the first controller 65b, the second controller 65c, and the third controller 65d. It is a controller.

[Control intervention judgment processing configuration]
FIG. 3 is a flowchart illustrating the flow of the control intervention determination process executed by the control intervention determination unit 61 of the noise removal control configuration in the vehicle braking force control apparatus according to the first embodiment. Hereinafter, each step of FIG. 3 showing the control intervention determination processing configuration will be described.

  In step S1, following the start of processing or the noise processing not being performed in step S3 or step S6, the brake pedal operation detecting means (the pedal stroke sensor 18, the master cylinder pressure sensor 19, and the brake switch 21) is used to 1 operation information is confirmed, and the process proceeds to step S2.

In step S2, following the operation information confirmation of the brake pedal 1 in step S1, it is determined whether or not the brake pedal 1 is being depressed and the pedal is being held. If YES (while holding down the pedal), the process proceeds to step S4. If NO (except when holding down the pedal), the process proceeds to step S3.
Here, when the depression determination threshold value <the pedal stroke amount (depression condition) and the pedal stroke change amount <the retention determination threshold value (holding condition), it is determined that the pedal depression is being held. When at least one of the stepping condition and the holding condition is not satisfied, it is determined that the pedal is not being held.

  In step S3, following the determination in step S2 that the pedal is not being held down, the normal controller 62b is selected, noise processing is not performed, and the process returns to step S1.

  In step S4, following the determination that pedal depression is being held in step S2, vehicle speed information is confirmed using vehicle speed detection means (wheel speed sensor 22), and the process proceeds to step S5.

In step S5, following the confirmation of the vehicle speed information in step S4, it is determined whether the vehicle speed sensor value is equal to or less than a predetermined value. If YES (stopped), the process proceeds to step S7. If NO (running), the process proceeds to step S6.
Here, when the vehicle speed sensor value <the stop determination threshold value, it is determined that the vehicle is stopped, and when the vehicle speed sensor value ≧ the stop determination threshold value, it is determined that the vehicle is traveling.

  In step S6, following the determination that the vehicle is traveling in step S5, the normal controller 62b is selected to perform no noise processing, and the process returns to step S1.

  In step S7, following the determination that the vehicle is stopped in step S5, the gradient information is confirmed using the gradient detection means (front and rear G sensor 23), and the process proceeds to step S8.

In step S8, following the confirmation of the gradient information in step S7, it is determined whether or not the front and rear G sensor values are within a predetermined value range. If YES (flat road), the process proceeds to step S11. If NO (inclined road), the process proceeds to step S9.
Here, it is determined that the road is flat when the downhill determination threshold value <the front and rear G sensor value <the uphill determination threshold value. Further, it is determined that the vehicle is downhill when the downhill determination threshold is equal to or greater than the front and rear G sensor value, and the vehicle is determined to be uphill when the front and rear G sensor value is equal to or greater than the uphill determination threshold.

  In step S9, following the determination that the road is an inclined road in step S8, the third controller 65d is selected to perform a process of noise removal degree “low”, and the process proceeds to step S10. By proceeding from step S9 to step S10, the control release determination process shown in FIG. 4 is started.

  In step S11, following the determination that the road is a flat road in step S8, the driving force information or the range signal (drive range or stop range) is confirmed, and the process proceeds to step S12.

  In step S12, following the confirmation of the driving force information or the range signal in step S11, it is determined whether or not the range position is a stop range (P range or N range). If YES (stop range), the process proceeds to step S15. If NO (drive range such as D, R, etc.), the process proceeds to step S13.

  In step S13, following the determination that the driving range is D, R, etc. in step S12, the second controller 65c is selected to perform a process of noise removal degree “medium”, and the process proceeds to step S14. . By proceeding from step S13 to step S14, the control release determination process shown in FIG. 4 is started.

  In step S15, following the determination that the vehicle is in the stop range in step S12, the first controller 65b is selected to perform a process of noise removal degree “large”, and the process proceeds to step S16. By proceeding from step S15 to step S16, the control release determination process shown in FIG. 4 is started.

[Control release determination processing configuration]
FIG. 4 is a flowchart illustrating a flow of control release determination processing executed by the control release determination unit 62 of the noise removal control configuration in the vehicle braking force control apparatus according to the first embodiment. Hereinafter, each step of FIG. 4 showing the control release determination processing configuration will be described.

  In step S21, following the start of the process or the continuation of the noise process in step S23, the operation information of the brake pedal 1 using the brake pedal operation detecting means (the pedal stroke sensor 18, the master cylinder pressure sensor 19, and the brake switch 21). And proceed to step S22.

In step S22, following the operation information confirmation of the brake pedal 1 in step S21, it is determined whether or not the brake pedal 1 is being released (pedal released). If YES (pedal released), the process proceeds to step S24. If NO (pedal depressed), the process proceeds to step S23.
Here, when the pedal stroke amount = 0, it is determined that the pedal is being released, and when the pedal stroke amount ≠ 0, it is determined that the pedal is being depressed.

  In step S23, following the determination in step S22 that the pedal is being depressed, the noise processing by the selected controller (first controller 65b, second controller 65c, third controller 65d) is continued. Return to step S21. That is, when the first controller 65b, the second controller 65c, or the third controller 65d is selected, the noise processing by the selected controller is continued until the brake pedal 1 is released.

  In step S24, following the determination in step S22 that the pedal is being released, the noise processing by the selected controller (first controller 65b, second controller 65c, third controller 65d) is interrupted. The process proceeds to step S25.

  In step S25, following the noise process interruption in step S24, the control intervention determination process shown in FIG. 3 is started. That is, in the control intervention determination process, when the pedal is being released (pedal stroke amount = 0), the process proceeds from step S1 to step S2 to step S3. In step S3, the controller (first control) that performs the noise process The controller 65b, the second controller 65c, and the third controller 65d) are switched to the normal controller 62b, and noise processing is not performed.

Next, the operation will be described.
First, “the problem of the comparative example” will be described. Next, the operation of the vehicle braking force control apparatus according to the first embodiment will be described separately for “noise removal control intervention / release determination processing operation” and “noise removal control operation according to vehicle state”.

[Problems of comparative example]
For example, in the electric booster described in Japanese Patent Application Laid-Open No. 2007-112426, a filter that does not perform filter processing for removing noise superimposed on the pedal stroke amount sensor value is used as a comparative example.

When noise is superimposed on the pedal stroke amount sensor value, the calculated target hydraulic braking force varies under the influence of noise. For example, if the target hydraulic braking force fluctuates when the pedal depressing force is kept almost constant by holding the pedal depressed by the driver while the vehicle is stopped, the variation becomes the variation of the assist force by the motor, and the fluctuating motor control current command Is output, the motor (and unit) vibrates.
Therefore, in the comparative example, the vibration of the motor (and the unit) becomes a source of vibration, which may cause the driver to feel uncomfortable due to minute fluctuations of the brake pedal (pedal vibration) and sound transmitted to the vehicle interior (vehicle interior noise). Yes, it will affect the vehicle quality.

Here, the generation mechanism of “pedal vibration” and “vehicle interior noise” will be described based on FIG. 5 showing an example of a brake system in which an assist force is obtained by an electric booster, as in the first embodiment.
First, as shown in FIG. 5, “pedal vibration” is generated by transmitting vibration of a motor to a brake pedal connected to the input rod using a vibration transmission path with the motor as a vibration source as an input rod. To do. On the other hand, as shown in FIG. 5, “vehicle interior noise” is a vibration transmitted from a dash panel to which a rear housing is fixed, with a vibration transmission path using a motor as a vibration source as a rear housing to a dash panel. Is generated by transmitting sound from the dash panel surface to the vehicle interior.

  Therefore, if a filter or a dead zone is always actively introduced in order to suppress the influence of noise, control responsiveness and stability are impaired. That is, when the brake is operated while the vehicle is not stopped, the generation of the master cylinder pressure is delayed and the stop distance is extended. In addition, when the driver returns the brake pedal in the release direction, the brake response is required when the driver depresses the brake pedal again after returning the brake pedal in the release direction when the vehicle is likely to move or move out. On the other hand, the response request cannot be satisfied.

[Interference / cancellation judgment processing for noise removal control]
In order to solve the problem of the comparative example described above, it is necessary to devise a technique that makes it difficult to be affected by sensor noise while ensuring the responsiveness and stability of a brake required for a stopped vehicle. Hereinafter, based on FIG.3 and FIG.4, the intervention / release determination processing effect | action of the noise removal control which reflects this is demonstrated.

(Not parked)
When the vehicle decelerates due to a brake depression operation during traveling and the pedal depression holding condition is not satisfied, the flow of steps S1 → S2 → step S3 is repeated in the flowchart of FIG.
If the pedal depression holding condition is satisfied but the vehicle is not stopped, the flow of steps S1 → S2 → step S4 → step S5 → step S6 is repeated in the flowchart of FIG.
As described above, when the vehicle is decelerated by the brake depressing operation during traveling, the normal controller 62b is selected in step S3 or step S6, so that no noise removal control is involved and noise processing is not performed.

(During ramp stop)
When the vehicle stops on an uphill or downhill slope, in the flowchart of FIG. 3, the process proceeds from step S1, step S2, step S4, step S5, step S7, step S8, step S9, and step S10. In step S9, by selecting the third controller 65d, execution of the process of the degree of noise removal “low” is started, and in step S10, the control release determination process of FIG. 4 is entered.
In the control release determination process, after the third controller 65d is selected in the control intervention determination process, the flow proceeds from step S21 to step S22 to step S23 in the flowchart of FIG. 4 until the brake pedal 1 is released. Is repeated, and the noise processing by the third controller 65d is continued.
When the brake pedal 1 is released, the process proceeds from step S22 to step S24 → step S25 in the flowchart of FIG. In step S24, the noise processing by the selected third controller 65d is interrupted, and the noise removal control intervention is cancelled. In the next step S25, the control intervention determination process shown in FIG. 3 is started. In the control intervention determination process, the process proceeds from step S1 to step S2 to step S3 because the pedal is being released (pedal stroke amount = 0). . In step S3, the selection of the controller is switched from the third controller 65d that performs noise processing to the normal controller 62b, and noise processing is not performed.

(Stopping on a flat road in the driving range)
When stopping on a flat road with a driving range (D range, R range, etc.) selected, in the flowchart of FIG. 3, step S1, step S2, step S4, step S5, step S7, step S8, step S11, step The process proceeds from S12 to step S13 to step S14. In step S13, by selecting the second controller 65c, execution of the process of the noise removal degree “medium” is started, and in step S14, the control release determination process of FIG. 4 is entered.
In the control release determination process, the flow proceeds from step S21 to step S22 to step S23 in the flowchart of FIG. 4 until the brake pedal 1 is released after the second controller 65c is selected in the control intervention determination process. And the noise processing by the second controller 65c is continued.
When the brake pedal 1 is released, the process proceeds from step S22 to step S24 → step S25 in the flowchart of FIG. In step S24, the noise processing by the selected second controller 65c is interrupted, and the noise removal control intervention is cancelled. In the next step S25, the control intervention determination process shown in FIG. 3 is started. In the control intervention determination process, the process proceeds from step S1 to step S2 to step S3 because the pedal is being released (pedal stroke amount = 0). . In step S3, the selection of the controller is switched from the second controller 65c that performs noise processing to the normal controller 62b, and noise processing is not performed.

(Stopping on a flat road in the stop range)
When stopping on a flat road with a stop range (P range, N range, etc.) selected, in the flowchart of FIG. 3, step S1, step S2, step S4, step S5, step S7, step S8, step S11, step The process proceeds from S12 to step S15 to step S16. In step S15, by selecting the first controller 65b, the process of the noise removal degree “high” is started, and in step S16, the control release determination process of FIG. 4 is entered.
In the control release determination process, after the first controller 65b is selected in the control intervention determination process, the flow proceeds from step S21 to step S22 to step S23 in the flowchart of FIG. 4 until the brake pedal 1 is released. And the noise processing by the first controller 65b is continued.
When the brake pedal 1 is released, the process proceeds from step S22 to step S24 → step S25 in the flowchart of FIG. In step S24, the noise processing by the selected first controller 65b is interrupted, and the noise removal control intervention is cancelled. In the next step S25, the control intervention determination process shown in FIG. 3 is started. In the control intervention determination process, the process proceeds from step S1 to step S2 to step S3 because the pedal is being released (pedal stroke amount = 0). . In step S3, the selection of the controller is switched from the first controller 65b that performs noise processing to the normal controller 62b, and noise processing is not performed.

[Noise removal control action according to vehicle condition]
As described above in the noise removal control intervention / release determination process, the vehicle state is (not stopped), (stopped on the ramp), (stopped on a flat road in the driving range), (flat road in the stop range) When it is divided into (stopped), the noise removal control action in each vehicle state will be described.

(Not parked)
In the brake operation scene from the running state, high brake response is required in order to achieve vehicle deceleration and vehicle stop at the target position according to the driver's braking intention appearing in the operation of the brake pedal 1.
In contrast, when the vehicle is not stopped, as described above, there is no noise removal control intervention, the normal controller 62b is selected, and noise processing is not performed, so that high brake response is ensured.
Therefore, when the brake is operated while the vehicle is not stopped, the master cylinder pressure is generated due to high brake response, and the vehicle is stopped at the target position without increasing the stop distance.

(During ramp stop)
The ramp stop scene such as uphill or downhill is a scene in which the vehicle is likely to start when the brake pedal 1 is returned to the release direction. In this case, when the brake is stepped on again due to vehicle slipping or the like, brake response is required to quickly suppress vehicle slipping or the like.
On the other hand, while the vehicle is stopped on the ramp, as described above, although the noise removal control intervenes, the third controller 65d is selected and the processing of the noise removal degree “low” is performed, so that the brake responsiveness is achieved. Is secured.
Therefore, when the vehicle starts to move when the brake pedal 1 is returned to the release direction during stopping on the ramp, if the brake is depressed again, the hydraulic braking force is generated with good response, and the vehicle can be quickly prevented from sliding down. .

(Stopping on a flat road in the driving range)
In a flat road stop scene with the D range, R range, etc. selected, the vehicle will be allowed to move if the braking force is reduced. Therefore, when the brake pedal 1 is returned to the release direction and the brake is depressed again, the brake response Sex is required. However, since the road is flat, the vehicle does not slide down as in the ramp stop scene, and the required brake response may be lower than that in the ramp stop scene.
On the other hand, while the vehicle is stopped on a flat road in the driving range, as described above, although the noise removal control intervenes, the second controller 65c is selected, and the process of the noise removal degree “medium” is performed. Noise is reduced while maintaining brake response.
Therefore, when the vehicle starts to move when the brake pedal 1 is returned to the release direction while the vehicle is stopped on a flat road in the drive range, a hydraulic braking force is generated when the brake is stepped on again, thereby suppressing the vehicle from starting to move. Further, noise that causes a decrease in sound vibration performance is suppressed as compared to when the vehicle is stopped on a ramp.

(Stopping on a flat road in the stop range)
In a flat road stop scene with the N range, P range, etc. selected, the vehicle does not start even if the braking force is reduced. Therefore, when the brake pedal 1 is returned to the release direction and the brake is stepped on again, the brake response is reduced. Is not required. That is, this is a flat road stop mode in which noise reduction is more important than brake response.
On the other hand, while stopping on a flat road in the stop range, as described above, the noise removal control intervenes and the first controller 65b is selected, and the process of the noise removal degree “large” is performed. Noise is reliably reduced.
Therefore, even when noise is superimposed on the pedal stroke amount sensor value from the pedal stroke sensor 18 during stopping on a flat road in the stop range, the superimposed noise is removed by the first controller 65b having a noise removal degree “large”. The Accordingly, pedal vibrations and vehicle interior noises that give the driver a sense of incongruity when the vehicle stops with high driver sensitivity to vibrations and sounds are suppressed.

Summarizing the noise removal control action according to the above vehicle state,
(Non-stopped) ··· No noise removal (follows high responsiveness requirements)
(During stopping on the ramp) ... Low degree of noise removal (high demand for responsiveness)
(During stopping on a flat road in the driving range) ... Medium degree of noise removal (requesting responsiveness)
(During stopping on a flat road in the stop range) ... High degree of noise removal (low responsiveness requirement)
It becomes.

Further, when the first controller 65b, the second controller 65c, or the third controller 65d is selected in the control intervention determination process, the noise process by the selected controller is continued until the brake pedal 1 is released. . Then, when the pedal is being released (pedal stroke amount = 0), the noise processing by the selected controller is interrupted, and thereafter, switching to the normal controller 62b is performed.
For example, if the selected controller is switched while the brake pedal 1 is depressed (holding, during stroke), the target hydraulic pressure braking force fluctuates due to the difference in the degree of noise removal. Changes to the driver.
On the other hand, when one controller that intervenes in the noise removal control is selected, the noise processing by the selected one controller is continued until the pedal is released, so that the brake pedal 1 is being depressed. The controller does not switch. Therefore, when one controller that intervenes in the noise removal control is selected, it is possible to prevent the driver from feeling uncomfortable due to the change in the pedal reaction force.

[Pedal vibration / car interior noise suppression]
As described in the problem of the comparative example, in the case of a brake system that obtains assisting force by an electric booster, pedal vibration and vehicle interior noise generated by using a motor as a vibration source when the vehicle is stopped give the driver a sense of incongruity. It also affects vehicle quality. For this reason, it is necessary to surely suppress pedal vibration and vehicle interior noise that use the motor as a vibration source. Hereinafter, the pedal vibration / vehicle interior noise suppressing action reflecting this will be described with reference to FIG.

  First, the operation flow until the master cylinder pressure is generated based on the brake pedal operation will be described with reference to FIG.

  When a pedal stroke is generated by operating the brake pedal, the generated pedal stroke is detected by the pedal stroke sensor 18, and the pedal stroke amount sensor value is input to the stroke sensor signal processing unit of the brake controller 6. The stroke sensor signal processing unit of the brake controller 6 calculates a target hydraulic braking force based on the pedal stroke amount sensor value, converts the target hydraulic braking force into a ball screw position, and inputs it to the motor speed control unit as a ball screw position command. The motor speed control unit of the brake controller 6 inputs a ball screw position command and a ball screw position sensor value from the motor resolver 20 (resolver sensor), calculates a motor control current command by feedback control for matching both values, and drives the motor. Output to circuit 7 (motor current control unit).

  In the motor drive circuit 7, the motor control current command and the motor control current sensor value from the current sensor 26 are input, the motor control current is calculated by feedback control for matching both values, and is output to the electric motor 10 (motor). . Thereby, the electric motor 10 outputs a motor torque corresponding to the motor control current, and converts the assist force in the rotational direction by the motor torque into an axial piston thrust by the ball screw. Then, in the master cylinder 3, a master cylinder pressure (M / C hydraulic pressure) is generated by piston thrust.

That is, a pedal stroke amount sensor value and a ball screw position sensor value are input to the brake controller 6, and a motor control current command is output from the brake controller 6.
Among these, the stroke sensor noise superimposed on the pedal stroke amount sensor value (stroke sensor signal) has a peak in a certain frequency range in the frequency characteristics. At this time, motor speed noise is also superimposed on the ball screw position sensor value (motor speed signal), and this motor speed noise has a peak in a frequency range different from the stroke sensor noise in the frequency characteristics. Therefore, motor control current noise (= motor speed noise + stroke sensor noise) is superimposed on the motor control current command (motor control current).

  This motor control current noise becomes motor vibration of the electric motor 10, and in the vibration level characteristics, pedal vibration having a peak due to the motor speed noise and a peak due to the stroke sensor noise is generated. At the same time, it was found that in the sound pressure level characteristics, vehicle interior noise having a peak due to motor speed noise and a peak due to stroke sensor noise occurs.

In contrast, in the first embodiment, a filter for reducing the gain of the peak frequency is mounted on the input side (pedal stroke amount sensor value, ball screw position sensor value) and output side (motor control current command) of the brake controller 6. The first controller 65b, the second controller 65c, and the third controller 65d were used. Then, switching between “the first controller 65b and the second controller 65c that are not easily affected by sensor noise” and “the third controller 65d that prioritizes responsiveness” is performed according to the vehicle state.
Therefore, when the vehicle is stopped on a flat road where a controller that is low in background vibration and noise and is not easily affected by sensor noise is selected, pedal vibration and vehicle interior noise using the electric motor 10 as a vibration source are reliably suppressed. The

Next, the effect will be described.
In the vehicle braking force control apparatus according to the first embodiment, the effects listed below can be obtained.

(1) A brake controller 6 that calculates a target hydraulic braking force based on a sensor detection value (pedal stroke amount sensor value) from a brake operation sensor (pedal stroke sensor 18) that detects a brake operation by a driver, and the target hydraulic pressure control. A vehicle braking force control device comprising: a booster (electric booster 2) whose assist force is controlled based on power; and a master cylinder 3 that generates a master cylinder pressure by a piston thrust obtained by adding the assist force to a pedal depression force. In
Vehicle state detection means (pedal stroke sensor 18, master cylinder pressure sensor 19, brake switch 21, wheel speed sensor 22, front and rear G sensor 23, range position sensor 24) for detecting the vehicle state is provided,
The brake controller 6 determines a vehicle state based on a detection value from the vehicle state detection unit, and determines that the brake operation sensor is more flat when it is determined that the road is flat and stopped than when it is determined that the road is inclined and stopped. Noise removal control is performed to increase the degree of removal of noise superimposed on the sensor detection value of the (pedal stroke sensor 18) (controller selection unit 65).
For this reason, it is possible to ensure the responsiveness required when the brake is stepped on again on an inclined road stop scene, and to suppress noise that causes a decrease in sound vibration performance on other flat road stop scenes.

(2) The degree of noise removal when the brake controller 6 determines that the vehicle is stopped is “inclined road” <“flat road and drive range” <“flat road and stop range”. (Figure 3).
For this reason, in addition to the effect of (1), when selecting a drive range where the vehicle may move due to a brake release operation in a flat road stop scene, the brake responsiveness required when re-depressing is secured while suppressing noise In addition, when a stop range is selected in which the vehicle does not start even when the brake is released, noise that causes a reduction in sound vibration performance can be removed.

(3) The brake controller 6 sets the timing for changing the degree of noise removal when the brake pedal operation is released (FIG. 4).
For this reason, in addition to the effects of (1) or (2), when the degree of noise removal during the depression of the brake pedal 1 is set to a predetermined level, the driver feels uncomfortable due to the change in the pedal reaction force during the depression of the pedal. Giving can be prevented.

(4) The booster is an electric booster 2 that uses the thrust of the electric motor 10 as an assist force,
A motor speed sensor (motor resolver 20) for detecting the motor speed of the electric motor 10 is provided;
The brake controller 6 performs noise removal control on the pedal operation sensor value (pedal stroke amount sensor value) on the input side, the motor speed sensor value (ball screw position sensor value), and the motor control current command on the output side (FIG. 6). ).
For this reason, in addition to the effects (1) to (3), pedal vibration and vehicle interior noise generated by using the electric motor 10 as a vibration source can be reliably suppressed when stopping on a flat road with low background vibration and background noise. it can.

  The vehicular braking force control apparatus according to the present invention has been described based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and the claims relate to each claim. Design changes and additions are allowed without departing from the scope of the invention.

  In Example 1, the example of the brake system using the electric booster 2 which uses the thrust of the electric motor 10 as an assist force as a booster was shown. However, the booster may be a brake system using another booster such as a hydraulic booster or a pneumatic booster. In short, any brake system including a booster that controls assist force by a control command to a booster actuator based on a target hydraulic braking force can be applied.

  In Example 1, the example which uses the pedal stroke sensor 18 as a brake operation sensor which detects the brake operation by a driver was shown. However, as a brake operation sensor, a pedal reaction force sensor, a master cylinder pressure sensor, or the like may be used. Further, an example in which two or more of these sensors are combined may be used.

  In the first embodiment, an example in which the first controller 65b, the second controller 65c, and the third controller 65d in which a filter for reducing the gain of the peak frequency is mounted is used as the noise removing unit. However, as noise removal means, noise such as LPF (Low Path Filter), BPF (Band Path Filter), HPF (High Path Filter), averaging processing, and oversampling (upsampling), which are general methods, are used. All of smoothing arithmetic processing to be removed and the like are included.

  The first embodiment shows an example in which each signal on the input side (pedal stroke amount sensor value, ball screw position sensor value) and output side (motor control current command) of the brake controller 6 is used as a noise removal target signal of the noise removal means. It was. However, the noise removal target signal of the noise removal means may include a sensor detection value (pedal stroke amount sensor value) from the brake operation sensor (pedal stroke sensor 18). For example, only the pedal stroke amount sensor value, the pedal stroke amount sensor value and the ball screw position sensor value, or the pedal stroke amount sensor value and the motor control current command may be used.

  In the first embodiment, the vehicle braking force control device according to the present invention is applied to an electric vehicle such as an electric vehicle or a hybrid vehicle. However, the present invention can also be applied to an engine vehicle that employs a brake system that uses an electric booster or the like as a booster.

1 Brake pedal 2 Electric booster (Booster)
3 Master cylinder 4 Brake hydraulic actuator 5FL, 5FR, 5RL, 5RR Wheel cylinder 6 Brake controller 61 Control intervention determination unit 62 Control release determination unit 62b Normal controller 63 Vehicle state detection unit 64 Vehicle state determination unit 65 Controller selection unit 65b First controller 65c Second controller 65d Third controller 7 Motor drive circuit 9 Input rod 10 Electric motor 11 Primary piston 13, 13 Spring 18 Pedal stroke sensor (brake operation sensor, vehicle state detection means)
19 Master cylinder pressure sensor (vehicle state detection means)
20 Motor resolver 21 Brake switch (vehicle state detection means)
22 Wheel speed sensor (vehicle state detection means)
23 Front / rear G sensor (vehicle state detection means)
24 range position sensor (vehicle state detection means)
25 Other sensors and switches 26 Current sensor

Claims (4)

A brake controller that calculates a target hydraulic braking force based on a sensor detection value from a brake operation sensor that detects a brake operation by a driver; a booster that controls an assisting force based on the target hydraulic braking force; In a vehicular braking force control device comprising: a master cylinder that generates a master cylinder pressure by piston thrust applied with assist force;
Vehicle state detection means for detecting the vehicle state is provided;
The brake controller determines a vehicle state based on a detection value from the vehicle state detection means, and determines that the brake operation sensor has a flat road and a stop when compared with a case where it is determined that the road is a ramp and stopped. A vehicle braking force control device that performs noise removal control that increases a degree of removal of noise superimposed on a sensor detection value. In the vehicle braking force control device according to claim 1,
When the brake controller determines that the vehicle is stopped, the degree of noise removal is “inclined road” <“flat road and drive range” <“flat road and stop range”. A braking force control device for a vehicle. In the vehicle braking force control device according to claim 1 or 2,
The vehicle braking force control device according to claim 1, wherein the brake controller sets a timing of changing the degree of noise removal when the brake pedal operation is released. The vehicular braking force control device according to any one of claims 1 to 3,
The booster is an electric booster whose assist force is the thrust of an electric motor,
A motor speed sensor for detecting a motor speed of the electric motor is provided;
The brake controller according to claim 1, wherein the brake controller performs noise removal control on an input side pedal operation sensor value, a motor speed sensor value, and an output side motor control current command.