JP5830977B2 - Vehicle brake control system - Google Patents

Description

  The present invention relates to a cooperative brake control device for a vehicle that obtains a braking force required by a driver by cooperatively controlling a hydraulic brake that generates a hydraulic braking force and a regenerative brake that generates a regenerative braking force.

  A vehicle such as an electric vehicle that travels using an electric motor as a drive source includes a hydraulic brake that generates a hydraulic braking force and a regenerative brake that generates a regenerative braking force, and the braking force required by the driver by cooperatively controlling both brakes. Like to get.

  Here, the hydraulic brake is a brake that rotates together with the wheels by operating the brake pads by supplying the hydraulic pressure generated in the master cylinder when the driver depresses the brake pedal to, for example, the wheel cylinder of the disc brake device of each wheel. When the disc is sandwiched between brake pads, braking is applied to the rotation of the wheel by frictional resistance (hydraulic braking force) generated between the two. The regenerative brake converts the kinetic energy into electric energy by causing the electric motor to function as a generator during deceleration and stores it in the battery, and uses the regenerative torque generated by the rotational resistance of the electric motor as the regenerative braking force. It is.

  By the way, in a vehicle equipped with a hydraulic brake and a regenerative brake, the braking force is distributed so as to mainly use the regenerative braking force in order to collect more kinetic energy during deceleration and improve fuel efficiency. However, the maximum regenerative braking force that can be generated by the regenerative brake is limited by the maximum regenerative energy that the battery can accept. For this reason, when the braking force is insufficient only with the regenerative braking force limited to the maximum regenerative braking force with respect to the braking force requested by the driver, the shortage is compensated with the hydraulic braking force. This will be described below with reference to FIG.

That is, FIG. 4A is a diagram showing the time change of the braking force, and FIG. 4B is a diagram showing the time change of the hydraulic pressure of the hydraulic brake, and the braking force F requested by the driver when the vehicle decelerates. _{0 (request} total braking force) is shows by the solid line in FIG. 4 (a), showing a regenerative braking force F ₁ in this case by a broken line. At this time, the maximum regenerative braking force is (F ₁ ) _max shown in the figure. In the cooperative control of the braking force shown in FIG. 4A, the regenerative braking force is increased by the driver's braking operation, and reaches the maximum regenerative braking force (F ₁ ) _max at the time t ₁ shown in the figure. After the illustrated time t _1, the maximum regenerative braking force (F ₀₁ ) _max does not cover the braking force F ₀ required by the driver, and the deficit (F _0- (F ₁ ) _max ) is used to control the hydraulic brake. Supplementing with the power F ₂ is performed. The time variation of the fluid pressure P of the hydraulic brake in this case is shown in FIG. 4 (b), when the hydraulic pressure P as shown P ₁ is minute, holding the brake pads in the brake system Since the force (pressing force against the brake disc, etc.) is small and the brake pad is likely to vibrate, an unpleasant sound called “brake squeal” is generated.

  Therefore, Patent Document 1 includes a brake squeal detection unit that detects a brake squeal of a hydraulic brake, and when the brake squeal is detected by the brake squeal detection unit, the hydraulic braking force is increased or decreased, and the increase or decrease There has been proposed a braking force control device that reduces or increases the regenerative braking force by a reduced amount to prevent the occurrence of brake squeal while ensuring a required total braking force.

Japanese Patent Laid-Open No. 10-329681

  However, the braking force control device proposed in Patent Document 1 requires a brake squeal detecting means for detecting the brake squeal, which causes an increase in cost and weight, and the hydraulic braking force is detected after the brake squeal is detected. There is a problem that a brake squeal occurs although it takes only a short time to change.

  The present invention has been made in view of the above-mentioned problems, and the intended process is to reliably generate a brake squeal while ensuring a braking force of a magnitude required by the driver without causing an increase in cost or an increase in weight. Another object of the present invention is to provide a cooperative brake control device for a vehicle that can be prevented.

In order to achieve the above-mentioned object, the invention according to claim 1 is a vehicle cooperation that obtains the braking force requested by the driver by cooperatively controlling the hydraulic brake that generates the hydraulic braking force and the regenerative brake that generates the regenerative braking force. In the brake control device, a minimum hydraulic pressure, which is a minimum hydraulic pressure at which the hydraulic brake does not squeal, is set, and when the hydraulic brake is used, the hydraulic brake is set to a hydraulic pressure higher than the minimum hydraulic pressure. A hydraulic pressure actuating device that sets the maximum regenerative braking force of the regenerative brake, compensates for the shortage of the maximum regenerative braking force with respect to the braking force requested by the driver with the hydraulic braking force, and generates the hydraulic braking force. When the pressure is less than the minimum hydraulic pressure, the hydraulic pressure is increased to be higher than the minimum hydraulic pressure to increase the hydraulic braking force, and the regenerative braking force is decreased by the increase of the hydraulic braking force. To do.

According to a second aspect of the present invention, in the first aspect of the invention, a stroke sensor for detecting a stroke of the brake pedal or a pedal force sensor for detecting a pedal force applied to the brake pedal is provided, and an acceleration of a stroke detected by the stroke sensor or The braking force required by the driver is predicted based on the acceleration of the pedal force change detected by the pedal force sensor.

The invention according to claim 3 is the invention according to claim 1 or 2 , wherein after the braking force requested by the driver is obtained by cooperatively controlling the hydraulic brake and the regenerative brake, When the braking force requested by the driver increases, the regenerative braking force is first increased, and then the hydraulic braking force is increased.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, after the braking force requested by the driver is obtained by cooperatively controlling the hydraulic brake and the regenerative brake, the driver When the braking force required by is reduced, the hydraulic pressure of the hydraulic brake is first lowered to the lowest hydraulic pressure to reduce the hydraulic braking force, and then the regenerative braking force is reduced.

According to the first aspect of the present invention, the minimum value of the hydraulic pressure at which no brake squeal is generated is set in the hydraulic brake, and the hydraulic braking force is generated to compensate for the shortage of the maximum regenerative braking force with respect to the braking force requested by the driver. When the hydraulic pressure to be applied is less than the minimum hydraulic pressure, the hydraulic pressure is increased to be higher than the minimum hydraulic pressure to increase the hydraulic braking force. Therefore, the holding force of the brake pad of the hydraulic brake provided on each wheel ( It is possible to prevent the occurrence of vibration by increasing the pressing force), and reliably prevent the occurrence of brake squeal accompanying the vibration of the brake pad. In addition, since the regenerative braking force is decreased by the increase of the hydraulic braking force, the braking force required by the driver can be stably obtained.

According to the second aspect of the present invention, the braking force required by the driver is predicted based on the acceleration of the stroke or the change in the pedaling force detected by the existing stroke sensor or the pedaling force sensor, and the liquid is calculated from the predicted braking force. Since the hydraulic pressure required for the pressure brake is obtained, the brake squeal detecting means for detecting the brake squeal becomes unnecessary, and the cooperative brake control device can be reduced in cost and weight. If the calculated hydraulic pressure is less than the minimum hydraulic pressure, the hydraulic pressure is increased above the minimum hydraulic pressure to increase the hydraulic braking force, and the regenerative braking force is decreased by the increase in the hydraulic braking force. Is made.

According to the invention described in claim 3 , after the braking force requested by the driver is obtained by cooperatively controlling the hydraulic brake and the regenerative brake, when the braking force requested by the driver increases, the regeneration is first performed. Since the braking force is increased, kinetic energy can be effectively recovered as electric energy to improve fuel efficiency.

According to the invention described in claim 4 , after the braking force requested by the driver is obtained by cooperatively controlling the hydraulic brake and the regenerative brake, when the braking force requested by the driver is reduced, first the liquid brake Since the hydraulic brake pressure is reduced to the lowest hydraulic pressure to reduce the hydraulic braking force and then the regenerative braking force is reduced, the regenerative braking force is used as long as possible to recover kinetic energy as electrical energy. can do. In addition, since the hydraulic pressure of the hydraulic brake is kept at the minimum hydraulic pressure, for example, the braking force when the regenerative braking is terminated due to a decrease in the vehicle speed and only the hydraulic braking force is applied, such as cooperative control when stopping the vehicle. The discomfort of the driver, such as a discontinuity feeling (G missing feeling, etc.) can be eliminated.

1 is a system configuration diagram of a vehicle cooperative brake control device according to the present invention. FIG. (A) is a figure which shows the time change of the braking torque in the cooperative brake control apparatus of the vehicle which concerns on this invention, (b) is a figure which shows the time change of the hydraulic pressure of a hydraulic brake. It is a flowchart which shows the control procedure of the cooperative brake control apparatus which concerns on this invention. (A) is a figure which shows the time change of the braking torque in the conventional cooperative brake control apparatus, (b) is a figure which shows the time change of the hydraulic pressure of a hydraulic brake.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a system configuration diagram of a cooperative brake control device according to the present invention. A vehicle equipped with the cooperative brake control device is an electric vehicle that runs using an electric motor 1 as a drive source, and is a pair of left and right drive wheels. The front wheel 2 is rotationally driven by the power transmitted from the electric motor 1 through the reduction gear (R / G) 3. The electric vehicle includes a regenerative brake 4 that generates a regenerative braking force by causing each electric motor 1 to function as a generator during deceleration, and a hydraulic brake that generates a hydraulic braking force by a mechanical frictional force by hydraulic pressure. 5 is provided.

  The regenerative brake 4 includes an electric motor 1 and a motor controller 6 for controlling them. When the driver releases the depression of the accelerator pedal 7, the information is transmitted from the accelerator position sensor 8 to the motor controller 6, and the motor The controller 6 causes each electric motor 1 to function as a generator. Then, the power generation load of each electric motor 1 that functions as a generator is applied to each front wheel 2 via the speed reducer 3, and a regenerative braking force equivalent to an engine brake is applied to each front wheel 2.

  The hydraulic brake 5 includes a brake pedal 9 and a brake booster 10 that assists the depression force (depression force), a master cylinder 11 that generates a required hydraulic pressure when the brake pedal 9 is depressed, a pair of left and right front wheels 2 and a rear wheel 12. Are provided with a brake device 13, a hydraulic pressure control unit 14 for generating a required hydraulic pressure, and the like, and a stroke sensor 15 for detecting the stroke of the brake pedal 9 is provided in the vicinity of the brake pedal 9. It has been. Instead of the stroke sensor 15, a pedal force sensor that detects the depression force (depression force) of the brake pedal 9 may be provided.

  Here, the brake devices 13 respectively provided on the front wheel 2 and the rear wheel 12 are disc brakes, and hydraulic pressure supplied to a brake disc 13a that rotates together with the front wheel 2 or the rear wheel 12 and a wheel cylinder (not shown). When the hydraulic pressure is supplied to the wheel cylinder, the brake pad 13b operates to pinch the brake disc 13a, and a mechanical hydraulic braking force is generated by the frictional resistance between the brake pads 13b. .

  The hydraulic pressure control unit 14, the master cylinder 11 and the hydraulic pressure control unit 14 are connected by a brake pipe 16, and the wheel cylinders of the brake devices 13 provided on the front wheel 2 and the rear wheel 12 respectively are brake pipes. 17 are connected to the hydraulic pressure control unit 14 respectively.

  By the way, the cooperative brake control device 18 according to the present invention obtains the braking force requested by the driver by cooperatively controlling the regenerative brake 4 that generates the regenerative braking force and the hydraulic brake 5 that generates the hydraulic braking force. The output of the stroke sensor 15 that detects the stroke of the brake pedal 9, the output from the pedal force sensor that detects the depression force (depression force) of the brake pedal 9, or the liquid in the master cylinder 11 that is generated when the brake pedal 9 is depressed. The braking force requested by the driver is detected according to the pressure, and the regenerative brake 4 and the hydraulic brake 5 are cooperatively controlled. Furthermore, a function for predicting the braking force requested by the driver based on the stroke acceleration of the brake pedal 9 detected by the stroke sensor 15 is provided. That is, when the driver depresses the brake pedal 9 (stroke), the operation speed decreases as the driver approaches the desired braking force. Therefore, the change in the operation speed is detected, and the braking force requested by the driver is determined. Predict. Information on the braking force requested by the driver is transmitted from the cooperative brake control device 18 to the motor controller 6, and information on the maximum regenerative braking force is transmitted from the motor controller 6 to the cooperative brake control device 18. The cooperative brake control device 18 transmits necessary brake fluid pressure information to the fluid pressure control unit 14. When a pedal force sensor is used instead of the stroke sensor 15, the braking force required by the driver is predicted based on the acceleration of the pedal force change detected by the pedal force sensor.

  Thus, the cooperative brake control device 18 according to the present invention distributes the braking force so as to mainly use the regenerative braking force in order to improve mileage by collecting the kinetic energy at the time of deceleration of the vehicle as electric energy. However, the maximum regenerative braking force that can be generated by the regenerative brake 4 is limited by the maximum value of regenerative energy that the battery can accept. For this reason, when the braking force is insufficient only by the regenerative braking force limited to the maximum regenerative braking force with respect to the braking force requested by the driver, the shortage is compensated by the hydraulic braking force generated by the hydraulic brake 5. I am doing so. In this case, when the hydraulic braking force to be supplemented is very small, the holding force of the brake pad 13b of each brake device 13 is small, and the brake pad 13b easily vibrates, so that the brake squeal is generated as described above. is there.

  Therefore, in the present invention, the lowest hydraulic pressure that is the lowest hydraulic pressure at which no brake squeal is generated in the hydraulic brake 5 and the highest regenerative braking force of the regenerative brake 4 are set. Then, the regenerative brake 4 is operated with respect to the braking force required by the driver, and the shortage that cannot be achieved by the maximum regenerative braking force of the regenerative energy is compensated by the hydraulic braking force. At this time, if the hydraulic pressure that generates the hydraulic braking force is less than the minimum hydraulic pressure, the hydraulic pressure is increased above the minimum hydraulic pressure to increase the hydraulic braking force, and the regeneration is increased by the increase in the hydraulic braking force. The braking force is reduced. This will be described below with reference to FIG.

That is, FIG. 2 (a) is a diagram showing the time change of the braking force F in the present invention, and FIG. 2 (b) is a diagram showing the time change of the hydraulic pressure P of the hydraulic brake 5. Is indicated by the solid line in FIG. 2 (a). In this case, the maximum regenerative braking force is (F ₁ ) _max shown in FIG. 2 (a), and the minimum hydraulic pressure at which no brake squeal is generated is P _min shown in FIG. 2 (b). According to this, in the cooperative control of the braking force shown in FIG. 2A, the regenerative braking force is increased by the driver's braking operation, and reaches the maximum regenerative braking force (F ₁ ) _max at the time t ₁ shown in the figure. After the illustrated time t _1, the maximum regenerative braking force (F ₁ ) _max alone cannot cover the braking force F ₀ required by the driver, and the deficit (F ₀ − (F ₁ ) _max ) and thus supplemented by the hydraulic braking force F _2. The time change of the hydraulic pressure P of the hydraulic brake 5 at this time is shown by a broken line in FIG. 2B, but the shortage (F _1- (F ₁ ) _max ) is simply _calculated by the hydraulic braking force of the hydraulic brake 5. In order to compensate by F ₂ , as shown by the broken line, the hydraulic pressure P becomes minute, and the hydraulic pressure becomes smaller than the lowest hydraulic pressure P _min at which no brake squeal occurs. Note that F ₁ in FIG. 2A indicates the time change of the regenerative braking force when this control is continued, and the shortage (difference between F ₀ and F ₁ ) is the hydraulic braking force F ₂ of the hydraulic brake 5. It becomes.

In the present embodiment, the braking force required by the driver is predicted from the change in the depression (stroke) operation speed of the brake pedal 9 by the driver until time t ₁ when the maximum regenerative braking force (F ₁ ) _max is reached, Thus when the fluid pressure P is less than the minimum pressure P _min in small, as well as to increase the hydraulic braking force F ₂ by increasing the hydraulic pressure P in the above minimum fluid pressure P _min as indicated by the solid line , is decreased by _{'(ΔF = F 1 -F 1} ) as indicated by the arrow to' the increase only the regenerative braking force _{F 1} of the hydraulic braking force _{F 2} from _{F 1} shown in FIG. 2 (a) _{F 1} I am doing so. In other words, when the braking force requested by the driver is achieved at a hydraulic pressure P that is less than the maximum regenerative braking force (F ₁ ) _max and the minimum hydraulic pressure P _min , the hydraulic pressure of the hydraulic brake 5 P is to reduce the regenerative braking force F ₁ to be greater than the minimum pressure P _min, it is operated with a large hydraulic pressure P than the minimum pressure P _min of the hydraulic brake 5. That is, when a braking force (braking force requested by the driver) that slightly exceeds the maximum regenerative braking force (F ₁ ) _max is predicted, the increase in the regenerative braking force ends before reaching time t ₁ , The increase of the hydraulic pressure P of the hydraulic brake 5 is started.

In the present invention, after the braking force F ₀ for requesting cooperative control to the driver the regenerative brake 4 and the hydraulic brake 5 obtained, if the braking force F0 required by the driver has increased (the driver When the brake pedal 9 is further depressed), the regenerative braking force F ₀ is _first increased to the maximum regenerative braking force (F ₁ ) _max , and then the hydraulic braking force F ₂ is increased. On the contrary, if after the braking force F ₀ for requesting cooperative control to the driver the regenerative brake 4 and the hydraulic brake 5 obtained, the braking force F ₀ for the driver to request a decrease (driver the but when the operation of returning the brake pedal 9) causes first lowering the fluid pressure P of the hydraulic brake 5 to the minimum pressure P _min to reduce the hydraulic braking force F2, then reducing the regenerative braking force F ₁ Control is made.

  FIG. 2 shows this state, and specifically shows a state in which the driver releases the brake when the vehicle stops. At time t2, the braking force F0 requested by the driver begins to decrease (the driver begins to release the brake). First, the hydraulic pressure P of the hydraulic brake 5 is lowered to the lowest hydraulic pressure Pmin to reduce the hydraulic braking force F2, and then the regenerative braking force F1 'is reduced. Thereafter, when the vehicle speed decreases and reaches a speed at which predetermined regenerative braking ends, the increase of the hydraulic pressure P of the hydraulic brake 5 is started, and the braking force of the regenerative braking is replaced with the braking force of the hydraulic brake 5.

  Next, a control procedure in the cooperative brake control device 20 according to the present invention will be described below according to the flowchart shown in FIG.

First, it is determined whether or not a brake operation has been performed (step S1). When a brake operation is performed (when the determination result in step S1 is Yes), the stroke and stroke of the brake pedal 9 detected by the stroke sensor 15 are determined. The braking force (hereinafter referred to as “total braking force”) F0 required by the driver is predicted based on the change rate of the stroke and the acceleration of the stroke change (step S2). In particular, at the changing speed and the acceleration of the stroke, to predict the final stroke end position of the pedal operation of the driver, to predict the total braking force F ₀ for the driver to request. Then, allocating the total braking force _{F 0} to the regenerative braking force _{F 1} and the hydraulic braking force _{F 2} (Step S3). Specifically, the total braking force F ₀ is allocated to the regenerative braking force F ₁ and the hydraulic braking force F ₂ by the following equation.

When the total braking force F ₀ is less than or equal to the maximum regenerative braking force (F ₁ ) _max :
Regenerative braking force F ₁ = Total braking force F ₀
When the total braking force F ₀ is greater than the maximum regenerative braking force (F ₁ ) _max :
Regenerative braking force F ₁ = Maximum regenerative braking force (F ₁ ) _max
Hydraulic braking force F ₂ = (total braking force F ₀ ) − (regenerative braking force F ₁ )
Next, calculate the fluid pressure P of the hydraulic brake 5 which corresponds to the hydraulic braking force F ₂ which is allocated by the above equation (step S4), and whether the fluid pressure P is minimum pressure P _min or higher ( P ≧ P _min ) is determined (step S5). When the hydraulic pressure P is less than the minimum hydraulic pressure P _min (P <P _min ) (when the determination result in step S5 is No), there is a possibility that brake squeal occurs in the hydraulic brake 5. there increases the hydraulic braking force F ₂ by increasing the hydraulic pressure P in the minimum of pressure P _min in order (step S6), and the increase by the hydraulic braking force F ₂ to reduce the regenerative braking force (step S7).

When the hydraulic pressure P is equal to or higher than the minimum hydraulic pressure P _min (P ≧ P _min ) (when the determination result in step S5 is Yes) and when the processing of step S7 is completed, has the total braking force F ₀ increased or decreased? It is determined whether or not (step S8).

The case when there is increase or decrease in the total braking force F ₀ (one if the determination result is Yes in at step S8), and whether a reduction or an increase is determined (step S9), and an increase in first increase the regenerative braking force _{F 1} (step S10), and the regenerative braking force _{F 1} is the highest regenerative braking force _{(F 1)} after reaching the _max increases the hydraulic braking force _{F 2} (step S11), and thereafter, or This process is repeated (step S14). Further, in the case of reduction, first to lower the fluid pressure P of the hydraulic brake 5 to the minimum pressure P _min to reduce the hydraulic braking force F2 (step S12), the allowed then to reduce the regenerative braking force F ₁ ( Thereafter, the above process is repeated (step S14). Note that if there is no increase or decrease in the total braking force _{F 0} (when the determination result at step S9 is No), the process of step S9~S13 is skipped and processing in step S1~S8 are repeated (step S14 ).

As described above, according to the present invention, the minimum value (minimum hydraulic pressure P _min ) of the hydraulic pressure P at which no brake squeal is generated in the hydraulic brake 5 is set, and the braking force (total braking force) required by the driver is set. When the hydraulic pressure P that generates the hydraulic braking force F ₂ that compensates for the shortage of the maximum regenerative braking force (F ₁ ) _max with respect to F ₀ is less than the minimum hydraulic pressure P _min , the hydraulic pressure P is set to the minimum hydraulic pressure P _min. since you increase the hydraulic braking force F ₂ is increased to above, it is possible to prevent generation of vibration by increasing the retaining force of the brake pad 13b of the brake device 13 provided on the rear wheel 12 and the pair of front wheels 2 Thus, it is possible to reliably prevent the occurrence of brake squeal accompanying vibration of the brake pad 13b. Also, since you reduce the increment only the regenerative braking force F ₁ of the hydraulic braking force F _2, it is possible to obtain a braking force requested by the driver (the total braking force) F ₀ in a stable manner.

In the present invention, the braking force (total braking force) F ₀ required by the driver is predicted based on the acceleration of the stroke (or the acceleration of the pedaling force) detected by the existing stroke sensor 15 (or the pedaling force sensor). Since the hydraulic pressure P required for the hydraulic brake 5 is obtained from the predicted braking force F _0, the brake squeal detecting means for detecting the brake squeal becomes unnecessary, and the cooperative brake control device 18 is reduced in cost and weight. be able to. Incidentally, when the hydraulic pressure P determined is less than the minimum pressure P _min, along with increasing the hydraulic braking force F ₂ by increasing the hydraulic pressure P in the above minimum fluid pressure P _min, the hydraulic braking force F ₂ control only increase reduces the regenerative braking force F ₁ is made.

Furthermore. According to the present invention, after the braking force F ₀ for requesting the driver cooperatively controls regenerative braking 4 and the hydraulic brake 5 is obtained, if the braking force F ₀ is increased, first regenerative braking force since you increase the F _1, it is possible to improve the fuel efficiency by effectively recovering kinetic energy as electric energy. On the other hand, when the braking force F ₀ required by the driver is obtained by cooperatively controlling the regenerative brake 4 and the hydraulic brake 5 and then the braking force F ₀ decreases, first the hydraulic brake 5 Is reduced to the minimum hydraulic pressure P _min to reduce the hydraulic braking force F ₂ and then the regenerative braking force F ₁ is decreased. Therefore, the regenerative braking force F ₁ is used for as long as possible. More kinetic energy can be recovered as electrical energy. In addition, since the hydraulic pressure P of the hydraulic brake 5 is kept at the minimum hydraulic pressure _Pmin , the driver's uncomfortable feeling when the regenerative braking is terminated due to a decrease in the vehicle speed can be eliminated.

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Front wheel 4 Regenerative brake 5 Hydraulic brake 6 Motor controller 7 Accelerator pedal 8 Accelerator position sensor 9 Brake pedal 12 Rear wheel 13 Brake device 13a Brake disk 13b Brake pad 14 Hydraulic control unit 15 Stroke sensor 18 Cooperative brake control device

Claims (4)

In a cooperative brake control device for a vehicle that obtains a braking force requested by a driver by cooperatively controlling a hydraulic brake that generates a hydraulic braking force and a regenerative brake that generates a regenerative braking force,
Actuates the liquid pressure brake fluid pressure on the minimum fluid pressure or if squeaking of the hydraulic brake sets a minimum pressure is the lowest value of the hydraulic pressure is not generated, using the hydraulic brake ,
The maximum regenerative braking force of the regenerative brake is set, the shortage of the maximum regenerative braking force with respect to the braking force requested by the driver is compensated by the hydraulic braking force, and the hydraulic pressure that generates the hydraulic braking force is the minimum hydraulic pressure. If not, the hydraulic pressure is increased above the minimum hydraulic pressure to increase the hydraulic braking force, and the regenerative braking force is decreased by the increase of the hydraulic braking force. apparatus.
A stroke sensor for detecting a stroke of the brake pedal or a pedal force sensor for detecting a pedal force applied to the brake pedal is provided, and the driver is based on the acceleration of the stroke detected by the stroke sensor or the acceleration of the pedal force detected by the pedal force sensor. The cooperative braking control device for a vehicle according to claim 1, wherein the braking force required by the vehicle is predicted .
After the braking force requested by the driver is obtained by cooperatively controlling the hydraulic brake and the regenerative brake, when the braking force requested by the driver is increased, the regenerative braking force is first increased, and then The cooperative brake control device for a vehicle according to claim 1 or 2, wherein the hydraulic braking force is increased .
After the braking force requested by the driver is obtained by cooperatively controlling the hydraulic brake and the regenerative brake, when the braking force requested by the driver decreases, the hydraulic pressure of the hydraulic brake is first set to the lowest hydraulic pressure. The cooperative brake control device for a vehicle according to any one of claims 1 to 3, wherein the hydraulic braking force is reduced by reducing the pressure to a pressure, and then the regenerative braking force is reduced .

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