JP5653067B2 - Brake slope support brake device for vehicle and control method thereof - Google Patents

Description

  The present invention relates to a vehicle slope start assist brake device and a control method thereof, and more particularly, to a motorcycle slope start assist brake device and a control method thereof.

  In passenger cars and motorcycles, a brake device to which a function for supporting starting on a slope is added is known. For example, Patent Literature 1 discloses a motorcycle brake device that continuously maintains a stopped state in response to a driver's request when a motorcycle is temporarily stopped, and allows a driver to perform both-hand work. Yes. This brake device is a wheel cylinder and a master cylinder provided in the anti-skid brake hydraulic unit when the switch means is on when the motorcycle brake device is operated by a brake operation and the motorcycle is stopped. Each open / close valve that disconnects the reservoir and the reservoir is switched to the closed state. Thus, the driver can automatically maintain the motorcycle in a stopped state by operating the switch means.

Patent Document 2 discloses a device for preventing backward rolling movement of a vehicle existing on a slope. In this device, the vehicle includes a backward rolling movement detecting means, and when backward rolling movement of the vehicle is detected, In order to suppress the backward rolling movement of the vehicle, the brake pressure of the rear wheels is increased without intervention of the driver.
JP 2006-315663 A JP 2000-108861 A

  The brake device of Patent Document 1 is inconvenient because it requires a driver to operate a switch in order to maintain a braking force on a slope or the like. Moreover, since the system of Patent Document 1 simply holds the hydraulic pressure at the time of operating the switch as it is, if the braking force is insufficient, the driver needs to additionally perform a braking operation. Further, since the hydraulic pressure at the time of operating the switch is merely maintained as it is, the vehicle behavior at the start may be increased depending on the brake distribution between the front wheels and the rear wheels.

  In the brake device of patent document 2, since the backward rolling movement is detected and the brake pressure is automatically raised, the problem of patent document 1 is partially solved. However, since the brake device of Patent Document 2 does not change the brake distribution when the braking force is maintained, the vehicle behavior at the start may still increase.

  Therefore, the present invention provides a brake device that maintains a braking force necessary to maintain a stopped state on a slope or the like without intervention of a driver and distributes a brake so that the vehicle can start smoothly. For the purpose.

  According to one embodiment of the present invention, a method for controlling the braking force of a vehicle while the vehicle is stopped is provided. The method includes (a) detecting a stop of the vehicle, (b) detecting a brake input release by the driver, and (c) calculating a total braking force of the vehicle when the driver releases the brake input. (D) calculating a braking force required for maintaining the vehicle stop; (e) determining whether the vehicle stop can be maintained with the calculated total braking force; and (f) measured. And increasing the total braking force of the vehicle when it is determined that the vehicle cannot be stopped with the total braking force.

In one embodiment, increasing the total braking force of the vehicle in step (f) increases the braking force of both the front and rear wheels of the vehicle.
In one embodiment, increasing the total braking force of the vehicle in step (f) increases the braking force of only one of the front or rear wheels of the vehicle.

  In one embodiment, the method further includes: (g) when it is determined that the stop of the vehicle can be maintained with the measured total brake force, the total brake force of the vehicle is greater than or equal to the total brake force required to maintain the stop of the vehicle. The distribution of the brake pressure distribution of each wheel is changed.

  In one embodiment, the method further comprises the step of (h) detecting the slope of the road surface on which the vehicle is stopped, wherein the road surface is detected to be uphill or flat in the detection in step (h). In step (g), the rear wheel braking force is distributed so as to be greater than the front wheel braking force.

In one embodiment, the method further comprises the step of (h) detecting the slope of the road surface on which the vehicle is stopped, and when detecting in step (h) that the road surface is downhill. In step (g), the braking force of the front wheels is distributed so as to be larger than the braking force of the rear wheels.
In one embodiment, the braking force is distributed in step (g) so that the braking force on the rear wheel side is substantially 100% and the braking force on the front wheel side is substantially 0%.

  According to the present invention, an apparatus for controlling a braking force of a vehicle while the vehicle is stopped is provided. The apparatus calculates (a) means for detecting stop of the vehicle, (b) means for detecting release of brake input by the driver, and (c) calculates the total braking force of the vehicle when the brake input is released by the driver. Means, (d) means for calculating the braking force required for maintaining the vehicle stop, (e) means for determining whether the vehicle stop can be maintained with the calculated total braking force, and (f) measured. And a means for increasing the total braking force of the vehicle when it is determined that the vehicle cannot be stopped with the total braking force. In one embodiment, the means (a) is realized by an arbitrary detector such as a radar sensor, a wheel speed sensor, and an acceleration sensor, and an ECU. In one embodiment, the means (b) is realized by a hydraulic pressure sensor or a brake lever switch 101 and a brake pedal switch 201a. In one embodiment, the means (c) is realized by, for example, a hydraulic pressure sensor and an electronic control unit ECU. In one embodiment, the means (d) is realized by, for example, a gradient sensor, a weight sensor, an ECU, or the like. In one embodiment, the means (e) is realized by an ECU or the like. In one embodiment, the means (f) is realized by, for example, a brake hydraulic unit including an electromagnetic valve and a pump, an ECU, and the like.

According to one embodiment, in the apparatus, the increase in the total braking force of the vehicle in means (f) increases the braking force of both the front and rear wheels of the vehicle.
According to one embodiment, in the device, the increase in the total braking force of the vehicle in means (f) increases the braking force of only one of the front or rear wheels of the vehicle.

  According to one embodiment, the apparatus further comprises: (g) a total brake force required for maintaining the vehicle stop when the vehicle total stop force is determined to be maintained with the measured total brake force. Means for changing the distribution of brake pressure of each wheel while maintaining the force or more. The means (g) is realized by, for example, a brake fluid pressure unit including an electromagnetic valve and a pump, an ECU, and the like.

  According to an embodiment, the apparatus further includes (h) means for detecting a slope of the road surface on which the vehicle is stopped, and it is detected in the detection in the means (h) that the road surface is uphill or flat. When this is done, the means (g) distributes the braking force of the rear wheels to be greater than the braking force of the front wheels. The means (h) is realized by, for example, a gradient sensor and an ECU.

  According to an embodiment, the apparatus further includes (h) means for detecting a slope of the road surface on which the vehicle is stopped, and it is detected in the detection in the means (h) that the road surface is a downhill. Sometimes, the means (g) distributes the braking force of the front wheels to be greater than the braking force of the rear wheels.

  According to one embodiment, in this device, the distribution of the braking force in the means (g) is such that the braking force on the rear wheel side is substantially 100% and the braking force on the front wheel side is substantially 0%. Be distributed as follows.

It is a figure which shows one Embodiment of the brake fluid pressure unit of a brake device. It is a block diagram which shows the structure of a brake device. It is a flowchart of the brake control by one Embodiment of this invention. It is a flowchart of the brake control by one Embodiment of this invention.

An embodiment in which a brake control device of the present invention is applied to a motorcycle will be described with reference to the drawings.
FIG. 1 shows a hydraulic circuit of a brake control device according to an embodiment of the present invention. This hydraulic circuit includes a front wheel hydraulic circuit 100, a rear wheel hydraulic circuit 200, and a DC motor 300 that drives each hydraulic pump of the front wheel hydraulic circuit 100 and the rear wheel hydraulic circuit 200. .

  First, the configuration of the front wheel hydraulic circuit 100 will be described. The front wheel hydraulic circuit 100 includes a brake lever 101 that is operated by the driver's right hand, a front wheel side master cylinder 103 that is pressurized when the brake lever 101 is operated, and a front wheel side that is connected to the front wheel side master cylinder 103. A master cylinder reservoir 105, a front wheel side switching valve 107 connected to the front wheel side master cylinder 103 via a conduit 104, and a front wheel side high pressure intake valve 109 connected to the front wheel side master cylinder 103 via a conduit 104. With. A filter is provided at each of the connection portion between the pipe line 104 and the front wheel side switching valve 107 and the connection portion between the pipe line 104 and the front wheel side high pressure suction valve 109. Further, a pressure sensor 111 is provided in the pipe line 104, and the pressure sensor 111 detects a pressure between the front wheel side master cylinder 103, the front wheel side switching valve 107, and the front wheel side high pressure intake valve 109, and an electronic device described later. It transmits to control unit ECU400.

  Further, the front wheel side first charging valve (inlet valve) 113 a is connected to the front wheel side switching valve 107 via a pipe line 106. A filter is also provided at a connection portion between each of the front wheel side switching valve 107 and the front wheel side first charging valve 113 a and the pipe line 106. The front wheel side first charging valve 113a is connected to the front wheel side first caliper 115a via a pipe line 114a.

  On the other hand, the front wheel side second charging valve 113 b is directly connected to the pipe line 104. A filter is also provided at a connection portion between the front wheel side second charging valve 113 b and the pipe line 104. The front wheel side second charging valve 113b is connected to the front wheel side second caliper 115b via a conduit 114b.

  The brake control device of the present invention is connected to a front wheel brake operated by a front wheel hydraulic circuit 100. The front wheel brake includes a front wheel first brake including a front wheel side first caliper 115a and a front wheel second brake including a front wheel side second caliper 115b.

  The front wheel side first caliper 115a is connected to the front wheel side first charging valve 113a via the conduit 114a as described above. Further, the front wheel side second caliper 115b is connected to the front wheel side second charging valve 113b via the conduit 114b as described above.

  On the other hand, the discharge side of the front wheel side hydraulic pump 119 is connected to the pipe line 106 through a throttle. The suction side of the front wheel side hydraulic pump 119 is connected to the pipe line 120 through a filter. The front wheel hydraulic pump 119 is driven by the DC motor 300. Further, one end of a front wheel side first check valve (check valve) 121 is connected to the pipe line 120. Further, a discharge port of a front wheel side high pressure suction valve 109 is connected to the pipe line 120. The other end of the front wheel side first check valve 121 is connected to the pipe line 122. The front wheel side first check valve 121 is disposed so as to prevent a backflow from the pipe 120 to the pipe 122.

  An inflow end of a front wheel side first relaxation valve (outlet valve) 123a is connected to the front wheel side first caliper 115a via a pipe line 114a. The outflow port of the front wheel side first relaxation valve 123 a is connected to the pipe line 122. Further, a filter is provided at a connection portion between the inflow port of the front wheel side first relaxation valve 123a and the pipe line 114a. A pressure sensor 127a is provided in the pipe line 114a. The pressure sensor 127a measures the pressure in the pipe line 114a and transmits a pressure signal to the ECU 400.

  Further, the front wheel side second caliper 115b is connected to the inflow port of the front wheel side second loosening valve 123b via a pipe line 114b. The outflow port of the front wheel side second release valve 123 b is connected to the pipe line 122. Further, a filter is provided at a connection portion between the inflow port of the front wheel side second relaxation valve 123b and the pipe line 114b. A pressure sensor 127b is provided in the pipe line 114b, and the pressure sensor 127b measures the pressure in the pipe line 114b and transmits a pressure signal to the ECU 400. In the present invention, the pressure sensor 127b is not necessarily present.

  Next, the configuration of the rear wheel hydraulic circuit 200 will be described with reference to FIG. The rear wheel hydraulic circuit 200 is connected to a brake pedal 201 that is operated with the right foot of the driver, a rear wheel master cylinder 203 that is pressurized when the brake pedal 201 is operated, and a rear wheel master cylinder 203. A rear wheel side master cylinder reservoir 205, a rear wheel side switching valve 207 connected to the rear wheel side master cylinder 203 via the pipe line 204, and a rear wheel side master cylinder 203 connected to the pipe line 204. And a rear wheel side high pressure intake valve 209. A filter is provided at each of the connection portion between the pipe line 204 and the rear wheel side switching valve 207 and the connection portion between the pipe line 204 and the rear wheel side high pressure suction valve 209. Further, a pressure sensor 211 is provided in the pipe line 204, and the pressure sensor 211 detects the pressure between the rear wheel side master cylinder 203 and the rear wheel side switching valve 207 and the rear wheel side high pressure intake valve 209, It transmits to ECU400.

  Further, the rear wheel side containment valve 213 is connected to the rear wheel side switching valve 207 via a pipe line 206. Filters are also provided at the connection portions between the rear wheel side switching valve 207 and the rear wheel side insertion valve 213 and the pipe line 206, respectively. The rear wheel side containment valve 213 is connected to the rear wheel caliper 215 via the pipe line 214. The rear wheel brake includes a rear wheel caliper 215. The rear wheel caliper 215 is connected to the rear wheel side valve 213 via the conduit 214 as described above.

  On the other hand, the discharge side of the rear wheel hydraulic pump 219 is connected to the pipe line 206 via a throttle. The suction side of the rear wheel side hydraulic pump 219 is connected to the pipeline 220 through a filter. The rear wheel hydraulic pump 219 is driven by the DC motor 300. In addition, one end of a rear wheel check valve 221 is connected to the pipe line 220. Further, a discharge port of a rear wheel side high pressure suction valve 209 is connected to the pipe line 220. The other end of the rear wheel check valve 221 is connected to the pipe line 222. The rear wheel side check valve 221 is arranged so as to prevent a backflow from the pipe line 220 to the pipe line 222.

  Further, the discharge port of the rear wheel side relaxation valve 223 is connected to the pipe line 222. Further, a rear wheel side reservoir (accumulator) 225 is connected to the pipe line 222 between the rear wheel side check valve 221 and the rear wheel side relaxation valve 223.

  The rear wheel caliper 215 is connected to the inflow port of the rear wheel side loosening valve 223 via the pipe line 214. The outflow port of the rear wheel side relaxation valve 223 is connected to the pipe line 222. Further, a filter is provided at the outflow port of the rear wheel side relaxation valve 223, the pipe line 214, and the connection portion. A pressure sensor 227 is provided in the pipe line 214, and the pressure sensor 227 measures the pressure in the pipe line 214 and transmits a pressure signal to the ECU 400.

  The hydraulic circuit shown in FIG. 1 is controlled by an electronic control unit (ECU) 400 shown in the block diagram of FIG. The ECU 400 is connected to a brake lever switch 101a provided on the brake lever 101, pressure sensors 111 and 127a, and a front wheel speed sensor 129 that detects the front wheel rotation speed. The brake lever switch 101a transmits an operation signal of the brake lever 101 to the ECU 400, the pressure sensors 111 and 127a transmit pressure signals in the pipe lines 104 and 114a to the ECU 400, respectively, and the front wheel speed sensor 129 rotates the front wheel. A speed signal is transmitted to ECU 400. Further, the ECU 400 is connected to a brake pedal switch 201a provided on the brake pedal 201, pressure sensors 211 and 227, and a rear wheel speed sensor 229 that detects a rear wheel rotation speed. The brake pedal switch 201 transmits an operation signal of the brake pedal 201 to the ECU 400, the pressure sensors 211 and 227 transmit the pressure signals in the pipe lines 204 and 214 to the ECU 400, respectively, and the rear wheel speed sensor 229 Is sent to ECU 400. If necessary, the EC 400 is connected to various sensors such as a radar sensor, an acceleration sensor, and a gradient sensor 302.

  In addition, the ECU 400 performs the DC motor 300, the front wheel side switching valve 107, the front wheel side high pressure intake valve 109, the front wheel side first charging valve 113a, the front wheel side second in accordance with predetermined conditions based on the operation signal, the pressure signal, and the speed signal. The intake valve 113b, the front wheel side first release valve 123a, and the front wheel side second release valve 123b are operated. Further, the ECU 400, based on the operation signal, the pressure signal, and the speed signal, in accordance with predetermined conditions, the rear wheel side switching valve 207, the rear wheel side high pressure suction valve 209, the rear wheel side intake valve 213, and the rear wheel side relaxation valve 223. , Each of the. Each of the valves is an electromagnetic valve having a solenoid, and the open / close state is switched by being energized by the ECU 400.

  Further, during braking, when the ECU 400 receives a rotational speed signal from the front wheel speed sensor 129 or the rear wheel speed sensor 229 and detects the lock of the wheel, the ECU 400 operates the anti-brake lock system (ABS), Each hydraulic pump is operated, each valve is opened and closed, and the braking force is controlled to prevent the wheels from being locked.

  In the brake device including the hydraulic circuit shown in FIG. 1, the braking force distribution is changed by changing the braking force of the front wheels and the rear wheels without the operation of the driver by operating the hydraulic pump and various valves. be able to. Refer to International Publication No. 2008/050744 for specific operations of the hydraulic pump and the solenoid valve when changing the braking force distribution.

  The brake device of the present invention has a slope start support control (hill hold control, HHC) function described below in one embodiment. Hereinafter, the slope start support control according to the embodiment of the present invention will be described with reference to the flowcharts shown in FIGS. 3 and 4.

  In step S10, the HHC control calculation is started. The condition for starting the HHC control calculation can be an arbitrary condition. For example, ignition on can be set as a start condition.

  Next, in step S12, it is determined whether or not the vehicle is stopped. The determination of whether the vehicle is stopped can be made using any conventional technique. For example, the determination can be made using a radar sensor, a wheel speed sensor, an acceleration sensor, or the like. Calculation of vehicle speed using these sensors is within the scope of the prior art and will not be described here. If the vehicle is not stopped, the process returns to step S10 again.

  If it is determined in step S12 that the vehicle is stopped, it is next determined in step S14 whether the vehicle is on a slope. This determination can be made by measuring the gradient using the gradient sensor 302 or the like and comparing the measured gradient with a predetermined gradient. If it is determined in step S14 that the vehicle is not on a slope, the process returns to step S12. In the present invention, step S14 is not necessarily present. Therefore, the gradient sensor 302 may be omitted.

  If it is determined in step S14 that the vehicle is on a slope, it is next determined in step S16 whether or not the brake input has been released by the driver. Release of the brake input by the driver may be determined by measuring the hydraulic pressure of the master cylinders 103 and 203 by the hydraulic pressure sensors 111 and 211, and regarding the decrease in the hydraulic pressure of the master cylinders 103 and 203 as release of the brake input by the driver. it can. Alternatively, the release of the brake input by the driver may be regarded as the release of the brake input by the driver by measuring the hydraulic pressure of the wheel cylinder by the hydraulic pressure sensors 127a, 127b, and 227, and the decrease in the hydraulic pressure of the wheel cylinder. Alternatively, the release of the brake input by the driver may be determined using the brake lever switch 101a and the brake pedal switch 201a.

  If it is determined in step S16 that the brake input by the driver has not been released, the process returns to step S12. If it is determined in step S16 that the brake input by the driving vehicle has been released, the process proceeds to step S18, and the HHC pressure calculation described in more detail in FIG. 4 is started.

FIG. 4 shows a flowchart of the HHC pressure calculation.
First, in step S20, it is determined whether or not to continue HHC. Whether or not to continue HHC can be performed by a conventionally known method. For example, the driver's intention to start can be determined from the engine speed, wheel speed, etc., and it can be determined to continue HHC when there is no intention to start (see, for example, Patent Document 1).

  If it is determined in step S20 that the HHC is not continued, the brake pressure by the HHC is released in step S22. Specifically, the switching valves 107 and 207 are released to release the hydraulic pressure of the wheel cylinder.

  If it is determined in step S20 that the HHC is to be continued, the brake force in the system is measured in step S24. Specifically, the hydraulic pressures of the wheel cylinders are measured by the hydraulic pressure sensors 127a, 127b, and 227, and converted into braking force. Since it is an extremely short time from the release of the brake input by the driver in step S16 to the calculation of the brake force of the vehicle in step S24, the brake force of the vehicle when the brake input is released by the driver is substantially calculated in step S24. The When calculating the total braking force of the vehicle from the pressure sensor signal on the wheel cylinder side, calculate the total braking force with higher accuracy than calculating the total braking force of the vehicle using the hydraulic pressure sensor on the master cylinder side. be able to. This is because the liquid pressure is measured near the calipers 115a, 115b, and 215, so that errors due to liquid loss are reduced. If the error is allowed, the total braking force of the vehicle may be calculated using a hydraulic pressure sensor on the master cylinder side.

  Next, in step S26, a brake force and a brake pressure necessary for maintaining the stop of the vehicle are calculated. The required braking force and braking pressure can be calculated from the weight of the vehicle body, the inclination angle, and the like.

  In step S28, it is determined whether or not the vehicle can be stopped by the braking force in the system measured in step S24. Specifically, the in-system braking force measured in step S24 is compared with the braking force required for maintaining the vehicle stop calculated in step S26.

  If it is determined in step S28 that the vehicle cannot be stopped, the brake pressure in the system is automatically increased without intervention of the driver in step S30. Specifically, the high-pressure intake valve 109 is opened and the hydraulic pump 300 is driven, and the hydraulic pressure is adjusted by the switching valve 107 to increase the wheel cylinder. At this time, in order to increase the pressure as quickly as possible, it is preferable to increase the pressure on the wheel cylinders on the front and rear wheels. For example, in the system configuration of the embodiment shown in FIG. 1, the high-pressure intake valves 109 and 209 are opened, the hydraulic pump 300 is driven, and the hydraulic pressure is adjusted by the switching valves 107 and 207 to adjust the front wheel side and the rear wheel side. Increase the pressure of the wheel cylinder.

  Further, when the difference between the total braking force in the system at the time of releasing the brake input by the driver calculated in step S24 and the braking force required for maintaining the vehicle stop calculated in step S26 is a predetermined value or more, It is desirable to increase the pressure on both the front and rear wheels. If it does in this way, the brake force required for vehicle maintenance can be performed quickly after the driver releases the brake.

  On the other hand, when the above-described difference in brake force is smaller than a predetermined value, only one of the front wheels or the rear wheels may be increased in pressure. In this way, it is possible to quickly change the brake pressure distribution of the front and rear wheels in step S32 described later. Note that the predetermined value related to the difference in braking force can be appropriately changed according to the vehicle weight, the gradient of the slope, and the like.

When the wheel cylinder is increased in step S30, the process returns to step S20.
On the other hand, if it is determined in step S30 that the vehicle stop can be maintained, in step S32 the front wheel side and the rear wheel side while maintaining the total brake force of the entire vehicle at or above the total brake force required for maintaining the vehicle stop. Change the brake force distribution. In one embodiment, the brake distribution is performed such that the brake force on the rear wheel side is greater than the brake force on the front wheel side while maintaining the total brake force of the vehicle at or above the total brake force calculated in step S26. . For example, the distribution is performed such that the braking force on the front wheel side is substantially 0% and the braking force on the rear wheel side is substantially 100%. By increasing the brake distribution on the rear wheel side, the behavior change at the time of start is reduced and the vehicle can start smoothly. Thus, the brake distribution in which the braking force on the rear wheel side is larger than the braking force on the front wheel side is particularly advantageous when the vehicle is on an uphill or a flat road surface.

  In another embodiment, when the vehicle is on a downhill, the brake distribution is such that the braking force on the front wheel side is greater than the braking force on the rear wheel side while maintaining the total braking force measured in step S24. It may be distributed.

  The specific operation of the hydraulic pressure unit valves and pumps when changing the brake pressure distribution varies depending on the hydraulic pressure unit. For example, in the system configuration of the embodiment shown in FIG. 1, the braking force on the front wheel side is increased. In order to make this happen, the high pressure suction valve 109 is opened, the front wheel pump 119 is operated by the DC motor 300, and the hydraulic pressure is adjusted by the switching valve 107 to increase the pressure of the front wheel wheel cylinder.

  For example, in the hydraulic unit shown in FIG. 1, when the braking force of the rear wheel is increased, the high-pressure intake valve 209 is opened, the rear motor 219 is operated by the DC motor 300, and the hydraulic pressure is adjusted by the switching valve 207. Then, the wheel cylinder on the rear wheel side is increased in pressure.

  Another brake circuit and control method is described in WO 2008/050744. The brake force can be distributed by the brake circuit and the control method disclosed in International Publication No. 2008/050744.

If the distribution of the braking force is changed in step S32, the process returns to step S20 again.
As described above, according to an embodiment of the present invention, when the motorcycle stops on a hill, even if the driver releases the brake lever or the like, no additional operation by the driver is required. The braking force necessary for reliably stopping the vehicle can be maintained, and the distribution of the braking force at the time of stopping can be arbitrarily changed so that the vehicle can start smoothly.

Claims (8)

A method for controlling a braking force of a vehicle while the vehicle is stopped,
(A) detecting the stop of the vehicle;
(B) detecting a brake input release by the driver;
(C) calculating the total braking force of the vehicle when the driver releases the brake input;
(D) calculating the braking force required to maintain the vehicle stopped;
(E) determining whether the vehicle stop can be maintained with the calculated total braking force;
(F) When it is determined that the stop of the vehicle cannot be maintained with the measured total braking force, the total braking force of the vehicle when the driver releases the brake input, and the braking force necessary for maintaining the stop of the vehicle; If the difference is greater than or equal to a predetermined value, the total braking force of the vehicle is increased by increasing both the front and rear wheels. If the difference in braking force is smaller than the predetermined value, either the front wheel or the rear wheel is increased. Increasing the total braking force of the vehicle by increasing only the pressure,
(G) When it is determined that the stop of the vehicle can be maintained with the measured total brake force, the brake pressure of each wheel is maintained while maintaining the total brake force of the vehicle at or above the total brake force necessary for maintaining the stop of the vehicle. Changing the distribution of
Having a method. The method according to claim 1, further comprising: (h) detecting a slope of a road surface on which the vehicle is stopped,
When it is detected in step (h) that the road surface is uphill or flat, in step (g), the braking force of the rear wheels is distributed so as to be greater than the braking force of the front wheels. The way. The method according to claim 1, further comprising: (h) detecting a slope of a road surface on which the vehicle is stopped,
In the detection in step (h), when it is detected that the road surface is downhill, in step (g), the braking force of the front wheels is distributed so as to be larger than the braking force of the rear wheels. Method. The method of claim 2 , comprising:
The method of distributing the braking force in the step (g) is such that the braking force on the rear wheel side is substantially 100% and the braking force on the front wheel side is substantially 0%. A device for controlling the braking force of a vehicle while the vehicle is stopped,
(A) means for detecting stop of the vehicle;
(B) means for detecting brake input release by the driver;
(C) means for calculating the total braking force of the vehicle when the brake input is released by the driver;
(D) means for calculating the braking force required to maintain the vehicle stopped;
(E) means for determining whether the stop of the vehicle can be maintained with the calculated total braking force;
(F) When it is determined that the stop of the vehicle cannot be maintained with the measured total braking force, the total braking force of the vehicle when the driver releases the brake input, and the braking force necessary for maintaining the stop of the vehicle; If the difference is greater than or equal to a predetermined value, the total braking force of the vehicle is increased by increasing both the front and rear wheels. If the difference in braking force is smaller than the predetermined value, either the front wheel or the rear wheel is increased. Means for increasing the total braking force of the vehicle by increasing only the pressure ,
(G) When it is determined that the stop of the vehicle can be maintained with the measured total brake force, the brake pressure of each wheel is maintained while maintaining the total brake force of the vehicle at or above the total brake force necessary for maintaining the stop of the vehicle. A means of changing the distribution of
Having a device. The apparatus according to claim 5 , further comprising: (h) means for detecting a slope of a road surface on which the vehicle is stopped,
In the detection by the means (h), when it is detected that the road surface is uphill or flat, the means (g) distributes the braking force of the rear wheels to be larger than the braking force of the front wheels. Equipment. The apparatus according to claim 5 , further comprising: (h) means for detecting a slope of a road surface on which the vehicle is stopped,
In the detection in the means (h), when it is detected that the road surface is a downhill, in the means (g), the braking force of the front wheels is distributed so as to be larger than the braking force of the rear wheels. apparatus. The method of claim 6 , comprising:
The distribution of the braking force in the means (g) is such that the braking force on the rear wheel side is substantially 100% and the braking force on the front wheel side is substantially 0%.

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