Brake control device and vehicle braking method

Abstract

This prevents sudden acceleration when the electric parking brake is thawed. [Solution] The brake control device 100 is a control device for a vehicle 1 in which at least the rear wheels 3 are drive wheels, and is equipped with an electric parking brake 8 that applies braking force to the rear wheels 3 to fix the vehicle 1 when parked. The brake control device 100 includes a starting intention detection unit 101, a freezing determination unit 102, and a brake control unit 103. The starting intention detection unit 101 detects the driver's intention to start the vehicle 1. If the freezing determination unit 102 determines that the electric parking brake 8 is frozen, it performs starting control that applies braking force to the front wheels 2 or the front wheels 2 and rear wheels 3 of the vehicle 1.

Description

Technical Field

[0001] The present invention relates to a brake control device and a braking method for a vehicle.

Background Art

[0002] Vehicles equipped with an electric parking brake, which is an electrified version of a manual parking brake, are becoming widespread. The electric parking brake is prone to freezing in cold regions with low temperatures. For example, Patent Document 1 describes an electric brake device provided with freezing prevention energization means that controls to start energizing a drive source when detecting the temperature just before freezing of an electric brake device in which a temperature sensor is set. Thereby, freezing of the electric parking brake can be prevented in advance.

[0003] On the other hand, in a vehicle that does not have such freezing prevention energization means and in which the electric parking brake has frozen, the driver depresses the accelerator pedal deeply to apply strong torque to the wheels, thereby releasing the freezing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the electric brake device described in Patent Document 1, there is a problem that the power consumption of the vehicle increases due to energization for freezing prevention. Further, when the driver depresses the accelerator pedal deeply to release the freezing, there is a risk that the vehicle will suddenly accelerate when the freezing is released.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a brake control device and a braking method for a vehicle that can prevent sudden acceleration when releasing the freezing of an electric parking brake. [Means for solving the problem]

[0007] To achieve the above objective, the brake control device according to the present invention is a brake control device for a vehicle in which at least the rear wheels are drive wheels, and is equipped with an electric parking brake that applies braking force to the rear wheels to fix the vehicle in place when parked. The processor of this brake control device detects the driver's intention to start the vehicle, and when an intention to start is detected, it determines whether or not the electric parking brake is frozen, and when it is determined that the electric parking brake is frozen, it performs a starting control that applies braking force to the front wheels or the front and rear wheels of the vehicle. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent sudden acceleration when the electric parking brake is thawed. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram illustrating the overall configuration of a vehicle equipped with a brake control device according to the embodiment. [Figure 2] This is a block diagram showing an example of the hardware configuration of a brake control device according to an embodiment. [Figure 3] This is a flowchart of the braking control process during starting according to the embodiment. [Figure 4] This is a flowchart of the braking control process at startup according to Modification 1. [Modes for carrying out the invention]

[0010] A brake control device 100 and a vehicle control method according to an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same or equivalent parts are denoted by the same reference numerals.

[0011] (Embodiment) Figure 1 is a schematic diagram illustrating the overall configuration of a vehicle 1 equipped with the brake control device 100 according to this embodiment. This vehicle 1 is a rear-wheel drive type four-wheeled vehicle, and in Figure 1, the upper wheels are the left and right front wheels 2L and 2R, and the lower wheels are the left and right rear wheels 3L and 3R, which are the drive wheels. Note that when the left and right front wheels 2L and 2R are not distinguished, they are also referred to as front wheels 2, and when the left and right rear wheels 3L and 3R are not distinguished, they are also referred to as rear wheels 3. Furthermore, in Figure 1, only the brake control device 100 and its related components are shown as the configuration of vehicle 1, and other general components of vehicle 1 are omitted.

[0012] First, let's describe the braking configuration of Vehicle 1. Vehicle 1 is equipped with the following braking components: hydraulic brakes 5L and 5R for the front wheels, hydraulic brakes 6L and 6R for the rear wheels, a brake actuator 7, an electric parking brake 8, and an electric parking brake controller (also referred to as EPB controller 9).

[0013] The front hydraulic brakes 5L and 5R are installed on the axles of the left and right front wheels 2L and 2R, respectively, and are equipped with calipers, brake discs, etc. (not shown). When the brake pedal is operated, or when hydraulic pressure is generated by the brake actuator 7 described later, the caliper pushes out the brake pads and presses them against the brake discs of the respective front wheels 2L and 2R. In this way, the front hydraulic brakes 5L and 5R can apply braking force to the front wheels 2L and 2R. In the following description, when the front hydraulic brakes 5L and 5R are not distinguished, they will also be referred to as the front hydraulic brake 5.

[0014] The rear hydraulic brakes 6L and 6R are installed on the axles of the left and right rear wheels 3L and 3R, respectively, and are equipped with calipers, brake discs, etc. (not shown). When the brake pedal is operated, or when hydraulic pressure is generated by the brake actuator 7 described later, the caliper pushes out the brake pads and presses them against the brake discs of the respective rear wheels 3L and 3R. In this way, the rear hydraulic brakes 6L and 6R can apply braking force to the rear wheels 3L and 3R. In the following description, when the rear hydraulic brakes 6L and 6R are not distinguished, they will also be referred to as rear hydraulic brake 6.

[0015] The brake actuator 7 operates the brake pads by individually supplying compressed brake fluid to the calipers of the front hydraulic brakes 5L, 5R and the rear hydraulic brakes 6L, 6R based on commands from the brake control device 100, thereby applying hydraulic pressure. This allows for precise individual control of the braking force applied by the front hydraulic brakes 5L, 5R to the front wheels 2L, 2R, and the braking force applied by the rear hydraulic brakes 6L, 6R to the rear wheels 3L, 3R.

[0016] The electric parking brake 8 is a braking system that applies braking force to the rear wheels 3 of the vehicle 1. The electric parking brake 8 includes a motor, gears, caliper, brake disc, etc. (not shown). The motor is driven in response to instructions from the EPB controller 9, and the driving force is transmitted to the brake pads of the caliper via the gears, pressing the brake pads against the brake discs of the rear wheels 3. In this way, the electric parking brake 8 can apply braking force to the rear wheels 3. The EPB controller 9 is an ECU that controls the operation of the electric parking brake 8. The EPB controller 9 may be located within the brake control device 100, which will be described later.

[0017] Note that the rear-wheel hydraulic brake 6 and the electric parking brake 8 may share components such as a caliper and a brake disk. That is, even for a brake having the same caliper, brake disk, etc., when the brake pad of the caliper is pressed against the brake disk by hydraulic pressure and a braking force is applied to the rear wheel 3, it is the rear-wheel hydraulic brake 6, and when the brake pad of the caliper is pressed against the brake disk by the driving force from the motor and a braking force is applied to the rear wheel 3, it is the electric parking brake 8.

[0018] The vehicle 1 further includes a mode selection switch 10, an accelerator position sensor 11, a tilt sensor 12, and wheel speed sensors 13L and 13R.

[0019] The mode selection switch 10 is provided on the vehicle interior console, dashboard, etc., and is a switch for the driver to select the operation mode of the vehicle 1. The operation mode of the vehicle is set to the operation mode selected by the mode selection switch 10. In the present embodiment, the mode selection switch 10 is a two-way selection type switch, and the driver can select either the cold region mode or the non-cold region mode by operating the mode selection switch 10 and set the operation mode of the vehicle 1. In a vehicle in which the operation mode is set to the cold region mode, when the intention to start the vehicle 1 is detected when the electric parking brake 8 is frozen, the front-wheel hydraulic brake 5 and the rear-wheel hydraulic brake 6 are actuated to perform start-up control to prevent the vehicle 1 from suddenly starting. On the other hand, in the vehicle 1 in which the operation mode is set to the non-cold region mode, such start-up control is not executed.

[0020] The accelerator position sensor 11 is a sensor that detects the degree of depression of the accelerator pedal of the vehicle 1. When the driver depresses the accelerator pedal, the accelerator position sensor 11 transmits a signal indicating the accelerator opening degree indicating the degree of depth to the brake control device 100. The accelerator position sensor 11 continuously detects the accelerator opening degree of the vehicle 1 at all times and outputs a signal indicating the detected accelerator opening degree to the brake control device 100.

[0021] The tilt sensor 12 is a sensor for detecting the tilt of the vehicle 1, and is, for example, an acceleration sensor, an inertial sensor, a G sensor, or the like. The tilt sensor 12 continuously detects the tilt of the vehicle 1 at all times, and outputs a signal indicating the magnitude of the detected tilt to the brake control device 100.

[0022] The wheel speed sensors 13L and 13R are respectively installed near the left and right rear wheels 3L and 3R, and are sensors for detecting the wheel speeds of the rear wheels 3L and 3R. The wheel speed sensors 13L and 13R continuously detect the wheel speeds of the rear wheels 3L and 3R at all times, and output signals indicating the detected wheel speeds to the brake control device 100. When the wheel speed sensors 13L and 13R are not distinguished, they are also denoted as the wheel speed sensor 13.

[0023] Next, the brake control device 100 according to the present embodiment will be described. The brake control device 100 is a control device such as an ECU that controls the front wheel hydraulic brake 5 and the rear wheel hydraulic brake 6 to apply braking force to the front wheels 2 and the rear wheels 3 to prevent sudden start when the electric parking brake 8 is frozen when the parked vehicle 1 attempts to start. An example of the hardware configuration of the brake control device 100 is shown in FIG. 2. In the example of FIG. 2, the brake control device 100 includes a processor 1011, a memory 1012, a storage 1013, and a communication interface 1014 that are connected to each other via a bus 1010.

[0024] The processor 1011 includes, for example, one or more CPUs (Central Processing Unit: central calculation device) and its peripheral circuits, and executes various arithmetic processes. The processor 1011 reads the control program stored in the storage 1013 into the memory 1012 and executes it. Note that the processor 1011 may further include arithmetic circuits such as a logical arithmetic unit and a numerical arithmetic unit.

[0025] Memory 1012 includes, for example, volatile semiconductor memory such as RAM (Random Access Memory) and functions as the work memory of processor 1011. Memory 1012 also temporarily stores control programs read by processor 1011 from storage 1013 and various data used in the processor 1011's arithmetic processing.

[0026] The storage 1013 includes, for example, non-volatile semiconductor memory such as EEPROM (Electrically Erasable and Programmable Read Only Memory) or flash memory. The storage 1013 stores control programs executed by the processor 1011 and various data used in the arithmetic processing of the processor 1011. For example, the storage 1013 stores data indicating thresholds for determining wheel speed, which are referenced in the brake control processing during starting described later, and data defining conversion formulas for calculating the hydraulic pressure applied to the front wheel hydraulic brake 5 from the accelerator opening.

[0027] The communication interface 1014 includes an interface circuit for connecting the brake control device 100 to an in-vehicle network compliant with standards such as CAN (Controller Area Network). The communication interface 1014 receives signals from the mode selection switch 10, accelerator position sensor 11, tilt sensor 12, wheel speed sensor 13, and other in-vehicle components (not shown) and passes them to the processor 1011.

[0028] Furthermore, the communication interface 1014 transmits control signals generated by the processor 1011 to the brake actuator 7 and the EPB controller 9. Based on the received control signals, the brake actuator 7 and the EPB controller 9 control the operation of the front hydraulic brake 5, the rear hydraulic brake 6, and the electric parking brake 8.

[0029] Next, the functions of the brake control device 100 will be described. For example, the brake control device 100 implements the functions shown in Figure 1 by having the processor 1011 execute a control program stored in the storage 1013. Specifically, the brake control device 100 implements the functions of the starting intention detection unit 101, the freezing determination unit 102, and the brake control unit 103.

[0030] The departure intention detection unit 101 estimates and detects the driver's intention to start the vehicle 1 based on the detection results from the accelerator position sensor 11 and other sources. Specifically, the departure intention detection unit 101 detects the driver's intention to start the vehicle 1 when the accelerator pedal is pressed while the shift lever of the parked vehicle 1 is switched to the drive range. However, the method of detecting the departure intention by the departure intention detection unit 101 is not limited to this, and various methods can be employed. For example, operations such as releasing the steering wheel lock, turning on the ignition, releasing the electric parking brake 8, or setting a destination in the car navigation system may be detected as the intention to start.

[0031] When the starting intention detection unit 101 detects the vehicle 1's intention to start, the freezing determination unit 102 determines whether the electric parking brake 8 is frozen based on the detection values ​​of the accelerator position sensor 11, the tilt sensor 12, and the wheel speed sensor 13. Here, freezing of the electric parking brake 8 means that the brake pads or brake discs of the electric parking brake 8 are frozen to such an extent that it interferes with the drive of the rear wheels 3.

[0032] Here, the method for determining freezing by the freezing determination unit 102 will be explained in detail. First, the freezing determination unit 102 estimates the driving force (additional driving force) applied to the vehicle 1 from the accelerator opening detected by the accelerator position sensor 11. The freezing determination unit 102 also estimates the driving force (required driving force) necessary for the vehicle 1 to start when the electric parking brake 8 is not frozen, from the degree of tilt of the vehicle 1 measured by the tilt sensor 12. The freezing determination unit 102 then determines that the electric parking brake 8 is frozen if the additional driving force is greater than or equal to the required driving force, and the wheel speed of at least one of the rear wheels 3L and 3R detected by the wheel speed sensor 13 is below a threshold. Otherwise, it determines that the electric parking brake 8 is not frozen. Note that the method for determining freezing by the freezing determination unit 102 is not limited to this, and the presence or absence of freezing of the electric parking brake 8 may be determined by other methods. For example, if the vehicle 1 is also equipped with an acceleration sensor, an outside temperature sensor, etc., the detection results of these sensors may also be taken into consideration when determining whether or not the electric parking brake 8 is frozen.

[0033] When the brake control unit 103 determines that the electric parking brake 8 is frozen, it controls the front hydraulic brakes 5 and rear hydraulic brakes 6 to apply braking force to the front wheels 2 and rear wheels 3, thereby performing starting control. At this time, the brake control unit 103 sequentially adjusts the braking force applied to the front wheels 2 and rear wheels 3 based on the degree to which the accelerator pedal is pressed (accelerator opening) and the wheel speed of the rear wheels 3. This makes it possible to prevent the vehicle 1 from suddenly accelerating due to the driver pressing the accelerator pedal too hard in an attempt to release the frozen electric parking brake 8. Details of the starting control by the brake control unit 103 will be described later.

[0034] Next, the operation of the starting brake control process performed by the brake control device 100 configured as described above will be explained using the flowchart in Figure 3. For example, in a parked vehicle 1, the driver performs an operation to release the electric parking brake 8, and the EPB controller 9 controls the electric parking brake 8 to be deactivated. Then, when the driver switches the shift lever to the drive range and presses the accelerator pedal, and this is detected by the accelerator position sensor 11, the starting intention detection unit 101 of the brake control device 100 determines that the driver has indicated an intention to start the vehicle 1, and the brake control device 100 starts the starting brake control process.

[0035] When the braking control process for starting begins, the brake control device 100 first determines whether the operating mode of the vehicle 1 is set to cold weather mode (step S11). If the operating mode is not set to cold weather mode (step S11; No), the braking control process for starting ends. Step S11 is optional, in which case the braking control process for starting may begin from step S12.

[0036] On the other hand, if the operating mode is set to cold weather mode (step S11; Yes), the freezing determination unit 102 determines whether or not the electric parking brake 8 is frozen based on the accelerator opening and the wheel speed of the rear wheels 3 (step S12). If it is determined that the electric parking brake 8 is not frozen (step S12; No), the possibility of the vehicle 1 suddenly accelerating is low, so the braking control process at the time of acceleration is terminated.

[0037] On the other hand, if it is determined that the electric parking brake 8 is frozen (step S12; Yes), the driver who wants to start vehicle 1 is expected to press the accelerator pedal harder than usual to release the frozen electric parking brake 8, which could cause vehicle 1 to suddenly accelerate. Therefore, the brake control unit 103 sends a control signal to the brake actuator 7 to control the hydraulic brake 5 for the front wheels, thereby applying braking force to the front wheels 2 based on the current accelerator opening (step S13).

[0038] Specifically, the brake control unit 103 calculates the hydraulic pressure of the front wheel hydraulic brake 5 using a predetermined formula, which is the amount obtained by subtracting a predetermined amount (0 to 0.1G) from the driving torque of the vehicle's drive source (engine or motor) estimated from the current accelerator opening, and applies this braking force to the front wheel 2. The brake actuator 7 then controls the brake actuator 7 to apply the calculated hydraulic pressure to the caliper of the front wheel hydraulic brake 5.

[0039] Next, the brake control unit 103 determines whether the wheel speed of at least one of the left and right rear wheels 3L and 3R is above a threshold (step S14). The threshold here should be a value that at a minimum confirms that the freezing of the electric parking brake 8 has been resolved and there is no impediment to the rotation of the rear wheels 3L and 3R, for example, 5 km / h.

[0040] If the wheel speeds of both rear wheels 3L and 3R are below the threshold (step S14; No), it is assumed that both the electric parking brakes 8 of the left and right rear wheels 3L and 3R are frozen, so the process returns to step S13, and braking force based on the current accelerator opening continues to be applied to the front wheels.

[0041] On the other hand, if the wheel speed of at least one of the rear wheels 3L and 3R is above a threshold (step S14; Yes), the brake control unit 103 determines whether the wheel speeds of both rear wheels 3L and 3R are above a threshold (step S15).

[0042] If at least one of the rear wheels 3L and 3R has a wheel speed less than the threshold (step S15; No), the electric parking brake 8 of the rear wheel whose wheel speed is above the threshold will defrost, but the electric parking brake 8 of the rear wheel 3 whose wheel speed is below the threshold will remain frozen. Therefore, if the electric parking brake 8 of the frozen rear wheel 3 is then defrosted and the vehicle 1 starts moving, there is a risk that the vehicle 1 will spin due to a large speed difference between rear wheel 3L and rear wheel 3R. For this reason, the brake control unit 103 sends a control signal to the brake actuator 7 to control the rear wheel hydraulic brake 6, thereby applying braking force only to the rear wheels 3L and 3R whose wheel speeds are determined to be above the threshold (step S16). Then, the process returns to step S15, and the determination of the wheel speed of the rear wheel 3 is repeated.

[0043] On the other hand, if the wheel speeds of both 3L and 3R are above the threshold (step S15; Yes), the freezing of the electric parking brake 8 is completely resolved and the vehicle 1 starts moving. In this case, the brake control unit 103 sends a control signal to the brake actuator 7 to control the front hydraulic brake 5 and the rear hydraulic brake 6, gradually reducing the braking force added in steps S13 and S16 (step S17). The brake control unit 103 may also reduce the braking force after the vehicle 1 reaches a normal speed (e.g., 10 km / h). This completes the process.

[0044] As described above, with the brake control device 100 according to this embodiment, when the driver's intention to start the vehicle 1 is detected by the starting intention detection unit 101, the freezing determination unit 102 determines whether or not the electric parking brake 8 is frozen, and if it is determined to be frozen, the brake control unit 103 performs starting control in which braking force is applied to the front wheels 2 or the front wheels 2 and rear wheels 3 of the vehicle 1. In other words, with the brake control device 100 according to this embodiment, when the driver presses the accelerator pedal deeply when starting to defrost the electric parking brake 8, braking force is applied to at least the front wheels 2, making it possible to prevent sudden acceleration when defrosting.

[0045] Furthermore, according to the brake control device 100 of this embodiment, in starting control, the brake control unit 103 applies braking force to the front wheels 2 based on the accelerator opening, which indicates the amount the accelerator pedal is pressed. This makes it possible to apply appropriate braking force to the front wheels 2 and more reliably prevent sudden acceleration.

[0046] Furthermore, according to the brake control device 100 of this embodiment, in starting control, if the wheel speed of one of the left and right rear wheels 3L and 3R is above a threshold and the wheel speed of the other wheel is below the threshold, the brake control unit 103 applies braking force to the rear wheel 3L and 3R whose wheel speed is above the threshold. This makes it possible to reduce the speed difference between the left and right rear wheels 3L and 3R, and makes it possible to prevent the vehicle 1 from spinning when the electric parking brake 8 is released from freezing.

[0047] Furthermore, according to the brake control device 100 of this embodiment, in starting control, the brake control unit 103 gradually reduces the applied braking force when the wheel speeds of both the left and right rear wheels 3L and 3R are above a threshold. This makes it possible to start the vehicle 1 smoothly after the freezing of the electric parking brake 8 has been undone.

[0048] Furthermore, according to the brake control device 100 of this embodiment, the brake control unit 103 executes starting control only when the operating mode of the vehicle 1 is set to a specific mode such as the cold weather mode. This makes it possible for the driver to set the operating mode so that starting brake control is not executed.

[0049] (Variation 1) In the above embodiment, it was assumed that vehicle 1 is a rear-wheel drive type four-wheel vehicle, but in the modified example 1, vehicle 1 is characterized by being a four-wheel drive vehicle.

[0050] The braking control process performed by the brake control device 100 in Modification 1 during starting will be explained using the flowchart in Figure 4. Steps that are substantially the same as those in the braking control process during starting in Embodiment 1 will be given the same step numbers, and explanations will be simplified or omitted as appropriate.

[0051] When the braking control process starts during acceleration, and the operating mode is cold weather mode (step S11; Yes), and it is determined that the electric parking brake is frozen (step S12; Yes), the brake control unit 103 cuts the driving force from the drive source (motor, engine) to the front wheels (step S125). For example, the brake control unit 103 can perform the process in step S125 by sending a signal to the ECU for motor control of the vehicle 1 (not shown) instructing it to cut the driving force to the front wheels 2. As a result, the vehicle 1 temporarily becomes a front-wheel drive vehicle, similar to Embodiment 1, and the brake control unit 103 can then perform the processes from step S13 onwards, similar to Embodiment 1.

[0052] Thus, with the brake control device 100 in the modified example 1, even if the vehicle 1 is a four-wheel drive vehicle, it is possible to prevent sudden acceleration when the electric parking brake 8 freezes, just as in the first embodiment.

[0053] (Other variations) This invention is not limited to the above embodiments or Modification 1, and various modifications and applications are possible. For example, parts of the above embodiments can be omitted or replaced, or arbitrary configurations can be added. Also, the hardware configuration, functional configuration, flowchart, etc. shown in the above embodiments are examples and can be changed as appropriate.

[0054] For example, in the above embodiment and Modification 1, in step S14 of the starting brake control process, a braking force based on the accelerator opening is applied to the front wheel 2, but a fixed braking force that does not depend on the accelerator opening may also be applied to the front wheel 2.

[0055] For example, in the above embodiment, an example was described in which the processor 1011 executes a control program to realize each function of the brake control device 100. However, the brake control device 100 may also be configured with dedicated hardware to realize each function.

[0056] Furthermore, the brake control device 100 can be configured to realize each function by distributing a control program for executing the operations of the above embodiment on a computer-readable recording medium such as a CD-ROM (Compact Disc Read-Only Memory), DVD (Digital Versatile Disc), MO (Magneto Optical Disc), or memory card, and installing the program on a computer. In cases where each function is realized through a division of labor between the OS (Operating System) and an application, or through cooperation between the OS and an application, only the parts other than the OS may be stored on the recording medium.

[0057] The present invention allows for various embodiments and modifications without departing from the broad spirit and scope of the invention. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of the invention. In other words, the scope of the invention is indicated by the claims, not by the embodiments. Various modifications made within the scope of the claims and the equivalent significance of disclosure are considered to be within the scope of the invention. [Explanation of symbols]

[0058] 1 Vehicle, 2,2L,2R Front wheels, 3,3L,3R Rear wheels, 5,5L,5R Front hydraulic brakes, 6,6L,6R Rear hydraulic brakes, 7 Brake actuator, 8 Electric parking brake, 9 Electric parking brake controller (EPB controller), 10 Mode selection switch, 11 Accelerator position sensor, 12 Tilt sensor, 13,13L,13R Wheel speed sensor, 100 Brake control device, 101 Starting intention detection unit, 102 Freezing detection unit, 103 Brake control unit, 1010 Bus, 1011 Processor, 1012 Memory, 1013 Storage, 1014 Communication interface.

Claims

1. A brake control device for a vehicle equipped with an electric parking brake that applies braking force to the rear wheels to fix the vehicle in place when parked, wherein at least the rear wheels are drive wheels, and the processor of the brake control device is The driver's intention to start the vehicle is detected, When the aforementioned intention to start is detected, it is determined whether or not the electric parking brake is frozen. If it is determined that the electric parking brake is frozen, the system will perform a starting control that applies braking force to the front wheels or both the front and rear wheels of the vehicle. Brake control device.

2. The aforementioned processor, In the aforementioned starting control, braking force is applied to the front wheels based on the accelerator pedal opening, which indicates the amount the accelerator pedal is pressed. The brake control device according to claim 1.

3. The aforementioned processor, In the aforementioned starting control, if the wheel speed of one of the left or right rear wheels is above a threshold and the wheel speed of the other wheel is below the threshold, braking force is applied to the rear wheel whose wheel speed is above the threshold. The brake control device according to claim 1.

4. The aforementioned processor, In the aforementioned starting control, if the wheel speed of both the left and right rear wheels is above a threshold, the applied braking force is gradually reduced. The brake control device according to claim 1.

5. The aforementioned processor, The starting control is executed only when the vehicle's operating mode is set to a specific mode. The brake control device according to claim 1.

6. The aforementioned processor, If the vehicle is a four-wheel drive vehicle, the driving force to the front wheels is turned off before the starting control is executed. The brake control device according to claim 1.

7. A braking method for a vehicle equipped with an electric parking brake that applies braking force to the rear wheels to fix the vehicle in place when parked, wherein at least the rear wheels are drive wheels, The driver's intention to start the vehicle is detected, When the aforementioned intention to start is detected, it is determined whether or not the electric parking brake is frozen. If it is determined that the electric parking brake is frozen, braking force is applied to the front wheels or both the front and rear wheels of the vehicle. The method of braking a vehicle.

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