Brake control device and brake control method

Abstract

To provide a technique that improves brake feeling while suppressing the occurrence of oscillation in a pitch direction when a vehicle is stopped.SOLUTION: A brake control device includes: a determination unit that determines requested deceleration of a driver on the basis of an acquired brake pedal operation amount; and a braking processing unit that determines a braking amount to be executed by a brake device on the basis of the determined requested deceleration and determines execution of reduction control that reduces the deceleration relative to the requested deceleration immediately before the vehicle is stopped. The braking processing unit is capable of executing increase control that increases the deceleration relative to the requested deceleration before the reduction control is executed, and determines whether to execute the increase control on the basis of the detection results of an on-vehicle sensor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a brake control for gently changing the deceleration just before the vehicle stops.

Background Art

[0002] Patent Document 1 discloses a control device that, when stopping a vehicle while applying a braking force to the vehicle, executes a decrease control for decreasing the braking force according to a braking request before the vehicle stops in order to suppress the pitching behavior of the vehicle that occurs when the braking force is applied to the vehicle, and also executes an increase control for increasing the braking force according to the braking request before the decrease control.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology disclosed in Patent Document 1, since the increase control and the decrease control are executed just before the vehicle stops, there is a possibility that the amount of change in the deceleration increases and the brake feeling deteriorates.

[0005] An object of the present invention is to provide a technique for improving the brake feeling while suppressing the occurrence of pitching oscillation in the pitch direction when the vehicle stops.

Means for Solving the Problems

[0006] In order to solve the above problems, a brake control device according to an aspect of the present invention includes an acquisition unit that acquires an operation amount of a driver's brake pedal and a detection result of an in-vehicle sensor, and a determination unit that determines a required deceleration of the driver based on the acquired operation amount of the brake pedal. An estimation unit estimates the estimated required deceleration, which is the deceleration required from the initial stage of deceleration onward, based on the initial brake pedal operation amount when the driver starts to press the brake pedal, and calculates an increased required deceleration by increasing the estimated required deceleration.The system includes a braking unit that determines the amount of braking to be performed by the braking device based on the determined required deceleration, and decides to perform reduction control to reduce the deceleration to a level lower than the required deceleration just before stopping the vehicle. The braking unit is capable of performing increase control to increase the deceleration to a level higher than the required deceleration before performing the decrease control, and decides whether to perform increase control based on the detection results of the on-board sensors. If the difference between the requested increased deceleration and the requested deceleration is within a predetermined range, the braking unit decides to perform increased deceleration control to control the brake device with the requested increased deceleration. If the difference between the requested increased deceleration and the requested deceleration is outside the predetermined range, the braking unit decides not to perform increased deceleration control.

[0007] Another aspect of the present invention is a brake control method in which each step is performed by a vehicle brake control device. This method includes the steps of: acquiring the amount of brake pedal operation by the driver and the detection result of an on-board sensor; determining the driver's requested deceleration based on the acquired brake pedal operation amount; and starting to control the amount of braking to be performed by the brake device based on the determined requested deceleration. The process involves estimating the estimated required deceleration, which is the deceleration required from the initial stage of deceleration onward, based on the initial brake pedal operation amount when the driver starts to press the brake pedal, and then calculating an increased required deceleration by increasing the estimated required deceleration. The system includes the steps of: determining whether to perform increased braking control, which increases the braking amount to a level greater than the required deceleration, based on the detection results of an on-board sensor before stopping the vehicle; performing increased braking control if it is determined that increased braking control should be performed; and performing decreased braking control, which reduces the braking amount to a level greater than the required deceleration, when stopping the vehicle. In the step of determining whether or not to perform increased deceleration control, if the difference between the increased deceleration request and the requested deceleration is within a predetermined range, it is decided to perform increased deceleration control to control the brake device at the increased increased deceleration; if the difference between the increased deceleration request and the requested deceleration is outside the predetermined range, it is decided not to perform increased deceleration control. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a technology that improves brake feel while suppressing pitch-direction oscillation when the vehicle is stopped. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram illustrating the operation of the brake control system of the first embodiment. [Figure 2] This diagram shows the functional configuration of the brake control system. [Figure 3] This is a flowchart of the brake control method according to the first embodiment. [Figure 4] This is a diagram illustrating the operation of the brake control system of the second embodiment. [Figure 5] This is a flowchart of the brake control method in the second embodiment. [Modes for carrying out the invention]

[0010] (First embodiment) Figure 1 is a diagram illustrating the operation of the brake control system of the first embodiment. Figure 1(a) shows the relationship between vehicle speed V and time T in brake control, and Figure 1(b) shows the relationship between deceleration B and time T in brake control. The time T shown in Figures 1(a) and 1(b) represents the same period of time.

[0011] The first vehicle speed 10 and the first deceleration 14 represent the control results performed by the brake control system of the embodiment, while the second vehicle speed 12 and the second deceleration 16 represent the control results performed by the brake control system of the comparative technology. The comparative technology is a technology used for comparison with the brake control system of the first embodiment.

[0012] The changes in the second vehicle speed 12 and second deceleration 16 of the comparative technology are described below. At time t1, braking begins, the second deceleration 16 starts to increase, and the second vehicle speed 12 starts to decrease. At time t2, control to increase the second deceleration 16 is started, and the second deceleration 16 increases beyond the driver's requested deceleration B1 at time t2, causing the second vehicle speed 12 to decrease sharply. At time t3, the control to increase the second deceleration 16 ends, and the second deceleration 16 starts to decrease below the driver's requested deceleration at time t3. At time t4, the second vehicle speed 12 becomes zero, and the vehicle comes to a stop.

[0013] In the comparative technology, the second deceleration 16 decreases below the driver's requested deceleration from time t3 to time t4, just before the vehicle stops, thus suppressing the pitch oscillation of the vehicle when it stops. Also, from time t2 to time t3, the second deceleration 16 increases below the driver's requested deceleration, compensating for the decrease in the second deceleration 16 just before the vehicle stops, and ultimately matching the driver's requested deceleration. Control that increases the deceleration from time t2 to time t3 below the driver's requested deceleration is called increasing control. Control that decreases the deceleration from time t3 to time t4 below the driver's requested deceleration is called decreasing control.

[0014] In the comparative technology, the second deceleration 16 results in a larger change before the vehicle comes to a complete stop, which may cause the driver to perceive a large change in acceleration and feel an unnatural sensation.

[0015] In the brake control system of the first embodiment, at time t1, braking begins and the first deceleration 14 starts to increase, and the first vehicle speed 10 starts to decrease. At time t2, the first deceleration 14 starts to decrease in response to the driver's operation. At time t3, the first deceleration 14 starts to decrease below the driver's requested deceleration at time t3. At time t4, the vehicle does not stop, and at time t5, the first vehicle speed 10 becomes zero and the vehicle stops.

[0016] The first vehicle speed 10, corresponding to the first embodiment, results in a later vehicle stopping timing than the second vehicle speed 12, corresponding to the comparative technology, but the speed change is smoother than that of the second vehicle speed 12. As a result, the brake control system of the embodiment can suppress acceleration changes that occur when the vehicle stops, while also suppressing pitch oscillations that occur when the vehicle stops, compared to the comparative technology.

[0017] FIG. 2 is a diagram showing the functional configuration of the brake control system 20. Each function of the brake control system 20 can be hardware-wise composed of circuit blocks, memories, and other LSIs, and software-wise realized by system software or application programs loaded into the memory. Therefore, it is understood by those skilled in the art that each function of the brake control system 20 can be realized in various forms by only hardware, only software, or a combination thereof, and is not limited to any one. The brake control system 20 is provided in a vehicle, and the vehicle may be capable of autonomous driving.

[0018] The brake control system 20 includes a brake control device 22, a pedal operation detection sensor 24, an in-vehicle sensor 26, and a brake device 28.

[0019] The pedal operation detection sensor 24 detects the amount of brake pedal operation, i.e., the deceleration required by the driver, and transmits the detection result to the brake control device 22. The pedal operation detection sensor 24 is, for example, a stroke sensor that detects the amount of depression of the brake pedal and may be a sensor that detects the master cylinder pressure.

[0020] The in-vehicle sensor 26 includes a plurality of sensors mounted on the vehicle and includes a driving state detection sensor that detects the driving state of the vehicle and an object detection sensor that detects an object located around the vehicle. The driving state detection sensor has a vehicle speed sensor, an acceleration sensor, a position information detection sensor, a brake output detection sensor, etc. The vehicle speed sensor detects the driving speed of the vehicle and may be, for example, a wheel speed sensor. The acceleration sensor detects the acceleration of the vehicle. The position information detection sensor acquires the position information of the vehicle using GNSS (Global Navigation Satellite System). The brake output detection sensor detects the output of the brake device 28.

[0021] Object detection sensors include in-vehicle cameras, millimeter-wave radar, ultrasonic sensors, and optical ranging sensors. The in-vehicle camera captures images of the area around the vehicle and generates captured images. The millimeter-wave radar, ultrasonic sensors, and optical ranging sensors detect the distance and direction of objects.

[0022] The object detection sensor detects objects that should be stopped. These objects include objects that obstruct the vehicle's movement and signs that instruct the vehicle to stop, such as other vehicles, pedestrians, and road fixtures such as crosswalks and stop lines.

[0023] The brake device 28 is a hydraulic brake device that applies frictional force to the wheels and is driven by the brake control device 22 to apply braking force to the vehicle.

[0024] The brake control device 22 comprises an acquisition unit 30, a determination unit 32, an estimation unit 34, a recognition processing unit 36, a braking processing unit 38, and a control unit 40. The acquisition unit 30 acquires the amount of brake pedal operation by the driver detected by the pedal operation detection sensor 24, and the detection results from the on-board sensor 26.

[0025] The determination unit 32 determines the deceleration to be exerted by the brake device 28 based on the detection result of the pedal operation detection sensor 24. The determination unit 32 also determines the driver's requested deceleration based on the amount of brake pedal operation.

[0026] The recognition processing unit 36 ​​performs object recognition processing based on the detection results of the object detection sensor and generates information about the object. The recognition processing unit 36 ​​analyzes the captured image and outputs the type of object and its location information. The recognition processing unit 36 ​​may use neural network methods in image analysis, or machine learning methods to extract objects. The recognition processing unit 36 ​​generates information about a stopping object located in the direction of the vehicle's movement and sends it to the braking processing unit 38. The information about a stopping object located in the direction of the vehicle's movement may be the location information of the stopping object, or it may be a flag indicating that the vehicle should stop.

[0027] The braking processing unit 38 instructs the control unit 40 to brake according to the driver's requested deceleration if it has not performed deceleration reduction control and deceleration increase control. The braking processing unit 38 determines the timing for performing deceleration reduction control, which is performed immediately before the vehicle comes to a stop, and deceleration increase control, which is performed before the deceleration reduction control. The vehicle coming to a stop is determined based on the driver's requested deceleration and objects present around the vehicle. The braking processing unit 38 also decides whether to perform deceleration increase control based on the detection results of the on-board sensor 26.

[0028] Deceleration control is a control mechanism that reduces the deceleration to a level lower than the driver's requested deceleration just before the vehicle comes to a stop. The braking processing unit 38 sets a deceleration start timing based on the requested deceleration and vehicle speed, and decides to execute the deceleration control until the vehicle comes to a stop. The deceleration control will terminate before the vehicle comes to a stop if the driver's requested deceleration increases. The braking processing unit 38 reduces the driver's requested deceleration according to a preset deceleration gradient. The start timing of the deceleration control may be set by the vehicle speed, and the braking processing unit 38 may set a vehicle speed at which deceleration starts.

[0029] Increase control is a control that compensates for the deceleration reduced by decrease control. The braking processing unit 38 sets the amount of increase in deceleration in increase control based on the difference between the integral value of the deceleration reduced by decrease control and the integral value of the deceleration if decrease control were not performed. The integral value of the deceleration reduced by decrease control may be converted into a travel distance, and the braking processing unit 38 may estimate the first braking distance when decrease control is performed and the second braking distance when decrease control is not performed, and set the amount of increase in deceleration in increase control according to the difference between the first braking distance and the second braking distance. The braking processing unit 38 sets the vehicle speed at which increase starts, which corresponds to the timing of increase start, based on the current deceleration and vehicle speed.

[0030] The braking processing unit 38 decides to perform acceleration control when it detects the presence of an object to be stopped in the direction of the vehicle's travel, and decides not to perform acceleration control when it does not detect the presence of an object to be stopped in the direction of the vehicle's travel. This allows acceleration control to be performed when an object to be stopped is in the direction of the vehicle's travel to compensate for the deceleration reduced by the deceleration control. If there is no object to be stopped in the direction of the vehicle's travel, acceleration control is not performed and deceleration control is performed, which increases the braking distance of the vehicle, but suppresses oscillation in the pitch direction.

[0031] The control unit 40 controls the amount of braking performed by the brake device 28 based on the determined required deceleration. In response to the decision of the braking processing unit 38, the control unit 40 performs a reduction control that reduces the deceleration to less than the required deceleration just before the vehicle comes to a stop. This suppresses the pitch oscillation that occurs when the vehicle stops.

[0032] The control unit 40 is capable of performing an increase control, which increases the deceleration beyond the requested deceleration, before executing a decrease control, and performs the increase control according to the decision of the braking processing unit 38.

[0033] Figure 3 is a flowchart of the brake control method of the first embodiment. This process is performed periodically. The acquisition unit 30 acquires the brake pedal operation amount from the pedal operation detection sensor 24 (S10), and the determination unit 32 calculates the driver's requested deceleration from the brake pedal operation amount. The braking processing unit 38 determines whether the vehicle is braking, that is, whether the requested deceleration is greater than zero (S12).

[0034] If the vehicle is not braking (N in S12), this process is terminated. If the vehicle is braking (Y in S12), the braking processing unit 38 determines whether the vehicle has not yet stopped, that is, whether the vehicle is still moving (S14). If the vehicle is stopped (N in S14), normal braking control is performed according to the requested deceleration without performing acceleration control or deceleration control (S28).

[0035] If the vehicle has not yet come to a complete stop (Y in S14), the braking unit 38 determines whether it is time to start the deceleration control (S16). The determination of whether it is time to start the deceleration control is made when the vehicle speed has decreased to the deceleration start speed set by the braking unit 38.

[0036] If it is the start timing for the reduction control (Y in S16), the braking processing unit 38 decides to start the reduction control, the control unit 40 executes the reduction control (S18), and the process ends. If it is not the start timing for the reduction control (N in S16), the braking processing unit 38 obtains the object recognition result from the recognition processing unit 36 ​​(S20) and determines whether it has detected that there is an object to be stopped in the direction of the vehicle's movement (S22).

[0037] If the vehicle detects that there is an object to be stopped in the direction of travel (Y in S22), the braking processing unit 38 determines whether it is time to start the acceleration control (S24). Whether it is time to start the acceleration control is determined by whether the vehicle speed falls below the acceleration start vehicle speed.

[0038] If it is determined that it is time to start the acceleration control (Y in S24), the braking processing unit 38 decides to start the acceleration control, and the control unit 40 executes the acceleration control (S26). If it is determined that it is not time to start the acceleration control (N in S24), the control unit 40 controls the brake device 28 with a braking amount corresponding to the driver's requested deceleration, executes normal braking control (S28), and this process ends. If no object to be stopped is detected in the direction of travel of the vehicle (N in S22), the braking processing unit 38 decides to execute normal braking control (S28).

[0039] (Second example) Figure 4 is a diagram illustrating the operation of the brake control system 20 of the second embodiment. Figure 4(a) shows the relationship between vehicle speed V and time T in brake control, and Figure 4(b) shows the relationship between deceleration B and time T in brake control. The time T shown in Figures 4(a) and 4(b) represents the same period of time. The second embodiment will be explained with reference to Figure 2.

[0040] In the brake control system 20 of the second embodiment, the braking processing unit 38 can decide to perform deceleration control to reduce the deceleration to a level lower than the driver's requested deceleration just before stopping the vehicle, and can perform acceleration control to increase the deceleration to a level lower than the driver's requested deceleration before performing deceleration control. The braking processing unit 38 then decides whether to perform acceleration control based on the detection result of the on-board sensor 26.

[0041] The first vehicle speed 42 and the first deceleration 48 represent the control results performed by the brake control system 20 of the second embodiment, while the second vehicle speed 44 and the second deceleration 50 represent the control results performed by the brake control system of the comparative technology. The comparative technology is a technology used for comparison with the brake control system of the second embodiment, and is the same as the comparative technology shown in Figure 1.

[0042] The changes in the second vehicle speed 44 and second deceleration 50 of the comparative technology will be explained. At time t1 shown in Figure 4, braking begins and the second deceleration 50 starts to increase, and the second vehicle speed 44 starts to decrease. At time t4, control to increase the second deceleration 50 is started, and the second deceleration 50 increases beyond the driver's requested deceleration at time t4, causing the second vehicle speed 44 to decrease sharply. After that, the control to increase the second deceleration 50 ends, and the second deceleration 50 starts to decrease below the driver's requested deceleration. At time t8, the second vehicle speed 44 becomes zero, and the vehicle stops. The second vehicle speed 44 of the comparative technology fluctuates up and down compared to the straight reference line 46.

[0043] In the brake control system 20 of the second embodiment, at time t1, braking begins, the first deceleration 48 begins to increase, and the first vehicle speed 42 begins to decrease. At time t2, acceleration control begins. In the acceleration control performed at time t3, the deceleration is higher than the estimated required deceleration B1. The actual driver's requested deceleration B2 is slightly different from the estimated required deceleration B1. The estimated required deceleration B1 is calculated from the amount of brake pedal operation at time t2 and the rate at which the brake pedal operation increases. At time t5, the first deceleration 48 begins to decrease, and at time t6, when the first vehicle speed 42 reaches the vehicle speed at which the decrease begins, acceleration control begins. The first vehicle speed 42 changes more gradually than the second vehicle speed 44 in the comparative technology. Also, because the estimated required deceleration B1 was greater than the actual required deceleration B2, the first vehicle speed 42 becomes zero at time t7, and the vehicle stops earlier than at time t8 when the second vehicle speed 44 becomes zero in the comparative technology.

[0044] Returning to Figure 2, the estimation unit 34 estimates the estimated required deceleration, which is the deceleration required after the initial deceleration, based on the initial brake pedal operation amount when the driver begins to press the brake pedal. The initial deceleration refers, for example, to the period from time t1 to time t2 shown in Figure 4(b), and may be about 1 second from the start of operation. The estimated required deceleration is estimated by the initial brake pedal operation amount and the rate at which the brake pedal operation amount increases, and may be estimated by referring to a pre-held map. The driver presses the brake pedal and maintains the pressed state at the desired stroke position. The estimated required deceleration estimates the stroke position maintained by the driver using the initial brake pedal operation amount.

[0045] The estimation unit 34 calculates an increased requested deceleration by adding a predetermined amount to the estimated requested deceleration. The increased requested deceleration is the deceleration used in the increased deceleration control, and by adding a predetermined amount, it becomes greater than the driver's requested deceleration. In the increased deceleration control shown in Figure 4(b), braking is performed with an increased requested deceleration that is greater than the estimated requested deceleration B1. The estimation unit 34 may also calculate the increased requested deceleration based on the initial brake pedal operation amount and the rate at which the brake pedal operation amount increases.

[0046] The braking unit 38 decides to perform increased deceleration control, which controls the brake device 28 at the increased deceleration, if the difference between the requested increased deceleration and the requested deceleration is within a predetermined range. The braking unit 38 also decides not to perform increased deceleration control if the difference between the requested increased deceleration and the requested deceleration is outside the predetermined range. In other words, increased deceleration control is performed if the absolute value of the difference between the requested increased deceleration and the requested deceleration is less than or equal to a predetermined value, and not performed if it is greater than the predetermined value. The predetermined range is set through experiments or other means to minimize the driver's discomfort with the brake feel due to the discrepancy between the driver's requested deceleration and the requested increased deceleration.

[0047] When increasing deceleration control is being performed, if the difference between the requested increased deceleration and the requested deceleration falls outside a predetermined range, the braking processing unit 38 stops the increasing deceleration control and performs normal braking control, that is, control according to the requested deceleration.

[0048] Since the increased deceleration requirement is calculated based on the initial brake pedal operation, the increased deceleration control starts earlier, allowing for gradual braking control until the increased deceleration requirement is reached. The increased deceleration control continues until the decreased deceleration control is performed, and after the increased deceleration control, the decreased deceleration control is executed from the start timing of the decrease, similar to the first embodiment. By executing the increased deceleration control, the deceleration that decreases during the decreased deceleration control can be compensated for.

[0049] Figure 5 is a flowchart of the brake control method of the second embodiment. This process is executed periodically. The acquisition unit 30 acquires the brake pedal operation amount from the pedal operation detection sensor 24 (S30). The braking processing unit 38 determines whether the vehicle is braking, that is, whether the brake pedal operation amount is greater than zero (S32).

[0050] If the vehicle is not braking (N in S32), this process ends. If the vehicle is braking (Y in S32), the braking processing unit 38 determines whether the vehicle has not yet stopped, that is, whether the vehicle is still moving (S34). If the vehicle is stopped (N in S34), the normal braking control is performed according to the requested deceleration without performing acceleration control or deceleration control (S52).

[0051] If the vehicle has not yet come to a stop (Y in S34), the braking processing unit 38 determines whether the brake pedal is in the initial stage of being pressed (S36). If it is in the initial stage of being pressed (Y in S36), the estimation unit 34 estimates the estimated required deceleration, which is the deceleration required from the initial stage of pressing onwards, based on the initial brake pedal operation amount, and calculates an increased required deceleration by increasing the estimated required deceleration (S38).

[0052] The determination unit 32 calculates the driver's requested deceleration based on the amount of brake pedal operation (S40). The braking processing unit 38 determines whether the difference between the requested increased deceleration and the driver's requested deceleration is within a predetermined range (S42). If the difference between the requested increased deceleration and the driver's requested deceleration is within a predetermined range (Y in S42), the braking processing unit 38 decides to perform increased deceleration control, and the control unit 40 controls with a braking amount corresponding to the requested increased deceleration (S44).

[0053] If it is not the initial stage of pressing the pedal (N in S36), the braking processing unit 38 determines whether acceleration control is in progress, that is, whether acceleration control was performed in the previous session (S46). If acceleration control is in progress (Y in S46), the determination unit 32 calculates the required deceleration according to the detection result of the pedal operation detection sensor 24 (S40). The braking processing unit 38 determines whether the difference between the requested acceleration deceleration and the driver's requested deceleration is within a predetermined range (S42). If the difference between the requested acceleration deceleration and the driver's requested deceleration is within a predetermined range (Y in S42), acceleration control is continued.

[0054] If the difference between the requested deceleration increase and the driver's requested deceleration is not within a predetermined range (N in S42), the braking processing unit 38 determines whether it is time to start deceleration control (S48). Also, if deceleration increase control is not in progress, i.e., if deceleration increase control is not continuing (N in S46), the braking processing unit 38 determines whether it is time to start deceleration control (S48). If it is time to start deceleration control (Y in S48), the braking processing unit 38 decides to start deceleration control, the control unit 40 executes deceleration control (S50), and this process ends.

[0055] If it is not the start timing for deceleration control (N in S48), the control unit 40 performs normal braking control according to the requested deceleration without performing acceleration control or deceleration control (S52).

[0056] The present disclosure has been explained above based on the examples described. The present disclosure is not limited to the examples described above, and various modifications such as design changes can be made based on the knowledge of those skilled in the art. [Explanation of symbols]

[0057] 10 First vehicle speed, 12 Second vehicle speed, 14 First deceleration, 16 Second deceleration, 20 Brake control system, 22 Brake control device, 24 Pedal operation detection sensor, 26 On-board sensor, 28 Brake device, 30 Acquisition unit, 32 Determination unit, 34 Estimation unit, 36 Recognition processing unit, 38 Braking processing unit, 40 Control unit, 42 First vehicle speed, 44 Second vehicle speed, 48 First deceleration, 50 Second deceleration.

Claims

1. An acquisition unit that acquires the amount of brake pedal operation by the driver and the detection result of the on-board sensor, A determination unit that determines the driver's requested deceleration based on the acquired brake pedal operation amount, An estimation unit estimates the estimated required deceleration, which is the deceleration required from the initial stage of pressing the brake pedal, based on the initial amount of brake pedal operation when the driver starts to press the brake pedal, and calculates an increased required deceleration, which is an increased version of the estimated required deceleration. The system includes a braking processing unit that determines the amount of braking to be performed by the braking device based on the determined required deceleration, and decides to perform reduction control to reduce the deceleration to a level lower than the required deceleration just before stopping the vehicle, The braking processing unit is capable of performing an increase control to increase the deceleration beyond the requested deceleration before executing the decrease control, and decides whether to perform the increase control based on the detection result of the on-board sensor. A brake control device characterized in that, if the difference between the requested increased deceleration and the requested deceleration is within a predetermined range, the braking processing unit decides to perform the increased deceleration control to control the brake device with the requested increased deceleration, and if the difference between the requested increased deceleration and the requested deceleration is outside the predetermined range, the braking processing unit decides not to perform the increased deceleration control.

2. The detection results of the on-board sensor include information regarding the object to be stopped located in the direction of travel of the vehicle. The brake control device according to claim 1, characterized in that the braking processing unit decides to execute the augmentation control when it detects that an object to be stopped exists in the direction of travel of the vehicle, and decides not to execute the augmentation control when it does not detect that an object to be stopped exists in the direction of travel of the vehicle.

3. A brake control method in which each step is performed by a vehicle brake control device, The steps include obtaining the driver's brake pedal operation amount and the detection result from the on-board sensor, The steps include determining the driver's requested deceleration based on the acquired brake pedal operation amount, A step of starting to control the amount of braking to be performed by the braking device based on the determined required deceleration, The steps include: estimating the estimated required deceleration, which is the deceleration required from the initial stage of pressing the brake pedal, based on the initial amount of brake pedal operation when the driver starts pressing the brake pedal; and calculating an increased required deceleration, which is an increased version of the estimated required deceleration; The steps include determining, based on the detection results of the on-board sensor, whether or not to perform an acceleration control that increases the deceleration beyond the requested deceleration before stopping the vehicle, If it is decided to perform the aforementioned increase control, the step of performing the aforementioned increase control, The step of performing deceleration control to reduce the deceleration rate to a rate lower than the requested deceleration rate when stopping the vehicle, A brake control method characterized in that, in the step of determining whether or not to perform the increased deceleration control, if the difference between the increased deceleration request and the requested deceleration is within a predetermined range, it is decided to perform the increased deceleration control to control the brake device with the increased deceleration request; and if the difference between the increased deceleration request and the requested deceleration is outside the predetermined range, it is decided not to perform the increased deceleration control.

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