Braking control method and system, medium, and vehicle

Abstract

A braking control method, comprising the following steps performed by a vehicle: S100: selectively activating a braking control function during braking of the vehicle; S200: acquiring a specific gradient value; S300: planning a control target; and S400: adjusting a motor torque and a hydraulic pressure on the basis of the control target so that a deceleration of the vehicle is reduced, wherein the motor torque is a driving torque output by a driving motor and is positive, the hydraulic pressure is a braking pressure of a hydraulic braking system of the vehicle, and the hydraulic pressure is set to be less than a braking request pressure for at least a certain duration during step S400. Further disclosed are a braking control system, a medium, and the vehicle.

Description

Braking control method, system, medium and vehicle Technical Field

[0001] The present application relates to the field of vehicle control. More specifically, the present application relates to a brake control method, which is intended to provide an improved parking or braking experience. The present application also relates to a brake control system, a medium, and a vehicle. Background Art

[0002] Vehicle braking is typically performed using a braking system, which typically includes a hydraulic system that applies hydraulic pressure to the wheels. The hydraulic pressure in a typical braking system is typically equal to the brake request pressure and provides a certain level of deceleration. During vehicle braking, the vehicle body is subjected to significant inertial forces and possesses considerable kinetic energy. In the moments leading up to or immediately before a braking stop, inertial forces create a near-step force input to the vehicle's vibration system, causing significant vibration and shock. Simultaneously, the vehicle's suspension system is stressed and experiences compression or extension, resulting in significant pitching motion, rapidly absorbing some of the kinetic energy. During this process, the vehicle tends to experience a "brake nod" phenomenon. This significant deceleration and pitching motion can cause longitudinal and pitching shocks to the driver and passengers, resulting in an uncomfortable user experience. This phenomenon is particularly noticeable when the vehicle is braking or braking at a high deceleration. Summary of the Invention

[0003] One aspect of the present application is to provide a braking control method that can provide an improved user experience. Another aspect of the present application is to provide a braking control system. Another aspect of the present application is to provide a medium. Another aspect of the present application is to provide a vehicle.

[0004] The purpose of the present application is achieved through the following technical solutions: A braking control method, comprising the following steps performed by a vehicle: S100: selectively activating a braking control function during vehicle braking; S200: obtaining a specific slope value; S300: planning a control target; and S400: adjusting the motor torque and hydraulic pressure according to the control target to reduce the deceleration of the vehicle; wherein the motor torque is the driving torque output by the driving motor and is positive, the hydraulic pressure is the braking pressure of the vehicle's hydraulic braking system, and the hydraulic pressure is set to be less than the braking request pressure for at least a certain time during step S400.

[0005] In the above brake control method, optionally, step S100 includes a sub-step S120: activating the brake control function when the vehicle speed is less than or equal to the target activation speed.

[0006] In the above braking control method, optionally, the target activation vehicle speed is calculated by a real-time value of the wheel angular deceleration, and the target activation vehicle speed is between 3 and 7 kilometers per hour.

[0007] In the above-mentioned braking control method, optionally, step S100 also includes sub-step S110: before sub-step S120, judging whether the activation condition is met; wherein, whether the activation condition is met is judged by the real-time values ​​of one or more of the following parameters: vehicle movement direction, lateral acceleration, longitudinal deceleration, vehicle speed, preliminary slope value, and vehicle safety function.

[0008] In the above brake control method, optionally, step S100 further includes a sub-step S130: when the activation condition is not satisfied, maintaining the hydraulic pressure equal to the brake request pressure.

[0009] In the above-mentioned braking control method, optionally, in step S200, the specific value of the slope is calculated by the real-time values ​​of one or more of the following parameters: vehicle acceleration, wheel angular deceleration, and vehicle pitch angular velocity; in step S300, the control target is planned based on the specific value of the slope, and includes: a target for motor torque and a target for hydraulic pressure.

[0010] In the above-mentioned braking control method, optionally, in step S400, the hydraulic pressure is adjusted to be less than the braking request pressure, at least within a certain period of time, and at the same time, a positive motor torque is applied to reduce the deceleration to a predetermined level; wherein the positive motor torque tends to drive the vehicle forward in the longitudinal direction, and the deceleration is always maintained greater than zero.

[0011] In the above braking control method, optionally, the motor torque is calculated based on real-time values ​​of one or more of the following parameters: vehicle speed, slope specific value, and wheel angular deceleration.

[0012] In the above-mentioned braking control method, optionally, in step S400, the hydraulic pressure goes through the following stages: a hydraulic pressure reduction stage, in which the hydraulic pressure continues to decrease from being equal to the braking request pressure; and a hydraulic pressure maintenance stage, in which the hydraulic pressure is maintained at a first value; and the motor torque goes through the following stages: a motor torque increase stage, in which the motor torque continues to increase; and a motor torque maintenance stage, in which the motor torque is maintained at a second value.

[0013] In the above-mentioned braking control method, optionally, the start time of the motor torque reduction phase corresponds to the start time of the hydraulic pressure increase phase and is earlier than the time when the vehicle completely stops; and wherein, the start time of the motor torque maintenance phase is earlier than the start time of the hydraulic pressure maintenance phase.

[0014] In the above-mentioned braking control method, optionally, it also includes: Step S500: After activating the braking control function, continuously monitoring one or more of the following vehicle operating parameters to determine whether there is a safety risk: the travel of the driving pedal and the brake pedal, the direction of wheel travel, the wheel angular deceleration, and the vehicle speed; Step S600: When it is determined that there is a safety risk, adjusting the hydraulic pressure to be equal to the braking request pressure, and adjusting the motor torque to zero; and Step S700: After the vehicle stops, adjusting the hydraulic pressure to be equal to the braking request pressure, and adjusting the motor torque to zero.

[0015] A braking control system, which is arranged in a vehicle and can be used for braking control in the vehicle, includes: at least one memory; at least one processor; and a computer program, which is stored on the memory and can be run on the processor, wherein the running of the computer program causes the following steps to be executed: S100: selectively activating the braking control function during vehicle braking; S200: obtaining a specific value of the slope; S300: planning a control target; and S400: adjusting the motor torque and hydraulic pressure according to the control target to reduce the deceleration of the vehicle; wherein the motor torque is the driving torque output by the driving motor and is positive, the hydraulic pressure is the braking pressure of the vehicle's hydraulic braking system, and the hydraulic pressure is set to be less than the braking request pressure for at least a certain time during step S400.

[0016] In the above braking control system, optionally, step S100 includes a sub-step S120: activating the braking control function when the vehicle speed is less than or equal to the target activation speed.

[0017] In the above braking control system, optionally, the target activation vehicle speed is calculated by a real-time value of the wheel angular deceleration, and the target activation vehicle speed is between 3 and 7 kilometers per hour.

[0018] In the above-mentioned braking control system, optionally, step S100 also includes sub-step S110: before sub-step S120, determine whether the activation condition is met; wherein, whether the activation condition is met is determined by the real-time values ​​of one or more of the following parameters: vehicle movement direction, lateral acceleration, longitudinal deceleration, vehicle speed, preliminary slope value, and vehicle safety function.

[0019] In the above braking control system, optionally, step S100 further includes a sub-step S130: when the activation condition is not satisfied, maintaining the hydraulic pressure equal to the braking request pressure.

[0020] In the above-mentioned braking control system, optionally, in step S200, the specific value of the slope is calculated by the real-time values ​​of one or more of the following parameters: vehicle acceleration, wheel angular deceleration, and vehicle pitch angular velocity; in step S300, the control target is planned based on the specific value of the slope, and includes: a target for motor torque and a target for hydraulic pressure.

[0021] In the above-mentioned braking control system, optionally, in step S400, the hydraulic pressure is adjusted to be less than the braking request pressure, at least for a certain period of time, and at the same time, a positive motor torque is applied to reduce the deceleration to a predetermined level; wherein the positive motor torque tends to drive the vehicle forward in the longitudinal direction, and the deceleration is always maintained greater than zero.

[0022] In the above braking control system, optionally, the motor torque is calculated based on real-time values ​​of one or more of the following parameters: vehicle speed, slope specific value, and wheel angular deceleration.

[0023] In the above-mentioned braking control system, optionally, in step S400, the hydraulic pressure goes through the following stages: a hydraulic pressure reduction stage, in which the hydraulic pressure continues to decrease from being equal to the braking request pressure; and a hydraulic pressure maintenance stage, in which the hydraulic pressure is maintained at a first value; and the motor torque goes through the following stages: a motor torque increase stage, in which the motor torque continues to increase; and a motor torque maintenance stage, in which the motor torque is maintained at a second value.

[0024] In the above-mentioned braking control system, optionally, the start time of the motor torque reduction phase corresponds to the start time of the hydraulic pressure increase phase and is earlier than the time when the vehicle completely stops; and wherein, the start time of the motor torque maintenance phase is earlier than the start time of the hydraulic pressure maintenance phase.

[0025] In the above-mentioned braking control system, optionally, the operation of the computer program also causes the following steps to be executed: Step S500: After activating the braking control function, continuously monitor one or more of the following vehicle operating parameters to determine whether there is a safety risk: the travel of the driving pedal and the brake pedal, the direction of wheel travel, the wheel angular deceleration, and the vehicle speed; Step S600: When it is determined that there is a safety risk, the hydraulic pressure is adjusted to be equal to the braking request pressure, and the motor torque is adjusted to zero; and Step S700: After the vehicle stops, the hydraulic pressure is adjusted to be equal to the braking request pressure, and the motor torque is adjusted to zero.

[0026] A computer-readable storage medium stores a computer program. When executed by a processor, the computer program implements the above-mentioned braking control method.

[0027] A vehicle comprises the above-mentioned braking control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present application will be described in further detail below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will appreciate that these drawings are drawn only for the purpose of illustrating the preferred embodiments and, therefore, should not be construed as limiting the scope of the present application. Furthermore, unless otherwise noted, the drawings are intended only to conceptually represent the composition or configuration of the depicted objects and may contain exaggerated illustrations. The drawings are not necessarily drawn to scale.

[0029] FIG1 is a flow chart of an embodiment of a braking control method of the present application.

[0030] FIG. 2 is a detailed view of step S100 of the embodiment shown in FIG. 1 .

[0031] FIG3 is a process diagram illustrating changes in various parameters during the braking process of an embodiment of a vehicle of the present application.

[0032] FIG4 is a schematic diagram of an embodiment of a brake control system of the present application. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely illustrative and exemplary and should not be construed as limiting the scope of protection of the present application.

[0034] First, it should be noted that directional terms such as top, bottom, upward, and downward, as used herein, are defined relative to the directions in the respective figures. These directions are relative and will vary depending on the position and state of the device. Therefore, these and other directional terms should not be construed as limiting.

[0035] In addition, it should be pointed out that for any single technical feature described or implied in the embodiments of this document or any single technical feature shown or implied in the accompanying drawings, these technical features (or their equivalents) can be further combined to obtain other embodiments not directly mentioned in this document.

[0036] It should be noted that in different drawings, the same reference numerals denote the same or substantially the same components.

[0037] Figures 1 and 2 illustrate an embodiment of the braking control method of the present application. According to one embodiment, the braking control method of the present application generally includes the following steps: S100: selectively activating a braking control function during vehicle braking; S200: obtaining a specific slope value; S300: determining a control target; and S400: adjusting motor torque and hydraulic pressure based on the control target to reduce vehicle deceleration.

[0038] It should be noted that the step names mentioned above (and those mentioned below) are merely used to distinguish between the steps and facilitate reference to the steps, and do not represent the order of the steps. The flowcharts, including the accompanying drawings, are merely examples of how to execute the present method. Unless there is an obvious conflict, the steps may be executed in various orders or simultaneously.

[0039] It should be noted that the motor torque referred to in this application is the driving torque output by the drive motor, and is positive. The solution disclosed in this application can be used for various new energy vehicles, including but not limited to pure electric vehicles, hybrid vehicles or hydrogen-powered vehicles. The drive motor referred to in this application refers to a motor that drives the vehicle forward or backward on a new energy vehicle. The movement of the vehicle forward or backward is also called longitudinal movement. For example, the drive motor referred to in this application can drive the vehicle forward or backward in the longitudinal direction. For another example, the drive motor referred to in this application can provide direct or indirect driving force for the wheels.

[0040] It should be noted that the vehicle involved in this application may have a brake or braking system, and the braking system may include a hydraulic transmission part. The hydraulic transmission part may have a certain hydraulic pressure. The hydraulic pressure referred to in this article can be understood as the braking pressure transmitted in the vehicle's hydraulic braking system. In one embodiment, the brake request pressure refers to the hydraulic pressure that matches the braking intention represented by the driver's action of stepping on the brake pedal. In one embodiment, the brake request pressure can be determined based on the travel, acceleration or pedaling force of the brake pedal. In one embodiment, the brake request may come from the vehicle's automatic driving system. Therefore, the brake request pressure may be the brake pressure requested by the automatic driving system.

[0041] FIG2 illustrates the detailed sub-steps of step S100 of the braking control method of the present application. Specifically, step S100 involves selectively activating a braking control function. In one embodiment, the braking control function can be activated when the vehicle speed is not higher than the target activation speed V1, as shown in sub-step S120 in FIG2 . For example, the braking control system of the present application can be configured to continuously monitor the vehicle speed, and activate the braking control function if the vehicle speed is less than or equal to the target activation speed V1. In one embodiment, the target activation speed V1 can be calculated based on the wheel angular deceleration. In one embodiment, the target activation speed V1 can be a function of the wheel angular deceleration. In one embodiment, the target activation speed V1 can be between 3 kilometers per hour and 7 kilometers per hour. It is easy to understand that the wheel angular deceleration described above can be the real-time value of the wheel angular deceleration read when executing step S100.

[0042] Furthermore, step S100 may also include sub-steps S110 and S130. As shown in Figure 2, sub-step S110 may be executed before sub-step S120. Specifically, sub-step S110 involves determining whether activation conditions are met. If the activation conditions are met, the process proceeds to sub-step S120. If the activation conditions are not met, the process proceeds to sub-step S130. The activation conditions detected in sub-step S110 include, but are not limited to, one or more of the following: vehicle direction of motion, lateral acceleration, longitudinal deceleration, vehicle speed, preliminary slope value, etc.

[0043] The lateral direction referred to herein refers to the direction perpendicular to the vehicle's direction of travel, i.e., the left and right directions perceived by the driver from the driver's seat, or in other words, the direction the side of the vehicle is facing. The longitudinal direction referred to herein refers to the vehicle's direction of travel, i.e., the front and rear directions perceived by the driver from the driver's seat, or in other words, the direction the vehicle is moving forward and backward.

[0044] The preliminary value of the slope referred to herein refers to an approximate value of the slope of the slope the vehicle is on. In one embodiment, the preliminary value of the slope is used to preliminarily determine whether it is appropriate to execute the braking control method disclosed in this application.

[0045] When the activation condition is not satisfied, in sub-step S130 , the hydraulic pressure will be maintained equal to the brake request pressure. That is, the brake control method disclosed in this application will not be executed, and the vehicle will be braked according to the traditional hydraulic braking method.

[0046] After the brake control function is activated, the brake control method of the present application proceeds to step S200, which involves obtaining a specific slope value. In one embodiment, the specific slope value refers to the precise value of the slope of the slope on which the vehicle is located. The specific slope value can be calculated using one or more of the following parameters: vehicle acceleration, wheel angular deceleration, wheel pitch angular velocity, etc. In one embodiment, vehicle acceleration can be obtained based on data from an accelerometer. In one embodiment, wheel pitch angular velocity can be obtained based on data from a suspension displacement sensor. For example, the specific slope value can be used to determine whether the slope the vehicle is on is uphill or downhill, and to select different control strategies based on different slope conditions. In one embodiment, the specific slope value can be calculated in real time by a vehicle computer system or vehicle control system, and the brake control method of the present application includes obtaining the specific slope value from the vehicle computer system or vehicle control system. It will be readily understood that the parameters described in this step, such as vehicle acceleration, wheel angular deceleration, and wheel pitch angular velocity, can be the real-time vehicle acceleration, wheel angular deceleration, and wheel pitch angular velocity read during the execution of step S200.

[0047] Step S300 involves planning control targets. In one embodiment, the control targets are planned based on slope-specific values. In one embodiment, the control targets may include a target for motor torque and a target for hydraulic pressure. In one embodiment, the target for hydraulic pressure may be a hydraulic pressure lower than the driver's requested pressure, and the target for motor torque may be a positive motor torque.

[0048] Step S400 involves adjusting the motor torque and hydraulic pressure to reduce vehicle deceleration. In step S400, the hydraulic pressure can be adjusted to be less than the brake request pressure, and the motor torque is set to positive. The reduction in hydraulic pressure reduces vehicle deceleration to a first level, and the positive motor torque further reduces vehicle deceleration to a second or predetermined level. These cumulative deceleration reductions occur simultaneously. Looking solely at vehicle deceleration, during the execution of step S400, vehicle deceleration gradually decreases from a relatively high level to a relatively low, predetermined level. It should be noted that when the hydraulic pressure is equal to the driver's request pressure, the vehicle will experience a relatively high deceleration. After reducing the hydraulic pressure and applying positive motor torque, the vehicle will experience a relatively low deceleration, which can be the second or predetermined level. Step S400 is described in detail below. In one embodiment, step S400 can be performed immediately after the preceding steps are completed. In one embodiment, the adjustment of hydraulic pressure and motor torque can be performed for at least a certain period of time during the execution of step S400.

[0049] For example, the total brake pressure or brake request pressure can be expressed as a controlled deceleration rate and converted into a target for the motor torque and a target for the hydraulic pressure. It should be noted that even under the dual effects of reduced hydraulic pressure and the application of positive motor torque, the vehicle deceleration remains greater than zero. In other words, the vehicle remains in a deceleration or braking state. When the braking control method of the present application is used, the vehicle deceleration in the final stage of the vehicle braking to a stop will be significantly less than the vehicle deceleration in conventional braking control methods. In conventional braking methods, when the hydraulic pressure equals the driver's requested pressure, the vehicle will experience a deceleration of approximately 0.05g. In one embodiment of the present application, after reducing the hydraulic pressure and applying positive motor torque, the vehicle will experience a deceleration of approximately 0.01g. In other words, the second level or predetermined level of deceleration can be approximately 0.01g, and the second level or predetermined level of deceleration is significantly less than the deceleration in conventional braking methods.

[0050] Regarding hydraulic pressure, the hydraulic pressure can be generated according to a control target. In one embodiment, controlling the hydraulic pressure may include generating an optimal wheel angular deceleration target, a target hydraulic pressure, etc., and performing brake pressure feedforward control and closed-loop feedback control based on the above targets.

[0051] Regarding motor torque, it can be controlled synchronously with hydraulic pressure. For example, motor torque can be calculated based on one or more of the following parameters: vehicle speed, specific slope value, wheel angular deceleration, etc. In one embodiment, controlling motor torque can include generating a target torque. It will be readily understood that the parameters described in this step, such as vehicle speed, specific slope value, and wheel angular deceleration, can be a series of real-time vehicle speeds, specific slope values, and wheel angular decelerations read during step S400.

[0052] By reducing hydraulic pressure and providing positive motor torque, the braking control method of the present application can effectively reduce the vehicle's deceleration at the end of the braking process, reducing the impact caused by the larger deceleration when the vehicle approaches a stop, thereby effectively improving the pitch and nod phenomenon before the vehicle brakes to a stop. In one embodiment, the braking control method of the present application can effectively improve the braking experience of the vehicle during low-speed conditions.

[0053] In one embodiment, the braking control method of the present application may further include step S700. In step S700, after the wheels stop, the hydraulic pressure is adjusted to be equal to the braking request pressure, and the motor torque is adjusted to zero. In step S700, the vehicle stops smoothly.

[0054] In one embodiment, the braking control method of the present application may further include step S500 and step S600. Step S500 and step S600 may be started after step S100 is executed, and executed in parallel with steps S200, S300 and S400. In one embodiment, step S500 includes safety risk monitoring. Specifically, after the braking control function is activated, the braking control method of the present application will continuously monitor one or more vehicle operating parameters. Such vehicle operating parameters may include, but are not limited to: the travel of the driving pedal and the brake pedal, the direction of wheel travel, the angular deceleration of the wheel, the vehicle speed, etc. In one embodiment, monitoring the vehicle operating parameters includes monitoring the risk of slipping.

[0055] In step S600, one embodiment of the brake control method of the present application determines whether a safety risk exists. If a safety risk is determined to exist, the brake control method of the present application implements countermeasures. In one embodiment, the countermeasures may include adjusting the hydraulic pressure to equal the brake request pressure and adjusting the motor torque to zero. In other words, when a safety risk is determined to exist, the hydraulic pressure and motor torque adjustments involved in the brake control method of the present application are canceled, and the conventional brake control strategy is restored. In one embodiment, the countermeasures may include: when a risk of vehicle rollover is detected while descending a slope or in a downhill state, the positive torque output of the motor torque may be reduced. If the risk of rollover still persists, the hydraulic pressure may be restored to the brake request pressure to ensure safe braking of the vehicle. When a risk of vehicle rollover is detected while ascending a slope or in an uphill state, the positive torque output of the motor torque may be increased. If the risk of rollover still persists, the hydraulic pressure may be restored to the brake request pressure to ensure safe braking of the vehicle.

[0056] Figure 3 illustrates the changes in various parameters during the braking process of an embodiment of a vehicle of the present application. The horizontal axis of Figure 3 represents time, and the vertical axis includes coordinates of multiple sets of different parameters. Figure 3 illustrates, from top to bottom: line L1, which illustrates the activation state of an embodiment of the braking control method according to the present application; line L2, which represents vehicle speed; line L3, which represents brake request pressure; line L4, which represents the hydraulic pressure that changes during the execution of step S400; and line L5, which represents the motor torque that changes during the execution of step S400.

[0057] As shown in FIG. 3 , on the left side of time point T0 , the vehicle is traveling normally, the brake request pressure is zero, and the vehicle has a predetermined speed.

[0058] At time T0, the driver or the automated driving system may issue a braking request, such as by depressing the brake pedal. In one embodiment, the braking request may also originate from the automated driving system. Line L3 begins to rise continuously until it reaches the brake request pressure P1. For conventional braking, line L3 remains at the brake request pressure P1 until the vehicle stops, the driver releases the brake pedal, or the automated driving system ceases issuing braking requests.

[0059] To the right of time point T0, the brake control method of the present application is executed. At time point T1, when the monitored vehicle speed is equal to the target activation speed V1, the brake control function is activated and steps S200 to S700 are executed. Specifically, step S400 is executed between time points T1 and T4, and step S700 is executed between time points T4 and T5. Furthermore, the brake control function is active between time points T1 and T5, corresponding to the protruding portion of line L1.

[0060] The hydraulic pressure change represented by line L4 successively goes through: a hydraulic pressure reduction stage, a hydraulic pressure maintenance stage, and a hydraulic pressure increase stage. The hydraulic pressure reduction stage is between time point T1 and time point T3. The hydraulic pressure first starts to decrease from being equal to the brake request pressure. In one embodiment, the reduction of the hydraulic pressure can be carried out along a curve. In one embodiment, the hydraulic pressure can change toward a target for the hydraulic pressure, or in other words, change in accordance with the control target. The hydraulic pressure maintenance stage is between time point T3 and time point T4. The hydraulic pressure can be maintained at a first value in this stage. The hydraulic pressure recovery stage is between time point T4 and time point T5. The hydraulic pressure continues to increase in this stage, for example, along a straight line, until the hydraulic pressure is equal to the brake request pressure P1.

[0061] The motor torque change represented by line L5 successively goes through: a motor torque growth phase, a motor torque maintenance phase and a motor torque reduction phase. The motor torque growth phase is between time point T1 and time point T2. During this process, the motor torque increases from zero, for example, along a curve, for example, toward the target for the motor torque or in accordance with the control target. The motor torque maintenance phase is between time point T2 and time point T4. The motor torque can be maintained at a second value during this phase. In the motor torque reduction phase, the motor torque can be reduced from the second value to zero. In the illustrated embodiment, line L5 is in the form of a curve in the motor torque growth phase and the motor torque reduction phase. According to actual needs, line L5 can also be in the form of a straight line in the motor torque growth phase and the motor torque reduction phase.

[0062] In the illustrated embodiment, time point T2 and time point T3 are separated. Therefore, the start time of the motor torque maintenance phase can be earlier than the start time of the hydraulic pressure maintenance phase. Such an arrangement allows the motor torque compensation to reach a stable value earlier than the hydraulic pressure, ensuring that the positive torque from the motor will not be too high, avoiding potential safety issues. In one embodiment, time point T2 and time point T3 can also be roughly overlapping. Therefore, starting from time point T1, the motor torque and hydraulic pressure can be adjusted synchronously. In addition, the start time of the motor torque reduction phase and the start time of the hydraulic pressure increase phase can be corresponding, as shown in Figure 3 by time point T4. The time point when the vehicle speed is reduced to zero can be earlier than, equal to, or later than time point T4. In the illustrated embodiment, the time point when the vehicle speed is reduced to zero is later than time point T4. In one embodiment, starting from time point T4, the motor torque and hydraulic pressure can be adjusted synchronously.

[0063] Referring to Figure 4, a schematic diagram of a braking control system 100 according to one aspect of the present application is shown. In one embodiment, braking control system 100 may include, among others, a memory 110, a processor 120, and a computer program 130. Memory 110 may be a non-volatile memory such as a flash memory, a ROM, a hard drive, a magnetic disk, or an optical disk. Computer program 130 may be stored in memory 110 and executed on processor 120. The execution of computer program 130 implements a braking control method according to one or more embodiments of the present application. For a description of this system, reference may be made to the above description of the braking control method, and will not be repeated here.

[0064] In addition, the present application also relates to a computer-readable storage medium for implementing one or more embodiments of the present application and for executing the braking control method described herein in a vehicle. The computer-readable storage medium mentioned herein includes various types of computer storage media, which can be any available medium that can be accessed by a general-purpose or special-purpose computer. For example, the computer-readable storage medium may include RAM, ROM, EPROM, E2PROM, registers, hard disks, removable hard disks, CD-ROMs or other optical disk storages, magnetic disk storages or other magnetic storage devices, or any other temporary or non-temporary medium that can be used to carry or store desired program code units in the form of instructions or data structures and can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. The description of the computer-readable storage medium according to the present application can refer to the explanation of the method of the present application, and no further details will be given.

[0065] Finally, the present application also provides a vehicle including a brake control system according to one or more embodiments of the present application. The description of the battery swap station according to the present application can refer to the explanation of the method of the present application, which will not be repeated here.

[0066] The braking control method, system, medium and vehicle of the present application have the advantages of simplicity, reliability, ease of implementation and convenience of use, and can provide improved braking force feedback and reduce the needs of adapting to different vehicle models and working conditions.

[0067] This specification discloses the present application with reference to the accompanying drawings and also enables those skilled in the art to practice the present application, including making and using any system or systems, selecting suitable materials, and using any combined methods. The scope of the present application is defined by the claimed technical solution and includes other examples that occur to those skilled in the art. As long as such other examples include structural elements that are not different from the literal language of the claimed technical solution, or such other examples include equivalent structural elements that are not substantially different from the literal language of the claimed technical solution, such other examples should be deemed to be within the scope of protection determined by the claimed technical solution.

Claims

1. A braking control method, characterized in that: The vehicle performs the following steps: S100: selectively activating a brake control function during vehicle braking; S200: Obtaining specific slope values; S300: Planning control objectives; and S400: adjusting the motor torque and the hydraulic pressure according to the control target so as to reduce the deceleration of the vehicle; The motor torque is the driving torque output by the driving motor and is positive, the hydraulic pressure is the braking pressure of the vehicle hydraulic braking system, and the hydraulic pressure is set to be less than the braking request pressure for at least a certain time during step S400.

2. The braking control method according to claim 1, characterized in that: Step S100 includes a sub-step S120 : activating the brake control function when the vehicle speed is less than or equal to the target activation speed.

3. The braking control method according to claim 2, characterized in that: The target activation vehicle speed is calculated by a real-time value of the wheel angular deceleration, and the target activation vehicle speed is between 3 and 7 kilometers per hour.

4. The braking control method according to claim 2, wherein: Step S100 also includes sub-step S110: before the sub-step S120, determine whether the activation condition is met; wherein, whether the activation condition is met is determined by the real-time values ​​of one or more of the following parameters: vehicle movement direction, lateral acceleration, longitudinal deceleration, vehicle speed, preliminary slope value, and vehicle safety function.

5. The braking control method according to claim 4, characterized in that: The step S100 further includes a sub-step S130 of maintaining the hydraulic pressure equal to the brake request pressure when the activation condition is not satisfied.

6. The brake control method according to claim 1, characterized in that: In step S200, the specific value of the slope is calculated by the real-time value of one or more of the following parameters: vehicle acceleration, wheel angular deceleration, and vehicle pitch angular velocity; in step S300, the control target is planned based on the specific value of the slope and includes: a target for the motor torque and a target for the hydraulic pressure.

7. The brake control method according to claim 1, characterized in that: In step S400, the hydraulic pressure is adjusted to be less than the brake request pressure for at least a certain period of time, and at the same time, a positive motor torque is applied to reduce the deceleration to a predetermined level; wherein the positive motor torque tends to drive the vehicle forward in the longitudinal direction, and the deceleration is always maintained greater than zero.

8. The brake control method according to claim 7, characterized in that: The motor torque is calculated based on real-time values ​​of one or more of the following parameters: vehicle speed, grade-specific value, and wheel angular deceleration.

9. The braking control method according to claim 7, characterized in that: In step S400, the hydraulic pressure goes through the following stages: a hydraulic pressure reduction phase, wherein the hydraulic pressure continues to decrease starting from being equal to the brake request pressure; and a hydraulic pressure maintaining phase, wherein the hydraulic pressure is maintained at a first value; and The motor torque goes through the following phases: a motor torque increasing phase, wherein the motor torque continues to increase; and The motor torque maintaining phase is as follows: the motor torque is maintained at a second value.

10. The brake control method according to claim 9, characterized in that: The start time of the motor torque reduction phase corresponds to the start time of the hydraulic pressure increase phase and is earlier than the time when the vehicle completely stops; and wherein the start time of the motor torque maintenance phase is earlier than the start time of the hydraulic pressure maintenance phase.

Images