Brake control method and device, storage medium and vehicle

Abstract

The invention provides a brake control method and device, a storage medium and a vehicle. The method comprises the steps that under the condition that the vehicle is in a downhill driving state, when it is detected that a brake pedal is stepped down, a target ramp type and the whole vehicle brake demand torque are determined; determining a target motor braking proportion corresponding to the target ramp type; according to the target motor braking proportion, the whole vehicle braking demand torque is distributed, and the target motor braking torque and the target hydraulic braking torque are obtained; and the motor braking system is controlled to output the target motor braking torque, and the hydraulic braking system is controlled to output the target hydraulic braking torque. The proportions of motor braking and hydraulic braking in the whole vehicle braking demand torque are distributed according to the ramp type, the braking energy recovery grade is divided according to the ramp type, the energy recovery function can be fully utilized in the braking process of the vehicle, enough braking force is guaranteed, and the braking efficiency of the vehicle is improved. And the abrasion of brake components in the hydraulic brake system can be reduced.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a braking control method, device, storage medium and vehicle. Background Art

[0002] With the increasing popularity of new energy electric vehicles and hybrid vehicles, in order to improve the energy utilization rate of the whole vehicle, most vehicles are equipped with a braking energy recovery system. When the driver releases the accelerator pedal and steps on the brake pedal, the brake components will dynamically distribute energy recovery braking and hydraulic braking according to the vehicle status and the driver's braking request. When there is energy recovery braking, the drive motor plays a role, outputting negative torque to achieve motor power generation, and storing electrical energy in the battery to improve the vehicle's endurance.

[0003] At present, the method of determining the braking energy recovery ratio used by vehicles is mostly based on the brake pedal travel size and driving parameters such as vehicle speed. When the vehicle is on a downhill road for a long time, the hydraulic braking weight is too large, which can easily cause the brake disc to heat up, thereby causing the friction coefficient between the brake disc and the friction plate to decrease, affecting the vehicle's braking performance. In addition, long-term uninterrupted hydraulic braking shortens the service life of components. In addition, too much kinetic energy and potential energy are wasted in converting into heat energy, and energy is not effectively utilized. Summary of the invention

[0004] The embodiments of the present application provide a braking control method, device, storage medium and vehicle to solve the problem of energy waste caused by unreasonable distribution of hydraulic braking and motor braking when the vehicle is in a downhill condition for a long time.

[0005] In a first aspect, an embodiment of the present application provides a braking control method, the method comprising:

[0006] When the vehicle is in a downhill driving state, when it is detected that the brake pedal is stepped on, determining the target slope type corresponding to the slope on which the vehicle is located and the braking torque required for the whole vehicle;

[0007] Determining a target motor braking ratio corresponding to the target ramp type;

[0008] According to the target motor braking ratio, the vehicle braking demand torque is distributed to obtain a target motor braking torque and a target hydraulic braking torque;

[0009] Wherein, the ratio of the target motor braking torque to the vehicle braking requirement torque is the target motor braking ratio;

[0010] The motor brake system is controlled to output the target motor braking torque and the hydraulic brake system is controlled to output the target hydraulic braking torque.

[0011] In a second aspect, an embodiment of the present application further provides a braking control device, the device comprising:

[0012] A first determination module is used to determine a target slope type corresponding to the slope on which the vehicle is located and a braking torque requirement of the whole vehicle when it is detected that the brake pedal is stepped on when the vehicle is in a downhill driving state;

[0013] A second determination module is used to determine a target motor braking ratio corresponding to the target ramp type;

[0014] A first allocation module is used to allocate the vehicle braking demand torque according to the target motor braking ratio to obtain a target motor braking torque and a target hydraulic braking torque;

[0015] Wherein, the ratio of the target motor braking torque to the vehicle braking requirement torque is the target motor braking ratio;

[0016] The first control module is used to control the motor brake system to output the target motor braking torque and the hydraulic brake system to output the target hydraulic braking torque.

[0017] In a third aspect, an embodiment of the present application further provides an electronic device, which includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the above-mentioned braking control method when executed by the processor.

[0018] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the above-mentioned braking control method is implemented.

[0019] In a fifth aspect, an embodiment of the present application further provides a vehicle, which includes the above-mentioned braking control device.

[0020] The embodiments of the present application include at least the following technical effects:

[0021] The technical solution of the embodiment of the present application is to determine the target motor braking ratio that matches the target slope type on which the vehicle is located when the vehicle is in a downhill state and the brake pedal is pressed, and allocate the vehicle braking demand torque according to the target braking ratio to obtain the target motor braking torque and the target hydraulic braking torque, so that the motor braking system outputs the target motor braking torque and the hydraulic braking system outputs the target hydraulic braking torque. The present application can allocate the ratio of motor braking and hydraulic braking in the vehicle braking demand torque according to the slope type, and realizes the division of braking energy recovery levels according to the slope type. During the braking process, the vehicle can fully utilize the energy recovery function and ensure sufficient braking force, and can also reduce the wear of braking components in the hydraulic braking system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0023] Figure 1 It is one of the flowcharts of the braking control method provided in the embodiment of the present application;

[0024] Figure 2 This is the second flow chart of the braking control method provided in the embodiment of the present application;

[0025] Figure 3 This is the third flow chart of the braking control method provided in the embodiment of the present application;

[0026] Figure 4 is a schematic structural diagram of a brake control device provided in an embodiment of the present application;

[0027] Figure 5 A block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0029] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present application. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0030] In the various embodiments of the present application, it should be understood that the size of the serial numbers of the following processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0031] In the related technologies, the way to determine the braking energy recovery ratio used by new energy electric vehicles and hybrid electric vehicles is mostly based on the brake pedal travel size and driving parameters such as vehicle speed, without considering the actual road conditions. Therefore, when the vehicle is on a downhill road for a long time, the distribution ratio of hydraulic braking and motor braking will be unreasonable, making the hydraulic braking weight too large, which is easy to cause high temperature of the brake disc, and then cause the friction coefficient between the brake disc and the friction plate to decrease, affecting the vehicle's braking performance. In addition, long-term uninterrupted hydraulic braking shortens the service life of components. In addition, too much kinetic energy and potential energy are wasted in converting into heat energy, and energy is not effectively utilized.

[0032] Based on this, the inventor has proposed a braking control solution that can solve the problem of brake disc overheating and energy waste caused by unreasonable distribution of hydraulic braking and motor braking when the vehicle is on a downhill road for a long time. The technical solution of this application is described below through specific embodiments.

[0033] like Figure 1 As shown, an embodiment of the present application provides a braking control method, the method comprising:

[0034] Step 101: When a vehicle is in a downhill driving state and it is detected that the brake pedal is stepped on, a target slope type corresponding to the slope where the vehicle is located and a required braking torque of the whole vehicle are determined.

[0035] The braking control method provided in the embodiment of the present application is applied to an electronic brake controller, wherein the electronic control unit in the electronic brake controller can accurately identify the driver's braking needs and accurately control the braking system by virtue of its computing advantages and the advantages of real-time interaction with sensors and vehicle components, so as to improve the braking performance and stability of the vehicle. The braking system here includes a hydraulic braking system and a motor braking system.

[0036] The electronic brake controller can detect whether the brake pedal is pressed when the vehicle is in a downhill driving state, or it can also detect whether the vehicle is in a downhill driving state when the brake pedal is detected to be pressed. That is, the electronic brake controller will judge the following two conditions: the first condition is whether the vehicle is in a downhill driving state, and the second condition is whether the brake pedal is pressed. When these two conditions are met at the same time, the electronic brake controller determines the slope type corresponding to the slope where the vehicle is located, obtains the target slope type, and determines the required braking torque of the whole vehicle based on parameters such as the brake pedal travel.

[0037] Optionally, multiple ramp types can be pre-stored in the electronic brake controller. Then, when determining the ramp type corresponding to the ramp on which the vehicle is located, the target ramp type corresponding to the current ramp can be determined from the multiple pre-stored ramp types based on parameters such as the slope corresponding to the ramp on which the vehicle is located and the driving time of the vehicle at different slopes.

[0038] It should be noted that both hydraulic brake systems and motor brake systems can be installed on electric vehicles and hybrid vehicles. The motor brake system mainly includes components such as drive motor, motor controller, inverter and battery. The hydraulic brake system is similar to that of traditional fuel vehicles, including brake pedal, brake master cylinder, brake pipe, brake wheel cylinder and brake disc.

[0039] It should be further explained that the electronic brake controller can determine the distribution ratio of motor braking and hydraulic braking according to various factors such as pedal stroke, vehicle speed, battery status, etc. when the driver steps on the brake pedal, that is, determine the proportion of motor braking and the proportion of hydraulic braking. When the motor brake system is working, the drive motor is converted from the driving mode to the power generation mode, the wheel drives the motor to rotate, and the rotor of the motor rotates in the magnetic field to cut the magnetic flux lines, generating an induced electromotive force according to the law of electromagnetic induction, thereby converting the mechanical energy of the vehicle into electrical energy. The generated alternating current is converted into direct current through an inverter and then stored in the vehicle's battery. The energy recovery process can increase the vehicle's cruising range. The recovered electrical energy can be reused to drive the motor during the subsequent driving process of the vehicle, reducing the energy consumption of the battery. In addition, since the motor brake system shares part of the braking task, the frequency of use of the hydraulic brake system is reduced, thereby extending the service life of hydraulic brake components (such as brake pads, brake discs, etc.). This not only reduces the maintenance cost of the vehicle, but also improves the reliability of the braking system.

[0040] Step 102: Determine a target motor braking ratio corresponding to the target ramp type.

[0041] After determining the target ramp type, the target motor braking ratio corresponding to the target ramp type can be determined. The target motor braking ratio is the ratio of the motor braking torque provided by the motor braking system to the total required braking torque, and the part of the total required braking torque other than the motor braking torque is provided by the hydraulic braking system.

[0042] The correspondence between the ramp type and the motor braking ratio is pre-stored in the electronic brake controller. Different ramp types correspond to different motor braking ratios. When determining the target motor braking ratio corresponding to the target ramp type, it includes:

[0043] Obtaining a pre-stored correspondence between the ramp type and the motor braking ratio;

[0044] The target motor braking ratio is determined according to the corresponding relationship and the target ramp type.

[0045] Specifically, the correspondence between the ramp type and the motor braking ratio can be pre-stored in the electronic brake controller, or stored in other storage locations. When it is necessary to determine the target motor braking ratio corresponding to the current ramp type, i.e., the target ramp type, the electronic brake controller obtains the pre-stored correspondence between the ramp type and the motor braking ratio, and then determines the target motor braking ratio that matches the target ramp type based on the correspondence.

[0046] In the above implementation process, the target motor braking ratio is determined by the target ramp type, which can maximize energy recovery, reduce the wear of hydraulic brake components, increase the vehicle's cruising range, and avoid vehicle failure due to excessive use of a single braking system, thereby improving braking safety and thus driving safety.

[0047] Step 103: distribute the vehicle braking demand torque according to the target motor braking ratio to obtain a target motor braking torque and a target hydraulic braking torque; wherein the ratio of the target motor braking torque to the vehicle braking demand torque is the target motor braking ratio.

[0048] After determining the target motor braking ratio, the vehicle braking demand torque is allocated according to the target motor braking ratio to obtain the target motor braking torque and target hydraulic braking torque.

[0049] Among them, the ratio of the target electric motor braking torque to the vehicle braking requirement torque is the target motor braking ratio, and the sum of the target electric motor braking torque and the target hydraulic braking torque is the vehicle braking requirement torque.

[0050] Step 104 : Control the motor brake system to output the target motor braking torque and the hydraulic brake system to output the target hydraulic braking torque.

[0051] After the target electric motor braking torque is obtained, the motor braking system is controlled to output the target electric motor braking torque. After the target hydraulic braking torque is obtained, the hydraulic braking system is controlled to output the target hydraulic braking torque.

[0052] In an embodiment of the present application, when the vehicle is in a downhill state and the brake pedal is pressed, a target motor braking ratio that matches the target slope type on which the vehicle is located is determined, and the braking demand torque of the whole vehicle is allocated according to the target braking ratio, so as to obtain a target motor braking torque and a target hydraulic braking torque, so that the motor braking system outputs the target motor braking torque and the hydraulic braking system outputs the target hydraulic braking torque. The present application can allocate the ratio of motor braking and hydraulic braking in the braking demand torque of the whole vehicle according to the slope type, and realizes the division of braking energy recovery levels according to the slope type. During the braking process, the vehicle can fully utilize the energy recovery function and ensure sufficient braking force, and can also reduce the wear of braking components in the hydraulic braking system.

[0053] Considering that during vehicle driving, if the road slope changes slightly and the slope does not exceed the slope range corresponding to the current ramp type, that is, when the ramp type does not change, if the target motor rotation ratio is always used to distribute the braking torque, the braking energy recovery rate may be reduced, or the deceleration fluctuation may be large due to the excessive braking energy recovery rate. In an optional embodiment of the present application, after controlling the motor brake system to output the target motor braking torque and the hydraulic brake system to output the target hydraulic braking torque, the method further includes:

[0054] Periodically obtain the braking energy recovery rate and deceleration fluctuation value;

[0055] Determine the motor braking ratio adjustment value according to the current braking energy recovery utilization rate and the current deceleration fluctuation value obtained in the current cycle, and the historical braking energy recovery utilization rate obtained in the previous cycle of the current cycle;

[0056] According to the motor braking ratio adjustment value, the motor braking ratio corresponding to the current cycle is adjusted to obtain the adjusted motor braking ratio;

[0057] According to the adjusted motor braking proportion, the required braking torque of the whole vehicle is distributed to obtain the adjusted motor braking torque and the adjusted hydraulic braking torque;

[0058] The motor brake system is controlled to output the adjusted motor braking torque, and the hydraulic brake system is controlled to output the adjusted hydraulic braking torque.

[0059] In specific implementation, a detection cycle can be pre-set, and the braking energy recovery rate and the deceleration fluctuation value can be periodically detected according to the preset detection cycle. And according to the braking energy recovery rate and the deceleration fluctuation value, it is determined whether to adjust the motor braking ratio to obtain the motor braking ratio adjustment value.

[0060] The deceleration fluctuation value can be determined by the vehicle deceleration data collected in real time by the acceleration sensor. Specifically, the deceleration fluctuation value can be the standard deviation calculated based on the deceleration data. The standard deviation can be used to quantify the degree of deceleration fluctuation. The standard deviation reflects the degree of discreteness of the data. The larger the standard deviation, the greater the deceleration fluctuation.

[0061] Among them, when obtaining the braking energy recovery utilization rate, it includes:

[0062] Obtaining actual recovered energy value and recoverable energy value;

[0063] The braking energy recovery utilization rate is determined according to the actual recovered energy value and the recoverable energy value.

[0064] Specifically, when each detection time arrives, the actual recovery energy value and the recoverable energy value are calculated. The actual recovery energy value can be calculated based on the average power generation of the motor and the braking recovery time. The recoverable energy value can be calculated based on the kinetic energy and gravitational potential energy of the vehicle.

[0065] Then, the ratio of the actual energy recovery value to the recoverable energy value is determined as the braking energy recovery utilization rate.

[0066] In the above implementation process, by calculating the braking energy recovery utilization rate, the current braking energy recovery status of the vehicle can be determined, thereby effectively utilizing the energy in the braking process and reducing energy waste.

[0067] Specifically, the motor braking ratio adjustment value is determined according to the current braking energy recovery utilization rate and the current deceleration fluctuation value obtained in the current cycle, and the historical braking energy recovery utilization rate obtained in the cycle before the current cycle.

[0068] Then, according to the motor braking ratio adjustment value, the motor braking ratio corresponding to the current cycle is adjusted to obtain the adjusted motor braking ratio. Then, in the next cycle, according to the adjusted motor braking ratio, the required braking torque of the whole vehicle is allocated to obtain the adjusted electric braking torque and the adjusted hydraulic braking torque; then the motor braking system is controlled to output the adjusted electric braking torque, and the hydraulic braking system is controlled to output the adjusted hydraulic braking torque.

[0069] In the specific implementation process, when the electronic brake controller determines that the vehicle is on the target ramp type, the target motor braking ratio corresponding to the target ramp type is used to distribute the braking torque. When the ramp type does not change, the motor braking ratio adjustment value is determined by periodically detecting the braking energy recovery utilization rate and combining the braking energy recovery utilization rate detected in the current cycle, the braking energy recovery utilization rate in the previous cycle, and the deceleration fluctuation value that can characterize the deceleration fluctuation.

[0070] Among them, the motor braking ratio adjustment value at least includes zero, a first preset value and a second preset value, the first preset value is positive, and the second preset value is negative. Then, according to the motor braking ratio adjustment value, the motor braking ratio corresponding to the current cycle is adjusted to obtain the adjusted motor braking ratio. If the motor braking ratio adjustment value is zero, the motor braking ratio corresponding to the current cycle is not adjusted, and the motor braking ratio corresponding to the current cycle continues to be used to distribute the braking torque in the next cycle; if the motor braking ratio adjustment value is the first preset value, the motor braking ratio corresponding to the current cycle is increased by the first preset value, then the adjusted motor braking ratio is greater than the motor braking ratio corresponding to the current cycle, and the adjusted motor braking ratio is used to distribute the braking torque in the next cycle; if the motor braking ratio adjustment value is the second preset value, the motor braking ratio corresponding to the current cycle is reduced by the absolute value of the second preset value, then the adjusted motor braking ratio is less than the motor braking ratio corresponding to the current cycle, and the adjusted motor braking ratio is used to distribute the braking torque in the next cycle.

[0071] After obtaining the adjusted motor braking ratio, the required braking torque of the whole vehicle will be distributed according to the adjusted motor braking ratio to obtain the adjusted electric motor braking torque and the adjusted hydraulic braking torque, and the motor braking system will be controlled to output the adjusted electric motor braking torque, and the hydraulic braking system will be controlled to output the adjusted hydraulic braking torque. It should be noted that the required braking torque of the whole vehicle is determined in real time by the electronic brake controller based on parameters such as the brake pedal travel.

[0072] The above implementation scheme of the present application detects the braking energy recovery rate and the deceleration fluctuation to determine the motor braking ratio adjustment value, and adjusts the motor braking ratio, thereby achieving fine-tuning of the motor braking ratio when the slope type remains unchanged, thereby further saving energy and improving the driving experience.

[0073] The following is an introduction to the process of determining the motor braking ratio adjustment value. In an optional embodiment of the present application, the motor braking ratio adjustment value is determined based on the current braking energy recovery utilization rate and the current deceleration fluctuation value obtained in the current cycle, and the historical braking energy recovery utilization rate obtained in the previous cycle of the current cycle, including:

[0074] Calculating the difference between the current braking energy recovery utilization rate and the historical braking energy recovery utilization rate to obtain a braking energy recovery utilization rate change value;

[0075] When the braking energy recovery utilization rate change value is less than a first threshold, determining the motor braking proportion adjustment value to be a first preset value; wherein the first threshold is less than or equal to zero, and the first preset value is greater than zero;

[0076] When the braking energy recovery utilization rate change value is greater than a second threshold, determining whether the deceleration fluctuation value is greater than a preset fluctuation threshold; wherein the second threshold is greater than or equal to zero;

[0077] When the deceleration fluctuation value is greater than the preset fluctuation threshold, determining the motor braking proportion adjustment value to be a second preset value, and the second preset value is less than zero;

[0078] When the deceleration fluctuation value is less than or equal to the preset fluctuation threshold, determining that the motor braking proportion adjustment value is zero;

[0079] When the braking energy recovery utilization rate change value is greater than or equal to the first threshold and the braking energy recovery utilization rate change value is less than or equal to the second threshold, it is determined that the motor braking proportion adjustment value is zero.

[0080] In a specific implementation, the determined motor braking proportion adjustment value is one of a first preset value, a second preset value and zero, wherein the first preset value is a positive value and the second preset value is a negative value.

[0081] When determining the motor braking ratio adjustment value, first calculate the difference between the current braking energy recovery rate and the braking energy recovery rate collected in the previous cycle, that is, the historical braking energy recovery rate, to obtain the braking energy recovery rate change value. When the braking energy recovery rate change value is positive, it indicates that the current braking energy recovery rate is higher than the historical energy recovery rate. When the braking energy recovery rate change value is negative, it indicates that the current braking energy recovery rate is lower than the historical energy recovery rate.

[0082] After obtaining the change value of the braking energy recovery utilization rate, it is compared with the first threshold and the second threshold, where the first threshold is less than or equal to zero and the second threshold is greater than or equal to zero. According to the comparison result, it is divided into the following three cases:

[0083] The first case is that the change value of the braking energy recovery rate is less than the first threshold. At this time, the reduction of the current braking energy recovery rate compared with the historical energy recovery rate exceeds the absolute value of the first threshold. At this time, in order to ensure the braking energy recovery rate, the motor braking ratio needs to be increased.

[0084] The second case is that the change value of the braking energy recovery rate is greater than the second threshold. At this time, the increase in the current braking energy recovery rate compared with the historical energy recovery rate exceeds the second threshold. At this time, it is necessary to further determine whether the deceleration fluctuation value is greater than the preset fluctuation threshold to determine whether the vehicle's deceleration has excessive fluctuations caused by excessive motor torque. If the deceleration fluctuation value is greater than the preset fluctuation threshold, it indicates that the current vehicle's deceleration has excessive fluctuations. At this time, in order to control the deceleration fluctuation, it is necessary to reduce the motor braking ratio, that is, set the motor braking ratio adjustment value to the second preset value. Since the second preset value is less than zero, the motor braking ratio obtained by the motor braking ratio adjustment value will be reduced, thereby reducing the deceleration fluctuation to improve the driving experience. In addition, if the deceleration fluctuation value is less than or equal to the preset fluctuation threshold, that is, the degree of deceleration fluctuation of the vehicle is not large, at this time, the motor braking ratio can be adjusted without adjustment, that is, the motor braking ratio adjustment value is zero.

[0085] The third case is that the braking energy recovery utilization rate change value is between the first threshold and the second threshold, that is, the braking energy recovery utilization rate change value is greater than or equal to the first threshold and the braking energy recovery utilization rate change value is less than or equal to the second threshold. At this time, the motor braking ratio may not be adjusted, that is, the motor braking ratio adjustment value is zero.

[0086] The above implementation scheme of the present application, when determining the adjustment value of the motor braking ratio, fully considers the changes in the braking energy recovery utilization rate and the vehicle's deceleration fluctuations, and realizes dynamic adjustment of the motor braking ratio, so that the motor can recover energy under the most favorable conditions, avoid energy waste, and effectively extend the vehicle's cruising range. It can also improve the vehicle's braking stability, avoid large fluctuations in the vehicle's deceleration due to sudden changes in motor braking, and improve driving comfort.

[0087] like Figure 2 The figure shows a flow chart of the motor braking ratio fine-tuning process, including:

[0088] Step 201: In the current cycle, obtain the actual recovered energy value and the recoverable energy value.

[0089] Step 202: Determine the current braking energy recovery rate according to the actual recovery energy value and the recoverable energy value.

[0090] Step 203, compare the current braking energy recovery rate with the historical energy recovery rate. If it becomes larger, execute step 204; if it becomes smaller, execute step 206; if it does not change, the current cycle ends.

[0091] Step 204: determine whether the deceleration fluctuation value is greater than a preset fluctuation threshold. If yes, execute step 205; otherwise, the current cycle ends.

[0092] Step 205: Reduce the motor braking ratio.

[0093] Step 206: Increase the motor braking ratio.

[0094] Specifically, after the motor brake system is controlled to output the adjusted motor braking torque and the hydraulic brake system is controlled to output the adjusted hydraulic braking torque, when the type of the slope on which the vehicle is located has not changed, the motor braking ratio will be adjusted periodically according to the preset detection cycle. Each cycle can be regarded as a cycle. Among them, in the current cycle, the actual recovery energy value and the recoverable energy value are obtained, and the current braking energy recovery utilization rate corresponding to the current cycle is calculated, and then, by comparing the current braking energy recovery utilization rate with the historical energy recovery utilization rate, where the historical energy recovery utilization rate is the energy recovery utilization rate corresponding to the previous cycle. Here, the first threshold and the second threshold are set to zero. When the current braking energy recovery utilization rate is less than the historical energy recovery utilization rate, the motor braking ratio is increased. When the current braking energy recovery utilization rate is greater than the historical energy recovery utilization rate, it is further determined whether the deceleration fluctuation value is greater than the preset fluctuation threshold value. If it is greater, the motor braking ratio is reduced. If it is not greater, the current cycle ends. When the current braking recovery utilization rate is equal to the historical energy recovery utilization rate, the motor braking ratio is not adjusted in the current cycle.

[0095] How to determine the target ramp type is described below. In an optional embodiment of the present application, determining the target ramp type corresponding to the ramp on which the vehicle is located includes:

[0096] Determining a slope corresponding to the ramp on which the vehicle is located;

[0097] Determining a target slope range in which the slope is located from a plurality of slope ranges; wherein each slope range corresponds to two ramp types;

[0098] Determining a target time threshold corresponding to the target slope range, and a duration during which the slope of the vehicle is within the target slope range;

[0099] The target ramp type is determined according to the duration, the target time threshold and a preset time threshold.

[0100] Specifically, when determining the slope corresponding to the ramp on which the vehicle is located, the longitudinal acceleration in the direction of travel of the vehicle can be detected by an acceleration sensor installed on the vehicle, and then the slope of the ramp on which the vehicle is located can be calculated based on the detected longitudinal acceleration and gravity acceleration.

[0101] i=tanθ*100%=a / g*100%, wherein i is the slope, θ is the slope angle, a is the longitudinal acceleration, and g is the acceleration due to gravity.

[0102] In specific implementation, multiple slope ranges are stored in the electronic brake controller in advance, and two ramp types are set for each slope range. Different slope ranges also correspond to different time thresholds. Among them, multiple slope ranges can be divided into 2, 3 or more according to actual conditions and needs. For example, 0% to 15% can be divided into a slope range, 15% to 30% can be divided into a slope range, and 30% to 45% can be divided into a slope range, and then a corresponding time threshold is set for each slope range.

[0103] In this way, according to the specific value of the slope corresponding to the slope on which the vehicle is located, a target slope range corresponding to the slope can be determined from multiple pre-stored slope ranges, and a target time threshold corresponding to the target slope range can be obtained.

[0104] It should be noted that a preset time threshold is also stored in the electronic brake controller, and the preset time threshold is used to determine whether the slope on which the vehicle is located is a pothole slope.

[0105] When the target ramp range corresponding to the ramp where the vehicle is located is determined, the timing is started to obtain the duration of the slope being in the target ramp range. Then, the target ramp type is determined based on the duration, the target time threshold, and the preset time threshold. The preset time threshold here is

[0106] Wherein, determining the target ramp type according to the duration, the target time threshold and the preset time threshold includes:

[0107] When the duration is less than or equal to the preset time threshold, determining that the target ramp type is a pothole ramp type;

[0108] When the duration is greater than the preset time threshold and less than the target time threshold, determining that the target ramp type is a first ramp type corresponding to the target slope range;

[0109] When the duration is greater than the target time threshold, the target slope type is determined to be a second slope type corresponding to the target slope range.

[0110] It should be noted that each slope range corresponds to two ramp types, namely a first ramp type and a second ramp type.

[0111] In specific implementation, by comparing the duration and the preset time threshold, it is determined whether the target ramp type is a pothole ramp type. When the duration is less than or equal to the preset time threshold, the target ramp type is determined to be a pothole ramp type. When the duration is greater than the preset time threshold, it is determined that the target ramp type is not a pothole ramp type. The duration and the target time threshold are further compared. When the duration is less than the target time threshold, the target ramp type is determined to be the first ramp type corresponding to the target slope range. When the duration is greater than the target time threshold, the target ramp type is determined to be the second ramp type corresponding to the target slope range.

[0112] Specifically, for a pothole-type ramp, that is, the time for which the slope of the ramp is maintained in the same slope range is less than a preset time threshold, at this time, considering the grip of the wheels on the pothole-type road, therefore, for this type of ramp, a corresponding motor braking ratio can be set.

[0113] In addition, corresponding motor braking ratios are set for the two slope types corresponding to each slope range.

[0114] The above implementation scheme of the present application determines the target slope range and the target time threshold through the slope corresponding to the slope on which the vehicle is located and multiple predetermined slope ranges, and determines the target slope type corresponding to the slope on which the vehicle is located based on the duration that the slope of the slope on which the vehicle is located is within the target slope range, the target time threshold and the preset time threshold, so as to facilitate the subsequent determination of the corresponding target motor braking ratio according to the target ramp type, and realizes the division of braking energy recovery levels according to ramp types, so that the vehicle can fully utilize the energy recovery function and ensure sufficient braking force during braking, and can also reduce the wear of braking components in the hydraulic braking system.

[0115] like Figure 3As shown, it is a flow chart of the process of determining the type of ramp. First, the slope of the ramp where the vehicle is located is obtained. The slope can be calculated based on the gravity acceleration and the longitudinal acceleration collected by the acceleration sensor. The calculation method can be referred to the above embodiment, which will not be repeated here. The electronic brake controller stores multiple pre-set slope ranges. Here, three slope ranges are set as an example for introduction, namely the first slope range, the second slope range and the third slope range, wherein the first slope range corresponds to 0% to 15%, the second slope range corresponds to 15% to 30%, and the third slope range corresponds to 30% to 45%. By judging the slope threshold of the slope of the ramp where the vehicle is located, the slope range where the current slope is located can be determined. Further, after determining the slope range, determine the duration of the slope of the ramp where the vehicle is located in the current slope range, and determine whether the duration is greater than the preset time threshold. If it is less than the preset time threshold, it is determined that the type of the current ramp is a pothole ramp. If it is greater than the preset time threshold, it is further determined whether the duration is greater than the time threshold. It should be noted that different slope ranges correspond to different time thresholds, and each slope range corresponds to two types of ramps. The first slope range corresponds to the first time threshold, the second slope range corresponds to the second time threshold, and the third slope range corresponds to the third time threshold. The first slope range corresponds to the first ramp and the second ramp, the second slope range corresponds to the third ramp and the fourth ramp, and the third slope range corresponds to the fifth ramp and the sixth ramp. When the slope of the current ramp belongs to the first slope range, it is determined whether the duration is greater than the first time threshold. If it is greater than the first time threshold, it is determined that the type of the current ramp is the first ramp. If it is less than or equal to the first time threshold, it is determined that the type of the current ramp is the second ramp. When the slope of the current ramp belongs to the second slope range, it is determined whether the duration is greater than the second time threshold. If it is greater than the second time threshold, it is determined that the type of the current ramp is the third ramp. If it is less than or equal to the second time threshold, it is determined that the type of the current ramp is the fourth ramp. When the slope of the current ramp belongs to the third slope range, determine whether the duration is greater than the third time threshold. If it is greater than the third time threshold, determine that the type of the current ramp is the fifth ramp. If it is less than or equal to the third time threshold, determine that the type of the current ramp is the sixth ramp.

[0116] The above introduces the braking control method provided by the embodiment of the present application. The following will introduce the braking control device provided by the embodiment of the present application in conjunction with the accompanying drawings.

[0117] like Figure 4 As shown, an embodiment of the present invention further provides a braking control device, the device comprising:

[0118] The first determination module 401 is used to determine the target slope type corresponding to the slope where the vehicle is located and the braking torque required for the whole vehicle when it is detected that the brake pedal is stepped on when the vehicle is in a downhill driving state;

[0119] A second determination module 402 is used to determine a target motor braking ratio corresponding to the target ramp type;

[0120] A first allocation module 403 is used to allocate the vehicle braking demand torque according to the target motor braking ratio to obtain a target motor braking torque and a target hydraulic braking torque; wherein the ratio of the target motor braking torque to the vehicle braking demand torque is the target motor braking ratio;

[0121] The first control module 404 is used to control the motor brake system to output the target motor braking torque and the hydraulic brake system to output the target hydraulic braking torque.

[0122] Optionally, after controlling the motor brake system to output the target motor braking torque and the hydraulic brake system to output the target hydraulic braking torque, the device further includes:

[0123] An acquisition module, used for periodically acquiring a braking energy recovery utilization rate and a deceleration fluctuation value;

[0124] A third determination module is used to determine the motor braking ratio adjustment value according to the current braking energy recovery utilization rate and the current deceleration fluctuation value obtained in the current cycle, and the historical braking energy recovery utilization rate obtained in the previous cycle of the current cycle;

[0125] An adjustment module, used for adjusting the motor braking ratio corresponding to the current cycle according to the motor braking ratio adjustment value to obtain an adjusted motor braking ratio;

[0126] A second allocation module is used to allocate the required braking torque of the whole vehicle according to the adjusted motor braking proportion to obtain the adjusted motor braking torque and the adjusted hydraulic braking torque;

[0127] The second control module is used to control the motor brake system to output the adjusted electric brake torque, and control the hydraulic brake system to output the adjusted hydraulic brake torque.

[0128] Optionally, the acquisition module includes:

[0129] The first acquisition submodule is used to acquire the actual recovered energy value and the recoverable energy value;

[0130] The first determining submodule is used to determine the braking energy recovery utilization rate according to the actual recovered energy value and the recoverable energy value.

[0131] Optionally, the third determining module includes:

[0132] A calculation submodule, used for calculating the difference between the current braking energy recovery utilization rate and the historical braking energy recovery utilization rate to obtain a braking energy recovery utilization rate change value;

[0133] A second determination submodule is used to determine that the motor braking proportion adjustment value is a first preset value when the braking energy recovery utilization rate change value is less than a first threshold value; wherein the first threshold value is less than or equal to zero, and the first preset value is greater than zero;

[0134] A judgment submodule, configured to judge whether the deceleration fluctuation value is greater than a preset fluctuation threshold value when the braking energy recovery utilization rate change value is greater than a second threshold value; wherein the second threshold value is greater than or equal to zero;

[0135] A third determination submodule is used to determine that the motor braking proportion adjustment value is a second preset value when the deceleration fluctuation value is greater than the preset fluctuation threshold, and the second preset value is less than zero;

[0136] A fourth determination submodule, configured to determine that the motor braking proportion adjustment value is zero when the deceleration fluctuation value is less than or equal to the preset fluctuation threshold;

[0137] The fifth determination submodule is used to determine that the motor braking proportion adjustment value is zero when the braking energy recovery utilization rate change value is greater than or equal to the first threshold and the braking energy recovery utilization rate change value is less than or equal to the second threshold.

[0138] Optionally, the second determining module includes:

[0139] The second acquisition submodule is used to acquire the pre-stored correspondence between the ramp type and the motor braking ratio;

[0140] The sixth determination submodule is used to determine the target motor braking ratio according to the corresponding relationship and the target ramp type.

[0141] Optionally, the first determining module includes:

[0142] a seventh determination submodule, configured to determine a slope corresponding to the ramp on which the vehicle is located;

[0143] an eighth determination submodule, configured to determine a target slope range in which the slope is located from a plurality of slope ranges; wherein each slope range corresponds to two types of ramps;

[0144] a ninth determination submodule, configured to determine a target time threshold corresponding to the target slope range, and a duration during which the slope of the vehicle is within the target slope range;

[0145] The tenth determination submodule is used to determine the target ramp type according to the duration, the target time threshold and the preset time threshold.

[0146] Optionally, the tenth determining submodule includes:

[0147] A first determining unit, configured to determine that the target ramp type is a pothole ramp type when the duration is less than or equal to the preset time threshold;

[0148] a second determining unit, configured to determine, when the duration is greater than the preset time threshold and less than the target time threshold, that the target ramp type is a first ramp type corresponding to the target slope range;

[0149] A third determining unit is configured to determine, when the duration is greater than the target time threshold, that the target ramp type is a second ramp type corresponding to the target slope range.

[0150] The braking control device provided by the present application determines a target motor braking ratio that matches the target slope type on which the vehicle is located when the vehicle is in a downhill state and the brake pedal is pressed, and distributes the braking demand torque of the entire vehicle according to the target braking ratio to obtain a target motor braking torque and a target hydraulic braking torque, so that the motor braking system outputs the target motor braking torque and the hydraulic braking system outputs the target hydraulic braking torque. The present application can distribute the ratio of motor braking and hydraulic braking in the braking demand torque of the entire vehicle according to the slope type, and realizes the division of braking energy recovery levels according to the slope type. During the braking process, the vehicle can fully utilize the energy recovery function and ensure sufficient braking force, and can also reduce the wear of braking components in the hydraulic braking system.

[0151] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0152] An embodiment of the present application also provides an electronic device, including: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, the various processes of the above-mentioned braking control method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0153] For example, Figure 5 FIG. 1 shows a schematic diagram of the physical structure of an electronic device. Figure 5As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530 and a communication bus 540, wherein the processor 510, the communication interface 520, and the memory 530 communicate with each other through the communication bus 540. The processor 510 can call the logic instructions in the memory 530, and the processor 510 is used to perform the following steps: when the vehicle is in a downhill driving state, when it is detected that the brake pedal is stepped on, determine the target ramp type corresponding to the ramp where the vehicle is located and the braking torque required for the whole vehicle; determine the target motor braking ratio corresponding to the target ramp type; according to the target motor braking ratio, distribute the braking torque required for the whole vehicle to obtain the target electric motor braking torque and the target hydraulic braking torque; wherein the ratio of the target electric motor braking torque to the braking torque required for the whole vehicle is the target motor braking ratio; control the motor braking system to output the target electric motor braking torque and the hydraulic braking system to output the target hydraulic braking torque. The processor 510 can also execute other schemes in the embodiments of the present application, which will not be further elaborated here.

[0154] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application.

[0155] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, each process of the above-mentioned braking control method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it is not repeated here. The computer-readable storage medium is, for example, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0156] An embodiment of the present application also provides a vehicle, which includes various parts of the above-mentioned braking control device embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0157] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0158] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0159] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0160] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0161] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0162] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0163] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0164] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0165] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0166] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A braking control method, characterized in that: The method comprises: When the vehicle is in a downhill driving state, when it is detected that the brake pedal is stepped on, determining the target slope type corresponding to the slope on which the vehicle is located and the braking torque required for the whole vehicle; Determining a target motor braking ratio corresponding to the target ramp type; According to the target motor braking ratio, the whole vehicle braking demand torque is distributed to obtain a target motor braking torque and a target hydraulic braking torque; wherein the ratio of the target motor braking torque to the whole vehicle braking demand torque is the target motor braking ratio; The motor brake system is controlled to output the target motor braking torque and the hydraulic brake system is controlled to output the target hydraulic braking torque.

2. The braking control method according to claim 1, characterized in that: After controlling the motor brake system to output the target motor braking torque and the hydraulic brake system to output the target hydraulic braking torque, the method further includes: Periodically obtain the braking energy recovery rate and deceleration fluctuation value; Determine the motor braking ratio adjustment value according to the current braking energy recovery utilization rate and the current deceleration fluctuation value obtained in the current cycle, and the historical braking energy recovery utilization rate obtained in the cycle before the current cycle; According to the motor braking ratio adjustment value, the motor braking ratio corresponding to the current cycle is adjusted to obtain the adjusted motor braking ratio; According to the adjusted motor braking proportion, the required braking torque of the whole vehicle is distributed to obtain the adjusted motor braking torque and the adjusted hydraulic braking torque; The motor brake system is controlled to output the adjusted motor braking torque, and the hydraulic brake system is controlled to output the adjusted hydraulic braking torque.

3. The braking control method according to claim 2, characterized in that: Obtain the braking energy recovery rate, including: Obtaining actual recovered energy value and recoverable energy value; The braking energy recovery utilization rate is determined according to the actual recovered energy value and the recoverable energy value.

4. The braking control method according to claim 2, characterized in that: According to the current braking energy recovery utilization rate and the current deceleration fluctuation value obtained in the current cycle, and the historical braking energy recovery utilization rate obtained in the previous cycle of the current cycle, the motor braking proportion adjustment value is determined, including: Calculating the difference between the current braking energy recovery utilization rate and the historical braking energy recovery utilization rate to obtain a braking energy recovery utilization rate change value; When the braking energy recovery utilization rate change value is less than a first threshold, determining the motor braking proportion adjustment value to be a first preset value; wherein the first threshold is less than or equal to zero, and the first preset value is greater than zero; When the braking energy recovery utilization rate change value is greater than a second threshold, determining whether the deceleration fluctuation value is greater than a preset fluctuation threshold; wherein the second threshold is greater than or equal to zero; When the deceleration fluctuation value is greater than the preset fluctuation threshold, determining the motor braking proportion adjustment value to be a second preset value, and the second preset value is less than zero; When the deceleration fluctuation value is less than or equal to the preset fluctuation threshold, determining that the motor braking proportion adjustment value is zero; When the braking energy recovery utilization rate change value is greater than or equal to the first threshold and the braking energy recovery utilization rate change value is less than or equal to the second threshold, it is determined that the motor braking proportion adjustment value is zero.

5. The braking control method according to claim 1, characterized in that: Determining a target motor braking ratio corresponding to the target ramp type includes: Obtaining a pre-stored correspondence between the ramp type and the motor braking ratio; The target motor braking ratio is determined according to the corresponding relationship and the target ramp type.

6. The braking control method according to claim 1, characterized in that: Determining a target ramp type corresponding to the ramp on which the vehicle is located includes: Determining a slope corresponding to the ramp on which the vehicle is located; Determining a target slope range in which the slope is located from a plurality of slope ranges; wherein each slope range corresponds to two ramp types; Determining a target time threshold corresponding to the target slope range, and a duration during which the slope of the vehicle is within the target slope range; The target ramp type is determined according to the duration, the target time threshold and a preset time threshold.

7. The braking control method according to claim 6, characterized in that: Determining the target ramp type according to the duration, the target time threshold, and the preset time threshold includes: When the duration is less than or equal to the preset time threshold, determining that the target ramp type is a pothole ramp type; When the duration is greater than the preset time threshold and less than the target time threshold, determining that the target ramp type is a first ramp type corresponding to the target slope range; When the duration is greater than the target time threshold, the target slope type is determined to be a second slope type corresponding to the target slope range.

8. A brake control device, characterized in that: include: A first determination module is used to determine a target slope type corresponding to the slope on which the vehicle is located and a braking torque requirement of the whole vehicle when it is detected that the brake pedal is stepped on when the vehicle is in a downhill driving state; A second determination module is used to determine a target motor braking ratio corresponding to the target ramp type; A first allocation module is used to allocate the vehicle braking demand torque according to the target motor braking ratio to obtain a target motor braking torque and a target hydraulic braking torque; wherein the ratio of the target motor braking torque to the vehicle braking demand torque is the target motor braking ratio; The first control module is used to control the motor brake system to output the target motor braking torque and the hydraulic brake system to output the target hydraulic braking torque.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the braking control method according to any one of claims 1 to 7 is implemented.

10. A vehicle, characterized in that: The vehicle includes the brake control device according to claim 8.

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