Brake control method, brake control device, vehicle and readable storage medium

Abstract

The invention discloses a brake control method, a brake control device, a vehicle and a readable storage medium. The method comprises the steps that under the condition that a braking intention is detected, a target braking strategy is determined in a torque control strategy and a rotating speed control strategy based on the current rotating speed of a motor of the vehicle, the torque control strategy is used for conducting torque control over the vehicle, and the rotating speed control strategy is used for conducting rotating speed control over the vehicle; and controlling the vehicle to run based on the target braking strategy to reduce the speed of the vehicle until the vehicle is completely static. For example, under the condition that the rotating speed is large, the target braking strategy is determined as the torque control strategy, so that the energy recovery efficiency in the vehicle deceleration process is improved. And under the condition that the rotating speed is small, the target braking strategy is determined as the rotating speed control strategy so as to ensure that the vehicle can be accurately stopped. Thus, the advantages of torque control and rotating speed control can be combined in the braking process, so that the energy recovery efficiency in the braking process can be improved, and it is ensured that the vehicle can be accurately parked at the target position.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more specifically, to a braking control method, a braking control device, a vehicle, and a non-volatile computer-readable storage medium. Background Art

[0002] At present, the related technologies of electric vehicles are booming, and various technologies have emerged for the braking process of electric vehicles, such as torque control methods. The torque control method can realize energy recovery during the deceleration of the vehicle, thereby improving the energy recovery efficiency. However, the torque control method cannot ensure that the vehicle can be accurately parked at the target position. Therefore, how to ensure that the vehicle can be accurately parked at the target position while improving the energy recovery efficiency has become an urgent problem to be solved. Summary of the invention

[0003] Embodiments of the present application provide a braking control method, a braking control device, a vehicle, and a non-volatile computer-readable storage medium.

[0004] The braking control method of the implementation mode of the present application includes, when a braking intention is detected, determining a target braking strategy in a torque control strategy and a speed control strategy based on the current speed of the vehicle's motor, the torque control strategy being used to perform torque control on the vehicle, and the speed control strategy being used to perform speed control on the vehicle; and controlling the vehicle operation based on the target braking strategy to reduce the speed of the vehicle until the vehicle is completely stationary.

[0005] The braking control device of the embodiment of the present application includes a determination module and a control module. The determination module is used to determine the target braking strategy in the torque control strategy and the speed control strategy based on the current speed of the motor of the vehicle when the braking intention is detected. The torque control strategy is used to perform torque control on the vehicle, and the speed control strategy is used to perform speed control on the vehicle. The control module controls the vehicle operation based on the target braking strategy to reduce the speed of the vehicle until the vehicle is completely stationary.

[0006] The vehicle of the embodiment of the present application includes a processor, a memory and a computer program, wherein the computer program is stored in the memory and executed by the processor, and the computer program includes instructions for executing a braking control method. The braking control method includes determining a target braking strategy in a torque control strategy and a speed control strategy based on the current speed of the motor of the vehicle when a braking intention is detected, wherein the torque control strategy is used to perform torque control on the vehicle, and the speed control strategy is used to perform speed control on the vehicle; and controlling the vehicle operation based on the target braking strategy to reduce the speed of the vehicle until the vehicle is completely stationary.

[0007] The non-volatile computer-readable storage medium of the embodiment of the present application includes a computer program, and when the computer program is executed by a processor, the processor executes a braking control method. The braking control method includes determining a target braking strategy in a torque control strategy and a speed control strategy based on the current speed of the motor of the vehicle when a braking intention is detected, the torque control strategy is used to perform torque control on the vehicle, and the speed control strategy is used to perform speed control on the vehicle; and controlling the vehicle operation based on the target braking strategy to reduce the speed of the vehicle until the vehicle is completely stationary.

[0008] The braking control method, braking control device, vehicle and computer-readable storage medium of the embodiments of the present application can determine the target braking strategy based on the current speed of the motor when the braking intention is detected. The target braking strategy can be a torque control strategy or a speed control strategy, and then the vehicle operation is controlled based on the target braking strategy to achieve vehicle braking. For example, when the speed is relatively high, the target braking strategy is determined to be a torque control strategy to perform torque control on the vehicle, thereby improving the energy recovery efficiency during the vehicle deceleration process. When the speed is relatively low, the target braking strategy is determined to be a speed control strategy to perform speed control on the vehicle to ensure that the vehicle can be accurately parked. In this way, the braking process can combine the advantages of torque control and speed control, so that while improving the energy recovery efficiency during the braking process, it can ensure that the vehicle can be accurately parked at the target position.

[0009] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0011] Figure 1 is a schematic flow chart of a braking control method according to certain embodiments of the present application;

[0012] Figure 2 is a schematic flow chart of a braking control method according to certain embodiments of the present application;

[0013] Figure 3 is a schematic flow chart of a braking control method according to certain embodiments of the present application;

[0014] Figure 4 is a schematic flow chart of a braking control method according to certain embodiments of the present application;

[0015] Figure 5is a schematic flow chart of a braking control method according to certain embodiments of the present application;

[0016] Figure 6 is a schematic flow chart of a braking control method according to certain embodiments of the present application;

[0017] Figure 7 is a schematic diagram of a module of a brake control device according to certain embodiments of the present application;

[0018] Figure 8 is a schematic diagram of the structure of a vehicle according to some embodiments of the present application;

[0019] Fig. 9 It is a schematic diagram of the connection status of a non-volatile computer-readable storage medium and a processor in certain embodiments of the present application. DETAILED DESCRIPTION

[0020] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of the present application, and cannot be understood as limiting the embodiments of the present application.

[0021] At present, the relevant technologies of electric vehicles are booming, and a variety of technologies have emerged for the braking process of electric vehicles, such as torque control methods. The torque control method can realize energy recovery during the deceleration of the vehicle, thereby improving the energy recovery efficiency. However, the torque control method cannot ensure that the vehicle can be accurately parked at the target position. Therefore, how to ensure that the vehicle can be accurately parked at the target position while improving the energy recovery efficiency has become an urgent problem to be solved. The speed control method can achieve stable parking of the vehicle, but during the control process of the speed control method, the energy recovery efficiency of the vehicle is low.

[0022] In order to solve the above problems, the embodiment of the present application provides a braking control method, which will be described in detail below:

[0023] See also Figure 1 , the present application embodiment provides a braking control method comprising:

[0024] Step 01: When a braking intention is detected, a target braking strategy is determined in a torque control strategy and a speed control strategy based on a current speed of a motor of the vehicle, wherein the torque control strategy is used to control the torque of the vehicle and the speed control strategy is used to control the speed of the vehicle;

[0025] Specifically, the braking strategy of the vehicle may include a torque control strategy and a speed control strategy. When entering the torque control strategy, the vehicle may be torque controlled according to a torque control method, and when entering the speed control strategy, the vehicle may be speed controlled according to a speed control method.

[0026] The torque control method uses the torque output of the vehicle power system to achieve vehicle deceleration. Its basic principle is to adjust the output torque of the power system to generate a braking torque opposite to the direction of vehicle travel, thereby achieving vehicle deceleration and parking. Under the action of the braking torque, the kinetic energy of the wheels is converted into electrical energy in the motor windings, which can then be captured and sent to the battery to achieve energy recovery and storage.

[0027] The speed control method achieves vehicle deceleration and stopping by controlling the speed of the vehicle's motor. When the vehicle is speed controlled, the target speed of the motor required to stop the vehicle is calculated. The target speed is usually a gradually decreasing speed value until it eventually reaches zero. Then, the vehicle can control the motor operation according to the calculated target speed. For example, according to the preset control algorithm and the actual state of the current motor (such as speed, temperature, etc.), the motor input voltage, current or frequency and other parameters are adjusted to gradually reduce the motor speed to the target speed.

[0028] The first preset throttle threshold is the maximum value of the throttle depth when the driver has a braking intention, for example, 3%, so the braking intention at least includes the throttle depth being less than the first preset throttle threshold. When the driver releases the throttle, the throttle depth is less than the first preset throttle threshold, and the vehicle can detect that the driver has a braking intention.

[0029] When the braking intention is detected, the target braking strategy can be determined according to the speed of the motor. For example, when the vehicle speed is high and the speed is high, the target braking strategy is confirmed to be a torque control strategy to improve the energy recovery efficiency and make the energy management strategy more refined. When the speed is low, the target braking strategy is confirmed to be a speed control strategy, so that the speed control interval is small to improve the control accuracy of the motor speed. At the same time, when the throttle depth is less than the first preset throttle threshold, the vehicle speed and the motor speed are reduced synchronously. In this way, torque control is performed first at higher vehicle speeds and speeds to improve energy recovery efficiency. When the vehicle speed decreases and the speed is low, speed control is performed to quickly adjust the vehicle state until it stops and achieve stable parking of the vehicle.

[0030] Step 02: Control the vehicle operation based on the target braking strategy to reduce the speed of the vehicle until the vehicle comes to a complete stop.

[0031] Specifically, after determining the target braking strategy, the vehicle operation can be controlled based on the target braking strategy to reduce the speed of the vehicle. For example, when the target braking strategy is a torque control strategy, the vehicle can be torque controlled to improve the energy recovery efficiency while reducing the speed of the vehicle. When the target braking strategy is a speed control strategy, the vehicle can be speed controlled to achieve precise control of the vehicle from low speed to stationary by adjusting the motor speed. When the vehicle stops completely, it can be determined that the braking strategy has been executed.

[0032] In this way, when the braking intention is detected, the target braking strategy to be executed can be determined in real time according to the current speed of the motor, so that the whole vehicle can be stopped by combining torque control and speed control during the braking process. During the vehicle braking process, torque control can be used to improve the efficiency of energy recovery, and speed control can be used to ensure that the vehicle can finally stop accurately at the target position. At the same time, compared with the traditional technical solution that relies on the brake pedal for braking, this solution does not require the driver to step on the brake pedal during the braking process. The braking process begins when the accelerator is released, reducing unnecessary operations by the driver.

[0033] When the braking intention is detected, the braking control method of the embodiment of the present application can determine the target braking strategy based on the current speed of the motor. The target braking strategy can be a torque control strategy or a speed control strategy, and then the vehicle operation is controlled based on the target braking strategy to achieve vehicle braking. For example, when the speed is relatively high, the target braking strategy is determined to be a torque control strategy to perform torque control on the vehicle, thereby improving the energy recovery efficiency during vehicle deceleration. When the speed is relatively low, the target braking strategy is determined to be a speed control strategy to perform speed control on the vehicle to ensure that the vehicle can be accurately parked. In this way, the braking process can combine the advantages of torque control and speed control, so that while improving the energy recovery efficiency during braking, it can ensure that the vehicle can be accurately parked at the target position.

[0034] See also Figure 2 In some embodiments, step 01: determining a target braking strategy in a torque control strategy and a speed control strategy based on a current speed of a motor of a vehicle, comprising:

[0035] Step 011: If the current running information of the vehicle does not meet the preset switching condition, determine that the target braking strategy is a torque control strategy, the torque control strategy performs torque control on the vehicle based on the current running information of the vehicle and a corresponding preset torque curve, and the preset switching condition at least includes that the motor speed of the vehicle is less than a preset speed threshold;

[0036] Step 012: If the current operating information of the vehicle meets the preset switching condition, the target braking strategy is determined to be a speed control strategy, and the speed control strategy controls the speed of the vehicle based on the current operating information of the vehicle.

[0037] Specifically, the preset speed threshold is the speed of the motor when the target braking strategy switches between the two strategies, the vehicle shakes less, and various performances of the vehicle are better, such as the vibration amplitude of the vehicle is smaller, to ensure that the vehicle can smoothly switch the braking strategy.

[0038] When braking intention is detected, the vehicle's operating information can be collected, such as the accelerator pedal, slope information, real-time vehicle speed, following distance, current gear, Electronic Park Brake (EPB) system status, motor speed, and other information input through sensors or other modules of the vehicle.

[0039] The operation information can reflect the current working condition of the vehicle. Under different working conditions, the corresponding torque when the vehicle can achieve maximum energy recovery or maximum recovery may be different. Therefore, a preset torque curve can be set according to the torque corresponding to the vehicle's maximum energy recovery or maximum recovery under different working conditions, so that the preset torque curve can be used to reflect the mapping relationship between the operation information and the corresponding torque. For example, the preset torque curve can reflect the mapping relationship between the vehicle speed, the following distance and the corresponding torque. There can be multiple preset torque curves, and different preset torque curves correspond to different working conditions. For example, the operation information includes driving information, and the driving information includes the following distance. The preset torque curves corresponding to different following distances are different, so as to ensure that the vehicle will not collide with the vehicle in front on the one hand, and on the other hand, ensure that the vehicle can be decelerated and the energy can be recovered to the maximum during braking.

[0040] When the current operation information of the vehicle does not meet the preset switching conditions, for example, when the accelerator is just released and the motor speed is greater than the preset speed threshold, the target braking strategy can be determined as the torque control strategy. The torque control strategy determines the target torque according to the current operation information of the vehicle and the preset torque curve, and then performs torque control on the vehicle according to the target torque. It can be understood that the target torque matches the current operation information, so that after the vehicle is torque controlled according to the target torque, it can ensure that the vehicle can be decelerated on the one hand, and maximize energy recovery or maximize recovery on the other hand.

[0041] After the driver releases the accelerator, the motor speed will gradually decrease, and the vehicle speed will also gradually decrease. When the motor speed is less than or equal to the preset speed threshold, it can be considered that the current operation information of the vehicle meets the preset switching conditions. During the process of switching the target braking strategy from the torque control strategy to the speed control strategy, and after the switching is completed, the vehicle can operate stably, so the braking strategy is determined to be the speed control strategy. At this time, the vehicle speed is controlled based on the current operation information of the vehicle. For example, the motor speed can be controlled according to the proportional-integral (PI) control algorithm and the current operation information, so as to use the speed control strategy to ensure that the vehicle can finally stop accurately at the target position.

[0042] In this way, after releasing the accelerator, the torque control strategy can be executed first, and then the vehicle's braking strategy can be switched from the torque control strategy to the speed control strategy according to the preset switching conditions. At the same time, the present application can combine the advantages of the two control modes to ensure that the vehicle can decelerate smoothly during braking until the vehicle stops, and at the same time, energy can be maximized during braking. Recovery.

[0043] See also Figure 3 In some embodiments, the current operation information includes slope information and driving information, the preset torque curve includes a first torque curve, a second torque curve and a third torque curve, the first torque curve corresponds to a flat road section and driving information, the second torque curve corresponds to a slope road section and driving information, and the third torque curve corresponds to a slope road section, driving information and a slope value in the slope information; when the target braking strategy is a torque control strategy, step 02: controlling the vehicle operation based on the target braking strategy includes:

[0044] Step 021: when the slope information shows that the current road section is a flat road section, determining a first target torque according to the driving information and the first torque curve, and controlling the vehicle operation based on the first target torque;

[0045] Step 022: when the slope information shows that the current road section is a slope road section and the current vehicle speed is greater than a preset vehicle speed threshold, determining a second target torque according to the driving information and the second torque curve, and controlling the vehicle operation based on the second target torque;

[0046] Step 023: When the slope information shows that the current road section is a slope section and the current vehicle speed is less than the preset vehicle speed threshold, the second target torque is determined according to the driving information and the second torque curve, and the third target torque is determined according to the driving information, the slope value and the third torque curve, and the vehicle operation is controlled based on the second target torque and the third target torque.

[0047] Specifically, the current operation information may include slope information and driving information. The slope information may include the slope value and slope direction of the current road section where the vehicle is traveling. The driving information may include the current vehicle speed and the forward distance. The preset torque curves corresponding to different slopes may be different, so the corresponding preset torque curves may be set according to the corresponding conditions of different slopes. The preset torque curve includes a first torque curve, a second torque curve and a third torque curve. The first torque curve corresponds to a flat road section and driving information. At this time, the first torque curve reflects the mapping relationship between the driving information and the corresponding torque when the vehicle is traveling on a flat road section, for example, it can reflect the mapping relationship between the current vehicle speed and the forward distance and the corresponding torque when the vehicle is traveling on a flat road section. The second torque curve corresponds to the slope road section and driving information. At this time, the second torque curve reflects the mapping relationship between the driving information and the corresponding torque when the vehicle is traveling on a slope road section, for example, it can reflect the mapping relationship between the current vehicle speed and the forward distance and the corresponding torque when the vehicle is traveling on a slope road section. The third torque curve corresponds to the slope section, driving information and slope value. At this time, the third torque curve reflects the mapping relationship between driving information, slope value and corresponding torque when the vehicle is traveling on the slope section. For example, it can reflect the mapping relationship between the current vehicle speed, forward distance, slope value and corresponding torque when the vehicle is traveling on the slope section.

[0048] After obtaining the slope information, the slope information can be used to determine whether the current road section is a ramp section. For example, a preset slope threshold can be set, such as 6°. If the slope value is greater than the preset slope threshold, the current road section is confirmed to be a ramp section, otherwise it is a flat road section. If the slope value has positive and negative values, the absolute value of the slope value is compared with the preset slope threshold to determine whether the current road section is a ramp section.

[0049] When the slope information shows that the current road section is a flat section, the vehicle has no risk of rolling down the slope. At this time, the first target torque can be determined based on the driving information and the first torque curve corresponding to the flat section. At this time, the first target torque is the feedback torque, so that the first target torque matches the current driving information. Then the vehicle operation can be controlled according to the first target torque to reduce the speed of the vehicle on the one hand and recover as much energy as possible on the other hand, thereby improving the energy recovery efficiency. The first target torque can be a positive number or a negative number, and different signs correspond to different directions. The sign of the first target torque needs to be calculated according to the corresponding preset torque curve.

[0050] On a slope section, when the vehicle speed is high, there is no risk of rolling down the slope, so a preset vehicle speed threshold may also be set. The preset vehicle speed threshold is the minimum speed of the vehicle when there is no risk of the vehicle rolling down the slope section.

[0051] When the slope information shows that the current road section is a slope section and the vehicle speed is greater than the preset speed threshold, the vehicle has no risk of rolling down the slope. At this time, the second target torque can be determined according to the driving information and the second torque curve corresponding to the slope section. At this time, the second target torque is the feedback torque, so that the second target torque matches the current driving information, wherein the direction of the second target torque is opposite to the forward direction of the vehicle, so that the second target torque can be used to reduce the speed of the vehicle. Then, the vehicle operation can be controlled according to the second target torque to reduce the speed of the vehicle on the one hand and recover as much energy as possible on the other hand, thereby improving the energy recovery efficiency.

[0052] When the slope information shows that the current road section is a slope section and the vehicle speed is less than the preset speed threshold, the vehicle is at risk of sliding down the slope. Therefore, in addition to the second target torque, the third target torque needs to be added to further prevent the vehicle from sliding down the slope. At this time, the second target torque can be determined according to the driving information and the second torque curve, and the third target torque can be determined according to the driving information, the slope value and the third torque curve, and then the vehicle operation is controlled based on the second target torque and the third target torque. The third target torque is a compensation torque, which is a feedforward control of the vehicle's stable slope during braking. For example, the third target torque can be dynamically adjusted using the current vehicle speed, the following distance and the slope inclination angle, and the third target torque that can prevent the vehicle from sliding down the slope is output before parking, so as to avoid the subsequent speed feedback adjustment amplitude being large and then stopping after sliding down the slope. Among them, the third target torque can be a positive number or a negative number, and different signs correspond to different directions. For example, when the third target torque is preset to be a positive number, the direction corresponding to the third target torque is from the rear wheels of the vehicle to the front wheels, and when the third target torque is preset to be a negative number, the direction corresponding to the third target torque is from the front wheels of the vehicle to the rear wheels.

[0053] In the case of an uphill slope, the direction of the vehicle's slipping is from the front wheels to the rear wheels. In this case, the third target torque is a positive number, so that when the second target torque is small, the third target torque can also prevent the vehicle from slipping due to gravity. In the case of a downhill slope, the direction of the vehicle's slipping is from the rear wheels to the front wheels. In this case, the third target torque is a negative number, so that the second target torque and the third target torque can work together to prevent the vehicle from slipping. Of course, the sign of the third target torque is not necessarily only related to the direction of the vehicle's slipping, and it needs to be determined according to the corresponding preset torque curve.

[0054] In this way, when torque control is performed, the corresponding target torque can be determined according to the road condition of the vehicle. In a flat road section, the first target torque can be dynamically adjusted by driving information, such as the following distance and the vehicle speed. In a slope section, when the vehicle speed is greater than the preset vehicle speed threshold, the second target torque can be dynamically adjusted by driving information, such as the following distance and the vehicle speed. In the case where the vehicle is in a slope section and the vehicle speed is less than the preset vehicle speed threshold, in addition to the second target torque, a third target torque adaptively adjusted by driving information and slope information is added, so that the vehicle can decelerate smoothly until entering the speed control strategy. At this time, the braking process is more intelligent, and the vehicle energy can be finely managed under the premise of stable parking, that is, the corresponding target torque is determined according to different road conditions, so that energy recovery can be maximized under different road conditions, so that the adaptability of the present application is strong and can be used for a variety of road conditions. Therefore, compared with the technical solution that only relies on the speed control mode or the torque control strategy for braking, the braking process of the present application not only solves the problem that a single torque control strategy cannot ensure stable parking of the vehicle, but also solves the problem that a single speed control strategy cannot be dynamically adjusted under different road conditions.

[0055] In addition, the vehicle of the present application may also include a single-pedal mode, which simplifies the acceleration and deceleration operations into one pedal. In this mode, when the driver steps on the accelerator, the vehicle will accelerate; when the accelerator is released, the vehicle will automatically decelerate; after the accelerator is completely released, the vehicle will automatically stop. When the driver steps on the brake pedal, energy recovery will be suspended, resulting in a decrease in energy recovery efficiency. However, the present application can achieve braking without stepping on the brake pedal. Therefore, when the vehicle of the present application is in the single-pedal mode, the negative impact of stepping on the brake pedal on energy recovery can also be reduced.

[0056] In some embodiments, the preset switching condition may also include the vehicle's current gear being a preset gear, for example, the preset gear is D gear or R gear. The preset switching condition may also include the EPB state being an unlocked state, that is, the EPB is not locked, to ensure that after accurately entering the speed control strategy, the vehicle is in a braking parking condition.

[0057] At the same time, the preset speed threshold corresponding to the slope section and the preset speed threshold corresponding to the flat section may be different. For example, the preset speed threshold corresponding to the flat section is smaller than the preset speed threshold corresponding to the slope section, so as to ensure that it is possible to more accurately determine whether it is necessary to enter the speed control strategy.

[0058] Alternatively, the preset switching condition may further include that the throttle depth is less than a first preset throttle threshold value, so as to ensure that the vehicle is in a braking parking condition after entering the speed control strategy.

[0059] In one embodiment, the preset gear is D gear, the preset speed threshold corresponding to the slope section is 100rpm, and the first preset throttle threshold is 3%. When the vehicle is on a flat road section, entering the speed control strategy requires the following conditions to be met at the same time: the current gear is D gear, the EPB is not locked, the slope value is greater than |6|°, the real-time motor speed is less than 100rpm, and the throttle depth is less than 3%.

[0060] In another embodiment: the preset gear is D gear, the preset speed threshold corresponding to the flat road section is 30rpm, and the first preset throttle threshold is 3%. Then, when the vehicle is on a flat road section, entering the speed control strategy requires the following conditions to be met at the same time: the current gear is D gear, the EPB is not locked, the slope is less than or equal to |6|°, the real-time motor speed is less than 30rpm, and the throttle depth is less than 3%.

[0061] See also Figure 4 In some embodiments, the current operation information includes the current speed of the motor. When the target braking strategy is a speed control strategy, step 02: controlling the vehicle operation based on the target braking strategy includes:

[0062] Step 024: Determine a target speed of the vehicle based on the current speed and the preset speed;

[0063] Step 025: Control the motor operation of the vehicle according to the target speed to reduce the speed of the vehicle.

[0064] Specifically, when the vehicle's current operating information meets the preset switching conditions, the target braking strategy can be determined as the speed control strategy. At this time, the motor begins to intervene and the PI control algorithm is used to adjust the motor speed. The vehicle's target speed is determined based on the current speed and the preset speed, and the motor operation is controlled according to the target speed to reduce the vehicle's speed until the vehicle stops.

[0065] The PI control algorithm is a widely used algorithm for motor speed control. It combines proportional control and integral control to achieve precise control by adjusting the motor speed. Proportional control is adjusted according to the current deviation, while integral control is adjusted according to the historical deviation, thereby eliminating the static error of the system.

[0066] First, the current speed can be compared with the preset speed to obtain the speed difference (error), where the preset speed can be gradually reduced to 0 during the braking process. Then, according to the principles of proportional control and integral control, the control amount is calculated, which is determined by the size of the error and the historical accumulation of the error. Then, the input voltage of the motor can be controlled by adjusting the duty cycle of the PWM wave, thereby adjusting the speed of the motor. When it is necessary to stop, the motor can be controlled to gradually decelerate until it stops by gradually reducing the duty cycle of the PWM wave.

[0067] In this way, after entering the speed control strategy, the speed of the motor can be effectively adjusted according to the current speed and the preset speed to ensure that the vehicle can decelerate smoothly to a complete stop.

[0068] See also Figure 5 In some embodiments, the braking control method further comprises:

[0069] Step 03: When the vehicle is stationary and on a flat road, the electronic parking brake system of the vehicle is maintained in an unlocked state;

[0070] Step 04: When the vehicle is stationary and on a slope, adjust the state of the electronic parking brake system to a locked state and unload the torque of the motor;

[0071] Step 05: When the vehicle is stationary and the throttle depth is greater than a second preset throttle threshold, the state of the vehicle's electronic parking brake system is adjusted to an unlocked state, and the vehicle is started.

[0072] Specifically, when the vehicle speed gradually drops to 0 and is in a stationary state, the parking method can be determined according to the slope of the road section on which the vehicle is traveling to complete the parking action.

[0073] During vehicle operation, the electronic parking brake system is in an unlocked state. When the vehicle is on a flat road, there is no risk of the vehicle rolling away, and the vehicle can be parked accurately even if the electronic parking brake system is not activated. Therefore, the electronic parking brake system can be kept in an unlocked state at this time to reduce unnecessary work of the electronic parking brake system, thereby reducing unnecessary losses of the electronic parking brake system and reducing costs.

[0074] When the vehicle is on a slope, there is a risk of the vehicle rolling down the slope. Therefore, the electronic parking brake system needs to be locked, that is, the electronic parking brake system needs to be locked to ensure that the vehicle does not roll down the slope and improve the safety of the vehicle. The torque of the motor can also be unloaded at this time to prevent the motor from being relied on for a long time to maintain stability on the slope, resulting in the motor workload lasting for a long time, which may lead to overheating and damage to the motor.

[0075] The second preset throttle threshold can be set according to the throttle depth when the driver starts the vehicle, for example, the second preset throttle threshold is 35%. When the vehicle is stationary and the throttle depth is greater than the second preset throttle threshold, it can be considered that the driver needs to start the car. At this time, the state of the vehicle's electronic parking brake system can be adjusted to an unlocked state, and the vehicle can be started.

[0076] In this way, after the vehicle stops, the corresponding parking method can be determined according to the slope of the road section where the vehicle is traveling, so as to ensure that the vehicle can be parked accurately on the one hand, and reduce unnecessary losses of the electronic parking brake system on the other hand, thereby increasing the service life of the electronic parking brake system. When the driver steps on the accelerator and the accelerator depth is greater than the second preset accelerator threshold, the electronic parking brake system can be automatically unlocked and the vehicle can be started, so that the vehicle can be moved by controlling the accelerator alone, thereby improving driving smoothness. Therefore, in the single-pedal mode, the driver can park and start the vehicle by controlling the accelerator, reducing the number of times the driver steps on the brake, making the driver's operation easier and smoother, while also reducing brake consumption and increasing the service life of the brake.

[0077] See also Figure 6 In some embodiments, the braking control method further comprises:

[0078] Step 06: When the vehicle is stationary, maintain the current gear position of the vehicle.

[0079] Specifically, after the vehicle is accurately parked on a flat road section or a sloped road section, the current gear position of the vehicle can be maintained unchanged, so that after the vehicle is started, the vehicle can be driven without changing the gear position.

[0080] Therefore, when the driver needs to start the vehicle and steps on the accelerator, the vehicle's current gear is the forward gear and the vehicle can move forward directly. In this way, the driver does not need to switch gears from parking to restarting the vehicle, thereby improving the smoothness of driving operations.

[0081] In addition, under the existing technical solutions, the unlocking and locking of the EPB is usually accompanied by gear switching, while the present application locks the EPB on a sloped road section without shifting gears. After the driver automatically unlocks the EPB by stepping on the accelerator (the accelerator depth reaches a second preset accelerator threshold), since the current gear is the forward gear, the vehicle can move forward directly without manually switching gears, thereby improving the smoothness of driving operations.

[0082] See also Figure 7 In order to better implement the braking control method of the embodiment of the present application, the embodiment of the present application also provides a braking control device 10. The braking control device 10 may include a determination module 11 and a control module 12. The determination module 11 is used to determine the target braking strategy in the torque control strategy and the speed control strategy based on the current speed of the motor of the vehicle when the braking intention is detected. The torque control strategy is used to perform torque control on the vehicle, and the speed control strategy is used to perform speed control on the vehicle. The control module 12 is used to control the operation of the vehicle based on the target braking strategy to reduce the speed of the vehicle until the vehicle is completely stationary.

[0083] The determination module 11 is specifically used to determine that the target braking strategy is a torque control strategy if the current operating information of the vehicle does not meet the preset switching conditions. The torque control strategy performs torque control on the vehicle based on the current operating information of the vehicle and a preset torque curve. The preset switching conditions at least include that the motor speed of the vehicle is less than a preset speed threshold; if the current operating information of the vehicle meets the preset switching conditions, determine that the target braking strategy is a speed control strategy. The speed control strategy performs speed control on the vehicle based on the current operating information of the vehicle.

[0084] The control module 12 is specifically used to determine the first target torque according to the driving information and the first torque curve when the slope information shows that the current road section is a flat section, and control the vehicle operation based on the first target torque; when the slope information shows that the current road section is a ramp section and the current vehicle speed is greater than a preset vehicle speed threshold, determine the second target torque according to the driving information and the second torque curve, and control the vehicle operation based on the second target torque; when the slope information shows that the current road section is a ramp section and the current vehicle speed is less than the preset vehicle speed threshold, determine the second target torque according to the driving information and the second torque curve, determine the third target torque according to the driving information, the slope value and the third torque curve, and control the vehicle operation based on the second target torque and the third target torque.

[0085] The control module 12 is specifically used to determine a target speed of the vehicle based on a current speed and a preset speed; and control the motor operation of the vehicle according to the target speed to reduce the speed of the vehicle.

[0086] The brake control device 10 further includes a parking module 13 and a starting module 14. The parking module 13 is used to maintain the state of the electronic parking brake system of the vehicle in an unlocked state when the vehicle is stationary and located on a flat road section; when the vehicle is stationary and located on a slope section, the state of the electronic parking brake system is adjusted to a locked state and the torque of the motor is unloaded. The starting module 14 is used to adjust the state of the electronic parking brake system of the vehicle to an unlocked state and start the vehicle when the vehicle is stationary and the throttle depth is greater than a second preset throttle threshold.

[0087] The brake control device 10 further includes a maintaining module 15. The maintaining module 15 is used to maintain the current gear position of the vehicle unchanged when the vehicle is stationary.

[0088] The above describes the brake control device 10 from the perspective of functional modules in conjunction with the accompanying drawings. The functional modules can be implemented in hardware form, can be implemented in software form, or can be implemented in combination with hardware and software modules. Specifically, the steps of the method embodiment in the embodiment of the present application can be completed by the hardware integrated logic circuit in the processor and / or the instructions in software form. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware coding processor, or can be executed by a combination of hardware and software modules in the coding processor. Optionally, the software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps in the above method embodiment in combination with its hardware.

[0089] See also Figure 8 The vehicle 100 of the embodiment of the present application includes a processor 20, a memory 30 and a computer program, wherein the computer program is stored in the memory 30 and executed by the processor 20, and the computer program includes instructions for executing the braking control method of any of the above-mentioned embodiments.

[0090] See also Fig. 9 The embodiment of the present application also provides a computer-readable storage medium 300 on which a computer program 310 is stored. When the computer program 310 is executed by a processor 320, the steps of the braking control method of any of the above-mentioned embodiments are implemented. For the sake of brevity, they are not repeated here.

[0091] In the description of this specification, the descriptions with reference to the terms "certain embodiments", "in an example", "exemplarily", etc., mean that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0092] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0093] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A braking control method, characterized in that: The method comprises: In the case where a braking intention is detected, determining a target braking strategy in a torque control strategy and a speed control strategy based on a current speed of a motor of the vehicle, wherein the torque control strategy is used to perform torque control on the vehicle and the speed control strategy is used to perform speed control on the vehicle; The vehicle operation is controlled based on the target braking strategy to reduce the speed of the vehicle until the vehicle comes to a complete stop.

2. The braking control method according to claim 1, characterized in that: The method of determining a target braking strategy in a torque control strategy and a speed control strategy based on a current speed of a motor of the vehicle includes: If the current operation information of the vehicle does not meet the preset switching condition, determining that the target braking strategy is a torque control strategy, the torque control strategy performs torque control on the vehicle based on the current operation information of the vehicle and a preset torque curve, and the preset switching condition at least includes that the motor speed of the vehicle is less than a preset speed threshold; If the current running information of the vehicle meets the preset switching condition, the target braking strategy is determined to be a speed control strategy, and the speed control strategy controls the speed of the vehicle based on the current running information of the vehicle.

3. The braking control method according to claim 2, characterized in that: The current operation information includes slope information and driving information, the preset torque curve includes a first torque curve, a second torque curve and a third torque curve, the first torque curve corresponds to a flat road section and the driving information, the second torque curve corresponds to a slope road section and the driving information, and the third torque curve corresponds to the slope road section, the driving information and a slope value in the slope information; In the case where the target braking strategy is a torque control strategy, controlling the vehicle operation based on the braking strategy includes: When the slope information shows that the current road section is a flat road section, determining a first target torque according to the driving information and the first torque curve, and controlling the vehicle operation based on the first target torque; When the slope information shows that the current road section is a slope road section and the current vehicle speed is greater than a preset vehicle speed threshold, determining a second target torque according to the driving information and the second torque curve, and controlling the vehicle operation based on the second target torque; When the slope information shows that the current road section is a slope section and the current vehicle speed is less than a preset vehicle speed threshold, the second target torque is determined according to the driving information and the second torque curve, and the third target torque is determined according to the driving information, the slope value and the third torque curve, and the vehicle operation is controlled based on the second target torque and the third target torque.

4. The braking control method according to claim 2, characterized in that: The current operation information includes the current speed of the motor. When the target braking strategy is a speed control strategy, controlling the vehicle operation based on the braking strategy includes: determining a target speed of the vehicle based on the current speed and a preset speed; The operation of the motor of the vehicle is controlled according to the target speed to reduce the speed of the vehicle.

5. The braking control method according to claim 1, characterized in that: The braking intention at least includes that the throttle depth is less than a first preset throttle threshold.

6. The braking control method according to claim 1, characterized in that: The method further comprises: When the vehicle is stationary and located on a flat road section, maintaining the state of the electronic parking brake system of the vehicle in an unlocked state; When the vehicle is stationary and located on a slope, adjusting the state of the electronic parking brake system to a locked state and unloading the torque of the motor; When the vehicle is stationary and the throttle depth is greater than a second preset throttle threshold, the state of the electronic parking brake system of the vehicle is adjusted to an unlocked state, and the vehicle is started.

7. The braking control method according to claim 6, characterized in that: The method further comprises: When the vehicle is stationary, the current gear position of the vehicle is maintained unchanged.

8. The braking control method according to claim 2, characterized in that: The preset switching condition also includes that the current gear of the vehicle is a preset gear, the state of the electronic parking brake system of the vehicle is unlocked, and the preset speed threshold corresponding to the flat road section is different from the preset speed threshold corresponding to the slope road section.

9. A brake control device, characterized in that: include: a determination module, configured to determine a target braking strategy from a torque control strategy and a speed control strategy based on a current speed of a motor of the vehicle when a braking intention is detected, wherein the torque control strategy is used to perform torque control on the vehicle and the speed control strategy is used to perform speed control on the vehicle; The control module controls the vehicle operation based on the target braking strategy to reduce the speed of the vehicle until the vehicle is completely stationary.

10. A vehicle, characterized in that: include: Processor, memory; and A computer program, wherein the computer program is stored in the memory and executed by the processor, and the computer program includes instructions for executing the brake control method according to any one of claims 1 to 8.

11. A non-volatile computer-readable storage medium containing a computer program, characterized in that: When the computer program is executed by a processor, the processor executes the braking control method according to any one of claims 1 to 8.

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