Control method for electric vehicle non-sensing braking, vehicle controller and electric vehicle

Abstract

The present application provides a control method for the senseless braking of an electric vehicle, a vehicle controller and an electric vehicle, which are applied in the field of vehicle technology to reduce the jerking of the electric vehicle during braking. Among them, at a first moment, the braking device of the electric vehicle is controlled to brake the electric vehicle; at a second moment after the first moment, the drive motor is controlled to output a compensating torque in the same direction as the rotation speed of the wheel and the suspension is controlled to increase the damping. Based on this, the deceleration of the electric vehicle during braking is reduced, thereby reducing the jerking phenomenon caused by the rapid rate of change of the vehicle speed during braking of the electric vehicle, and when the drive motor outputs the compensating torque to cause the electric vehicle to transfer load, the increased damping of the suspension can ensure the vibration suppression effect of the body of the electric vehicle, thereby further reducing the jerking phenomenon of the electric vehicle during braking and improving the user's driving experience.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a control method for a sensorless braking of an electric vehicle, a vehicle controller and an electric vehicle. Background Art

[0002] With the development of electric vehicles, the driving experience of electric vehicles has received more and more attention, among which the braking performance of electric vehicles is a key factor affecting the driving experience of electric vehicles. During the braking process of electric vehicles, especially at the end of braking, there is an obvious setback phenomenon.

[0003] In order to reduce the jerking phenomenon during the braking process of the whole vehicle, the braking device is controlled to release a certain wheel-end braking force or the drive device is controlled to output a compensating torque to reduce the deceleration of the whole vehicle. However, when the deceleration changes, the electric vehicle will undergo load transfer, causing the electric vehicle to still experience jerking during the braking process, affecting the user's driving experience. Summary of the invention

[0004] The present application provides a control method for the sensorless braking of an electric vehicle, a vehicle controller and an electric vehicle, which are used to control the drive motor and suspension of the electric vehicle during the braking process of the electric vehicle to reduce the jerking of the electric vehicle during the braking process and improve the driving experience of the user.

[0005] In order to achieve the above objectives, the embodiments of the present application provide the following technical solutions.

[0006] In a first aspect, the present application provides a control method for the sensorless braking of an electric vehicle, which is used to control a drive motor and a suspension of the electric vehicle during the braking process of the electric vehicle to reduce the jerking of the electric vehicle during the braking process. The control method comprises: at a first moment, controlling the braking device of the electric vehicle to brake the electric vehicle; at a second moment after the first moment, during the process of the braking device braking the electric vehicle, controlling the drive motor to output a compensation torque and controlling the suspension to increase damping; wherein the direction of the compensation torque is the same as the direction of the rotation speed of the wheels of the electric vehicle.

[0007] In the embodiment of the present application, during the braking process of the electric vehicle, the vehicle controller reduces the deceleration of the electric vehicle during braking by controlling the drive motor to output a compensating torque in the same direction as the wheel rotation speed and controlling the suspension to increase damping, thereby reducing the jerking phenomenon of the electric vehicle caused by the rapid rate of change of vehicle speed during braking. When the drive motor outputs the compensating torque to cause the electric vehicle to transfer load, the increased damping of the suspension can ensure the effect of suppressing the vibration of the electric vehicle body, thereby further reducing the jerking phenomenon of the electric vehicle during braking and improving the user's driving experience.

[0008] In one embodiment, at the second moment, the deceleration of the electric vehicle during braking is less than a preset deceleration and the vehicle speed is less than a preset vehicle speed.

[0009] During the braking process of an electric vehicle, if the deceleration of the electric vehicle during braking is less than the preset deceleration and the vehicle speed is less than the preset vehicle speed, it can be determined that the braking mode of the electric vehicle is a non-emergency braking mode and is in the final stage of braking, so that the drive motor can be controlled to output a compensating torque and the suspension can be controlled to increase damping.

[0010] In one implementation, at the second moment, the speed reduction rate of the driving motor is less than a preset speed reduction rate and the speed of the driving motor is less than a preset speed.

[0011] During the braking process of an electric vehicle, if the speed reduction rate of the driving motor of the electric vehicle during braking is less than the preset reduction rate and the speed of the driving motor is less than the preset speed, it can be determined that the braking mode of the electric vehicle is a non-emergency braking mode and is in the final stage of braking, so that the driving motor can be controlled to output a compensating torque and the suspension can be controlled to increase damping.

[0012] In one embodiment, the control method specifically includes: at a third moment after the second moment, in response to a decrease in the rate of decrease in the rotation speed of the drive motor, controlling the drive motor to reduce the compensation torque and controlling the suspension to increase damping.

[0013] In the above manner, the speed reduction rate of the drive motor changes due to changes in the operating conditions and external environment of the electric vehicle. When the speed reduction rate of the drive motor decreases, the compensating torque output by the drive motor is controlled to decrease and the damping of the suspension is controlled to increase, thereby ensuring that the control of the drive motor and the suspension can adapt to changes in driving conditions, thereby reducing the fluctuation of deceleration during the braking process of the electric vehicle and improving the braking performance of the electric vehicle.

[0014] In one embodiment, the above control method specifically includes: at the third moment, controlling the compensation torque reduction value of the drive motor to increase as the speed reduction rate of the drive motor decreases, and controlling the damping increase value of the suspension to increase as the speed reduction rate of the drive motor decreases.

[0015] In this embodiment, the actual rate of decrease of the speed of the driving motor of the electric vehicle is used as a feedback signal to adjust the output torque of the driving motor and the damping increase value of the suspension in real time, thereby realizing closed-loop control of the deceleration of the electric vehicle, reducing the fluctuation of the deceleration during the braking process of the electric vehicle, thereby reducing the jerking phenomenon of the electric vehicle during the braking process and improving the driving experience of the user.

[0016] In one embodiment, the control method specifically includes: at a third moment after the second moment, in response to an increase in the rate of decrease of the rotation speed of the drive motor, controlling the drive motor to increase the compensation torque and controlling the suspension to increase the damping.

[0017] In this embodiment, the speed reduction rate of the drive motor changes due to changes in the operating conditions and external environment of the electric vehicle. When the speed reduction rate of the drive motor increases, the compensating torque output by the drive motor is controlled to increase and the damping of the suspension is controlled to increase, thereby ensuring that the control of the drive motor and the suspension can adapt to changes in driving conditions, thereby reducing the fluctuation of deceleration during the braking process of the electric vehicle and improving the braking performance of the electric vehicle.

[0018] In one embodiment, the above control method specifically includes: at the third moment, controlling the increase value of the compensation torque of the drive motor to increase as the rate of reduction of the speed of the drive motor increases, and controlling the increase value of the damping of the suspension to increase as the rate of reduction of the speed of the drive motor increases.

[0019] In this embodiment, the actual rate of decrease of the speed of the driving motor of the electric vehicle is used as a feedback signal to adjust the output torque of the driving motor and the damping increase value of the suspension in real time, thereby realizing closed-loop control of the deceleration of the electric vehicle, reducing the fluctuation of the deceleration during the braking process of the electric vehicle, thereby reducing the jerking phenomenon of the electric vehicle during the braking process and improving the driving experience of the user.

[0020] In one embodiment, the above control method specifically includes: controlling the compensation torque output by the drive motor to increase as the pedal travel of the brake pedal of the electric vehicle increases; controlling the damping increase value of the suspension to increase as the pedal travel of the brake pedal of the electric vehicle increases.

[0021] Through the above method, when controlling the compensating torque output by the drive motor and the damping increase value of the suspension to increase with the increase of the pedal stroke of the brake pedal, the compensating torque output by the drive motor and the damping increase value of the suspension can be accurately controlled, thereby improving the effect of suppressing the jerking phenomenon of the electric vehicle.

[0022] In one embodiment, the above-mentioned control method specifically includes: at a second moment, during the braking process of the electric vehicle decelerating at a first deceleration, controlling the drive motor to output a first compensation torque and controlling the suspension to increase a first damping; at a second moment, during the braking process of the electric vehicle decelerating at a second deceleration, controlling the drive motor to output a second compensation torque and controlling the suspension to increase a second damping; wherein, the first deceleration is smaller than the second deceleration, the first compensation torque is smaller than the second compensation torque, and the first damping is smaller than the second damping.

[0023] Through the above method, when controlling the compensating torque output by the drive motor and the damping increase value of the suspension to increase with the increase of deceleration, the compensating torque output by the drive motor and the damping increase value of the suspension can be accurately controlled, thereby improving the effect of suppressing the jerking phenomenon of the electric vehicle.

[0024] In one embodiment, the control method further includes: during the process of braking the electric vehicle by the braking device, in response to the deceleration of the electric vehicle being greater than or equal to a preset deceleration, controlling the compensation torque output by the drive motor to zero and controlling the damping increase value of the suspension to zero.

[0025] In the above manner, during the braking process of the electric vehicle, when the deceleration of the electric vehicle is greater than or equal to the preset deceleration, it indicates that the braking mode of the electric vehicle is emergency braking, that is, the speed of the electric vehicle needs to be reduced rapidly. When the braking mode of the electric vehicle is emergency braking, the braking response speed of the electric vehicle is prioritized rather than braking comfort. Therefore, the vehicle controller will not control the compensating torque output by the drive motor and control the suspension to increase damping, thereby ensuring the braking speed and braking safety of the electric vehicle.

[0026] In the second aspect, an embodiment of the present application provides a vehicle controller for sensorless braking control of an electric vehicle, wherein the vehicle controller is used to control the output torque of a drive motor of the electric vehicle to drive the four wheels of the electric vehicle and to control the output damping of the suspension of the electric vehicle to reduce the jerking of the electric vehicle. The vehicle controller is specifically used to: during the braking process of the electric vehicle, in response to the deceleration of the electric vehicle being less than a preset deceleration and the speed of the electric vehicle being less than a preset speed, control the drive motor to output a compensation torque and control the suspension to increase damping; wherein the direction of the compensation torque is the same as the direction of the rotation speed of the wheels of the electric vehicle.

[0027] In one embodiment, the vehicle controller is specifically used to: during the braking process of the electric vehicle, in response to a decrease in the speed reduction rate of the drive motor, control the drive motor to increase the compensation torque and control the suspension to increase the damping.

[0028] In one embodiment, the vehicle controller is specifically used to: during the braking process of the electric vehicle, in response to a decrease in the speed reduction rate of the drive motor, control the drive motor to increase the compensation torque and control the suspension to increase the damping.

[0029] In a third aspect, an embodiment of the present application provides an electric vehicle, which includes a drive motor, a suspension, and a vehicle controller provided in the second aspect, and the vehicle controller is used to control the drive motor and the suspension to execute the control method described in the first aspect or any possible implementation of the first aspect.

[0030] Regarding the technical principles and technical effects of the above-mentioned second and third aspects, reference may be made to the relevant description of the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of an electric vehicle 1 provided in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of the architecture of an electric vehicle 1 provided in an embodiment of the present application;

[0033] Figure 3 Another schematic diagram of the architecture of the electric vehicle 1 provided in the embodiment of the present application;

[0034] Figure 4 A schematic diagram of a control process of a vehicle controller 510 of an electric vehicle 1 provided in an embodiment of the present application;

[0035] Figure 5 A schematic diagram of a control process of a motor controller 110 of an electric vehicle 1 provided in an embodiment of the present application;

[0036] Figure 6 A schematic diagram of an operation of a braking control process of an electric vehicle 1 provided in an embodiment of the present application;

[0037] Figure 7 Another operating schematic diagram of the braking control process of the electric vehicle 1 provided in an embodiment of the present application;

[0038] Figure 8 A schematic diagram of the operation of the electric vehicle 1 in the emergency braking mode provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The implementation and use of each embodiment will be discussed in detail below. However, it should be understood that many applicable inventive concepts provided by this application can be implemented in a variety of specific environments. The specific embodiments discussed only illustrate the specific ways to implement and use this application and this technology, and do not limit the scope of this application.

[0040] With the development of electric vehicles, the driving experience of vehicles has received more and more attention. Among them, the braking performance of vehicles is a key factor affecting the driving experience of vehicles. During the vehicle braking process, the late braking period refers to the process in which the vehicle speed decreases from very small to zero, that is, the process in which the vehicle stops completely and there is no relative movement with the ground. During the vehicle braking process, the suspension of the vehicle is compressed under the action of deceleration. After the vehicle braking is completed, although the vehicle has actually stopped, the body of the vehicle will rebound under the action of the suspension, causing the vehicle to jerk, affecting the user's driving experience.

[0041] In one possible implementation, at the end of the electric vehicle's braking, the brake device is controlled to release a certain amount of wheel-end braking force to reduce the electric vehicle's deceleration, thereby suppressing the shaking phenomenon during the electric vehicle's braking process. However, due to the current sensorless braking algorithm, the wheel-end signal transmission path is long and the time delay is large, which will cause the braking performance of the electric vehicle to decline.

[0042] In one possible implementation, the driving motor of the electric vehicle is controlled to brake without sense at the end of the braking of the electric vehicle, and the driving motor is controlled to output driving torque to reduce the deceleration of the whole vehicle, thereby suppressing the shaking phenomenon of the electric vehicle during braking. However, when the deceleration of the electric vehicle is adjusted, the electric vehicle undergoes load transfer, that is, the position of the weight (load) of the electric vehicle moves, so that the suspension of the electric vehicle has a poor effect of suppressing the vibration of the electric vehicle body when the driving motor outputs torque, resulting in the electric vehicle still having obvious setbacks.

[0043] In order to solve the above problems, the embodiments of the present application provide a control method for electric vehicle non-sensing braking and a vehicle controller for electric vehicle. During the braking process of the electric vehicle, the driving motor and suspension of the electric vehicle are controlled to reduce the setback of the electric vehicle during the braking process, thereby improving the driving experience of the user.

[0044] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0045] See also Figure 1 , Figure 1 Schematic diagram of an electric vehicle 1 provided in an embodiment of the present application. Figure 1 As shown, the electric vehicle 1 includes a driving system 100 , a suspension system 200 , a braking system 300 and a power battery 400 , and the power battery 400 is used to supply power to the driving system 100 , the suspension system 200 and the braking system 300 .

[0046] The operating state of the electric vehicle 1 includes a driving state and a braking state. When the electric vehicle 1 is in the driving state, the driving system 100 is used to receive power from the power battery 400 and provide the four wheels of the electric vehicle 1 with a driving torque in the same direction as the wheel speed, so that the electric vehicle 1 can travel under the drive of the driving torque; when the electric vehicle 1 is in the braking state, the braking system 300 is used to receive power from the power battery 400 and provide the four wheels of the electric vehicle 1 with a braking force in the opposite direction to the wheel speed, so that the electric vehicle 1 can slow down or stop under the action of the braking force.

[0047] The suspension system 200 connects the body and multiple wheels of the electric vehicle 1. The suspension system 200 is specifically used to transmit forces and torques between the wheels and the body, mitigate the impact caused by road bumps, attenuate the vibration of the electric vehicle 1 during driving, suppress the jerking phenomenon of the electric vehicle 1 during braking, and ensure that the wheels can maintain good contact with the road under various working conditions, thereby ensuring the vehicle's ride comfort, handling stability and driving safety.

[0048] It is understandable that the electric vehicle 1 in the embodiment of the present application can be any one of different types of vehicles such as a car, a truck, a passenger bus, etc., and can also be a transport device for carrying people or goods such as a tricycle, a two-wheeled vehicle, a train, or other types of vehicles driven by power batteries, which are not limited here. Among them, vehicles include but are not limited to pure electric vehicles (pure electric vehicle / battery electric vehicle, pure EV / battery EV), hybrid electric vehicles (hybrid electric vehicle, HEV), range extended electric vehicles (range extended electric vehicle, REEV), plug-in hybrid electric vehicles (plug-in hybrid electric vehicle, PHEV), new energy vehicles (new energy vehicle, NEV), etc.

[0049] It is understandable that the power battery 400 in the embodiment of the present application can be a lithium-ion battery, a lithium metal battery, a lead-acid battery, a nickel-cadmium battery, a nickel-hydrogen battery, a lithium-sulfur battery, a lithium-air battery or a sodium-ion battery, etc., which is not limited here. In terms of scale, the power battery 400 in the embodiment of the present application can be a single cell, or a battery module or a battery pack, which is not limited here. The power battery 400 can also power other electrical devices in the electric vehicle 1, such as the air conditioner in the vehicle, the car player, etc.

[0050] See also Figure 2 , Figure 2 The schematic diagram of the structure of the electric vehicle 1 provided in the embodiment of the present application is as follows: the driving system 100 , the suspension system 200 , and the braking system 300 are connected in communication with the vehicle controller 510 .

[0051] In one embodiment, the drive system 100 includes a motor controller 110 and a drive motor 120. The motor controller 110 is used to receive direct current output by the power battery 400 and output alternating current to control the drive motor 120 to output a driving torque so that the four wheels of the electric vehicle 1 rotate under the action of the driving torque.

[0052] The motor controller 110 in the drive system 100 can change the stator magnetic field strength and direction by adjusting the magnitude of the stator winding current and the phase of the three-phase current, thereby changing the interaction force between the stator and the rotor (i.e., the torque output by the motor). The motor controller 110 can also increase or decrease the drive torque output by the drive motor 120 by changing the magnitude of the three-phase current output to the drive motor 120. Among them, the motor controller 110 can be a microcontroller unit (MCU), and the motor controller 110 can also be a device in which a microcontroller and a vehicle control unit 510 (VCU) are integrated into one, etc., which is not limited here.

[0053] The suspension system 200 includes a suspension controller 210, an elastic element ( Figure 2 The damping of the suspension system 200 is adjusted by adjusting the damping of the shock absorber 220 in the suspension system 200. The elastic element is used to support the vertical load and suppress the vibration and impact caused by the uneven road surface; the shock absorber 220 is used to convert the vibration energy into heat energy and dissipate it through the flow of oil or gas inside it, so that the vehicle body can quickly return to a stable state. The shock absorber 220 is mainly composed of a cylinder, a piston, a piston rod and damping oil. The piston divides the cylinder into two upper and lower chambers. When the suspension of the electric vehicle 1 is impacted and the piston moves up and down in the cylinder, the damping oil will flow between the two chambers through the valve on the piston. The damping of the shock absorber 220 can be adjusted by adjusting the opening of the valve. Among them, the greater the damping of the shock absorber 220, the faster the shock absorber 220 can suppress the vibration after the elastic element rebounds, allowing the vehicle body to quickly return to a stable state; the smaller the damping of the shock absorber 220, the longer the duration of the vibration generated by the rebound of the elastic element when the electric vehicle 1 passes through a bumpy road, and the vehicle body may experience continuous up and down shaking.

[0054] The brake system 300 includes a brake controller 310, a brake pedal ( Figure 2) and a braking device 320, which is used to brake the four wheels of the electric vehicle 1. When the user steps on the brake pedal of the electric vehicle 1, the brake controller 310 generates a braking signal according to the pedal stroke of the brake pedal or the opening of the brake pedal, and the braking device 320 outputs a braking force to the corresponding wheel of the electric vehicle 1 according to the braking value indicated by the braking signal to reduce the speed of the electric vehicle 1. During the braking process of the electric vehicle 1, the greater the stroke of the brake pedal (or the opening of the brake pedal), the greater the braking value indicated by the braking signal, the greater the braking force output by the braking device 320, and the greater the deceleration of the electric vehicle 1, that is, the faster the speed of the electric vehicle 1 decreases. Among them, the brake controller 310 in the braking system 300 can be a microcontroller or a vehicle controller 510, and the brake controller 310 can also be integrated with the motor controller 110 in the drive system 100 to form a domain control unit (DCU) in the electric vehicle 1, which is not limited here. The brake device 320 may be an electronic hydraulic brake (EHB) or an electronic mechanical brake (EMB) or other types of brake devices 320 , which are not limited herein.

[0055] In one embodiment, when the electric vehicle 1 is in a braking state, the vehicle controller 510 calculates the torque demand of the electric vehicle 1 according to the speed and deceleration of the electric vehicle 1 and outputs a torque signal to the motor controller 110. The drive system 100 receives power from the power battery 400 and provides the four wheels of the electric vehicle 1 with a compensation torque in the same direction as the rotation speed of the wheels of the electric vehicle 1, so that the deceleration of the electric vehicle 1 during braking is reduced under the action of the compensation torque, thereby reducing the jerking phenomenon of the electric vehicle 1 during braking.

[0056] When the drive motor 120 in the drive system 100 outputs a compensating torque to reduce the deceleration of the electric vehicle 1, the electric vehicle 1 will experience load transfer, that is, the loads of the front axle and the rear axle of the electric vehicle 1 will change, for example, the load will be relatively transferred to the rear axle, resulting in the suspension system 200 having difficulty in effectively suppressing the vibration of the body of the electric vehicle 1 after the torque compensation. For example: if the vehicle controller 510 controls the suspension system 200 to increase the damping of the shock absorber 220 according to the signal detected by the sensor of the electric vehicle 1 after the motor controller 110 controls the drive motor 120 to output the compensating torque, it will cause the suspension system 200 to control the suspension system 200 to increase the damping, and it will be difficult for the suspension system 200 to suppress the longitudinal vibration caused by the load transfer of the electric vehicle 1, so that the electric vehicle 1 will experience a setback when the drive motor 120 outputs the compensating torque, affecting the user's driving experience.

[0057] In this embodiment, the damping is increased by intervening in advance to control the suspension, that is, the vehicle controller 510 controls the drive system 100 and the suspension system 200 in linkage. When the vehicle controller 510 instructs the motor controller 110 to control the drive motor 120 to output the compensation torque, the vehicle controller 510 is also used to simultaneously instruct the suspension controller 210 to control the shock absorber 220 to increase the damping, so that when the drive system 100 provides the compensation torque for the electric vehicle 1, the suspension system 200 can provide damping compensation for the electric vehicle 1, so that when the deceleration of the electric vehicle 1 changes during braking, the suspension system 200 can better suppress the jerking of the electric vehicle 1, thereby further reducing the jerking phenomenon of the electric vehicle 1 during braking and improving the user's driving experience.

[0058] In one embodiment, the electric vehicle 1 further includes a speed measurement unit 520, which is used to detect the speed of the drive motor 120. The speed measurement unit 520 can be set on the drive motor 120 (for example, on the rotor of the motor), and at this time, the motor controller 110 can receive the rotary signal and the speed signal of the drive motor 120 from the speed measurement unit 520. Exemplarily, the speed measurement unit 520 can be a rotary transformer, a motor speed sensor, etc. The rotary transformer is used to detect the speed and rotor position of the drive motor 120, and the motor speed sensor is used to detect the speed of the drive motor 120.

[0059] Among them, the speed signal can be indirectly obtained from the rotary signal. By processing the rotary signal and calculating the change in angle per unit time, the speed signal can be obtained. The rotary acceleration signal (angular acceleration signal) is the first-order derivative of the speed signal with respect to time. The rotary acceleration signal can be obtained by directly deriving the speed signal or approximating the derivation using the differential method. In addition, since the rotary signal can accurately reflect the speed of the motor, for the electric vehicle 1, the rotational motion of the motor is transmitted to the wheel through the transmission system, so that the electric vehicle 1 can travel. Due to the existence of the transmission ratio, there is a fixed proportional relationship between the speed of the drive motor 120 and the wheel speed. According to the transmission ratio corresponding to the drive motor 120 and the motor, the speed of the wheel can be calculated, and the speed of the electric vehicle 1 is directly related to the wheel speed. The vehicle speed can be calculated through the wheel speed and related parameters of the wheel (such as the wheel radius).

[0060] The electric vehicle 1 further includes an inertial measurement unit 530, which is used to detect the acceleration of the electric vehicle 1. The drive system 100 is used to adjust the compensation torque output by the drive motor 120 during braking according to the acceleration of the electric vehicle 1 detected by the inertial measurement unit 530.

[0061] In one embodiment, the electric vehicle 1 further includes a pressure sensor 540, which is used to detect the damping of the shock absorber 220. The pressure sensor 540 can be set in the shock absorber 220. When the suspension of the electric vehicle 1 is impacted and the shock absorber 220 is working, the piston moves up and down in the cylinder, causing the damping oil to flow through the valve on the piston, thereby generating a damping force. The pressure sensor 540 can capture the pressure change when the damping oil passes through the valve on the piston. The smaller the opening of the valve, the greater the pressure drop of the damping oil through the valve on the piston detected by the pressure sensor 540, that is, the greater the damping of the shock absorber 220.

[0062] The drive system 100, the suspension system 200, the brake system 300, and the vehicle controller 510 can be connected to each other through a communication bus and exchange signals. The communication bus includes a controller area network (CAN) bus, a local interconnect network (LIN) bus, a high-speed fault-tolerant network protocol (Flexray), or other types of buses, which are not limited here.

[0063] In some embodiments, the vehicle controller 510 can obtain a driving mode signal through a communication bus, where the driving mode signal is used to indicate the current driving mode of the electric vehicle 1. For example, the driving mode may include one or more of a sports mode, a comfort mode, and an intelligent mode.

[0064] In one embodiment, the drive system 100, the suspension system 200, the brake system 300, the vehicle controller 510 and at least one sensor of the electric vehicle 1 are connected to each other through a communication bus. This method can transmit multiple signals on the same communication line, greatly improving the communication efficiency and reducing a large amount of separate wiring. For example, when the motor controller 110 is connected to the communication bus, the motor controller 110 may include a communication terminal, which can be connected to the communication bus. The motor controller 110 can obtain signals from the communication bus through the communication terminal. The signals of many sensors such as the wheel speed sensor, temperature sensor, and brake pedal position sensor in the electric vehicle 1 can be transmitted to the motor controller 110 through the bus. The motor controller 110 can obtain one or more signals such as the vehicle speed, torque signal, and brake signal from the communication bus; the motor controller 110 can also upload signals to the communication bus, such as one or more signals of the torque value and torque direction of the compensation torque output by the drive motor 120.

[0065] In one embodiment, the motor controller 110, the suspension controller 210, and the brake controller 310 are directly connected to the sensor. For some sensors that have extremely high requirements for signal stability and real-time performance, direct connection can reduce interference and delay during signal transmission. For example, the motor controller 110 can be directly connected to the above-mentioned speed measurement unit 520, and the motor controller 110 can determine the speed of the drive motor 120, the speed of the electric vehicle 1, the acceleration (or deceleration) of the electric vehicle 1, etc. based on the received rotational signal of the drive motor 120; the motor controller 110 can determine the speed of the drive motor 120 based on the received speed signal of the drive motor 120.

[0066] Figure 3 Another schematic diagram of the structure of the electric vehicle 1 provided in the embodiment of the present application. Figure 3 As shown, the electric vehicle 1 further includes four wheels 130 , namely a left front wheel LF and a right front wheel RF corresponding to a front axle 140 of the electric vehicle 1 , and a left rear wheel LR and a right rear wheel RR corresponding to a rear axle 150 of the electric vehicle 1 .

[0067] The driving system of the electric vehicle 1 may be a centralized drive motor driving architecture, in which two drive motors 120 for driving two front wheels or two drive motors 120 for driving two rear wheels are arranged together. The driving system may also be a wheel-side four-drive motor driving architecture, in which the drive motor 120 is arranged at the wheel 130 driven by the drive motor 120 and is controlled by a separate motor controller 110. The motor controller 110 may be one or more, and the motor controller 110 and the drive motor 120 may correspond one to one, or one motor controller 110 may correspond to multiple drive motors 120. The motor controller 110 is used to control one or more drive motors 120 to output torque to drive the electric vehicle 1.

[0068] The elastic element ( Figure 3 The shock absorber is used to transmit the force and torque between the wheel 130 and the vehicle body, mitigate the impact caused by road bumps, and suppress the setback phenomenon during the braking process of the electric vehicle 1. Figure 3 (a) to Figure 3 As shown in (c), the suspension system of the electric vehicle 1 includes a suspension controller 210, a front suspension 230 and a rear suspension 240, each of which includes an elastic element and a shock absorber. The front suspension 230 is connected to the front axle 140, and is used to support, guide and buffer the left front wheel LF and the right front wheel RF. The rear suspension 240 is connected to the rear axle 150, and is used to support, guide and buffer the left rear wheel LR and the right rear wheel RR.

[0069] In some embodiments, the suspension controller 210 in the suspension system may be one or more, and the suspension controller 210 and the shock absorber may correspond one to one, or one suspension controller 210 may correspond to multiple shock absorbers. The suspension controller 210 is used to adjust the damping of one or more shock absorbers to attenuate the vibration of the electric vehicle 1 during driving.

[0070] In one embodiment, if Figure 3 As shown in (a), the driving system of the electric vehicle 1 is a centralized drive motor drive architecture, and the vehicle is driven by a single drive motor 120, that is, the electric vehicle 1 is a single-drive form of a front-mounted front-wheel drive (the drive motor 120 is used to drive the two front wheels) or a rear-mounted rear-wheel drive (the drive motor 120 is used to drive the two rear wheels) vehicle.

[0071] like Figure 3 As shown in (a), when the electric vehicle 1 is a front-engine front-wheel drive vehicle, the motor controller 110 is used to control the drive motor 120 to output the drive torque, and the drive torque generated by the drive motor 120 is transmitted to the two front wheels through the transmission system to drive the left front wheel LF and the right front wheel RF corresponding to the front axle 140 to rotate. The two rear wheels (left rear wheel LR and right rear wheel RR) of the electric vehicle 1 are driven wheels, and the two rear wheels are driven to rotate by the friction with the ground and the overall movement trend of the electric vehicle 1.

[0072] In one embodiment, if Figure 3 As shown in (b) , the driving system of the electric vehicle 1 is a centralized driving motor driving architecture, and the driving system includes a motor controller 110 and two driving motors. The four wheels 130 of the electric vehicle 1 are driven by the driving motor 121 and the driving motor 122 .

[0073] The drive motor 121 is used to drive the left front wheel LF and the right front wheel RF corresponding to the front axle 140 of the electric vehicle 1, and the drive motor 122 is used to drive the left rear wheel LR and the right rear wheel RR corresponding to the rear axle 150 of the electric vehicle 1. The motor controller 110 is used to control the drive motor 121 to output the front drive compensation torque so that the two front wheels rotate under the action of the front drive compensation torque, and the motor controller 110 is also used to control the drive motor 122 to output the rear drive compensation torque so that the two rear wheels rotate under the action of the rear drive compensation torque.

[0074] In some embodiments, the drive system may include two motor controllers 110 ( Figure 3 (b) not shown), drive motor 121 and drive motor 122, the motor controller 110 corresponds to the drive motor one by one, and each motor controller 110 is used to control the drive motor corresponding to each motor controller 110 to output the drive torque so that each drive motor drives the two wheels 130 corresponding to each drive motor.

[0075] In one embodiment, if Figure 3 As shown in (c) , the driving system of the electric vehicle 1 is a wheel-side four-drive motor driving architecture, and the driving system includes a motor controller 110 and four drive motors, each of which is used to drive a wheel 130 of the electric vehicle 1 .

[0076] In this embodiment, the drive motor 123 is used to drive the left front wheel LF of the electric vehicle 1, the drive motor 124 is used to drive the right front wheel RF of the electric vehicle 1, the drive motor 125 is used to drive the left rear wheel LR of the electric vehicle 1, and the drive motor 126 is used to drive the right rear wheel RR of the electric vehicle 1. The motor controller 110 is used to control the four drive motors to output drive torque so that each drive motor drives the wheel 130 corresponding to each drive motor.

[0077] In one embodiment, the drive system includes four motor controllers 110 ( Figure 3 (c) (not shown) and four drive motors, four motor controllers 110 correspond one to one with the four drive motors, and each motor controller 110 is used to control the drive motor corresponding to each motor controller 110 to output a drive torque so that each drive motor drives the wheel 130 corresponding to each drive motor.

[0078] In one embodiment, the drive system may also be combined with the various architectures mentioned above, such as a wheel-side drive motor architecture for the front drive and a centralized drive motor architecture for the rear drive, which is not limited here.

[0079] The above describes the architecture of the embodiment of the present application. The following is an exemplary description of the control process of the main controller (vehicle controller) in the braking control process of the electric vehicle 1. In the embodiment of the present application, after the senseless braking mode is started and the brake controller 310 controls the four brake devices 320 to brake the four wheels 130 of the electric vehicle 1, the main controller for implementing the braking control process of the electric vehicle 1 can be the vehicle controller 510, the motor controller 110 or the domain controller, which is not limited here.

[0080] In some embodiments, the user may pre-select to enable the senseless braking mode, wherein the user enables the senseless braking mode in the following ways: selecting to enable the senseless braking mode in the human-vehicle interaction system; enabling by pressing the senseless braking mode button; selecting to enable the senseless braking mode in a terminal device connected to the electric vehicle 1 by wire or wirelessly, etc., without limitation herein. Whether the electric vehicle 1 enters the senseless braking mode at the end of braking when it enters the non-emergency braking mode is determined by the user's choice. The electric vehicle 1 automatically enters the senseless braking mode at the end of braking when the electric vehicle 1 enters the non-emergency braking mode based on the user's pre-selection to enable the senseless braking mode. In some embodiments, after the user selects to enable the senseless braking mode, the senseless braking mode is automatically enabled after the electric vehicle 1 is subsequently started, thereby simplifying user operations and improving user experience.

[0081] The braking of the electric vehicle 1 includes emergency braking and non-emergency braking. Emergency braking is a braking process in which the electric vehicle 1 is rapidly decelerated to a stop. During the emergency braking process, the deceleration of the electric vehicle 1 is relatively large. Non-emergency braking is a braking process in which the electric vehicle 1 is slowly decelerated to a stop. During the non-emergency braking process, the deceleration of the electric vehicle 1 is relatively small. Whether the braking mode of the electric vehicle 1 is an emergency braking mode or a non-emergency braking mode can be determined based on the deceleration of the electric vehicle 1, the brake pedal travel, or the speed reduction rate of the drive motor 120.

[0082] In one embodiment, during the braking process of the electric vehicle 1, if the deceleration of the electric vehicle 1 is greater than or equal to the preset deceleration, the braking mode of the electric vehicle 1 is the emergency braking mode. During the braking process of the electric vehicle 1, if the deceleration of the electric vehicle 1 is less than the preset deceleration, the braking mode of the electric vehicle 1 is the non-emergency braking mode. For example, the preset deceleration can be 5m / s 2 .

[0083] In one embodiment, when the speed reduction rate of the driving motor 120 during the braking process of the electric vehicle 1 is greater than or equal to a preset rate, the braking mode of the electric vehicle 1 is an emergency braking mode. When the speed reduction rate of the driving motor 120 during the braking process of the electric vehicle 1 is less than a preset rate, the braking mode of the electric vehicle 1 is a non-emergency braking mode.

[0084] In one embodiment, when the brake pedal stroke of the electric vehicle 1 is greater than or equal to a preset value during the braking process of the electric vehicle 1, the braking mode of the electric vehicle 1 is an emergency braking mode. When the brake pedal stroke of the electric vehicle 1 is less than a preset value during the braking process of the electric vehicle 1, the braking mode of the electric vehicle 1 is a non-emergency braking mode.

[0085] In the emergency braking mode, it is necessary to ensure that the electric vehicle 1 stops moving within the shortest possible distance to avoid collision, loss of control and other dangerous situations of the electric vehicle 1. Therefore, in the emergency braking mode, it is necessary to ensure the braking efficiency and braking safety of the electric vehicle 1. When the braking mode of the electric vehicle 1 is a non-emergency braking mode, in addition to considering the braking efficiency and braking safety of the electric vehicle 1, the braking comfort of the electric vehicle 1 and the driving experience of the user can also be considered.

[0086] The final stage of braking during the braking process is the process of the electric vehicle 1 stopping from a low speed. When the electric vehicle 1 is at the final stage of braking, the speed of the electric vehicle 1 during the braking process is less than the preset speed, or the speed of the driving motor 120 of the electric vehicle 1 during the braking process is less than the preset speed, which is not limited here.

[0087] In an embodiment of the present application, when the electric vehicle 1 enters the final stage of braking and the braking mode of the electric vehicle 1 is a non-emergency braking mode, the deceleration of the electric vehicle 1 at the final stage of braking is reduced by controlling the drive motor 120 of the electric vehicle 1 to output a compensating torque and controlling the suspension of the electric vehicle 1 to increase damping, thereby improving the suspension's ability to suppress vibrations during the braking process of the electric vehicle 1 and reducing the jerking phenomenon of the electric vehicle 1 at the final stage of braking, thereby improving the user's driving experience.

[0088] In one embodiment, when the main controller for implementing the braking control process of the electric vehicle 1 provided in the embodiment of the present application is the vehicle controller 510, it can be referred to Figure 4 , Figure 4 This is a schematic diagram of the control process of the vehicle controller 510 of the electric vehicle 1 provided in the embodiment of the present application. Take the electric vehicle 1 with a single drive motor 120 as an example.

[0089] At the first moment, after the brake controller 310 controls the brake device 320 to brake the four wheels 130 of the electric vehicle 1, the inertial measurement unit 530 of the electric vehicle 1 sends the detected acceleration signal to the vehicle controller 510, and the acceleration signal is used to indicate the deceleration of the electric vehicle 1. The speed measurement unit 520 of the drive motor 120 sends the detected speed signal to the motor controller 110, and the motor controller 110 forwards the speed signal to the vehicle controller 510, and the speed signal is used to indicate the speed of the drive motor 120. The pressure sensor 540 of the shock absorber 220 sends the detected damping signal to the suspension controller 210, and the suspension controller 210 forwards the damping signal to the vehicle controller 510, and the damping signal is used to indicate the damping of the shock absorber 220.

[0090] At the second moment after the first moment, the vehicle controller 510 obtains vehicle status information such as the deceleration of the electric vehicle 1, the speed of the drive motor 120 and the damping of the shock absorber 220 in the suspension according to the vehicle's sensors. If it is detected that the deceleration of the electric vehicle 1 is less than the preset deceleration and the speed of the drive motor 120 is less than the preset speed, it is determined that the electric vehicle 1 is in a non-emergency braking state and the electric vehicle 1 is in the terminal stage of braking.

[0091] The motor controller 110 serves as a slave controller of the vehicle controller 510. The vehicle controller 510 is used to send a torque control instruction to the motor controller 110. The torque control instruction is used to indicate the torque value of the compensation torque, so that the motor controller 110 outputs a torque control signal according to the torque control instruction to control the drive motor 120 to output the compensation torque, thereby reducing the deceleration of the electric vehicle 1.

[0092] The suspension controller 210 serves as a slave controller of the vehicle controller 510. The vehicle controller 510 is also used to send a damping control instruction to the suspension controller 210 at the same time. The damping control instruction is used to indicate the damping value so that the suspension controller 210 outputs a damping control signal according to the damping control instruction to control the shock absorber 220 to increase the damping.

[0093] exist Figure 4 In the embodiment, the electric vehicle 1 is also used to form a feedforward through the speed signal of the drive motor 120. Due to factors such as road surface excitation (such as uneven road surface, uphill road or downhill road), driving conditions (such as turning, acceleration, deceleration, etc.), etc., the electric vehicle 1 has load transfer, which acts on the wheel 130, causing the road adhesion of the wheel 130 to fluctuate in real time, so that the actual braking torque of the wheel 130 deceleration is inconsistent with the braking torque of the wheel 130 under the action of the braking torque of the brake device 320 and the compensation torque, which leads to a difference between the actual decrease rate of the speed of the drive motor 120 (i.e., the deceleration of the electric vehicle 1) and the ideal decrease rate when the drive motor 120 outputs the compensation torque. The vehicle controller 510 detects the speed change of the drive motor 120 based on the speed signal output by the inertial measurement unit 530 to perceive and observe the change of the road adhesion of the electric vehicle 1, so that the motor controller 110 can actively adjust the torque actually output by the drive motor 120 according to the speed signal of the drive motor 120.

[0094] In this embodiment, the vehicle controller 510 uses the torque signal and the speed signal to form a proximal closed loop when controlling the drive motor 120, that is, the vehicle controller 510 is used to periodically receive the torque signal and the speed signal returned by the motor controller 110, and the vehicle controller 510 adjusts the torque value of the compensation torque indicated by the torque control instruction output to the motor controller 110 according to the torque signal and the speed signal. For example: the vehicle controller 510 detects that the speed reduction rate of the drive motor 120 decreases (the deceleration of the electric vehicle 1 decreases) according to the speed signal, and the torque value of the compensation torque indicated by the torque control instruction output by the vehicle controller 510 to the motor controller 110 decreases; the vehicle controller 510 detects that the speed reduction rate of the drive motor 120 increases (the deceleration of the electric vehicle 1 increases) according to the speed signal, and the torque value of the compensation torque indicated by the torque control instruction output by the vehicle controller 510 to the motor controller 110 increases.

[0095] Since the vehicle controller 510 will cause load transfer in the electric vehicle 1 when adjusting the compensation torque output by the drive motor 120, in order to ensure that the suspension of the electric vehicle 1 can suppress the vibration of the body of the electric vehicle 1 when the drive motor 120 outputs torque, the vehicle controller 510 needs to perform closed-loop control on the suspension damping while performing closed-loop control on the compensation torque output by the drive motor 120.

[0096] In this embodiment, the vehicle controller 510 is also used to form a proximal closed loop using a damping signal and a speed signal when controlling the suspension, that is, the vehicle controller 510 is used to periodically receive a torque signal and a speed signal returned by the motor controller 110 and a damping signal returned by the suspension controller 210, and the vehicle controller 510 adjusts the damping value indicated by the damping control instruction output to the suspension controller 210 according to the torque signal, the speed signal and the damping signal. For example: the vehicle controller 510 detects that the speed reduction rate of the drive motor 120 decreases (the deceleration of the electric vehicle 1 decreases) according to the speed signal, and the damping value indicated by the damping control instruction output by the vehicle controller 510 to the suspension controller 210 increases; the vehicle controller 510 detects that the speed reduction rate of the drive motor 120 increases (the deceleration of the electric vehicle 1 increases) according to the speed signal, and the damping value indicated by the damping control instruction output by the vehicle controller 510 to the suspension controller 210 increases.

[0097] In one embodiment, when the main controller for implementing the braking control process of the electric vehicle 1 is the motor controller 110, Figure 5 , Figure 5 This is a schematic diagram of a control process of a motor controller 110 of an electric vehicle 1 provided in an embodiment of the present application. Take the electric vehicle 1 as an example, which is a vehicle with a single drive motor 120.

[0098] At the first moment, after the brake controller 310 controls the brake device 320 to brake the four wheels 130 of the electric vehicle 1, the inertial measurement unit 530 of the electric vehicle 1 sends the detected acceleration signal to the vehicle controller 510, and the vehicle controller 510 forwards the acceleration signal to the motor controller 110, and the acceleration signal is used to indicate the deceleration of the electric vehicle 1. The speed measurement unit 520 of the drive motor 120 sends the detected speed signal to the motor controller 110, and the speed signal is used to indicate the speed of the drive motor 120. The pressure sensor 540 of the shock absorber 220 sends the detected damping signal to the suspension controller 210, and the suspension controller 210 forwards the damping signal to the motor controller 110, and the damping signal is used to indicate the damping of the shock absorber 220.

[0099] At the second moment after the first moment, the motor controller 110 obtains vehicle status information such as the deceleration of the electric vehicle 1, the speed of the drive motor 120 and the damping of the shock absorber 220 in the suspension according to the vehicle's sensors. If it is detected that the deceleration of the electric vehicle 1 is less than the preset deceleration and the speed of the drive motor 120 is less than the preset speed, it is determined that the electric vehicle 1 is in a non-emergency braking state and the electric vehicle 1 is in the terminal stage of braking.

[0100] The motor controller 110 is used to send a torque control signal to the drive motor 120 , where the torque control signal is used to indicate a torque value of the compensation torque so that the drive motor 120 outputs the compensation torque, thereby reducing the deceleration of the electric vehicle 1 .

[0101] The suspension controller 210 serves as a slave controller of the motor controller 110. The motor controller 110 is also used to send a damping control instruction to the suspension controller 210 at the same time. The damping control instruction is used to indicate the damping value so that the suspension controller 210 outputs a damping control signal according to the damping control instruction to control the shock absorber 220 to increase the damping.

[0102] exist Figure 5In the embodiment, the motor controller 110 uses the torque signal and the speed signal to form a proximal closed loop when controlling the drive motor 120, that is, the vehicle controller 510 is used to periodically receive the torque signal and the speed signal, and the motor controller 110 adjusts the torque value of the compensation torque indicated by the torque control signal output to the motor controller 110 according to the torque signal and the speed signal. For example: the motor controller 110 detects that the speed reduction rate of the drive motor 120 decreases (the deceleration of the electric vehicle 1 decreases) according to the speed signal, and the torque value of the compensation torque indicated by the torque control signal output by the motor controller 110 to the motor controller 110 decreases; the motor controller 110 detects that the speed reduction rate of the drive motor 120 increases (the deceleration of the electric vehicle 1 increases) according to the speed signal, and the torque value of the compensation torque indicated by the torque control signal output by the motor controller 110 to the motor controller 110 increases.

[0103] In this embodiment, the motor controller 110 is also used to form a proximal closed loop using a damping signal and a speed signal when controlling the suspension, that is, the motor controller 110 is used to periodically receive a torque signal, a speed signal and a damping signal returned by the suspension controller 210, and the motor controller 110 adjusts the damping value indicated by the damping control instruction output to the suspension controller 210 according to the torque signal, the speed signal and the damping signal. For example: the motor controller 110 detects that the speed reduction rate of the drive motor 120 decreases (the deceleration of the electric vehicle 1 decreases) according to the speed signal, and the damping value indicated by the damping control instruction output by the motor controller 110 to the suspension controller 210 increases; the motor controller 110 detects that the speed reduction rate of the drive motor 120 increases (the deceleration of the electric vehicle 1 increases) according to the speed signal, and the damping value indicated by the damping control instruction output by the motor controller 110 to the suspension controller 210 increases.

[0104] Combine the following Figure 6 to Figure 7 An exemplary description is given of how to consider various factors to coordinately control the drive motor 120 and the suspension system 200 to achieve a senseless braking.

[0105] like Figure 6 As shown, Figure 6 An operating schematic diagram of the braking control process of the electric vehicle 1 provided in an embodiment of the present application.

[0106] During the driving process of the electric vehicle 1 , the electric vehicle 1 runs normally, the brake controller 310 controls the braking force output by the brake device 320 to be 0, and the deceleration a of the electric vehicle 1 is 0.

[0107] At the first moment t1, the user steps on the brake pedal, and the electric vehicle 1 enters the braking process. The brake controller 310 controls the brake device 320 to brake the four wheels 130 of the electric vehicle 1. The speed v of the electric vehicle 1 (the speed n of the drive motor 120) decreases under the action of the braking force output by the brake system 300, and the decreasing rate of the speed n of the drive motor 120 increases with the increase of the braking force. Among them, the braking force output by the brake device 320 controlled by the brake controller 310 increases with the increase of the pedal stroke of the brake pedal, and the deceleration a of the electric vehicle 1 during the braking process increases with the increase of the braking force.

[0108] The vehicle controller can receive a speed signal (such as a resolver signal) of the drive motor 120 from a speed measurement unit 520 (such as a resolver), and obtain the speed n of the drive motor 120 and the speed v of the electric vehicle 1 based on the speed signal; the vehicle controller can also receive an acceleration signal of the electric vehicle 1 from the inertia detection unit, and obtain the acceleration (or deceleration a) of the electric vehicle 1 based on the acceleration signal.

[0109] At the second moment t2 after the first moment t1, during the process of the brake device 320 braking the four wheels 130 of the electric vehicle 1, since the vehicle speed v of the electric vehicle 1 gradually decreases during the continuous braking process, if the vehicle controller detects that the deceleration a of the electric vehicle 1 during the braking process is less than the preset deceleration a1 and the vehicle speed v is less than the preset vehicle speed v1 according to the acceleration signal and the resolver signal of the electric vehicle 1, the vehicle controller determines that the electric vehicle 1 enters the end of the braking in the non-emergency braking mode. In this embodiment, at the second moment t2, the vehicle controller is used to control the drive motor 120 to output the compensation torque T and control the suspension to increase the damping F, wherein the direction of the compensation torque T is the same as the direction of the rotation speed n of the wheel 130 of the electric vehicle 1, so as to reduce the deceleration a of the electric vehicle 1.

[0110] The following describes how the vehicle controller determines the magnitude of the compensation torque T output by the drive motor 120 and determines the magnitude of the increased damping F of the suspension.

[0111] During the braking process of the electric vehicle 1, the electric vehicle 1 controls the braking device 320 of the electric vehicle 1 to output the braking force according to the braking value indicated by the braking signal output by the vehicle controller. However, during the process in which the vehicle controller controls the drive motor 120 to output the compensation torque T and controls the suspension to increase the damping F, the vehicle controller needs to determine the torque value of the compensation torque T output by the drive motor 120 according to the vehicle speed v and / or deceleration a of the electric vehicle 1, and at the same time determine the increase value of the damping F when the suspension increases the damping F according to the vehicle speed v and / or deceleration a of the electric vehicle 1.

[0112] In one embodiment, the vehicle controller controls the compensation torque T output by the drive motor 120 and controls the damping F increased by the suspension to increase with the increase of the deceleration a of the electric vehicle 1. For example, at the second moment t2 after the first moment t1, during the braking process of the electric vehicle 1 decelerating at the first deceleration, the vehicle controller controls the drive motor 120 to output the first compensation torque and controls the suspension to increase the first damping; at the second moment t2 after the first moment t1, during the braking process of the electric vehicle 1 decelerating at the second deceleration, the vehicle controller controls the drive motor 120 to output the second compensation torque and controls the suspension to increase the second damping; wherein, the first deceleration is less than the second deceleration, the first compensation torque is less than the second compensation torque, and the first damping is less than the second damping.

[0113] In one embodiment, the vehicle controller controls the compensation torque T output by the drive motor 120 to increase with the increase of the pedal travel or pedal opening of the brake pedal. The vehicle controller is also used to control the increase value of the damping F of the suspension to increase with the increase of the pedal travel or pedal opening of the brake pedal.

[0114] In one embodiment, the vehicle controller can determine the compensation torque T and the increase value of the damping F of the electric vehicle 1 based on the comfort braking curve corresponding to the electric vehicle 1 as a reference curve. The comfort braking curve is a curve that describes the change of the ideal deceleration a over time during the braking process of the vehicle, so as to achieve smooth and comfortable braking of the electric vehicle 1.

[0115] The vehicle controller predetermines the comfortable braking curve of the electric vehicle 1, for example, by recording the speed curve and / or deceleration curve of the electric vehicle 1 in the process of gradually releasing the brake pedal when the electric vehicle 1 brakes and allowing the electric vehicle 1 to stop smoothly, and through multiple tests, draws the ideal speed curve and / or deceleration curve of the electric vehicle 1, which is the comfortable braking curve. Taking the comfortable braking curve of the electric vehicle 1 as the control basis, the electric vehicle 1 is braked as much as possible according to the comfortable braking curve when braking, which can not only improve the comfort of the driver and passengers, but also enhance the safety and stability of vehicle braking. During the braking process of the electric vehicle 1, the electric vehicle 1 may not be able to decelerate according to the desired comfortable braking curve due to the torque interference of its own transmission system or motor, and the deceleration a of the electric vehicle 1 is inconsistent with the ideal deceleration corresponding to the comfortable braking curve. If the deceleration a of the electric vehicle 1 is greater than the ideal deceleration corresponding to the comfortable braking curve of the electric vehicle 1 at the vehicle speed v, it indicates that the braking force of the electric vehicle 1 is too large. The vehicle controller controls the drive motor 120 to output a compensation torque T in the same direction as the rotation speed n of the wheel 130 of the electric vehicle 1 to reduce the deceleration a of the electric vehicle 1 so that the electric vehicle 1 brakes according to the comfortable braking curve.

[0116] At the second moment t2, the vehicle controller determines the compensation torque T of the electric vehicle 1 according to the deceleration a of the electric vehicle 1 at the second moment t2 and the ideal deceleration corresponding to the vehicle speed v of the electric vehicle 1 at the second moment t2 in the comfort braking curve. The greater the deceleration difference a2 between the deceleration a of the electric vehicle 1 and the ideal deceleration corresponding to the comfort braking curve, the greater the compensation torque T output by the drive motor 120 controlled by the vehicle controller.

[0117] Of course, other methods may also be used to calculate the compensation torque T, and the embodiment of the present application is not limited to this.

[0118] When the vehicle controller controls the drive motor 120 to output the compensation torque T so as to reduce the deceleration a of the electric vehicle 1, the load transfer will occur in the electric vehicle 1. In order to ensure the vibration suppression effect of the suspension on the body of the electric vehicle 1, the vehicle controller also needs to control the suspension to increase the damping F. However, if the vehicle controller controls the suspension to increase the damping F according to the compensation torque T output by the drive motor 120 after the drive motor 120 outputs the compensation torque T, that is, after the second moment t2, the suspension will not be able to adjust the state of the whole vehicle in time when the drive motor 120 outputs the compensation torque T at the second moment t2, causing the whole vehicle to experience obvious setbacks at the second moment t2.

[0119] In this embodiment, if Figure 6 As shown, at the second moment t2, the vehicle controller determines the compensation torque T output by the drive motor 120 based on the deceleration difference a2 between the deceleration a of the electric vehicle 1 and the ideal deceleration under the comfortable braking curve, and can also determine the torque increase value of the suspension based on the deceleration difference a2, that is, the vehicle controller predicts the load transfer that will occur in the whole vehicle when the deceleration a of the electric vehicle 1 is adjusted to the comfortable braking curve based on the deceleration difference a2, and implements early intervention to control the change of the damping F of the suspension, so that the vehicle controller can control the compensation torque T output by the drive motor 120 and control the suspension to increase the damping F. Since the direction of the compensation torque T is the same as the direction of the rotation speed n of the wheel 130 of the electric vehicle 1, the compensation torque T causes the electric vehicle 1 to generate acceleration, so that the rate of decrease of the vehicle speed v of the electric vehicle 1 is reduced, thereby reducing the frustration of the electric vehicle 1 caused by the fast rate of change of the vehicle speed v during the braking process. At the same time, the suspension provides damping F compensation for the electric vehicle 1, so that the suspension can better suppress the vibration of the electric vehicle 1, thereby further reducing the frustration of the electric vehicle 1 during the braking process.

[0120] In this embodiment, the vehicle controller controls the compensation torque T output by the drive motor 120 to increase with the increase of the deceleration difference a2, and the vehicle controller controls the damping F of the suspension to increase with the increase of the deceleration difference a2.

[0121] In one embodiment, a rotary transformer provided on the drive motor 120 obtains a rotary signal, and then the speed v and deceleration a of the electric vehicle 1 are determined based on the rotary signal, thereby improving the detection accuracy of the speed v and deceleration a of the electric vehicle 1. Since the rotary transformer has a high sampling frequency and the vehicle controller can directly obtain the rotary signal of the drive motor 120, the time delay for the vehicle controller to obtain the speed v and deceleration a of the electric vehicle 1 is reduced, so that the vehicle controller can quickly determine the compensation torque T based on the speed v and deceleration a of the electric vehicle 1, thereby reducing the control delay.

[0122] In one embodiment, the resolver signal obtained by the resolver is more sensitive than the vehicle speed v signal, but the resolver signal has a large fluctuation problem. In order to obtain a more accurate vehicle speed v, the vehicle dynamics model is combined, the speed n of the drive motor 120 and the measured vehicle speed v of the electric vehicle 1 are used as inputs, and the vehicle dynamics factors such as the mass, moment of inertia, and adhesion between the tire and the ground of the electric vehicle 1 are comprehensively considered, resulting in burrs (i.e., some abnormal amplitude fluctuations that occur in a short period of time) in the resolver signal output by the sensor. The resolver signal is filtered using a filtering algorithm (such as a Kalman filtering algorithm, a median filtering algorithm, etc.), so that the vehicle speed v signal obtained using the resolver signal is closer to the vehicle speed v of the electric vehicle 1. Among them, the Kalman filter algorithm can make the optimal estimate based on the uncertainty of the system (such as measurement noise, model error, etc.), so that the calculated vehicle speed v can have good performance in terms of accuracy and stability, thereby ensuring the accuracy of the compensation torque T of the drive motor 120 and the increase value of the damping F of the suspension determined by the rotary transformer signal of the electric vehicle 1, and improving the effect of suppressing the jerking phenomenon of the electric vehicle 1.

[0123] In one embodiment, the method of calculating the deceleration a of the electric vehicle 1 using the filtering algorithm is the same as the method of calculating the vehicle speed v of the electric vehicle 1 , which will not be described in detail herein.

[0124] By adopting this method, the tendency of the center of mass of the vehicle to move forward during braking and the vehicle jerking after parking can be reduced, thereby improving the comfort of the vehicle during braking. In addition, the vehicle controller is used to obtain signals by directly connecting to the vehicle's sensors, which effectively reduces the signal transmission time, thereby reducing the control delay and shortening the braking distance of the electric vehicle 1.

[0125] After the second moment t2, during the continuous braking process of the electric vehicle 1, due to the continuous changes in the operating conditions and external environment of the electric vehicle 1, such as road conditions, load changes, etc., the deceleration a of the electric vehicle 1 will change. At this time, it is necessary to adjust the compensation torque T of the drive motor 120 to ensure that the electric vehicle 1 can adapt to the changes in the driving conditions, to ensure that the deceleration curve of the electric vehicle 1 can be as close as possible to the ideal deceleration under the comfortable braking curve, and to adjust the damping F of the suspension synchronously to ensure the vibration suppression effect of the suspension on the electric vehicle 1. For example, when the electric vehicle 1 enters an uphill section, the decreasing rate of the rotation speed n of the drive motor 120 increases (the deceleration a of the electric vehicle 1 increases); when the electric vehicle 1 enters a downhill section, the decreasing rate of the rotation speed n of the drive motor 120 decreases (the deceleration a of the electric vehicle 1 decreases); when the electric vehicle 1 enters a bumpy section, the decreasing rate of the rotation speed n of the drive motor 120 fluctuates (the deceleration a of the electric vehicle 1 fluctuates).

[0126] At the third moment t3 after the second moment t2, when the vehicle controller detects that the rate of reduction of the speed n of the drive motor 120 decreases (the deceleration a of the electric vehicle 1 decreases) based on the resolver signal from the speed measurement unit 520 (such as a resolver) at the third moment t3, in order to ensure that the electric vehicle 1 can stably maintain the ideal deceleration under the comfort braking curve, the vehicle controller controls the compensation torque T output by the drive motor 120 to decrease, and controls the suspension to increase the damping F, that is, the vehicle controller controls the damping F of the suspension at the third moment t3 to be greater than the damping F of the suspension at the second moment t2.

[0127] In this embodiment, when the electric vehicle 1 enters a downhill section, the decreasing rate of the rotation speed n of the drive motor 120 decreases (the deceleration a of the electric vehicle 1 decreases); when the electric vehicle 1 enters a bumpy section, the decreasing rate of the rotation speed n of the drive motor 120 fluctuates (the deceleration a of the electric vehicle 1 fluctuates), and at the third moment t3, the decreasing rate of the rotation speed n of the drive motor 120 shows a decreasing trend. At the third moment t3, the vehicle controller controls the compensation torque T of the drive motor 120 to increase as the decreasing rate of the rotation speed n of the drive motor 120 decreases, and controls the damping F of the suspension to increase as the decreasing rate of the rotation speed n of the drive motor 120 decreases.

[0128] In this embodiment, the vehicle controller uses the actual difference between the actual deceleration a of the electric vehicle 1 (i.e., the actual rate of decrease of the rotational speed n of the drive motor 120) and the ideal deceleration corresponding to the electric vehicle 1 in the comfort braking curve as a feedback signal, so as to adjust the output torque of the drive motor 120 and the increase value of the damping F of the suspension in real time based on the actual difference in deceleration a, thereby realizing closed-loop control of the deceleration a of the electric vehicle 1.

[0129] In some embodiments, the vehicle controller can directly obtain the resolver signal from the sensor (such as a resolver), so that the vehicle controller can track the changes of the resolver signal of the electric vehicle 1 in real time. Since the sampling frequency of the resolver is high, the vehicle controller can improve the control bandwidth of the closed-loop control of the deceleration a while ensuring the effective tracking of the resolver signal, so that the vehicle controller can respond to the changes of the resolver signal more quickly, quickly control the drive motor 120 and the suspension, thereby reducing the fluctuation of the deceleration a during the braking process of the electric vehicle 1 and improving the braking performance of the electric vehicle 1.

[0130] In some embodiments, if the electric vehicle 1 is a vehicle with two drive motors 120, after the vehicle controller determines the total compensation torque T for the drive motor 120 for driving the two front wheels and the drive motor 120 for driving the two rear wheels, it is also necessary to determine the torque compensation ratio between the two drive motors 120 under different driving conditions.

[0131] In one embodiment, when the electric vehicle 1 is going uphill, the load on the rear axle 150 increases due to the rearward shift of the center of gravity of the electric vehicle 1. At this time, reducing the deceleration a during braking may require increasing the compensation torque T output by the drive motor 120 corresponding to the rear wheel in the compensation torque T. On the contrary, when the electric vehicle 1 is going downhill, the center of gravity of the electric vehicle 1 moves forward, and the load on the front axle 140 increases. At this time, reducing the deceleration a during braking may require increasing the compensation torque T output by the drive motor 120 corresponding to the front wheel in the compensation torque T. In addition, during the turning process, the load on the outer wheel 130 of the electric vehicle 1 (such as the right wheel when turning left) increases, and the load on the inner wheel 130 decreases. If the deceleration a of the electric vehicle 1 during braking is to be reduced at this time, the torque compensation ratio of the drive motor 120 needs to be dynamically adjusted according to the load change of the wheel 130. For example, during a left turn, the torque compensation ratio of the right front wheel RF and the right rear wheel RR may increase to better control the driving posture of the electric vehicle 1.

[0132] In one embodiment, the load on the electric vehicle 1 is uneven. For example, if the front of the electric vehicle 1 is heavily loaded, the vertical load on the front axle 140 will increase, and the front axle 140 will be affected differently by factors such as ground friction during braking. The vehicle controller needs to increase the proportion of the compensating torque T output by the drive motor 120 corresponding to the front wheel; if the rear of the electric vehicle 1 is heavily loaded, the vertical load on the rear axle 150 will increase, and the vehicle controller needs to increase the proportion of the compensating torque T output by the drive motor 120 corresponding to the rear wheel.

[0133] In one embodiment, the preset ratio between the compensation torque T output by the drive motor 120 corresponding to the front wheel and the drive motor 120 corresponding to the rear wheel can be set arbitrarily, for example, evenly distributing the torque, or randomly distributing the torque, etc., and this solution does not limit this. In this way, the flexibility of motor control can be improved.

[0134] In some embodiments, the suspension system 200 of the electric vehicle 1 includes a front suspension 230 and a rear suspension 240, and the vehicle controller also needs to allocate the damping F increase values ​​of the front suspension 230 and the rear suspension 240 according to the load transfer of the electric vehicle 1. For example, if the front load of the electric vehicle 1 is large; or when the electric vehicle 1 is going downhill, the load on the front axle 140 increases due to the forward shift of the center of gravity of the electric vehicle 1, the vehicle controller increases the proportion of the damping F increase value of the front suspension 230 when controlling the suspension system 200 to increase the damping F. If the rear load of the electric vehicle 1 is large; or when the electric vehicle 1 is going uphill, the load on the rear axle 150 increases due to the backward shift of the center of gravity of the electric vehicle 1, the vehicle controller increases the proportion of the damping F increase value of the rear suspension 240 when controlling the suspension system 200 to increase the damping F. Since the damping F of the shock absorber 220 in the suspension is larger, the shock absorber 220 can suppress the vibration after the elastic element rebounds more quickly, thereby improving the effect of the suspension system 200 in suppressing the vibration of the body of the electric vehicle 1 during braking by reasonably allocating the increase value of the damping F of the front suspension 230 and the rear suspension 240.

[0135] In this embodiment, during the braking process of the electric vehicle 1, the deceleration a of the electric vehicle 1 during braking is reduced by controlling the drive motor 120 to output a compensating torque T in the same direction as the rotational speed n of the wheel 130 and controlling the suspension to increase the damping F, thereby reducing the jerking phenomenon of the electric vehicle 1 during braking due to the rapid rate of change of the vehicle speed v. At the same time, when the drive motor 120 outputs the compensating torque T to cause the electric vehicle 1 to transfer load, the increased damping F of the suspension can ensure the effect of suppressing the vibration of the body of the electric vehicle 1, thereby reducing the jerking phenomenon of the electric vehicle 1 during braking. In addition, the vehicle controller obtains the sensor signal by directly connecting to the sensor, which effectively reduces the signal transmission time, thereby reducing the control delay and the braking distance of the electric vehicle 1. At the same time, the vehicle controller uses the actual deceleration a of the electric vehicle 1 (i.e., the actual decrease rate of the rotation speed n of the drive motor 120) as a feedback signal to adjust the output torque of the drive motor 120 and the increase value of the damping F of the suspension in real time, thereby realizing closed-loop control of the deceleration a of the electric vehicle 1, reducing the fluctuation of the deceleration a during the braking process of the electric vehicle 1, and making the deceleration curve of the electric vehicle 1 during the braking process closer to the ideal comfortable braking curve, thereby further reducing the frustration phenomenon of the electric vehicle 1 during the braking process, thereby improving the braking performance of the electric vehicle 1 and enhancing the driving experience of the user.

[0136] like Figure 7 As shown, Figure 7 Another operating schematic diagram of the braking control process of the electric vehicle 1 provided in an embodiment of the present application.

[0137] At the first moment t1, the user steps on the brake pedal and the electric vehicle 1 enters the braking process. The brake controller 310 controls the braking device 320 to brake the four wheels 130 of the electric vehicle 1. The vehicle speed v of the electric vehicle 1 (the rotation speed n of the drive motor 120) decreases under the action of the braking force output by the braking system 300. The rotation speed n of the drive motor 120 decreases as the vehicle speed v of the electric vehicle 1 decreases. The deceleration a of the electric vehicle 1 during the braking process increases as the braking force increases.

[0138] At the second moment t2 after the first moment t1, during the process of the braking device 320 braking the four wheels 130 of the electric vehicle 1, the vehicle controller can receive the rotational transformer signal and the acceleration signal sent by the sensor, and the vehicle controller detects that the deceleration a of the electric vehicle 1 at the second moment t2 is less than the preset deceleration a1 and the speed v of the electric vehicle 1 is less than the preset speed v1 according to the rotational transformer signal and the acceleration signal, then it is determined that the electric vehicle 1 enters the final stage of braking in the non-emergency braking state at the second moment t2.

[0139] At the second moment t2, the vehicle controller uses the comfort braking curve corresponding to the electric vehicle 1 as a reference curve, and the deceleration difference a2 between the deceleration a of the electric vehicle 1 and the ideal deceleration under the comfort braking curve controls the drive motor 120 to output the compensation torque T and controls the suspension to increase the damping F. The vehicle controller controls the magnitude of the compensation torque T output by the drive motor 120 to increase with the increase of the deceleration difference a2, and the vehicle controller controls the increase value of the damping F of the suspension to increase with the increase of the deceleration difference a2.

[0140] Since the operating conditions and external environment of the electric vehicle 1 are constantly changing, at the third moment t3 after the second moment t2, if the vehicle controller detects that the rate of reduction of the rotational speed n of the drive motor 120 (the deceleration a of the electric vehicle 1 increases) according to the received rotational transformation signal while controlling the drive motor 120 to continuously output the compensation torque T, in order to ensure that the electric vehicle 1 can stably maintain the ideal deceleration under the comfort braking curve, the vehicle controller controls the compensation torque T output by the drive motor 120 to increase, and controls the suspension to increase the damping F, that is, the vehicle controller controls the damping F of the suspension at the third moment t3 to be greater than the damping F of the suspension at the second moment t2.

[0141] In this embodiment, when the electric vehicle 1 enters an uphill section, the decreasing rate of the rotation speed n of the drive motor 120 increases (the deceleration a of the electric vehicle 1 increases); when the electric vehicle 1 enters a bumpy section, the decreasing rate of the rotation speed n of the drive motor 120 fluctuates (the deceleration a of the electric vehicle 1 fluctuates), and at the third moment t3, the decreasing rate of the rotation speed n of the drive motor 120 shows an increasing trend. At the third moment t3, the vehicle controller controls the increase value of the compensation torque T of the drive motor 120 to increase with the increase of the decreasing rate of the rotation speed n of the drive motor 120, and controls the increase value of the damping F of the suspension to increase with the increase of the decreasing rate of the rotation speed n of the drive motor 120.

[0142] In this embodiment, during the braking process of the electric vehicle 1, the deceleration a of the electric vehicle 1 during the braking process is reduced by controlling the drive motor 120 to output the compensation torque T in the same direction as the rotation speed n of the wheel 130 and controlling the suspension to increase the damping F, thereby reducing the frustration of the electric vehicle 1 during the braking process due to the rapid change rate of the vehicle speed v. At the same time, when the drive motor 120 outputs the compensation torque T so that the electric vehicle 1 undergoes load transfer, the suspension increases the damping F to ensure the vibration suppression effect on the body of the electric vehicle 1, thereby reducing the frustration of the electric vehicle 1 during the braking process. In addition, the vehicle controller uses the actual deceleration a of the electric vehicle 1 (i.e., the actual decrease rate of the rotation speed n of the drive motor 120) as a feedback signal to adjust the output torque of the drive motor 120 and the increase value of the damping F of the suspension in real time, thereby realizing closed-loop control of the deceleration a of the electric vehicle 1, reducing the fluctuation of the deceleration a during the braking process of the electric vehicle 1, thereby further reducing the frustration of the electric vehicle 1 during the braking process, thereby improving the braking performance of the electric vehicle 1 and enhancing the driving experience of the user.

[0143] See also Figure 8 , Figure 8 A schematic diagram of the operation of the electric vehicle 1 in the emergency braking mode provided in an embodiment of the present application.

[0144] At the first moment t1, the user steps on the brake pedal and the electric vehicle 1 enters the braking process. The brake controller 310 controls the braking device 320 to brake the four wheels 130 of the electric vehicle 1. The speed v of the electric vehicle 1 decreases under the action of the braking force output by the braking system 300. The rotation speed n of the drive motor 120 decreases as the speed v of the electric vehicle 1 decreases. The deceleration a of the electric vehicle 1 during the braking process increases as the braking force increases.

[0145] like Figures 6 to 8 As shown, at the first time t1 , the electric vehicle 1 starts braking at the same vehicle speed. Figure 6 as well as Figure 7 After the first moment t1, the deceleration a of the electric vehicle 1 during braking is less than the preset deceleration a1, and the electric vehicle 1 is in a non-emergency braking mode; Figure 8 After the first moment t1, the deceleration a of the electric vehicle 1 during the braking process is greater than or equal to the preset deceleration a1, and the electric vehicle 1 is in the emergency braking mode.

[0146] like Figure 6 as well as Figure 7As shown, at the second moment t2, in response to the deceleration a of the electric vehicle 1 during braking being less than the preset deceleration a1 and the vehicle speed of the electric vehicle being less than the preset vehicle speed v1, the electric vehicle 1 is in the final stage of braking in the non-emergency braking mode, and the drive motor 120 is controlled to output the compensation torque T and the suspension is controlled to increase the damping F.

[0147] like Figure 8 As shown, in one embodiment, at the second moment t2, in response to the deceleration a of the electric vehicle 1 during braking being greater than or equal to the preset deceleration a1, the electric vehicle 1 is in emergency braking mode, and the compensation torque T output by the drive motor 120 is controlled to be zero.

[0148] In one embodiment, at the second moment t2, in response to the pedal stroke of the brake pedal being greater than or equal to a preset stroke, the electric vehicle 1 is in an emergency braking mode, and the compensation torque T output by the drive motor 120 is controlled to be zero.

[0149] In one embodiment, at the second moment t2, in response to the reduction rate of the rotation speed n of the drive motor 120 being greater than or equal to a preset reduction rate, the electric vehicle 1 is in an emergency braking mode, and the compensation torque T output by the drive motor 120 is controlled to be zero.

[0150] Specifically, during the braking process of the electric vehicle 1, the vehicle controller is used to receive a braking signal from the brake controller 310. During the braking process, the deceleration a of the electric vehicle 1 is greater than or equal to the preset deceleration a1; or, the pedal stroke of the brake pedal is greater than the preset stroke; or, the reduction rate of the rotation speed n of the drive motor 120 is greater than or equal to the preset reduction rate, indicating that the braking mode of the electric vehicle 1 is the emergency braking mode at this time.

[0151] When the electric vehicle 1 is in the emergency braking mode, in order to ensure the braking efficiency and braking safety of the electric vehicle 1, the vehicle controller controls the compensation torque T output by the drive motor 120 to be zero, so that the braking force of the electric vehicle 1 during the braking process always maintains the braking value indicated by the braking controller 310, that is, in the emergency braking mode, the braking scheme provided in the present application to reduce the jerking phenomenon of the electric vehicle 1 at the end of braking will not take effect.

[0152] It should be understood that Figures 6 to 8 The numerical changes in are only for illustration and do not represent specific values, and there may be certain deviations. The change trend is only used to illustrate the method flow of the present application scheme, and does not limit the deviation in the actual control process.

[0153] In this embodiment, during the braking process of the electric vehicle 1, when the deceleration a of the electric vehicle 1 is greater than or equal to the preset deceleration a1, it indicates that the braking mode of the electric vehicle 1 is emergency braking at this time. Since the emergency braking mode requires that the electric vehicle 1 stop moving within the shortest possible distance to avoid dangerous situations such as collision and loss of control of the electric vehicle 1, the braking efficiency and braking safety of the electric vehicle 1 need to be ensured when the braking mode of the electric vehicle 1 is emergency braking. Therefore, at this time, the vehicle controller will not control the drive motor 120 to output the compensation torque T, thereby ensuring the braking efficiency and braking safety of the electric vehicle 1.

[0154] In the embodiments provided in the present application, each functional module may be integrated into one device, or each module may exist physically separately, or two or more modules may be integrated into one device.

[0155] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A control method for electric vehicle non-sensing braking, characterized in that: The control method is used to control the driving motor and suspension of the electric vehicle during the braking process of the electric vehicle to reduce the setback of the electric vehicle during the braking process, and the control method includes: At a first moment, controlling a braking device of the electric vehicle to brake the electric vehicle; At a second moment after the first moment, during the process of the braking device braking the electric vehicle, controlling the drive motor to output a compensation torque and controlling the suspension to increase damping; The direction of the compensation torque is the same as the rotational speed direction of the wheels of the electric vehicle.

2. The control method according to claim 1, characterized in that: At the second moment, the deceleration of the electric vehicle is less than a preset deceleration and the vehicle speed of the electric vehicle is less than a preset vehicle speed.

3. The control method according to claim 1, characterized in that: At the second moment, the speed reduction rate of the driving motor is less than a preset speed reduction rate and the speed of the driving motor is less than a preset speed.

4. The control method according to any one of claims 1 to 3, characterized in that: The control method further comprises: At a third time after the second time, in response to a decrease in the rate of decrease in the rotation speed of the drive motor, the drive motor is controlled to reduce the compensation torque and the suspension is controlled to increase damping.

5. The control method according to claim 4, characterized in that: The control method specifically includes: At the third moment, the compensation torque reduction value of the drive motor is controlled to increase as the speed reduction rate of the drive motor decreases, and the damping increase value of the suspension is controlled to increase as the speed reduction rate of the drive motor decreases.

6. The control method according to any one of claims 1 to 3, characterized in that: The control method further comprises: At a third time after the second time, in response to an increase in the rate of decrease in the rotation speed of the drive motor, the drive motor is controlled to increase the compensation torque and the suspension is controlled to increase damping.

7. The control method according to claim 4, characterized in that: The control method specifically includes: At the third moment, the compensation torque increase value of the drive motor is controlled to increase with the increase of the speed reduction rate of the drive motor, and the damping increase value of the suspension is controlled to increase with the increase of the speed reduction rate of the drive motor.

8. The control method according to any one of claims 1 to 3, characterized in that: The control method specifically includes: Controlling the compensation torque output by the drive motor to increase as the pedal stroke of the brake pedal of the electric vehicle increases; The damping increase value of the suspension is controlled to increase as the pedal stroke of the brake pedal of the electric vehicle increases.

9. The control method according to any one of claims 1 to 3, characterized in that: The control method specifically includes: At the second moment, during the braking process of the electric vehicle decelerating at a first deceleration, controlling the drive motor to output a first compensation torque and controlling the suspension to increase a first damping; At the second moment, during the braking process of the electric vehicle decelerating at a second deceleration, controlling the drive motor to output a second compensation torque and controlling the suspension to increase a second damping; The first deceleration is smaller than the second deceleration, the first compensation torque is smaller than the second compensation torque, and the first damping is smaller than the second damping.

10. The control method according to any one of claims 1 to 9, characterized in that: The control method further comprises: During the process of braking the electric vehicle by the braking device, in response to the deceleration of the electric vehicle being greater than or equal to a preset deceleration, the compensation torque output by the drive motor is controlled to be zero and the damping increase value of the suspension is controlled to be zero.

11. A vehicle controller for sensorless braking control of electric vehicles, characterized in that: The vehicle controller is used to control the output torque of the driving motor of the electric vehicle to drive the four wheels of the electric vehicle and control the suspension output damping of the electric vehicle to reduce the setback of the electric vehicle. The vehicle controller is specifically used to: During the braking process of the electric vehicle, in response to the deceleration of the electric vehicle being less than a preset deceleration and the vehicle speed of the electric vehicle being less than a preset vehicle speed, controlling the drive motor to output a compensation torque and controlling the suspension to increase damping; The direction of the compensation torque is the same as the rotational speed direction of the wheels of the electric vehicle.

12. The vehicle controller according to claim 11, characterized in that: The vehicle controller is specifically used for: During the electric vehicle braking process, in response to a decrease in the rate of decrease in the rotation speed of the drive motor, the drive motor is controlled to increase the compensation torque and the suspension is controlled to increase damping.

13. The vehicle controller according to claim 11, characterized in that: The vehicle controller is specifically used for: During the electric vehicle braking process, in response to a decrease in the rate of decrease in the rotation speed of the drive motor, the drive motor is controlled to increase the compensation torque and the suspension is controlled to increase damping.

14. An electric vehicle, characterized in that: The electric vehicle comprises a drive motor, a suspension and a vehicle controller as claimed in any one of claims 11 to 13, wherein the vehicle controller is used to control the drive motor and the suspension to execute the control method as claimed in any one of claims 1 to 10.

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