Control method of electric vehicle, motor controller and electric vehicle

Abstract

The invention provides a control method of an electric vehicle, a motor controller and the electric vehicle, and is applied to the technical field of electric vehicles, and the control method is used for controlling a driving system of the electric vehicle after a racing track mode of the electric vehicle is started so as to improve the driving controllability of the electric vehicle in a racing track. Comprising the steps that at a first moment, the opening degree of an accelerator pedal of the electric vehicle is a first accelerator pedal opening degree, the slip rate of the electric vehicle is smaller than a preset slip rate, and a driving motor is controlled to output a first torque indicated by the first accelerator pedal opening degree; at the second moment after the first moment, the opening degree of an accelerator pedal of the electric vehicle is the first accelerator pedal opening degree, the slip rate of the electric vehicle is larger than or equal to the preset slip rate, and the torque output by the driving motor is actively controlled to be reduced to be smaller than the first torque. Therefore, the torque output of the driving motor is controlled by responding to the slip rate change of the vehicle in time, the operation stability of the electric vehicle is improved, and the driving safety is ensured.

Description

Technical Field

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

[0002] During extreme driving of electric vehicles such as racing, users will operate the electric vehicles to increase the vehicle's speed and acceleration. Once the electric vehicle's ability to resist interference and maintain stable driving under the aforementioned user operation (which can be called the electric vehicle's handling stability) is low, it will be difficult for the user to accurately control the vehicle, and the electric vehicle will find it difficult to achieve the user's expected driving state. The electric vehicle is also prone to losing control, affecting driving safety. Summary of the invention

[0003] The embodiments of the present application provide a control method for an electric vehicle, a motor controller, and an electric vehicle, which actively control the drive motor to reduce the torque output in response to the increase in slip rate in a timely manner after the track mode of the electric vehicle is started, thereby avoiding the electric vehicle from slipping, improving the handling stability of the electric vehicle during extreme driving processes such as track driving, and ensuring driving safety.

[0004] In a first aspect, an embodiment of the present application provides a control method for an electric vehicle, the control method being used to control a drive system of the electric vehicle after a track mode of the electric vehicle is started to improve the maneuverability of the electric vehicle when driving on a track, the control method comprising: at a first moment, an opening of an accelerator pedal of the electric vehicle is a first accelerator pedal opening and a slip rate of the electric vehicle is less than a preset slip rate, and the drive motor is controlled to output a first torque indicated by the first accelerator pedal opening; at a second moment after the first moment, an opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and a slip rate of the electric vehicle is greater than or equal to a preset slip rate, and the torque output by the drive motor is actively controlled to be reduced to less than the first torque.

[0005] When the electric vehicle is driving on a track, the user can operate the accelerator pedal to accelerate the electric vehicle. By setting the opening of the accelerator pedal at the second moment to be the same as that at the first moment, both are the first accelerator pedal opening, it is described that in this scenario, the slip rate of the electric vehicle increases to greater than or equal to the preset slip rate at the second moment, which is not due to the increase in the opening of the accelerator pedal.

[0006] In this embodiment, the electric vehicle is automatically controlled by providing a track mode for the electric vehicle to improve the handling stability of the electric vehicle during the track driving process. Specifically, during the driving process after the electric vehicle starts the track mode (the electric vehicle will accelerate during the process), by automatically controlling the drive motor of the electric vehicle to reduce the torque output when the slip rate of the electric vehicle is greater than or equal to the preset slip rate, the slip rate of the electric vehicle can be reduced to less than the preset slip rate, and the torque output of the drive motor is automatically controlled during the track driving process of the electric vehicle to avoid the electric vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and reducing the user's operating burden. Even drivers with insufficient driving experience can have a good racing experience. In addition, during the track driving process of the electric vehicle, the drive motor is actively controlled to reduce the torque output, rather than responding to the torque signal issued by the vehicle body electronic stability system through the vehicle controller to control the drive motor to reduce the torque output, thereby timely responding to the change in the vehicle slip rate to control the torque output of the drive motor, reducing the control delay of the electric vehicle, further improving the handling stability of the electric vehicle, and ensuring driving safety.

[0007] In an embodiment of the first aspect, the control method also includes: at a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is a second accelerator pedal opening greater than the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to a preset slip rate, and the drive motor is actively controlled to adjust the output torque to be less than a second torque indicated by the second accelerator pedal opening.

[0008] In this embodiment, the opening of the accelerator pedal at the second moment is set to be greater than the opening of the accelerator pedal at the first moment, so as to describe that the slip rate of the electric vehicle in this scenario increases to be greater than or equal to the preset slip rate at the second moment because the opening of the accelerator pedal increases. When the electric vehicle is driving on the track, in the case where the slip rate of the electric vehicle is greater than or equal to the preset slip rate due to the increase in the opening of the accelerator pedal operated by the user, the drive motor of the electric vehicle is automatically controlled to reduce the torque output to reduce the slip rate of the electric vehicle to less than the preset slip rate without responding to the opening of the accelerator pedal operated by the user, so that the torque output of the drive motor is automatically controlled to avoid the electric vehicle from slipping out of control during the electric vehicle driving on the track, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0009] In an embodiment of the first aspect, the control method further includes: during driving after the track mode of the electric vehicle is started, controlling a body electronic stability system of the electric vehicle to be turned off.

[0010] In this embodiment, when the electric vehicle is driving on a track, the body electronic stability system of the electric vehicle is controlled to be turned off, so that in this application, the drive motor reduces the torque output not in response to the instruction of the torque signal sent by the body electronic stability system through the vehicle controller, but actively controls the drive motor to reduce the torque output, thereby achieving timely response to changes in the vehicle slip rate to control the torque output of the drive motor, improving the handling stability of the electric vehicle and ensuring driving safety.

[0011] In an embodiment of the first aspect, the control method further includes: during driving after the track mode of the electric vehicle is activated, displaying a preset acceleration on the dashboard or central control screen of the electric vehicle, wherein the preset acceleration is used to indicate the maximum acceleration allowed at the current track position of the electric vehicle.

[0012] In this embodiment, when the electric vehicle is driving on a track, a preset acceleration is displayed on the instrument panel or central control screen of the electric vehicle, so that the user can obtain the maximum acceleration allowed by the electric vehicle for the current track position, which is beneficial to improving the user's driving experience and confidence, so as to facilitate the subsequent control of the electric vehicle according to the preset acceleration, thereby improving the driving experience.

[0013] In an embodiment of the first aspect, the control method further includes: controlling a preset acceleration displayed on the instrument panel or the central control screen to decrease as the adhesion coefficient of the track position decreases.

[0014] In this embodiment, when the electric vehicle is driving on a track, the preset acceleration displayed on the instrument panel or the central control screen is controlled to decrease as the adhesion coefficient of the track position decreases, thereby realizing the preset acceleration displayed on the instrument panel or the central control screen flexibly according to the decrease of the adhesion coefficient at the track position, so that the user can obtain the maximum acceleration allowed by the electric vehicle for the current track position under different adhesion coefficients, which is beneficial to improving the user's driving experience and confidence.

[0015] In an embodiment of the first aspect, the control method further includes: the greater the decrease in the adhesion coefficient, the greater the decrease rate of the preset acceleration displayed on the instrument panel or central control screen of the electric vehicle.

[0016] In this embodiment, when the electric vehicle is driving on a track, the greater the reduction in the adhesion coefficient, the greater the reduction rate of the preset acceleration displayed on the instrument panel or central control screen of the electric vehicle. This ensures that the preset acceleration can be quickly displayed on the instrument panel or central control screen when the adhesion coefficient is reduced at different track positions. This enables the user to obtain the maximum acceleration allowed by the electric vehicle for the current track position under different adhesion coefficients, which is beneficial to improving the user's driving experience and confidence.

[0017] In an embodiment of the first aspect, the control method further includes: during driving after the track mode of the electric vehicle is started, actively controlling the drive motor to reduce the torque output so that the acceleration of the electric vehicle is less than a preset acceleration displayed on the instrument panel or the central control screen.

[0018] In this embodiment, when the electric vehicle is driving on a track, the user can obtain the value of a preset acceleration. When the acceleration of the electric vehicle is greater than the preset acceleration, the electric vehicle will slip and lose control. By actively controlling the drive motor to reduce the torque output so that the acceleration of the electric vehicle is less than the preset acceleration displayed on the instrument panel or the central control screen, the torque output of the drive motor is automatically controlled when the electric vehicle is in track mode to avoid the electric vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0019] In an embodiment of the first aspect, the control method further includes: at a first moment, controlling the drive motor to output a torque indicated by a torque signal; and at a second moment, actively controlling the drive motor to output a torque that is less than the torque indicated by the torque signal.

[0020] In this embodiment, when the electric vehicle is driving on a track, when the slip rate is greater than or equal to the preset slip rate, the torque output by the drive motor is actively controlled to be less than the torque indicated by the torque signal, rather than responding to the torque signal issued by the electronic stability program through the vehicle controller to control the drive motor to adjust the torque output. This achieves timely response to the vehicle's slip rate changes to control the torque output of the drive motor, improves the handling stability of the electric vehicle, and ensures driving safety.

[0021] In an embodiment of the first aspect, the control method further includes: at the second moment, the greater the slip rate of the electric vehicle, the greater the reduction in torque output by the actively controlled drive motor.

[0022] In this embodiment, when the electric vehicle is driving on a track, by automatically controlling the reduction in torque output by the drive motor when the slip rate of the electric vehicle is greater than or equal to a preset slip rate and the greater the slip rate, the greater the reduction in torque output by the drive motor can be flexibly controlled according to the slip rate of the electric vehicle, thereby achieving automatic control of the torque output of the drive motor under different slip rates to prevent the electric vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0023] In an embodiment of the first aspect, the control method also includes: at a second moment t2, the slip rate of the electric vehicle is a first slip rate, and the drive motor is actively controlled to output a third torque; at the second moment, the slip rate of the electric vehicle is a second slip rate, and the drive motor is actively controlled to output a fourth torque; the first slip rate is greater than the second slip rate, and the third torque is less than the fourth torque.

[0024] In this embodiment, when the electric vehicle is driving on a track, when the slip rate of the electric vehicle is greater than or equal to a preset slip rate and the slip rate is large, the torque output by the drive motor is automatically controlled to be smaller; when the slip rate of the electric vehicle is greater than or equal to a preset slip rate and the slip rate is small, the torque output by the drive motor is automatically controlled to be larger. This achieves automatic control of the torque output of the drive motor to prevent the electric vehicle from slipping and losing control, improves the handling stability of the electric vehicle, and ensures driving safety.

[0025] In an embodiment of the first aspect, the control method further includes: during driving of the electric vehicle after the track mode is activated, calculating the slip rate of the electric vehicle according to the motor speed indicated by the resolver sensor of the drive motor.

[0026] In this embodiment, the resolver signal is a signal that can be directly obtained by the motor controller. The resolver signal indicates the motor speed. Compared with the wheel speed signal, the resolver signal has higher accuracy and better stability. The slip rate can be calculated quickly and accurately based on the resolver signal.

[0027] In an embodiment of the first aspect, the control method also includes: during driving after the track mode of the electric vehicle is started, an acceleration indicator is displayed on the dashboard or central control screen of the electric vehicle; the acceleration indicator includes two display states for indicating that the slip rate of the electric vehicle is less than a preset slip rate and that the slip rate of the electric vehicle is greater than or equal to the preset slip rate.

[0028] In this embodiment, when the electric vehicle is driving on a track, the user can accurately obtain whether the electric vehicle is slipping and whether the acceleration of the electric vehicle is greater than or equal to the preset acceleration through the display status of the acceleration indicator. The user can take corresponding measures for the slipping or sliding wheels based on this information, thereby improving driving safety, while also helping to improve the user's driving experience and confidence.

[0029] In an embodiment of the first aspect, the control method further includes: during driving after the track mode of the electric vehicle is started, obtaining torque data output by the drive motor during driving on the track and storing it in a target storage space; during driving after the electric vehicle starts the track mode next time, obtaining torque data from the target storage space, and controlling the torque output of the drive motor according to the torque data.

[0030] In this embodiment, when the electric vehicle is driving on the track, by acquiring the torque data output by the drive motor during the driving process on the track and storing it in the target storage space, it is beneficial to analyze whether the acceleration of the electric vehicle is close to the preset acceleration at each track position, so as to provide users with a better racing experience. At the same time, when the electric vehicle is driving after starting the track mode next time, the torque data is acquired from the target storage space, and the torque output of the drive motor is controlled according to the torque data, which can reduce the automatic control cost while improving the stability of the electric vehicle and ensuring driving safety.

[0031] In an embodiment of the first aspect, the control method also includes: at a third moment after the first moment, the accelerator pedal opening is reduced to zero, the brake pedal opening is the first brake pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, and the braking system of the electric vehicle is controlled to output braking force; at a fourth moment after the third moment, the brake pedal opening is the first brake pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the braking system of the electric vehicle is actively controlled to reduce the braking force output.

[0032] When an electric vehicle is driving on a track, the lateral force that the wheels need to bear increases when the electric vehicle enters a curve. The wheels will find it difficult to bear such a huge lateral force, resulting in a decrease in grip and causing the electric vehicle to lose control. Therefore, before the electric vehicle enters a curve, the user can operate the brake pedal to brake the electric vehicle.

[0033] By setting the opening of the brake pedal at the fourth moment to be the same as that at the third moment, that is, the first brake pedal opening, it is described that in this scenario, the slip rate of the electric vehicle increases to be greater than or equal to the preset slip rate at the fourth moment and this is not due to the increase in the opening of the brake pedal.

[0034] In this embodiment, when the electric vehicle is running on the track, in response to the brake pedal opening being greater than zero, the brake system is controlled to output braking force to brake the electric vehicle. In this process, when the slip rate of the electric vehicle is greater than or equal to the preset slip rate, the brake system of the electric vehicle is automatically controlled to reduce the braking force output so that the slip rate of the electric vehicle is reduced to less than the preset slip rate, so that when the electric vehicle is decelerating on the track, the torque output of the drive motor is automatically controlled to prevent the electric vehicle from slipping out of control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0035] In an embodiment of the first aspect, the control method further includes: at the fourth moment, the greater the slip rate of the electric vehicle, the greater the reduction in the braking force output by the active control braking system.

[0036] In this embodiment, when the electric vehicle is driving on a track, the reduction in the braking force output by the braking system is automatically controlled to be greater than or equal to a preset slip rate and the greater the slip rate, the greater the reduction. The reduction in the braking force output by the braking system can be flexibly controlled according to the slip rate of the electric vehicle, thereby achieving automatic control of the braking force output by the braking system under different slip rates to prevent the electric vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0037] In a second aspect, an embodiment of the present application provides a motor controller, which is used to control the drive system of the electric vehicle after the track mode of the electric vehicle is started to improve the handling stability of the electric vehicle when driving on the track. The motor controller is specifically used to: at a first moment, the opening of the accelerator pedal of the electric vehicle is a first accelerator pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, control the drive motor to output a first torque indicated by the first accelerator pedal opening; at a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, actively control the torque output by the drive motor to be reduced to less than the first torque.

[0038] In this embodiment, when the electric vehicle is driving on a track, when the slip rate is greater than or equal to a preset slip rate, the motor controller directly controls the drive motor to reduce the torque output, rather than responding to the instruction of the torque signal sent by the electronic stability program through the vehicle controller to control the drive motor to reduce the torque output. This decouples the operation of the motor controller and the drive motor from the vehicle controller, so that after the slip rate increases, the motor controller can actively control the drive motor of the electric vehicle to reduce the torque output and promptly avoid the vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0039] The motor controller is also used to execute the control method of the electric vehicle in other embodiments of the first aspect.

[0040] In a third aspect, an embodiment of the present application provides an electric vehicle, the electric vehicle comprising four drive motors and a motor controller, wherein:

[0041] At a first moment, the opening of the accelerator pedal of the electric vehicle is a first accelerator pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, and the motor controller is used to control the drive motor to output a first torque indicated by the first accelerator pedal opening;

[0042] At a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the motor controller is used to actively control the torque output by the drive motor to be reduced to less than the first torque.

[0043] As for the supplementary and technical effects of the solutions provided in the second and third aspects above, please refer to the corresponding description of the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of an electric vehicle 100 provided in an embodiment of the present application is shown;

[0045] Figure 2 A schematic diagram showing the architecture of an electric vehicle 100 provided in an embodiment of the present application is shown;

[0046] Figure 3 A schematic diagram showing a driving scene of an electric vehicle 100 provided in an embodiment of the present application is shown;

[0047] Figure 4 A schematic diagram showing a control method for an electric vehicle 100 provided in an embodiment of the present application is shown;

[0048] Figure 5 A schematic diagram of a friction circle of an electric vehicle 100 provided in an embodiment of the present application is shown;

[0049] Figure 6 A schematic diagram showing the acceleration of an electric vehicle 100 provided in an embodiment of the present application;

[0050] Figure 7 A schematic diagram showing a control method for an electric vehicle 100 provided in an embodiment of the present application is shown;

[0051] Figure 8 A schematic diagram of a central control screen of an electric vehicle 100 provided in an embodiment of the present application is shown;

[0052] Fig. 9 A schematic diagram of a central control screen of an electric vehicle 100 provided in an embodiment of the present application is shown;

[0053] Fig.10 A schematic diagram of a central control screen of an electric vehicle 100 provided in an embodiment of the present application is shown;

[0054] Fig.11 A schematic diagram showing a control method for an electric vehicle 100 provided in an embodiment of the present application is shown;

[0055] Fig.12 A schematic diagram of a motor controller of an electric vehicle 100 provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0057] The prefixes such as "first" and "second" used in the embodiments of the present application are only used to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers used to distinguish description objects in the embodiments of the present application does not constitute a limitation on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and the use of such prefixes should not constitute an unnecessary limitation.

[0058] During extreme driving of electric vehicles such as racing, users will operate the electric vehicles to increase the vehicle's speed and acceleration. Once the electric vehicle's ability to resist interference and maintain stable driving under the aforementioned user operation (which can be called the electric vehicle's handling stability) is low, it will be difficult for the user to accurately control the vehicle, and the electric vehicle will find it difficult to achieve the user's expected driving state. The electric vehicle is also prone to losing control, affecting driving safety.

[0059] Most electric vehicles are now pre-installed with an Electronic Stability Program (ESP), which can improve the handling stability of electric vehicles during driving. However, the maximum acceleration of electric vehicles allowed by the ESP is relatively small, and it is difficult for electric vehicles to achieve the user's expected driving state, and it is impossible to provide users with a good racing experience. In one embodiment, for electric vehicles that provide a track mode, the degree of intervention of the ESP can be adjusted by providing a switch or an intervention gear adjustment button for the ESP, so as to return more control of the electric vehicle to the driver.

[0060] However, this method requires a high threshold of driving skills from the user, is difficult to use, and requires the user to intervene in the electronic stability system of the vehicle body for each track. The operation is complicated and the accuracy is low. At the same time, the control of the electronic stability system of the vehicle body requires the torque signal to be sent to the motor controller through the vehicle controller, and then the motor controller controls the drive motor. The entire control link has a long delay and low bandwidth, and it is difficult to respond in time to control the torque output of the drive motor. When driving fiercely on the track, the vehicle is prone to instability, affecting driving safety.

[0061] In view of this, the embodiments of the present application provide a control method for an electric vehicle, a motor controller and an electric vehicle, which actively control the drive motor to reduce the torque output by promptly responding to the increase in slip rate after the track mode of the electric vehicle is started, thereby preventing the electric vehicle from slipping and losing control, improving the handling stability of the electric vehicle during extreme driving processes such as track driving, and ensuring driving safety.

[0062] The control method, motor controller, and electric vehicle provided in the embodiments of the present application can be applied to control the electric vehicle when the electric vehicle is driving on a track or other environments similar to the driving state of the track. The embodiments of the present application are mainly introduced by taking the driving of the electric vehicle on a track as an example, and the track can be replaced with other driving environments. The track does not impose any restrictions on the control method, motor controller, and electric vehicle provided in the embodiments of the present application.

[0063] See also Figure 1 , Figure 1 FIG. 1 shows a schematic diagram of an electric vehicle 100 provided in an embodiment of the present application. Figure 1 As shown, the electric vehicle 100 includes a drive system 110, a power battery 120 connected to the drive system 110, and a vehicle controller 130. The drive system 110 is used to drive the electric vehicle 100. The power battery 120 is used to provide electrical energy to the drive system 110. The drive system 110 is used to receive power from the power battery 120 and provide power to the electric vehicle 100. The drive system 110 can also be called a powertrain.

[0064] Optionally, the electric vehicle 100 further includes a braking system 140 , which is used to provide braking force for the electric vehicle 100 when the electric vehicle 100 is in a braking state.

[0065] According to the position of the wheels in the electric vehicle 100, they can be divided into a left front wheel FL, a right front wheel FR, a left rear wheel BL, and a right rear wheel BR. According to the axle, the left front wheel and the right front wheel are coaxial and connected by the front axle. The left rear wheel and the right rear wheel are coaxial and connected by the rear axle. According to the position, the left front wheel and the left rear wheel are on the same side and located on the left side, and the right front wheel and the right rear wheel are on the same side and located on the right side. That is to say, among the four wheels of the electric vehicle 100, the left front wheel and the right front wheel are coaxial wheels with each other, and the left rear wheel and the right rear wheel are coaxial wheels with each other; the left front wheel and the left rear wheel are wheels on the same side, and the right front wheel and the right rear wheel are wheels on the same side.

[0066] The electric vehicle 100 in the embodiment of the present application can be any one of different types of vehicles such as a sedan, 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 in the embodiment of the present application. Among them, the vehicle includes but is not limited to a pure electric vehicle (pure electric vehicle / battery electric vehicle, pure EV / batteryEV), a hybrid electric vehicle (hybrid electric vehicle, HEV), a range extended electric vehicle (range extended electric vehicle, REEV), a plug-in hybrid electric vehicle (plug-in hybrid electric vehicle, PHEV), a new energy vehicle (new energy vehicle, NEV), etc.

[0067] The embodiment of the present application does not limit the specific type of the powertrain. As an example and not a limitation, the powertrain can be a centralized powertrain, a hub motor powertrain, or a wheel-side motor powertrain. Among them, the hub motor powertrain is to directly set the motor and the reducer in the wheel rim, eliminating the transmission components such as the half shaft, universal joint, differential, and transmission; the wheel-side motor powertrain is to set the motor on the subframe.

[0068] The power battery 120 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 in the present application. In terms of scale, the power battery 120 in the embodiment of the present application can be a single cell, or a battery module or a battery pack, which is not limited in the present application. The power battery 120 can also power other electrical devices in the vehicle, such as the air conditioner in the vehicle, the car player, etc.

[0069] Figure 2 A schematic diagram of the architecture of an electric vehicle 100 provided in an embodiment of the present application is shown.

[0070] See also Figure 2 (a) The electric vehicle 100 is a two-wheel drive vehicle, and the driving system 110 includes a driving motor 111 for two front wheels and a motor controller 121 for the driving motor 111 , and a driving motor 112 for two rear wheels and a motor controller 122 for the driving motor 112 .

[0071] Each drive motor in the drive system 110 is used to provide driving force for the electric vehicle 100. Specifically, when the electric vehicle 100 is in a driving state, the motor controller of each drive motor receives a torque signal, receives electric energy from the power battery 120, and controls the corresponding drive motor to output the torque indicated by the torque signal.

[0072] When the electric vehicle 100 is in a driving state, each drive motor in the drive system 110 is used to provide driving force for the electric vehicle 100. Specifically, when the electric vehicle 100 is in a driving state, the vehicle controller 130 calculates the torque demand of the electric vehicle and outputs a torque signal to the motor controller of each drive motor. Each motor controller receives a torque signal from the power battery 120 (such as Figure 1 The electric energy (as shown) is used to control the corresponding drive motor to output the torque indicated by the torque signal.

[0073] Continue to refer Figure 2 (a) in the figure, the braking system 140 mainly includes a brake pedal ( Figure 2 (a) (not shown), a brake controller 141 and four wheel-end brake devices 142. The brake controller 141 can generate a brake signal based on the opening of the brake pedal, and control one or more of the four wheel-end brake devices 142 to output a braking force to the corresponding wheel based on the indication of the brake signal to prevent the wheel from rotating or the tendency of the wheel to rotate.

[0074] During the braking process of the electric vehicle 100 , the greater the braking force indicated by the braking signal, the greater the braking force output by the wheel-end braking device 142 , and the faster the speed of the electric vehicle 100 decreases.

[0075] When the electric vehicle 100 is in a braking state, the drive system 110 stops driving the wheels to rotate, and the brake system 140 provides braking force to the wheels so that the electric vehicle 100 reduces its speed under the action of the braking force. In the braking state of the electric vehicle 100, each drive motor in the electric vehicle 100 with an energy recovery function can also be used to provide braking force for the electric vehicle 100. Specifically, when the electric vehicle 100 is in a braking state, the vehicle controller 130 receives a braking signal and sends an energy recovery instruction to each motor controller. Each motor controller controls the corresponding drive motor to operate in a power generation state in response to the energy recovery instruction. Each drive motor converts the kinetic energy of the wheels of the electric vehicle into electrical energy and outputs a reverse torque to the wheels of the electric vehicle 100 to provide braking force to the electric vehicle 100.

[0076] The brake in the braking system 140 in the embodiment of the present application may be an electronic hydraulic brake (EHB) or an electronic mechanical brake (EMB) or other types of brakes without limitation.

[0077] Among them, the drive system 110, the brake system 140 and the vehicle controller 130 are communicatively connected via a CAN network, and the embodiments of the present application do not limit the specific communication connection method. For example, the motor controller in the drive system 110 and the vehicle controller 130 can communicate through a private CAN network, the brake controller 141 of the brake system 140 and the vehicle controller 130 can communicate through a public CAN network, and the brake controller 141 and each wheel-end brake device 142 can communicate through another private CAN network. For another example, the vehicle controller 130 can communicate with the motor controller in the drive system 110 and the brake controller 141 in the brake system 140 through the same CAN network.

[0078] See also Figure 2 (b) The electric vehicle 100 is a four-wheel drive vehicle, and the drive system 110 includes a drive motor 113 for the left front wheel and a motor controller 123 for the drive motor 113, a drive motor 114 for the right front wheel and a motor controller 124 for the drive motor 114, a drive motor 115 for the left rear wheel and a motor controller 125 for the drive motor 115, and a drive motor 116 for the right rear wheel and a motor controller 126 for the drive motor 116.

[0079] The architecture of the embodiment of the present application is described above. The control method of the electric vehicle provided by the present application will be described below in conjunction with a specific embodiment.

[0080] A control method for an electric vehicle provided in an embodiment of the present application is used to control a driving system of the electric vehicle after a track mode of the electric vehicle is started to improve the handling stability of the electric vehicle during track driving.

[0081] The control method of the electric vehicle provided in the embodiment of the present application includes the following steps.

[0082] At the first moment t1, the opening of the accelerator pedal of the electric vehicle is a first accelerator pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, and the drive motor is controlled to output a first torque indicated by the first accelerator pedal opening.

[0083] In the embodiment of the present application, the specific value of the preset slip rate is not limited, and may be, for example, 10%, 15%, 20%, etc.

[0084] In one embodiment, when the user operates the electric vehicle to make the vehicle travel, if the slip rate of the electric vehicle is less than a preset slip rate, it can be considered that the electric vehicle is not slipping and the handling stability of the electric vehicle is good, while if the slip rate of the electric vehicle is greater than or equal to the preset slip rate, it can be considered that the electric vehicle is slipping and the handling stability of the electric vehicle is poor.

[0085] At the first time t1, the electric vehicle is not slipping, and in response to the accelerator pedal opening being a first accelerator pedal opening, controlling the drive motor to output a first torque enables the electric vehicle to travel at an acceleration indicated by the first torque.

[0086] Among them, the acceleration corresponding to the preset slip rate is the maximum acceleration allowed by the current track position of the electric vehicle (for the sake of distinction, it is referred to as the preset acceleration below).

[0087] For easier understanding, see Figure 3 and Figure 4 , Figure 3 A schematic diagram showing a driving scene of an electric vehicle 100 is shown. Figure 4 A schematic diagram of a control method for an electric vehicle 100 is shown.

[0088] At the first moment t1, the electric vehicle travels to Figure 3 As shown in position 1, Figure 4 As shown, the opening of the accelerator pedal is the first accelerator pedal opening, and the torque output by the drive motor is the first torque.

[0089] In one embodiment, a first preset slip rate less than the preset slip rate may also be set. If the slip rate of the electric vehicle is greater than or equal to the first preset slip rate and less than the preset slip rate, it is considered that the friction force on the electric vehicle is in a nonlinear region, that is, the friction force increases nonlinearly with the increase of the slip rate, the acceleration of the electric vehicle is greater than or equal to the acceleration corresponding to the first preset slip rate (hereinafter referred to as the boundary acceleration for the sake of distinction) and less than the preset acceleration, the slip rate of the electric vehicle is less than the first preset slip rate, it is considered that the friction force on the electric vehicle is in a linear region, that is, the friction force increases linearly with the increase of the slip rate, and the acceleration of the electric vehicle is less than the boundary acceleration.

[0090] For easier understanding, see Figure 5 and Figure 6 , Figure 5 A schematic diagram of a friction circle of an electric vehicle 100 is shown. Figure 6 A schematic diagram showing the acceleration of an electric vehicle 100 is shown.

[0091] like Figure 5 As shown, Figure 5510 in the figure is the boundary value of the friction force in the nonlinear region to which the electric vehicle 100 is subjected. At this time, the acceleration of the electric vehicle 100 is as follows: Figure 6 The boundary acceleration shown in 610, Figure 5 520 in the figure is the boundary value of the friction force in the linear region of the electric vehicle 100. At this time, the acceleration of the electric vehicle 100 is as follows: Figure 6 The preset acceleration shown in 620.

[0092] For vehicles that have activated the track mode, when the acceleration of the electric vehicle is greater than or equal to the boundary acceleration and less than the preset acceleration, the vehicle and track characteristics are maximized to provide users with a good racing experience.

[0093] In one case, at a second moment t2 after the first moment t1, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the torque output by the drive motor is actively controlled to be reduced to less than the first torque.

[0094] At the second moment t2, the accelerator pedal opening is still the first accelerator pedal opening. At this time, the slip rate of the electric vehicle is greater than or equal to the preset slip rate. That is to say, the slip rate of the electric vehicle increases compared to the first moment t1 because the adhesion coefficient of the track where the electric vehicle is located decreases.

[0095] At the second moment t2, without responding to the first accelerator pedal opening, the torque output by the drive motor is actively controlled to be reduced to less than the first torque, so that the acceleration of the electric vehicle is less than the acceleration indicated by the first torque, thereby making the slip rate of the electric vehicle less than the preset slip rate, thereby avoiding the electric vehicle from slipping and losing control, so as to improve the handling stability of the electric vehicle.

[0096] At the second moment t2, the electric vehicle travels to Figure 3 Position 2 shown, such as Figure 4 As shown, the adhesion coefficient of the current track position is reduced, the opening of the accelerator pedal is the first accelerator pedal opening, and the torque output by the drive motor is reduced.

[0097] In another embodiment, the slip rate of the electric vehicle is greater than or equal to a preset slip rate, and it can be considered that the electric vehicle is not slipping but is close to slipping. As long as the opening of the accelerator pedal or the adhesion coefficient of the track where the electric vehicle is located increases, the electric vehicle will slip.

[0098] In this embodiment, a first preset slip rate as described in the above embodiment can also be set.

[0099] In addition, in one embodiment, a second preset slip rate greater than the preset slip rate may be set. If the slip rate of the electric vehicle is greater than or equal to the second preset slip rate, the electric vehicle may be considered to be slipping. If the slip rate of the electric vehicle is greater than or equal to the preset slip rate and less than the second preset slip rate, the electric vehicle may be considered to have a high risk of slipping. By actively controlling the drive motor to reduce the torque output when the slip rate of the electric vehicle is greater than or equal to the preset slip rate at the second moment t2, the risk of slipping of the electric vehicle may be reduced.

[0100] By setting the opening of the accelerator pedal at the second moment to be the same as that at the first moment, that is, the first accelerator pedal opening, it is described that in this scenario, the slip rate of the electric vehicle increases to be greater than or equal to the preset slip rate at the second moment and this is not due to the increase in the opening of the accelerator pedal.

[0101] In this embodiment, the electric vehicle is automatically controlled by providing a track mode for the electric vehicle to improve the handling stability of the electric vehicle during the track driving process. Specifically, during the driving process after the electric vehicle starts the track mode (the electric vehicle will accelerate during the process), by automatically controlling the drive motor of the electric vehicle to reduce the torque output when the slip rate of the electric vehicle is greater than or equal to the preset slip rate, the slip rate of the electric vehicle can be reduced to less than the preset slip rate, and the torque output of the drive motor is automatically controlled during the track driving process of the electric vehicle to avoid the electric vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and reducing the user's operating burden. Even drivers with insufficient driving experience can have a good racing experience. In addition, during the track driving process of the electric vehicle, the drive motor is actively controlled to reduce the torque output, rather than responding to the torque signal issued by the vehicle body electronic stability system through the vehicle controller to control the drive motor to reduce the torque output, thereby timely responding to the change in the vehicle slip rate to control the torque output of the drive motor, reducing the control delay of the electric vehicle, further improving the handling stability of the electric vehicle, and ensuring driving safety.

[0102] In one embodiment, at the second moment t2, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is less than the preset slip rate and the difference between the slip rate and the preset slip rate is greater than the preset difference, and the torque output by the active control drive motor is increased to be greater than the first torque.

[0103] When the slip rate of the electric vehicle is less than the preset slip rate and the difference between the slip rate and the preset slip rate is greater than the preset difference, the acceleration of the electric vehicle is much less than the preset acceleration. At this time, it is impossible to maximize the utilization of the whole vehicle and track characteristics and fail to bring a good racing experience to the user. By actively controlling the torque output by the drive motor, the acceleration of the electric vehicle is increased to maximize the utilization of the whole vehicle and track characteristics and bring a good racing experience to the user.

[0104] In one embodiment, at the second time t2, the greater the slip rate of the electric vehicle, the greater the reduction amount of the torque output by the active control driving motor.

[0105] Among them, the greater the slip rate of the electric vehicle, the more serious the slip of the electric vehicle is considered to be.

[0106] Similarly, at the second moment, the smaller the slip rate of the electric vehicle is, the smaller the reduction amount of the torque output by the active control driving motor is.

[0107] In this embodiment, when the electric vehicle is driving on a track, by automatically controlling the reduction in torque output by the drive motor when the slip rate of the electric vehicle is greater than or equal to a preset slip rate and the greater the slip rate, the greater the reduction in torque output by the drive motor can be flexibly controlled according to the slip rate of the electric vehicle, thereby achieving automatic control of the torque output of the drive motor under different slip rates to avoid the electric vehicle from slipping, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0108] In one embodiment, at the second moment t2, the slip rate of the electric vehicle is the first slip rate, and the drive motor is actively controlled to output the third torque; at the second moment, the slip rate of the electric vehicle is the second slip rate, and the drive motor is actively controlled to output the fourth torque; the first slip rate is greater than the second slip rate, and the third torque is less than the fourth torque.

[0109] Wherein, the first slip rate and the second slip rate are both greater than a preset slip rate.

[0110] In this embodiment, when the electric vehicle is driving on a track, when the slip rate of the electric vehicle is greater than or equal to a preset slip rate and the slip rate is large, the torque output by the drive motor is automatically controlled to be smaller; when the slip rate of the electric vehicle is greater than or equal to a preset slip rate and the slip rate is small, the torque output by the drive motor is automatically controlled to be larger. This achieves automatic control of the torque output of the drive motor to prevent the electric vehicle from slipping and losing control, improves the handling stability of the electric vehicle, and ensures driving safety.

[0111] In one embodiment, at a first moment t1, the drive motor is controlled to output a torque indicated by a torque signal; and at a second moment t2, the drive motor is actively controlled to output a torque smaller than the torque indicated by the torque signal.

[0112] In this embodiment, when the electric vehicle is driving on a track, when the slip rate is greater than or equal to the preset slip rate, the torque output by the drive motor is actively controlled to be less than the torque indicated by the torque signal, rather than responding to the torque signal issued by the electronic stability program through the vehicle controller to control the drive motor to adjust the torque output. This achieves timely response to the vehicle's slip rate changes to control the torque output of the drive motor, improves the handling stability of the electric vehicle, and ensures driving safety.

[0113] In another case, at a second moment t2 after the first moment t1, the opening of the accelerator pedal of the electric vehicle is a second accelerator pedal opening greater than the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to a preset slip rate, and the drive motor is actively controlled to adjust the output torque to be less than the second torque indicated by the second accelerator pedal opening.

[0114] At the second moment t2, the accelerator pedal opening is greater than the second accelerator pedal opening of the first accelerator pedal opening, and the slip rate of the electric vehicle is greater than or equal to the preset slip rate. At this time, the increase in slip rate compared to the first moment t1 may be due to the increase in the accelerator pedal opening, or may be due to the increase in the accelerator pedal opening and the decrease in the adhesion coefficient of the track where the electric vehicle is located.

[0115] At the second moment t2, without responding to the second accelerator pedal opening, the torque output by the drive motor is actively controlled to be reduced to a second torque less than the second torque indicated by the second accelerator pedal, so that the slip rate of the electric vehicle is less than the preset slip rate, thereby preventing the electric vehicle from slipping out of control, thereby improving the electric

[0116] For ease of understanding, let's take the example that the increase in the slip rate of an electric vehicle is due to the increase in the opening of the accelerator pedal and the decrease in the adhesion coefficient of the track where the electric vehicle is located. Figure 7 A schematic diagram of a control method for an electric vehicle 100 is shown.

[0117] At the second moment t2, the electric vehicle travels to Figure 3 In position 2 shown, the opening of the accelerator pedal is the second accelerator pedal opening, the adhesion coefficient of the current track position is reduced, and the torque output by the drive motor is less than the second torque.

[0118] Similarly, at the second moment t2, the greater the second accelerator pedal opening, the greater the slip rate of the electric vehicle, and the greater the reduction in the torque output by the active control drive motor.

[0119] In this embodiment, the opening of the accelerator pedal at the second moment is set to be greater than the opening of the accelerator pedal at the first moment, so as to describe that the slip rate of the electric vehicle in this scenario increases to be greater than or equal to the preset slip rate at the second moment because the opening of the accelerator pedal increases. When the electric vehicle is driving on the track, in the case where the slip rate of the electric vehicle is greater than or equal to the preset slip rate due to the increase in the opening of the accelerator pedal operated by the user, the drive motor of the electric vehicle is automatically controlled to reduce the torque output to reduce the slip rate of the electric vehicle to less than the preset slip rate without responding to the opening of the accelerator pedal operated by the user, so that the torque output of the drive motor is automatically controlled to avoid the electric vehicle from slipping out of control during the electric vehicle driving on the track, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0120] In one embodiment, at a first moment t1, the drive motor is controlled to output a torque indicated by a torque signal; and at a second moment t2, the drive motor is actively controlled to output a torque smaller than the torque indicated by the torque signal.

[0121] At the first moment t1 , the torque indicated by the torque signal is a first torque indicated by a first accelerator pedal opening; at the second moment t2 , the torque indicated by the torque signal is a second torque indicated by a second accelerator pedal opening.

[0122] The following will describe in more detail the control method of the electric vehicle proposed in the embodiment of the present application after the track mode of the electric vehicle is started.

[0123] In one embodiment, during driving after the track mode of the electric vehicle is activated, the vehicle body electronic stability system of the electric vehicle is controlled to be turned off.

[0124] The control link of the electronic stability system is: electric vehicle → electronic stability system → vehicle controller → motor controller → electric vehicle. Obviously, the long control link of the electronic stability system leads to insufficient control accuracy and bandwidth, and it is unable to quickly respond to the change of slip rate to control the torque output of the drive motor.

[0125] At the same time, when the electronic stability system is turned on, the maximum acceleration allowed by the ordinary electronic stability system is the boundary acceleration. At this time, the acceleration of the electric vehicle cannot be between the boundary acceleration and the preset acceleration to provide users with a good racing experience.

[0126] In this embodiment, when the electric vehicle is driving on a track, the body electronic stability system of the electric vehicle is controlled to be turned off, so that in this application, the drive motor reduces the torque output not in response to the instruction of the torque signal sent by the body electronic stability system through the vehicle controller, but actively controls the drive motor to reduce the torque output, thereby achieving timely response to changes in the vehicle slip rate to control the torque output of the drive motor, improving the handling stability of the electric vehicle and ensuring driving safety.

[0127] In one embodiment, the control method of the electric vehicle provided in the embodiment of the present application also includes: during the driving process after the track mode of the electric vehicle is started, a preset acceleration is displayed on the dashboard or central control screen of the electric vehicle, and the preset acceleration is used to indicate the maximum acceleration allowed for the current track position of the electric vehicle.

[0128] In the embodiment of the present application, the specific value of the preset acceleration is not limited. The preset acceleration is the acceleration allowed by the road adhesion capacity, and the road adhesion capacity is determined by the adhesion coefficient.

[0129] In one embodiment, the method for calculating a preset acceleration may include: calculating the road adhesion of the electric vehicle at its current track position according to the motor speed indicated by the resolver signal from the resolver sensor, and calculating the preset acceleration of the electric vehicle according to the road adhesion and the weight of the electric vehicle.

[0130] See also Figure 8 , Figure 8 A schematic diagram of a central control screen of an electric vehicle 100 is shown.

[0131] like Figure 8 As shown, Figure 8 810 is the preset acceleration.

[0132] Among them, Figure 8 The central control screen shown is installed on the electric vehicle 100, and the position of the central control screen on the electric vehicle is as shown in FIG. Fig. 9 shown.

[0133] In this embodiment, when the electric vehicle is driving on a track, a preset acceleration is displayed on the instrument panel or central control screen of the electric vehicle, so that the user can obtain the maximum acceleration allowed by the electric vehicle for the current track position, which is beneficial to improving the user's driving experience and confidence, so as to facilitate the subsequent control of the electric vehicle according to the preset acceleration, thereby improving the driving experience.

[0134] In one embodiment, the preset acceleration displayed on the instrument panel or the central control screen is controlled to decrease as the adhesion coefficient of the track position decreases.

[0135] Since the slip rate at the first moment t1 is smaller than the slip rate at the second moment t2, the adhesion coefficient at the track position at the first moment t1 is greater than the adhesion coefficient at the track position at the second moment t2, and the preset acceleration at the first moment t1 is greater than the preset acceleration at the second moment t2.

[0136] In this embodiment, when the electric vehicle is driving on a track, the preset acceleration displayed on the instrument panel or the central control screen is controlled to decrease as the adhesion coefficient of the track position decreases, thereby realizing the preset acceleration displayed on the instrument panel or the central control screen flexibly according to the decrease of the adhesion coefficient at the track position, so that the user can obtain the maximum acceleration allowed by the electric vehicle for the current track position under different adhesion coefficients, which is beneficial to improving the user's driving experience and confidence.

[0137] In one embodiment, the greater the decrease in the adhesion coefficient, the greater the decrease rate of the preset acceleration displayed on the instrument panel or the central control screen of the electric vehicle.

[0138] The greater the decrease in the adhesion coefficient, the greater the decrease in the preset acceleration displayed on the instrument panel or central control screen of the electric vehicle, and the greater the decrease in the preset acceleration within the change cycle of the preset acceleration displayed on the instrument panel or central control screen, that is, the greater the decrease rate.

[0139] In this embodiment, when the electric vehicle is driving on a track, the greater the reduction in the adhesion coefficient, the greater the reduction rate of the preset acceleration displayed on the instrument panel or central control screen of the electric vehicle. This ensures that the preset acceleration can be quickly displayed on the instrument panel or central control screen when the adhesion coefficient is reduced at different track positions. This enables the user to obtain the maximum acceleration allowed by the electric vehicle for the current track position under different adhesion coefficients, which is beneficial to improving the user's driving experience and confidence.

[0140] In one embodiment, during driving after the track mode of the electric vehicle is activated, the drive motor is actively controlled to reduce torque output so that the acceleration of the electric vehicle is less than a preset acceleration displayed on the instrument panel or the central control screen.

[0141] In this embodiment, when the electric vehicle is driving on a track, the user can obtain the value of a preset acceleration. When the acceleration of the electric vehicle is greater than the preset acceleration, the electric vehicle will slip and lose control. By actively controlling the drive motor to reduce the torque output so that the acceleration of the electric vehicle is less than the preset acceleration displayed on the instrument panel or the central control screen, the torque output of the drive motor is automatically controlled when the electric vehicle is in track mode to avoid the electric vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0142] In another embodiment, during driving of the electric vehicle after the track mode is activated, an acceleration indicator is displayed on the instrument panel or central control screen of the electric vehicle; the acceleration indicator includes two display states for indicating that the slip rate of the electric vehicle is less than a preset slip rate and that the slip rate of the electric vehicle is greater than or equal to the preset slip rate.

[0143] The acceleration mark may be a luminous mark, such as an indicator light.

[0144] If the slip rate of the electric vehicle is less than the preset slip rate, it means that the acceleration of the electric vehicle is less than the preset acceleration, and the acceleration indicator lights up green; if the slip rate of the electric vehicle is less than the preset slip rate, it means that the acceleration of the electric vehicle is less than the preset acceleration, and the acceleration indicator lights up red.

[0145] like Figure 8 As shown, Figure 8 The 820 in FIG. 8 is the acceleration mark.

[0146] See also Fig.10 , Fig.10A schematic diagram of a central control screen of an electric vehicle 100 is shown.

[0147] At the first moment t1, the electric vehicle travels to position 1, and the slip rate of the electric vehicle is less than the preset slip rate. Fig.10 In the example, the acceleration mark 1010 presents color 1 (color 1 indicates the green light mentioned above); at the first moment t2, the electric vehicle travels to position 2, the slip rate of the electric vehicle is greater than or equal to the preset slip rate, Fig.10 In the figure, the acceleration mark 1110 presents color 2 (color 2 indicates the red light mentioned above).

[0148] In one embodiment, if the first preset slip rate as described above is provided, the slip rate of the electric vehicle is less than the first preset slip rate, indicating that the acceleration of the electric vehicle is less than the boundary acceleration, and the acceleration indicator is yellow; the slip rate of the electric vehicle is greater than or equal to the first preset slip rate and less than the preset slip rate, indicating that the acceleration of the electric vehicle is greater than or equal to the boundary acceleration and less than the preset acceleration, and the acceleration indicator is green; the slip rate of the electric vehicle is greater than or equal to the preset slip rate, indicating that the acceleration of the electric vehicle is greater than or equal to the preset acceleration, and the acceleration indicator is red.

[0149] In this embodiment, when the electric vehicle is driving on a track, the user can accurately obtain whether the electric vehicle is slipping and whether the acceleration of the electric vehicle is greater than or equal to the preset acceleration through the display status of the acceleration indicator. The user can take corresponding measures for the slipping or sliding wheels based on this information, thereby improving driving safety, while also helping to improve the user's driving experience and confidence.

[0150] In one embodiment, an acceleration mark is displayed on the right side of the preset acceleration of the electric vehicle on the central control screen; the size of the preset acceleration mark is larger than the size of the acceleration mark.

[0151] In this embodiment, an acceleration mark is displayed on the right side of the preset acceleration of the electric vehicle on the central control screen; the size of the preset acceleration mark is larger than the size of the acceleration mark, so that the user can obtain the information indicated by the preset acceleration and the acceleration mark, and the arrangement method is reasonable, and the user can obtain the information more easily. By making the size of the preset acceleration larger than the size of the acceleration mark, the preset acceleration is more eye-catching on the central control screen, so that the user can obtain the preset acceleration of the electric vehicle first and detect the change of the preset acceleration in time, thereby improving the driving experience.

[0152] In one embodiment, during the driving process of the electric vehicle after the track mode is activated, the slip rate of the electric vehicle is calculated according to the motor speed indicated by the resolver sensor of the drive motor.

[0153] In one embodiment, a mapping relationship between the motor speed indicated by the resolver signal and the slip rate of the electric vehicle can be established, and the slip rates of the four wheels can be determined based on the mapping relationship and the motor speed indicated by the current resolver signal. Then, the slip rate of the electric vehicle can be calculated based on the slip rates of the four wheels.

[0154] The slip rate of the electric vehicle may be an average value of the slip rates of the four wheels, or a weighted average value of the slip rates of the four wheels, and the weighting factor may be, for example, the vertical loads of the four wheels.

[0155] In another embodiment, the wheel speed of the electric vehicle can be calculated based on the resolver signal indicated by the resolver sensor, the vehicle speed of the electric vehicle can be calculated based on the motor torque indicated by the motor torque signal, and the slip rate of the electric vehicle can be calculated based on the vehicle speed and the wheel speed of the electric vehicle.

[0156] The wheel speed of the electric vehicle may be an average of the wheel speeds of the four wheels, or a weighted average of the wheel speeds of the four wheels, with the weighting coefficient being, for example, the diameters of the four wheels.

[0157] Similarly, the slip rate of the electric vehicle during braking can be calculated according to the control method provided in this embodiment.

[0158] In this embodiment, the resolver signal is a signal that can be directly obtained by the motor controller. The resolver signal indicates the motor speed. Compared with the wheel speed signal, the resolver signal has higher accuracy and better stability. The slip rate can be calculated quickly and accurately based on the resolver signal.

[0159] In one embodiment, during the driving process of the electric vehicle after the track mode is activated, the torque data output by the drive motor during the driving on the track is obtained and stored in the target storage space; during the driving process of the electric vehicle after the track mode is activated next time, the torque data is obtained from the target storage space, and the torque output of the drive motor is controlled according to the torque data.

[0160] The embodiment of the present application does not limit the specific type of the target storage space, which may be, for example, the cloud, the local storage space of the electric vehicle, etc.

[0161] Among them, the data associated with the torque output and stored in the target storage space also include the track and time point for obtaining the torque data, the track position corresponding to the time point, the preset acceleration corresponding to each track position, etc.

[0162] During the driving process after the electric vehicle starts the track mode next time, the torque output of the drive motor is controlled according to the corresponding torque data at the corresponding track position.

[0163] At the same time, during this driving process, the control method provided in the embodiment of the present application will also monitor the slip rate of the electric vehicle, make corresponding adjustments to the torque output of the drive motor, and store the adjusted torque data in the target storage space to update the torque data stored for the track.

[0164] In this embodiment, when the electric vehicle is driving on the track, by acquiring the torque data output by the drive motor during the driving process on the track and storing it in the target storage space, it is beneficial to analyze whether the acceleration of the electric vehicle is close to the preset acceleration at each track position, so as to provide users with a better racing experience. At the same time, when the electric vehicle is driving after starting the track mode next time, the torque data is acquired from the target storage space, and the torque output of the drive motor is controlled according to the torque data, which can reduce the automatic control cost while improving the stability of the electric vehicle and ensuring driving safety.

[0165] When an electric vehicle is driving on a track and enters a curve, the lateral force that the wheels need to withstand increases. If the electric vehicle does not reduce its speed before entering the curve and enters the curve at too high a speed, the wheels will not be able to withstand such a huge lateral force, resulting in a decrease in grip and the handling stability of the electric vehicle. Therefore, before the electric vehicle enters the curve, the user can operate the brake pedal to brake the electric vehicle.

[0166] In view of this, an embodiment of the present application provides a control method for an electric vehicle, the control method comprising: at a third moment t3 after the first moment t1, the accelerator pedal opening is reduced to zero, the brake pedal opening is the first brake pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, and the braking system of the electric vehicle is controlled to output braking force.

[0167] In the embodiment of the present application, the specific value of the preset slip rate is not limited, and may be, for example, 10%, 15%, 20%, etc.

[0168] Among them, if the slip rate of the electric vehicle is less than the preset slip rate, it can be considered that the electric vehicle is not slipping and the handling stability of the electric vehicle is good; if the slip rate of the electric vehicle is greater than or equal to the preset slip rate, it can be considered that the electric vehicle is slipping and the handling stability of the electric vehicle is poor.

[0169] At the third time t3, the electric vehicle is not slipping, and in response to the brake pedal opening being the first brake pedal opening, the brake system is controlled to output a braking force so that the electric vehicle travels at a deceleration indicated by the braking force.

[0170] The deceleration corresponding to the preset slip rate is the maximum deceleration allowed by the current track position of the electric vehicle.

[0171] For ease of understanding, Fig.11A schematic diagram of a control method for an electric vehicle 100 is shown.

[0172] At the third moment t3, the electric vehicle travels to Figure 3 Position 3 shown, such as Fig.11 As shown, the opening of the accelerator pedal is 0, the opening of the brake pedal is the first brake pedal opening, and the braking system outputs a braking force.

[0173] At a fourth moment t4 after the third moment t3, the opening of the brake pedal is the first brake pedal opening and the slip ratio of the electric vehicle is greater than or equal to the preset slip ratio, and the brake system of the electric vehicle is actively controlled to reduce the braking force output.

[0174] At the fourth moment t4, the opening of the brake pedal is still the first brake pedal opening. At this time, the slip rate of the electric vehicle is greater than or equal to the preset slip rate, that is, the increase in the slip rate of the electric vehicle is due to the decrease in the adhesion coefficient of the track where the electric vehicle is located.

[0175] At the fourth moment t4, without responding to the first brake pedal opening, the braking system of the electric vehicle is actively controlled to reduce the braking force output, and the deceleration of the electric vehicle is less than the deceleration at the third moment t3, so that the slip rate of the electric vehicle is less than the preset slip rate, thereby avoiding the electric vehicle from slipping and ensuring the handling stability of the electric vehicle.

[0176] At the fourth moment t4, the electric vehicle travels to Figure 3 Position 4 shown, such as Fig.11 As shown, the adhesion coefficient of the current track position is reduced, the opening of the brake pedal is the first brake pedal opening, and the braking force output by the braking system is reduced.

[0177] In this embodiment, when the electric vehicle is running on the track, in response to the brake pedal opening being greater than zero, the brake system is controlled to output braking force to brake the electric vehicle. In this process, when the slip rate of the electric vehicle is greater than or equal to the preset slip rate, the brake system of the electric vehicle is automatically controlled to reduce the braking force output so that the slip rate of the electric vehicle is reduced to less than the preset slip rate, so that when the electric vehicle is decelerating on the track, the torque output of the drive motor is automatically controlled to prevent the electric vehicle from slipping out of control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0178] In one embodiment, at the fourth time t4, the greater the slip ratio of the electric vehicle, the greater the reduction amount of the braking force output by the active control braking system.

[0179] Among them, the greater the slip rate of the electric vehicle, the more serious the slip of the electric vehicle is considered to be.

[0180] Similarly, at the fourth moment, the smaller the slip ratio of the electric vehicle is, the smaller the reduction in the braking force output by the active control braking system is.

[0181] In one embodiment, at the third moment t3, the braking system is controlled to output the braking force indicated by the braking signal; at the fourth moment t4, the braking force output by the active control braking system is smaller than the braking force indicated by the braking signal.

[0182] In this embodiment, when the electric vehicle is driving on a track, the reduction in the braking force output by the braking system is automatically controlled to be greater than or equal to a preset slip rate and the greater the slip rate, the greater the reduction. The reduction in the braking force output by the braking system can be flexibly controlled according to the slip rate of the electric vehicle, thereby achieving automatic control of the braking force output by the braking system under different slip rates to prevent the electric vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0183] The embodiment of the present application provides a motor controller for an electric vehicle 100 , and the motor controller is used to execute the control method of the electric vehicle provided in the above embodiment.

[0184] The motor controller provided in the embodiment of the present application is used to control the drive system of the electric vehicle after the track mode of the electric vehicle is started to improve the handling stability of the electric vehicle when driving on the track.

[0185] The motor controller is specifically used for: at a first moment t1, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, controlling the drive motor to output a first torque indicated by the first accelerator pedal opening; at a second moment t2 after the first moment t1, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, actively controlling the torque output by the drive motor to be reduced to less than the first torque.

[0186] For ease of understanding, Fig.12 A motor controller for an electric vehicle 100 is shown.

[0187] like Fig.12As shown, after the electric vehicle starts the track mode, a track mode enable signal, a gear signal and a pedal signal are sent to the vehicle controller. If the track mode enable signal indicates that the track mode is enabled, the gear signal indicates the forward gear and the pedal signal indicates that the opening of the accelerator pedal is greater than zero, at the first moment t1, the vehicle controller responds to the opening of the accelerator pedal and sends a torque signal to the motor controller, so that the motor controller controls the drive motor to output the torque indicated by the torque signal. At the second moment t2, the motor controller calculates the slip rate according to the resolver signal sent from the resolver sensor. If the slip rate is greater than or equal to the preset slip rate, the drive motor is actively controlled to reduce the torque output.

[0188] If the track mode enable signal indicates that the track mode is enabled, the gear signal indicates the forward gear, and the pedal signal indicates that the opening of the brake pedal is greater than zero, at the third moment t3, the vehicle controller responds to the opening of the brake pedal and sends a braking signal to the motor controller, so that the motor controller controls the braking system to output the braking force indicated by the braking signal. At the second moment t2, the motor controller calculates the slip rate according to the resolver signal sent from the resolver sensor. If the slip rate is greater than or equal to the preset slip rate, the braking system is actively controlled to reduce the braking force output.

[0189] In this embodiment, when the electric vehicle is driving on a track, when the slip rate is greater than or equal to a preset slip rate, the motor controller directly controls the drive motor to reduce the torque output, rather than responding to the instruction of the torque signal sent by the electronic stability program through the vehicle controller to control the drive motor to reduce the torque output. This decouples the operation of the motor controller and the drive motor from the vehicle controller, so that after the slip rate increases, the motor controller can actively control the drive motor of the electric vehicle to reduce the torque output and promptly avoid the vehicle from slipping and losing control, thereby improving the handling stability of the electric vehicle and ensuring driving safety.

[0190] In another embodiment of the present application, an electric vehicle is further provided, the electric vehicle comprising four drive motors and a motor controller, wherein:

[0191] At a first moment, the opening of the accelerator pedal of the electric vehicle is a first accelerator pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, and the motor controller is used to control the drive motor to output a first torque indicated by the first accelerator pedal opening;

[0192] At a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the motor controller is used to actively control the torque output by the drive motor to be reduced to less than the first torque.

[0193] It can be understood that all relevant contents of each step involved in the above method embodiment can be referred to the embodiment of the controller and the embodiment of the electric vehicle, and the embodiments of the present application will not be repeated here.

[0194] Finally, it should be noted that the above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application 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 an electric vehicle, characterized in that: The control method is used to control the driving system of the electric vehicle after the track mode of the electric vehicle is started to improve the handling stability of the electric vehicle when driving on a track, and the control method includes: At a first moment, the opening of the accelerator pedal of the electric vehicle is a first accelerator pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, and the drive motor is controlled to output a first torque indicated by the first accelerator pedal opening; At a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the torque output by the drive motor is actively controlled to be reduced to less than the first torque.

2. The control method according to claim 1, characterized in that: The control method further comprises: At a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is a second accelerator pedal opening greater than the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the drive motor is actively controlled to adjust the output torque to be less than the second torque indicated by the second accelerator pedal opening.

3. The control method according to claim 1, characterized in that: The control method further comprises: During the driving process after the track mode of the electric vehicle is started, the body electronic stability system of the electric vehicle is controlled to be turned off.

4. The control method according to claim 1, characterized in that: The control method further comprises: During driving after the track mode of the electric vehicle is activated, a preset acceleration is displayed on the instrument panel or central control screen of the electric vehicle, and the preset acceleration is used to indicate the maximum acceleration allowed at the current track position of the electric vehicle.

5. The control method according to claim 4, characterized in that: The control method specifically includes: The preset acceleration displayed on the instrument panel or the central control screen is controlled to decrease as the adhesion coefficient of the track position decreases.

6. The control method according to claim 4, characterized in that: The control method specifically includes: The greater the decrease in the adhesion coefficient, the greater the decrease rate of the preset acceleration displayed on the instrument panel or the central control screen of the electric vehicle.

7. The control method according to claim 4, characterized in that: The control method further comprises: During driving after the track mode of the electric vehicle is activated, the drive motor is actively controlled to reduce torque output so that the acceleration of the electric vehicle is less than the preset acceleration displayed on the instrument panel or the central control screen.

8. The control method according to claim 1, characterized in that: The control method specifically includes: At the first moment, controlling the drive motor to output a torque indicated by a torque signal; At the second moment, the torque output by the drive motor is actively controlled to be smaller than the torque indicated by the torque signal.

9. The control method according to claim 1, characterized in that: The control method specifically includes: At the second moment, the greater the slip rate of the electric vehicle, the greater the reduction amount of the torque output by the drive motor is actively controlled.

10. The control method according to claim 1, characterized in that: The control method specifically includes: During the driving process of the electric vehicle after the track mode is activated, the slip rate of the electric vehicle is calculated according to the motor speed indicated by the resolver sensor of the drive motor.

11. The control method according to claim 1, characterized in that: The control method further comprises: During driving after the track mode of the electric vehicle is activated, an acceleration indicator is displayed on the instrument panel or central control screen of the electric vehicle; The acceleration indicator includes two display states for indicating that the slip rate of the electric vehicle is less than the preset slip rate and that the slip rate of the electric vehicle is greater than or equal to the preset slip rate.

12. The control method according to claim 1, characterized in that: The control method further comprises: During the driving process of the electric vehicle after the track mode is started, obtaining torque data output by the drive motor during the driving process on the track and storing the data in a target storage space; During the driving process of the electric vehicle after the track mode is started next time, the torque data is obtained from the target storage space, and the torque output of the drive motor is controlled according to the torque data.

13. The control method according to claim 1, characterized in that: The control method further comprises: At a third moment after the first moment, the accelerator pedal opening is reduced to zero, the brake pedal opening is a first brake pedal opening, and the slip rate of the electric vehicle is less than a preset slip rate, and the brake system of the electric vehicle is controlled to output a braking force; At a fourth moment after the third moment, the opening of the brake pedal is the first brake pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the braking system of the electric vehicle is actively controlled to reduce the braking force output.

14. A motor controller, characterized in that: The motor controller is used to control the driving system of the electric vehicle after the track mode of the electric vehicle is started to improve the handling stability of the electric vehicle when driving on the track. The motor controller is specifically used to: At a first moment, the opening of the accelerator pedal of the electric vehicle is a first accelerator pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, and the drive motor is controlled to output a first torque indicated by the first accelerator pedal opening; At a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the torque output by the drive motor is actively controlled to be reduced to less than the first torque.

15. An electric vehicle, characterized in that: The electric vehicle comprises four drive motors and a motor controller as claimed in claim 14; wherein: At a first moment, the opening of the accelerator pedal of the electric vehicle is a first accelerator pedal opening and the slip rate of the electric vehicle is less than a preset slip rate, and the motor controller is used to control the drive motor to output a first torque indicated by the first accelerator pedal opening; At a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is the first accelerator pedal opening and the slip rate of the electric vehicle is greater than or equal to the preset slip rate, and the motor controller is used to actively control the torque output by the drive motor to be reduced to less than the first torque.

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