Traction control method and system of electric vehicle and electric vehicle

Abstract

The present invention discloses a traction control method and system for an electric vehicle. The traction control method comprises: obtaining current gear information, current wheel speed of a driving wheel, and current wheel speed of a non-driving wheel when the electric vehicle is climbing a slope on an open road, determining the current vehicle speed of the electric vehicle according to the current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel, and controlling the current driving torque of a motor according to the current vehicle speed; if it is a forward gear, determining the current vehicle speed of the electric vehicle according to the current wheel speed of the driving wheel, and controlling the current driving torque of the motor to be the driving torque corresponding to the current vehicle speed; if it is a reverse gear, determining the current vehicle speed of the electric vehicle according to the current wheel speed of the non-driving wheel; judging whether the current vehicle speed is greater than a preset vehicle speed threshold; if so, controlling the current driving torque to be 0 N·m; if not, controlling the current driving torque to be the driving torque corresponding to the current vehicle speed, so as to improve the uphill performance of the vehicle when in reverse gear.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric vehicles, and in particular relates to a traction control method and system for an electric vehicle and the electric vehicle. Background Art

[0002] In the existing electric vehicle traction control methods, the electric vehicle calculates the current vehicle speed based on the current wheel speed of the driving wheel when in forward gear (D gear) and reverse gear (R gear), and then performs traction control based on the current vehicle speed, that is, determines the driving torque based on the current vehicle speed. In addition, when the electric vehicle is driving in reverse gear, in order to ensure the driving safety of the electric vehicle, the powertrain traction will be torque-limited when the current vehicle speed of the electric vehicle is too high, and the powertrain traction of the vehicle will no longer provide torque output.

[0003] Generally speaking, when an electric vehicle is driving in reverse on an open road (where the adhesion coefficients of the roads on both sides of the wheels are different), the driving wheel on the side with a low adhesion coefficient will slip due to the low adhesion coefficient of the road, while the non-driving wheel will not slip due to the lack of driving force. At this time, the current driving wheel speed will be higher than the current non-driving wheel speed. At this time, if the electric vehicle is driving uphill in reverse gear on an open road, in order to ensure the driving safety of the electric vehicle, when the current vehicle speed calculated based on the current driving wheel speed is too high, the powertrain traction will be torque-limited. The powertrain traction of the vehicle will no longer provide torque output as the torque is limited, resulting in a decrease in the vehicle's climbing ability when driving uphill in reverse gear. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that in order to ensure the driving safety of an electric vehicle when driving uphill in reverse gear on an open road, when the vehicle speed calculated according to the current driving wheel speed is too high, the powertrain traction force will be torque-limited. At this time, the powertrain traction force of the vehicle will no longer provide torque output due to the torque limitation, resulting in a decrease in the climbing ability of the vehicle when driving uphill in reverse gear. The present invention provides a traction control method for an electric vehicle, which can improve the uphill performance of the vehicle when driving in reverse gear.

[0005] In order to solve the above technical problems, the embodiment of the present invention discloses a traction control method of an electric vehicle, wherein the electric vehicle includes a driving wheel and a non-driving wheel, and the traction control method includes:

[0006] The current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel of the electric vehicle when the electric vehicle is climbing a slope on a double-sided road are obtained, the current vehicle speed of the electric vehicle is determined according to the current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel, and the current driving torque of the motor is controlled according to the current vehicle speed; wherein,

[0007] If the current gear information is the forward gear, the current speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of the control motor is controlled to be the driving torque corresponding to the current speed;

[0008] If the current gear information is reverse gear, the current speed of the electric vehicle is determined according to the current wheel speed of the non-driving wheel; and whether the current speed is greater than a preset speed threshold is determined;

[0009] If yes, the current driving torque of the control motor is 0N·m;

[0010] If not, the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed.

[0011] By adopting the above technical solution, when the electric vehicle is climbing a slope on an open road, the current gear information of the electric vehicle, the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel are obtained; if the current gear information is a forward gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed; if the current gear information is a reverse gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the non-driving wheel, and it is determined whether the current vehicle speed is greater than a preset vehicle speed threshold; if so, the current driving torque of the motor is controlled to be 0 N·m; if not, the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed. This not only ensures the uphill performance in the forward gear, but also because when the electric vehicle is reversing on an open road, the current wheel speed of the non-driving wheels will be lower than the current wheel speed of the driving wheels. Therefore, the current vehicle speed determined based on the current wheel speed of the non-driving wheels will be lower than the current vehicle speed determined based on the current wheel speed of the driving wheels. This can effectively avoid or delay the torque limiting control of the current motor driving torque, thereby improving the uphill performance of the vehicle in reverse gear.

[0012] According to another specific embodiment of the present invention, in the traction control method of an electric vehicle disclosed in the embodiment of the present invention, the vehicle speed threshold is 30 km / h.

[0013] With the above technical solution, the vehicle speed threshold is 30km / h, which is within the controllable speed range and can ensure the reverse driving safety of the electric vehicle.

[0014] According to another specific embodiment of the present invention, in the traction control method of the electric vehicle disclosed in the embodiment of the present invention, the current wheel speed of the driving wheel includes the current wheel speed of the left driving wheel and the current wheel speed of the right driving wheel.

[0015] By adopting the above technical solution, the current wheel speed of the driving wheel is determined by taking into account the current wheel speed of the left driving wheel and the current wheel speed of the right driving wheel, which can improve the accuracy of determining the current speed of the electric vehicle according to the current wheel speed of the driving wheel.

[0016] According to another specific embodiment of the present invention, the traction control method of the electric vehicle disclosed in the embodiment of the present invention determines the current vehicle speed according to the current wheel speed of the driving wheel by calculating the following formula:

[0017]

[0018] Among them, v 车 is the current vehicle speed, v 左驱 is the current wheel speed of the left driving wheel, v 右驱 is the current wheel speed of the right driving wheel.

[0019] By adopting the above technical solution, when determining the current vehicle speed according to the current wheel speed of the driving wheel, the current vehicle speed calculated according to the average value of the current wheel speed of the left driving wheel and the current wheel speed of the right driving wheel has higher accuracy.

[0020] According to another specific embodiment of the present invention, in the traction control method of an electric vehicle disclosed in the embodiment of the present invention, the current wheel speed of the non-driven wheel includes the current wheel speed of the left non-driven wheel and the current wheel speed of the right non-driven wheel.

[0021] By adopting the above technical solution, the current wheel speed of the non-driven wheel is determined by taking into account the current wheel speed of the left non-driven wheel and the current wheel speed of the right non-driven wheel, which can improve the accuracy of determining the current speed of the electric vehicle based on the current wheel speed of the non-driven wheel.

[0022] According to another specific embodiment of the present invention, the traction control method of the electric vehicle disclosed in the embodiment of the present invention determines the current vehicle speed according to the current wheel speed of the non-driving wheel by calculating the following formula:

[0023]

[0024] Among them, v 车 is the current vehicle speed, v 左非驱 is the current wheel speed of the left non-driven wheel, v 右非驱 is the current wheel speed of the right non-driven wheel.

[0025] By adopting the above technical solution, when determining the current vehicle speed according to the current wheel speed of the non-driving wheel, the current vehicle speed calculated according to the average value of the current wheel speed of the left non-driving wheel and the current wheel speed of the right non-driving wheel has higher accuracy.

[0026] The embodiment of the present invention also discloses a traction control system of an electric vehicle, which is used to execute the traction control method of the electric vehicle. The traction control system includes a first controller, a second controller and a sensor; the second controller is connected to the first controller and the sensor respectively; wherein

[0027] The first controller is used to obtain and send the current gear information of the electric vehicle when it is climbing the slope of the open road to the second controller, and the gear information includes forward gear and reverse gear;

[0028] A sensor, used for detecting and sending the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel of the electric vehicle to the second controller;

[0029] a second controller, for receiving current gear information, current wheel speed of the driving wheel and current wheel speed of the non-driving wheel, and determining the current speed of the electric vehicle according to the current gear information, the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel, and controlling the current driving torque of the motor according to the current speed;

[0030] If the current gear information is a forward gear, the second controller determines the current speed of the electric vehicle according to the current wheel speed of the driving wheel, and controls the current driving torque of the motor to be the driving torque corresponding to the current speed;

[0031] If the current gear information is reverse gear, the second controller determines the current speed of the electric vehicle according to the current wheel speed of the non-driving wheel, and determines whether the current speed is greater than a preset speed threshold;

[0032] If yes, the second controller controls the current driving torque of the motor to be 0 N·m;

[0033] If not, the second controller controls the current driving torque of the motor to be the driving torque corresponding to the current vehicle speed.

[0034] According to the above technical solution, when the electric vehicle is climbing a slope on a road, the first controller receives the current gear information of the electric vehicle, and the sensors detect the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel of the electric vehicle. The second controller receives and determines the current vehicle speed of the electric vehicle according to the current gear information, the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel, and controls the current driving torque of the motor according to the current vehicle speed, wherein if the current gear information is a forward gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed; if the current gear information is a reverse gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the non-driving wheel, and it is determined whether the current vehicle speed is greater than the preset vehicle speed threshold; if so, the current driving torque of the motor is controlled to be 0N·m; if not, the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed. This not only ensures the uphill performance in the forward gear, but also because when the electric vehicle is reversing on an open road, the current wheel speed of the non-driving wheels will be lower than the current wheel speed of the driving wheels. Therefore, the current vehicle speed determined based on the current wheel speed of the non-driving wheels will be lower than the current vehicle speed determined based on the current wheel speed of the driving wheels. This can effectively avoid or delay the torque limiting control of the current motor driving torque, thereby improving the uphill performance of the vehicle in reverse gear.

[0035] According to another specific embodiment of the present invention, in the traction control system of the electric vehicle disclosed in the embodiment of the present invention, the first controller is a vehicle controller, and the second controller is a traction controller.

[0036] By adopting the above technical solution, the first controller is the vehicle controller, and the second controller is the traction controller. It is not necessary to set up an additional controller separately, thereby reducing the manufacturing cost.

[0037] According to another specific embodiment of the present invention, in the traction control system of the electric vehicle disclosed in the embodiment of the present invention, the sensor is a wheel speed sensor.

[0038] The embodiment of the present invention further discloses an electric vehicle, including the traction control system of the electric vehicle.

[0039] The beneficial effects of the present invention are:

[0040] The present invention provides a traction control method and system for an electric vehicle, and the electric vehicle. When the electric vehicle is climbing a slope on an open road, current gear information, current wheel speed of a driving wheel, and current wheel speed of a non-driving wheel of the electric vehicle are obtained. If the current gear information is a forward gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of a motor is controlled to be the driving torque corresponding to the current vehicle speed. If the current gear information is a reverse gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the non-driving wheel, and it is judged whether the current vehicle speed is greater than a preset vehicle speed threshold. If so, the current driving torque of the motor is controlled to be 0 N·m; if not, the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed. This not only ensures the uphill performance in the forward gear, but also because when the electric vehicle is reversing on an open road, the current wheel speed of the non-driving wheels will be lower than the current wheel speed of the driving wheels. Therefore, the current vehicle speed determined based on the current wheel speed of the non-driving wheels will be lower than the current vehicle speed determined based on the current wheel speed of the driving wheels. This can effectively avoid or delay the torque limiting control of the current motor driving torque, thereby improving the uphill performance of the vehicle in reverse gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a flow chart of a traction control method for an electric vehicle according to Embodiment 1 of the present invention;

[0042] Figure 2 This is a structural block diagram of a traction control system for an electric vehicle according to embodiment 2 of the present invention.

[0043] Description of reference numerals:

[0044] 100: first controller; 200: second controller; 300: sensor. DETAILED DESCRIPTION

[0045] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may extend based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0046] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0047] In the description of this embodiment, it should be noted that the terms “first”, “second”, etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0048] In the description of this embodiment, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0050] Example 1

[0051] The embodiment of the present invention discloses a traction control method for an electric vehicle. The electric vehicle includes a driving wheel and a non-driving wheel. The traction control method includes: obtaining current gear information, current wheel speed of the driving wheel, and current wheel speed of the non-driving wheel when the electric vehicle is climbing a slope on a split road, determining the current vehicle speed of the electric vehicle according to the current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel, and controlling the current driving torque of the motor according to the current vehicle speed.

[0052] It should be noted that, in this embodiment, the split road surface refers to a road surface with different adhesion coefficients on both sides of the vehicle wheels, such as an icy and snowy road surface. Generally speaking, when arranging a split road surface in a vehicle test, the adhesion coefficient of the road surface on one side of the vehicle wheels is less than 0.3, and the adhesion coefficient of the road surface on the other side is greater than 0.8. The road surface with an adhesion coefficient less than 0.3 is generally a tiled road surface with splashing water.

[0053] Among them, Figure 1As shown, if the current gear information is forward gear, the current speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of the control motor is the driving torque corresponding to the current speed. If the current gear information is reverse gear, the current speed of the electric vehicle is determined according to the current wheel speed of the non-driving wheel; it is determined whether the current speed is greater than the preset speed threshold; if so, the current driving torque of the control motor is 0N·m; if not, the current driving torque of the control motor is the driving torque corresponding to the current speed.

[0054] It should be noted that in this embodiment, the current driving torque of the motor can be controlled to be the driving torque corresponding to the current vehicle speed according to a preset MAP diagram of the current vehicle speed and the current driving torque of the motor, and this embodiment does not make any specific limitation to this.

[0055] When an electric vehicle is in reverse gear and climbing a slope, in order to improve the safety of the electric vehicle climbing, if the current vehicle speed is greater than the preset vehicle speed threshold, the current driving torque of the motor will be limited. At this time, the traction of the electric vehicle's powertrain will no longer provide torque output as the torque is limited, that is, the current driving torque of the motor is controlled to be 0N·m, resulting in a decrease in the climbing ability of the vehicle when it is in reverse gear and climbing uphill. In addition, when an electric vehicle is driving in reverse on a road, the driving wheel on the side with a low adhesion coefficient will slip due to the low adhesion coefficient of the road, while the non-driving wheel will not slip due to the lack of driving force. The speed calculated by the car based on the wheel speed of the left and right non-driving wheels will not increase due to the slip of the wheel on the side with a low adhesion coefficient.

[0056] By adopting the above technical solution, when an electric vehicle is climbing a slope on an open road, the current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel of the electric vehicle are obtained. If the current gear information is a forward gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed; if the current gear information is a reverse gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the non-driving wheel, and it is determined whether the current vehicle speed is greater than the preset vehicle speed threshold; if so, the current driving torque of the motor is controlled to be 0N·m; if not, the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed. In this way, not only can the uphill performance in the forward gear be guaranteed, but also the torque limiting control of the current motor driving torque can be effectively avoided or delayed, thereby improving the uphill performance of the vehicle in the reverse gear.

[0057] In a specific implementation, the vehicle speed threshold is 30 km / h.

[0058] In a specific implementation, the current wheel speeds of the driving wheels include the current wheel speed of the left driving wheel and the current wheel speed of the right driving wheel.

[0059] In a specific implementation, the current vehicle speed is determined based on the current wheel speed of the driving wheel by using the following formula:

[0060]

[0061] Among them, v 车 is the current vehicle speed, v 左驱 is the current wheel speed of the left driving wheel, v 右驱 is the current wheel speed of the right driving wheel.

[0062] By adopting the above technical solution, when determining the current vehicle speed according to the current wheel speed of the driving wheel, the current vehicle speed calculated according to the average value of the current wheel speed of the left driving wheel and the current wheel speed of the right driving wheel has higher accuracy.

[0063] In a specific implementation, the current wheel speed of the non-driven wheels includes the current wheel speed of the left non-driven wheel and the current wheel speed of the right non-driven wheel.

[0064] In a specific implementation, the current vehicle speed is determined based on the current wheel speed of the non-driven wheel by using the following formula:

[0065]

[0066] Among them, v 车 is the current vehicle speed, v 左非驱 is the current wheel speed of the left non-driven wheel, v 右非驱 is the current wheel speed of the right non-driven wheel.

[0067] By adopting the above technical solution, when determining the current vehicle speed according to the current wheel speed of the non-driving wheel, the current vehicle speed calculated according to the average value of the current wheel speed of the left non-driving wheel and the current wheel speed of the right non-driving wheel has higher accuracy.

[0068] The present invention provides a traction control method for an electric vehicle. Different vehicle speed calculation methods are selected according to forward gear and reverse gear, and the output of the vehicle traction is controlled according to different methods, so that the vehicle has better driving performance and climbing performance when climbing on a flat road.

[0069] Example 2

[0070] The embodiment of the present invention further discloses a traction control system of an electric vehicle, which is used to execute the traction control method of the electric vehicle, such as Figure 2 As shown, the traction control system includes a first controller 100, a second controller 200 and a sensor 300; the second controller 200 is connected to the first controller 100 and the sensor 300 respectively; wherein

[0071] The first controller 100 is used to obtain and send the current gear information of the electric vehicle when it is climbing a slope on a road to the second controller 200, and the gear information includes forward gear and reverse gear. In this embodiment, the first controller 100 can be a vehicle controller or a separate controller. In addition, the first controller 100 can be connected to a CAN bus to obtain the current gear information from the CAN bus.

[0072] The sensor 300 is used to detect and send the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel of the electric vehicle to the second controller 200. The sensor 300 can be arranged on each driving wheel and non-driving wheel of the vehicle to obtain the current wheel speed of each driving wheel and non-driving wheel respectively.

[0073] The second controller 200 is used to receive the current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel, and determine the current speed of the electric vehicle according to the current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel, and control the current driving torque of the motor according to the current speed. In this embodiment, the second controller 200 can be a traction controller or a separately set controller, which is not specifically limited in this embodiment.

[0074] Among them, if the current gear information is the forward gear, the second controller 200 determines the current speed of the electric vehicle according to the current wheel speed of the driving wheel, and controls the current driving torque of the motor to be the driving torque corresponding to the current speed.

[0075] If the current gear information is reverse gear, the second controller 200 determines the current speed of the electric vehicle according to the current wheel speed of the non-driving wheel, and determines whether the current speed is greater than the preset speed threshold; if so, the second controller 200 controls the current driving torque of the motor to be 0 N·m; if not, the second controller 200 controls the current driving torque of the motor to be the driving torque corresponding to the current speed.

[0076] By adopting the above technical solution, when the electric vehicle is climbing a slope on a road, the current gear information of the electric vehicle is received by the first controller 100, and the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel of the electric vehicle are detected by the sensor 300. The current speed of the electric vehicle is received by the second controller 200 and determined according to the current gear information, the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel, and the current driving torque of the motor is controlled according to the current speed, wherein if the current gear information is a forward gear, the current speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of the motor is controlled to be the driving torque corresponding to the current speed; if the current gear information is a reverse gear, the current speed of the electric vehicle is determined according to the current wheel speed of the non-driving wheel, and it is determined whether the current speed is greater than the preset speed threshold; if so, the current driving torque of the motor is controlled to be 0N·m; if not, the current driving torque of the motor is controlled to be the driving torque corresponding to the current speed. This not only ensures the uphill performance in the forward gear, but also because when the electric vehicle is reversing on an open road, the current wheel speed of the non-driving wheels will be lower than the current wheel speed of the driving wheels. Therefore, the current vehicle speed determined based on the current wheel speed of the non-driving wheels will be lower than the current vehicle speed determined based on the current wheel speed of the driving wheels. This can effectively avoid or delay the torque limiting control of the current motor driving torque, thereby improving the uphill performance of the vehicle in reverse gear.

[0077] In a specific implementation, the first controller 100 is a vehicle controller, and the second controller 200 is a traction controller.

[0078] In a specific implementation, the sensor 300 is a wheel speed sensor.

[0079] Example 3

[0080] The embodiment of the present invention further discloses an electric vehicle, including the traction control system of the electric vehicle.

[0081] The beneficial effects of the present invention are:

[0082] The present invention provides a traction control method and system for an electric vehicle, and the electric vehicle. When the electric vehicle is climbing a slope on an open road, current gear information, current wheel speed of a driving wheel, and current wheel speed of a non-driving wheel of the electric vehicle are obtained. If the current gear information is a forward gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of a motor is controlled to be the driving torque corresponding to the current vehicle speed. If the current gear information is a reverse gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the non-driving wheel, and it is judged whether the current vehicle speed is greater than a preset vehicle speed threshold. If so, the current driving torque of the motor is controlled to be 0 N·m; if not, the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed. This not only ensures the uphill performance in the forward gear, but also because when the electric vehicle is reversing on an open road, the current wheel speed of the non-driving wheels will be lower than the current wheel speed of the driving wheels. Therefore, the current vehicle speed determined based on the current wheel speed of the non-driving wheels will be lower than the current vehicle speed determined based on the current wheel speed of the driving wheels. This can effectively avoid or delay the torque limiting control of the current motor driving torque, thereby improving the uphill performance of the vehicle in reverse gear.

[0083] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above is a further detailed description of the present invention in conjunction with specific embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. Those skilled in the art may make various changes in form and details, including making several simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A traction control method for an electric vehicle, the electric vehicle comprising a driving wheel and a non-driving wheel, characterized in that: The traction control method comprises: The current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel of the electric vehicle when the electric vehicle is climbing a slope on a split road are obtained, the current vehicle speed of the electric vehicle is determined according to the current gear information, the current wheel speed of the driving wheel, and the current wheel speed of the non-driving wheel, and the current driving torque of the motor is controlled according to the current vehicle speed; wherein, If the current gear information is a forward gear, the current vehicle speed of the electric vehicle is determined according to the current wheel speed of the driving wheel, and the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed; If the current gear information is reverse gear, determining the current vehicle speed of the electric vehicle according to the current wheel speed of the non-driving wheel; and judging whether the current vehicle speed is greater than a preset vehicle speed threshold; If yes, the current driving torque of the motor is controlled to be 0 N·m; If not, the current driving torque of the motor is controlled to be the driving torque corresponding to the current vehicle speed.

2. The traction control method of an electric vehicle according to claim 1, characterized in that: The vehicle speed threshold is 30km / h.

3. The traction control method of an electric vehicle as claimed in claim 2, characterized in that: The current wheel speeds of the driving wheels include the current wheel speed of the left driving wheel and the current wheel speed of the right driving wheel.

4. The traction control method of an electric vehicle as claimed in claim 3, characterized in that: The current vehicle speed is determined according to the current wheel speed of the driving wheel by the following formula: Among them, v 车 is the current vehicle speed, v 左驱 is the current wheel speed of the left driving wheel, v 右驱 is the current wheel speed of the right driving wheel.

5. The traction control method of an electric vehicle as claimed in claim 4, characterized in that: The current wheel speeds of the non-driven wheels include the current wheel speed of the left non-driven wheel and the current wheel speed of the right non-driven wheel.

6. The traction control method of an electric vehicle as claimed in claim 5, characterized in that: The current vehicle speed is determined according to the current wheel speed of the non-driving wheel by the following formula: Among them, v 车 is the current vehicle speed, v 左非驱 is the current wheel speed of the left non-driven wheel, v 右非驱 is the current wheel speed of the right non-driven wheel.

7. A traction control system for an electric vehicle, characterized in that: Used to execute the traction control method of an electric vehicle according to any one of claims 1 to 6, the traction control system comprising a first controller, a second controller and a sensor; the second controller is connected to the first controller and the sensor respectively; in The first controller is used to obtain and send the current gear information of the electric vehicle when it is climbing the slope of the open road to the second controller, and the gear information includes forward gear and reverse gear; A sensor, used for detecting and sending the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel of the electric vehicle to the second controller; The second controller is used to receive the current gear information, the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel, and determine the current vehicle speed of the electric vehicle according to the current gear information, the current wheel speed of the driving wheel and the current wheel speed of the non-driving wheel, and control the current driving torque of the motor according to the current vehicle speed; Wherein, if the current gear information is a forward gear, the second controller determines the current vehicle speed of the electric vehicle according to the current wheel speed of the driving wheel, and controls the current driving torque of the motor to be the driving torque corresponding to the current vehicle speed; If the current gear information is reverse gear, the second controller determines the current vehicle speed of the electric vehicle according to the current wheel speed of the non-driving wheel, and determines whether the current vehicle speed is greater than a preset vehicle speed threshold; If yes, the second controller controls the current driving torque of the motor to be 0 N·m; If not, the second controller controls the current driving torque of the motor to be the driving torque corresponding to the current vehicle speed.

8. The traction control system of an electric vehicle as claimed in claim 7, characterized in that: The first controller is a vehicle controller, and the second controller is a traction controller.

9. The traction control system of an electric vehicle as claimed in claim 8, characterized in that: The sensor is a wheel speed sensor.

10. An electric vehicle, characterized in that: A traction control system for an electric vehicle comprising the steps of:

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