Method for controlling traction of electric vehicle

Abstract

The invention discloses a method for controlling the traction of an electric vehicle. A motor is driven by one controller; and the controller is internally provided with a finished vehicle status gain calculator, a vector controller, an error observer and an optimal slip ratio tracker. When a system operates, the finished vehicle status gain calculator analyzes the intention of a driver according to initialized vehicle information and real-time read finished vehicle status information and determines a torque gain curve, a vehicle acceleration curve and a vehicle desired speed; then the vector controller controls the motor to be up to a preset torque; next, the error observer compares the error between an actual value and a calculated value of the speed and adjusts a road condition resistance coefficient; and the optimal slip ratio tracker calculates the real-time slip ratio of the vehicle and adjusts a slip coefficient in a torque equation according to the calculated value so that the vehicle keeps in an optimal slip ratio state. By using the method, the phenomenon of slip is effectively prevented, and the acceleration performance and the side stability of the electric vehicle are improved.

Description

technical field [0001] The invention relates to a traction force control method suitable for two-wheel drive / four-wheel drive electric vehicles, which belongs to the technical field of automobiles. Background technique [0002] The traction force of an electric vehicle is provided by its drive motor. One of the main characteristics of the motor that distinguishes it from the engine is fast torque response, high torque control accuracy, and the ability to calculate the actual torque through current feedback. The existing electric vehicle control system uses the motor as an actuator, and the power demand of the system is given by the vehicle controller or analog sensors. This control method cannot effectively use the characteristics of the fast power response of the motor. When driving and the motor torque is large, it is easy to slip, so that the adhesion of the vehicle cannot be used to the greatest extent (referring to the limit value of the tangential force of the road on ...

AI Technical Summary

Problems solved by technology

The existing electric vehicle control system uses the motor as an actuator, and the power demand of the system is given by the vehicle controller or analog sensors. This control method cannot effectively use the characteristics of the fast response of the motor power. When driving and the motor torque is large, it is very easy to slip, so that the adhesion of the vehicle cannot be used to the greatest extent (referring to the limit value of the tangential force of the road on the tire), which not only reduces the acceleration performance of the vehicle, but also It seriously affects the lateral stability of the car and poses a threat to the safe driving of the vehicle

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