Electric vehicle automatic parking system based on vehicle speed and torque control

Abstract

The invention discloses an automatic parking system of an electric vehicle based on vehicle speed torque control. In an automatic parking process of the electric vehicle, in addition to using calculated real-time basic torque Tbase to control motor output torque Tmot of the electric vehicle to ensure that the electric vehicle can run under actual environmental conditions in accordance with a preset automatic parking trajectory and a real-time target vehicle speed vset, the system is also in accordance with four state control whether to increase a calibration value of incremental torque deltaTon the basis of the real-time base torque Tbase as the motor output torque Tmot of the electric vehicle, that is, the calibration value of the incremental torque deltaT is increased in a calculation state, and the incremental torque deltaT is taken as zero in a ready state, a lock state and a termination state. Therefore, through the utilization of the introduction method of the incremental torquedeltaT in the automatic parking process, the system can greatly reduce the initial moment impact of the electric vehicle in the start and the climbing motion of automatic parking, eliminates the shaking of the electric vehicle in the automatic parking process, and improves the comfort of the automatic parking.

Description

technical field [0001] The invention relates to an electric vehicle automatic parking system based on vehicle speed and torque control, which is applied to the electric vehicle. Background technique [0002] At present, most of the automatic parking systems of electric vehicles use PID controllers for motor torque control. PID controllers are proportional-integral-differential control systems, which are widely used in industrial control. [0003] However, there are inherent problems in the PID controller. In the PID control system, the output torque of the motor is generally adjusted by means of the actual vehicle speed. Considering a large number of nonlinear states in vehicle operation, some designs use positional PID, integral separation PID, fuzzy PID algorithm, etc., which can only partially optimize the control system. [0004] Because the parameter adjustment of the PID controller requires a lot of time and manpower, and it is easy to cause system oscillation and mak...

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Problems solved by technology

[0004] Because the parameter adjustment of the PID controller requires a lot of time and manpower, and it is easy to cause system oscillation and make the system unstable and crash under non-simulation conditions.

In addition, the response time of the PID controller is slow, which is not suitable for the intelligent vehicle control system that requires fast response, and the parameter adjustment is difficult.

Finally, the application of PID control in automatic parking has the situation of motor torque output jitter, that is, the fixed torque output by PID will give a sudden excitation to the vehicle, which will cause jitter during vehicle operation and affect the comfort of the vehicle.

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