Research On Multi-segment Parallel Parking Trajectory Planning Based On B-spline

The number of cars in my country is huge and continues to grow rapidly,and parking-related accidents occur frequently in crowded traffic environments.Therefore,automatic parking technology has become a hot issue in intelligent driving technology research.Parking path planning is one of the key technologies of the automatic parking system.Research at home and abroad shows that the effect of automatic parking path planning affects the probability of parking success and parking accuracy.In this paper,the differential flat theory is introduced on the basis of B-spline parking trajectory to reduce the calculation difficulty,and the convolution of B-spline endpoints is solved by using a convolution curve,and the parking starting area analysis method is explored to improve the parking flexibility.The main research contents and conclusions of this article are as follows:1.First,the obstacle avoidance and non-integrity constraints of the vehicle during parking are analyzed;the concept of differential flatness is introduced,and the vehicle is proved to be a differential flat system.Subsequently,the concept of B-spline theory is introduced,and the differential flat output B-spline of the vehicle is parameterized,and the trajectory planning becomes the optimization of the position of the spline control point.2.The choice of parking starting point affects the success of parking trajectory planning.Combining the obstacle avoidance and non-integrity constraints of the vehicle,this paper studies the starting area of the vehicle at zero heading angle and the starting area and starting heading angle range when the vehicle starts parking at multiple heading angles,and then gives Selection method of optimal parking starting position and optimal starting heading angle.3.Finally,the fuzzy theory and PID theory are introduced,and the advantages brought by the fuzzy theory for PID parameter adjustment are analyzed.Combined with the driver preview model,the lateral error and the heading angle error are fused,and a reasonable membership function and fuzzy rules are set in the fuzzy controller.Simulink-carsim joint simulation study under the same fuzzy PID controller,the vehicle has multiple segments Difference between the parallel parking trajectory and the traditional double-arc parking trajectory tracking effect.The simulation results verify that the lateral error,heading angle deviation and parking end point error are smaller when tracking the multi-segment trajectory in this paper...