Abstract:

Automatic Parking System is an important part of intelligent vehicle research. Most of the current vertical automatic parking algorithms fail to consider the influence of the heading angle error of the initial postion of the vehicle， which leads to unsatisfactory parking or scratch as a result. For this problem， the vertical parking path planning and path tracking algorithms， when the heading angle of the initial position of the vehicle has error （i.e. the initial position heading angle is not zero）， are studied in this paper. Firstly， the quadric spline function is applied to plan the parking path to improve the path characteristics. Then， a path tracking control algorithm combining preview error feedforward and heading angle feedback is designed in this paper， in order to improve the performance of the current commonly used preview error feedforward tracking algorithm， which shows big error and obvious lag in variable curvature path tracking. The proposed parking algorithm is verified by Simulink/Carsim co?simulation and real vehicle test. Both the simulation and real vehicle test results indicate that when the initial position heading angle of the vehicle is not zero， the designed algorithm is able to plan a feasible parking path， while the path tracking control algorithm combining preview error feedforward and heading angle feedback has smaller tracking error and better final parking position， comparing with that just using preview error feedforward.

Key words: automatic parking, vertical parking, path planning, path tracking, heading angle feedback