The Research And Design Of Parallel Parking Control System Based On Path Planning

The increasingly congested city lane and the worsening parking environment has brought the huge challenge for the drivers parking. As a result, more and more experts and scholars have devoted to the research and development of the APS(Automatic Parking System).Trying to propose their safe, accurate, fast solutions, combined with the research of vehicle kinematics and the technology on electronic control, which could automatically control the vehicle parking into predetermined spaces. Consequently, reducing the probability of collision accident for the driver’s parking would be possible. Relying on the project fund--‘The research on the key technology of APS(Automatic Parking System) in the process of industrialization’, from Suzhou Automotive Research Institute, Tsinghua University, this paper discussed the condition of parallel parking on the three core issues of automatic parking system: path planning, acquisition and processing of sensor data and vehicle control, based on the test vehicle-- DongFeng Jing Yi X5.The purpose of this study was to design and develop an automatic parking controller, which could realize the function of parking the car into the reasonable parking spaces.This paper mainly completed the following work:First of all, according to the theory of Ackermann steering geometry to analysis the detail in the process of vehicle movement, the proper coordinate system had been established. Through the steering experiment to determine the steering gear ratio between the steering wheel and the wheel, the relation between real-time turning radius and steering wheel angle was gotten, which subsequently laid the foundation for the steering control.Secondly, the geometric relationship in the parallel parking process had been deduced, the minimum radius of the inverse method which was easy to implement in engineering had been proposed.This method was used for the planning of parking path. At the same time, on the basis of the method, the arc line method and repeated type parking method had been analyzed and simulated to verify the feasibility of the simple. The simulation results showed that parking the car into position could be realized in two methods. The repeated parking method could reduce the size of the parking space to a certain extent. Considering the constraints of vehicle, the spline function had been used to optimize the planning path, which solved the problem of tangent point curvature’s discontinuousness.Thirdly, according to the demand of parking control software and the rational allocation of system resources, the positive development for each software module and control algorithm was used to design a complete software implementation. As the experimental platform for parking vehicles, Jing Yi X5 was developed by the method of the two methods could realize the embedded development based on Infineon 16 bit microcontroller XC164CS16F20 F. Finally, the parking control system was designed which could realize the communication through the CAN bus combined with OBD interface. After a series of installation and debugging, steering intervention could be realized by the system.Finally, the platform of ultrasonic system had been built, using LABVIEW to design the sensor location display interface which can dynamically display the distance information in real time. Through the experiments of different speed and distance measurement of parking spaces, the error was analyzed. The measurement of parking space was done under different speed and distance, coming with the analyzes of the error. At the same time, with many experiments on parking control system, the reliability and stability of parking system has been verified. The results showed that the car could be parked into the space around 7m with the minimum radius method and arc line method in high success rate. Then, there is a brief analysis of existing parking problems, which gave rise to the coming of improvement measures.