Research On Intelligent Parking Assist Control System Based On Ultrasonic Detection Technology

With the increasing of urban population, reduction of parking spaces, the size of each parking space tending to be smaller, the study of intelligent parking assist has become increasingly necessary. It can reduce parking accidents in the small parking spaces, save time, and improve driving comfort index. It can also alleviate traffic congestion when the parking time is too long.The main goal of this paper research is to design a better robustness and performance parking control system that allows the car to automatically stop into smaller compact parallel parking. First, this paper introduces the geometry and kinematics model during car reversing the process and based on the two models combined Ackerman angle and assuming the car parallel with parking in starting point and end point, determine the double arc tangent reversing the path of the car in the maximum situation, and the minimum parking size is determined by the basic parameters of the car. Subsequently, the parking system hardware and software were designed, and including the ultrasonic ranging module whose circuits were designed including ultrasonic receives, amplifies, and frequency-selective filter circuit by Protel and simulated to verify the parameters of electronic components by multisim, and the software of ultrasonic ranging system was designed to achieve functions of distance measurement and communication with the host computer. Finally, the incremental PID control scheme based on path planning and adaptive fuzzy control is researched by MATLAB software; analysis of the reasons for selecting incremental PID and using the given step signal debug PID controller parameters to determine the optimal PID parameters, and then through the path tracking to determine the minimum parking spaces; the fuzzy controller was designed including the input and output variables, the appropriate variable dimensions and control rules. By simulation results, the paper analyzes the advantages and defects of PID control and fuzzy control. In the last, the membership function of fuzzy control was optimized by Genetic Algorithms.By distance range and accuracy experiments, the ultrasonic ranging system can meet the requirements of the system; in order to achieve better results, the paper analyzed the measurement data to analyze its intrinsic and extrinsic detection error and obtained the error correction equation by software analysis.By simulation results, in two control schemes, the adaptive fuzzy control scheme is better than the incremental PID control. Its the minimum parking size is 1.37 times of vehicle length, and the starting point for reversing and reversing speed have a certain degree of tolerance. The fuzzy controller performance is further improved by optimization of the use of genetic algorithms.