Research And Application Of Fully Domestic Automatic Parking Assist System Based On Ultrasonic Sensor

With the development of the automotive industry and the advancement of sensor technology,the intelligence of automobiles has been further improved and applied.APA(Auto Parking Assist)is an important feature of the Advanced Driver Assistant System,which can enhance the driver’s driving experience and solve many problems during the parking process.It has a wide market space and commercial value in the future.This paper focuses on the control algorithm and the architecture of the software and hardware for the automatic parking system.The research content includes four parts: the design of the parking control algorithm,the design of the hardware controller,the design of the software framework and the system test on the vehicle.Firstly,the algorithm of the parking control process was designed,which mainly included two parts,one is the processing of environmental data and the other is the control strategy.The environmental information is obtained based on the ultrasonic radar,including the data processing of ultrasonic radar.The parking control strategy mainly includes horizontal parking path planning based on reverse path segmentation planning method,one-step/multi-step vertical parking entry path planning based on different scenarios,exit path planni ng,and path tracking control based on open-loop angle feedforward and PID composite control.Secondly,the APA controller hardware was designed by the TONG XIN MICRO’S THA6 x chip.The driver of the circuit,the peripheral signal transmission and the voltage detection module of the main control chip,and ultrasonic radar driver module were designed,achieving information exchange between the main control chip,sensors,and other external signals.After that,the application layer,the basic software layer,and the MCAL driver layer of the system software architecture were designed.The functions of each software module were defined and the interaction logic,dependency relationships,software workflow diagrams between different modules were designed.Memory space allocation was also carried out to ensure the efficient and reliable execution of the software system.Finally,based on the design architecture of software and hardware,the function tests of horizontal and vertical parking were conducted on a Chery car.The test results showed that the success rate of the automatic parking system based on ultrasonic sensors designed in this paper was as high as 98.2%,and the probability of achieving an ideal parking posture was about 80.7%.The final parking position and the distance between the front and rear vehicles were within a reasonable range,which can meet the application requirements of the automatic parking system.