Intelligent Parking Systemfor Four Wheel Steering Vehicle

The increasing vehicle ownerships result into that the traffic jam and vehiclecongestion, on the roads in great city, are getting worse. There always are vehiclecollisions in parking process. The tight and limited road space while vehicle turning andreversing requires much more mobility, flexibility and initiative collision avoidanceability of the automobile at the same time. Therefore, it is important to research anddevelop the intelligent four wheel steering automobile parking system especially.Firstly, based on automatic parking control system of four-wheel steering modelvehicle development, the main hardware architecture design of this system, includingDSP master control unit, motor-driven units, ultrasonic and infrared distance measuringsensor signal processing circuit, signals transmission module and interface circuits forwireless communications are elaborated. It is available to perceived externalenvironment information by the complement work between ultrasonic and infrareddistance measuring sensor, so that the parking space information is obtained accurately.Then the four wheel steering vehicle is studied according on the fields ofkinematics and dynamics. The two-degree-freedom dynamic model and kinematicsmodel of intelligent parking system (including body yaw motion angle, centroid lateralangle, front-wheel/rear-wheel steering angle) are established.Finally, after summarizing the traditional parallel parking strategy based on trackplanning. The track generating method integrating the differential flat and B-splinetheory is proposed to ensure the flat and smooth output of the four-wheel steeringvehicle. Then, a parallel parking space generating method with preventing collisionconstraints is put forward when the different constraints are analyzed minutelycombined with various automobile collision conditions during the parking process.The simulation results dedicate that the track generated by this method can both avoidautomobile parking obstacles effectively and overcome the halt turn problems inparking process.