Vertical Parking Strategy Based On Four-wheel Steering Vehicle

The automotive has been a hundred year of development since the date of its birth.which become a symbol of national industrial civilization. Today,automobile is not only simple body, chassis, engine and electric pile, it carries a lot of advanced electronic equipment. Intelligent and lightweight car is already irreversible direction, people get free from the simple boring driving behaviors, and enjoy the full of science and technology pleasure to the modern civilization. The main contents of this paper is based on the intelligent four-wheel steering, when the car gets close to the vertical parking space, and how to park the car in accordance with a pre-planned route.The subject bases on Four-wheel-steering model,setting up the simplified two degree of freedom dynamics model.Using mathematical formulas and geometric to get kinematics expression of the car.Simply explain the parking path planning.comparison of the neural network algorithm,genetic algorithm and fuzzy logic algorithm,determining the vertical parking strategy based on path planning, and distribution of the parking movement.The next,Setting up dynamics of four wheel steering vehicle.obtaining two degrees freedom expression of kinetics car,through giving vertical path planning of the car parking,In Matlab/Simulink simulation environment,giving a simple analysis of PID mechanism,I design a PID controller, fuzzy rule table, path planning simulation.the results show that the path planning tracking effect is better.Further,chosing the CPU for the car control selection,designing a hardware structure for the electronic control unit, which contains a power module, the motor drive control module, ultrasonic and infrared ranging module, a wireless communication module and CAN communication module,measuring the parking space information through sensors,then the control system send the control commands to the actuator of the car after processing,designing the circuit board of intelligent vehicle control center.Finally,I design the control system software of four wheel steering vehicle, the characteristics of μC / OS-Ⅱ operating system and the application of MCU are introduced. The main function module call flow diagram,flow chart of data acquisition of angle signal, speed signal acquisition part, motor control software design flow chart of different parts, compared with the different steering motor control method, due to the limited time and experimental conditions,only a part of a four-wheel car has been done experiment and developed hardware debug module. the most part of four wheel steering vehicle path planning vertical parking design have been completed.