The Design Of Control System And The Resarch Of Path Tracking Algorithm For Intelligent Vehicle

With the rapid development of automobile industry, car ownership is also growing, which caused traffic accidents, road congestion, environmental pollution and other phenomena has become even more serious. Researching about intelligent vehicle can avoid traffic accidents, improve traffic efficiency, improve traffic safety, and the new energy intelligent vehicles can save energy and ease air pollution and other issues.Intelligent vehicle is divided into three parts: environment observation, planning and control systems. Control system is the basis for intelligent vehicle to achieve unmanned. The accuracy of control system is the key and difficult in the field of intelligent vehicle. In this dissertation, we research the intelligent vehicle's speed control and path tracking, some achieved results are as follows.Firstly, we introduce the structure of BJUT-IV. Study the working principle of sensors installed in the vehicle, it is a foundation of information collection, multi-sensor fusion, intelligent vehicle's speed control and path tracking.Secondly, we design a strategy of speed control. The speed control system can be divided into lower control system and upper control system. Lower control system is using PID control method for controlling the motor control; Upper throttle control system is using PID control and Upper brake control system is using fuzzy control, according to the switching rules to control speed, this algorithm can effectively avoid frequent switching between the brake and the accelerator, reducing the loss of vehicle components, to ensure stability of the vehicle.Thirdly, according to the structure and working principle of EPS system, and combinning with the structural characteristics of BJUT-IV, we design the steering control system and establish the control strategy. The error of this system is small, and has good accuracy and rapidity. Based on the pure pursuit algorithm, we proposed a method for determining the point preview based on the geometric positional relationship, so that the path tracking process can quickly determine point preview. Designing a controller, which the controller parameters can be changed according to changes in the curvature of the planned path. Then, we establish a kinematic model of the vehicle, and simulation to verify the feasibility and accuracy of the algorithm.Finally, we write the BJUT-IV PC software in the Visual Studio 2008, the software uses UDP protocol to obtain data information from the data processing PC, and through the serial port to send control commands. In the campus road, we carried out the experiment, to verify the feasibility of the algorithm and the rationality of design scheme.