Path Tracking Control An Unmanned Research Vehicle

With the rapid changes and development of science and technology, Autonomous Land Vehicle(ALV) begin to enter people’s vision. ALV is a typical of four-wheeled mobile robot, is a multi-disciplinary, involving a wide range of technologies. ALV technology for enhancing national security has a direct sense, and at the same time directly related to the promotion of mobile robot technology. Currently ALV’s technology has gradually begun to people’s lives, such as safe driving assistant system to reduce traffic accidents and has a strong sense of real-world applications.In this paper, studying the path tracking control system of ALV, based on actual road conditions, and designing a path tracking control system to improve the robustness and adaptability of it. The main contents of this paper have the following five sections:First, introduce the project background and significance of it, describe in detail the current research achievement of the domestic and abroad, and the key technology for unmanned vehicles involved in a detailed overview and commonly used methods. Analyze the movement control problems.Secondly, making the unmanned vehicle "cruiser" as the research platform, introduces its architecture and details of its several components, such as perception systems, planning systems, decision systems, control systems and actuators, applying the mathematical knowledge to describe path tracking control problem, introducing component of the motion control system; concluded the problem of the vehicle in the road to face reality, and thus also to this article problems.Third, this chapter studies the related content about ALV’s speed control method, design and implements a PID speed control system. Describe summarily the unmanned vehicle speed control problem, and concluded the goals. According to the strong nonlinear vehicle susceptible to environmental factors and characteristics, combined with the experience of humans to control vehicle speed control, describes the rules and adjust parameters of PID control principle, design the PID speed controller rules, through the continuous test and adjust PID parameters, complete the design and debugging of the speed controller. Experiments verify the effectiveness, accuracy and robustness of the speed control system, overcome the vehicle’s own complex nonlinear problems and interference by the external environment.Fourth, this chapter studies the related content about ALV’s steer control method, design and implements a steer control system. Use the advantages of "preview-follow" theory and pure-pursuit algorithm, combining the advantages of fuzzy control, design and implement the parameters self-tuning fuzzy controller, the input are the current speed and the heading error, output is the look ahead distance, and then using pure pursuit to calculate the front-wheel planning angle, so that the vehicle can follow the preplanning path in actual road driving, solve the inaccurate of mathematical control models bring uncertainty control.Finally, test the path tracking control system using the platform "crusier" in real road environments. The results demonstrate the effectiveness, robustness and reliability of the proposed control system, and the method are summarized and discussed.