Research On Speed Tracking Control Strategy In Mobile Automatic Driving

In term of the nonlinear complex motion process of speed tracking control in automatic driving which is interference by some uncertain factors such as environment and whose object model changing real-timely, it is impossible to reach the tracking target relied on the traditional control strategy to regulating speed.Fuzzy control is a method of intelligence decision which need not know the precise math model of control object, and its idea imitate people's thinking decision to control the object of complex model or having strong uncertainty based on the fuzzy set theory, fuzzy language parameter and fuzzy logic reasoning. In fact, fuzzy control design the controller through collecting, finishing and analyzing the heuristic rules and people experience (fuzzy IF-THEN rules), which is fundamentally different to the traditional control method of beginning from controlling object's math model to designing controller for the object model. So, implementation tracking control to the speed used the fuzzy control method is a feasible solution to the speed control of moving mobile.This thesis design a fuzzy self-adaptive controller used in the speed tracking control in automatic driving combined with self-adaptive control theory. This controller is a combinational controller of fuzzy control and PID control, which realize the target of speed tracking through regulating three parameters'increasing value of the PID controller to realize auto regulation of PID parameters used fuzzy reasoning. Simulation experiment shows that this algorithm has the advantage of fast and self-adaptability, but can be easily interference by the environment.It can overcome the disadvantage by improving the fuzzy PID controller used the feedback mechanism of immunology system. Improved immunology PID fuzzy control algorithm make the controller have stronger self-adaptive function through fuzzy immunology self-adaptive regulation to the major controller's coefficient variation of proportional link. Simulation experiment shows that the immunology PID fuzzy controller effectively combined with fuzzy control, immunology feedback mechanism and PID regulation not only make the speed tracking process have strong self-adaptive quality and robustness to adapt variety quickly, but also greatly improve stable and dynamic ability in speed tracking, and the quality of speed control.