Mobile Robot Trajectory Tracking Based On Variable Gain PID Control

With the advent of the era of artificial intelligence,the research of mobile robot technology is more and more favored by people,involving all walks of life,such as industry,agriculture,service industry,national defense and so on.The wheeled mobile robot improves the human lifestyle and has the advantages of improving work efficiency and reducing labor intensity.Achieving precise motion control of a wheeled mobile robot is the most basic requirement to complete all robot work,and trajectory tracking control of a wheeled mobile robot is an important part of the motion control.Aiming at the problems of uncertain factors and system disturbances in wheeled mobile robot trajectory tracking control,this dissertation designs a mobile robot trajectory tracking controller based on variable gain PID control.The main research work of this dissertation is as follows:(1)Under the ideal condition that the wheels of the mobile robot do not slip,based on the kinematics model and dynamic model of the mobile robot,a fuzzy PID trajectory tracking control method based on variable gain is proposed.First,the conventional PID control is divided into a combination of PI and PD,and the output of the PID controller is converted into the sum of the error and the error change rate.Then,the fuzzy control method is used to design the gain that changes with the error,so that the mobile robot can track the desired motion trajectory.Finally,the effectiveness of the proposed method is verified by simulation and experiments.(2)Under the ideal condition that the wheels of the mobile robot do not slip,and considering the disturbance of the robot during its operation,an adaptive PI control method based on variable gain is designed.The proportional gain and integral gain of this method are composed of two parts,one is a constant,and the other one is to design adaptive adjustment law and adjust in real time.It is proved that this method can guarantee that all signals of the closed-loop system are bounded,and the actual trajectory of the mobile robot can gradually converge to the desired trajectory.The validity of the design is verified by simulation and experiments.