Trajectory Tracking And Autonomous Obstacle Avoidance Research Of Wheeled Mobile Robot

The motion control system of the wheeled mobile robot has the characteristics of nonlinearity,multiple input and multiple output,and coupling underdrive,and its motion control problem is more difficult.When the wheeled mobile robot works in a complex and unknown environment,it will be affected by many uncertain disturbances.Because the control of the two-wheel differential wheel mobile robot is simple and flexible,the complexity of the research is small.More and more domestic and foreign researchers have conducted research on it.In this paper,we study a two-wheel differential drive wheeled mobile robot,which mainly studies trajectory tracking and autonomous obstacle avoidance control technology,including:(1)The speed control performance of the two-wheel differential drive wheeled mobile robot affects the performance of trajectory tracking control and autonomous obstacle avoidance control.According to the forward speed and steering angular speed control coupling problem,a speed static decoupling matrix is ??introduced to reduce the coupling between forward speed and steering speed.Then the dynamic decoupling controller based on linear auto disturbance rejection(LADRC)is designed to combine the coupling term and The internal and external disturbances of the system are observed as total disturbances and feedback compensation,and the decoupling and anti-interference control of the speed of the mobile robot is realized.(2)Aiming at the trajectory tracking problem of wheeled mobile robot,a new trajectory tracking controller based on Lyapunov direct method is proposed.The stability of the method is proved by Lyapunov direct method theory.By separately analyzing the stability of each error state variable in the tracking error model,the method designs the forward speed and steering speed control law of the trajectory tracking control,which can make the state variables of the trajectory tracking error model converge to zero.The control law has The dynamic change of the reference speed has little influence on the tracking effect,and the control law is simple,the parameters are easy to be set,and the engineering is easy to realize.(3)Autonomous obstacle avoidance controller based on fuzzy theory is designed for the autonomous obstacle avoidance problem in the trajectory tracking process of wheeled mobile robot.The distance information of the obstacle and the position information of the target point are blurred as the input of the controller.It enables the robot to move around the obstacle autonomously toward the target point.Then,based on the new trajectory tracking controller,a tracking and obstacle avoidance weighted decision system based on obstacle information is proposed to ensure that the robot is as close as possible to the reference trajectory curve during the obstacle avoidance process.Finally,a dynamic reference trajectory generation method based on adaptive gravitation is proposed for the problem of excessive distance of reference robot in robot obstacle avoidance process.(4)This paper independently designed a two-wheel differential wheel mobile robot motion control system based on STM32.The robot uses multiple ultrasonic sensors to detect obstacle information.This paper designs a series of experiments on the system to verify the above.The reliability and practicability of the design method of wheeled mobile robot trajectory tracking and autonomous obstacle avoidance problems.