Research And Application Of Adaptive Fault- Tolerant PID Trajectory Tracking Algorithm For Wheeled Robot

Wheeled mobile robot is a kind of under-actuated non-linear system with nonholonomic constraints and multiple inputs and multiple outputs.Its motion control problem is challenging.Because of its flexible structure,wheeled mobile robots have been widely used in various fields(such as industry,agriculture,military,etc.).The application of these fields means that the working environment of wheeled mobile robots is becoming more and more complex and vulnerable to the influence of external environment.In some workplaces of mobile robots,there are icing and wet sliding phenomena on the road,which bring challenges to the motion control of mobile robots.In addition,there are inevitably friction and collision problems in the actuator hardware in the actual system,which will lead to less than 100% efficiency of the actuator or some uncontrollable parts in the actuator,while some special working environment such as cold and low temperature will aggravate the above phenomenon.Therefore,it is of great significance to study the trajectory tracking problem of wheeled mobile robots under the above circumstances.Based on the dynamic model of the two-wheel differential mobile robot,an adaptive fault-tolerant PID trajectory tracking algorithm is designed and applied to the snow-sweeping robot.The main contents of this paper are as follows:(1)Based on the dynamic model of the two-wheel differential mobile robot,considering the factors of slip and actuator failure,an adaptive fault-tolerant PID trajectory tracking algorithm is designed.The simulation results show that the adaptive fault-tolerant PID trajectory tracking algorithm is effective compared with the traditional PID controller.(2)According to the functional requirements of the snow-sweeping robot,the hardware system of the whole controller is divided into subsystems according to the different functions,and the selection of related devices is completed according to the functions and requirements of each subsystem.(3)According to the actual application scenario of snow-sweeping robot,path planning strategy is designed,obstacle avoidance strategy is designed according to the distribution and type of obstacles,and judgment process is designed to improve the accuracy of obstacle detection,aiming at the problem of obstacle misjudgment easily occurring in ultrasonic sensor.Finally,the track tracking field test is carried out on the snow-sweeping robot.