Research On Control Strategy Of Wheeled Robot Based On Sliding Mode Variable Structure

A rush of new study into traditional vehicles has been sparked by the advent of contemporary innovative technologies.Due to their simple structure,flexible movement and easy control,twowheeled robots have emerged as one of the key research directions in areas like unmanned driving.Among them,balancing control is not only an important part of two-wheeled robot control,but also an essential component in the field of control such as helicopter.Therefore,research on balance control strategies of two-wheeled robot is of great significance.This thesis focuses on a wheeled robot system based on a reaction wheel and analyzes its unique mechanical structure.The reaction wheel is used as the entry point for modeling and the robot model is simplified to an inverted pendulum model.The system dynamics equations are established using the momentum moment theorem to analyze forces on the simplified inverted pendulum model.In order to achieve high-precision balancing control of wheeled robots,the balancing controller is designed using a sliding mode control strategy.Two methods are designed to approximate the system disturbances: a finite time disturbance observation method and a Double Hidden Layer Recurrent Neural Network method(DHLRNN).The adaptive gain of the network center vector,base width,weights,and feedback parameters are designed based on the sliding mode variables and a fast nonsingular terminal sliding mode controller based on DHLRNN is designed.Meanwhile,for the phenomenon of fitting error at the early stage of DHLRNN fitting,a fuzzy control method is proposed to control the weight of DHLRNN interference observables and sliding mode control eigen-switching gain,and a fuzzy sliding mode controller based on DHLRNN is innovatively designed.The Lyapunov stability proof is performed for the designed controller,and the MATLAB environment is built to simulate and verify the controller.Finally,a real-world test platform of the wheeled robot based on the reaction wheel is built using the STM32 chip,attitude sensor MPU6050,display,and other hardware.Four different experimental scenarios are designed to fully verify the control performance of the controller.This thesis completes the research on the balance control strategy of two-wheeled robots at the levels of model building,balance controller design and stability proof,MATLAB simulation and system experiment,innovatively coupling DHLRNN,fuzzy control and sliding mode control together,and designing three sliding mode controllers.The simulation and experimental results demonstrate that the three controllers significantly improve the robustness of the wheeled robot system.In particular,the DHLRNN-based fuzzy sliding mode controller achieves the best control performance with the smallest control error.