Research On Adaptive Trajectory Tracking Control Method For Two-Wheel Self-Balanced Mobile Robot

Two-wheeled self-balancing mobile robot(TSMR)has wide application in home services,intelligent transportation,industrial production,due to its advantages of flexible steering,dynamic balance,lightweight structure,and environmental protection.Traj ectory tracking control is a vital technology of the motion control for TSMR,which is the basis for its efficient autonomous motion and performing corresponding tasks.Meanwhile,TSMR is a typical underactuated system,which makes the trajectory tracking control of TSMR extremely challenging.Therefore,this paper launches the research of adaptive trajectory tracking control method for TSMR based on its kinematics and dynamics model.The main research works are as follows:(1)According to the position of TSMR in the coordinate system,the kinematics model of TSMR is constructed,and the time derivative of TSMR position error can be obtained.By using the Newton-Euler method to analyze the forces on TSMR,the dynamics model of TSMR is established,which provides a reliable model basis for the design of adaptive trajectory tracking controller of TSMR.(2)To realize the attitude trajectory tracking control of TSMR,an adaptive sliding mode attitude control scheme based on radial basis neural network(RBFNN)is proposed for TSMR with external disturbances and unmodeled dynamics.According to the tilt angle dynamics model of TSMR,a hyperbolic tangent function based sliding mode controller is developed.Then,a RBFNN approximator is designed to eliminate the interference of unmodeled dynamics on the tilt angle dynamics model of TSMR.Furthermore,the minimum parameter learning method(MPLM)is introduced to reduce the calculation of RBFNN weights.Finally,the tracking capability of the devised control strategy is verified by MATLAB/Simulink simulation.(3)To achieve attitude,longitudinal and steering trajectory tracking control of TSMR,an adaptive trajectory tracking control strategy with prescribed and predictive performance is designed.Based on the dynamics model of TSMR,the design of prescribed performance function(PPF)and the transformation of trajectory tracking errors are completed.Then,an adaptive trajectory controller with prescribed and predictive performance is developed for TSMR system,which can enable TSMR to achieve trajectory tracking under external disturbances and constrain the tracking errors of TSMR within the PPF bounds.Furthermore,RBFNN is introduced to compensate the unmodeled dynamics of TSMR.Finally,the efficacy and accuracy of the devised adaptive trajectory control strategy is verified in MATLAB/Simulink.(4)Based on the kinematic and dynamic models of TSMR,an adaptive full-state constrained tracking control strategy is proposed to realize the trajectory tracking control of TSMR with safety constraints.First,the hierarchical control structure of TSMR is constructed.Second,a velocity planner is designed to realize the kinematic tracking control of the TSMR system.Then,by combining the unified barrier function and dynamic surface control method,an adaptive fullstate constrained tracking controller of TSMR is constructed.Finally,the robustness and security of the adaptive full-state constrained tracking control strategy are verified by using MATLAB/Simulink platform.