The Research On Motion Control Of Mobile Robot With Nonholonomic Constraint

As humans explore the unknown field more and more frequently,mobile robots with nonholonomic constraint are playing more and more important role.Due to the uncertainty of the robot's own mass,size,rotational inertia and other parameters,and the robot will be subject to various disturbance imposed by the external environment,so human-controlled robots will encounter various difficulties when tracking specified trajectory.This thesis takes mobile robot with nonholonomic constraint as the research object,explores trajectory tracking in uncertain environments.The main contents are as follows:According to the wheel-ground shear mechanism,the relationship between motor torque and motion acceleration of mobile robot with nonholonomic constraint is established.And the rolling obstruction coefficient and ground turning obstruction torque plus various unknown disturbances are considered.A dynamic model of mobile robot with nonholonomic constraint is established.Aiming dynamic model for nonholonomically constrained mobile robots with uncertain disturbance,robust H? controller is established.The Riccati equation satisfying the stability relationship of the tracking error system is obtained.Then the stability of the system is deduced through Lyapunov method,and the performance index is satisfied.The simulation results verify that both the displacement tracking error and the velocity tracking error meet the specified performance indexes.This design method is effective.On this basis,the observer is designed basing on the rate of variation of the external disturbance and the second derivative of that.A novel controller with automatic gain adjustment function is designed based on the non-fragile control method.The Lyapunov method is applied to verify the stability of the tracking error system,and the tracking errors converge to a small neighborhood of the origin.The stability condition of the tracking error system is established,and the expression of the controller is obtained by solving LMI.Numerical simulation verifies the effectiveness of the design method.