Reseach Of Trajectory Tracking And Obstacle Avoidance Control For Autonomous Mobile Robot

As a typical nonholonomic control system, the research and development ofmobile robot is always a very active field.Taking nonholonomic autonomous mobilerobot as control plant,this paper conducts a reseach around trajectory trackingproblem with obstacle avoidance in unknown environment for mobile robot.To deal with the trajectory tracking control problem for nonholonomic mobilerobot,the implementation of control system combines the kinematic model anddynamic model in the paper.Firstly,Backstepping approach is used to design thekinematic controller，to achieve the control speed for tracking the reference trajectoryby reducing position tracking error.Then the improved computed torque method basedon Fuzzy Cerebeller model Articulation Controller(FCMAC) is used to design thedynamic controller.In particular,FCMAC was used to approximate the nonlinearitiesand uncertainties in mobile robot’s dynamic model,combined with the velocityerror,then a torque controller was constructed,in which a sliding item is used tocompensate the influence of uncertainty robust.The analysis of Lyapunov stabilitytheory ensures the tracking error converges asymptotically to zero,the MATLABsimulation results also verify the effectiveness and superiority of the control method.Specific to the obstacle avoidance problem in the process of mobile robot’strajectory tracking in unknown environment,under the premise of realizing mobilerobot’s tracking for reference trajectory,a double-loop control scheme based on theconcept of impedance control was proposed in this paper.Tracking control wasobtained in the main loop,when an obstacle is detected,the auxiliary loop will producea fictitious force,based on the sensor’s information and the impedance controlconcept,to adjust the desired position to revisionary location, and by compensatingthe reference velocity,the obstacle avoidance control is embedded into the trackingcontrol,realizing mobile robot’s automatic obstacle avoidance.The MATLABsimulation results validate effectiveness of trajectory tracking control and feasibilityof the obstacle avoidance method.Finally,hardware architecture and software structure based on Pioneer2DXplatform is designed to realize mobile robot’s trajectory tracking control withautomatic obstacle avoidance.Experimental results further verify the effectiveness andreal-time of the control strategy for trajectory tracking with obstacle avoidance.