Rehabilitation Robot Trajectory Control Considering Load Disturbance

Aging problem is increasingly serious in China.Lower limb function disorder of old people is one of the problems to be solved.The omni-directional lower limb rehabilitation training robot trajectory tracking problem of patients were studied.The omnidirectional lower-limb rehabilitation robot has problems of strongly coupled and complex nonlinear system with lots of uncertainties.Frictional force,the rapid changing of controller output and interaction between the patient and robot affect the robot motion accuracy.The disturbance is uncertain when the robot help patient move.Therefore,it affects the accuracy of control seriously.The motion control to deal with the disturbance of human has become an important issue in the field of rehabilitation robot.The following aspects are included in this thesis:(1)Mathematical model of the omnidirectional lower-limb rehabilitation robot was established. After that,the dynamics model of the omnidirectional robot with considering the disturbance force of patient have been analyzed. The structure of the omnidirectional robot has been analyzed.Two situation of the robot have been considered,respectively the ideal situation without load,the situation with consideration of disturbance produced by patient.(2)Interference of patients in training is very complicated and difficult to detect. This thesis take the dynamic model of omnidirectional robot as reserch object, the disturbance produced by patient is considered as the unknown and time-varying interference.An 2L robust controller was proposed by backstepping in order to solve this issue. The stability of the robust controller has been testified by Lyapunov theorem and HJI inequality.(3)A virtual model of rehabilitation robot through SimMechanics and Simulink 3D Animation toolboxes was built. SolidWorks mechanical model of the robot and parameters in SimMechanics robot dynamic model were described. Dynamics simulation was conducted.At last, the virtual omni-directional lower limb rehabilitation training robot trajectory tracking test platform was developed, and simulation research based on this model for the robust controller was conducted.The effectiveness of the proposed design method through comparing with conventional PI controller design method was verified. Aimed at designing controller this thesis is to improve the effect of rehabilitation exercise training by patients random disturbance force, play a small role for the development of the lower limb rehabilitation robot.