Research On The Predictive Control Algorithm Of Trajectory Tracking For Upper-limb Rehabilitation Robot

With the coming of the aging society,the number of stroke patients is increasing rapidly.Most stroke patients have clinical symptoms of hemiplegia.Rehabilitation training,which is used in stroke patients with Rehabilitation training robot,can not only restore the injured brains,but also overcome many disadvantages of traditional rehabilitation therapy,and make rehabilitation training process more efficient.In the studies of existing upper-limb rehabilitation robots,most of the executive layer controllers use PID control.For the strongly coupled and strongly nonlinear upper-limb rehabilitation robot system,there are problems of weak anti-interference ability and high requirement for model precision.In this thesis,a 5-DOF upper-limb rehabilitation robot is selected as the research object.In view of the above problem,the predictive control theory is applied to the trajectory tracking control,and the method of dynamic linearization in the model free adaptive control theory is applied to improve it.Firstly the structure and model of the five degree of freedom upper limb rehabilitation robot are studied,and the kinematics model and dynamics model are derived.Secondly the design method of predictive controller based on linearization of the upper-limb rehabilitation robot is given.The predictive control algorithm of the upper limb rehabilitation robot is studied by using the discrete linear dynamic model as predictive model.And then the predictive controller is presented.Then the predictive control algorithm is improved combined with the model free adaptive control method.And the overall model free adaptive predictive control scheme of the upper-limb rehabilitation robot is given.The dynamic linearization method is used to obtain the discrete dynamic linearization model of the human-computer interaction system of the upper limb rehabilitation robot.The model is used as a predictive model of predictive control.The estimation algorithm and the prediction algorithm of parameter matrix are derived and the optimal rolling optimization control law is presented.And then the stability of this algorithm is verified.Finally the MATLAB/Simulink toolbox is applied to simulate the different control methods of the upper-limb rehabilitation robot under ideal state and disturb state respectively,which verifies their feasibility and effectiveness.And the comparison shows that the improved model free adaptive predictive control algorithm has higher control accuracy and strong anti-interference ability.