The Dynamics Modeling And Simulation Of Ankle-rehabilitation Parallel Robot

In this paper, a highly flexible ankle-rehabilitation parallel robot with three adjustable structure parameters is studied. The kinematic performance, dynamic performance, finite element analysis and structure optimization of the parallel robot are selectively analyzed. The main contributions in this thesis are listed as follows:Firstly, The structural characteristics of ankle-rehabilitation parallel robot were analyzed. Then based on RPY(Roll-Pitch-Yaw) method, the inverse kinematic model of the parallel robot was created. After that, the kinematic performance curves under the given structural parameters were drawn out in Matlab software. According to the performance curves, the constraction length of the four pneumatic muscles in the original state was designed. Meanwhile, using the inverse kinematic model of the ankle-rehabilitation robot to educe the Jacobian matrix which is the foundation of the dynamic analysis.Secondly, The expression of kinetic energy and potential energy of the motion part of the ankle-rehabilitation parallel robot were educed. Combining with the Jacobian matrix, the dynamic model of the robot is established based on the second kind of Lagrange equation method. Then, the dynamic performance curves under the given structural parameters were drawn out in Matlab. After that, a dynamic simulation platform and its human-computer interface which can output the kinematic and dynamic performance curves depending on the different inputs including three adjustable mechanical structural param eters and 14 kinds of rehabilitation exercise were built in Matlab.At last, In order to get the stress and deformation of the ankle-rehabilitation parallel robot when the pneumatic muscles offered their max forces, the simplified prototype of the robot was created by using the three-dementional modeling software solidworks and exported to the finite element analysis software ANSYSworkbench. By applying of the ANSYSworkbench, the stress and deformation cloud pictures when the pneumatic muscles offered their max forces were carried out. Then the three structural parameters and the structural style of the moving part of the robot were optimized. What's more, the results of the optimization were verified one by one in workbench. The optimal scheme increase the strength and stiffness of the robot greatly, making its max stress and deformation during the rehabilitation exercise into permissible range.