Performance And Analysis Of 4-UPS/CU Ankle Rehabilitation Parallel Mechanism

Ankle is a very important joint in human body,which maintains people’s body balance.There are countless examples of ankle injury in daily life.Therefore,the research on ankle rehabilitation institutions is of great significance,which can provide effective rehabilitation measures for people with ankle injury.Starting from the structure of the human ankle joint and the movement mode of the ankle joint,this paper designed a 4-UPS/CU ankle rehabilitation parallel mechanism,which can meet all the movement modes of the ankle joint,namely adduction/abduction,varus/valgus,dorsal extension/toe flexion.The most important thing is that the rotation center of the institution is not only a little,but also can be adjusted with the different heights of the crowd,and the true sense of human-machine communion is achieved.Computing the number of DOF of a mechanism,helix theory concludes that the parallel mechanism 4-UPS/CU has four degrees of freedom,that is,the degree of freedom of rotation around the axes X,Y,Z and Z,and calculates the degree of freedom of the organ according to the advanced Kurzbach-Gruberle formula,and the result is the same as the number of degrees of freedom sought by the spiral theory means.Next,the positional inverse solution of the mechanism is solved,the experiment is a method of converting the angle to the hare euler and the closed detector method.The system has the correct response solution ger experiment to be the particle group optimization algorithm（PSO）.The system is obtained by the primary speed difference method of giacobian myatrics.Finally,the system is resolved by the work space matlab software,and the results show that the working space of the institution is continuous and uninterrupted,and the range is large,which can be used in ankle rehabilitation in the medical field.Adams simulation software was used to perform positive kinematic simulation of adduction/abduction,varus/valgus,dorsal extension/toe flexion of the 4-UPS/CU ankle rehabilitation parallel mechanism,and the curves of displacement,speed,angle and other curves of the parallel mechanism movement platform were obtained,and the analysis showed that the rotation angle of the three movements of the mechanism was within the maximum rotation angle of the human ankle joint.Next,an opposite kinematic simulate of the balanced mechanism is performed,and the curve diagram of the drive branch chain displacement of the three movements of adduction/abduction,inversion/valgus,and dorsal extension/toe flexion was obtained,and the phenomenon of stuck or urgent stop was obtained when the branch chain of the mechanism moved,indicating the stability of the operation of the mechanism.The consistency of the positive and negative kinematic simulation of the mechanism also verifies the accuracy of the simulation of the mechanism.Static analysis of the mechanism,way used by the resolve means,the equilibrium equation set of the mechanism is received,and then the mechanism is statically simulated.And the consequences show that the mechanism has a high transport capacity.The parallel mechanism is then dynamically analyzed,using the Lagrangian equivalent,to bring a dynamic equation and analyze the form of the mechanism to detect space.In the first or fourth order of the resonance of the mechanism,the analysis of the harmonic reaction of the mechanism is finally obtained and the displacement curve of the harmonic reaction of the mechanism is obtained,which is of great importance for the resonance of the research institution.