Study On The Lower Limb Rehabilitation Robot Based On3-UPU Parallel Mechanism

With the aging trends of China increasingly serious, the number of older people isincreasing whose limbs flexibility get worse or even disabled during the physiologicalrecession. In addition, the people have also increased significantly who are nerve damage orlimb injury caused by war, industrial injury, traffic accident, disease, disaster or other reasons.But oppositely, the contradiction between rehabilitation equipment and the needs of patientshave become increasingly prominent: artificial nursing costs increase year by year; medicalrehabilitation equipment is single function and expensive. Therefore, the research anddevelopment of rehabilitation equipment for human limbs will have a good prospect.This paper studies on the lower limbs rehabilitative robot. Firstly, this papercomprehensively introduces the domestic and foreign research situation and the technicaldifficulties of the lower limbs rehabilitative robot. It plays an important guiding role in theconception and development for this subject. Secondly, it proposes the structure designobjective of lower limbs rehabilitative robot after understanding the structure characteristics,movement mechanism and damage mechanism of lower limbs. Thirdly, according to thestructure design objective, the degree of freedom and drive mode are determined. Andmechanisms are respectively designed for hip joint, knee joint and ankle joint, so the series iscomposed of the whole mechanism of human lower limb s rehabilitative robot model. Purerotational3-UPU spatial parallel mechanism has been adopted to implementation ofrehabilitation of hip joint and ankle joint. The DOF of this mechanism has been qualitativelycalculated based on screw theory. And the position and velocity of moving platform has beenanalyzed. The calculation results verify that this parallel mechanism has three rotational DOF,and the rotation axes intersect at one point. So it can be used to implement the three rotationalDOF of hip joint and ankle joint. Fourthly, according to the body size of the lower limbs, the3D model of lower limbs rehabilitative robot has been built by using the3D design softwareCreo. The3D model has been simplified in the3D design software Creo, then imported toMATLAB simulation mechanism Simulink and SimMechanics to establish the kinematicssimulation model of lower limbs rehabilitative robot. Through the simulation analysis, thefeasibility and correctness of the kinematic model have been proved, laying the foundation forthe dynamics analysis, structure optimization, gait planning and trajectory control. In the end,rehabilitation evaluation system of the lower limbs rehabilitative robot is studied. Combinefuzzy comprehensive evaluation and analytic hierarchy process (AHP-FCE evaluation method)to assess the lower limb rehabilitation, and evaluate the activity of the hip joint as example.The example proves that the AHP-FCE rehabilitation evaluation method is realized fully, obviously superior to the traditional clinical rehabilitation evaluation method, and providestechnical support to realize rehabilitation evaluation system of lower limb rehabilitationrobot.