Research On Tremor Suppression Robot And Key Techniques For Pathological Tremor

With the development of the robotic technology, robot has been used widely in the field of medical treatment and healing. The research of rehabilitation robot has been developed quickly with conspicuous outcome, then solving many problems existed in traditional medicine. The research of medical robot might be regarded at present as one of the most fruitful and fast growing areas in robotics. The pathological tremor occur in human upper limb usually, though tremor is not life-threatening, but it can be responsible for discommodity of patients'daily life and even make that patients could not take care of theirself. Nowadays, there is no method which could cure tremor completely in medicine . The robot technology is applied to suppress patients tremor and make patients own the proper ability of self-care, so one effective solving method is supplied to improve the situation of lacking the method with curing tremor completely in medicine currently.After in-depth research on the mechanical features of human manus tremor, researchers have given the view that hunman upper limb with tremor could be treated as the second order biomechanical system, which muslce torque as input and upper limb position as output. The system respond to external incitation could be changed with the change of system damping, so the effect of supressing tremor could be obtained through changing patients damping by the tremor suppression robot..Based on the analysis of human upper limb biomechanical modle and human engineering, the tremor suppression robot with exoskeleton structure is developed. The robot has two degrees of freedom and could suppress the tremor existing during the motion of elbow flexion/extension and forearm rotation. The structure of measure part and tremor suppression part separated with each other is adoptted during the design of robotic elbow, so the tremor information could be measured through the angular displacement sensor taking advantage of human nonrigid body characteristic. The robot will interact with human body directly during working, and the security must be considered, so inactive device is chosen to supply suppressing tremor torque. Magnetorheological damper owning superior controllable characteristic and it is suitable for the tremor suppression robot. New rotary magnetorheological damper is designed with the characteristic of short magnetic circuit, few magnetic leakage flux, large working area and better heat elimination, so bigger damping torque could be applied with less cubage and power dissipation. The robot controller based on ARM is developed, the controller realizing the transform and process of tremor information, running of tremor supression control algorithm, the output of controlled quantity and so on.Based on the structure characteristics of the magnetorheological damper designed, the magnet circuit of magnetorheological damper is desinged with traditional magnet circuit design method, then initial structure parameters of magnetorheological damper are worked out. Based on the results, finite element analysis of magnetorheological damper mechanics performance is realized, 3-D structure model of damper is bulit using ANSYS parameter design language. Consider of the characteristic that magnetorheological fluid and magnetic core material own different non-linear permance character, the finite element model of damper is built with edge-based Solid117 element, then the 3-D static non-linear electromagnetic analysis is performed and performance parameters of the damper is obtained. Finishing the performance analysis, the optimization design of magnetorheological damper is carryed out. Then the magnetorheological damper is developed and the mechanics performance of the magnetorheological damper is tested.Human body is nonrigid, so the connection of the human limb and the tremor suppression robot is nonrigid, the flexibility deformation always exists during the process of interaction between human body and tremor suppression robot, and the deformation quantity of human limb can denote the information of max human body tremor torque. Fuzzy neural network merges the advantages of fuzzy system and neural network, fuzzy neural network controller has better validity for error control through learning. But the change of the maximum tremor torque will change the expected output value of the controlled object, and the fuzzy neural network controller controll effect will be influenced by the change of the expected output value. For improving above problem, two different error quantization method is adopted, so the tremor information can be measured through the flexibility deformation, and the influence of the the deformation change to the fuzzy neural network controller is avoided at the same time. For get the new expected output value of the controlled object, the gradual approach desired value control is used. During tremor supression control, fuzzy neural network control is used as main control method and gradual approach desired value control is used as aid, then ideal tremor supression effect can be obtained.The mechanism simulating human body tremor is developed, and it can supply tremor platform for robotic supressing tremor experiment. The testing result denotes that human tremor simulation mechanism can simulate the process of human tremor. Finally, the robotic supressing tremor experiment is implemented, experiment results denote that the tremor suppression robot has developed can suppress tremor effectively.