Research On Mechanism Of Multifunctional Walking Assistance Robot

In China, some parts of the old people rely on wheelchair instead of walking besidesmost people with physical disability. For disabled people and the old people, it is easy toresult in complications, such as pressure sores, lower limbs osteoporosis, muscle atrophy andso on, due to long-term using wheelchair. Even it can be dangerous for living. At present, inmany nursing homes, communities, hospitals and so on, have established specialized activityplaces to do rehabilitation training for the disabled and the elderly. However, there is lack ofequipments to train people standing or walking from their wheelchair to standing posture.Therefore, it is urgent to have multifunctional rehabilitation devices which are of stand framefunction and passive training function for lower limbs under the conditions of sitting position,standing position and walking. The main function of walking assistance rehabilitative robot isto provide intelligent auxiliary walking for users, and to maintain and even strengthen theirability to walk, so that they do not need be supported by others and can walk safety andindependently. So it is not a tool which is instead of their walking. To compare with thetraditional intelligence walking assistance devices, its functions are more plenty, safe andcomfort. So the research of the rehabilitation robot that can help the elderly and the disabledto rehabilitation training, is of great significance to promote the development of rehabilitationmedicine in our country.The research work of this dissertation is supported by the major project of national hightechnology development program (863program), whose name is multifunctional walkingassistance rehabilitative robot (2008aa040203). In order to solve some key problems, whichare existed in the standing-up training and walking assistance training, it is need to know howto use walking assistance rehabilitative robot to help the elderly themselves with no ability towalk. So theoretical analysis and experimental study are done deeply in the following aspects.There are mechanism scheme and drive control scheme of walking assistance robot, motionplanning of walking assistance mechanism, analysis of standing-up mechanism, and thedynamics of man-machine system in the process of walking assistance.The research present situations of the domestic and foreign walking assistancerehabilitative robot and related fields are summarized. The mechanism, drive mode andworking principle are analyzed and compared. According to the rehabilitation medical theory,the structure option of one kind of passive walking assistance robot is presented. Thecharacteristics of mechanism and its working principle are described. And the drive controlscheme of robot is designed. The prototype of multifunctional walking assistancerehabilitative robot is produced as well.According to the experimental measurement of human walking gait information and the training requirement of walking assistance, it is need to optimize the parameters of walkingassistance mechanism. The positive and inverse kinematics of walking assistance mechanismis analyzed and the corresponding kinematics models are established by using D-H method.The kinematics simulation model of walking assistance mechanism is set up by usingsimulation module of the mechanism simulation toolkit SimMechanics. And the validation ofkinematics analysis of walking assistance mechanism is tested and verified. Then the workingspace of walking assistance mechanism is got. And the coordinate motion planning andsimulation analysis of the both sides of the walking assistance mechanism are finished.The kinematics analysis of the people’s standing procedure is done by using D-H method.And the motion trail of buttocks in the process of standing is got. Based on SimMechanics,kinematics and dynamics simulation models of standing-up mechanism are set up. And theinfluence of drive torque, which is caused by spring to standing-up mechanism at differentusing conditions, is analyzed. According to the simulation results, it can prove that the motionlaw of the end of sit up mechanism is basically coincided with the motion law of buttocks inthe process of standing. So it can be used to simulate the process of standing about normalpeople.In order to study lower limbs and mechanical property of walking assistance mechanism,the model of them are established respectively. The generalized force is solved by usingvirtual work principle. And the dynamics equation of lower limbs and walking assistancemechanism are established by using Lagrange method. The man-machine system dynamicsmodel is set up on the bases of joint constraint method. The influence on drive performance ofsystem is analyzed, which is caused by different weight of people, different steps, anddifferent gait cycle. So, it can provide theoretical basis for the choice of motor and controlstrategy on walking assistance mechanism.The prototype of multifunctional walking assistance rehabilitation robot is produced. Themanufacture procedure of robot and its practical application are also introduced. The relatedexperimental research are done by using dSPACE platform, such as motor performanceexperiments, standing-up mechanism experiments and walking assistance mechanismexperiments. Through the results of experiments, it can prove that the rehabilitation trainingof standing-up and walking assistance can be carried out under the auxiliary ofmultifunctional walking assistance robot. So it can give many kinds of rehabilitation trainingservices to lower limbs patients and weak elderly.