The Balance Control Of A Wearable Parallel Weight Bearing Walking Assist Robot And Development Of A Portable Controller

Our country has entered an era of aging society, and one of the common diseases of old people is osteoarthritis. Pain and dysfunction caused by osteoarthritis will lead to trouble while walking. In this paper, development of wearable parallel walking assist robot has been put forward to provide the elderly with weight bearing walking assist and rehabilitation training during the process of walking.The author of this paper analyzed the current the developments on walking assist devices both at home and abroad, most of them are big in size, heavy in weight, very expensive difficult to maintain walking balance, and unable to walk outdoors. So it’s necessary to study the walking balance control of walking assist robot, and develop a portable controller.The preliminary work of this study is introduced at the beginning of the paper. Then as the improving designs for the mechanical system of the robot, are introduced mainly including the lock mechanism of self-locking slide rail and a new design of shoes with sensor inside. The paper also introduces the electrical system of the walking assist robot, including system composition, circuit diagram of electric system and pneumatic schematic diagram.The balance control principle of walking assist robot is studied. On the basis of static walking theory the study calculates the center of pressure of the shoes and the support force of all the cylinders by segmenting human’s walking cycles and adopted the support state method and proportion coefficient method to calculate the power cylinder support force. The control system of walking assist robot is introduced in detail. The hardware design includes the LPC1768processor of ARM Cortex-M3, the smallest system and the peripheral interface circuit. While the software design includes modular programming, and the human-computer interaction interface. Eventually the power portable controller of the walking assist robot has been developed.It the simulation analysis of walking assist robot has been carried out by Matlab and Simulink software. The ground reaction force model, the human body model and walking assist robot model are set up finally the man-machine integration model is obtained. Through the body data acquisition experiments on walking, the author collected12degrees of freedom drive vector of human body. Through the simulation analysis on walking process, the human body model confirmed the authenticity of human walking gait stability and the ground reaction force model. The simulation analysis on man-machine integration model of walking assist power confirmed that the walking assist robot can assist people in achieving weight bearing walking assist and some certain effects on maintaining gait balance; Proportional coefficient method of control principle is proposed, which can realize a steady walking gait balance of man-machine integration model.The author at last carried out the outdoor walking assist experiment in different control methods and under different weight bearing level by using the experimental prototype. The experimental process and experimental results are also described in detail. The stability of the mechanical system, the rationality of the principle of balance control, the quickness and accuracy of the simulation analysis of portable controller is verified by the experiment.