Exoskeletal The Elderly Assisted Walking Device Design,

Aging of the population is growing since 21st century. More attentions, which concerned with how to improve their quality of life, are paid to the elder people in the society. By applying exoskeleton technique which is a novel human motion-assistant robotics into walking-assistant field for elder person, it will improve the function of their lower limbs, and will also be a new research field. Although the research have been carried out for many years in Europe, America, Japan and other developed countries, the products are either expensive or in laboratory stage. Therefore, it is necessary to develop an exoskeleton device for elderly walking assistance, which is simple in structure, practical in functions and adapt to the national conditions.In this paper, a theoretical analysis and experimental research was completed about the exoskeleton device for elderly walking assistance. The walking mechanism of human was analyzed first. A kinematics model was completed; and the motion curve in walking was derived by video acquisition method. The hip and knee kinetic curve is obtained through dynamic analysis which is conducted in ADAMS simulation environment. Based on the above work, the working principle is established for the walking-assistant device.Then, a prototype is designed corresponding to the working principle including actuator selection, freedom arrangement, man-machine overlapping design of the elderly walking-assistant device. In order to satisfy the requirement in real-time and sensor signal matching for control algorithms, TMS320LF2407 is chosen as the central controller for the walking-assistant device, and a bipolar type H bridge driving circuit is designed according to the central controller. An experimental platform was constructed by employing top-below machine working style, which facilitate the following experiment research.On this basis, a novel control method which is called SAC force servo hybrid method is presented according to the principle of providing the right amount of aided torque at right time. This control method can switch between SAC control method and aided servo control method according to the judgment about the hip rotation speed. Consequently, the walking-assistant device is able to follow human movement in low speed, while realize an auxiliary torque output in the rest of the time.Finally, the tracking experiment of human walking and walk assistant experiment are presented to show the effectiveness and feasibility of SAC force servo hybrid control methods in the prototype.