The Structure Design And Development Of Three-DOF Active Rehabilitation Robot For Upper Limb

Nowadays, China is entering aging society, like European and American developed countries. The elderly people constitutes an increasingly large percentage of the country’s population. At the same time, stroke incidence has been rising. Vary degrees of hemiplegia would be happened on stroke patients after treatment. In addition, the number of patients with physical disabilities and hemiplegia caused by other factors is also increasing, which would place heavy burdens on families and the society. Timely scientific and effective stroke rehabilitation after treatment will greatly improve the efficiency of rehabilitation, making stoke patients recover motor function early. Therefor, it is very significant and valuable to do research on Upper Limb Rehabilitation Robots.At the understanding of the current situation of the development of Upper Limb Rehabilitation Robots at home and abroad, and combining the existing problems of rehabilitation robots, this paper proposes Three-DOF design for Upper Limb Rehabilitation Robots and carries on research and development. This paper focuses on the research and development of active mechanical structure design, the positive and inverse kinematics analysis of mechanical structures, and the inverse kinematics simulation. The Rehabilitation Robots researched in this paper has three degrees of freedom which has active pattern and passive pattern that realized by turning on and off of the computer-controlled magnetic powder clutch, and this two patterns can achieve space rehabilitation training not only by controlling the closed loop servo control system which can drive the patients’limbs, but also by operating end handle without external power source. The two movement patterns both use virtual reality technology, which by setting different interesting games at different difficult degree to stimulate patients’potential motion ideas and build good man-machine interaction environment. Patients’limbs should be felt the perception that the moving objects in a virtual environment bring to the patients, which can be achieved by the computer-controlled torque adjustable magnetic powder brake when at the passive movement pattern, and by computer-controlled torque adjustable magnetic powder clutch and AC servo motor when at the active pattern, such can improve the intelligent degree of the rehabilitation robots.By using the D-H method to establish coordinates for three-DOF Upper Limb Rehabilitation Robot and do kinematics analysis, can get Rehabilitation Robot inverse kinematics equation. Based on this, Jacobian matrix of Rehabilitation Robot can be deduced. The speed of robot end in space can be calculated by the Jacobian matrix if having the speed of robots joint. All this lay a theoretical foundation for robot motion control and trajectory planning. To establish three-dimension model of Rehabilitation Robot based on Robotics Toolbox in Matlab, and do inverse kinematics simulation, can verify the reasonableness of Rehabilitation Robot’s structural design from the joint angular displacement diagram and the terminal displacement diagram.This paper combines robotics and virtual reality technology, develops a three-DOF Upper Limb Rehabilitation Robot in which the active and passive movement pattern can be switched freely. The work this paper done will laid a solid theoretical basis for further program control and software development of the rehabilitation robots.