Kinematics Research On Externally Bone Robot For Rehabilitation

In recent years, the population aging in our country is increasingly serious,the obvious physiological decline during the aging process is lower limbs flexibility in the elderly,and a variety of adverse ininfluence in daily life.In addition,the movement disorders of patients that caused by a disease such as stroke are also increased significantly,in contrast,the rehabilitation therapy through the manual or simple medical equipment, has been far from being able to meet the patient’s requirement.With the development of national economy, this special group has received more and more attention.The technology and quality of these products are also improved accordingly that treatment,rehabilitation and service for them.Therefore, the research and application of rehabilitation equipment that services for limbs has broad development prospects.Firstly, the structure and parameters of the exoskeleton rehabilitation robot that designed by the research group were introduced in this paper.Based on the structure and parameters of the robot,using the D-H parameter method to establish the kinematic model of the robot,and then the positive and inverse kinematics solution were carried out.The robot’s inverse kinematics algorithm was verified and analyzed, and the correctness of the kinematics algorithm was obtained. The working space of the robot is simulated and analyzed based on Robotics toolbox, which provides a theoretical reference for the trajectory planning of the robot.Secondly, the differential kinematics of robot is analyzed and researched.The jacobian matrix is established to express the relations of the angular velocity of joint space and end-effector’s linear velocity in Cartesian space.Based on the rehabilitation robot kinematics transform matrix,the vector product method is adopted to solve the jacobian matrix which relative to the base coordinate system,and the inverse jacobian matrix is calculated. Based on the jacobian matrix, the linear velocity and angular velocity of the end-effector of the rehabilitation robot are derived.Thirdly, based on the robotics toolbox in MATLAB, the joint space trajectory planning of the rehabilitation robot was carried out, and the motion parameters of each joint were obtained. According to the characteristics of the application of rehabilitation robot, in order to meet the characteristics of functional rehabilitation of upper limb,based on the interpolation algorithm to establish the rehabilitation trajectory of space straight line and circular arc,and the corresponding motion parameters of joint space are obtained by simulation calculation. It provides a theoretical basis for the motion control of the robot. Selected the six degrees of freedom exoskeleton rehabilitation robot from Swiss Hocoma,then choose the same space straight line and circular arc trajectory as the6-DOF rehabilitation robot, and carries on the simulation calculation. Through the analysis and comparison, the rationality of the selected degree of freedom of the designed rehabilitation robot is verified.Finally,the simulation model of the rehabilitation robot is established based on SimMechanics, the torque simulation is carried out, and the simulation results are analyzed and researched.It provides a theoretical reference for the motion control of the robot.