Research On The Rehabilitation Massage Robotic Arm Control System

Chinese massage with a long history is an effective mean for the treatment of senile body disease such as waist pain and Joint inflammation. Rehabilitation massage robot is a kind of service robot. Chinese massage robot platform is built on the base of traditional Chinese massage theory, and combines with the characteristics of high precision, accurate controllable massage strength, action repeat accurately and never fatigue of the robot. Rehabilitation massage robot arm is an important part of rehabilitation massage robot. The arm adopts four degrees of freedom series form. The advantages and disadvantages of the control system decide if the end actuators of the rehabilitation massage robot could transmit smoothly and position accurately. And that relations to the massage effect directly. The control system of rehabilitation massage robot arm is a key technology of it.Based on analyzing the working mechanism of rehabilitation massage robot arm deeply, the paper analyzes the work space of robot arm by using MATLAB software firstly, makes PC+PMAC controller as control core of the robot arm, Copley digital servo drive and Maxon brushless dc servo motor are its drive unit, the hardware control platform of the arm is designed and built, and debugged perfectly.Secondly, D-h coordinate system of the arm is established, founds the dynamics model of the arm through Lagrange function balance method, finds out the output torque of joint motors, then, calculates the instantaneous transfer function of joint motor and verifies it by using Kirchhoff s law and Torque balance equations.Thirdly, establishes three of the closed-loop system control model of single joint motor, calculates the optimal PID parameters values of the system parameter equation quickly based on Genetic algorithm and the instantaneous transfer function of the arm. The values are used to quadratic curve fitting by the least square method. The functional equations of each joint angle and the PID parameters are got. The paper puts forward the "one step ahead" least square algorithm, so as to increase the convergence speed of the parameter estimation. And the PID parameters of the control system realize auto tuning. Use of MATLAB software, mechanical and electronic hybrid simulation analysis of the arm is studied.Finally, the control system software of the arm is developed. The experimental data shows that the position repeat precision of the robotic arm and the operation after force could meet the technical requirements of the rehabilitation massage robot.