基于力阻抗模型的上肢康复机器人交互控制系统设计

Design of interactive control system for upper limb rehabilitation robot based on force impedance model

摘要:

传统上肢康复机器人交互控制系统受到奇异位形影响，导致系统控制精准度较低，为此提出基于力阻抗模型的上肢康复机器人交互控制系统。设计上肢康复机器人交互控制系统结构，选取双串口12CSA60S2系列单片机作为下位机控制核心模块，利用椎齿轮改变驱动力方向，设计机械臂肘部结构，通过同步带传动，将器件隐藏于空手柄中。设计机械臂腕部结构，满足临床康复时上肢患者站姿与坐姿训练需求。选择箔式应变片BF350力传感器，设计电阻应变片桥接电路，处理传输信号。构建机器人目标阻抗模型，设计基于力阻抗控制策略，调节位置、速度和关节。为改善奇异位形情况，在奇异位形附近关节角速度指令直接由各个关节力矩阻尼控制得到，实现角速度精准输出，完成系统控制。由实验结果可知，该系统直线运动位置、旋转关节位置和伸缩关节位置跟踪结果与标准值基本一致，满足系统设计需求。

Abstract:

Traditional interactive control system of upper limb rehabilitation robot is affected by singular configuration, which leads to low control accuracy. Therefore, an interactive control system of upper limb rehabilitation robot based on force impedance model is proposed. The structure of the interactive control system of the upper limb rehabilitation robot is designed. The dual serial port 12csa60s2 series single-chip microcomputer is selected as the control core module of the lower machine. The elbow structure of the manipulator is designed by changing the driving force direction with the vertebral gear. The device is hidden in the empty handle through the synchronous belt transmission. The arm wrist structure was designed to meet the needs of standing and sitting posture training of upper limb patients in clinical rehabilitation. The foil type strain gauge bf350 force sensor is selected, and the resistance strain gauge bridge circuit is designed to process the transmission signal. The target impedance model of the robot is constructed, and the control strategy based on force impedance is designed to adjust the position, speed and joint. In order to improve the singular configuration, the joint angular velocity command near the singular configuration is directly obtained by the torque damping control of each joint to realize the accurate output of angular velocity and complete the system control. The experimental results show that the tracking results of linear motion position, rotation joint position and telescopic joint position are basically consistent with the standard value, which meets the system design requirements.