辅助运动索驱并联机器人方案设计与动力学分析  

Design and Dynamics Analysis of Auxiliary Motion Cable Drive Parallel Robot

作　　者：赵振军 臧雨晴 章杰 ZHAO Zhenjun;ZANG Yuqing;ZHANG Jie(School of Mechanical and Material Engineering North China University of Technology,Beijing 100041,China)

机构地区：[1]北方工业大学机械与材料工程学院,北京100041

出　　处：《机械设计与制造》2024年第12期1-9,共9页Machinery Design & Manufacture

基　　金：国家自然科学基金青年科学基金(11702294)。

摘　　要：高龄化导致的脑卒中运动功能障碍患者需要借助于康复机构等进行辅助康复训练。设计一种辅助运动障碍患者从卧位到站立位基础姿态运动的四索驱并联机器人机构,利用电机驱动绞盘控制绳索伸长缩短辅助人体实现基础姿态的运动,绞盘缠绕处为钢丝绳,钢丝绳下端连接橡皮绳分别牵引在辅助人体运动的关键节点处。对机构进行运动学分析,求解索长与牵引点位置坐标的雅克比矩阵,并对绳索牵引人体达到坐立位、站立位运动过程人体运动角度及角速度进行预定规划。为了考虑橡皮绳弹性的动力学影响,基于拉格朗日动力学进行系统动力学建模,并利用Simulink开展动力学仿真,分析机构牵引人体运动过程中起卧角度、角速度及膝盖屈直角度、角速度的变化规律。在系统动力学模型基础上,应用非线性前馈补偿的PID控制方法对绳索收放长度进行控制,使绳索牵引人体安全、平缓地达到期望轨迹及期望速度,确保人体的舒适性,并利用Lyapunov方法证明控制系统的稳定性。针对有无重力补偿项、柔索变刚度和人体不同质量参数等因素对系统动力学影响进行了仿真,通过对比分析验证了弹性绳作为执行机构的必要性及控制律设计的有效性和稳定性。Stroke patients with motor dysfunction caused by aging need auxiliary rehabilitation training with the help of rehabilitation institutions.A four-cable-driven parallel robot mechanism is designed to assist the basic posture movement of patients with dyskinesia from lying position to standing position.The winch driven by motor is used to control the elongation and shortening of rope,and assist the human body to realize the movement of basic posture.The winding part of the winch is a steel wire rope,and the lower end of the steel wire rope is connected with a rubber rope,whichx is respectively pulled at the key nodes of assisting human movement.Through analyzing the kinematics of the mechanism,the Jacobian matrix between the cable length and the position coordinates of the traction point is solved,and the human motion angle and angular velocity are planned in the process of rope traction to the sitting and standing position.Considering the elasticity of rubber rope,the system dynamics modeling is derived based on Lagrange dynamics,and the dynamic simulation is carried out by Simulink.The simulation results obtain the variation laws of rise and lie angle,angular velocity,knee flexion angle and angular velocity in the process of human body traction.The PID control method of nonlinear feedforward compensation is applied to control the retraction and retraction length of the rope,so that the rope can safely and smoothly reach the desired trajectory and speed,ensure the comfort of the human body,and prove the stability of the control system by Lyapunov method.The effects of gravity compensation,variable stiffness of flexible cable and different mass parameters of human body on system dynamics are simulated.Through comparative analysis,it verifies that necessity of elastic rope as actuator and the effectiveness and stability of control law design.

关 键 词：柔索并联机器人 运动学分析 动力学分析 运动仿真 前馈PID控制 

分 类 号：TH16[机械工程—机械制造及自动化] TH113[理学—运筹学与控制论] TB114.2[理学—概率论与数理统计]