三自由度欠约束柔索驱动并联机器人的轨迹规划  

Trajectory Planning of a 3-DOF Under-constrained Cable-suspended Parallel Robot

作　　者：赵涛 何燕妮 高永航 李旺 王欢 ZHAO Tao;HE Yan-ni;GAO Yong-hang;LI Wang;WANG Huan(College of Mechatronic Engineering,North Minzu University,Yinchuan 750021,China)

机构地区：[1]北方民族大学机电工程学院,银川750021

出　　处：《科学技术与工程》2024年第19期8142-8149,共8页Science Technology and Engineering

基　　金：宁夏重点研发计划(引才专项)(2021BEB04029);北方民族大学中央高校基本科研业务费专项(2020KYQD39)。

摘　　要：柔索驱动并联机器人是一种特殊的并联机器人,属于柔性机器人的一类,它的末端执行器是由柔索代替刚性杆驱动实现其位姿的变化。研究了一种三自由度欠约束柔索驱动并联机器人,其索杆可以沿着圆形导轨旋转,即索杆夹角是可变的,实现机器人构型的可重构,减少柔索与柔索以及柔索与障碍物发生碰撞的概率。采用矢量闭环原理建立该机器人的逆运动学方程;根据拉格朗日公式建立该机器人的动力学方程;给定机器人末端执行器的运动轨迹,采用五次多项式进行规划,得出规划前后X、Y和Z方向的位移、速度和加速度曲线,在速度突变的点处,规划后的速度和加速度曲线实现光滑过渡,避免机器人在运动过程中发生振动和冲击,使得机器人末端执行器的运动轨迹平滑;三根柔索长度和拉力的实验曲线与规划后的期望曲线基本吻合,相机追踪轨迹与五次多项式规划后的运动轨迹基本一致;数值仿真和实验结果验证了三自由度欠约束柔索驱动并联机器人的逆运动学和动力学分析的正确性,以及五次多项式规划的有效性。Cable-suspended parallel robot is a special type of parallel robot that belongs to the category of flexible robots.The endeffector is driven by cables instead of rigid rods to achieve the change of its pose.A three-degree-of-freedom(3-DOF)underconstrained cable-suspended parallel robot was studied.The cable mast could rotate along a circular guide rail,that is,the angle of the cable mast is variable,which realizes the reconfiguration of the robot and reduces the probability of collision between cable and cable as well as between cable and obstacles.The inverse kinematics equation of the robot was established based on the vector closed-loop principle.The dynamics equation of the robot was established according to the Lagrange formula.Given the motion trajectory of the robot's end-effector,and the quintic polynomial was adopted to plan the motion trajectory of the robot.The unplanned and planned position,velocity and acceleration curves in the X,Y and Z directions were obtained.At the points where the velocity changed abruptly,the planned velocity and acceleration curves achieved smooth transition to avoid vibration and impact during the robot's movement,so as to smooth the motion trajectory of the end-effector.The experimental curves of the length and tension of three cables were basically consistent with the planned expected curves,and the camera tracking trajectory was basically consistent with the motion trajectory after the quintic polynomial planning.Numerical simulation and experimental results validated the correctness of the inverse kinematics and dynamics analysis of the 3-DOF under-constrained cable-suspended parallel robot,as well as the effectiveness of the quintic polynomial planning.

关 键 词：柔索驱动并联机器人 逆运动学分析 动力学分析 轨迹规划 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]