三自由度Delta并联机械手轨迹规划方法

以三自由度Delta并联机械手为研究对象,针对其高速搬运作业下的操作空间和关节空间的轨迹规划策略进行研究。结合实际作业需求,对机械手末端运动轨迹的关键路径点进行设置,建立点到点的搬运作业轨迹。以机械手运动学逆解模型为基础,在操作空间利用3-4-5次多项式运动规律建立操作空间运动特征到关节空间运动特征的映射关系。以机械手运动学正解模型为基础,在关节空间利用五次非均匀有理B样条(NURBS)运动规律建立关节空间运动特征到操作空间运动特征的映射关系。在运动轨迹关键点位置及运动时间相同的条件下,对两种轨迹规划方法进行计算机仿真,对比分析机械手关节角度、角速度和角加速度等运动特征,并通过物理样机试验进行验证。结果表明关节空间内基于五次非均匀有理B样条运动规律的轨迹规划方法在减小运动过程中机械手振动和降低电动机功耗等方面优势明显。

Trajectory Planning of 3-DOF Delta Parallel Manipulator

Taking 3-DOF Delta parallel manipulator as the research object, different trajectory planning methods in operating and joint space under high-speed operations are researched. Combined with practical requirements, the motion trajectory of point to point is defined through a set of critical path points. In the operating space, based on the inverse kinematics model, the mapping relation of motion characteristics from operating space to joint space is established according to the 3-4-5 polynomial motion law. In the joint space, based on the forward kinematics model, the mapping relation of motion characteristics from joint space to operating space is established according to the quintic non-uniform rational B-spline (NURBS) motion law. Under same critical path points and time, simulations and analyses of movement characteristics (the position, velocity and acceleration of joint) on the two trajectory planning methods are proposed, and the comparison experiment is carried out. The results show that the trajectory planning method of quintic NURBS motion law in joint space has an obvious superiority in reduction of the vibration of the manipulator in movement and the motor power consumption.