一种平面二自由度并联机器人速度性能与运动学参数关系研究

Study of the Relationship Between Velocity Performance and Kinematics Parameters of a Planar Two Degree-of-freedom Parallel Manipulator

以一种平面二自由度并联机器人为研究对象,在已有机构的基础上,对其进行了改进,提出了一种具有较小运动惯量且可实现运动平台平动的新型平面二自由度并联机器人机构。不同于已有的研究方法,综合考虑了机器人的输入和机构尺寸作为机器人运动学参数,应用空间模型理论建立了机器人机构的设计空间。在设计空间内计算机器人全域速度性能指标,绘制了机器人速度性能图谱,在此基础上探讨了机器人速度性能与运动学参数之间的关系。结果表明:速度极小值η_(vmin)和速度极大值η_(vmax)随r_1的增大而减小,即r_1越小,速度性能越好;随r_2的增大而增大,即r_2越大,速度性能越好;在0<r_1≤1.5且0.7≤r_2<1.5的区域内η_(vmax)和η_(vmin)值较大,机器人具有很好的速度性能。速度性能图谱有助于该机器人机构的性能评价与优化设计。

Based on the existing mechanisms,a new kind of two degree-of-freedom planar parallel manipulator with planar translational motion and small inertia was improved and taken as the object of study. Unlike the traditional study method,not only the geometric parameters but also the input of the manipulator are consider as the kinematics parameters,and the design space was obtained by utilizing the theory of geometric model of the solution space. The global velocity indices were calculated in the design space,the velocity atlases of the manipulator were plotted,and the relationship between the velocity and the kinematics parameters of the manipulator was discussed. The results show that: the minimum and maximum velocity indexes η_(vmin)and η_(vmax)are inverse to r_1,that is r_1 is shorter,the velocity performance is better; The η_(vmin)and η_(vmax)are proportional to r_2,that is r_2 is longer,the velocity performance is better;While 0 < r_1≤1. 5 and 0. 7≤r_2< 1. 5,the velocity performance of the parallel manipulator is better. The atlases are very useful for performance evaluation and optimum design of the manipulator.