绳驱动并联机器人张力约束工作空间分析

Tension restrained workspace analysis for cable-driven parallel robot

绳驱动三自由度机器人可以实现空间的自由转动.由于绳索只可拉伸不可压缩的单向特性,研究驱动绳索张力对机器人的控制具有重要意义.运用几何和矩阵的方法可以分析绳索的张力分配情况;在存在张力约束的条件下,提出张力系数作为评价张力分配优劣状况的指标,通过计算可以得到张力系数分布图,从而对机器人工作空间有直观的认识,进而提出有效的张力优化算法;通过对最小预紧力影响因素及选取方法的讨论,可以得到动态最小预紧力实时计算公式,保证绳索时刻处于张紧状态;通过样机的力检测系统张力反馈的实验可以验证理论推导.通过对以上几部分的分析和研究,可以对四绳驱动三自由度机器人的张力问题有综合全面的认识.

Cable-driven 3-DOF（three degree-of-freedom）robot was free to rotate in the workspace.For the cable was unilateral which was only may be stretched but not be compressed.To control the robot better,it was significant to research the cable tension.By using the geometry and the matrix method,it was easy to analyze the assignment situation of cable tension.Under the density restraint＇s condition,tension coefficient was proposed as the appraisal of the tension assignment.After obtaining the tension coefficient distribution map,it had a direct-viewing understanding of tension workspace,then the effective tension assignment optimization algorithm can be proposed;By the discussion of the influencing factor and the selection method＇s of the smallest pre-tightened force,it may obtain the smallest real-time computation pre-tightened force formula,thus it would guarantee that the cable tension was at tightens in every condition;Finally,with the prototype＇s strength examination system the tension feedback experiment was taken,which may confirm the above theory.Through analyses and research of the above several parts,it may actuate a synthesis and comprehensive understanding for the cable tension problem of four cable-driven three degree-of-freedom robots.