基于区间分析的一类三转动自由度并联机构的精度设计(邀请论文)

面向大型结构件调姿、天线跟踪及快速定位等应用需求,研究三转动自由度并联机构3-PSUS的精度设计方法.首先,利用螺旋理论建立该机构的误差映射模型,并将影响机构末端姿态精度的几何误差分离为可补偿误差与不可补偿误差2类.其次,借助区间分析理论,提出不可补偿误差的灵敏度指标,并通过全域灵敏度分析揭示各项不可补偿误差对机构末端姿态精度的影响规律.然后,以灵敏度指标值为分配权重,建立各项不可补偿误差的优化分配模型,在给定精度约束下,借助遗传算法将难以实现的不可补偿误差的公差值松弛至最大可行区间.最后,通过蒙特卡洛仿真验证了所提出精度设计方法的有效性.

Interval Analysis Based Accuracy Design of a 3-DOF Rotational Parallel Mechanism ( Invited Paper)

The accuracy design of a parallel mechanism with three rotational degrees of freedom was studied, which might find its applications in large components pose-adjusting, satellite antenna tracking and high-speed positioning. Firstly, an error model of the mechanism was established by means of the screw theory, in which the compensable and non-compensable errors associated with parts were separated effectively. In the light of interval analysis theory, an appropriate sensitivity index was proposed and utilized for evaluating the influences of non-compensable errors with respect to pose errors of the moving platform. Based upon the sensitivity index, an accuracy synthesis problem subject to accuracy constraints was solved by genetic algorithms, whose objective was to maximize feasible intervals of design variables, ie, the non-compensable errors. Finally, the accuracy design method was validated through the Monte Carlo simulation.