柔性并联机器人动力学特性的灵敏度分析

Sensitivity Analysis of Dynamics Characteristics of a Flexible Parallel Robot

为了获得精确的柔性并联机器人动力学特性的灵敏度分析结果,通过对柔性并联机器人动力学模型的分析,提出了基于微分法的动力学特性灵敏度分析方法,计算精度比差分法提高25%,计算时间缩短了86%。分析了柔性并联机器人动力学特性对各设计参数的灵敏度。柔性并联机器人的动力学特性对连架杆的截面积、构件集中质量及各杆件截面的厚度比较敏感。利用灵敏度微分法计算了设计参数发生微小变化后的动态响应值及固有频率值,在误差小于7%的情况下,计算时间缩短了95%。以3-RRR柔性平面并联机器人为例,说明微分法是准确、有效的。分析动力学特性灵敏度对柔性并联机器人的弹性动力综合和优化设计有重要意义。

To obtain the accurate sensitivity analysis results on the dynamics characteristics of a flexible parallel robot, we analyze its dynamics model and propose the dynamics characteristics sensitivity analysis method using the direct differential method. Compared with finite difference method, the calculation accuracy of our method increases 25% ; its computing time decreases 86%. We also analyze the sensitivity of the robot＇s dynamics characteristics to various design parameters. The analysis results show that the dynamics characteristics are sensitive to the cross-section area of framed links, lumped mass and the thickness of various links. Using the differential method, we compute the dynamic response value and natural frequency value of the robot after its design parameters slightly change. The computing time decreases 95% when the error is smaller than 7%. A 3-RRR flexible planar parallel robot illustrates that the differential method is accurate and effective. The sensitivity analysis of dynamics characteristics sheds light on the elastic-dynamic synthesis and optimal design of a flexible parallel robot.