摘要并联机构由于具有结构简单和高刚度等优点，被大量应用于工程领域，该文针对风洞天平校准台6-DOF（degree of freedom）并联复位机构进行精度分析。利用D-H（Denavit-Hartenberg）方法分析每条支链运动传递过程，建立包含铰链制造误差的RRRPRR支链运动学模型。利用Qusai-Newton法分析不同结构参数下铰链制造误差对加载中心精度的影响规律。研究结果表明：加载中心精度与铰链偏移误差处于同一数量级，且呈线性关系；为降低铰链偏移误差对加载中心精度的影响，在满足设计要求的前提下，应选择较小定平台和较大动平台、较小平台铰链夹角以及较大的平台间距离。该研究为高精度风洞天平并联复位机构提供了重要的设计依据。
Abstract：A 6-DOF (degree of freedom) parallel machine was used as the reset mechanism in a wind tunnel balance calibration system because of its simple structure and stiffness. A model was developed using the D-H (Denavit-Hartenberg) convention to analyze inaccuracies in the reset mechanism caused by joint manufacturing tolerances. In this model, each closed-loop kinematic chain was treated as a RRRPRR chain. The effects of the joint tolerances and structural parameters on the kinematic accuracy were calculated based on Qusai-Newton method. Simulations indicate that the inaccuracy is on the same order of magnitude as the joint offsets. A principle is given to determine the structural parameters needed to improve the accuracy of this type of reset system.
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2018, Vol. 58 
