基于并联机构的六分量并联天平及其力雅可比矩阵研究

Six Axes Parallel Balance Based on Parallel Mechanism and Analysis of Its Force Jacobian Matrix

为了由感测力导出被测模型受力 ,必须研究基于Stewart平台六维力传感器的力变换关系。本文将并联机构引入风洞天平 ,提出了并联天平的概念 ,应用并联机构学理论 ,对并联天平实现的关键理论问题即天平感测力与被测模型上所受的六维力的转化关系进行了研究 ,得到了二者转化的力雅可比矩阵 ,同时推导出基于 5个基本结构参数的雅可比矩阵条件数 ,并用数值算例加以验证。

In order to measure forces and torques acting on the testing model of the 6 axis force transducers based on the Stewart platform, the Jacobian matrix between the external force and the given six leg forces are required. This paper deals with the force Jacobian matrix of wind tunnel balance based on parallel mechanism, and the concept of parallel balance is put forward. By the theory of the parallel mechanism, the relationship between forces and torques applied to the testing model and the given six leg forces is derived, the force Jacobian matrix for the balance is obtained, and the Jacobian matrix condition number based on five elementary structural parameters is achieved. In order to investigate the validity of the proposed method, a numerical example is given.