基于广义力平衡原理的Stewart平台机构标定

通过分析Stewart机构各运动副的制造误差和安装误差,以及其对雅可比矩阵的影响,利用雅可比矩阵和一阶静力影响系数之间的对偶关系,提出基于广义力平衡原理的Stewart平台机构标定方法。该方法通过测量平台各缸作用力,避免了测量虎克铰空间坐标难的问题。通过对平台进行广义力加载测量,得到平台平衡状态时互不相关的广义力和各单缸力的实验数据,最后利用最小二乘法拟合得出实际的一阶静力影响系数,从而标定出机构初始状态时的各铰点空间坐标。实验表明,该方法所标定出的Stewart平台机构参数,能使平台的运动学模型更为精确,有效地提高了平台的定位精度。

Kinematic Calibration of Stewart Mechanism Based on Generalized Force Principle

A new method based on generalized force principle for calibrating parallel robots was proposed. Nonlinear least squares was employed to determine the first-order static influence coefficient matrix by the measurements of the generalized forces and the articular forces. The actual parameters of Stewart mechanism can be calibrated by means of the measurements of the length of all legs and the relation of the first-order static influence coefficient matrix and Jacobian matrix The pose information was avoid to measure in the calibration processes. Experimental results show that the 42 identified parameters by the method obtain the more accurate kinematic model and increase the position accuracy of Stewart mechanism.