一种利用同名像点位姿变化建立某型器物量测系统误差补偿新方法

A New Error Compensation Method for Certain Measurement System Using the Change of Position and Pose of Corresponding Image Points

  • 摘要: 运动误差可由位姿变化反映,基于此提出了一种利用同名像点位姿变化建立某型器物量测系统误差补偿新方法。该方法首先在位置1处观测,通过控制器主动做定量位姿变化到位置2,结合位置1处外方位元素与坐标转换原理得到位置2处外方位元素初始值,进而利用条件共线方程解得位置2处标定板角点拟合像素坐标;然后在位置2处观测,并将标定板中同名像点像素坐标作为观测值,与拟合值作差可列出误差方程式,迭代求解误差改正数;最后利用获得的多组误差数据,通过非线性最小二乘拟合获得运动误差补偿模型。实验表明,利用该方法检测运动误差无需测量仪器参与,操作便捷,代价成本低;此外,补偿模型所需参数较少,补偿后误差减小至亚毫米级。

     

    Abstract: Based on motion error can be reflected by position and pose change, a new error compensation method using position and pose change of corresponding image points to establish the error compensation model for certain measurement system is proposed. Firstly we observe at position 1, actively and quantificationally change to position 2 by the motion controller controls, combining with exterior orientation elements at position 1, the initial value of exterior orientation elements at position 2 can be obtained by coordinate conversion principle. Subsequently the coordinate values of fitting pixel in checkerboard calibration plate's corner points can be obtained by using collinear equation as well.Then, we observe at position 2, and establish the error equation by differentiating the observed values from the corresponding fitting one, herein motion error corrected values can be solved iteratively. Finally we can establish the error compensation model by nonlinear least square fitting of multiple sets of error data of each motion axis. The experimental results show that: The proposed method can compensate for system motion errors without involved in professional instrument, and it has the advantages of easy operation and low cost. Besides, the compensation model needs fewer parameters, the error can be reduced to sub-millimeter scale after compensation.

     

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