School of Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing 100191, China.
Microsc Res Tech. 2012 Sep;75(9):1281-91. doi: 10.1002/jemt.22062. Epub 2012 Apr 19.
Microscopic vision measurement precision has been largely limited by inaccurately calibrated model parameters, because image plane is near parallel to reference plane in the narrow depth of field. This article proposes a method of precise microscopic vision measurement based on the adaptive positioning of the camera coordinate frame. The microscopic vision measurement movably attaches the origin of the camera coordinate frame along the optical axis. By finding the optimal position, the nonlinearity of the objective function in calibration optimization is decreased and the optimization sensitivity to initial values is reduced. Therefore, we obtain a high calibration precision and eventually ensure a high measurement precision. Mathematical simulations illustrate that the calibration precision of the proposed microscopic vision measurement model is higher than that of the conventional vision measurement model. The experiment shows that with magnification of 3.024×, the presented system achieves a precision of 0.12% based on the proposed microscopic vision measurement model, which is two times higher than the one based on the conventional vision measurement model.
微观视觉测量精度在很大程度上受到校准模型参数不准确的限制，因为在小景深中，像平面接近于参考平面。本文提出了一种基于相机坐标系自适应定位的精密微观视觉测量方法。该微观视觉测量可沿光轴移动相机坐标系的原点。通过找到最佳位置，可以降低校准优化中目标函数的非线性，减少优化对初始值的敏感性。因此，我们获得了较高的校准精度，最终确保了较高的测量精度。数学模拟表明，所提出的微观视觉测量模型的校准精度高于传统视觉测量模型的校准精度。实验表明，在放大倍率为 3.024×的情况下，所提出的系统基于所提出的微观视觉测量模型实现了 0.12%的精度，比基于传统视觉测量模型的精度提高了两倍。
