航天遥感仪器的光学装调需要使用大型精密调节架,其俯仰角调节机构使用步进电机驱动,且传动比为非线性,因此控制难点在于如何以步进电机开环方式来实现调节架俯仰角的精确运动。通过对现有调节架的俯仰角运动机构进行建模分析,得到其运动学模型为偏心曲柄滑块机构。根据运动学公式,分析了当前使用的控制方法精度不高的原因,并提出了新的控制方法。在此基础上,为了验证新方法下调节架俯仰角的运行结果,引进了全新的测量工具——激光跟踪仪。根据测量结果,绘制出俯仰角的目标值和误差曲线图,分析误差规律并修正。

The optical alignment of aerospace remote sensor needs large precision stage, and its pitching angle, which has nonlinear transmission ratio, is driven by stepping motor. The problem is how to acquire accurate motion results of the pitching angle by stepping motor in open loop. By analyzing the principle of the stage, the mechanical model of its pitching angle is an eccentric slider-crank mechanism. Then, according to the mechanics formula, the reason of inaccurate motion result of the pitching angle is analyzed. Besides, a new control method for the pitching angle is proposed . On the basis of this, to validate the new method, laser tracker is introduced as a new measurement of the pitching angle. According to the measurement results, the chart of the target angle and the motion error is drawn, and then it is analyzed and corrected. After the error correction, the motion accuracy of the pitching angle finally meets the requirement of optical alignment.