基于掩光能量的球形验证质量块位置确定方法和误差分析
基于掩光能量的球形验证质量块位置确定方法和误差分析
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作者：
Hou Zhendong;Wang Zhaokui;Zhang Yulin
为了满足空间重力探测的苛刻要求，作为关键载荷的重力参考传感器（GRS）需要提供超高精度和低干扰的证明质量的相对位置。研究了带球面质量的GRS的位置确定和误差分析。首先提出了用光学阴影传感器测量自由落体防质量的概念。然后，基于光信号模型，导出了定位的一般公式。提出了两种测量系统，并对其进行了三维位置解析求解。第三，在高斯光束的假设下，分别给出了光斑大小和光功率变化、光束发散效应、光束中心抖振和光束方向偏差的误差传播模型。最后，在考虑光束发散、球面边缘和光束衍射等模型不确定性的情况下进行了数值模拟，验证了误差传播模型的性能。结果表明，该模型能较好地估计误差源的影响，精度优于20%。此外，对其中一个测量系统的三维位置确定进行了仿真，结果表明，位置误差与每个传感器的输出误差相当。
To meet the very demanding requirements for space gravity detection, the gravitational reference sensor (GRS) as the key payload needs to offer the relative position of the proof mass with extraordinarily high precision and low disturbance. The position determination and error analysis for the GRS with a spherical proof mass is addressed. Firstly the concept of measuring the freely falling proof mass with optical shadow sensors is presented. Then, based on the optical signal model, the general formula for position determination is derived. Two types of measurement system are proposed, for which the analytical solution to the three-dimensional position can be attained. Thirdly, with the assumption of Gaussian beams, the error propagation models for the variation of spot size and optical power, the effect of beam divergence, the chattering of beam center, and the deviation of beam direction are given respectively. Finally, the numerical simulations taken into account of the model uncertainty of beam divergence, spherical edge and beam diffraction are carried out to validate the performance of the error propagation models. The results show that these models can be used to estimate the effect of error source with an acceptable accuracy which is better than 20%. Moreover, the simulation for the three-dimensional po- sition determination with one of the proposed measurement system shows that the position error is just comparable to the error of the output of each sensor.