四象限探测器边缘响应的非线性误差补偿方法研究

Research on nonlinear error compensation methods for edge responses of quadrant detectors

摘要:

针对空间激光通信领域中四象限探测器边缘响应存在非线性的问题,研究了一种Tanh-ADRC复合控制方法来补偿非线性误差,建立了基于二维高斯光斑与Tanh饱和函数的非线性误差模型,通过构建非线性扩张状态观测器并融合双曲正切函数特性,设计非线性前馈补偿项与状态误差反馈控制律,实现对非线性饱和误差的主动修正；通过MEMS快反镜-光模块-四象限探测器闭环实验平台,控制MEMS快反镜偏转角度在[－11.7mrad ~ 11.7mrad]范围内,Tanh-ADRC复合控制方法使得光斑最大定位误差降至±0.027mrad,平均误差较无补偿情况降低24.9%,有效改善了传统ADRC在大偏移量下的估计失真问题；该方法提升了四象限探测器在强非线性区域的定位精度与鲁棒性,为空间激光通信中高精度、高稳定性的精跟踪系统设计提供了新的思路与实现路径。

Abstract:

Addressing the issue of nonlinearity in the edge response of four-quadrant detectors in the field of space laser communication, this study investigates a Tanh-ADRC composite control method to compensate for nonlinear errors. A nonlinear error model based on a two-dimensional Gaussian spot and the tanh saturation function is established. By constructing a nonlinear expanded state observer and integrating the characteristics of the hyperbolic tangent function, a nonlinear feedforward compensation term and state error feedback control law were designed to achieve active correction of nonlinear saturation errors; Through a closed-loop experimental platform comprising a MEMS fast-response mirror, optical module, and four-quadrant detector, within the control range of [－11.7 mrad to 11.7 mrad], the Tanh-ADRC composite control method reduced the maximum error to ±0.27 mrad, with the average error decreasing by 24.9% compared to the uncompensated case, effectively addressing the estimation distortion issues of traditional ADRC under large offset conditions; This method enhances the positioning accuracy and robustness of the four-quadrant detector in strongly nonlinear regions, providing new insights and implementation pathways for the design of high-precision, high-stability tracking systems in space laser communication.