基于改进谱线增强的光电编码器γ辐射噪声滤波算法研究  

γ-radiation noise-filtering algorithm for optical encoder based on improved adaptive line enhancer

作　　者：董威 王中华 姜潮[1,2] 邱添 DONG Wei;WANG Zhonghua;JIANG Chao;QIU Tian(State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle,Hunan University,Changsha 410082,China;School of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学整车先进设计制造技术全国重点实验室,长沙410082 [2]湖南大学机械与运载工程学院,长沙410082

出　　处：《核技术》2024年第8期67-78,共12页Nuclear Techniques

基　　金：国家自然科学基金(No.52235005,No.52205262)资助~~。

摘　　要：针对核辐射环境下光电编码器因受γ辐射总剂量效应影响而导致输出信号质量劣化的问题,提出了一种兼顾精度和效率的改进谱线增强算法(Improved Adaptive Line Enhancer Method,IALEM)。该算法引入Softsign函数建立误差与步长之间的非线性关系,通过在步长更新公式中引入前一时刻步长值,达到收敛速度快且稳态误差小的目的。分别在算法收敛速度、稳态误差、低信噪比输入、计算量4个方面与同类算法进行比较。结果表明,该算法在拥有较低计算量的同时,其收敛速度更快、稳态误差更小,并且对于低信噪比信号具有更好的滤波效果。最后,在光电编码器上对本文所提算法进行了现场可编程门阵列(Field Programmable Gate Array,FPGA)硬件实现;并在60Co γ辐射环境中对算法的滤波效果进行了实验测试。实验结果表明:所提出的算法可有效滤除光电编码器因γ辐射产生的噪声,提高光电编码器输出信号的质量。[Background]The output signal quality of optical encoder in nuclear radiation environment is degraded due to the total ionizing dose(TID)effect ofγradiation.[Purpose]This study aims to propose an improved adaptive line enhancer method(IALEM)that considers accuracy and efficiency to minimize the degradation of the output signal quality of photoelectric encoders in nuclear radiation environments caused by TID effect ofγradiation.[Methods]Firstly,the Softsign function was introduced into the least mean square(LMS)algorithm to establish the nonlinear relationship between the error and the step size.Then,rapid convergence and small steady-state errors were achieved by introducing the previous step size value in the step-size-updating formula.Furthermore,this improved adaptive line enhancer method(IALEM)was compared with similar algorithms in terms of four aspects:convergence speed,steady-state error,low signal-to-noise input,and computational volume.Finally,the proposed algorithm was implemented in a field programmable gate array (FPGA) chip and verified on a photoelectric encoder platform, andits filtering effect was experimentally validated in a cobalt-60-source γ-radiation environment. [Results] The resultsshow that the proposed algorithm yields a higher convergence speed, lower steady-state error, and better filteringeffect than that of other algorithms for low signal-to-noise ratio signals with less computational effort. Uniformityerror and orthogonality error of the photoelectric encoder output signal after filtering by IALEM are reduced by17.6% and 8.0%, respectively. [Conclusions] The experimental results show that the proposed algorithm caneffectively filter out the noise generated through γ radiation and improve the output signal quality of the photoelectricencoder.

关 键 词：光电编码器 变步长 改进谱线增强算法 辐射噪声滤波 

分 类 号：TL99[核科学技术—核技术及应用]