【作者】 吕孟军；

【导师】 游有鹏；

【作者基本信息】 南京航空航天大学 ， 机械电子工程， 2008， 硕士

【摘要】 光栅测量技术具有高精度、高灵敏性、动态范围大、易于实现自动化等特点,可实现对位移、速度等机械量的测量。为提高测量精度和分辨力,有效控制测量成本,莫尔条纹电子学细分技术被广泛研究和应用。本文对莫尔条纹电子学细分技术进行了深入研究,提出了提高细分精度和分辨力的解决方案。从基本原理上归纳总结实际应用中各种细分方法的实现途径和特点。重点对正切法细分技术进行研究并对细分精度影响因素进行理论分析;在常规信号调理的基础上,通过算法对莫尔条纹信号进行噪声控制和相位校正,可极大提高细分精度。为获得高质量信号,将神经网络自适应算法应用于莫尔条纹信号降噪。神经网络层实现信号的非线性映射,使线性和非线性噪声均能得到有效抑制;将滤波步长与信号频率构成函数关系,步长的动态调整和算法的自适应性保证了宽频带滤波效果。滤波后的莫尔条纹信号质量明显改善。基于正切法细分,提出了一种新的相位误差补偿算法,通过信号区间的分段处理,使短周期信号的各相角均可得到实时校正,有效降低了由于信号相位不正交引起的细分误差,并详细分析了算法的实现条件。仿真及实验表明,本文提出的算法可显著改善莫尔条纹信号质量;相关研究内容对于提高莫尔条纹电子学细分精度和倍数具有实际参考价值。更多还原

【Abstract】 Grating MoiréFringe technique is used to measure the mechanical position and velocity at present for its high precision, perfect sensitivity, wide dynamic range, automatization and so on. In order to improve the measurement distinguishment and precision and depress the application cost, the subdivision of MoiréFringe is studied and applied widely.The electric subdivision technique of MoiréFringe is studied perfectly and how to improve the subdivision precision and distinguishment are put forward in this thesis.The realizations and the characteristics of various subdivision methods according to the principle are summarized first. The tangent subdivision method of MoiréFringe is studied with emphasis and the factors which influence the subdivision precision are analyzed theoretically. To improve the subdivision precision, the signal noises should be restrained and the phase should be adjusted through algorithm.In order to obtain the signals with fine quality, the adaptive filtering algorithm based on neural network is used to restrain noises of MoiréFringe. The nonlinear mapping fuction is achieved by using the neural network layer. The step size of the algorithm can be adjusted dynamicly according to the signal’s frequency to meet the filtering request of signal with diversified frequency and make the algorithm self-adaptive. The signal quality is improved obviously by filtering.A new phase error compensation algorithm is worked out in allusion to the tangent method. The angle of a certain signal period can be emended by detaching the sections. The application of this algorithm can depress the subdivision error caused by signals not in phase quadrature. The realization of the algorithm is analyzed detailedly at the same time.Based on experiments, it is indicated that the signal quality improves obviously by using these algorithms introduced in this thesis. The study contents have reference value to improve the MoiréFringe subdivision recision.更多还原