Study On Electronic Subdivision Of Grating MoiréFringe

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.