Research Of Subdivision Technology Of Grating Moiré Fringe Based On Amplitude Sampling

High precision measurement technology has an important effect on the performance of modern NC machine tools, various kinds of precision measurement equipments based on MoiréFringe is widely applied. However, just using grating MoiréFringe signal to measure the positions can not meet the challenge of high precision measurement. Therefore, many kinds of subdividing technology of MoiréFringe signal have been developed, such as Four Times Subdivision, Resistance Chain Subdivision, Phase Locking and Multiple-Frequency Subdivision, Carrier Wave Modulation Subdivision and Amplitude Segmentation Subdivision. There is still a certain insufficiency when all these technologies are applied to the specific field of high speed and high precision machine tool position subdivision. This thesis studies the subdividing technologies of MoiréFringe signal in the position feedback system of NC machine tool. Adequate MoiréFringe subdivision equipment applied to NC machine tool of high speed and high precision is designed on the premise of full consideration of subdividing speed.This thesis is mainly divided into three parts as follows:First, the subdividing plan is proposed. Based on the integrated discussion of updated grating MoiréFringe subdividing technologies, the suitable high speed and high precision NC machine position feedback system, namely the amplitude sampling subdivision is fixed on; then matlab is employed to emulate the theory of amplitude sampling subdivision. After that the detailed studying program is put forward.Second, the design method of software and hardware is employed, and subdividing circuit platform is established. The software adopts modularization programming design and uses C language and VHDL to program SCM and CPLD.Third, the subdividing results are proposed, based on which error analysis is taken effect. On the basis of the measurement of laboratory results, the error of circuit trial platform is determined and the potential reasons which lead to the error are found out. Consequently, several solutions are put forward. In addition, Matlab is also used to theoretically discuss the effect of subdivision and the quality of the original signal as well as the degree of the influence.