Subdivision Method for Nonorthogonal Moiré Signals

Moiré signal subdivision is essential to the application of gratings. Focusing on the complexity and difficulty of quadrature compensation for the Moiré signals, we propose a new method that can directly subdivide nonorthogonal Moiré signals. A detailed description of the digital subdividing system for this method is provided herein. Compared with conventional methods, the proposed method requires fewer hardware resources and features shorter delays. The effects of various parameters on the subdivision process are discussed, and the quantitative relationships between the signal amplitude ratio, signal sampling frequency ratio, and subdivision value are determined. Finally, evaluation tests are performed using a laboratory-made field-programmable gate array subdivision circuit. The results confirmed the effectiveness of the subdivision method, revealing a subdivision error of less than 0.6".