Design of a Roll Angle Measuring Sensor

Aiming at the measurement of roll deformation between two devices, we propose a novel scheme and elaborate the structure design in this paper. The scheme can realize the relative measurement of roll angle even if the system does not provide a reference datum, which effectively solves the problems of limited measurement range of moiré fringes and accuracy guarantee only in an extremely small angle range. First, the principle of measuring the roll angle by moiré fringes is introduced, and the effects of various error sources in the system are comprehensively considered. Then, the combined measurement scheme and the entire system composition structure are analyzed in detail. In addition, an experimental setup is designed to verify the accuracy of roll deformation measurement. The measurement results show that the root mean square (RMS) error can reach $6.9^{\prime \prime }$ within 3°, and is less than $7.8^{\prime \prime }$ in the range of 0°-90°. Hence, our proposed scheme has a good measurement stability in a large roll range.