Signal Acquisition and Non-linear Error Compensation for Random Rotating Angle Measurement by Laser Interferometry

摘要

In order to enlarge the measurement range of rotating angle by dual-frequency laser interferometry and realize the measurement of random rotating angle, a new method to linearize the measurement principle by processing of two orthogonal signals is proposed. Two sets of identical interferometers spatially perpendicular to each other are used to generate the two orthogonal signals and a linearized output is then obtained by the difference of absolute values of the two orthogonal signals. In order to further reduce the non-linear error to satisfy the need of high-precision measurement, a method of error compensation, which is dead against its source directly, is also proposed. The compensation value is produced by calculating the remainder error of the linearized function.