A novel rotation speed uniformity evaluation method for the rotary laser scanning measurement system

Abstract For rotary laser scanning measurement systems, the rotation speed uniformity of the measurement part directly affects the system’s measurement accuracy. To monitor the details of the rotation speed changes within a cycle, this paper proposes a rotation speed uniformity evaluation method for rotary laser scanning measurement systems, which can both detect the rotation speed change within a cycle and obtain the speed change with the angular position. This method is expounded in detail, including the calibration of the rotary encoder gratings, the acquisition of the real-time rotation speed change sequence, and the post-processing of the rotation speed change sequence. The feasibility of the novel processing method is verified by comparison experiments: the novel method is compared with a speed signal processing method based on measuring of rotational periodicity to verify the feasibility. The measurement accuracy of the novel method was analyzed based on the theory of uncertainty propagation. Based on the verification results, the novel method was utilized to evaluate the speed uniformity of the transmitter at different speeds and analyzes the influence of rotation speed uniformity on the angular accuracy of the system, and the experimental results reveal that the novel method is able to detect the fluctuation of the rotation speed within a circle at different speeds, and for the transmitter, the higher working speeds has less relative speed changes and less angle measurement errors.