Aiming at the requirement that the brush head must maintain a specific distance from the curved surface during the cleaning operation of complex surfaces such as vases and cultural relics, this paper proposes a fixed‐distance control method based on distance feedback from three non‐collinear points at the end effector. The method collects distance information through three laser ranging sensors arranged in a triangular distribution, calculates the position deviation by averaging the three‐point distances and dynamically adjusts the position of the end effector to maintain the preset working distance. To improve the ranging stability and accuracy of the sensors, moving average, weighted moving average, median filtering, Kalman filtering, and a combined filtering algorithm of moving average + weighted moving average are introduced. Comparative experiments verify that the Kalman filtering algorithm under a sampling period of 180 ms is optimal, reducing the root mean square error (RMSE) of distance measurement to 0.11 mm. To verify the effectiveness of the method, a compact cleaning robotic arm is designed, which realizes the combined motion of low‐precision large‐angle movement of the arm and high‐precision small displacement of the end effector through a single‐chip microcomputer and a bus servo control module. Experimental results show that the coordinate deviations of the system are controlled within 1.5 and 2.02 mm in fixed‐distance vertical and horizontal motion experiments, respectively; in the irregular curved surface experiment, the maximum deviation is 1.35 mm and the RMSE is 0.61 mm, meeting the precision requirements for complex surface cleaning.
Zhang et al. (Thu,) studied this question.