Chord error constraint based integrated control strategy for contour error compensation

Abstract

As the traditional cross-coupling control method cannot meet the requirements for tracking accuracy and contour control accuracy in large curvature positions, an integrated control strategy of cross-coupling contour error compensation based on chord error constraint, which consists of a cross-coupling controller and an improved position error compensator, is proposed. To reduce the contour error, a PI-type cross-coupling controller is designed, with its stability being analyzed by using the contour error transfer function. Moreover, a feed rate regulator based on the chord error constraint is proposed, which performs speed planning with the maximum feed rate allowed by the large curvature position as the constraint condition, so as to meet the requirements of large curvature positions for the chord error. Besides, an improved position error compensation method is further presented by combining the feed rate regulator with the position error compensator, which improves the tracking accuracy via the advance compensation of tracking error. The biaxial experimental results of non-uniform rational Bsplines curves indicate that the proposed integrated control strategy can significantly improve the tracking and contour control accuracy in biaxial contour following tasks.

Adaptive nonsingular terminal sliding mode control of robot manipulator based on contour error compensation

“…One of the main reasons is the lack of coordination of the robotic manipulator 7 . An integrated control strategy of cross-coupling contour error compensation based on chord error constraint, which consists of a cross-coupling controller and an improved position error compensator, was proposed by Zhang et al 8 . Kommaneesang et al 9 pointed that only a few researchers concentrate on solving the contouring problem in the robotic machining system, and the contouring control problem was transformed into the regulation problem by using the method of equivalent errors.…”

Feedforward combined multi-axis cross-coupling contour control compensation strategy of optical mirror processing robot

“…Numerous scholars have also conducted research and application for the contour error control and compensation of different machine tools. To improve the accuracy of large-curvature position tracking and contour control, Zhang et al proposed a position compensation method composed of a cross-coupling controller and an improved position error compensator [26]. Izadbakhsh et al designed the controller of electric manipulator with Szász-Mirakyan operator as the basis function and proved that Szász-Mirakyan operator plays a good role in uncertainty compensation and improving tracking error [27].…”