An Active Compliance Adsorption Method for Climbing Machining Robot on Variable Curvature Surface

Abstract

This article proposes an active compliance adsorption method for a negative pressure adsorption climbing robot with 3 active compliance suction units which integrate 3 degree of freedom active compliance actuators along with flexible adsorption chambers. This method enables the climbing robot to adsorb and move stably on the surface of large and complex components with variable curvature for machining purposes. The main contribution lies in two aspects. First, an adsorption performance indicator (API) depicting the stretch of the flexible sealing lip is proposed by analyzing the leaked airflow of the climbing robot's suction unit. Second, the pose control method of the suction chamber based on the real-time estimated adsorbed surface is proposed, where the API is used as the optimization target. The experiments have been performed and the results show that a 10 kg-weight climbing robot with three active compliance suction units can keep adsorption force over 1000 N when the surface's curvature radius changes continuously from 1.1 to 14.6 m, with a significant increase in the adsorption force up to 156% compared with only pure passive compliance adsorption method.