Design of 4-DOF radial floating passive compliant end-effector used for polishing

Abstract

Manipulators applied to polishing can avoid the harm of dust and noise to workers’ health in manual polishing, and can significantly increase productivity. The degrees of freedom (DOF) of the existing end-effector for manipulator polishing is insufficient, and then it is difficult to adapt to complex surfaces. A passive compliant end-effector (PCEE) with 4-DOF employing pneumatic floating was designed to solve that problem in this article. According to the included angle between the floating spindle and the plunger, the supporting force functions of floating amount were constructed. Considering the characteristics of the supporting force and the operating modes comprehensively, an appropriate number of plungers was selected. Based on the equilibrium principle of spatial force system, a PCEE was designed by using the floating scheme at both ends, and then a physical model and a simplified model were provided. Eventually, the performances of 4-DOF PCEE are compared with those of the existing 2-DOF compliant end-effector (CEE). The results show that The PCEE can float with 4-DOF; when the number of plungers is 9, all performances meet the design requirements; the polishing force can adapt to the local bulges and overcome the error reflection; the 4-DOF PCEE can adaptively fit the surface to reduce its geometric error.