Auxiliary support path planning for robot-assisted machining of thin-walled parts with non-uniform thickness and closed cross-section based on a neutral surface

Abstract

The robot-assisted support machining is useful in avoiding machining deformation and chatter for thin-walled parts. However, existing research mainly focus on support machining of thin-walled parts with equal thickness, such as the aircraft skin, and it is challenging for parts with non-equal thickness because the machining and supporting paths can hardly be harmonized. This paper proposes an auxiliary support path scheduling method for machining of thin-walled parts with non-equal thickness and closed section, such as blades, based on a defined “neutral surface”. A spatial convolution algorithm is presented to generate the neutral surface, reflecting the weighted average of the parts on the thinnest direction, and bridging the machining and supporting paths. With the proposed method, the planned auxiliary support path without frequent reciprocation, self-intersections, and interference can be generated, which makes the robot-assisted support machining strategy applicable for thin-walled parts with non-equal thickness and closed section. Both simulation and experimental tests are conducted. It can be seen from the results that the proposed method can effectively reduce the machining deformation and chatter, and the surface roughness is reduced by >50 %.