Research on the collaborative machining method for dual-robot mirror milling

To achieve the green and efficient processing of weak rigid large thin-walled aerospace parts, mirror milling systems are replacing traditional processing methods. A novel dual-robot mirror milling system consisting of a machining hybrid robot, supporting hybrid robot, and fixture is presented in this study. The cutter and the flexible supporting head are installed at the end of the machining robot and the supporting robot respectively. Because the deformation and vibration of the workpiece are directly affected by the collaborative performance of the cutter and the supporting head, the key problem is how to achieve collaborative machining by the cutter and the flexible supporting head in equal wall thickness machining. A collaborative machining method is proposed by establishing a relative pose relationship between the cutter and the supporting head. In this method, the cutter trajectory of the machining robot is generated in real time according to the end trajectory of the off-line planning supporting robot and the preset machining parameters. Next, the control parameters of each driving motor are obtained by the kinematics for the machining robot. A dual-robot endmost geometrical pose is used to obtain the machining wall thickness via contact-type online measurement for replacing ultrasonic thickness measurement systems. The wall thickness error is compensated by the machining robot for accurately controlling the machining thickness. Finally, a triangular grid is machined to verify the effectiveness of the proposed machining method in the proposed mirror milling system.