Inverse kinematics of a redundant manipulator for cam integration. An industrial perspective of implementation

Abstract

Current CAM (Computer Aided Manufacturing) platforms store the toolpath information as a set of positions and orientations of the milling tool in a Cartesian Coordinated System defined in the working space, being the most standardized both G code (DIN 66025) and APT code (DIN 66215). These platforms come prepared for the control and postprocessing of up to a maximum of 5-axis trajectories (i.e., three positioning coordinates and two orientation angles of the milling tool), which supposes no indecisions in conventional CNC machines. In the case of manipulating the milling tool by means of redundant workcells, a profuse kinematic analysis of the robotic system is required before any work is carried out. In this article, the inverse kinematics of a complex KUKA robotic system for milling works is described, consisting of one robotic manipulator (KUKA KR15/2 with 6 rotary joints) mounted on a linear axis and synchronized with a rotary table. Thus, the possible effective control to carry out trough the commercial controller KUKA KRC2 is also faced up, in order to analyze the postprocessing possibilities from NX™'s CAM platform. As main contribution, after studying the capabilities of the set, a functional postprocessor is programmed inside the CAM, improving the communication between software and manipulator. It is easily applicable on any industrial robot by the same guidelines.