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ABSTRACT: The implementation of a postprocessor for the NX™ platform (Siemens Corp.) is described in this paper. It is focused on a milling redundant robotic milling workcell consisting of one KUKA KR 15∕2 manipulator (6 rotary joints, KRC2 controller) mounted on a linear axis and synchronized with a rotary table (i.e., two additional joints). For carrying out a milling task, a choice among a set of possible configurations is required, taking into account the ability to avoid singular configurations by using both additional joints. Usually, experience and knowledge of the workman allow an efficient control in these cases, but being it a tedious job. Similarly to this expert knowledge, a stand‐alone fuzzy controller has been programmed with Matlab’s Fuzzy Logic Toolbox (The MathWorks, Inc.). Two C++ programs complement the translation of the toolpath tracking (expressed in the Cartesian space) from the NX™‐CAM module into KRL (KUKA Robot Language). In order to avoid singularities or joint limits, the location of the robot and the workpiece during the execution of the task is fit after an inverse kinematics position analysis and a fuzzy inference (i.e., fuzzy criterion in the Joint Space). Additionally, the applicability of robot arms for the manufacture of big volume prototypes with this technique is proven by means of one case studied. It consists of a big orographic model to simulate floodways, return flows and retention storage of a reservoir in the Mijares river (Puebla de Arenoso, Spain). This article deals with the problem for a constant tool orientation milling process and sets the technological basis for future research at five axis milling operations.
AIP Conference Proceedings. 11/2009; 1181(1):119-129.
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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 NXtrade'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.
Mechatronics, 2009. ICM 2009. IEEE International Conference on; 05/2009
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ABSTRACT: Nowadays, the use of kinematically redundant robotic workcells for machining tasks is increasing. It is due to their capacity to avoid singular configurations, although a choice among a set of possible configurations is required. Experience and knowledge of the workman in charge of the manufacturing process allow carrying out an efficient control of the movement in these cases. However, it is a tedious job. This article presents an effective implementation of a CAM-robotics integrated fuzzy postprocessor based on the position analysis. It is focused on a workcell consisting of one robotic manipulator (KUKA KR15/2 with 6 rotary joints) mounted on a linear axis and synchronized with a rotary table. After the implementation of the inverse kinematics position analysis, a stand-alone fuzzy controller has been programmed with Matlab's fuzzy logic toolbox (The MathWorks, Inc.). Two C++ programs complement the translation of toolpath position information from the NX-CAM platform (NXtrade-Siemens Corp.) into KRL (KUKA robot language), in order to adequate the location of the robot and the workpiece in the execution of the task and avoiding singularities or joint limits. This article solves the problem for a constant tool orientation milling process and sets the technological basis for future research at five axis milling operations.
Mechatronics, 2009. ICM 2009. IEEE International Conference on; 05/2009
