Enhancement of positioning accuracy of industrial robots with a reconfigurable fine-positioning module

• Published in: Precision engineering Vol. 34; no. 2; pp. 201 - 217
• Main Authors: Sulzer, Josef, Kovač, Igor
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.04.2010; Elsevier
• Subjects: Applied sciences; Automation; Costs; Exact sciences and technology; Fine-positioning module; Handling; Image processing; Industrial robots; Manufacturing engineering; Materials handling; Mechanical engineering. Machine design; Mechanical interface; Micro-handling; Modules; Precision engineering, watch making; Relative positioning; Robots; Scara Robot; Mechanical interface; Relative positioning; Micro-handling; Image processing; Fine-positioning module; Scara Robot; Positioning; Industrial robot; Position control; Precision engineering; High precision; Pattern recognition; Micromachine; Robotics; Micromanipulation; Microassembling
• ISSN: 0141-6359; 1873-2372
• DOI: 10.1016/j.precisioneng.2009.06.006

Conventional industrial robots achieve a high flexibility by low investment costs, but they are limited in absolute positioning accuracy. The costs for the introduction of a new special high precision robot for micro-handling are very high, where the workspace is limited to small areas. For handling operations, best results according velocity, precision and costs can be achieved with SCARA-type robots. Therefore, the introduction of a fine-positioning module for the enhancement of positioning accuracy of robots in the micro-handling techniques, become indispensable. The most micro-handling systems on the market have been designed for individual work-pieces. With our proposed fine-positioning module, we get a reconfigurable robot system for the execution of different handlings tasks both in the micro- and meso-scale 2 2 Micro-scale: typical part dimensions are in the range sub-millimeters up to a few millimeters with part features in the micrometer range, as a reference: the meso-domain is defined as products fitting in a box of 200 × 200 × 200 mm 3. in the industrial automation. To increase the flexibility of the robot system, the handling system is equipped with a tool change system, which allows an automated couple of the fine-positioning module with the Scara Robot. At this robot system, the Scara Robot will be used for coarse movements, and the fine-positioning module for very accurate positioning tasks. The fine-positioning module is equipped with a microscope, which enables in combination with an image processing system relative positioning technique, object recognition and measurements simultaneously. Handling of micro-objects and measurements are the major operations, which can be executed by the fine-positioning module.