A Concept for Intelligent Tool Exchange System for Industrial Manipulators

For years now, the industrial manipulators have substituted human in many types of works during the manufacturing process. With robots the production rate increases, as does the quality of the product. The application of industrial manipulators increases the safety in the factories which in turn leads to savings. However, there are several difficulties in introduction of robotics into the production line. One of them is usually large cost of purchase and implementation of the robot. The proposed concept of the intelligent system for tool exchange is to address the stated issue. The aim of the system is to provide a mechanism for quick tool exchange supported by a decision making module that will constitute the self-reconfigurable industrial manipulator that is able to assess the situation at the production line, recognize the product and make decision on the operations to be performed, their sequence and which tool to use to perform that operation. Such a system of manipulator equipped with functions for reconfiguration and adaptation will be a solution for all applications where the production assortment changes quickly and is made in short series, and in particular for SMEs, which cannot afford purchase of several robots. They would buy one instead and let it perform variable tasks.The article briefly presents the concept of the hardware part of the exchange system, which includes both construction and the electronic modules for the tools, and concentrates on the concept of software expert system and database that allows intelligent decision making. The software control of the system is divided into four levels: the basic level, technical level, task level and procedure level. The basic level defines the movement of the robot such as: positioning, rotation, approach to the position etc. This level uses to control system of the applied manipulator and the data contained in the electronic modules of the tools. The basic level reflects the typical low-level control of the manipulator. The technical level defines the technical movement of the robot, small procedures related to the calibration of the tools, operation with the tool magazine (picking up and putting away) and related to tool maintenance – locking, unlocking, power supply, air supply and similar. The task level defines the operations related to the task performed on the object. Depending on the defined task the proper tool is selected (e.g. gripper, camera or a laser scanner) and, based on the data collected from sensors, performs the operation (e.g. scans the surface of the object). The highest level of control is totally independent on the hardware control system of the manipulator and the hardware of the robotic stand. Using the available databases and the recognition systems (e.g. cameras) makes decisions on what type of object appears on the production line and what operation is to be performed. The operations are defined as metacode that is interpreted and performed by lower control levels structurally bound to the control system of the manipulator.