Automatic and Flexible Transport System Based on Mobile Robots

This paper describes the development of a mobile robot based on a fork lift truck. This system has been tested in a ham industry and permits to integrate the previous transport system of the factory. In this way, the transport and storage can be done using fork lift trucks, mobile robots or both, and all of them controlled by a planning program. The planner obtains information from an automaton about the kind of product that arrives via the production line, and based on the state of the plant, it decides which robot is going to be used and where it has to transport the load. Localization of the mobile robot in the plant is performed by two infrared sensors and a laser telemeter on board, that is able to give angular and distance measures to beacons located in the plant. 1. INTRODUCTION The quick evolution of the Information Technology , Control, Computers and Comunications, support the idea of Computer Integrated Manufacturing (CIM). This concept groups a great variety of disciplines and techniques, among which Flexible Manufacturing System (FMS) are of special importance (Puente et al., 1984). The aparition of the Flexible Manufacturing Systems (FMS) has driven to reconsider the continuous transport systems such as conveyors because of the low exi-bility to changes in the demands of the production. The continuous transport systems are rigid, the paths followed by the products are xed, and modiications of the paths obligue to important changes in the plant connguration. On the other hand, operator-driven vehicle systems are very exible but they are not automatic systems and therefore cannot be integrated in a FMS. An at-temp to solve these problems has been the utilization of Automatic Guided Vehicles (AGV). An AGV system can be deened as an organized transport and material handling system composed by autonomous vehicles with independent movement that follow predeened trajectories on the oor, built as, painted lines, buried lines, magnetic stripes, etc. In spite of these advantages, these systems do not have complete exibility because the trajectories are completely preexed, and a change in the productive process (change of machinery , storage, etc) implies a high cost because of the consequent modiication of the guiding sys