Sensor-based navigation control and calibration of a wafer-handling mobile robot

In this paper, the authors propose a mobile robot composed of a free-ranging automated guided vehicle and a manipulator with six degrees of freedom, which is mounted on the vehicle. In navigation in the semiconductor manufacturing line, the mobile robot utilizes a predefined map representing the route to move in the working area with clean class 1. The map and the information about the task to be performed is transmitted to the main controller of the mobile robot through R/F communication. In navigation, the mobile robot uses a fuzzy control algorithm based on data from the sonar sensors attached to both right and left sides of the vehicle to maintain a positioning accuracy within /spl plusmn/1 cm. The mobile robot automatically calibrates the setting position of the manipulator to calculate the exact destination point where the given task should be carried out. Then, the manipulator loads the equipment with wafer-carriers or unloads wafer-carriers from the equipment in the semiconductor manufacturing line. By the proposed navigation algorithm based on fuzzy control and the calibration algorithm of the manipulator, the mobile robot efficiently carries out a given task in a semiconductor manufacturing line.