Mobile Robot Navigation in Narrow Aisles with Ultrasonic Sensors

This paper describes an experimental obstacle avoidance system for mobile robots traveling through the narrow aisles of a warehouse. In our application the aisles are 91 cm (36") wide and the robot has a width of 64 cm (25"), but the method described here is generally applicable to a large class of narrow-aisle navigation applications. Our approach is based on the carefully designed placement of ultrasonic sensors at strategic locations around the robot. Both the sensor location and the associated navigation algorithms are designed in such a way that whenever accurate range data is needed (e.g., for servoing) a sensor is located so that its accurate radial measurements provide the required data.