An algorithm for on-line path planning of autonomous mobile overhead traveling crane based on obstacle information

This paper presents a method for establishing a three-dimensional (3-D) autonomous mobile overhead crane system that takes into account obstacle avoidance and path planning real-time. It is especially necessary for the real-time path planning occurring during transferring to be carried out relatively quickly. This paper describes a method of path planning that can be carried out in a short time with an easy algorithm. This target crane system has three different parts: a visual system, a planning system, and a control system. In the visual system, ultrasonic sensors are used to renovate a partial environmental map during transferring with the quick scanning time. In the planning system, a proposed on-line path-planning method based on the expanded path-planning method of Srinivas allows for changes such as a change in the transportation environment to be made during the transferring. On-line path planning has been achieved using information regarding obstacles around the object being manipulated, as obtained by ultrasonic sensor. Finally, we have deduced the optimal parameter to transfer environment in consideration of transfer time and transfer cost.