Three-dimensional obstacle avoidance online path-planning method for autonomous mobile overhead crane

This paper presents a method for establishing a three-dimensional (3-D) autonomous mobile overhead crane system that takes into account obstacle recognition and path planning online. It is especially necessary for the online 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 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 online 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. Online path planning has been achieved using information regarding obstacles around the object being manipulated, as obtained by ultrasonic sensor. Finally, we have confirmed the usefulness of the proposed method by simulation.