Automated heavy load lifting and moving system using pneumatic cushions

摘要

This article presents a new control method for a pneumatic cushion for transporting heavy payloads. Pneumatic cushions are particularly useful for moving structural or non-structural components over hard, smooth floors. They can be put directly under load, lifted to a small height by applying air pressure and moved. A thin, friction-reducing air film is formed under the cushion during lifting. Currently, pressure is usually controlled manually, which causes difficulty in establishing an appropriate pressure value, especially when the load is distributed unevenly between multiple cushions. In practice, the pressure is often set higher than is necessary to move the load. Excessive pressure does not reduce friction, but increases air consumption. Hence, in this article an effort is described to obtain the minimum allowable pressure. The first part of the article includes the theoretical background, detailed models of the proposed automatic controllers and the parameters of a test bench. Experiments were carried out with a typical manual control system and two automatic controllers, with PID and fuzzy logic algorithms. The results indicate that automation of the control system significantly reduces air consumption and shortens the time needed to obtain the correct pressure. Moreover, it improves the stability of the load by allowing more accurate vertical positioning of individual cushions.