Determination of control parameters for a radio-frequency based crane controller

Human operators have difficulty driving cranes quickly, accurately, and safely because of the sluggish response of the massive structure and large payload swings. Manipulation difficulty is also increased by non-intuitive crane-control interfaces that consist of buttons and levers. A new type of crane-control interface allows operators to drive a crane by simply moving a small radio frequency emitter through the desired path. Real-time-location sensors track the movements of the radio tag. The tag position is used in a proportional feedback control scheme to drive the crane trolley toward the tag. Unfortunately, the crane payload usually responds with large-amplitude swings. Feedback control of the payload swing is not implemented, due to the difficulty of measuring the payload state. Instead, an input-shaping control element is used to limit swing. Simulations of the crane dynamics are used to select a good combination of feedback gains and input-shaper parameters. Experiments performed on an industrial bridge crane verify the effectiveness of the proposed control approach.