Cranes are widely used in material-handling and transportation applications, e.g. in shipyards, construction sites, and warehouses. They are critical to the economic vitality of modern-day industries. Therefore, improving crane performance and ease of use are important contributors to industrial productivity, low production costs, and crane safety.
This thesis aims to improve crane performance in two major aspects. The first component is improving the human-machine control interface. An intuitive interface was developed that allows operators to drive a crane by simply moving a small radio-frequency tag through the desired path. Real-time location sensors are used to track the movements of the tag and its position is used in a feedback control loop to drive the crane. Facets of this novel interface will be examined, e.g. control structure, stability, usable contexts, modes of operation, and quantitative measures of improvement over standard crane control interfaces.
The second component of this research is an investigation of the dual problems of payload lift-up and lay-down. In lift-up, when the hoist is not positioned vertically over a payload, hoisting of the suspension cables will cause the payload to be lifted off the ground at an angle, which causes unwanted initial oscillations. The lay-down problem examines the difficult task of laying down distributed payloads (e.g. a long aluminum ingot) from a vertical orientation to a horizontal position. For both problems, the dynamics will be derived and experimentally verified, and practical control solutions will be proposed.