SUBJECT: Ph.D. Proposal Presentation
BY: Joshua Vaughan
TIME: Monday, June 11, 2007, 4:00 p.m.
PLACE: MARC Building, 331
TITLE: Dynamics and Control of Mobile Cranes
COMMITTEE: Dr. William Singhose, Chair (ME)
Dr. Kok-Meng Lee (ME)
Dr. J. Rhett Mayor (ME)
Dr. John-Paul Clarke (AE)
Dr. Patricio Vela (ECE)


The rapid movement of machines is a challenging control problem because it often results in high levels of vibration. Motion-induced vibration limits the operational speed of the system. Input Shaping is one method that eliminates motion-induced vibrations by intelligently designing the reference command such that system vibration is cancelled. It has been successfully implemented on a number of systems, including bridge and tower cranes. Unfortunately, most cranes, once erected, have limited or no base mobility, limiting their workspace. The addition of base mobility could help extend the operational effectiveness of cranes and may also expand crane functionality. This also presents the possibility of using cranes in harsh and/or distant environments. Teleoperation of oscillatory systems, such as cranes, then becomes another avenue for advancement of crane functionality. Base mobility in cranes presents both additional control challenges and operational opportunities. A crane with base mobility is redundantly actuated (overactuated), such that multiple combinations of actuators can be used to move a payload from one location to another. This opens the possibility for the selection of a combination of actuation that provides both rapid motion and limited system vibration. The extension of input shaping into this operational domain will provide a method to maximize effective actuation combinations. Toward this end, new multi-input shaping methods will be developed and applied to a mobile tower crane located at Tokyo Institute of Technology and a mobile boom crane under construction at Georgia Tech. While mobile cranes will be the primary application example for this research, the advancement of input shaping theory will also benefit other multi-input multi-ouput control applications. These applications include hard disk drive (HDD) control, multi-stage machining, and micro/macro robotics.