A bilevel control architecture for rapid magnet cycling

Describes a bilevel controller architecture for rapid magnet cycling. The design of the controller is motivated by applications in accelerator mass spectrometry, where the command signal is typically piecewise constant and periodic. The controller consists of a low level component, which provides disturbance rejection, and a high level component, which provides tracking capability. The low level component is a conventional fuzzy controller that uses the output error and change of error to update the control signal at every sampling interval. The high level component updates the control signal at every cycle of the periodic command signal, using feedback from the previous cycle and a gradient algorithm. The authors present results from empirical studies, including a comparison of our bilevel controller with simpler conventional controllers