  We introduce a novel structured controller design for the electron beam
stabilization problem of the UK's national synchrotron light source. Because
changes to the synchrotron will not allow the application of existing control
approaches, we develop a novel method to diagonalize the multi-input
multi-output (MIMO) system. A generalized singular value decomposition (GSVD)
is used to simultaneously diagonalize the actuator response matrices, which is
applicable to an arbitrary number of actuator dynamics in a cross-directional
setting. The resulting decoupled systems are regulated using mid-ranged control
and the controller gains derived as a function of the generalized singular
values. In addition, we exploit the inherent block-circulant symmetry of the
system. The performance of our controller is demonstrated using simulations
that involve machine data.
