A sparse controller structure with small closed-loop roundoff noise gain

This paper investigates the roundoff noise effect in the digital controller on the closed-loop output for a discrete-time feedback control system. Based on a polynomial parametrization approach, a sparse controller structure is derived. The performance of the proposed structure is analyzed by deriving the corresponding expression of closed-loop roundoff noise gain and the problem of finding optimized sparse structures is solved. A numerical example is presented to illustrate the design procedure and the performance of the proposed structure compared with those of some existing well-known structures.