Minimum-Norm Pole Placement in Sampled-Data Systems

There is a need for low order, limited ouput feedback controllers for sampled-data systems. Closed-loop pole placement, with some constraints, is found to be achievable by the use of periodic, piecewise-constant output feedback. The norm of the feedback gains can be minimized using Sylvester´s equation and a secant search method. A simple expression for the gradient of the norm is derived using Kronecker products.