Continuous-time quadratic regulators and pseudo-continuous-time quadratic regulators with pole placement in a specific region

A linear optimal quadratic regulator is developed, for optimally placing the closed-loop poles of multivariable continuous-time systems within the common region of an open sector, and the left-hand side of a line parallel to the imaginary axis in the complex s-plane, without explicitly utilising the eigenvalues of the open-loop systems. Also, a pseudo-continuous-time state-space method is developed, for finding the linear suboptimal quadratic regulator which suboptimally places the closed-loop poles of multivariable discrete-time systems within the common region of a circle, and the logarithmic spiral in the complex z-plane. An illustrative example is presented to demonstrate the effectiveness of the proposed procedures.