Abstract. In this paper the problem of designing a single actuator control for a class of systems is addressed. The existence of such control is studied and several ways for designing such control are provided. The results depend either on the rational canonical form or on the Jordan structure associated with the matrix which characterizes the system dynamics. The constructed control laws can be employed in the design of minimum cost controllers for a large variety of systems.Keywords: Controllability • rational Frobenius form • Jordan form
IntroductionDynamical system theory aims to characterize systems via time-evolution models [1,2]. Such characterization can be employed for performing two fundamental and dual tasks in dynamical system theory: on the one hand, the estimation of system's internal state from the measurement of accessible system outputs, defining the so called observation problem; on the other hand, the modification of system's internal state via the injection of appropriate system inputs, defining the so called control problem [3,4,5]. These problems have been thoroughly studied in the literature, specially for linear systems [6,7,3]. A fundamental issue when dealing with the control and observation of dynamical systems is that of the controllability and observability of the system, i.e. under which conditions a system can be controlled or observed. Such conditions are well established for the case of linear time invariant (LTI) dynamical systems of the form ^ = Ax(t) +Bu(t), y(t) = Cx(t), where Many standard control problems have to deal with matrices A and B which are prestablished by the system dynamics and/or actuator restrictions. In this context, the controllability condition serves as a test on the existence of control laws with some specific properties. On the other hand, some applications or theoretical problems consider the possibility of arbitrarily selecting the number and location of the actuators. Hence, matrix B may become a design element, and the controllability condition may serve as a design criterion. In