Single-input Control Systems Research Articles

On single input controllability for infinite dimensional linear systems

Given a controllable linear system { A, B} where A is a Volterra operator, there exists a vector b in the range of B such that { A, b} is controllable. The case where A is a convolution operator on L 2(0, ∞) is discussed and an example is given where a controllable system is not replaceable by a single input controllable system.

Analysis of combined integral pulse frequency and pulse-width modulated feedback systems†

An attempt is made in this paper to study the effect of Combined Integral Pulse Frequency and Pulse Width Modulation (CPM) on single-input and single-output control systems. The decision function, the pulse-width factor and the pulse amplitude (or the gain of the linear plant) are the parameters which influence the time response and their effect on such systems has been investigated. A step-by-step procedure is devised to construct the phase trajectory of such a system and it is shown that for an Integral Pulse Frequency Modulated (IPFM) system the hyperplane which the phase trajectory intersects is a particular case of the present one. Analysis of the phase trajectory of a second-order system by this procedure reveals that instability and asymptotic stability in the largo are exhibited by such systems. This paper is also concerned with the study of stability of CPM systems using quasi-describing function and application of this technique reveals that these systems present a limit tumulus, a phenomenon wh...