ABSTRACT
In this paper, we give exact description of null controllable regions for delta operator systems subject to actuator saturation. The null controllable region is in terms of a set of extremal trajectories of anti-stable subsystems. For the delta operator system with real eigenvalues or complex eigenvalues, the description is simplified to an explicit formula which is used to characterise the boundary of a null controllable region. The relations of null controllable regions are shown separately for continuous-time systems, discrete-time systems and delta operator systems. Two numerical examples are given to illustrate the effectiveness of the proposed techniques on null controllable regions.
Acknowledgments
The authors would like to thank the anonymous reviewers for their detailed comments which helped to improve the quality of the paper. The work was supported by the National Basic Research Program of China (973 Program) (2012CB720000). The work was also supported by the National Natural Science Foundation of China (61203023, 61225015, 61473024, 61573301), the Hebei Provincial Natural Science Fund (E2014203122, F2013203092), and the Ph.D. Programs Foundation of Ministry of Education of China (20111101110012).
Disclosure statement
No potential conflict of interest was reported by the authors.