Abstract
Recently, the advancement of micro-computer and communication technologies makes it possible to construct a distributed control system. The distribution of the control system aims at not only fault-tolerance but also online maintenance and expansion. It is proposed for these objectives to give autonomy such that each controller can control its responsible control region even if some other controllers and their sensors fail or even before they are constructed. This property of the system is defined as autonomous controllability.
Necessary and sufficient conditions for autonomous controllability of a linear system with perfect information and with imperfect information are derived. Moreover, the difference between autonomous controllability and conventional controllability, which does not assume the failures and expansion of some controllers and their sensors, is clarified.
The problems to design a system satisfying autonomous controllability are how to divide the system, to make a simple and expandable structure and to allocate the control region to each controller. These problems are respectively resolved by weakly coupling condition among subsystems, uniform structure of each subsystem and state re-transformation method.
These discussions make it partially clear to relate control, reliability and expandability.
