Ana Teruko Yokomizo Watanabe

In this article, we combine fault diagnosis and prognosis to generalize the notion of safe controllability of discrete-event systems. To do so, we reformulate the notions of safe diagnosability, prognosability, safe controllability by diagnosis, and safe controllability by prognosis in the context of strings. Moreover, we combine these notions to introduce the concept of safe controllability by diagnosis or prognosis, or simply DP-safe controllability. We show that a language can be DP-safe controllable even if it is not safe controllable either only by diagnosis or only by prognosis. Thus, the DP-safe controllability can be considered a generalization of the safe controllability concept found in the literature. If a DES is DP-safe controllable, to achieve fault tolerance using an active approach, reconfiguration actions could be forced based not only on online fault diagnosis, but also on online fault prognosis. Thus, our approach outperforms the previous ones, since it provides additional control options to keep the system away from forbidden zones and to switch from the nominal supervisor to a postfault-detection supervisor designed to achieve postfault performance objectives. Necessary and sufficient conditions for DP-safe controllability are presented and an example is used to illustrate the introduced concepts.

The objective of this work is to show the operation of a system that allows monitoring, controlling and configuring a wireless household-electric network. The user interface of this system is done through a personal digital assistant (PDA). Initially, the wireless communication was established by the Bluetooth protocol. It was used a hardware module which provided the communication between the PDA and the microcontroller embedded in the household-electric. In the next step, it will be implemented modifications in the hardware and firmware of the appliance, to implement functions using a microcontroller with integrated ZigBee protocol. In the implementation of the user interface, it is being used the JAVA programming language, which allows the portability of the interface to the Palm, windows and symbian operational systems used in PDAs and smartphones.