Diagnosis of Hybrid Systems: Part 1-Diagnosability

Abstract-In this paper, we investigate fault diagnosis and diagnosability in hybrid systems modeled by hybrid automata. Generally, in hybrid systems, there are discrete sensors generating discrete outputs available at the discrete-event system representation of the system and continuous sensors generating continuous outputs available at the continuous dynamics. We assume that there is a bank of residual generators (using continuous sensors) designed for the continuous dynamics of the system. We present a hybrid diagnosis approach in which faults are diagnosed by integrating the information generated by the residual generators and the information at the discrete-event system representation of the system. We investigate the diagnosability of faults in the hybrid diagnosis framework

Fault Diagnosis in Discrete-Event Systems: Framework and Model Reduction

A state-based approach for on-line passive fault diagnosis in systems modelled as finite-state automata is presented. In this framework, the system and the diagnoser (the fault detection system) do not have to be initialized at the same time. Furthermore, no information about the state or even the condition (failure status) of the system before the initiation of diagnosis is required. The design of the fault detection system, in the worst case, has exponential time complexity. A model reduction scheme with polynomial time complexity is introduced to reduce the computational complexity of the design. 1 Introduction Fault detection systems are of paramount importance in aerospace, manufacturing and process industries. This is due to the crucial role they play in protecting life and property, and in increasing operational time and productivity. Solving diagnostic problems for complex systems is a complicated task requiring a reliable, systematic approach. As a result, fault diagnosis has..

Supremum Operators and Computation of Supremal Elements in System Theory

. Constrained supremum and supremum operators are introduced to obtain a general procedure for computing supremal elements of upper semilattices. Examples of such elements include supremal (A; B)-invariant subspaces in linear system theory and supremal controllable sublanguages in discrete-event system theory. For some examples, we show that the algorithms available in the literature are special cases of our procedure. Our iterative algorithms may also provide more insight into applications; in the case of supremal controllable subpredicate, the algorithm enables us to derive a lookahead policy for supervisory control of discrete-event systems. Keywords. Discrete-event systems, linear systems, lattice theory, supervisory control, partition, supremal elements, supremum operators AMS subject classifications. 93B, 68Q20 1 Introduction In system theory, we sometimes encounter lattice structures [2], [5]. Examples are the lattice of equivalence relations in the theory of sequential machi..

Control of (max,+)-linear systems minimizing delays

International audienceIn this paper, we develop a new control technique for discrete event dynamic systems subject to synchronization phenomena. We propose a feedback controller for (max, +)-linear systems which delays input events as little as possible while constraints on internal or output events are satisfied. The synthesis is mainly based on new results about fixed points of antitone (i.e., order reversing) mappings