Failure Diagnosis on Discrete Event Systems

Kechida, Sihem; Debbache, Nasr Eddine

doi:10.3844/ajassp.2005.1547.1551

Cited by 3 publications

(2 citation statements)

References 1 publication

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“…Not much has been done in this area in the research front. Many have done a lot of work on prognostics as (Kechida and Debbache, 2005) done. But, enhancing TTL has remained an untouched area.…”

Section: Problem Statementmentioning

confidence: 99%

Enhancement of Total Technical Life of Aero Planes

Balachandran

Suresh²,

Vasudevan

et al. 2014

Journal of Computer Science

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Government of India spends most of its income towards strengthening the Army, Air Force and Navy. Out of the amount spent for this, about 80% of money is spent on technology advancement and maintenance. We are coming in particular now about the Air Force and its fighter jets along with other flying machines as well. Taking Mirage-2000 as an instance, the complete project has been planned to be carried out. The total technical life i.e., effective flying time for a fighter plane is generally around 5000 h of flying/25 years approximately. In between, there can be services done at periodic intervals. Means, it will be permitted to fly up to 2000 h, then servicing can be done with which further flying can be permitted. The point here is, even if a flight has not flown for 2000 h, but reached 12 years of time frame, it has to be serviced, which is definitely under utilization of the machine. Also a particular flight can be flown for 2000 h. well before time, say 8 years; even then the servicing has to be carried out. A flight might have been subjected to tough flying (G-Conditions) conditions in a short span of time. In such case, it undergoes tough wear and tear through which more fatigue is also possible. In this case this machine has to be given more attention as it has been used under extreme conditions. On the other side of the coin, for the same flying hours, another flight which had flown under straight/study conditions will also get the same treatment. It is not fair to treat a guy who is working hard and a guy who has not done that! Few researchers have worked on understanding and even proposing fault diagnositcs. But, there is a lot more to do in cost savings point of view. This study aims at bringing a solution, which has an embedded system in place which would fetch all the critical information during flight and with which optimum usage can be obtained and thereby increasing the effective flying time of the flight through which we get better results economically, technically and avoiding over maintenance. This will eventually find out a way to exploit the aircraft more effectively with cutting down the unnecessary cost.

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Section: Problem Statementmentioning

confidence: 99%

Enhancement of Total Technical Life of Aero Planes

Balachandran

Suresh²,

Vasudevan

et al. 2014

Journal of Computer Science

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“…Today, the diagnosis of the industrial systems draws the attention of several researchers (Athamena et al, 2007;Kechida and Debbache, 2005;Hakiki et al, 2006). Many methods are published for the diagnosis various classes systems.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of a Robust Multiobserver for the Estimation of Unknown Inputs Using the Piecewise Quadratic Functions

Maherzi¹

2010

American Journal of Applied Sciences

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Problem statement:The estimation of states and the unknown inputs of a nonlinear system described by a multimodel are done by a multiobserver. The stabilization of the multiobserver calls upon uses both quadratic and no quadratic functions of Lyapunov. Although the stabilization using the quadratic approach is interesting from the point of view implementation, the step showed its limits for the multimodel. However, the problem paused by the quadratic method lies in the obligation to satisfy several LMI with respect to the same Lyapunov matrix P, these results are shown very conservative. Approach: To reduce the conservatism of the quadratic approach we propose another approach which is exclusively based on Lyapunov piecewise quadratic functions. The conditions obtained by the stabilization of the multiobserver are expressed in term of matrix inequalities with constraints on the matrices rank. Results: The estimation of both states and unknown inputs of a multimodel using the quadratic approach per pieces leads to results less conservative than the quadratic approach. Academic examples illustrate the robustness of the piecewise quadratic approach. Conclusion: In this article we proposed new sufficient conditions of stability of a multiobserver able to the estimation of states and unknown inputs of a nonlinear system describes by a multimodel subjected to the influence of the unknown inputs. The study in was carried out by considering two approaches. The first approach is based on Lyapunov quadratic functions; it is significant to note the great difficulty in finding satisfying results by this approach for the multimodel systems. For this reason we proposed an approach based on piecewise quadratic functions which led to interesting results (proposition 1) and less conservative than the quadratic approach. The conditions suggested in this article concern both the multiobserver stabilization and the estimation of states and the unknown inputs of a multimodel with measurable variables of decision (µξ(k)). The synthesis of a multiobserver with no measurable variables of decision is not approached. This point can constitute an interesting prospect for this study.

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