Showing papers by "Cédric Join published in 2007"
27 Jun 2007
TL;DR: In this paper, the authors presented new and efficient methods for numerical differentiation, i.e., for estimating derivatives of a noisy time signal, via convincing numerical simulations, by the analysis of an academic signal and by the feedback control of a nonlinear system.
Abstract: We are presenting new and efficient methods for numerical differentiation, i.e., for estimating derivatives of a noisy time signal. They are illustrated, via convincing numerical simulations, by the analysis of an academic signal and by the feedback control of a nonlinear system.
174 citations
TL;DR: This work extends previous works on model-free control to switched nonlinear SISO systems and yields PID-like regulators which ensure practical stability, utilizing new algebraic methods for numerical differentiations.
28 citations
TL;DR: In this paper, a flatness-based approach to fault tolerant control is proposed, which uses the recently published algebraic derivative estimation method for the estimation of those output derivatives that are necessary for determining intermittent actuator faults.
25 citations
10 Sep 2007
TL;DR: In this paper, a modified re-covery/trajectory control system is proposed to reduce the energy spent to achieve desired closed-loop performance by considering a reconfigurable reference input when performance degradation occurs due to faults in actuators dynamics.
Abstract: The prospective work reported in this paper explores a new approach in order to enhance the performance of an Active Fault Tolerant Control System. This novel technique is based on a modified re-covery/trajectory control system which considered a reconfigurable reference input when performance degradation occurs on system due to faults in actuators dynamics. The added value of this work is to reduce the energy spent to achieve desired closed-loop performance. This work is justified by the need of maintaining in dynamical way a reliable system. The feasibility of this work is illustrated using a three-tank system for slowly varying reference inputs corrupted by actuators faults.
2 citations
01 Jan 2007
TL;DR: A global active methodology is defined in order to synthesize an additive optimal control input from fault detection and isolation results, which generates a robust residual by means of usual parity relations to detect and isolate faults on the system.
Abstract: This paper deals with the problem of integration of fault diagnosis and fault tolerant control modules. The main objective is to ensure a good behavior of the closed-loop system in the presence of faults and disturbances. To this aim, a global active methodology is defined in order to synthesize an additive optimal control input from fault detection and isolation results. More precisely, a robust residual is firstly generated by means of usual parity relations to detect and isolate faults on the system. Next, a fault accommodation procedure, based model following control scheme, is used to generate an additive control input according to the residual characteristics. The efficiency of this methodology is illustrated through an heating system benchmark.
1 citations
01 Jan 2007
TL;DR: A classical model-based controllers for Active Queue Management(AQM) routers supporting dynamic model of Transmission Control protocol (TCP) flows is developed and classical RED controller is adapted in order to take into account the network parameters variations.
Abstract: :
In this work a classical model-based controllers for Active Queue Management(AQM) routers supporting dynamic model of Transmission Control protocol (TCP) flows is developed. Using this model, an AQM control system using Random Early Detection (RED) controller is designed. In first part, the interconnection terms of TCP are simplified. Second part, the stability of the closed loop system is studied on the basis of a simplified Internet router model (Misra et al., 2000). In the proposed approach classical RED controller is adapted in order to take into account the network parameters variations. In the last part of the paper, the approach is validated using Matlab Simulation.