Mireille Bayart

Models and languages for the interoperability of smart instruments

This paper presents the functions of intelligent instruments in the frame of real-time process operating systems, and shows that they have the same functional structure as the system itself. Thus smart-instruments-based distributed architectures can be built, provided that they present interoperability properties. Some working groups and projects whose aim is to define interoperable field instruments are presented. The last part of the paper develops a smart-instrument generic description.

Models and Languages for the Interoperability of Smart Instruments

Abstract The paper presents the functions of intelligent instruments in the frame of Real Time Process Operating Systems and shows that they have the same functional structure as the system itself. Thus, smart instruments based distributed architectures can be built provided they present interoperability properties. Some working groups and projects whose aim is to define interoperable field instruments are presented. In the last part, the paper proposes a smart instrument generic description.

Hierarchical Data Validation in Control Systems using Smart Actuators and Sensors

Abstract The distribution of the intelligence among all the components of the automation system allows to consider them as a connexion of a number of intelligent objects which produce or consume informations via a communication system associated with global management rules. The exchanges between components require the validation of the transmitted or received data. The functional validation is based on the physical or analytical redundancy of available information which are transmitted via a direct link or via a field bus. It is achieved by a Fault Detection and Isolation algorithm. This paper presents a hierarchical decomposition of this algorithm and shows how it can then be implemented into smart components.

Dependable Distributed Computer Control Systems: Analysis of the Design Step Activities

Abstract The paper sets the problem of the design step in the context of production automated systems and presents a modeling of this activity. The design step is located after the specification one and before the strictly speaking implementation one. The problem is to be sure that the partitioning of the specified application into intercommunicating modules and the allocation of the modules to computing assets and communication systems will satisfy the different constraints expressed in the end-user requirements, and in the specification.

Fault Detection and Isolation and Mode Management in Smart Actuators

Abstract This paper presents the generic functional architecture of a smart actuator. It mainly addresses the decomposition level relative to Fault Diagnosis and Isolation and details the mode management module.

Robust control of wind energy conversion systems

A robust control algorithm for wind turbines subjected to a wide range of wind variation, grid disturbance and parameter uncertainties is presented. The algorithm utilizes fuzzy systems based on “Takagi-Sugeno” (TS) fuzzy models to approximate nonlinear systems. TS fuzzy systems are classified into three families based on the input matrices and a robust controller synthesis procedure is given for each family. This algorithm combines the merits of: (i) the capability for dealing with non-linear uncertain systems; (ii) the powerful Linear Matrix Equalities (LME) approach to obtain control gains. The control scheme is tested for different real profiles of wind speed pattern and provides satisfactory results.

An extended qualitative multi-faults diagnosis from first principles I: Theory and modelling

This paper is part I of a two part effort that is intended to present a framework of multi-faults diagnosis. Reiter [14] has proposed a consistency-based approach for multi-faults diagnosis. We extend his theory to deal with the dynamic and continuous systems and offer a necessary assumption and a formal demonstration. Multi-faults diagnosis is a partially observable problem because there is usually not enough information about faults. So the STRIPS, a classic technique of automated planning, is chosen to build the system model. It provides the reasoning ability for the multi-faults diagnosis when diagnosis is formalized as reasoning from effects to causes with causal knowledge.

An extended qualitative multi-faults diagnosis from first principles II: Algorithm and case study

This paper continues to present the framework of multi-faults diagnosis from the preceding paper. There are two main contributions in this part. One is aimed at developing a new diagnostic process for continuous and dynamic system and its corresponding consistency-checking module. This diagnostic process and its consistency-checking module are all based on the models defined by STRIPS actions. The other is that the fault models are introduced into the consistency-checking module for preventing the impossible diagnoses. Moreover, the STRIPS can qualitatively define the fault models without requiring detail and precise knowledge about faulty components.

Sensor and actuator placement with dependability constraints and a cost criterion

This paper deals with the design of control systems. A method to optimize the instrumentation is presented and uses financial cost and dependability as criteria. This method is based on a structural model that describes qualitatively the different relations that link the physical variables. By analyzing this model, it is possible to obtain the different ways to estimate the unknown variables in function of the measurements provided by the sensors. The fault tolerant level is used to specify the dependability and to fix the number of failures that can induce the unavailability of the control system. Fixing this number for a given variable corresponds to the required number of different ways that allows its estimation in the structural model. In this context, the optimization consists in finding the instrumentation that satisfies the fault tolerant level constraints with the lowest financial cost. The two main contributions of this paper are first a clear formalization of the optimization problem that takes into account the costs of devices and specified fault tolerant level and second an extension of the structural model in order to take into account different operating modes and their specific features.

FDI of smart actuators using bond graphs and external models

Abstract In the paper, we interest to smart actuators. External model has been defined in order to improve behavioural of actuator in presence of failures. The external model requires information from Fault Detection and Isolation algorithms. To complete the information providing to the users, we associate bond graph methodology to the external model in order to complete the information with physical knowledge. The objectives are to obtain self-diagnosis intelligent actuators. In the final paper, the proposed description will be applied to an intelligent actuator which integrates a control valve, a pneumatic servomotor and a positioner