Fault-tolerant Control Systems

Fault tolerant control offers enhanced availability and reduced risk of safety hazards when component failure and other unexpected events occur in a controlled plant. Fault-tolerant control merges several disciplines into a framework with common goals. The fault-tolerant properties are obtained through on-line fault detection and isolation, automatic condition assessment and calculation of appropriate remedial actions. The final step is activation of the necessary actions through software. The actions to accommodate a fault cover a wide range of possibilities and underlying theory. Appropriate re-tuning can sometimes suffice, estimation of a signal replacing a measurement from a faulty sensor is needed in other events, and some cases require complex re-configuration or on-line redesign. The basis for a remedial action is always detection of an undesired event and the correct assessment of the situation through isolation of the fault. Analysis of the effects of the not-normal conditions, and the possible remedial actions, is a truly complex problem in most cases. The paper gives an overview of recent progress in theory and methods to analyze and develop fault-tolerant control systems. Fault propagation analysis and severity assessment are shown to be the basic means to evaluate safety and dependability. Following this, an analysis of structure will disclose available redundancy and possibilities to recover from faults in the system. These overall tools lead to requirements to fault detection and isolation. Fault detection theory has been the subject of intensive study for two decades. Nevertheless, the requirements from the use in fault-tolerant architectures have caused new challenges and further development. This paper focus on recent results in overall design methods for fault-tolerant control systems. An example shows how the different concepts are used and illustrates the benefits from active fault tolerance as compared to a traditionally designed control architecture.

[1]  W. M. Wonham.  A control theory for discrete-event systems , 1988 .

[2]  Christos G. Cassandras,et al.  Introduction to the Modelling, Control and Optimization of Discrete Event Systems , 1995 .

[3]  Ron J. Patton,et al.  Fault-Tolerant Control: The 1997 Situation , 1997 .

[4]  Charlotte Pii Lunau.  A Reflective Architecture for Process Control Applications , 1997, ECOOP.

[5]  F. Thau.  Observing the state of non-linear dynamic systems† , 1973 .

[6]  P. Frank,et al.  Deterministic nonlinear observer-based approaches to fault diagnosis: A survey , 1997 .

[7]  Alan S. Willsky,et al.  A survey of design methods for failure detection in dynamic systems , 1976, Autom..

[8]  M. Staroswiecki,et al.  A formal approach to reconfigurability analysis application to the three tank benchmark , 1999, 1999 European Control Conference (ECC).

[9]  M. Blanke,et al.  Identification of a class of nonlinear state-space models using RPE techniques , 1986, 1986 25th IEEE Conference on Decision and Control.

[10]  Mogens Blanke,et al.  A Ship Propulsion System Model for Fault-tolerant Control , 1998 .

[11]  Paul M. Frank,et al.  Robust Component Fault Detection and Isolation in Nonlinear Dynamic Systems using Nonlinear unknown Input Observers , 1991 .

[12]  Jan Lunze,et al.  Qualitative modelling of linear dynamical systems with quantized state measurements , 1994, Autom..

[13]  Jan Lunze,et al.  An example of fault diagnosis by means of probabilistic logic reasoning , 1997 .

[14]  Marcel Staroswiecki,et al.  Models and languages for the interoperability of smart instruments , 1996, Autom..

[15]  M. Staroswiecki,et al.  ANALYTICAL REDUNDANCY IN NON LINEAR INTERCONNECTED SYSTEMS BY MEANS OF STRUCTURAL ANALYSIS , 1989 .

[16]  Vincent Cocquempot,et al.  Residual Generation for the Ship Benchmark Using Structural Approach , 1998 .

[17]  Janos Gertler,et al.  Fault detection and diagnosis in engineering systems , 1998 .

[18]  R. Patton,et al.  Observer Design for a Class of Non-Linear Systems , 1997 .

[19]  William R. Perkins,et al.  Design of reliable control systems , 1992 .

[20]  Jan M. Maciejowski,et al.  Reconfigurable Flight Control During Actuator Failures Using Predictive Control , 1999 .

[21]  Dingli Yu,et al.  A bilinear fault detection observer , 1996, Autom..

[22]  Mogens Blanke,et al.  Fault-tolerant control systems — A holistic view , 1997 .

[23]  Mogens Blanke,et al.  FAULT MONITORING AND RE-CONFIGURABLE CONTROL FOR A SHIP PROPULSION PLANT , 1998 .

[24]  R. Sengupta,et al.  An Optimal Control Theory for Discrete Event Systems , 1998 .

[25]  R. Rajamani,et al.  A systematic approach to adaptive observer synthesis for nonlinear systems , 1997, IEEE Trans. Autom. Control..

[26]  Mogens Blanke,et al.  Consistent design of dependable control systems , 1996 .

[27]  Rolf Isermann,et al.  Process fault detection based on modeling and estimation methods - A survey , 1984, Autom..

[28]  Jakob Stoustrup,et al.  Fault detection for nonlinear systems - a standard problem approach , 1998, Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171).

[29]  Mogens Blanke,et al.  A Ship Propulsion System as a Benchmark for Fault-tolerant Control , 1997 .

[30]  Jakob Stoustrup,et al.  Integrating Control and Fault Diagnosis: A Separation Result , 1997 .

[31]  Christian W. Frei,et al.  Recoverability viewed as a system property , 1999, 1999 European Control Conference (ECC).

[32]  S. A. Bøgh,et al.  Fault Tolerant Control Systems , 1997 .