Comparison of two model based residual generation schemes for the purpose of fault detection and isolation applied to a pneumatic actuation system

This paper discusses research carried-out on the development and validation (on a real plant) of a parity-equation and Kalman filter based fault detection and isolation (FDI) system for a pneumatic actuator. The parity and Kalman filter equations are formulated and used to generate residuals that, in turn, are analysed to determine whether faults are present in the system. Details of the design process are given and the experimental results are compared. The results demonstrate that both approaches can successfully detect and isolate faults associated with the sensors, actuators (servo-valves and piping) and the pneumatic cylinder itself. The work is part of a BAE SYSTEMS sponsored project to demonstrate advanced control and diagnosis concepts on an industrial application

Development of a Fault Tolerant Actuation System- Modelling and Validation

It is generally accepted that incorporating so-called ‘smart’ control and monitoring technologies can improve the reliability and availability of industrial systems. ‘Smart’ control can be defined as making full use of all the measured, inferred and a priori information that is available from a system. In general terms, the idea is that system level knowledge can be developed and used to check sensors for problems, to detect and identify faults as they develop and, where appropriate, to re-configure the controller(s) to accommodate plant or sensor faults until repair can be effected. To-date success, in terms of real industrial applications of the more advanced techniques, has been limited. Hence, demonstrators are needed. The work described in this paper is part of an on going project aimed at demonstrating these “smart” concepts on a Stewart-Gough platform comprising six pneumatic actuators. To-date the research has focussed on specifying the demonstrator system and developing and validating models of the pneumatic system. This is probably the most important step in designing a fault tolerant actuation system – as the model is the foundation of the other algorithms

Model-based fault detection and control design – applied to a pneumatic Stewart-Gough platform

This paper discusses research carried-out on the development and validation of a model-based fault detection and isolation (FDI) system for a pneumatically actuated Stewart platform arrangement. The FDI scheme is based on combining parity-equation and Kalman filter based techniques. The parity and Kalman filter equations are formulated and used to generate residuals that, in turn, are analysed to determine whether faults are present in the system. Details of the design process are given and the experimental results are compared. The results demonstrate that both approaches when combined can successfully detect and isolate and in some cases accommodate faults associated with the sensors, actuators (servo-valves and piping) and the pneumatic system itself. The work is part of a BAE SYSTEMS’ sponsored project to demonstrate advanced control and diagnosis concepts on an industrial application

Modelling requirements for the design of active stability control strategies for a high speed bogie

The paper presents the findings of a study on active stability control and simulation for a railway bogie vehicle. For control design a planview partial railway vehicle model is described. This is a simplified model derived from research experience and appropriate modelling, and a frequency domain analysis illustrates the problems associated with system instability. A multi-body dynamics software, SIMPACK1, is used to generate a detailed non-linear full vehicle model for simulation and control assessment. Model order reduction methods, both empirically and analytically based, are used to simplify the linear model generated from SIMPACK for further system analysis and control designs based upon the complex model. Comparisons between the simplified plan-view model and the exported reduced-order model are presented

Application of fault detection and isolation to a pneumatic actuation system

This paper discusses research carried-out on the development and validation (on real plant) of a parity-equation based fault detection and isolation (FDI) system for a pneumatic actuator. A mechanistic model of the system is developed and validated in order to derive suitable parity equations for the pneumatic actuation system. The parity equations are then formulated and used to generate residuals that, in turn, are analysed to determine whether faults are present in the system. Details of the design process are given and the experimental results demonstrate that the approach can successfully detect and isolate faults associated with the sensors, actuators (servo-valves and piping) and the pneumatic cylinder itself. The work is part of a BAE SYSTEMS’ sponsored project to demonstrate advanced control and diagnosis concepts on a Stewart-Gough platform

Systems approach for health management design: A simple fuel system case study

This paper presents the first of two case studies conducted in 2009, to evaluate a concept for specifying and designing a Health Management System (HMS). This first case study made use of a representative Unmanned Aerial Vehicle fuel system. Conflicting information requirements relating to the health of the fuel system were defined for a given stakeholder (Fuel System Maintenance Engineer). Following a Failure Modes and Effects Analysis of the fuel system, the concept was applied under two scenarios (with and without additional sensors), to specify associated HMS designs. These two designs were then compared to consider how well each design addressed the conflicting requirements. In addition, attributes such as weight, cost and power were also associated to the underlying HMS sensors. The attribute values were aggregated to the requirements level and demonstrated a new approach to designing and evaluating alternative HMS designs. The case study demonstrated that although this was a simple evaluation, the underlying concept has shown considerabl

Fault Tolerant Control for EMS systems with sensor failure

The paper presents a method to recover the performance of an EMS (Electromagnetic suspension) under faulty air gap measurement. The controller is a combination of classical control loops, a Kalman estimator and analytical redundancy (for the air gap signal). In case of a faulty air gap sensor the air gap signal is recovered using the Kalman filter and analytical redundancy. Simulations verify the proposed sensor Fault Tolerant Control (FTC) method for the EMS system

MAGLEV suspensions - a sensor optimisation framework

In this paper, a systematic framework for optimised sensor configurations is implemented via H∞ Loop Shaping Procedure. The optimisation framework, gives the sensor sets that satisfy predefined user criteria and the preset constraints required for the MAGnetic LEVitated suspension performance via evolutionary algorithms. The scheme is assessed via appropriate simulations for its efficacy

Sensor optimisation via H∞ applied to a MAGLEV suspension system

In this paper a systematic method via H∞ control design is proposed to select a sensor set that satisfies a number of input criteria for a MAGLEV suspension system. The proposed method recovers a number of optimised controllers for each possible sensor set that satisfies the performance and constraint criteria using evolutionary algorithms

Sensor optimisation via H∞ applied to a MAGLEV suspension system

In this paper a systematic method via H∞ control design is proposed to select a sensor set that satisfies a number of input criteria for a MAGLEV suspension system. The proposed method recovers a number of optimised controllers for each possible sensor set that satisfies the performance and constraint criteria using evolutionary algorithms