Eigenstructure assignment in reconfigurable control systems (original) (raw)

Reconfigurable flight control for robust transient response

Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2013

When a control surface fails during aircraft flying, reconfigurable control system with new configuration aims to use the other available control surfaces and attempts to preserve the design properties of the original system. Restoring transient response is particularly important when transition from damaged to healthy configuration takes place. In this article, a new design procedure for robust transient response of the reconfigured system is presented. A linear algebraic formulation for right eigenstructure assignment in state feedback format is derived. A system of linear equations for the controller is solved. Reconfigurable control using an F-18 model is illustrated.

An Optimization Approach to Control Reconfiguration

1999

An optimization algorithm for the problem of control reconfiguration in response to operating condition changes or abrupt system component failures is presented here. The algorithm utilizes a version of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) optimization method of conjugate directions. The algorithm provides an output feedback controller that not only stabilizes the new/impaired system, when possible, but also preserves much of the dynamics of the original/unfailed system. The design is such that the closed-loop system is robust with respect to inevitable uncertainties/modelling errors on the state-space matrices of the impaired system. The algorithm is applied to an aircraft longitudinal control system, for which two severe cases of failure are considered, first the loss of an actuator and then the loss of a sensor in addition to the actuator loss.

Reconfigurable control allocation applied to an aircraft benchmark model

2008 American Control Conference, 2008

In this paper, a study of reconfigurable control allocation applied to a realistic and nonlinear aircraft model is presented. A pseudo-inverse based method for reconfigurable control allocation has been investigated in an ADMIRE (Aero-Data Model In Research Environment) aircraft benchmark model. Partial loss of control effectiveness type faults have been implemented. Simulation results show satisfactory performance for accommodating the partial loss of control effectiveness in control effectors.

Optimized Reconfigurable Control Design for Aircraft using Genetic Algorithm

In this study, we propose a Genetic Algorithm (GA) based modular reconfigurable control scheme for an over-actuated non-linear aircraft model. The reconfiguration of the flight controller is achieved for the case of control surface faults/failures using a separate control distribution algorithm without modifying the base-line control law. The baseline Multi-Input Multi-Output (MIMO) Linear Quadratic Regulator (LQR) is optimized using GA to produce desired moment commands. Then, a GA based weighted pseudo-inverse method is used for effective distribution of commands between redundant control surfaces. Control surface effectiveness levels are used to redistribute the control commands to healthy actuators when a fault or failure occurs. Simulation results using ADMIRE aircraft model show the satisfactory performance in accommodating different faults, which confirm the efficiency of optimized re configurable design strategy.

An automatic redesign approach for restructurable control systems

IEEE Control Systems Magazine, 1985

paper presents an ap-_ -proach to the automatic redesign of flight control systems for aircraft that have suffered one or more control element failures. The procedure is based on linear quadratic (LQ) design techniques, and produces a control system that maximizes a measure of feedback system performance subject to a bandwidth constraint.

New method of parametric eigenvalue assignment in state feedback control

IEE Proceedings - Control Theory and Applications, 1994

A new method is described for the assignment of eigenvalues of closed-loop plants in linear time-invariant multivariable systems. The parameterisation of controllers is based on the derivation of zero eigenvalue assignment by implementation of vector companion forms. This method is computationally very attractive and can be used for optimisation of the feedback matrix which assigns the closed-loop eigenvalues (from the set of real, complex conjugates or even those of the open-loop system) to the desired locations. A numerical example is presented to illustrate some advantages of this new explicit parameterisation of the controller gain matrix. Paper 1157D (C8), first received Zlst lune 1993 and in revised form 8th

Multimodel-based flight control system reconfiguration control in the presence of input constraints

Journal of Control Theory and Applications, 2010

In this paper, an active fault accommodate strategy is proposed for the plant in the presence of actuator fault and input constraints, which is a combination of a direct adaptive control algorithm with multiple model switching. The μmodification is introduced in the model reference architecture to construct the adaptive controller. The proof of stability is based on the candidate Lyapunov function, while appropriate switching of multiple models guarantees asymptotic tracking of the system states and the boundedness of all signals. Simulation results illustrate the efficiency of the proposed method.

Performance of Reconfiguration Structures Based on the Constrained Control

Proceedings of the 17th IFAC World Congress, 2008, 2008

An approach is proposed for reconfigurable control structure design to obtain a system tolerant to state-variable sensor faults. The method is based on discrete-time constrained control design techniques for linear systems with state constraints, defined by linear equalities. Degradation in steady state performance is dealt with fixing that state variable which is associated with sensor fault to zero value. Since that control design can be viewed as a specific pole-assignment problem, reconfigured LQ control structures, as well as stabilizing reconfiguration structure are introduced.

Optimisation approach to robust eigenstructure assignment

IEE Proceedings - Control Theory and Applications, 1999

A systematic optimisation approach to robust eigenstructure assignment for control systems with output feedback is presented. The proposed scheme assigns the maximum allowable number of closed-loop eigenvalues to desired locations, and determines the corresponding closedloop eigenvectors as close to desired ones as possible. Additionally, the stability of the remaining closed-loop eigenvalues is guaranteed by the satisfaction of an appropriate Lyapunov equation. The overall design is robust with respect to time-varying parameter perturbations. The approach is applied to a literature example, where it is shown to capture the shape of the desired transient response.