Eigenstructure Assignment Techniques Research Articles

Explicit hidden coupling terms handling in gain-scheduling control design via eigenstructure assignment

This paper presents a novel method for the design of gain-scheduled output feedback controllers in the presence of hidden coupling terms, which naturally arise when endogenous signals are used as scheduling parameters. In this case, the controller gains vary with respect to system variables, leading to inner loops between the system and the linearized gain-scheduled controller dynamics. Such effects, also known as parasitic feedbacks, are inherently difficult to handle in classic gain-scheduling control design and are often omitted, which might result in performance degradations or even destabilization of the closed-loop system. This paper shows how such a pitfall can be avoided through the application of self-scheduling and eigenstructure assignment techniques. In this context, the main contribution of the present work is the extension of eigenstructure assignment-based self-scheduling techniques for explicit hidden coupling terms handling. The viability of the proposed method is illustrated through a pitch-axis missile autopilot benchmark problem.

A Pitch-Depth Bottom Following Controller for AUVs using Eigenstructure Assignment

This paper addresses the problem of bottom following by the MARES Autonomous Underwater Vehicle, and presents the derivation of a controller able to cope with the peculiarities of such problem. In specifc, the main requirement for the controller is the existence of no overshoot both in the depth and pitch outputs of the system. The existence of such time-domain requirements motivates the use of Eigenstructure Assignment techniques in the formulation of the controller. Simulation results obtained with a dynamic model of the MARES AUV are presented and discussed, indicating the validity of the proposed approach.

On the Linear Constrained Regulation Problem for Continuous-Time Systems

In this paper the regulation problem for linear continuous-time systems by linear state-feedback under linear state and/or control constraints is investigated. This problem, named the Linear Constrained Regulation Problem, has been extensively studied when the regulation concerns an equilibrium situated in the interior of the domain of admissible states. In this paper the case when the desired equilibrium state is on the boundary of the domain of admissible states is considered. The tools used for the analysis and design of this kind of control problems are the conditions of positive invariance of polyhedral sets, Lyapunov-like polyhedral functions, LMI methods and eigenstructure assignment techniques.

A Review on Eigenstructure Assignment Methods and Orthogonal Eigenstructure Control of Structural Vibrations

This paper provides a state-of-the-art review of eigenstructure assignment methods for vibration cancellation. Eigen- structure assignment techniques have been widely used during the past three decades for vibration suppression in structures, especially in large space structures. These methods work similar to mode localization in which global vibrations are managed such that they remain localized within the structure. Such localization would help reducing vibrations more effectively than other methods of vibration cancellation, by virtue of confining the vibrations close to the source of disturbance. The common objective of different methods of eigenstructure assignment is to provide controller design freedom beyond pole placement, and define appropriate shapes for the eigenvectors of the systems. These methods; however, offer a large and complex design space of options that can often overwhelm the control designer. Recent developments in orthogonal eigenstructure control offers a significant simplification of the design task while allowing some experience-based design freedom. The majority of the papers from the past three decades in structural vibration cancellation using eigenstructure assignment methods are reviewed, along with recent studies that introduce new developments in eigenstructure assignment techniques.

A Review on Eigenstructure Assignment Methods and Orthogonal Eigenstructure Control of Structural Vibrations

This paper provides a state-of-the-art review of eigenstructure assignment methods for vibration cancellation. Eigenstructure assignment techniques have been widely used during the past three decades for vibration suppression in structures, especially in large space structures. These methods work similar to mode localization in which global vibrations are managed such that they remain localized within the structure. Such localization would help reducing vibrations more effectively than other methods of vibration cancellation, by virtue of confining the vibrations close to the source of disturbance. The common objective of different methods of eigenstructure assignment is to provide controller design freedom beyond pole placement, and define appropriate shapes for the eigenvectors of the systems. These methods; however, offer a large and complex design space of options that can often overwhelm the control designer. Recent developments in orthogonal eigenstructure control offers a significant simplification of the design task while allowing some experience-based design freedom. The majority of the papers from the past three decades in structural vibration cancellation using eigenstructure assignment methods are reviewed, along with recent studies that introduce new developments in eigenstructure assignment techniques.

능동비행제어기술에 기반한 자동차 횡방향 제어

In this paper, a lateral vehicle control using the concept of control configured vehicle(CCV) is presented. The control objectives for the lateral dynamics of a vehicle include the ability to commend a chosen variable without significant motion change in other specified variables. The analysis techniques fur decoupling of the aircraft motions are utilized to develop vehicle lateral control with advanced mode. Vehicle lateral dynamic is determined to have the steering input and control torque input. The additional vehicle modes are also defined to using CCV concept. We use right eigenstructure assignment techniques and command generator tracker to design a control law for an lateral vehicle dynamics. The desired eigenvectors are chosen to achieve the desired decoupling(i.e., lateral direction speed and yaw rate). The command generator tracker is used to ensure steady-state tracking of the driver's command. Finally, the developed design is utilized by using the lateral vehicle dynamic with four wheel.

Lateral vehicle control based on active flight control technology

In this paper, a lateral vehicle control using the concept of control configured vehicle (CCV) is presented. The control objectives for the lateral dynamics of a vehicle include the ability to follow a chosen variable without significant motion change in other specified variables. The analysis techniques for decoupling of the aircraft motions are utilized to develop vehicle lateral control with advanced mode. Vehicle lateral dynamic is determined to have the steering input and control torque input. The additional vehicle modes are also defined to using CCV concept. We use right eigenstructure assignment techniques and command generator tracker to design a control law for an lateral vehicle dynamics. The desired eigenvectors are chosen to achieve the desired decoupling (i.e., lateral direction speed and yaw rate). The command generator tracker is used to ensure steady-state tracking of the driver’s command. Finally, the developed design is utilized by using the lateral vehicle dynamic with four wheel.

Estabilização de sistemas descritores por realimentação de saídas via subespaços invariantes

Considera-se o problema da existência e do cálculo de uma matriz de realimentação de saídas que estabiliza fortemente um sistema descritor linear. Os resultados apresentados baseiam-se no conceito de (C,A,E,B)-invariância e de sua caracterização algébrica através de equações acopladas de Sylvester e de equações acopladas de tipo Lyapunov. Apresentam-se algoritmos para o cálculo da matriz de realimentação de saídas, baseados em posicionamento de autoestrutura ou na solução de desigualdades e igualdades matriciais lineares. Os resultados e algoritmos apresentados generalizam resultados anteriores propostos para sistemas lineares clássicos e para classes particulares de sistemas descritores lineares.

Reconfigurable control system design using eigenstructure assignment: static, dynamic and robust approaches

New approaches to design static and dynamical reconfigurable control systems are proposed based on the eigenstructure assignment techniques. The methods can recover the nominal closed-loop performance after a fault occurrence in the system, in the state and output feedback designs. These methods are capable of dealing with order-reduction problems that may occur in an after-fault system. The problem of robust reconfigurable controller design, which makes the after-fault closed-loop system insensitive as much as possible, to the parameter uncertainties of the after-fault model is considered. Steady state response of the after-fault system under the unit step input is recovered by the means of a reconfigurable feed-forward compensator. The methods guarantee the stability of the reconfigured closed-loop system in the case of output feedback. For the faulty situations, in which the order of the pre-fault and after-fault closed-loop systems are the same, sufficient regional pole assignment conditions for the reconfigured system are derived. Finally, simulation results are provided to show the effectiveness of the proposed methods for two aircraft models.

On Disturbance Decoupled Observers for Linear Descriptor Systems

Conditions for the existence of disturbance decoupled minimal-order observers for a class of descriptor systems are presented. Basically, these conditions are associated to the solution of a generalized Sylvester equation under a constraint that describes the disturbance decoupling of the estimated state. Thus, under some structural conditions of the considered descriptor system, a sequence of coordinate transformation allows to define a reduced-order normal system. Both eigenstructure assignment and regional pole placement techniques can be applied to solve the constrained reduced-order Sylvester equation. For regional pole placement, a LMI technique is proposed and a illustrative numerical example i reported.

Robust MIMO control-system design using eigenstructure assignment and QFT

An approach to robust control design for a multi-input/multi-output (MIMO) plant using eigenstructure assignment (EA) and quantitative feedback theory (QFT) is presented and applied to the design of a lateral flight control system. EA techniques are introduced to give an initial feedback control design for the nominal plant model, providing decoupling between the multiple control channels. The QFT method for single-input/single-output (SISO) plants is used to obtain robust stability under the given plant-parameter uncertainties. Detailed designs are conducted with both the proposed EA/QFT approach and the direct MIMO QFT approach. The design results demonstrate the good performance and features of the proposed EA/QFT approach that may be achieved.

Eigenstructure Assignment Technique for Damage Detection in Rotating Structures

In this work, the detection and identification of damage in a helicopter rotor blade is considered. An eigenstructure assignment technique is developed using measured modal test data and a finite element model of the blade to detect and characterize the extent of damage in the system. Previous eigenstructure assignment techniques have not attempted to consider the centrifugal and gyroscopic forces found in rotating systems. Additional elemental stiffness matrix terms are generated for the inboard elements due to the centrifugal force caused by the mass of the outboard elements. This force creates an enhanced sensitivity of the eigenstructure to mass changes thereby leading to an improved damage detection capability. Feasibility of the methodology is demonstrated analytically on a finite element model of the TH-55A main rotor blade.

Output feedback variable structure control design

This paper describes a procedure for variable structure output feedback control (VSOFC) for a class of multivariable linear time-invariant systems. The equivalent control method of Utkin in the output feedback mode yields a reduced-order system exhibiting output feedback equivalent dynamics. Using the Kimura-Davison sufficient conditions for pole-placement using output feedback, a sufficient condition is derived to assign the eigenvalues of the 'reduced'-order system. The observability and controllability of the reduced system is discussed. Two switching surface design algorithms are introduced based on both a static output feedback and on an eigenstructure assignment techniques. A control design is discussed as well.