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A systematic design procedure suited to integrate rigid body and aeroelastic control objectives within the mixed sensitivity framework is proposed for a two-degrees-of-freedom control configuration. It is based on a modal representation and combines stability augmentation, structural mode control and maneuver demand in a single linear parameter-varying (LPV) controller. To demonstrate applicability,...
Learning and repetitive control are powerful instruments in handling recurring disturbances. Repetitive control properly handles constantly repeating variations, while iterative learning control is well-equipped when it comes to handling event triggered deviations. Neither controller is well equipped to adequately deal with repetitive disturbances, which are only present during limited, but varying,...
Addressing the load simulating issue of the helicopter manipulation booster under high-frequency dynamic load to be superimposed on large static load, this paper has developed an electro-hydraulic loading system for this type of the load. The mathematical model of the electro-hydraulic loading system is firstly established. Then, a hybrid suppression scheme is proposed to eliminate the extraneous...
In this paper, we extend Robust Bode loop-shaping design methods to open-loop unstable and non-minimum phase SISO systems.We show how loop-shaping controller design may be performed using either the Contoured Robust Controller Bode (CRCBode) plots or a new Robust Bode plot based on the Youla parametrization of all stabilizing controllers (QBode). We demonstrate the effectiveness of these approaches...
In this paper, a supply chain composed of one supplier and one retailer is studied. The supply chain is coordinated under the revenue-sharing contract in static case. Disruption makes the price sensitivity coefficient change. In integrated supply chain, the supplier needs to adjust the retail price if demand deviation is in certain range. The supplier needs to adjust the retail price and the production...
The present paper discusses the design of a discrete-time proportional-integral-derivative (PID) control system for a first-order plus dead-time model. The optimal parameters for the desired robustness of the PID control system are determined by using the maximum value of the sensitivity function. We optimized the load-disturbance or the set-point performance in order to achieve the specified robustness...
In this paper we propose a multi-objective optimization approach for the tuning of one degree-of-freedom proportional-integral-derivative controllers where both the trade-off between the servo and regulation operation modes and the trade-off between performance and robustness are considered. After having quantified the loss of performance that occurs when robustness is taken into account in the optimal...
This paper describes an image tamper detection and recovery method based on self-embedding dual watermarking. The watermark in the proposed method is a down-sampled version of an original image (cover image). Two identical watermarks are then decomposed into bit planes and embedded into the least-significant bit (LSB) plane of the cover image. This dual watermarking strategy ensures a robust performance...
In this paper, we propose an overview of the Fault Detection and Diagnosis concept as the detection and characterisation of a hidden information as usually addressed in Data Hiding approaches. In fact, on one side Fault Detection and Diagnosis is generally studied as the detection and characterization of changes (abrupt or not) in a signal describing the behavior of a system. On the other side, data-hiding...
In this paper we propose a technique and an objective performance metric, that we denote "area-metric", for the analysis and overall comparison and characterization of FTIR spectral response sensitivity-improvement performances of strained-layer superlattice (SLS) 3μm-5μm MWIR single photo detectors, enhanced with microsphere lenses of different dielectric material structures and sizes....
This paper studies the H2/H∞ approach to control the Internet traffic. We are interested in using the H2 formulation to improve transient performances in addition to maintaining the robust performance offered by the formerly used H∞ formulation. In this controller, the closed-loop dynamics are monitored and controlled by the sensitivity functions along with their associated weight functions. The LMI...
Robust control aims to account for model uncertainty in design. Traditional methods for robust control typically assume knowledge of hard bounds on the system frequency response. However, this does not match system identification procedures which typically yield statistical confidence bounds on the estimated model. Recent work in this area has proposed a procedure for obtaining a better match between...
The main objective of this contribution is a new development of the continuous-time generalised predictive control (CGPC) resulting in a Youla-based CGPC design procedure for both minimumphase and nonminimum-phase uncertain SISO systems. The derived design procedure consists of two steps. In the first step nominal stability and nominal performance of the control system are established by using a fully...
In this paper the problem of fault isolation in non linear systems is considered. Faults are formulated as parameter changes and a novel definition of fault detent ability is introduced. This connects a fault with its effect on the output of the system under consideration. Based on this definition, a practical way to test the fault detectability is introduced. In this context, a general result about...
This paper deals with the design of robust digital controllers by the combined pole placement / sensitivity function shaping method. It shows that the design problem can be formulated and solved as a convex optimization problem. Specifications like dominant closed-loop poles or integration controller action may be introduced just as well as other fixed parts for the controller. The method is illustrated...
This paper describes the application of H«, design synthesis to the control of a mechanical stabilisation system with uncertain and time-varying first structural resonance frequency. The class of mechanisms under investigation is described and the design aims and classical control techniques currently employed are presented. It is shown that both an increase in performance and robustness to mechanism...
The problem considered in this paper is the robust controller design for the focus control loop of DVD-video drive. For low-speed players, is known that this problem can be solved by means of simple lead-lag regulators. For high-speed players the disturbance rejection is more difficult problem than for CD players because of higher performance requirements. The control scheme proposed here is based...
This paper shows that, in the SISO case, optimal mixed-sensitivity 2-norm controllers are also solutions to the optimal robust disturbance attenuation problem (ORDAP). That is, they deliver robust sensitivity reduction despite unstructured uncertainty at the optimal level. We explicitely identify one set of ORDAP weights for which such a controller is ORDAP optimal. Functional analysis duality theory...
Integral action is required in many controllers in order to solve real world problems. Modeling errors and disturbances are examples of issues that can be dealt with by using controllers with integral action. This paper explores the use of disturbance observers to introduce integral action into an output feedback controller. In particular, the proposed solution is generalized to include the case of...
PID controller design is considered where optimal controller parameters are found with constraint on maximum sensitivity and robustness with regard to cone bounded static nonlinearity acting on the plant.
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