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In this paper we design and analyze a full-information H∞ controller to in order to reduce the wake meandering behind a wind turbine. The low frequency instability that causes wake meandering can cause unsteady mechanical loads on the downstream turbines resulting in early onset of material fatigue. Controlling the wake meandering in a wind farm can therefore reduce maintenance costs. The control...
Wind turbines in a wind farm operate individually to maximize their own power regardless of the impact of aerodynamic interactions on neighboring turbines. There is the potential to increase power and reduce overall structural loads by properly coordinating turbines. To perform control design and analysis, a model needs to be of low computational cost, but retains the necessary dynamics seen in high-fidelity...
A method to reduce the dynamic order of linear parameter-varying (LPV) systems in grid representation is developed in this paper. It approximates balancing and truncation by an oblique projection onto a dominant subspace. The approach is novel in its use of a parameter-varying kernel to define the direction of this projection. Parameter-varying state transformations in general lead to parameter rate...
Wind turbines in a wind farm are operated individually to maximize their own power regardless of the impact of aerodynamic interactions on neighboring turbines. There is the potential to increase power and reduce overall structural loads by properly coordinating the turbines. To perform control design and analysis, a model needs to be of low computational complexity but retain the necessary dynamics...
Wind turbines are typically operated to maximize their own performance without considering the impact of wake effects on nearby turbines. There is the potential to increase total power and reduce structural loads by properly coordinating the individual turbines in a wind farm. The effective design and analysis of such coordinated controllers requires turbine wake models of sufficient accuracy but...
This paper considers the performance of a gain scheduled flight control law for an aeroelastic aircraft. A nonlinear aeroelastic model of the Rockwell B-1 Lancer is used as the application example. Gain scheduling via interpolation of point designs is the predominant method used in industry to develop a full-envelope flight control law. Certification and validation of these nonlinear gain-scheduled...
Model-based fault detection methods can be used to reduce the size, weight, and cost of safety-critical aerospace systems. However, the implementation of these methods is based on models. Therefore, disturbance and model uncertainty must be considered in order to certify the fault detection system. This paper considers the worst-case false alarm probability over a class of stochastic disturbances...
A modern hard disk drive uses a dual-stage actuator to read/write data on a track with width less than 100nm. The dual-stage actuator requires an advanced controller to achieve high performance on millions of hard disk drives. This paper presents a numerical algorithm utilizing convex optimization to create an uncertainty model, for the purpose of synthesizing a robust controller, from a set of experimental...
Model-based fault detection methods have the potential to reduce the size, weight, and cost of safety-critical aerospace systems. One obstacle to the application of these methods is a lack of appropriate tools to efficiently certify their reliability. This paper focuses on the false alarm analysis of a general fault detection scheme. The main difficulty of the false alarm analysis is the time-correlations...
This paper considers the local performance analysis of uncertain polynomial systems. A method for estimating an upper bound of the local L2 → L2 gain is presented. The gain upper bound condition is formulated in terms of a dissipation inequality that incorporates an integral quadratic constraint to model the uncertainty. For polynomial systems, the dissipation inequality can be verified using sum-of-squares...
Geometric fault detection and isolation filters are known for having excellent fault isolation properties. However, they are generally assumed to be sensitive to model uncertainty and noise. This paper proposes a robust model matching method to incorporate model uncertainty into the design of geometric fault detection filters. Several existing methods for robust filter synthesis are described to solve...
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