The geometrical coupling between strain and twist in double helices is investigated. Overwinding, where strain leads to further winding, is shown to be a universal property for helices, which are stretched along their longitudinal axis when the initial pitch angle is below the zero-twist angle (39.4◦). Unwinding occurs at larger pitch angles. The zero-twist angle is the unique pitch angle at th...

Reset controllers are commonly used to smooth the transient response of systems. We use this technique to improve a standard baseline pitch controller for offshore wind turbines (WTs). The introduction of this strategy enhances the overall performance of the WT. In particular, the fore-aft and side-to-side accelerations of the WT tower are significantly reduced, whilst a steadier power output i...

Positioning systems include different control functions for automatic positioning and guidance of marine vessels by means of proper action of the thruster and propeller devices. These may be controllable pitch propeller (CPP) with fixed speed, controllable speed with fixed pitch propeller (FPP), or controllable pitch and speed in combination. The positioning controller computes commanded forces...

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Plane perching on a wire has been demonstrated with success in laboratory conditions by [Cory & Tedrake, 2008]. The present paper focuses on designing a controller for a small wall landing glider. We use a simulator and a reinforcement learning algorithm in a coarsely discretized state-space to design an optimal control for the landing. Analysis of this policy allows us to deduce a simpler clos...

–In this paper, first the transfer function and block diagram model of a flight path rate demand autopilot (two loop) in pitch plane has been shown and then its state model has been developed. Then state feedback controller has been designed. Thereafter both of Luenberger and Das & Ghosal Observers (DGO) are implemented for the above said two loop autopilot. Finally the system, observer and sta...

This paper presents a comparative analysis of two intelligent reference learning techniques to achieve better performance of pitch control of an aircraft. Fuzzy Model Reference Learning Controller (FMRLC) and Radial Basic Function Neural Controller (RBFNC) are designed for pitch control of a FOXTROT fighter aircraft. These controllers utilize a learning mechanism, which observes the plant outpu...

This paper aims to solve the fault tolerant control problem of a wind turbine benchmark. A hierarchical controller with model predictive pre-compensators, a global model predictive controller and a supervisory controller is proposed. In the model predictive pre-compensator, an extended Kalman Filter is designed to estimate the system states and various fault parameters. Based on the estimation,...

MODELING AND CONTROL OF A DOUBLY-FED INDUCTION GENERATOR FOR WIND TURBINE-GENERATOR SYSTEMS Xin Jing, M.S.E.E Marquette University, 2012 Wind energy plays an increasingly important role in the world because it is friendly to the environment. During the last decades, the concept of a variable-speed wind turbine (WT) has been receiving increasing attention due to the fact that it is more controll...