This book, written by two major figures in adaptive control, provides a wealth of material for researchers, practitioners, and students. While some researchers in adaptive control may note the absence of a particular topic, the book‘s scope represents a high-gain instrument. It can be used by designers of control systems to enhance their work through the information on many new theoretical developments, and can be used by mathematical control theory specialists to adapt their research to practical needs. The book is strongly recommended to anyone interested in adaptive control.

Adaptive Control

WE found, on experimental grounds in Article I, that the field of air‐flow past a short body of low resistance shape, such as an aerofoil, comprises two dissimilar parts: (a) a thin boundary layer enveloping the body and dominated by viscous effects, and (b) a motion outside the boundary layer in which viscosity is much less important. It will be remembered that in the external motion occur the large pressure changes, which, transmitted through the boundary layer, account for nearly all the lift and for part of the drag. These pressures we observed to be calculable from the velocities without appreciable error by Bernoulli's equation. In the present Article we confine attention to this external flow, assuming it to be steady, incompressible, and inviscid. Its dependence upon (a), already discussed to some extent, we ignore; the boundary layer is conceived to be everywhere very thin, so that the only role it plays is to allow of relative velocity at the surface of the body. The assumptions made, excepting that of incompressibility, will appear drastic, and it will not be surprising if some of our deductions prove discordant with experimental fact. Nevertheless, they lead to a theory which finds many applications and uses in real fluid motion, and, in particular, gives an intimate view of aerofoil flow that is very close to the truth. It is convenient to develop our reasoning in analytical terms and for simplicity to restrict the flow to two dimensions (Article 1, §5). But the engineer will find special scope in this part of aerodynamics for graphical methods in the solution of particular problems.

Aerodynamics for Engineers

In this paper we propose two modeling procedures for wind speed simulation. These procedures could be implemented on the structure of a wind turbine simulator during studies concerning stand-alone or hybrid wind systems. The evolution of a horizontal wind speed has been synthesized taking into account two components. The medium- and long-term component is described by a power spectrum associated to a specific site. The turbulence component is assumed to be dependent on the medium- and long-term wind speed evolution. It is considered as a nonstationary process. Two simulation methods for this component, using rational and nonrational filters are proposed. In both procedures, the turbulence model is defined by two parameters, which are either obtained experimentally, or adopted a priori, according to information from the considered site. Numerical results and implementation aspects are also discussed.

https://ieeexplore.ieee.org/iel5/8949/28458/01270996.pdf

Large band simulation of the wind speed for real time wind turbine simulators

Nonlinear dissipative devices in structural vibration control: A review

A review of modelling and analysis of morphing wings

Design, experimental investigation, and nonlinear flight dynamics with atmospheric disturbances of a fixed-wing micro air vehicle

The aerodynamic design optimisation of a Micro Air Vehicle (MAV) wing is performed to obtain the optimal anti-symmetric wing twist distribution for the roll control of the MAV’s wing instead of using conventional ailerons. This twist distribution should produce minimum induced drag and achieve a better roll response. The implementation of several anti-symmetric load distributions such as the half lemniscates and the Horten distributions is studied leading to an initial solution for the optimal distribution that could achieve better roll requirements. Multhopp’s method based on Prandtl’s classical lifting line theory is used for the determination of the spanwise load distribution required during the optimisation process. The optimisation process is based on the modified feasible directions gradient based optimisation algorithm implemented in the optimisation system, VisualDOC, given by Dr. Garret Vanderplaats. The proposed optimisation process is applied to the ‘BARQ’developed MAV which has successful flight in July 2009.

Optimal wing twist distribution for roll control of MAVs

Purpose – The purpose of this paper is to show the merit of using mission information in tuning the controller gains for Stewart manipulator instead of the generic inputs previously developed in literature.Design/methodology/approach – The paper introduces two optimization techniques based on mission information. The first technique, a partial‐information technique, uses gain scheduling that applies different controllers for different mission tracks. The second technique, a full‐information technique uses a single robust controller by considering the full mission data. For demonstrating these techniques' feasibility, a nonlinear numerical simulation for a Stewart manipulator was built and tested using a generic mission. This mission consists of two piecewise trajectories (tracks). The proposed techniques were compared with one of the previous optimization techniques in literature, no‐information technique, in which a step response is used to search for optimal controller gains without any information abou...

Mission‐based optimal control of Stewart manipulator

In this paper, a new technique for modeling the forward kinematics of a Stewart manipulator is presented based on a predicted squared error cost function. Initially, the inverse kinematics model was introduced in detail for seeding the regression points. Genetic algorithms were then employed to search for optimal model structure from a set of candidate regression predictors. The proposed technique provides a significant reduction in the expenses of memory and computation compared to the traditional Taylor series expansion model. Such reduction increases the suitability of the model for a task space control application of the Stewart manipulator.

Optimal Forward Kinematics Modeling of Stewart Manipulator Using Genetic Algorithms

The aerodynamic shape optimisation of a micro air vehicle (MAV) wing is performed to obtain the basic wing geometrical characteristics which produce the maximum range and endurance requirements. Multhopp’s method based on Prandtl’s classical lifting line theory is used for the determination of the spanwise load distribution required during the optimisation process. The obtained lift and drag characteristics are used for the derivation of the range and endurance equations of an electrically driven micro air vehicle. The optimisation process is based on the modified feasible directions gradient based optimisation algorithm. Results are validated using wind tunnel measurements showing very good agreement. Results are also compared with solutions to the Navier-Stokes equations obtained with ANSYS-CFX finite elements using different turbulence models. These include the k-e and the shear stress transport (SST) models as well as the Reynolds stress model.

Gamal M. El-Bayoumi

Papers

Design, experimental investigation, and nonlinear flight dynamics with atmospheric disturbances of a fixed-wing micro air vehicle

Optimal wing twist distribution for roll control of MAVs

Mission‐based optimal control of Stewart manipulator

Optimal Forward Kinematics Modeling of Stewart Manipulator Using Genetic Algorithms

Aerodynamic shape optimisation, wind tunnel measurements and CFD analysis of a MAV wing