This paper carries out the mathematical modeling, simulation, and control law design for a quadrotor with variable-pitch propellers. The use of variable-pitch propeller for thrust variation instead of RPM regulation facilitates generation of negative thrust, thereby augmenting the rate of change of thrust generation amenable for aggressive maneuvering. Blade element theory along with momentum t...

This paper focuses on the development of a wind gust load alleviation control system for implementation in very flexible aircraft. The gust load alleviation system is designed using Linear Quadratic Gaussian (LQG) control techniques, and it is based on a nonlinear model of the coupled rigid-body and elastic modes of a very flexible aircraft. The nonlinear model contains the dynamics of the airc...

iii Nomenclature h altitude, ft ˙ h vertical velocity, ft/sec K fnt scale factor for lift from jet-induced fountain p roll rate, deg/sec q pitch rate, deg/sec r yaw rate, deg/sec T CN cruise nozzle thrust, lb T LF lift-fan thrust, lb T LN lift-nozzle thrust, lb T R rise time, sec V airspeed, knots V ej equivalent jet velocity ratio V x ground speed, ft/sec V y lateral velocity, ft/sec β sidesli...

In recent years, individual pitch control has been developed for wind turbines, with the purpose of reducing blade and tower loads. Such algorithms depend on reliable sensor information. The azimuth angle sensor, which positions the wind turbine rotor in its rotation, is quite important. This sensor has to be correct as blade pitch actions should be different at different azimuth angle as the w...

This paper suggests two methods to calculate the gains of a proportional-Integral pitch angle controller for a 5 MW wind turbine. The first method is analytical and the second one is based on simulation. Firstly, the power coefficient characteristics for different pitch angles are calculated. Secondly, the output powers vs. rotor speed curves from cut-in to cut-out wind speeds are simulated. Th...

This paper discusses the performance of various intelligent control schemes in extracting maximum wind power using doubly fed induction generator (DFIG). Intelligent control scheme such as fuzzy, neuro-fuzzy, and genetic algorithm based fuzzy controllers are applied for pitch control of DFIG based wind generation system. Wind generation system with eight numbers of identical 1.5MW wind generato...

This study investigated the influence of thread pitch, helix angle, and compactness on micromotion in immediately loaded implants in bone of varying density (D2, D3, and D4). Five models of the three-dimensional finite element (0.8 mm pitch, 1.6 mm pitch, 2.4 mm pitch, double-threaded, and triple-threaded implants) in three types of bone were created using Pro/E, Hypermesh, and ABAQUS software....

The requirements in pitch angle control of winged body are a very fast response with as less oscillation as possible. The oscillation can damage the equipments which are carried within the body. The main problem to cope with is in relatively fast and oscillatory dynamics of the rocket and slow actuators and sensors. We solve the problem by using predictive approach. The main idea of this approa...