Pitch Command Research Articles

Feasible Control for Optimum Power Generation in a Small Power System

A pitch controller is developed for a wind turbine in a small wind-diesel power system. The proposed controller regulates wind converted power to meet the constraints of system frequency and power limit of wind turbine. Static model of wind turbine and diesel governor response are used to determine the desired power command and the respective pitch command is derived by variable gain integral control so that the error between actual and desired power is minimized. Small wind-diesel power system of Koshikijima island in Japan is considered for model studies and the effectiveness of the proposed controller is proved by computer simulation based on actual data of wind speed.

Online identification and control of linearized aircraft dynamics

An approach for online identification and control that requires weaker excitation than the existing approaches based on least-squares schemes and closed-loop systems is examined. It uses multiple-objective optimization theory to resolve the conflict between identification and controller performance as they compete for the only available resource, the inputs to the aircraft. The approach is applied to a longitudinal model of a representative linearized high-performance aircraft model. Simulation results compare the final controller with a conventional gain-scheduled pitch command augmentation system. It is demonstrated that by allowing some control input to be given to the identification process, the controller's overall performance is improved. >

Computer simulation of an ideal fluid, constant depth, fluidic controlled submersible vehicle

This study was carried out to find a mathematical model that represents uniform potential incompressible steady flow over a two-dimensional blunt body that has mass flow injected into the main flow at a predetermined location on the body geometry. It has application as a towed submersible vehicle. A change in depth of the vehicle is sensed by a depth valve which introduces a pitch command to the fluidic device. The control activates a thruster, thereby restoring the vehicle to its desired depth. The fluidic control part of the vehicle, however, is not investigated in the study. The shape of the vehicle (a streamline) is obtained by a combination of the elemenatry flow patterns, namely, uniform flow and a distribution of sources and sinks. The computer is used to determine the best combination possible by adjusting the elementary flow patterns and the positions of the control jet on the vehicle. Some numerical examples have been made. It is seen that a suitable mathematical model of a towed vehicle to operate automatically at constant depth can be designed.

Manual terrain-following system development for a supersonic fighteraircraft.

The requirements for a low-level, high-speed penetration to a target are briefly reviewed. The design constraints on the pitch command system are then evolved, and the effects of load factor, flight path angle, and type of command display on system design and performance are presented. During the incorporation of manual terrain-following systems into two different versions of the F-4 airplane, fixed base flight simulators were utilized to optimize system design as well as to finalize system parameters. As a result of these studies, each system was modified to provide improved performance and to obtain a command display acceptable to the pilot. A scoring technique that allows optimization of the system parameters without tailoring the system to a particular terrain type was developed. An ideal profile is generated for the terrain being used, and the actual flight path is compared to the ideal. Therefore, comparison will show how well the system allowed the pilot to follow the terrain within the design constraints and will indicate the type of system deficiency which must be removed in order to bring the flight path closer to the optimum.