Flight control of a tilt duct uav with emphasis on the over actuated transition flight phase

Download

index.pdf

Date

2009

Author

Ünlü, Tuğba

Metadata

Show full item record

Item Usage Stats

275
views

241
downloads

In the thesis, automatic flight control system is designed for Tilt Duct Unmanned Aerial Vehicle (UAV). The vehicle is a Vertical Take-Off Landing (VTOL) type with two symmetric rotors on the wings, one aft rotor on the aft body. It behaves like a helicopter but with higher speeds in forward flight. Transition flight of the aircraft from hover to cruise or take-off to forward flight is the primary concern of the thesis study with the nonlinearities and instabilities encountered, together with the over-actuated controls in this mode. A nonlinear simulation code is developed including nonlinear equations of motion together with the nonlinear aerodynamics, environmental e ects, and rotor dynamics. Trim and linearization codes are also developed. Trim conditions for the transition flight phase are calculated for two different transition scenarios. Linear controllers are developed and nonlinear controller is designed for the transition mode. Nonlinear controller uses the state dependent Ricatti equation SDRE approach by using extended linearization. Two loop approach is used in order to increase controllability. In the inner loop, attitude rates are fed back and SDRE approach is used to calculate the feedback gain matrix online. In the outer loop, vehicle attitude is controlled using the eigenvalue assignment. Blended inverse algorithm based control allocation method is used in control of the over-actuated transition phase. This algorithm is shown to be quite effective among different methods in not only generating necessary forces needed for the control, but also allocating with more control authority on the desired actuator.

Subject Keywords

Aerospace engineering., Aeronautical engineering.

URI

http://etd.lib.metu.edu.tr/upload/2/12611078/index.pdf
https://hdl.handle.net/11511/18896

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Flight control system design for an over actuated UAV against actuator failures Işık, Sinem; Tekinalp, Ozan; Department of Aerospace Engineering (2010) This thesis describes the automatic flight control systems designed for a conventional and an over actuated unmanned air vehicle (UAV). A nonlinear simulation model including the flight mechanics equations together with the interpolated nonlinear aerodynamics, environmental effects, mass-inertia properties, thrust calculations and actuator dynamics is created; trim and linearization codes are developed. Automatic flight control system of the conventional UAV is designed by using both classical and robust co...
Design and analysis of a mode-switching micro unmanned aerial vehicle Cakici, Ferit; Leblebicioğlu, Mehmet Kemal (SAGE Publications, 2016-12-01) In this study, design and analysis of a mode-switching vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) with level flight capability is considered. The design of the platform includes both multirotor and fixed-wing (FW) conventional airplane structures; therefore named as VTOL-FW. The aircraft is modeled using aerodynamical principles including post-stall conditions. Trim conditions are obtained by solving constrained optimization problems. Linear analysis techniques are utilized for trim ...
Aero-structural design and analysis of an unmanned aerial vehicle and its mission adaptive wing İnsuyu, Erdoğan Tolga; Şahin, Melin; Department of Aerospace Engineering (2010) This thesis investigates the effects of camber change on the mission adaptive wing of a structurally designed unmanned aerial vehicle (UAV). The commercial computational fluid dynamics (CFD) software ANSYS/FLUENT is employed for the aerodynamic analyses. Several cambered airfoils are compared in terms of their aerodynamic coefficients and the effects of the camber change formed in specific sections of the wing on the spanwise pressure distribution are investigated. The mission adaptive wing is modeled struc...
Structural design, analysis and composite manufacturing applications for a tactical unmanned air vehicle Soysal, Sercan; Kayran, Altan; Department of Aerospace Engineering (2008) In this study structural design, analysis and composite manufacturing applications for a tactical UAV, which was designed and manufactured in Aerospace Engineering Department of Middle East Technical University (METU), is introduced. In order to make an accurate structural analysis, the material and loading is modeled properly. Computational fluid dynamics (CFD) was used to determine the 3D pressure distribution around the wing and then the nodal forces were exported into the finite element program by means...
Flight simulation and control of a helicopter Erçin, Gülsüm Hilal; Tekinalp, Ozan; Department of Aerospace Engineering (2008) In this thesis the development of a nonlinear simulation model of a utility helicopter and the design of its automatic flight control system is addressed. In the first part of this thesis, the nonlinear dynamic model for a full size helicopter is developed using the MATLAB/SIMULINK environment. The main rotor (composed of inflow and flapping dynamics parts), tail rotor, fuselage, vertical stabilizer, horizontal stabilizer of the helicopter are modeled in order to obtain the total forces and moments needed f...

Citation Formats

T. Ünlü, “Flight control of a tilt duct uav with emphasis on the over actuated transition flight phase,” M.S. - Master of Science, Middle East Technical University, 2009.