scholarly journals A reactive control system for a partially guided small sounding rocket

2019 ◽  
Vol 304 ◽  
pp. 07011
Author(s):  
Cristian Emil Constantinescu
Keyword(s):  
Flight Control ◽  
Sounding Rocket ◽  
Reactive Control ◽  
Dead Weight ◽  
Sounding Rockets ◽  
Stability And Control ◽  
Second Stage ◽  
Upper Stage ◽  
The Stability ◽  
And Control

Most small sounding rockets are unguided vehicle. Stability is solved aerodynamically using fins and/or rapidly spinning the vehicle and trajectory is determined by the azimuth and elevation of the launch pad as the rocket usually fly a gravity turn. Access to upper atmosphere usually require two or three stages and the presence of fins on the upper stages inflict a penalty on the stability of the launcher in the start configuration. The paper presents a modification made to an existing launcher suggested by the need to add dead weight for stability when flying small payloads. By eliminating the fins from the second stage and using a RCS for active stability and control of the upper stage several opportunities arise: the aerodynamic configuration is simpler and the stability in the start configuration improved, drag is reduced a bit, non-gravity turn evolutions are possible and special payload requested attitudes (mainly orienting a camera towards ground) are conceivable. Of course, this require a new OBC with enhanced sensors and new navigation and flight control algorithms.

Flight control and flight experiments of a tilt-propeller VTOL UAV

2018 ◽  
Vol 40 (8) ◽  
pp. 2454-2465 ◽  
Author(s):  
Zafer Öznalbant ◽  
Mehmet Ş. Kavsaoğlu
Keyword(s):  
Flight Control ◽  
Equations Of Motion ◽  
Control Methods ◽  
Stability And Control ◽  
Flight Mode ◽  
Aerial Vehicle ◽  
The Stability ◽  
And Control ◽  
Pitch Tilt ◽  
Fixed Pitch

The purpose of this work is to present a study on the stability and control of an unmanned, fixed wing, vertical take-off and landing aerial vehicle. This airplane is driven by a fixed-pitch tilt-propeller system with the capability of vertical take-off and landing as well as conventional flight. The novelty of the vehicle is the use of a fixed-pitch propeller system instead of variable-pitch tilt-rotors. There are three flight modes: vertical, transitional and conventional flight modes. Each flight mode has different dynamic characteristics. Therefore, these modes each need dedicated flight control methods. In this paper, the equations of motion are generated by modelling the aerodynamic and propulsion forces and moments. After performing trim condition calculations, longitudinal stability characteristics are investigated for each flight mode. The control methods are described for vertical, transitional and conventional flight modes. Stability augmentation systems, which consist of proportional and proportional/integral controller, are applied. A number of flight tests, including vertical, transitional and conventional flights, have been successfully performed with a prototype aircraft.

Some Stability and Control Aspects of Airframe/Propulsion System Interactions on the YF-12 Airplane

1974 ◽  
Vol 96 (3) ◽  
pp. 820-826 ◽  
Author(s):  
D. T. Berry ◽  
G. B. Gilyard
Keyword(s):  
Static Stability ◽  
Propulsion System ◽  
Jet Propulsion ◽  
Stability And Control ◽  
The Stability ◽  
And Control ◽  
Large Aircraft

Airframe/propulsion system interactions can strongly affect the stability and control of supersonic cruise aircraft. These interactions generate forces and moments similar in magnitude to those produced by the aerodynamic controls, and can cause significant changes in vehicle damping and static stability. This in turn can lead to large aircraft excursions or high pilot workload, or both. For optimum integration of an airframe and its jet propulsion system, these phenomena may have to be taken into account.

scholarly journals Advanced Modelling of KF Implemented Flying Wing

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Widanalage Dakshina ◽  
Thiwanka Fernando
Keyword(s):  
Extreme Condition ◽  
Flow Conditions ◽  
Ongoing Research ◽  
Stability And Control ◽  
Advanced Phase ◽  
Landing Gears ◽  
Two Phases ◽  
The Stability ◽  
And Control ◽  
Base Design

This research carries out the advanced phase in correlation with the previous published design of KF Implemented Flying Wing. At the primary stage the basic design was considered under omission of non-static components and turbulent conditions. At this stage the simulations have taken a step ahead with improved flow conditions and advanced modeling of the design. As per the design aspects the engines, pylons, landing gears and shape improvements were done with solid modeling. Due to the computational limitations this was divided in to two phases as cruising conditions with non-static components and further studies to be carried out in Takeoff and Landing conditions with extended landing gears. Under the stability and control conditions a separate research is being carried out in achieving the optimum capability. Propfan engine selected for extreme condition evaluations. The implementations were made without disrupting the base design which was presented in phase one basic simulation carried out prior to this. The simulation results deemed to be promising for the first stage as well as the effect of new components. The secondary target areas are to be carried out in further ongoing research as well

scholarly journals Designing Stipulated Gains of Aircraft Stability and Control Augmentation Systems for Semiglobal Trajectories Tracking

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Mostafa Y. B. Elshabasy ◽  
Yongki Yoon ◽  
Ashraf Omran
Keyword(s):  
Control Method ◽  
Simple Procedure ◽  
Operating Conditions ◽  
Stability And Control ◽  
Wide Range ◽  
Flight Envelope ◽  
The Stability ◽  
Classical Control ◽  
And Control ◽  
Aircraft Stability And Control

The main objective of the current investigation is to provide a simple procedure to select the controller gains for an aircraft with a largely wide complex flight envelope with different source of nonlinearities. The stability and control gains are optimally devised using genetic algorithm. Thus, the gains are tuned based on the information of a single designed mission. This mission is assigned to cover a wide range of the aircraft’s flight envelope. For more validation, the resultant controller gains were tested for many off-designed missions and different operating conditions such as mass and aerodynamic variations. The results show the capability of the proposed procedure to design a semiglobal robust stability and control augmentation system for a highly maneuverable aircraft such as F-16. Unlike the gain scheduling and other control design methodologies, the proposed technique provides a semi-global single set of gains for both aircraft stability and control augmentation systems. This reduces the implementation efforts. The proposed methodology is superior to the classical control method which rigorously requires the linearization of the nonlinear aircraft model of the investigated highly maneuverable aircraft and eliminating the sources of nonlinearities mentioned above.

Sign in / Sign up

Export Citation Format

Share Document