Design and flight testing of manual nonlinear flight control laws

2011 ◽  
Author(s):  
Thomas Lombaerts ◽  
Gertjan Looye
Keyword(s):  
Flight Control ◽  
Flight Testing ◽  
Control Laws

Flight Simulator as a Tool for Flight Control System Synthesis and Handling Qualities Research

2009 ◽  
Vol 147-149 ◽  
pp. 231-236 ◽  
Author(s):  
Tomasz Rogalski ◽  
Andrzej Tomczyk ◽  
Grzegorz Kopecki
Keyword(s):  
Control System ◽  
Control Systems ◽  
Flight Control ◽  
Flight Simulator ◽  
Flight Control System ◽  
Aircraft Control ◽  
Flight Testing ◽  
Flight Tests ◽  
Control Laws ◽  
Handling Qualities

At the Department of Avionics and Control Systems problems of aeronautical control systems have been dealt with for years. Several different kinds of aeronautical control systems have been designed, prototyped and tested. These control systems are intended for general aviation aircraft and unmanned aircraft. During all research projects computer simulations and laboratory tests were made. However, since in some cases such tests were insufficient, in-flight tests were conducted leading to a series of reliable results. The in-flight tests were made with the use of M-20 Mewa aircraft (autopilot for a GA aircraft) and PZL-110 Koliber aircraft (control system for UAV and indirect flight control system for a GA aircraft). Nevertheless, in-flight testing is very expensive and problematic. To avoid some problems appearing during in-flight tests and their preparation, a simulator – which is normally used for professional pilot training – can be used. The Aviation Training Center of the Rzeszów University of Technology possesses the ALSIM AL-200 MCC flight simulator. We have started preparing this simulator for the research. It is possible to control the simulated aircraft with the use of an external control system. The solution proposed enables testing the aircraft control algorithms, indirect control laws (e.g. control laws modifying handling qualities), as well as testing and assessment of the students’ pilotage skills. Moreover, the solution makes it possible to conduct tests connected with aircraft control, crew management, crew cooperation and flight safety. The simulator allows us to test dangerous situations, which – because of safety reasons – is impossible during in-flight testing. This paper presents modifications to the simulator’s hardware and additional software, which enable the described research.

Stalling transport aircraft

2013 ◽  
Vol 117 (1198) ◽  
pp. 1183-1206 ◽  
Author(s):  
P. J. Bolds-Moorehead ◽  
V. G. Chaney ◽  
T. Lutz ◽  
S. Vaux
Keyword(s):  
Wind Tunnel ◽  
Flight Control ◽  
Flight Test ◽  
High Angle ◽  
Flight Testing ◽  
Control Laws ◽  
Transport Aircraft ◽  
Wind Tunnel Data ◽  
Predictive Validation ◽  
Flight Deck

Abstract Airbus and Boeing are cooperatively presenting this topic dealing with transport aircraft stalls. The paper will begin by defining a stall, followed by a review of requirements, predictive validation and flight testing. There are various ways of designing modern jet transports for the stall regime such as aerodynamic approaches, flight deck indications, and augmentation control laws to deal with the high angle-of-attack (α) arena. The goal of augmented control laws for high α is common – no full aerodynamic stall or loss of climb performance should occur in the operational flight envelope, in Normal flight control modes. The validation techniques employed in preparation for a flight test campaign will follow. These include flight characteristic predictions based on wind-tunnel data as well as pilot-in-the-loop simulation rehearsals. The preparation for flight testing will be reviewed from both the engineer and pilot viewpoints. This will be followed by a review of various flight testing that has been conducted. The paper will close with a brief foray into what the future of transport stalls could be – perhaps protection features in degraded flight control modes? What are the benefits as well as drawbacks to increased augmentation for high α?

Design and Flight Testing of Intelligent Flight Control Laws for the WVU YF-22 Model Aircraft

2005 ◽  
Author(s):  
Mario Perhinschi ◽  
Marcello Napolitano ◽  
Giampiero Campa ◽  
Brad Seanor ◽  
Srikanth Gururajan ◽  
...  
Keyword(s):  
Flight Control ◽  
Flight Testing ◽  
Control Laws ◽  
Model Aircraft

String Instabilities in Formation Flight: Limitations Due to Integral Constraints

2004 ◽  
Vol 126 (4) ◽  
pp. 873-879 ◽  
Author(s):  
P. Seiler ◽  
A. Pant ◽  
J. K. Hedrick
Keyword(s):  
Flight Control ◽  
Formation Control ◽  
Energy Savings ◽  
Feedback Loops ◽  
Formation Flight ◽  
Control Laws ◽  
Aerodynamic Efficiency ◽  
Preceding Vehicle ◽  
Specific Control ◽  
Theoretical Results

Flying in formation improves aerodynamic efficiency and, consequently, leads to an energy savings. One strategy for formation control is to follow the preceding vehicle. Many researchers have shown through simulation results and analysis of specific control laws that this strategy leads to amplification of disturbances as they propagate through the formation. This effect is known as string instability. In this paper, we show that string instability is due to a fundamental constraint on coupled feedback loops. The tradeoffs imposed by this constraint imply that predecessor following is an inherently poor strategy for formation flight control. Finally, we present two examples that demonstrate the theoretical results.

Automatic Flight Control of Unmanned Helicopter Based on Nonlinear Model

2012 ◽  
Vol 472-475 ◽  
pp. 1492-1499
Author(s):  
Run Xia Guo
Keyword(s):  
Nonlinear Model ◽  
Flight Control ◽  
Attitude Control ◽  
Lyapunov Stability Theory ◽  
Test Results ◽  
Unmanned Helicopter ◽  
Control Laws ◽  
Control Approach ◽  
State Dependent ◽  
Compensation Technique

The Unmanned helicopter (UMH) movement was divided into two parts, namely, attitude and trajectory motion. And then a two-timescale nonlinear model was established. The paper improved and expanded state dependent riccati equation (SDRE) control approach, deriving analytical conditions for achieving global asymptotic stability with lyapunov stability theory. Proof was given. By combining improved SDRE control with nonlinear feed-forward compensation technique, the full envelop flight attitude control laws could be designed. On the basis of attitude control, trajectory controller was developed. Actual flight tests were carried out. Test results show that the control strategy is highly effective.

scholarly journals Enhanced Disturbance-Observer-Based Control for a Class of Time-Delay System with Uncertain Sinusoidal Disturbances

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Xinyu Wen
Keyword(s):  
Time Delay ◽  
Flight Control ◽  
Disturbance Observer ◽  
Delay System ◽  
Delay Systems ◽  
Flight Control System ◽  
Control Laws ◽  
Nonlinear Disturbance Observer ◽  
Dynamic Performances ◽  
Uncertain Disturbance

This paper is concerned with disturbance-observer-based control (DOBC) for a class of time-delay systems with uncertain sinusoidal disturbances. The disturbances are decomposed as precise and uncertain parts using nonlinear disturbance observer (DO) after appropriate coordinate transformation. And then the two parts can be compensated by corresponding controller, respectively, such that the classic DOBC method is extended to uncertain disturbance rejection. One novel feature of the proposed method is that even if the precise disturbance parameters are inaccessible, the merits of DOBC can be inherited. By integrating the disturbance observers with feedback control laws with time delay, the disturbances can be rejected and the desired dynamic performances can be guaranteed. Finally, simulations for a flight control system are given to demonstrate the effectiveness of the results.

Divergence Speed Prediction for Practical Slung Load Shapes

2015 ◽  
Author(s):  
Brandon Liberi ◽  
Chau Ton ◽  
Narayanan Komerath
Keyword(s):  
Control System ◽  
Robust Control ◽  
Wind Tunnel ◽  
Flight Control ◽  
Flight Control System ◽  
Wind Tunnel Experiments ◽  
Flight Testing ◽  
Flight Vehicles ◽  
Analytical Functions ◽  
Speed Prediction

Given the innumerable combinations of flight vehicles, loads and flight conditions, alternatives are sought to flight testing, to certify the safe flight speed with slung loads. With well-resolved airload maps now feasible for arbitrary shapes as analytical functions, dynamic simulation predicts divergence speeds, regardless of the symmetry of the object. Likely modes of amplification are found using wind tunnel experiments with free-swinging objects. A robust control formulation enables safe flight close to divergence speed where the flight control system can prevent disturbance amplification.

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