Preliminary parameters design for a long endurance unmanned helicopter with low rotor-disc loading

2020 ◽  
pp. 095441002097389
Author(s):  
Hong Zhao ◽  
Jian-Bo Li ◽  
Yuan Wang ◽  
Zhi-Gang Wang
Keyword(s):  
Flight Control ◽  
Evaluation Model ◽  
Load Ratio ◽  
Collaborative Optimization ◽  
Flight Performance ◽  
Unmanned Helicopter ◽  
Handling Qualities ◽  
Flying Qualities ◽  
Long Endurance ◽  
Quality Evaluation Model

This paper investigates the design of a long-endurance unmanned helicopter (LEUH) with low rotor disc loading (LRDL) and low rotor speed (LRS). Due to the flaws in flying qualities caused by the LRDL and the LRS, this paper establishes a flying quality evaluation model in which handling qualities (FQs) and flight control (FC) are introduced into the distributed multi-objective collaborative optimization (DMOCO) of the helicopters. The comprehensive design optimization on preliminary parameters of the LEUH in wind shear is also carried out. Numerical simulation results show that the LRDL and the LRS technologies are successfully applied to LEUH, with the FQs and the flight performance considered. Compared with A160 LEUH, the payload load ratio is significantly improved.

Development of a control law to improve the handling qualities for short-range air-to-air combat maneuvers

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402093679
Author(s):  
Chong-Sup Kim ◽  
Chang-Ho Ji ◽  
Byoung Soo Kim
Keyword(s):  
Flight Control ◽  
Short Range ◽  
Control Method ◽  
Control Law ◽  
Fighter Aircraft ◽  
Handling Qualities ◽  
Flying Qualities ◽  
Air Combat ◽  
Handling Quality ◽  
The Mathematical Model

Modern fighter aircraft have been designed to have high maneuverability in order to preoccupy strategic superiority in short-range air-to-air combat between fighter aircraft in warfare. Digital fly-by-wire flight control system design is aimed at providing good handling qualities for all mission task elements over the entire flight envelope. To provide both excellent gross acquisition and fine tracking compatibility, simultaneously for air-to-air combat maneuvers, this article presents a common longitudinal control law design of a task-dependent self-adjusting command-path pilot prefilter gain scheduler within the same control law design architecture and response type based on nonlinear dynamic inversion control. We perform the frequency- and time-domain analyses based on the mathematical model of T-50 advanced trainer aircraft to evaluate the basic flying qualities of the proposed control method. Furthermore, the pilot evaluation is performed to evaluate the gross acquisition and fine tracking capability for air-to-air tracking maneuvers in a handling quality simulator. The evaluation results reveal that the proposed control method improves the fine tracking capability without the degradation of gross acquisition.

Design and flight test of active flutter suppression on the X-56A multi-utility technology test-bed aircraft

2016 ◽  
Vol 120 (1228) ◽  
pp. 893-909 ◽  
Author(s):  
E. L. Burnett ◽  
J. A. Beranek ◽  
B. T. Holm-Hansen ◽  
C. J. Atkinson ◽  
P. M. Flick
Keyword(s):  
Flight Control ◽  
Flight Test ◽  
Test Bed ◽  
Control Laws ◽  
Control Approach ◽  
Mode Control ◽  
Flying Qualities ◽  
Technical Challenges ◽  
Long Endurance ◽  
Aircraft Configurations

ABSTRACTEfforts to develop the next generation of aircraft with ever-increasing levels of performance – higher, farther, faster, cheaper – face great technical challenges. One of these technical challenges is to reduce structural weight of the aircraft. Another is to look to aircraft configurations that have been unrealizable to date. Both of these paths can lead to a rigid flex coupling phenomenon that can result in anything from poor flying qualities to the loss of an aircraft due to flutter. This has led to a need to develop an integrated flight and aeroelastic control capability where structural dynamics are included in the synthesis of flight control laws. Studies have indicated that the application of an integrated flight and aeroelastic control approach to a SensorCraft high-altitude long-endurance vehicle would provide substantial performance improvement(1,2). Better flying qualities and an expanded flight envelope through multi-flutter mode control are two areas of improvement afforded by integrated flight and aeroelastic control. By itself, multi-flutter mode control transforms the flutter barrier from a point of catastrophic structural failure to a benign region of flight. This paper discusses the history and issues associated with the development of such an integrated flight and aeroelastic control system for the X-56A aircraft.

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.

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