scholarly journals Effect of the Simultaneous Variation in Blade Root Chord Length and Blade Taper on Helicopter Flight Control Effort

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Tugrul Oktay ◽  
Firat Sal

In this study, the effect of simultaneous variation in blade root chord length and blade taper on the control effort of helicopter flight control system (i.e., FCS) of a helicopter is investigated. Therefore, helicopter models (i.e., complex, control-oriented, and physics-based models) including the main physics and essential dynamics are used. The effect of simultaneous variation in the blade root chord length and blade taper (i.e., in both chordwise and lengthwise directions dependently) on the control effort of an FCS of a helicopter and also on the closed-loop responses is studied. Comparisons in terms of the control effort and peak values with and without variations in the blade root chord and blade taper changes are carried out. For helicopter FCS variance-constrained controllers, specific output variance-constrained controllers are beneficial.

2019 ◽  
Vol 92 (2) ◽  
pp. 172-179
Author(s):  
Firat Sal

Purpose The purpose of this study is to examine the effect of passive and active morphing of blade root chord length and blade taper on the control effort of the flight control system (FCS) of a helicopter. Design/methodology/approach Physics-based helicopter models, which are functions of passive and active morphing, are created and applied in helicopter FCS design to determine the control effort. Findings Helicopters, having both passively and actively morphing blade root chord length and blade taper, experience less control effort than the ones having either only passively morphing blade root chord length or only blade taper or only actively morphing blade root chord length and blade taper. Practical implications Both passively and actively morphing blade root chord length and blade taper can be implemented for more economical autonomous helicopter flights. Originality/value Main novelty of our article is simultaneous application of passive and active morphing ideas on helicopter root chord length and blade taper. It is also proved in this study that using both passive and active morphing ideas on helicopter blade root chord and blade taper causes much less energy consumption than using either only passive morphing idea on helicopter blade root chord and blade taper or only active morphing idea on helicopter blade root chord and blade taper. This also reduces fuel consumption and also makes environment cleaner.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Tugrul Oktay ◽  
Firat Sal

Helicopter moving horizontal tail (i.e., MHT) strategy is applied in order to save helicopter flight control system (i.e., FCS) energy. For this intention complex, physics-based, control-oriented nonlinear helicopter models are used. Equations of MHT are integrated into these models and they are together linearized around straight level flight condition. A specific variance constrained control strategy, namely, output variance constrained Control (i.e., OVC) is utilized for helicopter FCS. Control energy savings due to this MHT idea with respect to a conventional helicopter are calculated. Parameters of helicopter FCS and dimensions of MHT are simultaneously optimized using a stochastic optimization method, namely, simultaneous perturbation stochastic approximation (i.e., SPSA). In order to observe improvement in behaviors of classical controls closed loop analyses are done.


2019 ◽  
Vol 92 (2) ◽  
pp. 264-270
Author(s):  
Firat Sal

Purpose The purpose of this paper presents the effects of actively morphing root chord and taper on the energy of the flight control system (i.e. FCS). Design/methodology/approach Via regarding previously mentioned purposes, sophisticated and realistic helicopter models are benefitted to examine the energy of the FCS. Findings Helicopters having actively morphing blade root chord length and blade taper consume less control energy than the ones having one of or any of passively morphing blade root chord length and blade taper. Practical implications Actively morphing blade root chord length and blade taper can be used for cheaper helicopter operations. Originality/value The main originality of this paper is applying active morphing strategy on helicopter blade root chord and blade taper. In this paper, it is also found that using active morphing strategy on helicopter blade root chord and blade taper reasons less energy consumption than using either passively morphing blade root chord length plus blade taper or not any. This causes also less fuel consumption and green environment.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Jinshuo Hu ◽  
Hongbin Gu

A literature review of flight control technology is presented for large-scale helicopter. Challenges of large-scale helicopter flight control system (FCS) design are illustrated. Following this, various flight control methodologies are described with respect to their engineering implementation and theoretical developments, whose advantages and disadvantages are also analyzed. Then, the challenging research issues on flight control technology are identified, and future directions are highlighted.


2012 ◽  
Vol 468-471 ◽  
pp. 529-533 ◽  
Author(s):  
Fu Yang Chen ◽  
Wen Li Luan ◽  
Rui Hou

In this paper, an adaptive control scheme is proposed for the uncertain flight control system of the helicopter with fault in vertical flight. The controller is designed using sliding mode theory and adaptive technology. In the controller, the nonlinear function is brought in, which can enlarge the small errors, and saturate the large errors. And it can make sure the good transient performances and stability of the helicopter flight control system. Finally, the simulation results of the nonlinear helicopter flight system illustrate the effectiveness and feasibility of the proposed scheme in the paper.


2000 ◽  
Vol 6 (6) ◽  
pp. 553-566 ◽  
Author(s):  
Ian Postlethwaite ◽  
Ioannis K. Konstantopoulos ◽  
Xiao-Dong Sun ◽  
Daniel J. Walker ◽  
Adrian G. Alford

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