Flight control of a Rotary wing UAV using adaptive backstepping

Author(s):  
Bilal Ahmed ◽  
Hemanshu R. Pota
2021 ◽  
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli ◽  
Giuseppe Vitrani

Abstract Stability Control Augmentation Systems (SCAS) are widely adopted to enhance the flight stability of rotary-wing aircraft operating in difficult aerodynamic conditions, such as low altitude missions, stationary flight nearby vertical walls or in presence of heavy gusts. Such systems are based upon small electro-hydraulic servosystems controlled in position through a dedicated servovalve. The SCAS operates with limited authority over the main control linkage translating the pilot input in the movement of the main flight control actuator. Being critical for the operability of the helicopter, the definition of a Prognostics and Health Management (PHM) framework for the SCAS systems would provide significant advantages, such as better risk mitigation, improved availability, and a reduction in the occurrences of unpredicted failures which still represent one of the most known downsides of helicopters. This paper provides the results of a preliminary analysis on the effects of the inception and progression of several degradation types within a simulated SCAS system. Signals usually available within such devices are hence combined with measurements provided by additional sensors to check the feasibility of a PHM system with and without dedicated sensors. The resulting features selection process shows that although the dedicated measurements are required to design a complete PHM system, it appears nonetheless possible to obtain valuable information on the health status of the SCAS system without resorting to additional sensors.


Author(s):  
Dennis B. Beringer ◽  
Robert E. Joslin

Excessive pilot flight-control forces have been identified as a causal factor in aircraft accidents, incidents, and anomalous events. However, the regulatory design requirements for fixed-wing and rotary-wing air-craft that are contained in the Code of Federal Regulations (CFR) have not been validated or updated in decades, and data for some specific situations were never included in the specifications. Results are presented for a recent study of over 300 participants categorized by gender, pilot/nonpilot status, and age group (10-year brackets from 18 through 69). Controls examined included sticks (left, center, right), yoke, rudder pedals (left, right), and helicopter collective. Results indicated that, on average, more than half of the sample could not achieve the short-term tabled forces used as reference points. However, more than half (60 to 87%) were able to sustain the prescribed long-term forces for 4 minutes or more in some control axes. It is recommended that reference tables both internal to the CFR and referenced by the CFR be modified to accommodate a larger percentage of the current user population.


2007 ◽  
Vol 30 (2) ◽  
pp. 322-336 ◽  
Author(s):  
L. Sonneveldt ◽  
Q. P. Chu ◽  
J. A. Mulder

2013 ◽  
Vol 46 (10) ◽  
pp. 1-8
Author(s):  
Xilin Yang ◽  
Luis Mejias Alvarez ◽  
Matt Garratt ◽  
Hemanshu Pota

Drones ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 24
Author(s):  
Javaan Chahl ◽  
Nasim Chitsaz ◽  
Blake McIvor ◽  
Titilayo Ogunwa ◽  
Jia-Ming Kok ◽  
...  

Many drone platforms have matured to become nearly optimal flying machines with only modest improvements in efficiency possible. “Chimera” craft combine fixed wing and rotary wing characteristics while being substantially less efficient than both. The increasing presence of chimeras suggests that their mix of vertical takeoff, hover, and more efficient cruise is invaluable to many end users. We discuss the opportunity for flapping wing drones inspired by large insects to perform these mixed missions. Dragonflies particularly are capable of efficiency in all modes of flight. We will explore the fundamental principles of dragonfly flight to allow for a comparison between proposed flapping wing technological solutions and a flapping wing organism. We chart one approach to achieving the next step in drone technology through systems theory and an appreciation of how biomimetics can be applied. New findings in dynamics of flapping, practical actuation technology, wing design, and flight control are presented and connected. We show that a theoretical understanding of flight systems and an appreciation of the detail of biological implementations may be key to achieving an outcome that matches the performance of natural systems. We assert that an optimal flapping wing drone, capable of efficiency in all modes of flight with high performance upon demand, might look somewhat like an abstract dragonfly.


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