Results 21 to 30 of about 64,260 (282)

Robust Flat Filtering Control of a Two Degrees of Freedom Helicopter Subject to Tail Rotor Disturbances

International Journal of Applied Mathematics and Computer Science, 2023
This article deals with modelling and a flatness-based robust trajectory tracking scheme for a two degrees of freedom helicopter, which is subject to four types of tail rotor disturbances to validate the control scheme robustness. A mathematical model of
Sánchez-Meza Victor-Gabriel, Lozano-Hernández Yair, Gutiérrez-Frías Octavio, Lozada-Castillo Norma, Luviano-Juárez Alberto   +4 more
doaj   +1 more source

Imaging and Motion Parameter Estimation of Flying Helicopter With Duo Airborne SARs in $X$-Band

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2022
Duo airborne synthetic aperture radars in the $X$-band are proposed to acquire images of a flying helicopter. The backscattered signals manifest entangled features attributed to the compound linear motion of fuselage and spin motion of rotors.
Chou-Wei Kiang, Jean-Fu Kiang
doaj   +1 more source

Experimental research of single - rotor helicopter unintentional yaw rotation

Научный вестник МГТУ ГА, 2020
Aviation accidents related to unintentional rotation may periodically occur while flying single-rotor helicopters. On-time and correct actions may help the pilot to find the way out of this hazardous situation.
V. V. Efimov, V. A. Ivchin, O. E. Chernigin, K. O. Chernigin   +3 more
doaj   +1 more source

Design and Determination of Aerodynamic Coefficients of a Tail-Sitter Aircraft by Means of CFD Numerical Simulation

Machines, 2022
Vertical take-off and landing (VTOL) aircraft have become important aerial vehicles for various sectors, such as security, health, and commercial sectors.
Emmanuel Alejandro Islas-Narvaez, Jean Fulbert Ituna-Yudonago, Luis Enrique Ramos-Velasco, Mario Alejandro Vega-Navarrete, Octavio Garcia-Salazar   +4 more
doaj   +1 more source

The influence of helicopter tail rotor parameters on RCS

Hangkong gongcheng jinzhan
High requirements have been placed on the stealth performance of armed helicopters during wartime missions，in order to reduce the probability of the helicopter being found during the task，based on geometric optics method and consistent diffraction theory，
ZHAO Qijun
doaj   +1 more source

A method for tail rotor aerodynamic force prediction under rotor interference based on coupled momentum source and blade element theory

Xibei Gongye Daxue Xuebao
Due to the influence of slip flow and wake, the tail rotor of a helicopter may produce strong unsteady aerodynamic force in its main rotor interference flow field, which may affect the helicopter control and lead to structural failure.
WEN Long, ZHAO Xu, WANG Weite, LIU Xinyuan, YU Haiyang, HE Long, HE Shun   +6 more
doaj   +1 more source

A New Algorithm on Automatic Trimming for Helicopter Rotor Aerodynamic Loads

Aerospace, 2023
In order to simulate the flight state of the helicopter effectively, it is necessary to trim the helicopter during the forward flight in a wind tunnel test.
Xinfan Yin, Hongxu Ma, Xianmin Peng, Guichuan Zhang, Honglei An, Liangquan Wang   +5 more
doaj   +1 more source

RNA‐Micelles as Self‐Assembling Structures for Efficient Co‐Delivery of Synergistic siRNA and Nucleoside Analogues to Treat CRC Lung Metastasis

Advanced Functional Materials, EarlyView.
Two kinds of self‐assembled RNA micelles were used to co‐deliver synergistic siRNA and nucleoside analogues for the treatment of colorectal cancer lung metastases. Near‐complete elimination of lung cancer metastases was confirmed in an orthotopic lung metastasis model constructed using human colorectal cancer lung metastases patient surgical samples to
Kai Jin, Piotr Rychahou, Daniel W. Binzel, B. Mark Evers, Peixuan Guo   +4 more
wiley   +1 more source

Research of the crosswind effect on the single-rotor helicopter unintentional yaw rotation

Научный вестник МГТУ ГА
During the operation of single-rotor helicopters, aviation accidents quite frequently occur in the form of an unintentional turn or even a yaw rotation, causing, as a rule, a ground collision.
V. V. Efimov, V. A. Ivchin, K. O. Chernigin   +2 more
doaj   +1 more source

Targeting the ARRDC3–DRP1 Axis via hUMSC‐Derived Exosomal CRYAB for Neuroprotection in Cerebral Ischemia/Reperfusion Injury

Advanced Healthcare Materials, EarlyView.
Intranasally administered hUMSC‐derived exosomes modulate the CRYAB–ARRDC3–Drp1 axis, alleviating mitochondrial dysfunction and ferroptosis, enhancing neuronal survival, reducing oxidative stress, and promoting functional recovery in ischemia‐reperfusion injury, offering a promising therapeutic strategy for ischemic stroke.
Rong ji, Zengyu Zhang, Zhuohang Liu, Kaicheng Yang, Xueyu Mao, Min Chu, Yong Wang, Jing Zhao   +7 more
wiley   +1 more source