Results 61 to 70 of about 1,986 (195)

Statistical modeling to relate technology readiness to schedule

Systems Engineering, Volume 27, Issue 1, Page 120-139, January 2024.
Abstract Projects from U.S. National Aeronautics and Space Administration and Department of Energy technology development activities provide historical data on project completion timelines versus technology readiness levels that were assessed during the life cycle of a program. A statistical analysis was performed to develop a method to forecast future
C. Robert Kenley, Shrividya Subramanian, Katherine M. Adams   +2 more
wiley   +1 more source

Path‐Tracking Control of Tilting Quadrotor UAV Based on Variable Structure Sliding Mode Control Method

International Journal of Aerospace Engineering, Volume 2024, Issue 1, 2024.
Tilting quadcopter unmanned aerial vehicles have the ability to perform vertical takeoff and landing, hover in the air, and cruise at high speeds, They can complete various flight tasks. Due to the special flight mode of tilting quadcopter unmanned aerial vehicles, in transition mode, as the tilt angle changes, the control process of the drone becomes ...
Qinghua Liu, Ke Zhang, Yunfan Pan, Huan Zhang, Jinchao Chen   +4 more
wiley   +1 more source

Autonomous aerial perching and unperching using omnidirectional tiltrotor and switching controller [PDF]

IEEE International Conference on Robotics and Automation
Aerial unperching of multirotors has received little attention as opposed to perching that has been investigated to elongate operation time. This study presents a new aerial robot capable of both perching and unperching autonomously on/from a ...
Dongjae Lee, Sunwoo Hwang, Jeonghyun Byun, Seungjae Lee, H. J. Kim   +4 more
semanticscholar   +1 more source

Modelling and Simulation in High-Fidelity Crash Analysis of NGCTR-TD Composite Wing

Aerospace
This paper presents a methodology that involves the development of high-fidelity modeling and simulation procedures aimed at supporting virtual certification for crashworthiness requirements specific to tiltrotor aircraft, addressing the critical need ...
Luigi Di Palma, Mariacristina Nardone, Claudio Pezzella, Marika Belardo   +3 more
doaj   +1 more source

Wind Tunnel Investigation of Transient Propeller Loads for Non-Axial Inflow Conditions

Aerospace
Recent developments in electrical Vertical Take-off and Landing (eVTOL) vehicles show the need for a better understanding of transient aero-mechanical propeller loads for non-axial inflow conditions.
Catharina Moreira, Nikolai Herzog, Christian Breitsamter   +2 more
doaj   +1 more source

Electric VTOL design exploration and configurations comparison for urban air mobility

Aerospace Research Communications
The development of Urban Air Mobility (UAM) has led to the introduction of various electric vertical takeoff and landing (eVTOL) aircraft configurations, which plays a crucial role in determining performance.
Xue Chen, Xuanyu Yao, Yunkun Man, Yaolong Liu, Yao Zheng   +4 more
doaj   +1 more source

An Innovative Control Allocation Framework for a Novel Tiltrotor Aircraft

IEEE Access, 2020
Control allocation is still a challenge for tiltrotor aircraft due to effectors' redundancy, dramatic nonlinearities and cross-coupling. Besides this, the external disturbance caused by the unique configuration of tiltrotor such as larger wing area and ...
Yifan Xu, Qian Zhang, Zelong Yu
doaj   +1 more source

Aerodynamic Research on the Wing Design of a 3000 kg Hexa Tiltrotor eVTOL

Engineering Proceedings
This paper describes a design method for 3000 kg hexa tiltrotor eVTOL wings. According to this design method, this paper designs and optimizes the wing area and incidence angle using CFD technology, provides the optimal wing design scheme, and estimates ...
Yafei Zheng, Wei Qiao, Xinlei Wang
doaj   +1 more source

Estimation Method for Basic Parameters of High-Speed Vertical Take-Off and Landing Aircraft

Aerospace
The research aims to propose a basic parameter estimation method for high-speed vertical take-off and landing (HSVTOL) aircraft, balancing rotor and fixed-wing mode requirements.
Yu Wang, Qihang Li, Pan Li
doaj   +1 more source

CFD Study of an Annular-Ducted Fan Lift System for VTOL Aircraft

Aerospace, 2015
The present study aimed at assessing a novel annular-ducted fan lift system for VTOL aircraft through computational fluid dynamics (CFD) simulations. The power and lift efficiency of the lift fan system in hover mode, the lift and drag in transition mode,
Yun Jiang, Bo Zhang, Tao Huang
doaj   +1 more source