Results 81 to 90 of about 143,454 (291)

Spacecraft flight control system design selection process for a geostationary communication satellite [PDF]

The Earth's first artificial satellite, Sputnik 1, slowly tumbled in orbit. The first U.S. satellite, Explorer 1, also tumbled out of control. Now, as we launch the Mars observer and the Cassini spacecraft, stability and control have become higher ...
Barret, C.
core   +1 more source

Fully 3D‐Printed Wave‐Wound Electromagnetic Motors

Advanced Materials Technologies, EarlyView.
This work presents the first fully 3D‐printed wave‐wound electromagnetic motors, which are created using conductive nanoparticle inks, carbon‐filled nylon polymers, and surface mount components. These motors can achieve a stall torque of 7.62N·mmA−1$7.62 \nobreakspace N{\cdot }mm A^{-1}$ and efficiency of 28.2 %, which approaches the performance of ...
Joseph Schwalbe, Sebastian Mettes, Eduardo Francke, Kenneth W. Allen, Yi Chen Mazumdar   +4 more
wiley   +1 more source

Determining the effective elastic thickness through cross-correlation between isostatic disturbances

Geodesy and Geodynamics
The elastic thickness parameter was estimated using the mobile correlation technique between the observed isostatic disturbance and the gravity disturbance calculated through direct gravimetric modeling.
Nelson Ribeiro-Filho, Cristiano Mendel Martins, Raissa Moraes Baldez, Ivaldevingles Rodrigues de Souza Júnior, Franck Eitel Kemgang Ghomsi   +4 more
doaj   +1 more source

Dynamic model and control of a new quadrotor unmanned aerial vehicle with tilt-wing mechanism [PDF]

, 2008
In this work a dynamic model of a new quadrotor aerial vehicle that is equipped with a tilt-wing mechanism is presented. The vehicle has the capabilities of vertical take-off/landing (VTOL) like a helicopter and flying horizontal like an airplane ...
Aksit, Mahmut Faruk, Akşit, Mahmut Faruk, Cetinsoy, Ertugrul, Gulez, Kayhan, Gülez, Kayhan, Kandemir, İlyas, Kandemir, Ilyas, Oner, Kaan Taha, Unel, Mustafa, Çetinsoy, Ertuğrul, Öner, Kaan Taha, Ünel, Mustafa   +11 more
core  

Multiobjective Codesign Optimization of a Planar Pneumatic Artificial Muscle‐Based Snake‐Like Robot for Enhanced Agility and Energy Efficiency

Advanced Robotics Research, EarlyView.
A codesign multiobjective optimization framework was developed to enhance the morphology and controller of a snake‐like robot driven by artificial muscles. It improved planar locomotion, agility, and power efficiency. The approach optimized link geometry and controller gains, revealing that shorter muscles near joints and longer linkages maximize ...
Ayla Valles, Mahdi Haghshenas‐Jaryani
wiley   +1 more source

Rigorous geoid-from-quasigeoid correction using gravity disturbances

Journal of Geodetic Science, 2015
Abstract We present rigorous solutions for the geoid-fromquasigeoid correction (GQC) using Taylor expansions of surface gravity disturbances along the vertical from the Earth’s surface to the geoid. One solution takes advantage of the topographic potential bias at the geoid, which can be expressed by a simple formula.
openaire   +2 more sources

Stable Imitation of Multigait and Bipedal Motions for Quadrupedal Robots Over Uneven Terrains

Advanced Robotics Research, EarlyView.
How are quadrupedal robots empowered to execute complex navigation tasks, including multigait and bipedal motions? Challenges in stability and real‐world adaptation persist, especially with uneven terrains and disturbances. This article presents an imitation learning framework that enhances adaptability and robustness by incorporating long short‐term ...
Erdong Xiao, Yinzhao Dong, Ji Ma, Peng Lu   +3 more
wiley   +1 more source

Detection of Earth’s Free Oscillations Utilizing TianQin

Space: Science & Technology
The measurement of Earth’s free oscillations plays an important role in studying Earth’s large-scale structure. Space technology development presents a potential method to observe these normal modes by measuring intersatellite distances.
Yuxin Yang, Kun Liu, Xuefeng Zhang, Yiming Hu   +3 more
doaj   +1 more source

Scale Factor Calibration for a Rotating Accelerometer Gravity Gradiometer

Sensors, 2018
Rotating Accelerometer Gravity Gradiometers (RAGGs) play a significant role in applications such as resource exploration and gravity aided navigation. Scale factor calibration is an essential procedure for RAGG instruments before being used.
Zhongguang Deng, Chenyuan Hu, Xiangqing Huang, Wenjie Wu, Fangjing Hu, Huafeng Liu, Liangcheng Tu   +6 more
doaj   +1 more source

Gravitational Shielding Effects in Gauge Theory of Gravity

, 2003
In 1992, E.E.Podkletnov and R.Nieminen find that, under certain conditions, ceramic superconductor with composite structure has revealed weak shielding properties against gravitational force. In classical Newton's theory of gravity and even in Einstein's
Wu, Ning
core   +1 more source