Fixed-time Observer Based Safety Control for a Quadrotor UAV

Author(s):  
Sicheng Zhou ◽  
Kexin Guo ◽  
Xiang Yu ◽  
Lei Guo ◽  
Lihua Xie
Author(s):  
Kexin Guo ◽  
Wenyu Zhang ◽  
Yukai Zhu ◽  
Jindou Jia ◽  
Xiang Yu ◽  
...  

2019 ◽  
Vol 13 (18) ◽  
pp. 3117-3123
Author(s):  
Jiannan Chen ◽  
Changchun Hua ◽  
Xinping Guan

2020 ◽  
Vol 10 (17) ◽  
pp. 5986
Author(s):  
Rong Chen ◽  
Yuzhu Bai ◽  
Yong Zhao ◽  
Zhijun Chen ◽  
Tao Sheng

This paper studies the safety control problem for rotating spacecraft proximity maneuver in presence of complex shaped obstacles. First, considering the attitude change of the target spacecraft, a dynamic model of close-range relative motion in a body-fixed coordinate system is derived using a novel approach. Then, the Gaussian mixture model (GMM) is utilized to reconstruct the complex shape of the spacecraft, and a novel GMM-based artificial potential function (APF) is proposed to represent the collision avoidance requirement. By combining GMM-based APF with fixed-time stability methodology, a fixed-time control (FTC) is designed for close-range proximity operation to a rotating spacecraft having a complex shape. The presented GMM-FTC scheme can guarantee the convergence of relative state errors, and ensure that no collision occurs. Finally, simulation results are provided to illustrate the feasibility of the proposed control approach.


Author(s):  
M. Sato ◽  
Y. Ogawa ◽  
M. Sasaki ◽  
T. Matsuo

A virgin female of the noctuid moth, a kind of noctuidae that eats cucumis, etc. performs calling at a fixed time of each day, depending on the length of a day. The photoreceptors that induce this calling are located around the neurosecretory cells (NSC) in the central portion of the protocerebrum. Besides, it is considered that the female’s biological clock is located also in the cerebral lobe. In order to elucidate the calling and the function of the biological clock, it is necessary to clarify the basic structure of the brain. The observation results of 12 or 30 day-old noctuid moths showed that their brains are basically composed of an outer and an inner portion-neural lamella (about 2.5 μm) of collagen fibril and perineurium cells. Furthermore, nerve cells surround the cerebral lobes, in which NSCs, mushroom bodies, and central nerve cells, etc. are observed. The NSCs are large-sized (20 to 30 μm dia.) cells, which are located in the pons intercerebralis of the head section and at the rear of the mushroom body (two each on the right and left). Furthermore, the cells were classified into two types: one having many free ribosoms 15 to 20 nm in dia. and the other having granules 150 to 350 nm in dia. (Fig. 1).


2013 ◽  
Author(s):  
Yuenghsiang E. Huang ◽  
Peter Y. Chen ◽  
Autumn D. Krauss ◽  
Apryl Rogers

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