scholarly journals The New Evolution for SIA Rotorcraft UAV Project

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Juntong Qi ◽  
Dalei Song ◽  
Lei Dai ◽  
Jianda Han ◽  
Yuechao Wang
Keyword(s):  
Control Method ◽  
Test Bed ◽  
Advanced Control ◽  
Autonomous Mode ◽  
Chinese Academy Of Sciences ◽  
Aerial Vehicle ◽  
Active Modeling ◽  
Rotorcraft Uav ◽  
The One ◽  
Academy Of Sciences

This paper describes recent research on the design, implement, and testing of a new small-scaled rotorcraft Unmanned Aerial Vehicle (RUAV) system—ServoHeli-40. A turbine-powered UAV weighted less than 15 kg was designed, and its major components were tested at the Shenyang Institute of Automation, Chinese Academy of Sciences in Shenyang, China. The aircraft was designed to reach a top speed of more than 20 mps, flying a distance of more than 10 kilometers, and it is going to be used as a test-bed for experimentally evaluating advanced control methodologies dedicated on improving the maneuverability, reliability, as well as autonomy of RUAV. Sensors and controller are all onboard. The full system has been tested successfully in the autonomous mode using the multichannel active modeling controller. The results show that in a real windy environment the rotorcraft UAV can follow the trajectory which was assigned by the ground control station exactly, and the new control method is obviously more effective than the one in the past year's research.

Construction of Alkylated Stereocenters

2017 ◽  
Author(s):  
Zara M. Seibel ◽  
Tristan H. Lambert
Keyword(s):  
Cross Coupling ◽  
Israel Institute ◽  
University Of Utah ◽  
Chinese Academy Of Sciences ◽  
Palladium Catalyzed ◽  
Institute Of Technology ◽  
Quaternary Stereocenters ◽  
The One ◽  
The University ◽  
Academy Of Sciences

Hirohisa Ohmiya and Masaya Sawamura at Hokkaido University reported (Angew. Chem. Int. Ed. 2013, 52, 5350) the copper-catalyzed, γ-selective allylation of terminal alkyne 1 to produce the chiral skipped enyne 3 with high ee. A method to synthe­size asymmetric skipped diene 6 via copper-catalyzed allylic allylation of diene 4 was developed (Chem. Commun. 2013, 49, 3309) by Ben L. Feringa at the University of Groningen. Prof. Feringa also disclosed (J. Am. Chem. Soc. 2013, 135, 2140) the regi­oselective and enantioselective allyl–allyl coupling of bromide 7 with allyl Grignard under Cu catalysis in the presence of phosphoramidite 8. James P. Morken of Boston College reported (Org. Lett. 2013, 15, 1432) the cross-coupling of allylboronate 11 with a mixture of alkenes 10a,b under palladium catalysis to produce diene 13 with high ee. Jian Liao at the Chengdu Institute of Biology Chinese Academy of Sciences and the University of Chinese Academy of Sciences reported (Angew. Chem. Int. Ed. 2013, 52, 4207) the palladium-catalyzed allylic alkylation of indole using the chi­ral bis(sulfoxide) phosphine ligand 15. Yi-Xia Jia at the Zhejiang University of Technology reported (J. Am. Chem. Soc. 2013, 135, 2983) the enantioselective alkyl­ation of indole to produce the trifluoromethyl adduct 19 using nickel catalysis in the presence of bisoxazoline ligand 18. Sarah E. Reisman at the California Institute of Technology disclosed (J. Am. Chem. Soc. 2013, 135, 7442) the reductive cross-coupling of acid chloride 20 and benzyl chloride 21 using a nickel complex with bisoxazoline ligand 22 and manganese(0) as reductant. Ilan Marek at the Technion-Israel Institute of Technology reported (Angew. Chem. Int. Ed. 2013, 52, 5333) a method for the construction of all-carbon quaternary stereocenters, such as the one present in aldehyde 25, using a diastereoselective car­bometallation of cyclopropene 24 followed by oxidation and ring opening. Switching from methyl Grignard and copper iodide to MeCuCNLi reverses the diastereoselec­tivity of the carbometallation and allows access to the opposite enantiomer. Matthew S. Sigman at the University of Utah reported (J. Am. Chem. Soc. 2013, 135, 6830) the redox–relay oxidative Heck arylation of alkenyl alcohol 27 with boronic acid 26 using a palladium catalyst and pyridine oxazole ligand 28 to produce the γ-substituted aldehyde 29.

scholarly journals The Design of Terahertz Monolithic Integrated Frequency Multipliers Based on Gallium Arsenide Material

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 336
Author(s):  
Jin Meng ◽  
Luwei Qi ◽  
Xiaoyu Liu ◽  
Jingtao Zhou ◽  
Dehai Zhang ◽  
...  
Keyword(s):  
Gallium Arsenide ◽  
Circuit Design ◽  
Design Method ◽  
Schottky Diodes ◽  
Frequency Multiplier ◽  
Frequency Multipliers ◽  
Chinese Academy Of Sciences ◽  
The One ◽  
Academy Of Sciences ◽  
Independent Design

A global design method for a terahertz monolithic integrated frequency multiplier is proposed. Compared with a traditional independent design, the method in this paper adopts overall optimization and combines the device with the circuit design. The advantage is that it provides a customized design for frequency multipliers according to specifications. On the basis of the gallium arsenide process of the Institute of Microelectronics, Chinese Academy of Sciences, two types of Schottky diodes have been developed to meet the needs of different designs. On the one hand, a Schottky diode with a 3 μm junction’s diameter was used in the design of the 200 GHz balanced doubler and, on the other hand, a diode with a 5 μm diameter was used in the 215 GHz unbalanced tripler. The measured results indicated that the output power of the doubler was more than 250 μW at 180~218 GHz, and the maximum was 950 μW at 198 GHz when driven with 12.3 mW, whereas that of the tripler was above 5 mW at 210~218 GHz and the maximum exceeded 10 mW. Such frequency multiplier sources could be widely used in terahertz imaging, radiometers, and so on.

Analysis and Evaluation of One-Way Time Service by Beidou Dual-Frequency Multichannel Receiver

2013 ◽  
Vol 718-720 ◽  
pp. 1234-1239
Author(s):  
Fan Yang ◽  
Hai Bo Yuan ◽  
Shao Wu Dong
Keyword(s):  
Dual Frequency ◽  
Time Service ◽  
Analysis And Evaluation ◽  
Chinese Academy Of Sciences ◽  
Geo Satellites ◽  
Precision Time ◽  
The One ◽  
Technology And Economy ◽  
Academy Of Sciences ◽  
Service Theory

High precision time plays a key role in technology and economy domain. as the time transmitting carrier, time service restricts timing precision of users. Combined with the characteristics of Beidou navigation system, the paper describes the one-way time service theory, accomplishes Beidou one-way timing algorithm and the software design. Finally, using the satellite data of Beidou dual-frequency multichannel receiver at the National Time Service Center (NTSC), the Chinese Academy of Sciences, the precision of Beidou one-way time service by the different types of satellites-GEO satellites, IGSO satellites, GEO combined with IGSO satellites-is analyzed and evaluated. The experiment result will provide important reference for optimizing the function of Beidou one-way time service.

scholarly journals Test bed for applications of heterogeneous unmanned vehicles

2017 ◽  
Vol 14 (1) ◽  
pp. 172988141668711 ◽  
Author(s):  
Filiberto Muñoz Palacios ◽  
Eduardo Steed Espinoza Quesada ◽  
Guillaume Sanahuja ◽  
Sergio Salazar ◽  
Octavio Garcia Salazar ◽  
...  
Keyword(s):  
Software Development ◽  
Unmanned Vehicles ◽  
Ground Vehicles ◽  
Test Bed ◽  
Consensus Algorithms ◽  
Vehicle Systems ◽  
Aerial Vehicle ◽  
Software Development Kit ◽  
The One ◽  
Simon Fraser University

This article addresses the development and implementation of a test bed for applications of heterogeneous unmanned vehicle systems. The test bed consists of unmanned aerial vehicles (Parrot AR.Drones versions 1 or 2, Parrot SA, Paris, France, and Bebop Drones 1.0 and 2.0, Parrot SA, Paris, France), ground vehicles (WowWee Rovio, WowWee Group Limited, Hong Kong, China), and the motion capture systems VICON and OptiTrack. Such test bed allows the user to choose between two different options of development environments, to perform aerial and ground vehicles applications. On the one hand, it is possible to select an environment based on the VICON system and LabVIEW (National Instruments) or robotics operating system platforms, which make use the Parrot AR.Drone software development kit or the Bebop_autonomy Driver to communicate with the unmanned vehicles. On the other hand, it is possible to employ a platform that uses the OptiTrack system and that allows users to develop their own applications, replacing AR.Drone’s original firmware with original code. We have developed four experimental setups to illustrate the use of the Parrot software development kit, the Bebop Driver (AutonomyLab, Simon Fraser University, British Columbia, Canada), and the original firmware replacement for performing a strategy that involves both ground and aerial vehicle tracking. Finally, in order to illustrate the effectiveness of the developed test bed for the implementation of advanced controllers, we present experimental results of the implementation of three consensus algorithms: static, adaptive, and neural network, in order to accomplish that a team of multiagents systems move together to track a target.

scholarly journals An improved coupling model for water flow, sediment transport and bed evolution (CASFE v.1)

2014 ◽  
Vol 7 (2) ◽  
pp. 2429-2454
Author(s):  
S. He ◽  
W. Liu ◽  
X. Li ◽  
C. Ouyang
Keyword(s):  
Sediment Transport ◽  
Water Flow ◽  
Morphological Evolution ◽  
Coupling Model ◽  
Chinese Academy Of Sciences ◽  
Bed Evolution ◽  
The One ◽  
Volume Method ◽  
Academy Of Sciences ◽  
Sediment Mixtures

Abstract. This paper presents a new coupling model to simulate water flow, sediment transport and bed evolution based on the shallow water assumption, depth-average integration as well as the morphological evolution (Chinese Academy of Sciences flow-erosion model, CASFE). The model takes account of the effects of rainfall, entrainment and deposition on the motion of water–sediment mixtures. Limitations and drawbacks of other authors' models are pointed out according to the comparison among these models. The finite volume method has been adopted to solve the one-dimensional dam-break problem considering an erodible bed. Numerical results indicate that the model can adequately describe the complex dynamic problems. Simulation results demonstrate that the entrainment and deposition significantly affects the flow dynamics and morphological evolution.

scholarly journals Preface to the Interfacial Science Developments at the Chinese Academy of Sciences Virtual Special Issue

Langmuir ◽  
2020 ◽  
Vol 36 (41) ◽  
pp. 12087-12087 ◽  
Author(s):  
Yilin Wang ◽  
Shaoyi Jiang ◽  
Zhan Chen ◽  
Shu-Hong Yu ◽  
Gilbert Walker
Keyword(s):  
Special Issue ◽  
Interfacial Science ◽  
Chinese Academy Of Sciences ◽  
Academy Of Sciences

scholarly journals Emulation of grid-forming inverters using real-time PC and 4-quadrant voltage amplifier

2021 ◽  
Author(s):  
Wolf Schulze ◽  
Maurizio Zajadatz ◽  
Michael Suriyah ◽  
Thomas Leibfried
Keyword(s):  
Real Time ◽  
Control Method ◽  
Current Control ◽  
Control Methods ◽  
Test Bed ◽  
Test Scenario ◽  
Power Semiconductors ◽  
Voltage Amplifier ◽  
Grid Side ◽  
Virtual Synchronous Machine

AbstractA test bed for the evaluation of novel control methods of inverters for renewable power generation is presented. The behavior of grid-following and grid-forming control in a test scenario is studied and compared.Using a real-time capable control platform with a cycle time of 50 µs, control methods developed with Matlab/Simulink can be implemented. For simplicity, a three-phase 4‑quadrant voltage amplifier is used instead of an inverter. Thus, the use of modulation and switched power semiconductors can be avoided. In order to show a realistic behavior of a grid-side filter, passive components can be automatically connected as L‑, LC- or LCL-filter. The test bed has a nominal active power of 43.6 kW and a nominal voltage of 400 V.As state-of-the-art grid-following control method, a current control in the d/q-system is implemented in the test bed. A virtual synchronous machine, the Synchronverter, is used as grid-forming control method. In combination with a frequency-variable grid emulation, the behavior of both control methods is studied in the event of a load connection in an island grid environment.

Two new species of the spider genus Pholcus Walckenaer, 1805 (Araneae: Pholcidae) from Pakistan

Zootaxa ◽  
2020 ◽  
Vol 4820 (1) ◽  
pp. 177-185
Author(s):  
TIANQI LAN ◽  
ZHIYUAN YAO ◽  
ABID ALI ◽  
GUO ZHENG ◽  
SHUQIANG LI
Keyword(s):  
New Species ◽  
Species Group ◽  
Male And Female ◽  
Female Type ◽  
Chinese Academy Of Sciences ◽  
Two New Species ◽  
Academy Of Sciences ◽  
Gilgit Baltistan ◽  
First Time ◽  
Beijing China

The genus Pholcus Walckenaer, 1805 is reported from Pakistan for the first time. Two new species of the Pholcus nenjukovi species-group are described: Pholcus hamuchal Yao & Li sp. nov. (Gilgit Baltistan, male and female) and Pholcus kalam Yao & Li sp. nov. (Khyber Pakhtunkhwa, male and female). Type material is deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China.

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