Study on the Key Technology of the Coastal Waterway Long-Distance Tide Extract and its Software Realization

2014 ◽  
Vol 568-570 ◽  
pp. 1463-1468
Author(s):  
Sheng Ping Wang ◽  
Yan Feng Li ◽  
Xiao Yu Li ◽  
Hai Bo Qin

In this paper, we developed a tide extraction software system which is based on GPS RTK / PPK and MRU (Motion Reference Unit) . Firstly, we analysis the quality control and the attitude correction which are the most important key technologies in this software . At the same time, the frame of the whole system, the computer environment, the software development tool are also analysised in detial in this paper. Finally, the stability and accuracy of this software system are verified by the experiment in Guangdong Yamen coastal waterway .

2014 ◽  
Vol 687-691 ◽  
pp. 1038-1043
Author(s):  
Yong Tao Yu ◽  
Ming Chen ◽  
Feng Tian ◽  
Ying Ji Shan

Current OTS (Online Test System, OTS) of airborne electrical equipments in the environments of mechanics is only able to test statically but dynamically. To solve the problem, a new kind of dynamic test system based on PXI bus is designed. In the design, modular instrument resources that used in the third generation of ATE (Auto Test System, ATE) commonly is adopted to prove the system’s reusability, extensibility and standard ability, digital signal acquisition is replaced with analog signal acquisition to realize dynamic test, support from the method of process monitoring is drew to get the capability to detect the reversible failure in UUT (Unit Under Test, UTT), VC++ language is used as the software development tool to control the system and record test data. In the special mechanics environment such as centrifuge, drawing lessons from the experience of the new concept dynamic test, the system architecture of remote control acquisition is used to prove the stability and efficiency of the test system greatly. The experimental result shows that the system runs well and has more advantages such as high efficiency of auto-test and reliability of failure diagnosis results, meeting new demand of the airborne electrical equipments’ online test in the environments of mechanics.


2015 ◽  
Vol 738-739 ◽  
pp. 1349-1352
Author(s):  
Ting Ai ◽  
Hao Kang ◽  
Yue Ou Ren

Virtual reality (VR) technology is a new and comprehensive application of information technology. It can make people get the same feeling such as in the real world. VR has become one of the three major means of human exploration of the objective world rule. As one of the key technologies of building digital multi-dimensional information space technology support platform, virtual reality technology in the development and application domain expands unceasingly. This paper designs and realizes a 3D virtual campus roaming system based-VRML and mainly studies the key technology of overall modeling and local modeling, then achieves virtual campus interactive roaming function Using VRML development tool. The paper provides some experience for virtual reality technology in simulation campus construction in the areas of application.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2830
Author(s):  
Sili Wang ◽  
Mark P. Panning ◽  
Steven D. Vance ◽  
Wenzhan Song

Locating underground microseismic events is important for monitoring subsurface activity and understanding the planetary subsurface evolution. Due to bandwidth limitations, especially in applications involving planetarily-distributed sensor networks, networks should be designed to perform the localization algorithm in-situ, so that only the source location information needs to be sent out, not the raw data. In this paper, we propose a decentralized Gaussian beam time-reverse imaging (GB-TRI) algorithm that can be incorporated to the distributed sensors to detect and locate underground microseismic events with reduced usage of computational resources and communication bandwidth of the network. After the in-situ distributed computation, the final real-time location result is generated and delivered. We used a real-time simulation platform to test the performance of the system. We also evaluated the stability and accuracy of our proposed GB-TRI localization algorithm using extensive experiments and tests.


Author(s):  
Weitao Chen ◽  
Shenhai Ran ◽  
Canhui Wu ◽  
Bengt Jacobson

AbstractCo-simulation is widely used in the industry for the simulation of multidomain systems. Because the coupling variables cannot be communicated continuously, the co-simulation results can be unstable and inaccurate, especially when an explicit parallel approach is applied. To address this issue, new coupling methods to improve the stability and accuracy have been developed in recent years. However, the assessment of their performance is sometimes not straightforward or is even impossible owing to the case-dependent effect. The selection of the coupling method and its tuning cannot be performed before running the co-simulation, especially with a time-varying system.In this work, the co-simulation system is analyzed in the frequency domain as a sampled-data interconnection. Then a new coupling method based on the H-infinity synthesis is developed. The method intends to reconstruct the coupling variable by adding a compensator and smoother at the interface and to minimize the error from the sample-hold process. A convergence analysis in the frequency domain shows that the coupling error can be reduced in a wide frequency range, which implies good robustness. The new method is verified using two co-simulation cases. The first case is a dual mass–spring–damper system with random parameters and the second case is a co-simulation of a multibody dynamic (MBD) vehicle model and an electric power-assisted steering (EPAS) system model. Experimental results show that the method can improve the stability and accuracy, which enables a larger communication step to speed up the explicit parallel co-simulation.


2021 ◽  
Vol 11 (5) ◽  
pp. 2098
Author(s):  
Heyi Wei ◽  
Wenhua Jiang ◽  
Xuejun Liu ◽  
Bo Huang

Knowledge of the sunshine requirements of landscape plants is important information for the adaptive selection and configuration of plants for urban greening, and is also a basic attribute of plant databases. In the existing studies, the light compensation point (LCP) and light saturation point (LSP) have been commonly used to indicate the shade tolerance for a specific plant; however, these values are difficult to adopt in practice because the landscape architect does not always know what range of solar radiation is the best for maintaining plant health, i.e., normal growth and reproduction. In this paper, to bridge the gap, we present a novel digital framework to predict the sunshine requirements of landscape plants. First, the research introduces the proposed framework, which is composed of a black-box model, solar radiation simulation, and a health standard system for plants. Then, the data fitting between solar radiation and plant growth response is used to obtain the value of solar radiation at different health levels. Finally, we adopt the LI-6400XT Portable Photosynthetic System (Li-Cor Inc., Lincoln, NE, USA) to verify the stability and accuracy of the digital framework through 15 landscape plant species of a residential area in the city of Wuhan, China, and also compared and analyzed the results of other researchers on the same plant species. The results show that the digital framework can robustly obtain the values of the healthy, sub-healthy, and unhealthy levels for the 15 landscape plant species. The purpose of this study is to provide an efficient forecasting tool for large-scale surveys of plant sunshine requirements. The proposed framework will be beneficial for the adaptive selection and configuration of urban plants and will facilitate the construction of landscape plant databases in future studies.


Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 333
Author(s):  
Jian Le ◽  
Hao Zhang ◽  
Cao Wang ◽  
Xingrui Li ◽  
Jiangfeng Zhu

To enhance the stability and accuracy of the digital-physical hybrid simulation system of a modular multilevel converter-based high voltage direct current (MMC-HVDC) system, this paper presents an improved power interface modeling algorithm based on ideal transformer method (ITM). By analyzing the stability condition of a hybrid simulation system based on the ITM model, the current of a so-called virtual resistance is added to the control signal of the controlled current source in the digital subsystem, and the stability of the hybrid simulation system with the improved power interface model is analyzed. The value of the virtual resistance is optimized by comprehensively considering system stability and simulation precision. A two-terminal bipolar MMC-HVDC simulation system based on the proposed power interface model is established. The comparisons of the simulation results verify that the proposed method can effectively improve the stability of the hybrid simulation system, and at the same time has the advantages of high simulation accuracy and easy implementation.


2017 ◽  
Vol 21 (3) ◽  
pp. 782-807 ◽  
Author(s):  
Yanli Wang ◽  
Shudao Zhang

AbstractWe present a numerical method to solve the Vlasov-Poisson-Fokker-Planck (VPFP) system using the NRxx method proposed in [4, 7, 9]. A globally hyperbolic moment system similar to that in [23] is derived. In this system, the Fokker-Planck (FP) operator term is reduced into the linear combination of the moment coefficients, which can be solved analytically under proper truncation. The non-splitting method, which can keep mass conservation and the balance law of the total momentum, is used to solve the whole system. A numerical problem for the VPFP system with an analytic solution is presented to indicate the spectral convergence with the moment number and the linear convergence with the grid size. Two more numerical experiments are tested to demonstrate the stability and accuracy of the NRxx method when applied to the VPFP system.


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