scholarly journals TOA and TDTOA-based augmented state pulsar integrated navigation error suppression method

Author(s):  
晓琳 宁 ◽  
明臻 桂 ◽  
月清 黄 ◽  
建成 房 ◽  
伟仁 吴
2021 ◽  
pp. 1-12
Author(s):  
Yongwei Tang ◽  
Huijuan Hao ◽  
Jun Zhou ◽  
Yuexiang Lin ◽  
Zhenzhen Dong

AGV (Automated Guided Vehicle) technology has attracted increasing attention. Precise control of AGV position and attitude information in complex operating environment is a key part of smart factories. With outdoor AGV as a platform, this study uses BDS/INS combined navigation system combining Beidou positioning system and inertial navigation system and takes the velocity and position difference between BDS and INS as a model. An integrated navigation method is proposed to improve bee colony algorithm and optimize the BP neural network-assisted Kalman filtering to achieve accurate positioning. Moreover, the optimization of BP neural network navigation using INS navigation, network-assisted navigation and bee colony algorithm is simulated. Results demonstrate that the integrated navigation algorithm has effectiveness and feasibility, and can solve the problems of BDS misalignment and large INS navigation error in complex environments.


2017 ◽  
Author(s):  
Shibing Deng ◽  
Maruja Lira ◽  
Stephen Huang ◽  
Kai Wang ◽  
Crystal Valdez ◽  
...  

AbstractThe use of ultra-deep, next generation sequencing of circulating tumor DNA (ctDNA) holds great promise for early detection of cancer as well as a tool for monitoring disease progression and therapeutic responses. However, the low abundance of ctDNA in the bloodstream coupled with technical errors introduced during library construction and sequencing complicates mutation detection. To achieve high accuracy of variant calling via better distinguishing low frequency ctDNA mutations from background errors, we introduce TNER (Tri-Nucleotide Error Reducer), a novel background error suppression method that provides a robust estimation of background noise to reduce sequencing errors. It significantly enhances the specificity for downstream ctDNA mutation detection without sacrificing sensitivity. Results on both simulated and real healthy subjects’ data demonstrate that the proposed algorithm consistently outperforms a current, state of the art, position-specific error polishing model, particularly when the sample size of healthy subjects is small. TNER is publicly available at https://github.com/ctDNA/TNER.


2019 ◽  
Vol 304 ◽  
pp. 04008
Author(s):  
Luca Castigliola ◽  
Flavia Causa ◽  
Michele Grassi

This paper aims at presenting an integrated navigation algorithm designed for estimating the navigation state of the STRATOFLY vehicle (LAPCAT–MR3). STRATOFLY project has been funded by the European Commission, under the framework of Horizon 2020 plan, with the aim of assessing the potential of high–speed transport vehicle. The complex interaction between elements of an air-breathing hypersonic vehicle represents a new paradigm in aircraft design. In particular, one of the needs for early GNC analysis in the case of LAPCAT–MR3 vehicle is the assessment of navigation performance over the reference trajectory. The navigation algorithm presented in this paper is based on an augmented state EKF data fusion algorithm exploiting inertial measurements provided by gyroscopes and accelerometers, heading estimates provided by a magnetometer and satellite-based measurements provided by a spaceborne GNSS receiver, considering GPS, GLONASS and GALILEO constellations.


Author(s):  
Xiaojun Ju ◽  
Jili Lu ◽  
Hongyan Jin

Based on the structure analysis and the working principle of cylindrical giant magnetostricve actuator (CGMA) for ball screw preload, a thermal error suppression method using oil cooling system to control the temperature is proposed. Firstly, the heat transfer model and thermal circuit model of CGMA are established; next, the steady-state temperature model and the thermal expansion displacement model of cylindrical giant magnetostrictive material (CGMM) are obtained according to the heat-transfer rules and loop analysis method in circuit analysis; finally, the design parameters of the oil-cooling temperature control system are determined by combining thermal circuit model analysis with finite element simulation analysis. Such optimization method saves a lot of computation and provides a simple way for the design of oil cooling structure. In addition, a test platform for the CGMA is established. The experimental results indicate that the measured temperatures are in good agreement with the simulation results under forced oil cooling, and the relative error is less than 5%, which proves the rationality of the temperature control system. Moreover, the output accuracy and stability of the CGMA is significantly improved with proposed oil cooling method, which further confirms the thermal error suppression method is effective. As a result, this study provides a basis for the application of CGMA in the precise adjustment of double-nut ball screw preload.


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