Continuity, real-time, and accuracy are the key technical indexes of evaluating comprehensive performance of a strapdown inertial navigation system (SINS). However, Schuler, Foucault, and Earth periodic oscillation errors significantly cut down the real-time accuracy of SINS. A method for oscillation error restriction of SINS based on forecasted time series is proposed by analyzing the characteristics of periodic oscillation errors. The innovative method gains multiple sets of navigation solutions with different phase delays in virtue of the forecasted time series acquired through the measurement data of the inertial measurement unit (IMU). With the help of curve-fitting based on least square method, the forecasted time series is obtained while distinguishing and removing small angular motion interference in the process of initial alignment. Finally, the periodic oscillation errors are restricted on account of the principle of eliminating the periodic oscillation signal with a half-wave delay by mean value. Simulation and test results show that the method has good performance in restricting the Schuler, Foucault, and Earth oscillation errors of SINS.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541942 | PMC |
http://dx.doi.org/10.3390/s150717433 | DOI Listing |
Micromachines (Basel)
December 2024
Research Laboratory "Sensor Systems Based on Integrated Photonics Devices", Ufa University of Science and Technology, 32, Z. Validi St., Ufa 450076, Russia.
Radio photonic technologies have emerged as a promising solution for addressing microwave frequency synthesis challenges in current and future communication and sensing systems. One particularly effective approach is the optoelectronic oscillator (OEO), a simple and cost-effective electro-optical system. The OEO can generate microwave signals with low phase noise and high oscillation frequencies, often outperforming traditional electrical methods.
View Article and Find Full Text PDFLang Cogn Neurosci
July 2024
Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, USA.
The engagement of predictive mechanisms during language comprehension can facilitate processing and modulate neural oscillatory activity. These modulations include alpha-band activity decreases prior to expected words, reflecting anticipatory preparation, and frontal theta-band activity following unexpected words, reflecting engagement of cognitive control. It remains unknown how these oscillatory dynamics are impacted by aging.
View Article and Find Full Text PDFeNeuro
January 2025
Research School of Psychology, Australian National University, 0200, Australia.
Inner speech refers to the silent production of language in one's mind. As a purely mental action without obvious physical manifestations, inner speech has been notoriously difficult to quantify. Inner speech is thought to be closely related to overt speech.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Machine Learning Group, Technische Universität Berlin, 10587 Berlin, Charlottenburg, Germany.
We introduce the alchemical harmonic approximation (AHA) of the absolute electronic energy for charge-neutral iso-electronic diatomics at fixed interatomic distance d0. To account for variations in distance, we combine AHA with this ansatz for the electronic binding potential, E(d)=(Eu-Es)Ec-EsEu-Esd/d0+Es, where Eu, Ec, Es correspond to the energies of the united atom, calibration at d0, and the sum of infinitely separated atoms, respectively. Our model covers the two-dimensional electronic potential energy surface spanned by distances of 0.
View Article and Find Full Text PDFBMC Res Notes
January 2025
Department of Mathematics, Jimma University, Jimma, Ethiopia.
Objective: In this work, singularly perturbed time dependent delay parabolic convection-diffusion problem with Dirichlet boundary conditions is considered. The solution of this problem exhibits boundary layer at the right of special domain. In this layer the solution experiences steep gradients or oscillation so that traditional numerical methods may fail to provide smooth solutions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!