ARMA-AKF Model of MEMS Gyro Rotation Data Random Drift Compensation

2013 ◽  
Vol 321-324 ◽  
pp. 549-552 ◽  
Author(s):  
Wei Peng Su ◽  
Yong Sheng Hao ◽  
Qi Chang Li
Keyword(s):  
Angular Rate ◽  
External Disturbance ◽  
Arma Model ◽  
Zero Point ◽  
Attitude Measurement ◽  
Adaptive Kalman Filter ◽  
Actual System ◽  
Random Drift ◽  
Drift Compensation

Application of MEMS angular rate gyro attitude when monitoring for long-term, zero-point drift and random error in cumulative points after long-term monitoring errors can significantly increase the measurement error. Using ARMA model of MEMS gyros random drift modeling and error compensation method using Adaptive Kalman Filter, which increases gyro attitude measurement of long-term reliability Last experiment. The method in accordance with the principle of time series analysis, integration of observations and estimates of actual system so that it can reflect the influence of external disturbance and noise on the system. It can also reflect the influence of system disturbance on actual system performance improves estimation precision.

Research of Random Drift for MEMS Gyroscope Based on Gray System and ARMA Model

2012 ◽  
Vol 546-547 ◽  
pp. 1526-1531
Author(s):  
Zhao Hua Liu ◽  
Jia Bin Chen ◽  
Yu Liang Mao ◽  
Chun Lei Song
Keyword(s):  
Spectral Density ◽  
Measurement System ◽  
Arma Model ◽  
Attitude Measurement ◽  
Weak Signal ◽  
Random Drift ◽  
Mems Gyroscope ◽  
Gray System ◽  
Power Spectral ◽  
The One

Due to the precision of MEMS gyroscope is currently low level, even in low precision dynamic attitude measurement system, its error is also need to be estimated and compensated. Random drift is the one of the most important factor affects MEMS Gyro’s precision. At the same time, it is a non-stationary, weak non-linear and time-variant random signal. For improving precision of gyro and reducing effects of random drift, this paper used gray GM(1, 1) model to extract established tendency signal, and used power spectral density (PSD) to identify and extract the hidden periodic weak signal, then used ARMA method to model gyro’s random drift. As the example of LCG50 MEMS gyro, the simulation experimental results show that using this method can reduce the random drift and enhance precision of gyro.

Long-term wavelength drift compensation of tunable pulsed dye laser for sodium detection lidar

2015 ◽  
Vol 354 ◽  
pp. 52-58 ◽  
Author(s):  
Yuan Xia ◽  
Xuewu Cheng ◽  
Faquan Li ◽  
Jihong Wang ◽  
Yong Yang ◽  
...  
Keyword(s):  
Dye Laser ◽  
Pulsed Dye Laser ◽  
Drift Compensation

scholarly journals The relationship between net GHG emissions and radiative forcing with an application to Article 4.1 of the Paris Agreement.

2021 ◽  
Author(s):  
Tom M. L. Wigley
Keyword(s):  
Global Warming ◽  
Radiative Forcing ◽  
Ghg Emissions ◽  
Zero Point ◽  
Paris Agreement ◽  
Test Case ◽  
Net Zero ◽  
Global Warming Potentials ◽  
The Relationship

Abstract This paper provides an assessment of Article 4.1 of the Paris Agreement on climate; the main goal of which is to provide guidance on how “to achieve the long-term temperature goal set out in Article 2”. Paraphrasing, Article 4.1 says that, to achieve this end, we should decrease greenhouse gas (GHG) emissions so that net anthropogenic GHG emissions fall to zero in the second half of this century. To aggregate net GHG emissions, 100-year Global Warming Potentials (GWP-100) are commonly used to convert non-CO2 emissions to equivalent CO2 emissions. As a test case using methane, temperature projections using GWP-100 scaling are shown to be seriously in error. This throws doubt on the use of GWP-100 scaling to estimate net GHG emissions. An alternative method to determine the net-zero point for GHG emissions based on radiative forcing is derived. This shows that the net-zero point needs to be reached as early as 2036, much sooner than in the Article 4.1 window. Other scientific flaws in Article 4.1 that further undermine its purpose to guide efforts to achieve the Article 2 temperature targets are discussed.

Monitoring and Calibration of Long Term Mooring System Design Assumptions Through Use of AIS and Weather Data

2021 ◽  
Author(s):  
Dag Børre Lillestøl ◽  
Odd Torbjørn Kårvand ◽  
Are Torstensen
Keyword(s):  
Low Cost ◽  
Environmental Data ◽  
Weather Data ◽  
Mooring System ◽  
System Behavior ◽  
Original Design ◽  
Actual System ◽  
Early Failures ◽  
And Performance

Abstract This paper outlines an approach on how to improve the mooring integrity of existing long term mooring systems by using existing and commercially available data. It will be demonstrated how the use of AIS and hindcast weather data can be used to increase understanding of mooring systems and to monitor and quantify gaps between "as-designed", "as-installed" and "as-is" of a long term mooring system. Long term moored units have traditionally suffered from many early failures, caused by damages and errors introduced in the installation phase, and costly and unnecessary "late in life" failures. A fact rated high on the agenda of the underwriters. Numerous papers have been written on this topic, but it is only in recent years the industry have started to ensure that systems are inspected to a sufficient degree with respect to the physical condition, taking these learnings into account. However, the second important element, the calibration of the mooring analysis vs. actual vessel and mooring system behavior/performance, have not yet gotten the attention required. Deviations from the intended design are introduced in the installation phase of a mooring system. In addition, the design assumptions will never be fully accurate. The gap between the design assumptions and the actual system will increase over time, and the industry today do not focus on mapping and quantifying the effect of this gap sufficiently. The described method explains how one can introduce a pro-active approach, without installing onboard equipment, but rather utilizing algorithms on existing data and design documentation. This paper focuses on the use of AIS data in combination with historic weather/environmental data and seek to demonstrate how this low-cost method can provide useful information with respect to the mooring system. To emphasize the mapped importance of such calibrations, the July 2021 Edition of the in-service DNV Class Rules, DNVGL-OS-0300, formally introduces requirements to calibration of design assumptions of long term mooring units through use of survey data, service history and actual mooring system behavior in order to ensure a unit's mooring system condition and performance is known in light of the original design assumptions.

Disturbance Estimation, Compensation, and Dynamic Shaping: New Approach and an Application to Output Stabilization of Multiple Cooperative Control

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Sang-Chul Lee ◽  
Kyungmin Jeong ◽  
Hyo-Sung Ahn
Keyword(s):  
Cooperative Control ◽  
Design Method ◽  
External Disturbance ◽  
Experimental Tests ◽  
Consensus Algorithm ◽  
Actual System ◽  
Multiple Systems ◽  
Disturbance Estimation ◽  
Output Stabilization ◽  
Estimation Scheme

This paper introduces a new disturbance estimation scheme, and a possible application to relative output stabilization of multiple systems. Using the proposed disturbance estimation scheme, total unknown external disturbance applied to a plant is estimated and compensated. Moreover, the model difference between an actual system and a desired system is also estimated and compensated. For the purpose of general use of the disturbance estimation scheme as an unknown input observer (UIO), a parameterized design method is given, even for the unstable and nonminimum phase systems. For the relative output stabilization of multiple systems, second-order consensus algorithm is additionally used. A case study, simulations, and experimental tests sequentially validate the proposed estimation and control methods.

Adaptive Sliding Mode Control of MEMS Vibrational Gyroscope

2006 ◽  
Author(s):  
J. Fei ◽  
C. Batur
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Angular Rate ◽  
External Disturbance ◽  
Adaptive Sliding Mode Control ◽  
Angular Velocity Vector ◽  
Adaptive Sliding Mode ◽  
Mode Control ◽  
Control Scheme ◽  
On Line

This paper presents a new sliding mode adaptive controller for MEMS z-axis gyroscope. The proposed adaptive sliding mode control algorithm can on-line estimate the component of the angular velocity vector, which is orthogonal to the plane of oscillation of the gyroscope (the z-axis) and the linear damping and stiffness model coefficients. The stability of the closed-loop system can be guaranteed with the proposed control strategy. The numerical simulation for MEMS Gyroscope is investigated to verify the effectiveness of the proposed adaptive sliding mode control scheme. It is shown that the proposed adaptive sliding mode control scheme offers several advantages such as on-line estimation of gyroscope parameters including angular rate and large robustness to parameter variations and external disturbance.

Long-term in vitro transformation of 2-line ferrihydrite to goethite/hematite at 4, 10, 15 and 25°C

Clay Minerals ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 433-438 ◽  
Author(s):  
U. Schwertmann ◽  
H. Stanjek ◽  
H.-H. Becher
Keyword(s):  
Zero Point ◽  
Transformation Rate ◽  
Ambient Temperatures ◽  
Ph Values ◽  
In Vitro Transformation ◽  
Zero Point Of Charge ◽  
Ph Range ◽  
Increasing Temperature

Abstract2-line ferrihydrite stored in water at ambient temperatures from 4 to 25°C and at ten different pH values between 2.5 and 12 for up to 10–12 y transformed to both goethite and hematite at all temperatures and pH values except at pH 12 where only goethite was formed. The rate and degree of transformation (20–100%) increased with increasing pH and temperature. The hematite/ (hematite+goethite) ratio varied between 0 and ~0.8, increased with increasing temperature and showed a strong maximum at pH 7–8 which increased from 0.1–0.2 at 4°C to 0.7–0.8 at 25°C. The maximum coincides with the zero point of charge of ferrihydrite where its solubility and, thus, its via-solution transformation rate to goethite are minimal. We assume, therefore, that in this pH-range the (slower) via-solution transformation to hematite can more efficiently compete with that to goethite.

Towards Automated Nanoassembly With the Atomic Force Microscope: A Versatile Drift Compensation Procedure

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Florian Krohs ◽  
Cagdas Onal ◽  
Metin Sitti ◽  
Sergej Fatikow
Keyword(s):  
Atomic Force Microscope ◽  
Estimation Method ◽  
Thermal Drift ◽  
Promising Technique ◽  
Drift Estimation ◽  
Atomic Force ◽  
Drift Compensation ◽  
Monte Carlo Localization ◽  
Afm Probe

While the atomic force microscope (AFM) was mainly developed to image the topography of a sample, it has been discovered as a powerful tool also for nanomanipulation applications within the last decade. A variety of different manipulation types exists, ranging from dip-pen and mechanical lithography to assembly of nano-objects such as carbon nanotubes (CNTs), deoxyribonucleic acid (DNA) strains, or nanospheres. The latter, the assembly of nano-objects, is a very promising technique for prototyping nanoelectronical devices that are composed of DNA-based nanowires, CNTs, etc. But, pushing nano-objects in the order of a few nanometers nowadays remains a very challenging, labor-intensive task that requires frequent human intervention. To increase throughput of AFM-based nanomanipulation, automation can be considered as a long-term goal. However, automation is impeded by spatial uncertainties existing in every AFM system. This article focuses on thermal drift, which is a crucial error source for automating AFM-based nanoassembly, since it implies a varying, spatial displacement between AFM probe and sample. A novel, versatile drift estimation method based on Monte Carlo localization is presented and experimental results obtained on different AFM systems illustrate that the developed algorithm is able to estimate thermal drift inside an AFM reliably even with highly unstructured samples and inside inhomogeneous environments.

scholarly journals Robust Controller for a Vision Feedback Based Telepointer

2016 ◽  
Vol 6 (6) ◽  
pp. 2870
Author(s):  
Shah Newaz Mohammad Abdul Kader ◽  
Mohd. Marzuki Mustafa ◽  
Aini Hussain
Keyword(s):  
External Disturbance ◽  
Fast Response ◽  
Computer Supported Cooperative Work ◽  
Proportional Integral Derivative ◽  
Laser Pointer ◽  
Actual System ◽  
Robust Controller ◽  
Proportional Integral Derivative Controller ◽  
Speed Of Response ◽  
Vision Feedback

<p><span>Telepointer is a very useful tool for teleconsultation and teleproctoring, whereby a telepointer via teleconferencing is a perfect example of computer-supported cooperative work (CSCW) and digital telepresence. To this end, many telepointers are introduced for digital telepresence. However, there are still concerns regarding the speed of response and robustness of the system. It is rather difficult to model the actual system in order to design the controller. This paper described the development of a telepointer and its controller for a real time communication using vision feedback. The main focus of this study was to control the Laser Pointer (LP) with a discrete time PID (proportional–integral–derivative) controller which was tuned using Ziegler-Nichols (ZN) method. The results indicated that the tuned controller bring about fast response with no overshoot and steady state errors at the output response. The controller was shown to be robust against changes in sampling time and external disturbance.</span></p>

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