scholarly journals Latitude Determination and Error Analysis for Stationary SINS in Unknow-Position Condition

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2558
Author(s):  
Suier Wang ◽  
Gongliu Yang ◽  
Wei Chen ◽  
Lifen Wang
Keyword(s):  
Navigation System ◽  
Estimation Method ◽  
Experimental Tests ◽  
The Self ◽  
Measurement Unit ◽  
Test Results ◽  
Bias Estimation ◽  
Short Time ◽  
The Relationship

The initial geographic latitude information is the key to the self-alignment of the strapdown inertial navigation system (SINS), but how to determine the latitude when the latitude cannot be obtained directly or in a short time? The latitude determination (LD) methods are introduced, including magnitude method, geometric method, and analytical methods 1 and 2, to solve this situation only by the output of the SINS itself. Simulation and experimental test results validate the efficiency of these LD methods. In order to improve the accuracy of the LD, the error of the LD method is derived through comparative analysis. Based on the relationship between LD error and inertial measurement unit (IMU) bias. Partial bias estimation method is introduced and executed during latitude determination. After compensating the estimated IMU bias, the accuracy of the LD will be further improved. Latitude errors are also affected by the latitude where SINS is located. Comprehensive simulation and experimental tests verify the effectiveness of the method. The IMU determined latitude can not only be used to achieve the self-alignment of the SINS, but also to correct the navigation latitude of the long-term SINS, thereby improving the autonomy and positioning accuracy of the navigation system.

scholarly journals A Novel Monitoring Navigation Method for Cold Atom Interference Gyroscope

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 222 ◽  
Author(s):  
Lin Zhang ◽  
Wei Gao ◽  
Qian Li ◽  
Runbing Li ◽  
Zhanwei Yao ◽  
...  
Keyword(s):  
Navigation System ◽  
Inertial Measurement Unit ◽  
Cold Atom ◽  
Measurement Unit ◽  
Simulation Test ◽  
Filtering Technique ◽  
High Dynamic ◽  
Novel Design ◽  
Navigation Method

The implementation principle of a typical three-pulse cold atom interference gyroscope is introduced in this paper. Based on its configuration and current research status, the problems of cold atom interference gyro are pointed out. The data-rate is insufficient, and it is difficult to achieve high dynamic measurement. Then, based on these two limitations, a novel design of the monitoring navigation system of the cold atom interference gyroscope (CAIG) and an intermediate-grade inertial measurement unit (IMU) was proposed to obtain the long-term position result without GPS signals, such as the Inertial Navigation System (INS) in underwater vehicles. While the CAIG was used as the external gyro, the bias of IMU and the misalignment angle between the CAIG-frame and the IMU-frame are obtained through filtering technique. The simulation test and field test demonstrated the improvements of the long-term positioning accuracy of the INS.

A Quaternion-Based Sliding Mode Observer for Gyro-Bias Estimation and Attitude Reconstruction

2019 ◽  
Author(s):  
Yuan Tian ◽  
Marc Compere ◽  
Sergey Drakunov
Keyword(s):  
Sliding Mode ◽  
Estimation Method ◽  
The Body ◽  
Sliding Mode Observer ◽  
Measurement Unit ◽  
Bias Estimation ◽  
Simple Formulation ◽  
The Real ◽  
Observer Error ◽  
Gyro Bias

Abstract Localization accuracy is one of the most important parts of Unmanned Vehicle Systems, Automated Vehicles, Robotics and Navigation. The 6-DOF Inertial Measurement Unit (IMU) is a commonly used device for inertial navigation and is composed of a 3-axis accelerometer and 3-axis gyroscope. The body-fixed IMU measurements are combined with initial values to produce a position and orientation estimate in the inertial frame with every new measurement. However, IMU performance is greatly degraded by bias, scale-factor, non-orthogonality, temperature, and noise. This paper develops a sliding mode observer specifically focused on gyroscope bias estimation to improve gyro measurement results. The work presented here improves the performance of tilt sensors equipped in a commercially available smartphones with accelerometers and gyroscopes. The algorithm uses quaternions to avoid the well-known Euler angle singularities also known as gimbal lock. The observed gyro-bias can be used to reconstruct an improved estimation of the real attitude. A sliding-mode observer was constructed, and A* Matrix stability criterion were used to guarantee observer error convergence in finite time. The algorithm was verified using both a simulated IMU model and experimental tests with a custom designed rotational platform. Simulation tests used a predefined gyros-bias to ensure the algorithm-estimated results converged to the correct value. Simulation results show the observer error quickly converges to zero and the gyro-bias estimation converged to the expected values. The results also show that the proposed method is very effective for reconstructing the real attitude using the observed gyro-bias. This study presents a fast, simple gyro-bias estimation method that can help reconstruct the real attitude with a simple formulation that eliminates complicated constraints.

scholarly journals Power and Persuasion: Processes by Which Perceived Power Can Influence Evaluative Judgments

2017 ◽  
Vol 21 (3) ◽  
pp. 223-241 ◽  
Author(s):  
Pablo Briñol ◽  
Richard E. Petty ◽  
Geoffrey R. O. Durso ◽  
Derek D. Rucker
Keyword(s):  
The Self ◽  
Present Review ◽  
Psychological Processes ◽  
Short Term ◽  
Evaluative Judgments ◽  
Long Term Consequences ◽  
The Relationship ◽  
Structured Approach ◽  
Perceived Power

The present review focuses on how power—as a perception regarding the self, the source of the message, or the message itself—affects persuasion. Contemporary findings suggest that perceived power can increase or decrease persuasion depending on the circumstances and thus might result in both short-term and long-term consequences for behavior. Given that perceptions of power can produce different, and even opposite, effects on persuasion, it might seem that any relationship is possible and thus prediction is elusive or impossible. In contrast, the present review provides a unified perspective to understand and organize the psychological literature on the relationship between perceived power and persuasion. To accomplish this objective, present review identifies distinct mechanisms by which perceptions of power can influence persuasion and discusses when these mechanisms are likely to operate. In doing so, this article provides a structured approach for studying power and persuasion via antecedents, consequences, underlying psychological processes, and moderators. Finally, the article also discusses how power can affect evaluative judgments more broadly.

A Design of MIMU/GPS Integrated Navigation System

2013 ◽  
Vol 278-280 ◽  
pp. 1719-1722 ◽  
Author(s):  
Xiao Yu Zhang ◽  
Chun Lei Song
Keyword(s):  
Navigation System ◽  
Inertial Measurement Unit ◽  
High Performance ◽  
Inertial Navigation System ◽  
Measurement Unit ◽  
Integrated Navigation ◽  
Test Results ◽  
Simulation Test ◽  
Integrated Navigation System ◽  
Navigation Algorithm

A new scheme of small integrated navigation system based on micro inertial measurement unit (MIMU), global position system (GPS) is presented. The characteristic of these sensors and the structure of system are introduced respectively. The TI high performance floating point DSP TMS320C6713B is used as core processor, which is designed to realize both the data collecting and the navigation calculating. According to the error models of inertial navigation system, an integrated navigation algorithm used Kalman filter is proposed to fuse the information from all of the sensors. The simulation test results show the feasibility of the system design.

scholarly journals Static and Fatigue Failures of Adhesively Bonded Laminate Joints in Moist Environments

2011 ◽  
Vol 20 (8) ◽  
pp. 1217-1242 ◽  
Author(s):  
K. B. Katnam ◽  
A. D. Crocombe ◽  
H. Sugiman ◽  
H. Khoramishad ◽  
I. A. Ashcroft
Keyword(s):  
Cohesive Zone ◽  
Experimental Tests ◽  
Static Fatigue ◽  
Test Results ◽  
Adhesively Bonded ◽  
Aerospace Applications ◽  
Numerical Predictions ◽  
Fatigue Failures ◽  
Good Agreement

Advanced structural adhesives are now an important joining technique in automobile and aerospace applications. The perceived uncertainty in the long-term structural performance of bonded members when subjected to static/fatigue loads in aggressive environments is probably restricting an even more widespread use of this joining technology. In this article, the effect of moisture on the static and fatigue resistances of adhesively bonded laminate joints was investigated. Experimental tests were performed on both aged and unaged adhesively bonded laminate joints for static and fatigue responses. Further, using a cohesive zone approach for the adhesive bondlines, a combined diffusion–stress analysis was developed to predict the progressive damage observed in the joints tested experimentally. The numerical predictions were found to be in good agreement with the experimental test results.

Research on the Relationship between Clay Content in Aggregate and Water Stability of Rubber Asphalt Mixture

2013 ◽  
Vol 639-640 ◽  
pp. 346-349
Author(s):  
Zhao Bin Xie
Keyword(s):  
Significant Influence ◽  
Asphalt Mixture ◽  
Clay Content ◽  
Water Stability ◽  
Test Results ◽  
Road Engineering ◽  
Stability Performance ◽  
Speed Up ◽  
The Relationship

In order to verify the characterization degree of water stability, research selects some clay content aggregate retrieved from road engineering field to produce rubber asphalt mixture and carry out the water stability test. Test results show that clay content in aggregate has a significant influence on the water stability of rubber asphalt mixture. When the content of clay in aggregate less than 1%, the influence on water stability is smaller; when the clay content exceeds 2%, the decay rate on water stability performance and long term properties obviously speed up, resulted in serious water damage.

scholarly journals The Impact of Oil Prices on the Economy of Vietnam

2015 ◽  
Vol 22 (04) ◽  
pp. 142-159
Author(s):  
Hoa Nguyen Thi Lien ◽  
Trang Tran Thu ◽  
Giang Nguyen Le Ngan
Keyword(s):  
Industrial Production ◽  
Oil Prices ◽  
Test Results ◽  
Macroeconomic Performance ◽  
Price Shocks ◽  
Short Term ◽  
Correction Model ◽  
The Impact ◽  
The Relationship

In this paper we study the relationship between oil prices and macroeconomic performance by investigating the impact of oil price shocks on key macroeconomic variables of Vietnam over the 2001–2012 period. In order to test the relationship between oil prices and the value of industrial production, we use cointegration method to consider the long-term relationship and Error Correction Model (ECM) to ponder the short-term one. The test results show that the price of oil and the value of industrial production in Vietnam are positively correlated in the long term, whereas in the short term the volatility of oil prices in the last two months will negatively affect the fluctuation in the value of the current industrial production.

scholarly journals THE RELATION OF ANXIETY AND KNOWLEDGE WITH LABOR READINESS IN COVID-19 PANDEMIC

2021 ◽  
Vol 5 (4) ◽  
pp. 349
Author(s):  
Ervina Puspa Wahyu Angesti ◽  
Nining Febriyana
Keyword(s):  
Pregnant Women ◽  
Sampling Technique ◽  
Anxiety Level ◽  
Test Results ◽  
Third Trimester ◽  
Cross Sectional ◽  
The Third ◽  
Cross Sectional Design ◽  
The Relationship

Background: 107,000 pregnant women in Indonesia experiencing anxiety while facing childbirth. A Research shows that anxiety is more experienced in Primigravida's pregnant women. Pregnant women anxiety can arise, especially in the third trimester until delivery. During the COVID-19 pandemic, pregnant women feel increasingly anxious because the virus spreads relatively easily. This study was aimed to analyze the relationship between the anxiety level and knowledge of pregnant women in the third trimester with readiness to face childbirth during the COVID-19 pandemic in Puskesmas Benowo and Tenggilis. Methods: This type of research was observational analytic with a cross-sectional design. The number of samples was 76 third trimester pregnant women suitable the criteria that is primigravida, physiologic pregnancy, not in a long-term medication and willing to be a respondent. The sampling technique was purposive sampling. The data was analyzed with Spearman’s Statistic test. Results: as many as 57.5% of respondents had severe anxiety with low readiness for childbirth and good knowledge of COVID-19. It was caused by the drug or vaccine for the Covid-19 that had not been found, and made pregnant women even more anxious and feared of something unwanted happening. Anxiety of pregnant women who were about to give birth greatly affected the readiness of the mother in preparing for childbirth, the more anxious pregnant women were, the less they would be prepared for laboring. The statistic analyze says that There was a relationship between the level of anxiety of third trimester pregnant women with readiness to give birth during the COVID-19 pandemic (p = 0.00), there was a relationship between the knowledge level with readiness to give birthd during the COVID-19 pandemic p = 0.012). Conclusion: There is a relationship between the Anxiety Level and Knowledge of Pregnant Women in the third trimester with Readiness for Childbirth during the COVID-19 Pandemic  

scholarly journals FINANCIAL INSTRUMENTS AND THEIR IMPACT ON THE GROWTH OF INVESTMENT – A STUDY ON THE LIBYAN MARKET

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Abdulbaset Ali Alhaj ◽  
Abdullah Mohammed Awn ◽  
Al Taher Khalifa Abdusalam Alaswed
Keyword(s):  
Output Growth ◽  
Independent Effect ◽  
Financial Instruments ◽  
Domestic Investment ◽  
Short Time ◽  
Investment Growth ◽  
The Relationship ◽  
Limited Choice ◽  
Made In

Purpose: The aim of this study was to explore the relationship between Financial instruments and growth of investment. Design/Methodology/Approach: The distributed questionnaires include 300 clients from banks and companies represented in Tripoli. The data collected was analyzed using SPSS- SEM. Results: The obtained results showed that indicated that, despite the modest progress made in a very short time regarding all indicators which the paper calculated, however, it can be said that Libyan stock market remain largely underdeveloped, small and relatively inefficient. Its market capitalization to GDP is very low and investors have no access to long-term capital. In addition, the market still has very low liquidity and investors still have a limited choice of financial instruments and face liquidity problems. Originality/Value: This study contributes significantly to the importance of diversity in the use of financial instruments that help in the growth of investment. The study added a new discussion, which is the disclosure that financial instruments affect the growth of domestic investment, especially by easing financing restrictions, which allows companies to increase investment in response to increased demand for production. The main finding is that the structure of the financial system does not have an independent effect on investment growth, in the sense that it does not enhance the response of investment to changes in production, whereas financial development makes investment more responsive to output growth. Thus, instead of promoting a specific type of financial instrument, countries should implement policies that reduce transaction costs in financial intermediation and enforce the rights of creditors and investors. This will facilitate the development of banks and stock markets, which will stimulate the growth of domestic investment. JEL: D53; G14; O16

scholarly journals Estimation of Blood Pressure in the Radial Artery Using Strain-Based Pulse Wave and Photoplethysmography Sensors

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 556 ◽  
Author(s):  
Yu-Jen Wang ◽  
Chia-Hsien Chen ◽  
Chung-Yang Sue ◽  
Wen-Hsien Lu ◽  
Yee-Hsuan Chiou
Keyword(s):  
Blood Pressure ◽  
Radial Artery ◽  
Strain Gauge ◽  
Pulse Wave ◽  
Estimation Method ◽  
Force Sensor ◽  
Pressing Force ◽  
The Relationship ◽  
Vascular Status

Blood pressure (BP) is a crucial indicator of cardiac health and vascular status. This study explores the relationship between radial artery BP and wrist skin strain. A BP estimation method based on the physical model of wrist skin tissues and pulse wave velocity (PWV) is proposed. A photoplethysmography (PPG) sensor and strain gauge are used in this method. The developed strain-based pulse wave sensor consists of a pressing force sensor, which ensures consistent pressing force, and a strain gauge, which measures the cardiac pulsation on the wrist skin. These features enable long-term BP monitoring without incurring the limb compression caused by a cuff. Thus, this method is useful for individuals requiring continuous BP monitoring. In this study, the BP of each participant was measured in three modes (before, during, and after exercise), and the data were compared using a clinically validated sphygmomanometer. The percentage errors of diastolic and systolic BP readings were, respectively, 4.74% and 4.49% before exercise, 6.38% and 6.10% during exercise, and 5.98% and 4.81% after a rest. The errors were compared with a clinically validated sphygmomanometer.

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