scholarly journals An Improved Initialization Method for Monocular Visual-Inertial SLAM

Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3063
Author(s):  
Jun Cheng ◽  
Liyan Zhang ◽  
Qihong Chen
Keyword(s):  
Iterative Method ◽  
Measurement Model ◽  
The Self ◽  
Experimental Results ◽  
Positioning Accuracy ◽  
Scale Estimation ◽  
Vision Measurement ◽  
Localization And Mapping ◽  
Initial Stage ◽  
Robot Platform

In the aim of improving the positioning accuracy of the monocular visual-inertial simultaneous localization and mapping (VI-SLAM) system, an improved initialization method with faster convergence is proposed. This approach is classified into three parts: Firstly, in the initial stage, the pure vision measurement model of ORB-SLAM is employed to make all the variables visible. Secondly, the frequency of the IMU and camera was aligned by IMU pre-integration technology. Thirdly, an improved iterative method is put forward for estimating the initial parameters of IMU faster. The estimation of IMU initial parameters is divided into several simpler sub-problems, containing direction refinement gravity estimation, gyroscope deviation estimation, accelerometer bias, and scale estimation. The experimental results on the self-built robot platform show that our method can up-regulate the initialization convergence speed, simultaneously improve the positioning accuracy of the entire VI-SLAM system.

scholarly journals An Improved Initialization Method for Monocular Visual-Inertial SLAM

2021 ◽  
Author(s):  
Cheng Jun ◽  
Zhang Liyan ◽  
Chen Qihong
Keyword(s):  
Iterative Method ◽  
Measurement Model ◽  
The Self ◽  
Experimental Results ◽  
Positioning Accuracy ◽  
Scale Estimation ◽  
Vision Measurement ◽  
Localization And Mapping ◽  
Initial Stage ◽  
Robot Platform

In the aim of improving the positioning accuracy of monocular visual inertial simultaneous localization and mapping (VI-SLAM) system, an improved initialization method with faster convergence is proposed. This approach is classified as three parts: Firstly, in the initial stage, the pure vision measurement model of ORB-SLAM is employed to make all the variables visible. Secondly, the frequency of IMU camera was aligned by IMU preintegration technology. Thirdly, an improved iterative method is put forward for estimating the initial parameters of IMU faster. The estimation of IMU initial parameters is divided into several simpler sub-problems, containing direction refinement gravity estimation, gyroscope deviation estimation, accelerometer bias and scale estimation. The experimental results on the self-built robot platform show that our method can up-regulate the initialization convergence speed, simultaneously improve the positioning accuracy of the entire VI-SLAM system.

Self-Calibration of Coupling Error for 3-DOF Displacement Measurement of Planar Working Stage Based on Two Planar Gratings

2017 ◽  
Vol 870 ◽  
pp. 135-140
Author(s):  
Yong Meng Liu ◽  
Ze Lin Li ◽  
De Hao Du ◽  
Mao Qiang Yuan ◽  
Jing Zhi Huang ◽  
...  
Keyword(s):  
Fourier Series ◽  
Calibration Method ◽  
Systematic Errors ◽  
Displacement Measurement ◽  
The Self ◽  
Experimental Results ◽  
Positioning Accuracy ◽  
Self Calibration ◽  
Coupling Error

A self-calibration method of coupling error is presented for 3-DOF displacement measurement of a planar moving stage based on two planar gratings. The self-calibration method using Fourier series is developed to extract the periodic systematic errors from the coupling errors. The extracted periodic systematic errors are compensated. Experiments are conducted to validate the validity of the self-calibration method and experimental results indicate that the coupling errors in x and y directions are reduced by 2 and 1.5 times respectively. It can be therefore concluded that the self-calibration method is suitable for the 3-DOF displacement measurement of a planar moving stage to improve the positioning accuracy.

CAD Analysis Applied to Self-Centering Compliant Grippers

2013 ◽  
Vol 325-326 ◽  
pp. 305-309 ◽  
Author(s):  
Stergios Ganatsios ◽  
Alina Spanu ◽  
Octavian Dontu ◽  
Daniel Besnea ◽  
Gheorghe I. Gheorghe
Keyword(s):  
Elastic Properties ◽  
Three Dimensional ◽  
The Self ◽  
Experimental Results ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Positioning Accuracy ◽  
Compliant Joints ◽  
Fem Method ◽  
Object Movement

The self centering grasping mechanisms aim to improve the positioning accuracy of the object movement. The paper presents the FEM method applied to such mechanism using compliant joints with elastic properties. We have studied the tensions and displacements for the three dimensional model and the experimental results achieved the goal of our work.

POS Supported ADS40/80 Imagery Direct Geo-Positioning and Positioning Accuracy Optimization

2014 ◽  
Vol 989-994 ◽  
pp. 3534-3539
Author(s):  
Yan Zhang ◽  
Tao Wang ◽  
Wu Fa Feng ◽  
Yong Hong Fan ◽  
Jie Rui
Keyword(s):  
Error Model ◽  
Bundle Adjustment ◽  
The Self ◽  
Experimental Results ◽  
Positioning Accuracy ◽  
Imaging Parameters ◽  
Array Sensor ◽  
Self Calibration ◽  
Line Array ◽  
Set Up

On the basis of establishing direct geo-positioning model for three-line array sensor ADS40/80 images, in order to optimize the positioning accuracy, the self-calibration technology was used to update the ADS40/80 sensor imaging parameters. Moreover, the ADS40/80 camera error model and self-calibration bundle adjustment model were set up. Multi-groups of ADS40 data over the Songshan experimental field were used for direct geo-positioning and parameter updating experiments. Experimental results proved that the self-calibration adjustment technique can effectively update sensor imaging parameters and significantly improve image direct positioning accuracy.

Psychological barriers of the initial stage of professional activity of the self–employed

2020 ◽  
Author(s):  
Ekaterina Galkina ◽  
Keyword(s):  
Individual Case ◽  
Professional Culture ◽  
The Self ◽  
Entrepreneurial Activity ◽  
Professional Activity ◽  
Interpretive Phenomenology ◽  
Financial Responsibility ◽  
Psychological Barriers ◽  
Initial Stage ◽  
The Subject

The problem of the study is that it is not sufficiently studied what psychological barriers people face at the initial stage of professional activity as self-employed. The aim of the study is to study the features of psychological barriers at the initial stage of professional activity of self-employed people. Research hypothesis: at the initial stage of professional activity as self-employed people face psychological barriers in the organizational and creative areas of entrepreneurial activity. The problem of psychological barriers was considered in their works by S. Rubinstein, N. Podymov, I. Pavlov, R. Shakurov and others. The article formulates particular definitions of the main concepts. Methodology: analysis of an individual case using interviews with processing in the framework of interpretive phenomenology. Respondent: female, 34 years old, self-employed as a psychologist for 1 year. Results: psychological barrier of accepting financial responsibility, barrier of adherence to a certain professional culture, barrier of competence in the profession. Certain psychological barriers can arise in connection with certain underlying medical conditions. The conclusions are that psychological barriers are a complex mental education, can be overcome in stages, and motivation of the subject is important for overcoming barriers.

Lateral Tire Forces on Wet Roads

1977 ◽  
Vol 5 (2) ◽  
pp. 75-82 ◽  
Author(s):  
A. Schallamach
Keyword(s):  
Normal Load ◽  
The Self ◽  
Experimental Results ◽  
Slip Angle ◽  
Tire Model ◽  
Side Force ◽  
Tire Forces

Abstract Expressions are derived for side force and self-aligning torque of a simple tire model on wet roads with velocity-dependent friction. The results agree qualitatively with experimental results at moderate speeds. In particular, the theory correctly predicts that the self-aligning torque can become negative under easily realizable circumstances. The slip angle at which the torque reverses sign should increase with the normal load.

Friction and Tribological Considerations for Nanometer Range Machining

2001 ◽  
Author(s):  
Som Chattopadhyay
Keyword(s):  
Mathematical Model ◽  
High Precision ◽  
Local Deformation ◽  
Experimental Results ◽  
Precision Machining ◽  
Complex Motion ◽  
Positioning Accuracy ◽  
Nanometer Range ◽  
Motion Characteristic ◽  
Low Speeds

Abstract Positioning accuracy within the range of nanometers is required for high precision machining applications. The implementation of such a range is difficult through the slides because of (a) irregular nature of friction at the slider-guideway interface, and (b) complex motion characteristic at very low speeds. The complexity arises due to the local deformation at the interface prior to breakaway, which is known as microdynamics. In this work prior experimental results exhibiting microdynamics have been appraised, and mathematical model developed to understand this behavior.

RAMAN SPECTRA OF THE H2SO4–SO3 AND D2SO4–SO3 SYSTEMS: EVIDENCE FOR THE OCCURRENCE OF POLYSULPHURIC ACIDS

1962 ◽  
Vol 40 (4) ◽  
pp. 658-674 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Sulphuric Acid ◽  
Raman Spectra ◽  
Ionic Species ◽  
The Self ◽  
Experimental Results ◽  
Similar Work ◽  
Stretching Vibrations ◽  
Sulphur Trioxide ◽  
High Concentrations

The Raman spectra of oleums, i.e. mixtures of sulphur trioxide and sulphuric acid, have been re-examined. Similar measurements on the sulphur trioxide – deuterosulphuric acid (D2SO4) system are also reported. The experimental results and conclusions of previous similar work on oleums are discussed. By comparison of the spectra of oleums with those of the polysulphuryl halides it is shown that the polysulphuric acids H2S2O7 and H2S3O10 are present in this system. The increase in the frequency of the SO2 stretching vibrations with increasing concentration of sulphur trioxide gives evidence for the existence of higher polysulphuric acids such as H2S4O13 at high concentrations of sulphur trioxide. In relatively concentrated oleum, sulphur trioxide monomer and trimer are also present. It is shown that the self-dissociation of liquid H2S2O7 gives mainly molecular H2S2O10 and H2SO4 and not ionic species. The conclusions reached from the interpretation of the Raman spectra of the D2SO4–SO3 system are similar to those arrived at for sulphuric acid oleums. The spectra of solutions of NaHSO4 in oleums were also examined, and are discussed.

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