scholarly journals A Multi-Feature Fusion Slam System Attaching Semantic Invariant to Points and Lines

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1196
Author(s):  
Gang Li ◽  
Yawen Zeng ◽  
Huilan Huang ◽  
Shaojian Song ◽  
Bin Liu ◽  
...  
Keyword(s):  
Feature Matching ◽  
Feature Fusion ◽  
Error Function ◽  
Line Segments ◽  
Cumulative Error ◽  
Localization And Mapping ◽  
Tracking Process ◽  
Line Features ◽  
Point Line ◽  
Segment Data

The traditional simultaneous localization and mapping (SLAM) system uses static points of the environment as features for real-time localization and mapping. When there are few available point features, the system is difficult to implement. A feasible solution is to introduce line features. In complex scenarios containing rich line segments, the description of line segments is not strongly differentiated, which can lead to incorrect association of line segment data, thus introducing errors into the system and aggravating the cumulative error of the system. To address this problem, a point-line stereo visual SLAM system incorporating semantic invariants is proposed in this paper. This system improves the accuracy of line feature matching by fusing line features with image semantic invariant information. When defining the error function, the semantic invariant is fused with the reprojection error function, and the semantic constraint is applied to reduce the cumulative error of the poses in the long-term tracking process. Experiments on the Office sequence of the TartanAir dataset and the KITTI dataset show that this system improves the matching accuracy of line features and suppresses the cumulative error of the SLAM system to some extent, and the mean relative pose error (RPE) is 1.38 and 0.0593 m, respectively.

Improvement of Variation Propagation Control in Mechanical Assembly Using Adjustment Assembly Technique

2017 ◽  
Vol 870 ◽  
pp. 459-464 ◽  
Author(s):  
Chuan Zhi Sun ◽  
Lei Wang ◽  
Jiu Bin Tan ◽  
Bo Zhao ◽  
Guo Liang Jin ◽  
...  
Keyword(s):  
Assembly Model ◽  
Mechanical Assembly ◽  
Assembly Quality ◽  
Cumulative Error ◽  
Assembly Method ◽  
Variation Propagation ◽  
Rotationally Symmetric ◽  
Aero Engine ◽  
Assembly Technique ◽  
Engine Components

This paper aims to provide an assembly method to improve mechanical assembly quality. In order to improve the variation propagation control in rotationally symmetric cylindrical components assembly, the eccentric and tilt errors of a single rotor stage were taken into account using a connective assembly model and the eccentric deviation in a mechanical assembly was minimized by properly selecting component orientations. Compared to the minimum cumulative error, the maximum cumulative error was reduced by 71 percent, and the average cumulative error was reduced by 57 percent in the assembly of three components. This article provides an assembly method through variation propagation control in rotationally symmetric cylindrical components assembly. The method could be extended to rotationally symmetric cylindrical components assembly, for example in the assembly of aero-engine components.

scholarly journals The Assisted Positioning Technology for High Speed Train Based on Deep Learning

2020 ◽  
Vol 10 (23) ◽  
pp. 8625
Author(s):  
Yali Song ◽  
Yinghong Wen
Keyword(s):  
Deep Learning ◽  
High Speed ◽  
Detection Method ◽  
Generative Adversarial Networks ◽  
Single Shot ◽  
High Speed Train ◽  
Data Set ◽  
Detection Model ◽  
Model Based ◽  
Cumulative Error

In the positioning process of a high-speed train, cumulative error may result in a reduction in the positioning accuracy. The assisted positioning technology based on kilometer posts can be used as an effective method to correct the cumulative error. However, the traditional detection method of kilometer posts is time-consuming and complex, which greatly affects the correction efficiency. Therefore, in this paper, a kilometer post detection model based on deep learning is proposed. Firstly, the Deep Convolutional Generative Adversarial Networks (DCGAN) algorithm is introduced to construct an effective kilometer post data set. This greatly reduces the cost of real data acquisition and provides a prerequisite for the construction of the detection model. Then, by using the existing optimization as a reference and further simplifying the design of the Single Shot multibox Detector (SSD) model according to the specific application scenario of this paper, the kilometer post detection model based on an improved SSD algorithm is established. Finally, from the analysis of the experimental results, we know that the detection model established in this paper ensures both detection accuracy and efficiency. The accuracy of our model reached 98.92%, while the detection time was only 35.43 ms. Thus, our model realizes the rapid and accurate detection of kilometer posts and improves the assisted positioning technology based on kilometer posts by optimizing the detection method.

scholarly journals Application of microwave motion sensors in navigation systems for ground vehicle

2019 ◽  
Vol 30 ◽  
pp. 12004 ◽  
Author(s):  
Dmitrii Khablov
Keyword(s):  
Navigation System ◽  
Autonomous Navigation ◽  
Velocity Vector ◽  
Continuous Measurement ◽  
Navigation Systems ◽  
Motion Sensors ◽  
Ground Vehicle ◽  
Cumulative Error ◽  
System A ◽  
Transport Management

Effective land transport management in a controlled and unmanned mode is impossible without its accurate and continuous positioning. The paper discusses the possibility of increasing this accuracy in the absence or uncertain reception of signals from satellites of the global navigation system. Moreover, the use of an additional self-navigation inertial system to solve this problem in this case is not justified for reasons of accuracy and cost. Therefore, as an alternative autonomous navigation system, a solution based on radar Doppler sensors of modular type is proposed. The methods of measuring the velocity vector and the algorithm of direct continuous measurement of displacements are considered. It is shown that the latter measurement option can significantly reduce the cumulative error when positioning vehicles.

DISCUSSION ON: LATERAL VELOCITY VARIATIONS NEAR BOREHOLES

Geophysics ◽  
1959 ◽  
Vol 24 (3) ◽  
pp. 461-462
Author(s):  
J. A. Brooks
Keyword(s):  
High Velocity ◽  
Travel Times ◽  
Lateral Velocity ◽  
Travel Path ◽  
Cumulative Error ◽  
Velocity Variations

The requirement that integrated vertical times from a continuous velocity log check to within some small percent the vertical times computed from the observed travel times of a geophone survey in the same borehole is to me unreasonable. Although we geophysicists know that there are inherent errors in the results of geophone surveys because of possible errors in weathering velocity corrections, datum velocity corrections, depth of shot corrections, and especially seismic travel‐path assumptions, we have presumed the cumulative error in all but unusual surveys to be within the limits of accuracy of reflection seismograph interpretation. The usual seismic travel path assumption, particularly in areas of high velocity stringers or velocity inversions, can be very treacherous in the computation of vertical times. Consequently, I cannot understand why some of our colleagues insist that the log results are incorrect unless they check very closely with the computed vertical shot times. Maybe the computed times are wrong!

Sign in / Sign up

Export Citation Format

Share Document