scholarly journals Precise Linear Positioning Method Based on Transmissive Two-Stage Diffraction Grating System

2021 ◽  
Vol 2083 (2) ◽  
pp. 022037
Author(s):  
Jin Lu ◽  
Jiannan Lu ◽  
Jun Ma ◽  
Zaiyan Gong
Keyword(s):  
Diffraction Grating ◽  
Simulation Experiment ◽  
Two Stage ◽  
Positioning Accuracy ◽  
Precise Positioning ◽  
Differential Positioning ◽  
Positioning Method ◽  
Positioning Device ◽  
Grating Diffraction ◽  
The Mathematical Model

Abstract This paper mainly studies the precise linear positioning method based on the transmissive type two-stage diffraction grating system. Starting from the analysis of the two-stage diffraction principle, the mathematical model of the two-stage grating diffraction is established, and the positioning characteristics of the differential positioning method and the modified positioning method are discussed. The simulation experiment of the linear positioning device is carried out to study the displacement characteristics. The experimental results show that the precise positioning based on the diffraction grating can obtain a positioning accuracy of ±0.4 μm.

Study on the Multi-Optical Theodolites Positioning Method Based on Function Restriction

2014 ◽  
Vol 511-512 ◽  
pp. 227-233
Author(s):  
Zhi Hua Gong ◽  
Peng Wei Duan ◽  
Xu Xu ◽  
Hai Dong Lv
Keyword(s):  
Data Fusion ◽  
Simulation Experiment ◽  
Classical Method ◽  
Engineering Application ◽  
Reference Value ◽  
Fusion Method ◽  
Traditional Methods ◽  
Positioning Accuracy ◽  
Positioning Method ◽  
Optical Theodolite

Aiming at the shortcoming of the classical method of optical theodolite projection intersection named ́R ́ method and traditional data fusion method named point-by-point EMBET method, this paper advances the function restriction EMBET method which is based on multi-optical theodolites. Comparing with the three methods by simulation experiment, it demonstrates that the function restriction EMBET method has higher positioning accuracy and stronger practicability than two traditional methods. Furthermore, this method supplies the important reference value for engineering application.

scholarly journals BDS/GPS INTEGRATED POSITIONING METHOD RESEARCH BASED ON NONLINEAR KALMAN FILTERING

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 531-535
Author(s):  
Y. Ma ◽  
W. Yuan ◽  
H. Sun
Keyword(s):  
Kalman Filter ◽  
Unscented Kalman Filter ◽  
Phase Measurement ◽  
Signal Attenuation ◽  
Carrier Phase Measurement ◽  
Positioning Accuracy ◽  
Positioning Method ◽  
Nonlinear Kalman Filtering ◽  
The Mathematical Model ◽  
Better Than

In order to realize fast and accurate BDS/GPS integrated positioning, it is necessary to overcome the adverse effects of signal attenuation, multipath effect and echo interference to ensure the result of continuous and accurate navigation and positioning. In this paper, pseudo-range positioning is used as the mathematical model. In the stage of data preprocessing, using precise and smooth carrier phase measurement value to promote the rough pseudo-range measurement value without ambiguity. At last, the Extended Kalman Filter(EKF), the Unscented Kalman Filter(UKF) and the Particle Filter(PF) algorithm are applied in the integrated positioning method for higher positioning accuracy. The experimental results show that the positioning accuracy of PF is the highest, and UKF is better than EKF.

scholarly journals Rail Fastener Positioning Based on Double Template Matching

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yijin Qiu ◽  
Xingjie Chen ◽  
Zhaomin Lv
Keyword(s):  
Template Matching ◽  
Two Dimensions ◽  
Original Image ◽  
Positioning Accuracy ◽  
Precise Positioning ◽  
Horizontal Dimension ◽  
Positioning Strategy ◽  
Template Image ◽  
Positioning Method ◽  
Coarse To Fine

For global template matching (GTM), which is commonly used in the positioning of rail fasteners, only the fastener template is used to search the global image in both two dimensions, which will result in errors in two dimensions, and the lower positioning accuracy will be caused. A positioning method for rail fasteners based on double template matching (DTM) is proposed in this paper, in which the double template contains the rail template and the fastener template. First, the rail template is used to scan the original image in horizontal dimension, and the squared Euclidean distance (SED) is used to obtain the rail positioning in the original image. Combining with the prior knowledge of the fastener template image, the image composed of the rail and the fastener can be obtained, which is called the Rail Area Map (RAM) in this paper. Then, after preprocessing the RAM and the fastener template image, the fastener template image is used to scan the RAM in vertical dimension, and the normalized correlation coefficient (NCC) is used to calculate the similarity between the template and the subgraph of the RAM to achieve precise positioning of the fastener. The proposed DTM method adopts a positioning strategy from coarse to fine, and two templates are used to complete different positioning tasks in their own dimension, respectively. Due to the rail can be precise positioned in horizontal dimension, the error of the fastener positioning in the horizontal dimension can be avoided, and thus, the positioning accuracy can be improved. Experiments on the on-site line fastener images prove that the proposed method can effectively achieve the precise positioning of fasteners.

Precise positioning method for multi-process connecting based on binocular vision

2016 ◽  
Author(s):  
Wei Liu ◽  
Lichao Ding ◽  
Kai Zhao ◽  
Xiao Li ◽  
Ling Wang ◽  
...  
Keyword(s):  
Binocular Vision ◽  
Precise Positioning ◽  
Positioning Method

scholarly journals Fingerprinting Acoustic Localization Indoor Based on Cluster Analysis and Iterative Interpolation

2018 ◽  
Vol 8 (10) ◽  
pp. 1862 ◽  
Author(s):  
Shuopeng Wang ◽  
Peng Yang ◽  
Hao Sun
Keyword(s):  
Cluster Analysis ◽  
Interpolation Method ◽  
Reference Points ◽  
Matching Method ◽  
Two Stage ◽  
Positioning Accuracy ◽  
Acoustic Localization ◽  
Database Construction ◽  
Iterative Interpolation ◽  
Stage Matching

Fingerprinting acoustic localization usually requires tremendous time and effort for database construction in sampling phase and reference points (RPs) matching in positioning phase. To improve the efficiency of this acoustic localization process, an iterative interpolation method is proposed to reduce the initial RPs needed for the required positioning accuracy by generating virtual RPs in positioning phase. Meanwhile, a two-stage matching method based on cluster analysis is proposed for computation reduction of RPs matching. Results reported show that, on the premise of ensuring positioning accuracy, two-stage matching method based on feature clustering partition can reduce the average RPs matching amount to 30.14% of the global linear matching method taken. Meanwhile, the iterative interpolation method can guarantee the positioning accuracy with only 27.77% initial RPs of the traditional method needed.

scholarly journals Indoor Positioning Method Based on Infrared Vision and UWB Fusion

2021 ◽  
Vol 2078 (1) ◽  
pp. 012070
Author(s):  
Qianrong Zhang ◽  
Yi Li
Keyword(s):  
Real Time ◽  
Indoor Localization ◽  
Low Cost ◽  
Ultra Wideband ◽  
Coverage Area ◽  
Positioning Accuracy ◽  
Mobile Vehicle ◽  
Positioning Method ◽  
Positioning Algorithm ◽  
Infrared Vision

Abstract Ultra-wideband (UWB) has broad application prospects in the field of indoor localization. In order to make up for the shortcomings of ultra-wideband that is easily affected by the environment, a positioning method based on the fusion of infrared vision and ultra-wideband is proposed. Infrared vision assists locating by identifying artificial landmarks attached to the ceiling. UWB uses an adaptive weight positioning algorithm to improve the positioning accuracy of the edge of the UWB positioning coverage area. Extended Kalman filter (EKF) is used to fuse the real-time location information of the two. Finally, the intelligent mobile vehicle-mounted platform is used to collect infrared images and UWB ranging information in the indoor environment to verify the fusion method. Experimental results show that the fusion positioning method is better than any positioning method, has the advantages of low cost, real-time performance, and robustness, and can achieve centimeter-level positioning accuracy.

scholarly journals On using the rotor acceleration mode to increase the accuracy of a two-stage gyrocompass

2020 ◽  
pp. 5-13
Author(s):  
Volodymyr Fedorov ◽  
Vladislav Kikot ◽  
Nataliya Shtefan
Keyword(s):  
Mathematical Model ◽  
Initial Position ◽  
Effect Of Temperature ◽  
Two Stage ◽  
Best Estimate ◽  
Torsion Suspension ◽  
Measured Angle ◽  
State Position ◽  
Acceleration Mode ◽  
The Mathematical Model

The article considers a two-stage gyrocompass with a rigid torsion suspension of the moving part. The principle of its action is based on balancing the elastic moment of the torsion bars with the gyroscopic moment. When this condition is met, the azimuth of the steady-state position of the rotor axis is calculated from the known kinetic moment , latitude and angular rigidity of the torsion bars, and the measured angle of rotation of the moving part of the gyroscope relative to its initial position. The “aging of the material” of the torsion bars, the effect of temperature on them, etc., leads to an uncontrolled change in the angular stiffness of the torsion bars, which, in turn, leads to an error in determining the position of the meridian. A method is proposed for determining the position of the meridian under conditions when the angular stiffness of the torsion is unknown. The method involves observing the motion of the gyroscope in a mode where the kinetic momentum changes linearly (the rotor accelerates). This movement is associated with the movement of the mathematical model of a two-stage gyrocompass in the same mode in the form of a differential equation of motion or in the form of its solution. As a result of minimizing the discrepancy between the real movement of the gyrocompass and the movement of its mathematical model, the “best estimate” of the parameter characterizing the position of the meridian and the “best estimate” of the angular stiffness of the torsion bars in this dimension are found. The results of modeling the corresponding information processing algorithms are considered. The advantages of the proposed method compared with traditional methods are indicated .

scholarly journals Application of a WiFi/Geomagnetic Combined Positioning Method in a Single Access Point Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Hongbin Pan ◽  
Yang Xiang ◽  
Jian Xiong ◽  
Yifan Zhao ◽  
Ziwei Huang ◽  
...  
Keyword(s):  
Nearest Neighbor ◽  
Detection Method ◽  
Access Point ◽  
Combination Method ◽  
Data Set ◽  
Positioning Accuracy ◽  
Multipath Effects ◽  
Positioning Method ◽  
Fingerprint Database ◽  
Mismatch Rate

Because of the particularity of urban underground pipe corridor environment, the distribution of wireless access points is sparse. It causes great interference to a single WiFi positioning method or geomagnetic method. In order to meet the positioning needs of daily inspection staff, this paper proposes a WiFi/geomagnetic combined positioning method. In this combination method, firstly, the collected WiFi strength data was filtered by outlier detection method. Then, the filtered data set was used to construct the offline fingerprint database. In the following positioning operation, the classical k -nearest neighbor algorithm was firstly used for preliminary positioning. Then, a standard circle was constructed based on the points obtained by the algorithm and the actual coordinate points. The diameter of the standard circle was the error, and the geomagnetic data were used for more accurate positioning in this circle. The method reduced the WiFi mismatch rate caused by multipath effects and improved positioning accuracy. Finally, a positioning accuracy experiment was performed in a single AP distribution environment that simulates a pipe corridor environment. The results proves that the WiFi/geomagnetic combined positioning method proposed in this paper is superior to the traditional WiFi and geomagnetic positioning methods in terms of positioning accuracy.

scholarly journals An Improved Hierarchical WLAN Positioning Method Based on Apriori Knowledge

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 475 ◽  
Author(s):  
Kwo-Ting Fang ◽  
Cheng-Tao Lee ◽  
Li-min Sun
Keyword(s):  
Compressive Sensing ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Signal Reconstruction ◽  
Local Area ◽  
Area Network ◽  
Fingerprint Matching ◽  
Positioning Accuracy ◽  
Positioning Method ◽  
Fine Localization

The hierarchical-based structure is recognized as a favorable structure for wireless local area network (WLAN) positioning. It is comprised of two positioning phases: the coarse localization phase and the fine localization phase. In the coarse localization phase, the users’ positions are firstly narrowed down to smaller regions or clusters. Then, a fingerprint matching algorithm is adopted to estimate the users’ positions within the clusters during the fine localization phase. Currently the clustering strategies in the coarse localization phase can be divided into received signal strength (RSS) clustering and 3D clustering. And the commonly seen positioning algorithms in the fine localization phase include k nearest neighbors (kNN), kernel based and compressive sensing-based. This paper proposed an improved WLAN positioning method using the combination: 3D clustering for the coarse localization phase and the compressive sensing-based fine localization. The method have three favorable features: (1) By using the previously estimated positions to define the sub-reference fingerprinting map (RFM) in the first coarse localization phase, the method can adopt the prior information that the users’ positions are continuous during walking to improve positioning accuracy. (2) The compressive sensing theory is adopted in the fine localization phase, where the positioning problem is transformed to a signal reconstruction problem. This again can improve the positioning accuracy. (3) The second coarse localization phase is added to avoid the global fingerprint matching in traditional 3D clustering-based methods when the stuck-in-small-area problem is encountered, thus, sufficiently lowered the maximum positioning latency. The proposed improved hierarchical WLAN positioning method is compared with two traditional methods during the experiments section. The resulting positioning accuracy and positioning latency have shown that the performance of the proposed method has better performance in both aspects.

scholarly journals Fog Computing-Based Differential Positioning Method for BDS

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Lina Wang ◽  
Linlin Li
Keyword(s):  
Fog Computing ◽  
Satellite Navigation ◽  
Original Data ◽  
Mobility Support ◽  
Positioning Systems ◽  
Satellite Navigation System ◽  
Differential Positioning ◽  
Positioning Method ◽  
Positioning Algorithm ◽  
Positioning Time

As one of the four global satellite navigation and positioning systems, BeiDou satellite navigation system (BDS) has received increasingly more attention. The differential positioning technology of BDS has greatly enhanced its accuracy and meets the needs of high-precision applications, but its positioning time still has much room for improvement. Fog computing allows the use of its services with low latency and mobility support to make up for the disadvantages of differential positioning algorithm. The paper proposes the fog computing-based differential positioning (FCDP) method which introduces fog computing technology to BDS. Compared with the original data center-based differential positioning (DCDP) method, the simulation results demonstrate that the FCDP method decreases the latency of positioning, while assuring the positioning accuracy.

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