scholarly journals Optimization of Time Synchronization and Algorithms with TDOA Based Indoor Positioning Technique for Internet of Things

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6513
Author(s):  
Kun Zhao ◽  
Tiantian Zhao ◽  
Zhengqi Zheng ◽  
Chao Yu ◽  
Difeng Ma ◽  
...  
Keyword(s):  
Internet Of Things ◽  
High Precision ◽  
Time Synchronization ◽  
Indoor Positioning ◽  
Least Square ◽  
Ultra Wideband ◽  
Positioning Error ◽  
Time Difference Of Arrival ◽  
Positioning Technique ◽  
Synchronization Performance

To provide high-precision positioning for Internet of Things (IoT) scenarios, we optimize the indoor positioning technique based on Ultra-Wideband (UWB) Time Difference of Arrival (TDOA) equipment. This paper analyzes sources of positioning error and improves the time synchronization algorithm based on the synchronization packet. Then we use the labels of the known position to further optimize the time synchronization performance, and hence improve TDOA measurements. After time synchronization optimization, a Weighted Least Square (WLS) and Taylor coordination algorithm is derived. Experiments show that our optimization reduces the average positioning error from 54.8 cm to 12.6 cm.

scholarly journals A Novel High Precision and Low Consumption Indoor Positioning Algorithm for Internet of Things

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 86874-86883 ◽  
Author(s):  
Jin Ren ◽  
Yunan Wang ◽  
Changliu Niu ◽  
Wei Song
Keyword(s):  
Internet Of Things ◽  
High Precision ◽  
Indoor Positioning ◽  
Positioning Algorithm ◽  
Low Consumption

scholarly journals TOF-Based Fast Self-Positioning Algorithm for UWB Mobile Base Stations

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6359
Author(s):  
Yuxiang Han ◽  
Xiaoming Zhang ◽  
Zhengxi Lai ◽  
Yuchen Geng
Keyword(s):  
Local Coordinate System ◽  
Base Station ◽  
Least Square ◽  
Base Stations ◽  
Ultra Wideband ◽  
Positioning Error ◽  
Position Measurement ◽  
Propagation Law ◽  
Positioning Algorithm ◽  
Mobile Base

To solve the problem of heavy workload and high cost when acquiring the position of Ultra-Wideband (UWB) mobile base stations in sports fields, a fast self-positioning algorithm for UWB mobile base stations algorithm based on Time of Flight (TOF) is proposed. First, according to the layout of the base stations in the sports field, the local coordinate system is determined, and an equation based on the ranging information between the base stations is established; the Least Square method is used to calculate the coordinates of each base station, and the Newton Iteration method is used to converge the positioning results. Then the origin and propagation law of positioning error, as well as the method of reducing the positioning error are analyzed. The simulation data and experimental results show that the average positioning accuracy of the mobile base station is within 0.05 m, which meets the expected accuracy of the base station position measurement. Compared with traditional manual measurement methods, base station self-positioning can effectively save deployment time and reduce workload.

scholarly journals A High-Precision Energy-Efficient GPS Time-Sync Method for High-Density Seismic Surveys

2020 ◽  
Vol 10 (11) ◽  
pp. 3768
Author(s):  
Ruyun Tian ◽  
Junjie Zhang ◽  
Shuai Zhang ◽  
Longxu Wang ◽  
Hongyuan Yang ◽  
...  
Keyword(s):  
High Precision ◽  
Seismic Data ◽  
Energy Efficient ◽  
Time Synchronization ◽  
High Density ◽  
Seismic Survey ◽  
Data Synchronization ◽  
Synchronization Method ◽  
Synchronization Accuracy ◽  
Synchronization Performance

Large numbers of seismic channels and high-density energy-efficient acquisition systems are the development trend of seismic instruments and have attracted high R&D interests in recent years. The combination of remote sensing and wireless sensor network technology provides superior observation capabilities for high-density seismic exploration. However, large-scale and multi-node acquisition methods place higher requirements on time synchronization performance. Seismic data with poor time synchronization will cause considerable errors in the interpretation of seismic data and even have no practical significance. Thus, the strict time synchronization performance is the prerequisite and basis for the application of cable-less storage seismograph in high-density seismic array applications. The existing time synchronization methods have high power consumption and poor time synchronization accuracy, which is not suitable for the long-time task. In addition, these methods are affected by the number of nodes and the distance. This paper presents an energy-efficient time-sharing indexed interpolation intercept method for the seismic data synchronization. The time synchronization method uses the high-precision TCXO as the main clock and records GPS time in the SD card at intervals to achieve the high-precision time-stamp for the seismic data. Then the seismic data is intercepted intermittently based on precise time stamps, which achieves the strict seismic data synchronization. Performance analysis shows that the time synchronization accuracy of the proposed method is 0.6 μs and saves 73% energy of the time-sync periods compared to the common GPS timing method. The field measurement results indicate that the time synchronization accuracy is not associated with the working time and the distance between nodes so that the proposed synchronization method is suitable for the high-density seismic survey.

scholarly journals Mobile Synchronization Recovery for Ultrasonic Indoor Positioning

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 702 ◽  
Author(s):  
Riccardo Carotenuto ◽  
Massimo Merenda ◽  
Demetrio Iero ◽  
Francesco G. Della Corte
Keyword(s):  
Indoor Positioning ◽  
Time Difference Of Arrival ◽  
Refresh Rate ◽  
Positioning Accuracy ◽  
Ultrasonic Signals ◽  
Location Aware ◽  
Rf Signals ◽  
Fixed Reference ◽  
Positioning Technique ◽  
The Cost

The growing interest for indoor position-based applications and services, as well as ubiquitous computing and location aware information, have led to increasing efforts toward the development of positioning techniques. Many applications require accurate positioning or tracking of people and assets inside buildings, and some market sectors are waiting for such technologies for starting a fast growth. Ultrasonic systems have already been shown to possess the desired positioning accuracy and refresh rate. However, they still require accurate synchronization between ultrasound emitters and receivers to work properly. Usually, synchronization is carried out through radio frequency (RF) signals, adding system complexity and raising the cost. In this work, this limit is overcome by introducing a novel self-synchronizing indoor positioning technique. Ultrasonic signals travel from emitters placed at fixed reference positions to any number of mobile devices (MD). The travelled distance is computed from the time of flight (TOF), which requires in turn synchronism between emitter and receiver. It is shown that this synchronism can be indirectly estimated from the time difference of arrival (TDOA) of the ultrasonic signals. The obtained positioning information is private, in the sense that the positioning infrastructure is not aware of the number or identity of the MDs that use it. Computer simulations and experimental results obtained in a typical office room are provided.

Ultra Wideband Indoor Positioning Using Kalman Filters

2012 ◽  
Vol 433-440 ◽  
pp. 4207-4213 ◽  
Author(s):  
Li Zhang ◽  
Hao Zhang ◽  
Xue Rong Cui ◽  
T Aaron Gulliver
Keyword(s):  
Kalman Filter ◽  
Ultra Wideband ◽  
Line Of Sight ◽  
Time Difference Of Arrival ◽  
Positioning Systems ◽  
Positioning Technique ◽  
Performance Results ◽  
Source Of Error ◽  
Mitigation Technique ◽  
Non Line Of Sight

A time-difference-of-arrival (TDOA) positioning technique for indoor ultra wideband (UWB) systems is presented. Non-line-of-sight (NLOS) propagation error is a major source of error in positioning systems. Therefore an NLOS mitigation technique employing a Kalman filter is utilized to reduce the NLOS errors in indoor UWB environments. An extended Kalman filter (EKF) is used to process the TDOA data for mobile positioning and tracking. Performance results are presented which show that the proposed scheme can significantly improve the positioning accuracy in a UWB environment.

scholarly journals Performance evaluation of GPS / BDS combined single-point positioning based on RTKLIB

2020 ◽  
Vol 165 ◽  
pp. 03009
Author(s):  
Li Yan-yi ◽  
Huang Jin ◽  
Tang Ming-xiu
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Single Point ◽  
Least Square Method ◽  
Least Square ◽  
Filter Method ◽  
Single System ◽  
Positioning Error ◽  
Dual Mode ◽  
Kalman Filter Method

In order to evaluate the performance of GPS / BDS, RTKLIB, an open-source software of GNSS, is used in this paper. In this paper, the least square method, the weighted least square method and the extended Kalman filter method are respectively applied to BDS / GPS single system for data solution. Then, the BDS system and GPS system are used for fusion positioning and the positioning results of the two systems are compared with that of the single system. Through the comparison of experiments, on the premise of using the extended Kalman filter method for positioning, when the GPS signal is not good, BDS data is introduced for dual-mode positioning, the positioning error in e direction is reduced by 36.97%, the positioning error in U direction is reduced by 22.95%, and the spatial positioning error is reduced by 16.01%, which further reflects the advantages of dual-mode positioning in improving a system robustness and reducing the error.

scholarly journals High-Precision RTT-Based Indoor Positioning System Using RCDN and RPN

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3701
Author(s):  
Ju-Hyeon Seong ◽  
Soo-Hwan Lee ◽  
Won-Yeol Kim ◽  
Dong-Hoan Seo
Keyword(s):  
High Precision ◽  
Distance Estimation ◽  
Sampling Period ◽  
Multipath Fading ◽  
Indoor Positioning ◽  
Positioning System ◽  
Positioning Systems ◽  
Positioning Errors ◽  
Location Determination ◽  
Indoor Positioning System

Wi-Fi round-trip timing (RTT) was applied to indoor positioning systems based on distance estimation. RTT has a higher reception instability than the received signal strength indicator (RSSI)-based fingerprint in non-line-of-sight (NLOS) environments with many obstacles, resulting in large positioning errors due to multipath fading. To solve these problems, in this paper, we propose high-precision RTT-based indoor positioning system using an RTT compensation distance network (RCDN) and a region proposal network (RPN). The proposed method consists of a CNN-based RCDN for improving the prediction accuracy and learning rate of the received distances and a recurrent neural network-based RPN for real-time positioning, implemented in an end-to-end manner. The proposed RCDN collects and corrects a stable and reliable distance prediction value from each RTT transmitter by applying a scanning step to increase the reception rate of the TOF-based RTT with unstable reception. In addition, the user location is derived using the fingerprint-based location determination method through the RPN in which division processing is applied to the distances of the RTT corrected in the RCDN using the characteristics of the fast-sampling period.

scholarly journals A Security Management Architecture for Time Synchronization towards High Precision Networks

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Hongxing Li ◽  
Dengkui Li ◽  
Xiaodong Zhang ◽  
Guochu Shou ◽  
Yihong Hu ◽  
...  
Keyword(s):  
High Precision ◽  
Time Synchronization ◽  
Security Management ◽  
Management Architecture
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