scholarly journals Improving the Accuracy of Estimates of Indoor Distance Moved Using Deep Learning-Based Movement Status Recognition

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 346
Author(s):  
Zhenjie Ma ◽  
Wenjun Zhang ◽  
Ke Shi
Keyword(s):  
Deep Learning ◽  
Indoor Positioning ◽  
Ultra Wideband ◽  
Indoor Environments ◽  
Job Allocation ◽  
The Real ◽  
Positioning Errors ◽  
Wireless Signal ◽  
Movement Distance ◽  
Status Recognition

As a result of the development of wireless indoor positioning techniques such as WiFi, Bluetooth, and Ultra-wideband (UWB), the positioning traces of moving people or objects in indoor environments can be tracked and recorded, and the distances moved can be estimated from these data traces. These estimates are very useful in many applications such as workload statistics and optimized job allocation in the field of logistics. However, due to the uncertainties of the wireless signal and corresponding positioning errors, accurately estimating movement distance still faces challenges. To address this issue, this paper proposes a movement status recognition-based distance estimating method to improve the accuracy. We divide the positioning traces into segments and use an encoder–decoder deep learning-based model to determine the motion status of each segment. Then, the distances of these segments are calculated by different distance estimating methods based on their movement statuses. The experiments on the real positioning traces demonstrate the proposed method can precisely identify the movement status and significantly improve the distance estimating accuracy.

scholarly journals Integrated IMU with Faster R-CNN Aided Visual Measurements from IP Cameras for Indoor Positioning

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3134 ◽  
Author(s):  
Lin Zhang ◽  
Taoyun Zhou ◽  
Baowang Lian
Keyword(s):  
Indoor Positioning ◽  
Ultra Wideband ◽  
Measurement Unit ◽  
Indoor Environments ◽  
Inertial Measurement ◽  
Positioning Errors ◽  
Measurement Units ◽  
Stationary Obstacles ◽  
Indoor Scenarios ◽  
Visual Measurements

Considering the radio-based indoor positioning system pertaining to signal degradation due to the environmental factors, and rising popularity of IP (Internet Protocol) cameras in cities, a novel fusion of inertial measurement units (IMUs) with external IP cameras to determine the positions of moving users in indoor environments is presented. This approach uses a fine-tuned Faster R-CNN (Region Convolutional Neural Network) to detect users in images captured by cameras, and acquires visual measurements including ranges and angles of users with respect to the cameras based on the proposed monocular vision relatively measuring (MVRM) method. The results are determined by integrating the positions predicted by each user’s inertial measurement unit (IMU) and visual measurements using an EKF (Extended Kalman Filter). The results experimentally show that the ranging accuracy is affected by both the detected bounding box’s by Faster R-CNN height errors and diverse measuring distances, however, the heading accuracy is solely interfered with bounding box’s horizontal biases. The indoor obstacles including stationary obstacles and a pedestrian in our tests more significantly decrease the accuracy of ranging than that of heading, and the effect of a pedestrian on the heading errors is greater than stationary obstacles on that. We implemented a positioning test for a single user and an external camera in five indoor scenarios to evaluate the performance. The robust fused IMU/MVRM solution significantly decreases the positioning errors and shows better performance in dense multipath scenarios compared with the pure MVRM solution and ultra-wideband (UWB) solution.

scholarly journals Deep-Learning-Based Wi-Fi Indoor Positioning System Using Continuous CSI of Trajectories

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5776
Author(s):  
Zhongfeng Zhang ◽  
Minjae Lee ◽  
Seungwon Choi
Keyword(s):  
Deep Learning ◽  
Short Term Memory ◽  
Software Radio ◽  
Multipath Fading ◽  
Indoor Positioning ◽  
Training Dataset ◽  
Positioning System ◽  
Indoor Environments ◽  
Generative Adversarial Network ◽  
Indoor Positioning System

In a Wi-Fi indoor positioning system (IPS), the performance of the IPS depends on the channel state information (CSI), which is often limited due to the multipath fading effect, especially in indoor environments involving multiple non-line-of-sight propagation paths. In this paper, we propose a novel IPS utilizing trajectory CSI observed from predetermined trajectories instead of the CSI collected at each stationary location; thus, the proposed method enables all the CSI along each route to be continuously encountered in the observation. Further, by using a generative adversarial network (GAN), which helps enlarge the training dataset, the cost of trajectory CSI collection can be significantly reduced. To fully exploit the trajectory CSI’s spatial and temporal information, the proposed IPS employs a deep learning network of a one-dimensional convolutional neural network–long short-term memory (1DCNN-LSTM). The proposed IPS was hardware-implemented, where digital signal processors and a universal software radio peripheral were used as a modem and radio frequency transceiver, respectively, for both access point and mobile device of Wi-Fi. We verified that the proposed IPS based on the trajectory CSI far outperforms the state-of-the-art IPS based on the CSI collected from stationary locations through extensive experimental tests and computer simulations.

Deep Learning for Ultra-Wideband Indoor Positioning

2021 ◽  
Author(s):  
Yi-Min Lu ◽  
Jang-Ping Sheu ◽  
Yung-Ching Kuo
Keyword(s):  
Deep Learning ◽  
Indoor Positioning ◽  
Ultra Wideband

scholarly journals Unsupervised Indoor Positioning System Based on Environmental Signatures

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 327
Author(s):  
Pan Feng ◽  
Danyang Qin ◽  
Min Zhao ◽  
Ruolin Guo ◽  
Teklu Berhane
Keyword(s):  
Dead Reckoning ◽  
Indoor Positioning ◽  
Convergence Time ◽  
Positioning System ◽  
Indoor Environments ◽  
Test Results ◽  
Positioning Errors ◽  
Localization And Mapping ◽  
Indoor Positioning System ◽  
Unconventional Method

Mobile sensors are widely used in indoor positioning in recent years, but most methods require cumbersome calibration for precise positioning results, thus the paper proposes a new unsupervised indoor positioning (UIP) without cumbersome calibration. UIP takes advantage of environment features in indoor environments, as some indoor locations have their signatures. UIP considers these signatures as the landmarks, and combines dead reckoning with them in a simultaneous localization and mapping (SLAM) frame to reduce positioning errors and convergence time. The test results prove that the system can achieve accurate indoor positioning, which highlights its prospect as an unconventional method of indoor positioning.

scholarly journals Analysis and Improvement of Indoor Positioning Accuracy for UWB Sensors

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5731
Author(s):  
Leehter Yao ◽  
Lei Yao ◽  
Yeong-Wei Wu
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Indoor Positioning ◽  
Mobile Node ◽  
Ultra Wideband ◽  
Positioning Accuracy ◽  
3 Dimensional ◽  
Positioning Errors ◽  
3D Positioning ◽  
2D And 3D

Ultra-wideband (UWB) sensors have been widely applied to indoor positioning. The indoor positioning of UWB sensors usually refers to the positioning of the mobile node that interacts with the anchors through radio for calculating the distance between the mobile node and each of the surrounding anchors. The positioning accuracy of the mobile node is affected by the installation positions of surrounding anchors. A mathematical model was proposed in this paper to respectively analyze the mobile node’s 2-dimensional (2D) and 3-dimensional (3D) positioning errors. The factors influencing the mobile node’s positioning errors were explored through the mathematical models. The best installation positions of surrounding anchors were obtained based on the mathematical models. The mobile node’s 2D and 3D positioning errors were reduced based on the anchor positions derived from the mathematical model. Both computer simulations and practical experiments were implemented to justify the results obtained in the mathematical models.

scholarly journals An Approach to Robust INS/UWB Integrated Positioning for Autonomous Indoor Mobile Robots

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 950 ◽  
Author(s):  
Jianfeng Liu ◽  
Jiexin Pu ◽  
Lifan Sun ◽  
Zishu He
Keyword(s):  
Mobile Robots ◽  
Difficult Problem ◽  
Ultra Wideband ◽  
Indoor Environments ◽  
Navigation Systems ◽  
Problem Of Time ◽  
Positioning Errors ◽  
Multipath Effects ◽  
Effective System ◽  
Adaptive Adjustment

The key to successful positioning of autonomous mobile robots in complicated indoor environments lies in the strong anti-interference of the positioning system and accurate measurements from sensors. Inertial navigation systems (INS) are widely used for indoor mobile robots because they are not susceptible to external interferences and work properly, but the positioning errors may be accumulated over time. Thus ultra wideband (UWB) is usually adopted to compensate the accumulated errors due to its high ranging precision. Unfortunately, UWB is easily affected by the multipath effects and non-line-of-sight (NLOS) factor in complex indoor environments, which may degrade the positioning performance. To solve above problems, this paper proposes an effective system framework of INS/UWB integrated positioning for autonomous indoor mobile robots, in which our modeling approach is simple to implement and a Sage–Husa fuzzy adaptive filter (SHFAF) is proposed. Due to the favorable property (i.e., self-adaptive adjustment) of SHFAF, the difficult problem of time-varying noise in complex indoor environments is considered and solved explicitly. Moreover, outliers can be detected and corrected by the proposed sliding window estimation with fading coefficients. This facilitates the positioning performance improvement for indoor mobile robots. The benefits of what we propose are illustrated by not only simulations but more importantly experimental results.

scholarly journals A Method for Improving UWB Indoor Positioning

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Zhanjun Hao ◽  
Beibei Li ◽  
Xiaochao Dang
Keyword(s):  
Estimation Method ◽  
Pulse Amplitude ◽  
Relative Displacement ◽  
Indoor Positioning ◽  
Base Stations ◽  
Ultra Wideband ◽  
Signal Interference ◽  
Positioning Errors ◽  
Wireless Environment ◽  
The Time Domain

The existing positioning methods that use received signal strength indication (RSSI) and channel state information (CSI) may suffer from multipath and shadowing in a complex wireless environment, which can result in more positioning errors. This paper proposes a method for accurate multilabel positioning in the non-line-of-sight (NLOS) environment. First, the position is roughly estimated using the orthogonal variable spreading factor (OVSF-TH) algorithm, which can automatically match the signal interference. The ultra-wideband (UWB) spectral density and pulse amplitude in the time domain are used to determine the direction of the label and enhance estimation of the mobile label direction. Then, the location of the tag is obtained by triangulation, and a coordinate-based coordinate estimation method is proposed to calculate the relative displacement of multiple tags to determine the label position. Finally, by setting up a real experimental environment, the influence of the number of base stations on the accuracy and the performance of the localization method under different circumstances are analyzed. The theoretical analysis and experimental results show that the method is simple to deploy, inexpensive, and very accurate in terms of positioning, having a clearly effective indoor positioning accuracy. Compared with other existing positioning methods, this method can achieve more accurate positioning. Moreover, it has important theoretical and practical applicability because of the reliability and accuracy of indoor positioning in an NLOS environment.

scholarly journals Improved Indoor Positioning by Means of Occupancy Grid Maps Automatically Generated from OSM Indoor Data

2021 ◽  
Vol 10 (4) ◽  
pp. 216
Author(s):  
Thomas Graichen ◽  
Julia Richter ◽  
Rebecca Schmidt ◽  
Ulrich Heinkel
Keyword(s):  
Automatic Generation ◽  
Indoor Positioning ◽  
Ultra Wideband ◽  
Sensor Data ◽  
Indoor Environments ◽  
Occupancy Grid ◽  
Occupancy Probability ◽  
Occupancy Grid Maps ◽  
Map Data ◽  
Positioning Algorithm

In recent years, there is a growing interest in indoor positioning due to the increasing amount of applications that employ position data. Current approaches determining the location of objects in indoor environments are facing problems with the accuracy of the sensor data used for positioning. A solution to compensate inaccurate and unreliable sensor data is to include further information about the objects to be positioned and about the environment into the positioning algorithm. For this purpose, occupancy grid maps (OGMs) can be used to correct such noisy data by modelling the occupancy probability of objects being at a certain location in a specific environment. In that way, improbable sensor measurements can be corrected. Previous approaches, however, have focussed only on OGM generation for outdoor environments or require manual steps. There remains need for research examining the automatic generation of OGMs from detailed indoor map data. Therefore, our study proposes an algorithm for automated OGM generation using crowd-sourced OpenStreetMap indoor data. Subsequently, we propose an algorithm to improve positioning results by means of the generated OGM data. In our study, we used positioning data from an Ultra-wideband (UWB) system. Our experiments with nine different building map datasets showed that the proposed method provides reliable OGM outputs. Furthermore, taking one of these generated OGMs as an example, we demonstrated that integrating OGMs in the positioning algorithm increases the positioning accuracy. Consequently, the proposed algorithms now enable the integration of environmental information into positioning algorithms to finally increase the accuracy of indoor positioning applications.

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.

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