scholarly journals Virtual reality for animal navigation with camera-based optical flow tracking

2019 ◽  
Author(s):  
Ivan Vishniakou ◽  
Paul G. Plöger ◽  
Johannes D. Seelig
Keyword(s):  
Virtual Reality ◽  
Optical Flow ◽  
Motion Tracking ◽  
Tracking System ◽  
Processing Parameters ◽  
Calibration Data ◽  
Tracking Accuracy ◽  
Ball Size ◽  
Ball Tracking ◽  
Ball Motion

AbstractBackgroundVirtual reality combined with spherical treadmills is used across species for studying neural circuits underlying navigation.New MethodWe developed an optical flow-based method for tracking treadmil ball motion in real-time using a single high-resolution camera.ResultsTracking accuracy and timing were determined using calibration data. Ball tracking was performed at 500 Hz and integrated with an open source game engine for virtual reality projection. The projection was updated at 120 Hz with a latency with respect to ball motion of 30 ± 8 ms.Comparison with Existing Method(s)Optical flow based tracking of treadmill motion is typically achieved using optical mice. The camera-based optical flow tracking system developed here is based on off-the-shelf components and offers control over the image acquisition and processing parameters. This results in flexibility with respect to tracking conditions – such as ball surface texture, lighting conditions, or ball size – as well as camera alignment and calibration.ConclusionsA fast system for rotational ball motion tracking suitable for virtual reality animal behavior across different scales was developed and characterized.

scholarly journals Unsupervised Learning in RSS-Based DFLT Using an EM Algorithm

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5549
Author(s):  
Ossi Kaltiokallio ◽  
Roland Hostettler ◽  
Hüseyin Yiğitler ◽  
Mikko Valkama
Keyword(s):  
Em Algorithm ◽  
Expectation Maximization ◽  
Tracking System ◽  
Model Parameters ◽  
Calibration Data ◽  
Tracking Accuracy ◽  
Time Period ◽  
The Em Algorithm ◽  
Device Free ◽  
Localization And Tracking

Received signal strength (RSS) changes of static wireless nodes can be used for device-free localization and tracking (DFLT). Most RSS-based DFLT systems require access to calibration data, either RSS measurements from a time period when the area was not occupied by people, or measurements while a person stands in known locations. Such calibration periods can be very expensive in terms of time and effort, making system deployment and maintenance challenging. This paper develops an Expectation-Maximization (EM) algorithm based on Gaussian smoothing for estimating the unknown RSS model parameters, liberating the system from supervised training and calibration periods. To fully use the EM algorithm’s potential, a novel localization-and-tracking system is presented to estimate a target’s arbitrary trajectory. To demonstrate the effectiveness of the proposed approach, it is shown that: (i) the system requires no calibration period; (ii) the EM algorithm improves the accuracy of existing DFLT methods; (iii) it is computationally very efficient; and (iv) the system outperforms a state-of-the-art adaptive DFLT system in terms of tracking accuracy.

A Study of Tracking System Using Multiple Emitter Towers

2013 ◽  
Vol 694-697 ◽  
pp. 927-935 ◽  
Author(s):  
Yi Sun ◽  
Tao Ma ◽  
Chia Yung Han ◽  
Joseph Ross ◽  
William Wee
Keyword(s):  
Coordinate Transformation ◽  
Motion Tracking ◽  
Tracking System ◽  
Transformation Method ◽  
Tracking Accuracy ◽  
Working Space ◽  
Frontal Part ◽  
Motion Tracking System ◽  
Coordinate Transformation Method

This paper presents a simple and accurate coordinate transformation method for extending the tracking space of the Intersense IS-900 spatial and motion tracking system using multiple pre-configured emitter towers to form the emitter constellation, but without resorting to the use of a surveyor machine. The proposed approach uses the differences of positional coordinate readings from each emitter tower among a set of commonly viewed spatial points to calculate the parameters needed to define the coordinate transformation. By applying this method, the tracking accuracy using the entire emitter constellation can be achieved by less than 0.5 inches error in most of the working space, and as low as 0.2 inches error in the frontal part of the working space.

scholarly journals Cricket umpire assistance and ball tracking system using a single smartphone camera

2017 ◽  
Author(s):  
Udit Arora ◽  
Sohit Verma ◽  
Sarthak Sahni ◽  
Tushar Sharma
Keyword(s):  
Machine Learning ◽  
Open Source ◽  
Motion Tracking ◽  
Tracking System ◽  
Contour Detection ◽  
Machine Learning Algorithms ◽  
Machine Learning Techniques ◽  
Support Vector ◽  
Ball Tracking ◽  
Histogram Of Gradients

Several ball tracking algorithms have been reported in literature. However, most of them use high-quality video and multiple cameras, and the emphasis has been on coordinating the cameras or visualizing the tracking results. This paper aims to develop a system for assisting the umpire in the sport of Cricket in making decisions like detection of no-balls, wide-balls, leg before wicket and bouncers, with the help of a single smartphone camera. It involves the implementation of Computer Vision algorithms for object detection and motion tracking, as well as the integration of machine learning algorithms to optimize the results. Techniques like Histogram of Gradients (HOG) and Support Vector Machine (SVM) are used for object classification and recognition. Frame subtraction, minimum enclosing circle, and contour detection algorithms are optimized and used for the detection of a cricket ball. These algorithms are applied using the Open Source Python Library - OpenCV. Machine Learning techniques - Linear and Quadratic Regression are used to track and predict the motion of the ball. It also involves the use of open source Python library VPython for the visual representation of the results. The paper describes the design and structure for the approach undertaken in the system for analyzing and visualizing off-air low-quality cricket videos.

scholarly journals Identification of most influential factors in a Virtual Reality tracking system using hybrid method

ACTA IMEKO ◽  
2014 ◽  
Vol 2 (2) ◽  
pp. 20
Author(s):  
Fabien Ezedine ◽  
Jean-Marc Linares ◽  
Wan Mansor Wan Muhamad ◽  
Jean-Michel Sprauel
Keyword(s):  
Virtual Reality ◽  
Hybrid Method ◽  
Tracking System ◽  
Influential Factors ◽  
Tracking Accuracy ◽  
Camera System ◽  
The Monte Carlo Method ◽  
Total Knee ◽  
Knee Arthroplasty Surgery ◽  
Arthroplasty Surgery

This paper studies the factors that influence the accuracy of Virtual Reality (VR) systems, in particular for applications in a Cave Automatic Virtual Environment (CAVE). The CAVE can be used to train surgeon students. For this purpose, an application for a total knee arthroplasty surgery is investigated. To meet the requirements for a high quality training, the accuracy of the tracking system in the CAVE has to be improved. First, a complete model of the tracking system is created based on the extrinsic and intrinsic parameters of the eight-camera system. With this mode l, the uncertainty of the tracking system is determined for one location in the CAVE. Next, a hybrid method, comprising the Monte Carlo Method and Design Of Experiment, is used to find the most important factors influencing the tracking accuracy in the CAVE.

scholarly journals Evaluation of real time motion tracking accuracy of customised IMU sensor for application in a mobile badminton virtual reality training system

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Zahari Taha ◽  
Mohd Yashim Wong ◽  
Hwa Jen Yap ◽  
Amirul Abdullah ◽  
Wee Kian Yeo
Keyword(s):  
Virtual Reality ◽  
Real Time ◽  
Motion Tracking ◽  
Training System ◽  
Microsoft Kinect ◽  
Measurement Unit ◽  
Tracking Accuracy ◽  
Improve Performance ◽  
Motion Data ◽  
Time Motion

Immersion is one of the most important aspects in ensuring the applicability of Virtual Reality systems to training regimes aiming to improve performance. To ensure that this key aspect is met, the registration of motion between the real world and virtual environment must be made as accurate and as low latency as possible. Thus, an in-house developed Inertial Measurement Unit (IMU) system is developed for use in tracking the movement of the player’s racquet. This IMU tracks 6 DOF motion data and transmits it to the mobile training system for processing. Physically, the custom motion is built into the shape of a racquet grip to give a more natural sensation when swinging the racquet. In addition to that, an adaptive filter framework is also established to cope with different racquet movements automatically, enabling real-time 6 DOF tracking by balancing the jitter and latency. Experiments are performed to compare the efficacy of our approach with other conventional tracking methods such as the using Microsoft Kinect. The results obtained demonstrated noticeable accuracy and lower latency when compared with the aforementioned methods.

scholarly journals Optimization and Simulation of Virtual Experiment System of Human Sports Science Based on VR

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Gaixin Li
Keyword(s):  
Virtual Reality ◽  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Human Motion ◽  
Flow Diagram ◽  
Virtual Experiment ◽  
Experiment System ◽  
Sports Science ◽  
Motion Tracking System

Virtual reality technology is an emerging technology developed on the basis of information technology. It is widely used in military, medical, mining, entertainment, and other fields. Therefore, many countries have been vigorously conducting research in recent years. As one of the important components of the virtual reality system, the three-dimensional human motion tracking system is of great significance to the research of practical virtual reality systems. It introduces the measurement principle of the spatial three-dimensional coordinate dynamic measurement device and discusses in detail the ultrasonic transmission, reception, amplification, filtering, comparison, shaping circuit, and single-chip interface circuit. This paper introduces the working principle and characteristics of the virtual experiment system and gives the structure diagram, hardware schematic diagram, and software flow diagram of the system. We mainly study the method of tracking human motion by measuring the three-dimensional coordinates of the space point, which lays a good foundation for the research of the actual three-dimensional motion tracking system. At the same time, the three-dimensional human body modeling is discussed, and the interactive movement policy of the human arm is briefly introduced. It has a certain effect on the actual virtual reality human-computer interaction system.

scholarly journals Optoelectronic tracking system for shooting simulator - tests in a virtual reality application

2020 ◽  
Vol 12 (2) ◽  
pp. 61
Author(s):  
Marcin Maciejewski ◽  
Marek Piszczek ◽  
Mateusz Pomianek ◽  
Norbert Pałka
Keyword(s):  
Virtual Reality ◽  
Motion Tracking ◽  
Tracking System ◽  
Low Cost ◽  
Test Results ◽  
Virtual Reality System ◽  
Training Simulator ◽  
Present Test ◽  
Accuracy And Precision ◽  
Tracking Device

We present test results of an authorial tracking device developed in the SteamVR system, optimized for use in a missile launcher shooting simulator. Data for analysis was collected using the virtual reality training application, with the launcher set on a stable tripod and held by a trainee who executed two scenarios with static and movable targets. The analysis of experimental data confirms that the SteamVR system together with the developed tracker can be successfully implemented in the virtual shooting simulator. Full Text: PDF ReferencesD. Bogatinov, P. Lameski, V. Trajkovik, K.M. Trendova, "Firearms training simulator based on low cost motion tracking sensor", Multimed. Tools Appl. 76(1) (2017) CrossRef D.C. Niehorster, L. Li, M. Lappe, "The Accuracy and Precision of Position and Orientation Tracking in the HTC Vive Virtual Reality System for Scientific Research", Iperception. 8(3) (2017) CrossRef A. Yates, J. Selan, POSITIONAL TRACKING SYSTEMS AND METHODS. US20160131761A1, (2016) DirectLink P. Caserman, A. Garcia-Agundez, R. Konrad, S. Göbel, R. Steinmetz, Virtual Real. 23(2) (2019) 155-68. CrossRef

Impacts of respiratory phase shifts on motion‐tracking accuracy of the CyberKnife Synchrony™ Respiratory Tracking System

2019 ◽  
Vol 46 (9) ◽  
pp. 3757-3766 ◽  
Author(s):  
Yuichi Akino ◽  
Hiroya Shiomi ◽  
Iori Sumida ◽  
Fumiaki Isohashi ◽  
Yuji Seo ◽  
...  
Keyword(s):  
Motion Tracking ◽  
Tracking System ◽  
Phase Shifts ◽  
Tracking Accuracy ◽  
Respiratory Phase ◽  
Respiratory Tracking

scholarly journals Virtual Reality Technologies and Universal 3D Reconstruction Interface Development

2020 ◽  
pp. 192-205
Author(s):  
Maxim Mironenko ◽  
Viktor Chertopolokhov ◽  
Margarita Belousova
Keyword(s):  
Virtual Reality ◽  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Urban Landscapes ◽  
Mathematical Methods ◽  
Historical Sources ◽  
Reconstruction Process ◽  
Software And Hardware ◽  
Three Dimensional Models

The article summarizes the results of a two-year study of the issues related to the virtual reality and augmented reality technologies use to virtually reconstruct Moscow Bely Gorod in the 16th-18th centuries. The authors describe mathematical methods, software and hardware which grant access to the historical reconstruction of historical urban landscapes. An important feature of the reconstruction is the source verification module which was used to construct three-dimensional models of the landscape, buildings and the general scenery. The article names the basic principles which the verification module and its interface are based on and considers some optimum problems solved when constructing the interface. The project uses a hybrid motion tracking system as a combination of optical and inertial data. The archival sources used in the reconstruction process are presented in the virtual environment by means of a 3D graphical user interface for the virtual reality. The information displayed is generated from the database of historical sources which includes information about the urban development and individual buildings of Bely Gorod, their parts, location, purpose, owners and construction date. The database contains both text and graphic historical sources. The results obtained also include new algorithms, software and hardware systems as well as the experiment results. 

scholarly journals Optimization of Interface Elements Order in Virtual Reality (Virtual Reconstruction of Bely Gorod Historical Relief)

2020 ◽  
pp. 81-93 ◽  
Author(s):  
Stepan Lemak ◽  
Viktor Chertopolokhov ◽  
Anna Kruchinina ◽  
Margarita Belousova ◽  
Leonid Borodkin ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Motion Tracking ◽  
Tracking System ◽  
Virtual Space ◽  
Interface Element ◽  
Eye Tracker ◽  
Historical Sources ◽  
Interface Elements ◽  
Virtual Reconstruction ◽  
Space Modeling

The article sets a problem focusing on how to optimize the order of 3D user interface for virtual reconstruction of Moscow historical center landscape in the 16th-18th centuries. To work with the interface a virtual reality headset, a motion tracking system and an eye-tracker were integrated. Spatial representation of the historical reconstruction is accompanied by a specialized interface that allows one to access the source database. The authors introduce a criterion that provides for estimating the optimum order of interface elements in the virtual space. The problem is handled in case there are unknown factors such as the size of user's hands, deviations in the position of an interactive object and restrictions related to the disposition of interface elements. The article sets the general problem and solves some internal problems related to the construction of acceptable multiple dispositions of interface elements and the modeling of eyesight movement from one interface element to another. The article is the first to suggest an algorithm to numerically optimize the interface in 3D virtual space modeling the relief and historical buildings in the center of Moscow. It provides for user’s movement and gives access to historical sources which are the basis for virtual reconstruction of the heritage understudy.

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