scholarly journals Pointing Sensors and Sun Tracking Techniques

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
D. Fontani ◽  
P. Sansoni ◽  
F. Francini ◽  
D. Jafrancesco ◽  
L. Mercatelli ◽  
...  
Keyword(s):  
Optical System ◽  
Tracking System ◽  
Field Tests ◽  
The Sun ◽  
System Configuration ◽  
The Core ◽  
Passive Tracking ◽  
Working Principle ◽  
Tracking Device ◽  
Guiding System

Every optical system for sunlight concentration requires following the sun in its movement. The sun tracking method is essentially chosen on the base of collection geometry and optical system configuration. A simple, useful, and original technique to realise sun tracking is proposed. It is based on a double guiding system using two complementary procedures. A passive tracking device performs a preliminary collector orientation. Then an active tracking system realises its fine positioning and adjustments exploiting an optical pointing sensor. The core of this active tracking device is the sun finder. Pointing sensors for fibre-coupled, CPV (Concentrating Photo voltaic), and linear collectors are presented, illustrating in detail the working principle and practical use. All sensors were optically characterised in laboratory, under controlled and reproducible conditions. Some field tests completed the experimentation evaluating the sensors performance in outdoor working conditions.

scholarly journals Autonomous Tracking by an Adaptable Scaled KCF Algorithm

2021 ◽  
Vol 11 (1) ◽  
pp. 48-54
Author(s):  
Din-Chang Tseng ◽  
◽  
Chien-Hung Chen ◽  
Yi-Ming Chen
Keyword(s):  
Computer Vision ◽  
Tracking System ◽  
Passive Tracking ◽  
Feature Based ◽  
Tracking Device ◽  
Tracking Devices

A multicopter is equipped by a passive tracking device to follow a specified target. However, if want to track a non-controlled target, the passive tracking device is failed. We propose a vision-based tracking system for multicopters, used computer vision method to track any target without additional tracking devices. In this study, propose scale candidate graphs and scale tables to improve KCF. There are also stable results when the scale changes. The proposed an adaptable scaled KCF algorithm, when the KCF tracking failed, a feature-based matching detector is used to re-detect the target. Several experiments on various scene based on the proposed approach were conducted and evaluated. Stable tracking results were obtain to show the feasibility of the proposed system.

scholarly journals A Passive Tracking System Based on Geometric Constraints in Adaptive Wireless Sensor Networks

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3276 ◽  
Author(s):  
Biao Zhou ◽  
Deockhyeon Ahn ◽  
Jungpyo Lee ◽  
Chao Sun ◽  
Sabbir Ahmed ◽  
...  
Keyword(s):  
Power Consumption ◽  
Tracking System ◽  
Spatial Diversity ◽  
Geometric Constraints ◽  
Wireless Sensor ◽  
Tracking Accuracy ◽  
Passive Tracking ◽  
Save Energy ◽  
Tracking Device ◽  
Device Free

Target tracking technologies in wireless sensor network (WSNs) environments fall into two categories: active and passive schemes. Unlike with the active positioning schemes, in which the targets are required to hold cooperative devices, the research on passive tracking, i.e., tracking device-free targets, has recently showed promise. In the WSN, device-free targets can be tracked by sensing radio frequency tomography (RFT) on the line-of-sight links (LOSLs). In this paper, we propose a passive tracking scheme exploiting both adaptive-networking LOSL webs and geometric constraint methodology for tracking single targets, as well as multiple targets. Regarding fundamental knowledge, we firstly explore the spatial diversity technique for RFT detection in realistic situations. Then, we analyze the power consumption of the WSN and propose an adaptive networking scheme for the purpose of energy conservation. Instead of maintaining a fixed LOSL density, the proposed scheme can adaptively adjust the networking level to save energy while guaranteeing tracking accuracy. The effectiveness of the proposed scheme is evaluated with computer simulations. According to the results, it is observed that the proposed scheme can sufficiently reduce power consumption, while providing qualified tracking performance.

A Novel Photovoltaic Module With Cell Strands That Track the Sun

2017 ◽  
Author(s):  
Bill Diong ◽  
Wesley Carlsen ◽  
Brian Avit ◽  
Kevin McFall ◽  
Scott Tippens
Keyword(s):  
Tracking System ◽  
Photovoltaic Cells ◽  
Photovoltaic Module ◽  
The Sun ◽  
Solar Panels ◽  
Initial Cost ◽  
Daily Energy ◽  
Passive Tracking ◽  
Tracking Ability ◽  
Roof Panel

The goal of a recent study was to design, and determine the effectiveness of, a fixed-tilt solar panel module that contains strands of photovoltaic cells, which are rotated by a very small motor to track the sun. The motivation was that such a configuration enjoys the advantage of increased energy collection over static solar panels due to sun tracking ability, while it mitigates some key difficulties associated with stabilizing and rotating bulky panels as current active and passive tracking systems need to do. Most critically, such a module allows the benefits of sun tracking to be reaped by sloped roof panel installations, which at present almost always consist of fixed-tilt solar panels rather than rotating tracking panels. The study’s result is an active tracking system design in a fixed-tilt module configuration that generated over 10% more daily energy typically, during the test period, compared to a static panel, thus substantially offsetting its added complexity and higher initial cost.

Automatic Two Axes Sun-Tracking System Applied to Photovoltaic System for LED Street Light

2010 ◽  
Vol 43 ◽  
pp. 17-20 ◽  
Author(s):  
Quan Wang ◽  
Jin Zhang ◽  
Ran Hu ◽  
Ying Shao
Keyword(s):  
Tracking System ◽  
Photovoltaic System ◽  
The Sun ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Efficient System ◽  
The Earth ◽  
Tracking Device ◽  
Fixed Panel ◽  
Worm Drive

This paper presents an electromechanical, two axes sun tracking system based on single chip microcomputer (MCU). According to the path of the sun in the space, the earth coordinate system is chosen to design the tracking device. The whole device consists of one worm-drive and one gear-drive, which is operated by two step motors. The photodiodes are used as photoelectric sensors to detect the pointing of the sun. Eight photodiodes are installed in the diameter hole of the hemispherical surface. The comparative signals produced by the diodes array are performed to judge the orientation of the solar panel. The circuit of the control system based on MCU is demonstrated. The comparative signals may be amplified, A/D converted. After a series of signal processing, the signals are sent to the MCU which will produce the pulse to control the speed and steering of step motors. The sun tracking system is an efficient system for solar energy collection. It has been proved that the sun tracking systems can collect up to 50% more energy than what a fixed panel system collects.

scholarly journals Enlarging the Eyebox of Maxwellian Displays with a Customized Liquid Crystal Dammann Grating

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 195
Author(s):  
Ziqian He ◽  
Kun Yin ◽  
Kuan-Hsu Fan-Chiang ◽  
Shin-Tson Wu
Keyword(s):  
Liquid Crystal ◽  
Optical System ◽  
Proof Of Concept ◽  
System Configuration ◽  
Distributed Energy ◽  
Good Efficiency ◽  
High Brightness ◽  
Full Color ◽  
Crystal Polymer ◽  
Maxwellian View

The Maxwellian view offers a promising approach to overcome the vergence-accommodation conflict in near-eye displays, however, its pinhole-like imaging naturally limits the eyebox size. Here, a liquid crystal polymer-based Dammann grating with evenly distributed energy among different diffraction orders is developed to enlarge the eyebox of Maxwellian view displays via pupil replication. In the experiment, a 3-by-3 Dammann grating is designed and fabricated, which exhibits good efficiency and high brightness uniformity. We further construct a proof-of-concept Maxwellian view display breadboard by inserting the Dammann grating into the optical system. The prototype successfully demonstrates the enlarged eyebox and full-color operation. Our work provides a promising route of eyebox expansion in Maxwellian view displays while maintaining full-color operation, simple system configuration, compactness, and lightweight.

Microcontroller Based Single Axis Intelligent Control Sun Tracker for Parabolic Trough Collectors

2012 ◽  
Vol 562-564 ◽  
pp. 1772-1775
Author(s):  
Shakeel Akram ◽  
Farhan Hameed Malik ◽  
Rui Jin Liao ◽  
Bin Liu ◽  
Tariq Nazir
Keyword(s):  
Energy Efficiency ◽  
Embedded System ◽  
Alternative Energy ◽  
Power Plants ◽  
Tracking System ◽  
Appropriate Technology ◽  
Working Fluid ◽  
The Sun ◽  
Solar Collectors ◽  
Parabolic Trough

Due to the complex design and high costs of production, solar thermal systems have fallen behind in the world of alternative energy systems. Different mechanisms are applied to increase the efficiency of the solar collectors and to reduce the cost. Solar tracking system is the most appropriate technology to increase the efficiency of solar collectors as well as solar power plants by tracking the sun timely. In order to maximize the efficiency of collectors, one needs to keep the reflecting surface of parabolic trough collectors perpendicular to the sun rays. For this purpose microcontroller based real time sun tracker is designed which is controlled by an intelligent algorithm using shadow technique. The aim of the research project is to test the solar-to-thermal energy efficiency by tracking parabolic trough collector (PTC). The energy efficiency is determined by measuring the temperature rise of working fluid as it flows through the receiver of the collector when it is properly focused. The design tracker is also simulated to check its accuracy. The main purpose to design this embedded system is to increase the efficiency and reliability of solar plants by reducing size, complexity and cost of product.

scholarly journals In Vitro and In Vivo Assessment of a New Workflow for the Acquisition of Mandibular Kinematics Based on Portable Tracking System with Passive Optical Reflective Markers

2021 ◽  
Vol 11 (9) ◽  
pp. 3947
Author(s):  
Marco Farronato ◽  
Gianluca M. Tartaglia ◽  
Cinzia Maspero ◽  
Luigi M. Gallo ◽  
Vera Colombo
Keyword(s):  
Measurement Error ◽  
Tracking System ◽  
Intraclass Correlation ◽  
Optical Tracking ◽  
Optical Tracking System ◽  
Rater Reliability ◽  
Tracking Device ◽  
Mandibular Kinematics

Clinical use of portable optical tracking system in dentistry could improve the analysis of mandibular movements for diagnostic and therapeutic purposes. A new workflow for the acquisition of mandibular kinematics was developed. Reproducibility of measurements was tested in vitro and intra- and inter-rater repeatability were assessed in vivo in healthy volunteers. Prescribed repeated movements (n = 10) in three perpendicular directions of the tracking-device coordinate system were performed. Measurement error and coefficient of variation (CV) among repetitions were determined. Mandibular kinematics of maximum opening, left and right laterality, protrusion and retrusion of five healthy subjects were recorded in separate sessions by three different operators. Obtained records were blindly examined by three observers. Intraclass correlation coefficient (ICC) was calculated to estimate inter-rater and intra-rater reliability. Maximum in vitro measurement error was 0.54 mm and CV = 0.02. Overall, excellent intra-rater reliability (ICC > 0.90) for each variable, general excellent intra-rater reliability (ICC = 1.00) for all variables, and good reliability (ICC > 0.75) for inter-rater tests were obtained. A lower score was obtained for retrusion with “moderate reliability” (ICC = 0.557) in the inter-rater tests. Excellent repeatability and reliability in optical tracking of primary movements were observed using the tested portable tracking device and the developed workflow.

scholarly journals Magnetic Tracking: A Novel Method of Assessing Anterior Cruciate Ligament Deficiency

2006 ◽  
Vol 88 (1) ◽  
pp. 16-17 ◽  
Author(s):  
RK Kundra ◽  
JD Moorehead ◽  
N Barton-Hanson ◽  
SC Montgomery
Keyword(s):  
Anterior Cruciate Ligament ◽  
Tracking System ◽  
Cruciate Ligament ◽  
Magnetic Tracking ◽  
Lachman Test ◽  
Acl Deficiency ◽  
Anterior Tibial ◽  
Anterior Cruciate ◽  
Tracking Device ◽  
Acl Deficient

INTRODUCTION The Lachman test is commonly performed as part of the routine assessment of patients with suspected anterior cruciate ligament (ACL) deficiency. A major drawback is its reliance on the clinician's subjective judgement of movement. The aim of this study was to quantify Lachman movement using a magnetic tracking device thereby providing a more accurate objective measure of movement. PATIENTS AND METHODS Ten patients aged 21–51 years were assessed as having unilateral ACL deficiency with conventional clinical tests. These patients were then re-assessed using a Polhemus Fastrak™ magnetic tracking device. RESULTS The mean anterior tibial displacement was 5.6 mm (SD = 2.5) for the normal knees and 10.2 mm (SD = 4.2) for the ACL-deficient knees. This gave an 82% increase in anterior tibial displacement for the ACL deficient knees. This was shown to be highly significant with P = 0.005. CONCLUSIONS The magnetic tracking system offers an objective quantification of displacements during the Lachman test. It is convenient, non-invasive and comfortable for the patient and is, therefore, ideally suited for use as an investigative tool.

scholarly journals Sensor-Based Safety Performance Assessment of Individual Construction Workers

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3897 ◽  
Author(s):  
JeeWoong Park ◽  
Yong K. Cho ◽  
Ali Khodabandelu
Keyword(s):  
Risk Model ◽  
Tracking System ◽  
Field Tests ◽  
Safety Performance ◽  
Worker Safety ◽  
Well Test ◽  
Construction Sites ◽  
Monitoring Method ◽  
Safety Issues ◽  
Automated Method

Over the last decade, researchers have explored various technologies and methodologies to enhance worker safety at construction sites. The use of advanced sensing technologies mainly has focused on detecting and warning about safety issues by directly relying on the detection capabilities of these technologies. Until now, very little research has explored methods to quantitatively assess individual workers’ safety performance. For this, this study uses a tracking system to collect and use individuals’ location data in the proposed safety framework. A computational and analytical procedure/model was developed to quantify the safety performance of individual workers beyond detection and warning. The framework defines parameters for zone-based safety risks and establishes a zone-based safety risk model to quantify potential risks to workers. To demonstrate the model of safety analysis, the study conducted field tests at different construction sites, using various interaction scenarios. Probabilistic evaluation showed a slight underestimation and overestimation in certain cases; however, the model represented the overall safety performance of a subject quite well. Test results showed clear evidence of the model’s ability to capture safety conditions of workers in pre-identified hazard zones. The developed approach presents a way to provide visualized and quantified information as a form of safety index, which has not been available in the industry. In addition, such an automated method may present a suitable safety monitoring method that can eliminate human deployment that is expensive, error-prone, and time-consuming.

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