Sensor Performance in Measuring Vehicle Length

2013 ◽  
Vol 2339 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Erik Minge ◽  
Scott Petersen
Keyword(s):  
Field Testing ◽  
The United States ◽  
Vehicle Classification ◽  
Vehicle Speed ◽  
Detector Performance ◽  
Sensor Performance ◽  
Loop Detectors ◽  
Small Magnetic Field ◽  
Loop Detector ◽  
Detection Technologies

Although most vehicle classification conducted in the United States is axle based, some applications could be supplemented or replaced by length-based data. Common length-based methods, including loop detectors and several types of nonloop sensors (both side-fire and in-road sensors), are more widespread and can be less expensive. The most frequently deployed data collection method is by loop detector, and most dual-loop installations can report vehicle length. This paper examines field and laboratory tests of loop detectors and nonloop sensors for their performance in determining vehicle length and vehicle speed. Field testing was conducted at four locations in Minnesota and South Dakota. Ten commercially available sensors were evaluated. The testing results indicated that across a variety of detection technologies, the loop detectors and nonloop sensors generally reported comparable length and speed data. The research also examined various loop configurations and found that 6- x 6-ft loops performed similarly to 6- x 8-ft loops, although 6- x 6-ft quadrupole loops performed poorly for vehicles with high beds because of the loops’ relatively small magnetic field. Loop detector performance was found not to degrade with the variety of lead-in wire lengths that were tested. Laboratory testing conducted with a loop simulator confirmed the field testing and found that loop detector data are generally repeatable.

Development of a System for Collecting Loop-Detector Event Data for Individual Vehicles

2003 ◽  
Vol 1855 (1) ◽  
pp. 168-175 ◽  
Author(s):  
Xiaoping Zhang ◽  
Yinhai Wang ◽  
Nancy L. Nihan ◽  
Mark E. Hallenbeck
Keyword(s):  
Real Time ◽  
Sampling Rate ◽  
Field Application ◽  
Normal Operation ◽  
Vehicle Speed ◽  
Event Data ◽  
Loop Detectors ◽  
Loop Detector ◽  
High Sampling Rate ◽  
Loop Detection

Typical freeway inductive loop detection systems, under normal operation, aggregate individual loop-detector actuations sampled at 60 Hz into 20-s or 30-s averages of velocity, flow, and lane-occupancy measurements. While such aggregations are appropriate for serving as inputs to control system algorithms, and they save disk space for archiving loop data, a large amount of useful data regarding individual vehicles is lost. For single-loop detectors, the lost information includes individual vehicle arrival, departure, and presence times. For speed traps, the lost information also includes the calculated individual vehicle speed and length. Yet this information about individual vehicles is desirable to transportation researchers and planners. The unavailability of this information makes in-depth investigation of detector errors difficult or even impossible. A system for collecting detector event data is proposed. This system can sample loop actuations with sampling rates of 60 Hz or higher and then save, process, and present the collected event data in real time without interfering with the detector controller’s normal operation. A stand-alone Windows program was developed for performing real-time high-frequency loop event data collection. A system reliability test and field application indicate that the system can collect realtime detector event data at a high sampling rate (60 Hz or higher). Additionally, this system makes real-time loop data quality evaluation, loop malfunction identification, and loop error correction feasible.

Railway track irregularity and curvature estimation using doppler LIDAR fiber optics

2016 ◽  
Vol 232 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Masood Taheri Andani ◽  
Andrew Peterson ◽  
Josh Munoz ◽  
Mehdi Ahmadian
Keyword(s):  
Fiber Optics ◽  
Field Testing ◽  
Railway Track ◽  
Vehicle Speed ◽  
Doppler Lidar ◽  
Close Match ◽  
Track Geometry ◽  
Lidar Measurements ◽  
Curvature Estimation ◽  
Geometry Measurement

The application of Doppler-based LIght Detection and Ranging (LIDAR) technology for determining track curvature and lateral irregularities, including alignment and gage variation, are investigated. The proposed method uses track measurements by two low-elevation, slightly tilted LIDAR sensors nominally pointed at the rail gage face on each track. The Doppler LIDAR lenses are installed with a slight forward angle to measure track speed in both longitudinal and lateral directions. The lateral speed measurements are processed for assessing the track gage and alignment variations, using a method that is based on the frequency bandwidth dissimilarities between the vehicle speed and track geometry irregularity. Using the results from an extensive series of tests with a body-mounted Doppler LIDAR system on-board a track geometry measurement railcar, the study indicates a close match between the LIDAR measurements and those made with existing sensors on-board the railcar. The field testing conducted during this study indicates that LIDAR sensors could provide a reliable, non-contact track monitoring instrument for field use in various weather and track conditions, potentially in a semi-autonomous or autonomous manner.

Estimation of Truck Traffic Volume from Single Loop Detectors with Lane-to-Lane Speed Correlation

2003 ◽  
Vol 1856 (1) ◽  
pp. 106-117 ◽  
Author(s):  
Jaimyoung Kwon ◽  
Pravin Varaiya ◽  
Alexander Skabardonis
Keyword(s):  
Real Time ◽  
Time Estimation ◽  
The United States ◽  
Truck Traffic ◽  
Single Loop ◽  
Loop Detectors ◽  
Time Estimates ◽  
Surveillance Technology ◽  
Traffic Volumes ◽  
Urban Freeway

An algorithm for real-time estimation of truck traffic in multilane freeways was proposed. The algorithm used data from single loop detectors—the most widely installed surveillance technology for urban freeways in the United States. The algorithm worked for those freeway locations that have a truck-free lane and exhibit high lane-to-lane speed correlation. These conditions are met by most urban freeway locations. The algorithm produced real-time estimates of the truck traffic volumes at the location. It also can be used to produce alternative estimates of the mean effective vehicle length, which can improve speed estimates from single loop detector data. The algorithm was tested with real freeway data and produced estimates of truck traffic volumes with only 5.7% error. It also captured the daily patterns of truck traffic and mean effective vehicle length. Applied to loop data on Interstate 710 near Long Beach, California, during the dockworkers’ lockout October 1 to 9, 2002, the algorithm found a 32% reduction in five-axle truck volume.

Real-Time Traffic Measurement from Single Loop Inductive Signatures

2002 ◽  
Vol 1804 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Seri Oh ◽  
Stephen G. Ritchie ◽  
Cheol Oh
Keyword(s):  
Real Time ◽  
The United States ◽  
Traffic Data ◽  
Traffic Surveillance ◽  
Vehicle Class ◽  
Traffic Measurement ◽  
Single Loop ◽  
Loop Detectors ◽  
Real Time Traffic ◽  
Traffic Data Collection

Accurate traffic data acquisition is essential for effective traffic surveillance, which is the backbone of advanced transportation management and information systems (ATMIS). Inductive loop detectors (ILDs) are still widely used for traffic data collection in the United States and many other countries. Three fundamental traffic parameters—speed, volume, and occupancy—are obtainable via single or double (speed-trap) ILDs. Real-time knowledge of such traffic parameters typically is required for use in ATMIS from a single loop detector station, which is the most commonly used. However, vehicle speeds cannot be obtained directly. Hence, the ability to estimate vehicle speeds accurately from single loop detectors is of considerable interest. In addition, operating agencies report that conventional loop detectors are unable to achieve volume count accuracies of more than 90% to 95%. The improved derivation of fundamental real-time traffic parameters, such as speed, volume, occupancy, and vehicle class, from single loop detectors and inductive signatures is demonstrated.

Thermal Performance of Unvented Attics in Hot-Dry Climates: Results from Building America

2004 ◽  
Vol 126 (2) ◽  
pp. 732-737 ◽  
Author(s):  
Robert Hendron ◽  
Sara Farrar-Nagy ◽  
Ren Anderson ◽  
Paul Reeves ◽  
Ed Hancock
Keyword(s):  
Design Feature ◽  
Field Testing ◽  
The United States ◽  
National Renewable Energy Laboratory ◽  
Advantages And Disadvantages ◽  
Heating And Cooling ◽  
Energy Trade ◽  
Insulation Thickness ◽  
Dry Climates ◽  
Building Loss

As unvented attics have become a more common design feature implemented by Building America partners in hot-dry climates of the United States, more attention has been focused on how this approach affects heating and cooling energy consumption. By eliminating the ridge and eave vents that circulate outside air through the attic in most new houses and by moving the insulation from the attic floor to the underside of the roof, an unvented attic becomes a semiconditioned space, creating a more benign environment for space conditioning ducts. An energy trade-off is made, however, because the additional surface area (and perhaps reduced insulation thickness) increases the building loss coefficient. Other advantages and disadvantages, unrelated to energy, must also be considered. This paper addresses the energy-related effects of unvented attics in hot-dry climates based on field testing and analysis conducted by the National Renewable Energy Laboratory.

Materials Interface Interactions Test (MIIT); in-Situ Testing of Simulated Hlw Forms in Salt- Performance of Srs Simulated Waste Glass After up to 5 Years of Burial at the Waste Isolation Pilot Plant (WIPP)

1991 ◽  
Vol 257 ◽  
Author(s):  
G.G. Wicks ◽  
A.R. Lodding ◽  
P.B. Macedo ◽  
D.E. Clark
Keyword(s):  
United States ◽  
Pilot Plant ◽  
Field Tests ◽  
Field Testing ◽  
The United States ◽  
Waste Glass ◽  
Department Of Energy ◽  
High Level Waste ◽  
Waste Isolation Pilot Plant ◽  
High Level

ABSTRACTThe first field tests conducted in the United States involving burial of simulated high-level waste [HLW] forms and package components, were started in July of 1986. The program, called the Materials Interface Interactions Test or MIIT, is the largest cooperative field-testing venture in the international waste management community. Included in the study are over 900 waste form samples comprising 15 different systems supplied by 7 countries. Also included are approximately 300 potential canister or overpack metal samples along with more than 500 geologic and backfill specimens. There are almost 2000 relevant interactions that characterize this effort which is being conducted in the bedded salt site at the Waste Isolation Pilot Plant (WIPP), near Carlsbad, New Mexico. The MIIT program represents a joint endeavor managed by Sandia National Laboratories in Albuquerque, N.M., and Savannah River Laboratory in Aiken, S.C. and sponsored by the U.S. Department of Energy. Also involved in MIIT are participants from various laboratories and universities in France, Germany, Belgium, Canada, Japan, Sweden, the United Kingdom, and the United States. In July of 1991, the experimental portion of the 5-yr. MIIT program was completed. Although only about 5% of all MIIT samples have been assessed thus far, there are already interesting findings that have emerged. The present paper will discuss results obtained for SRS 165/TDS waste glass after burial of 6 mo., 1 yr. and 2 yrs., along with initial analyses of 5 yr. samples.

scholarly journals Deep data science to prevent and treat growth faltering in Maya children

2016 ◽  
Vol 70 (6) ◽  
pp. 679-680 ◽  
Author(s):  
M I Varela-Silva ◽  
◽  
B Bogin ◽  
J A G Sobral ◽  
F Dickinson ◽  
...  
Keyword(s):  
Data Science ◽  
Somatic Growth ◽  
Field Testing ◽  
The United States ◽  
Child Growth ◽  
Southern Mexico ◽  
Cultural Variables ◽  
Growth Faltering ◽  
Maya People ◽  
Height For Age

Abstract The Maya people are descended from the indigenous inhabitants of southern Mexico, Guatemala and adjacent regions of Central America. In Guatemala, 50% of infants and children are stunted (very low height-for-age), and some rural Maya regions have >70% children stunted. A large, longitudinal, intergenerational database was created to (1) provide deep data to prevent and treat somatic growth faltering and impaired neurocognitive development, (2) detect key dependencies and predictive relations between highly complex, time-varying, and interacting biological and cultural variables and (3) identify targeted multifactorial intervention strategies for field testing and validation. Contributions to this database included data from the Universidad del Valle de Guatemala Longitudinal Study of Child and Adolescent Development, child growth and intergenerational studies among the Maya in Mexico and studies about Maya migrants in the United States.

Thermal Performance of Unvented Attics in Hot-Dry Climates: Results From Building America

Solar Energy ◽  
2003 ◽  
Author(s):  
Robert Hendron ◽  
Sara Farrar-Nagy ◽  
Ren Anderson ◽  
Paul Reeves ◽  
Ed Hancock
Keyword(s):  
Design Feature ◽  
Field Testing ◽  
The United States ◽  
National Renewable Energy Laboratory ◽  
Advantages And Disadvantages ◽  
Heating And Cooling ◽  
Energy Trade ◽  
Insulation Thickness ◽  
Dry Climates ◽  
Building Loss

As unvented attics have become a more common design feature implemented by Building America partners in hot-dry climates of the United States, more attention has been focused on how this approach affects heating and cooling energy consumption. By eliminating the ridge and eave vents that circulate outside air through the attic in most new houses and by moving the insulation from the attic floor to the underside of the roof, an unvented attic becomes a semiconditioned space, creating a more benign environment for space conditioning ducts. An energy trade-off is made, however, because the additional surface area (and perhaps reduced insulation thickness) increases the building loss coefficient. Other advantages and disadvantages, unrelated to energy, must also be considered. This paper addresses the energy-related effects of unvented attics in hot-dry climates based on field testing and analysis conducted by the National Renewable Energy Laboratory.

Field Testing Plan for Positive Train Control Enforcement in Passenger Terminals

2020 ◽  
Author(s):  
Zhipeng Zhang ◽  
Xiang Liu ◽  
Keith Holt
Keyword(s):  
United States ◽  
Field Tests ◽  
Field Testing ◽  
The United States ◽  
Test Sequence ◽  
Benefit Cost Analysis ◽  
Stub End ◽  
Speed Enforcement ◽  
Passenger Terminals ◽  
Operational Impact

Abstract In the United States, a train moving onto a terminating track at a passenger terminal relies on the train engineer’s operation. Currently, there are no mechanisms installed at the U.S. passenger terminals that are able to automatically stop a train before reaching the end of the track if an engineer fails to do so. The engineer’s actions determine whether the train will safely stop before the end of the terminating track. Thus, incapacitated or inattentive engineer operation would result in end-of-track collisions, such as the New Jersey Transit train accident at Hoboken Terminal in 2016. Currently, PTC enforcement is not required in passenger terminals. In an ongoing project tasked by the Federal Railroad Administration, we study the cost-effectiveness and operational impact of possible PTC enforcement to prevent end-of-track collisions. Specifically, a Concept of Operations (ConOps) was developed to outline the proposed plans to implement two of the most widely used PTC types, namely the Advanced Civil Speed Enforcement System (ACSES) and Interoperable Electronic Train Management System (I-ETMS). This paper describes in-field testing of the ConOps in ACSES-type terminal. In the planned field test, a train equipped with one locomotive and at least one passenger coach would be tested on platform tracks in a selected passenger terminal. These are three major testing components, which are test equipment, test track, and recorded information for each test sequence. Firstly, in terms of equipment, a traffic cone will be placed on the track to simulate a bumping post. In ACSES system, two sets of transponders are programmed to require a positive stop within a specified distance and mounted to the cross ties at specified positions. Secondly, a yard track will be used to test the feasibility of this exercise at the beginning. Upon successfully completing the test multiple times, a series of tests will also be made on the studied platform track. Thirdly, each test run should record the distance from the head end of the test train and the traffic cone for each test run. In addition, ACSES system should also record the information on the ACSES display as it passes the first and second transponder set, respectively. Overall, the field tests presented in this paper, along with previous work in benefit-cost analysis and operational impact assessment, can contribute to an assessment of the proposed PTC implementation at stub-end terminals in the United States in order to effectively and efficiently prevent end-of-track collisions.

Field Verification of Moving Load Model for Pavement Response

1996 ◽  
Vol 1540 (1) ◽  
pp. 125-131 ◽  
Author(s):  
Raj Siddharthan ◽  
Jian Yao ◽  
Peter E. Sebaaly
Keyword(s):  
Moving Load ◽  
Field Tests ◽  
Field Testing ◽  
Material Behavior ◽  
Vehicle Speed ◽  
Strain Response ◽  
State University ◽  
Load Model ◽  
Pavement Response ◽  
The Difference

A validation study undertaken to verify the predictive capability of a recently developed moving load model to predict pavement response is described. The full-scale field-measured responses of longitudinal strain at the bottom of the asphalt concrete (AC) layer were used in the verification. The field testing program, in which the strain responses induced by a semitrailer truck were measured as a function of vehicle speed, was carried out at the Pennsylvania State University test track. The material behavior of the AC layer, which was assumed to be viscoelastic, was deduced from the laboratory behavior of the AC and from the backcalculated AC modulus from falling-weight deflectometer data. The unbound material layer properties were assumed to be elastic. The moving load model reproduced many important general observations made from the field tests, such as the existence of a complex interaction in the case of a tandem axle configuration and the strong influence of vehicle speed on the strain response. Good agreement exists between the predictions made by the model for the strain response for single and tandem axle configurations under different loading and vehicle speeds and those measured in the field. The difference is less than 14 percent, thus verifying the applicability of the moving load model to predict pavement response.

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