Piezoelectric Sensors for Weigh-In-Motion Systems

Piezoelectric Sensors for Weigh-In-Motion Systems

Author: J. Iaquinta

Publisher:

Published: 2004

Total Pages: 8

ISBN-13:

DOWNLOAD EBOOK

Experimental campaigns conducted on the theme of weigh-in-motion exhibited an unexpected scattering of the weight measurements. In spite of several attempts, no argument was found to satisfactorily explain the dispersal, in particular for the sites implementing piezoelectric sensors. After tackling this problem numerically in a previous study, the present investigation aims at understanding experimentally the behavior of such systems within the material in which they are embedded in the road. A field campaign utilizing an instrumented truck confirmed a loss of sensitivity at the ends of the sensor. This result was also corroborated by laboratory testing on a servohydraulic jack. It is shown that the location of a load over the sensor affects its response, and that only a small part of the traffic lane is saved from edge effects. The major mission of this work is to make users of weigh-in-motion systems based upon piezoelectric sensors aware of this phenomenon so that they can take actions to recognize and compensate for the potential measurement errors associated with using this type of sensor.


Evaluation of Thermocoax Piezoelectric Weigh-in-Motion Sensors

Evaluation of Thermocoax Piezoelectric Weigh-in-Motion Sensors

Author: Highway Innovative Technology Evaluation Center (U.S.)

Publisher: ASCE Publications

Published: 2001-01-01

Total Pages: 80

ISBN-13: 9780784475072

DOWNLOAD EBOOK

Prepared by the Highway Innovative Technology Evaluation Center (HITEC), a CERF Innovation Center. This report describes a program of installation, testing, and evaluation designed to determine the capabilities and limitations of Thermocoax's weigh-in-motion sensor.


Investigation of Environmental Impacts on Piezoelectric Weigh-in-motion Sensing System

Investigation of Environmental Impacts on Piezoelectric Weigh-in-motion Sensing System

Author: Shahram Hashemi Vaziri

Publisher:

Published: 2011

Total Pages: 173

ISBN-13:

DOWNLOAD EBOOK

Transportation by trucks plays a major role in North America's economy. The growth of this industry will increase the loads on existing roads and highways and raises the possibility of overloaded vehicles, which causes significant damage to the pavement and consequently will reduce the lifespan of the roads. Weigh-in-motion (WIM) systems technology helps to address the challenge of overloaded vehicles. This technology provides traffic monitoring, collects data for pavement research and design, and improves the capacity of static weigh station operations. However, there is still a lack of knowledge about the behaviour of WIM sensors installed in different environments, which affects reliable and precise data gathering. More knowledge is required on proper installation procedures, pavement design for WIM systems, choice of sensor type for location, and calibration processes. This research is intended to explore the behaviour of WIM piezoelectric sensors under different loads and environmental conditions. Specifically, the effects of air and pavement temperature, and weight and speed of trucks are examined with respect to the estimation accuracy of WIM sensors. To accomplish this, three WIM systems composed of different piezoelectric transducers were installed at the CPATT test site at the Waste Management facility of the Region of Waterloo in 2007, and two WIM systems were installed between exits 238 and 250 on Highway 401 eastbound near Woodstock, Ontario. It was concluded that the output of the polymer piezoelectric sensor is influenced by temperature and weight factors but not by normally observed vehicle speed differences. While temperature can be compensated for, not enough information has been gathered yet does the same for weight factor. It should be noted that very low speeds (e.g.


Evaluation of Weigh-in-motion Systems

Evaluation of Weigh-in-motion Systems

Author: Benjamin H. Cottrell

Publisher:

Published: 1992

Total Pages: 106

ISBN-13:

DOWNLOAD EBOOK

The objective of this research was to evaluate low cost weigh-in-motion systems. The three systems evaluated were (1) a capacitance weigh mat system, (2) a bridge weighing system, and (3) a piezoelectric cable sensor system. All three systems have a two-lane capability. An evaluation was made of (1) the quality of the data, (2) the performance of the equipment, (3) the applications of the equipment and its ease ofuse, and (4) the format of the data and its usefulness. Although objective data were used when possible, the majority of the evaluation is subjective. The quality of the data from each of the three systems is about the same. The piezoelectric cable system provides slightly lower quality data than the other two systems. The equipment of the capacitance weigh mat performed well; that of the bridge system was adequate; and there was concern about the durability of the piezoelectric cable system. Because of the tradeoffs between the capacitance weigh mat system and the bridge system, it is difficult to rank them. The piezoelectric cable system's sensors are permanently installed; therefore, it is not as portable as the other two systems. With regard to the format of the data and its usefulness (which are dependent mostly on the software and not the sensors), the capacitance weigh mat system is flexible and provides individual truck records in two formats, the bridge system provides the most comprehensive tables, and the piezoelectric cable system is limited and depends on other software to generate additional tables. Suggestions are made about how to use the systems and how to improve their performance.


WITS 2020

WITS 2020

Author: Saad Bennani

Publisher: Springer Nature

Published: 2021-07-21

Total Pages: 1139

ISBN-13: 9813368934

DOWNLOAD EBOOK

This book presents peer-reviewed articles from the 6th International Conference on Wireless Technologies, Embedded and Intelligent Systems (WITS 2020), held at Fez, Morocco. It presents original research results, new ideas and practical lessons learnt that touch on all aspects of wireless technologies, embedded and intelligent systems. WITS is an international conference that serves researchers, scholars, professionals, students and academicians looking to foster both working relationships and gain access to the latest research results. Topics covered include Telecoms & Wireless Networking Electronics & Multimedia Embedded & Intelligent Systems Renewable Energies.


Laboratory and Field Evaluation of Piezoelectric Weigh-in-Motion Sensors

Laboratory and Field Evaluation of Piezoelectric Weigh-in-Motion Sensors

Author: AT. Papagiannakis

Publisher:

Published: 2001

Total Pages: 9

ISBN-13:

DOWNLOAD EBOOK

This paper presents the results of the laboratory and field evaluation of the piezoelectric weigh-in-motion (WIM) sensors of two manufacturers, namely Vibracoax (VC) and Measurements Specialties Incorporated (MSI). The laboratory evaluation involved fatigue testing of two sensor types for each manufacturer, one factory-encapsulated and the other bare. The fatigue testing involved three contact stresses as well as dry and wet conditions. Significant sensor fatigue was experienced only under wet conditions. The field evaluation of these sensors was carried in both asphalt concrete (AC) and Portland concrete (PC) installations. The facilities at Nevada's WesTrack and at a CalTrans Heavy Vehicle Simulator site were used, respectively. All sensors exhibited high raw signal precision at any given time. Raw signal amplitude seemed to depend on temperature for the sensors installed in the AC pavement. For increasing pavement temperature, the raw signal amplitude of the VC sensors decreased, while that of the MSI sensors increased. The signal-to-noise ratio of the raw signal increased with increasing temperature for the sensors installed in the AC pavement. WIM load measurement precision and sensitivity to temperature varied between sensors. The poor load precision of some of the sensors was attributed to the load calculation algorithm in the WIM data acquisition system, rather than to sensor malfunctioning. During the period of the field tests, no consistent changes in WIM axle load measurements were observed that could be attributed to piezoelectric sensor fatigue.


Equipment for Collecting Traffic Load Data

Equipment for Collecting Traffic Load Data

Author: Mark E. Hallenbeck

Publisher: Transportation Research Board

Published: 2004

Total Pages: 68

ISBN-13: 0309087880

DOWNLOAD EBOOK

Introduction -- Types of equipment -- Technology descriptions -- A process for selecting equipment -- Best practices for equipment use -- Abbreviations used without definitions in TRB publications.


Development in Piezoelectric Weigh-in-motion Systems

Development in Piezoelectric Weigh-in-motion Systems

Author:

Publisher:

Published: 1987

Total Pages: 23

ISBN-13:

DOWNLOAD EBOOK

With the current trend towards deregulation in the north american trucking environment, there will be an increasing demand to monitor the ongoing changes in vehicle weights and dimensions. there is now considerable emphasis on producing an accurate weigh in motion (wim) scale that will be relatively inexpensive and yet able to withstand the harsh extremes of the canadian climate. developments in piezoelectric weigh in motion (pwim) systems show a good deal of promise in this regard. this paper reviews the technological developments of pwim, explores parameters affecting the accuracy and longevity of these systems, and shows how pwim can be used: 1) to enhance the data collection efforts of agencies concerned with road safety and pavement deterioration, and 2) to provide for the data collection needs of special programs such as the strategic highway research program (shrp) in the united states and c-shrp in canada. for the covering abstract of the conference see irrd 807058.