This project focused on the enhancement of a previous battery-less wireless traffic flow sensor so as to enable it to provide weigh-in-motion (WIM) measurements and provide enhanced telemetry distance. The sensor consists of a 6-feet-long device which is embedded in a slot in the road flush with the pavement. As a vehicle travels over the
sensor, vibrations are induced in the sensor. Using piezoelectric elements, energy is harvested from the vibrations and used to power the electronics in the sensor for signal measurements and wireless transmission.
The sensor’s performance was evaluated by embedding it in a slot in concrete pavement and driving various vehicles of known weight over it at a number of different speeds on different days. The sensor was found to meet
the specification of 500 feet telemetry distance. It was able to provide WIM measurements with an accuracy of better than ±15% in the absence of vehicle suspension vibrations.
However, much of the WIM data during the latter period of sensor testing was obtained in the presence of significant suspension vibrations. The project also evaluated the use of 4 consecutive WIM sensors in the road to remove the influence of suspension vibrations.
University of Minnesota Center for Transportation Studies
Intelligent Transportation Systems Institute
Pruden, Sean; Vijayaraghavan, Krishna; Rajamani, Rajesh.
Enhancement and Field Test Evaluation of New Battery-Less Wireless Traffic Sensors.
Center for Transportation Studies.
Retrieved from the University of Minnesota Digital Conservancy,
Content distributed via the University of Minnesota's Digital Conservancy may be subject to additional license and use restrictions applied by the depositor.