atmos:535:projects:lufft_intelligent_road_sensor
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atmos:535:projects:lufft_intelligent_road_sensor [2008/10/07 19:43] – wikiadmin | atmos:535:projects:lufft_intelligent_road_sensor [2020/01/29 17:25] (current) – external edit 127.0.0.1 | ||
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+ | ====== Intelligent Road Sensor ====== | ||
+ | * Manafacturer: | ||
+ | * Model Number: 21 | ||
+ | {{atmos: | ||
+ | |||
+ | --- // [Jennifer Green] // | ||
+ | |||
+ | ===== Description ===== | ||
+ | |||
+ | |||
+ | ==== Measurement Physics ==== | ||
+ | |||
+ | ====Summary of Measurements==== | ||
+ | The Lufft Intelligent Road Sensor measures surface pavement temperature, | ||
+ | |||
+ | ====Temperature==== | ||
+ | * Temperature sensor is located inside the dent of the Intelligent Road Sensor in the central electrode. | ||
+ | * Temparature sensor is a thermistor in which the resistance of the thermistor is a function of temperature. | ||
+ | * This sensor measures the surface pavement temperature, | ||
+ | * If the two optional temperature probes are added they can measure subsurface temperatures. | ||
+ | * Measured in degrees Celcius | ||
+ | |||
+ | =====Salt Concentration===== | ||
+ | * Measured with the two electrodes inside the dent of the Intelligent Road Sensor. | ||
+ | * As more current can pass between the two electrodes the higher the salt concentration is on the road. | ||
+ | * Uses electrodes designed specifically for salt measurement | ||
+ | * Measurements are in % salt concentration | ||
+ | * Only salt is measured, but other chemicals can be requested to be integrated in by manufacturer | ||
+ | |||
+ | =====Freezing Temperature===== | ||
+ | * If salt concentration is known (from measurements) then the freezing temperature can be calculated. | ||
+ | {{atmos: | ||
+ | |||
+ | =====Water Film Height===== | ||
+ | * Water film height is measured with a CW-radar (continious-wave radar) located inside the Intelligent Road Sensor | ||
+ | * A continious wave radar is a radar who continously sends out a wave and recieves a signal back from it. This is unlike pulse radars that are commonly used in meteorology. | ||
+ | * A CW-radar normally can not measure distance but a frequency shift can be used to determine distance. | ||
+ | * Water film height can be measured up to 4mm. | ||
+ | * However, water film height is recorded as an index from zero to 250 in which 150 represents no water film on the Intelligent Road Sensor, readings closer to zero mean more water is on the sensor and readings closer to 250 mean more ice is on the sensor. | ||
+ | |||
+ | ====Multi-Frequency==== | ||
+ | |||
+ | * Is the two metal circles on the surface of the Intelligent Road Sensor. | ||
+ | * It is an impedance sensor | ||
+ | |||
+ | ====Road Conditions==== | ||
+ | |||
+ | * Not directly measured but instead based off of the readings from the Intelligent Road Sensor | ||
+ | * Processed inside the sensor | ||
+ | * Road can be in the following conditions and the numbers next to them represent the code recorded onto the data logger for road condition | ||
+ | *Dry (0) | ||
+ | *Damp (1) | ||
+ | *Wet (2) | ||
+ | *Ice (3) | ||
+ | *Frost / Snow (4) | ||
+ | *Residual Salt (5) | ||
+ | *Freezing Wet (6) | ||
+ | *Undefined / Can not be determined (98,99) | ||
+ | * A nominated temperature “TPOS” is used (default value 2ºC) | ||
+ | * If above road can be “Dry”, “Residual Salt”, “Damp”, and “Wet” | ||
+ | * If below the road can also be “Freezing Wetness”, “Frost / Snow” and “Ice” | ||
+ | |||
+ | ==-= Performance Characteristics =-== | ||
+ | |||
+ | {{atmos: | ||
+ | |||
+ | {{atmos: | ||
+ | |||
+ | ==== Field projects ==== | ||
+ | |||
+ | The Intelligent Road Sensor is currently being used at the Surface Transportation Weather Research Center' | ||
+ | |||
+ | {{atmos: | ||
+ | This is a picture of the field site where the Intelligent Road Sensor is circled in red | ||
+ | |||
+ | {{atmos: | ||
+ | This is a close up picture of the Intelligent Road Sensor at the field site. The red line shows where the communication cable is that leads back to a data logger. | ||
+ | |||
+ | ==== Reference ==== | ||
+ | * http:// | ||
+ | * http:// | ||
+ | * http:// | ||
+ | * http:// | ||
+ | * http:// | ||
+ | * http:// | ||
+ | |||
+ | ===== Calibration ===== | ||
+ | |||
+ | The Intelligent Road Sensor comes with a certificate stating the calibration test results. | ||
+ | |||
+ | {{atmos: | ||
+ | |||
+ | ==== Method ==== | ||
+ | |||
+ | The Aurora project has run several different calibration tests on various pavement sensors, uncluding the Intelligent Road Sensor. | ||
+ | |||
+ | * Cold day with and without direct solar impact | ||
+ | * Cold night with and without strong radiational cooling | ||
+ | * Warm pavement with snowfall | ||
+ | * Cold pavement with rainfall | ||
+ | * Iced pavement with rainfall \\ | ||
+ | |||
+ | Also some lab tests were done with checking the salt concetration measurements. | ||
+ | |||
+ | * NaCl on a cold day with and without direct solar impact | ||
+ | * NaCl on warm pavement with snowfall | ||
+ | * NaCl on cold pavement with rainfall | ||
+ | * NaCl on iced pavement with rainfall \\ | ||
+ | |||
+ | The results from these tests can be found at: http:// | ||
+ | |||
+ | |||
+ | ==== Calibration Checked ==== | ||
+ | |||
+ | It is recomended by the manufacturer to do a calibration tests once every year. If the unit needs to be removed it needs to be done on a non-preciptation day with dry pavement. | ||
+ | |||
+ | ===== Deployment / Usage ===== | ||
+ | |||
+ | ==== Exposure Requirements ==== | ||
+ | |||
+ | The Intelligent Road Sensor was designed to be pavement for long periods of time. This sensor was designed to be outdoors and in extreme temperatures. | ||
+ | |||
+ | ==== Communication ==== | ||
+ | |||
+ | Communication to and from the Intelligent road sensor is done through the communication cable which is connected to a data logger. | ||
+ | |||
+ | ==== Power ==== | ||
+ | |||
+ | The Lufft runs off of a 12V power supply provided by the data logger. | ||
+ | |||
+ | ==== Installation ==== | ||
+ | |||
+ | It is important to note that it is very important to keep the sensor flush with the road and to not have the sensor go above the road surface. | ||
+ | |||
+ | {{atmos: | ||
+ | This is a diagram of the installed Intelligent Road Sensor \\ \\ | ||
+ | |||
+ | The main thing to point out with installation is that once the sensor is in the pavement it is pretty permanent. | ||
+ | |||
+ | ==== Who Could Use Intelligent Road Sensor Data ==== | ||
+ | |||
+ | The main group of people who could use data collected from the Intelligent Road Sensor is the Department of Transportation. | ||
+ | |||
+ | Also data from the Intelligent Road Sensor can be put into models that help predict road conditions and make plowing forescasts / plans as part of the model. | ||
+ | |||
+ | One idea that Lufft has for the Intelligent Road Sensor data is a LED sensor-to-sign that changes as the conditions on the road change. | ||
+ | |||
+ | {{atmos: | ||
+ | This is a picture of the sensor-to-sign LED sign. | ||
+ | |||
+ | ===== Data ===== | ||
+ | |||
+ | * A live feed of data collected from the Intelligent Road Sensor can be found at the following link | ||
+ | * Data from the Intelligent Road Sensor is being stored and archived for the purposes of research at STWRC and collected every 2 minutes as well as a 30 minute average. \\ \\ | ||
+ | |||
+ | {{atmos: | ||
+ | This is data pulled from the data logger. \\ \\ | ||
+ | |||
+ | {{atmos: | ||
+ | This is a graph of surface temperature data taken on January 7, 2006 from 12:02am to 11: |