Lufft in sääsensorit maa ilman teillä Ely-keskus Kouvola Tiesääpäivät 3-4.6.2013 ilkka.lilja@iloy.fi
Measuring road conditions : why? Security Road accidents kill about 1,2 million people in the world every year. It makes it one of the biggest mortality causes. In many cases, weather conditions played a role in the accident. Rain, fog, snow, or sunshine are as many factors which can affect the security of the driver. Traffic management Having a precise picture of the road state is also a valuable asset when it comes to traffic management. By analysing weather-related preliminary phases of possible traffic jams, it is often possible to avoid them. Cost optimization Ever thought about the economical en environmental cost of salt spreading? An estimated 1.59 million tons of road salt on average are applied on public roadways in Germany each year...
Security Dangers related to weather conditions 1. Rain In wet weather, stopping distances will be at least double those required for stopping on dry roads. This is because your tyres have less grip on the road. Moreover, the phenomenon of aquaplanning (or hydroplanning) is a real danger for the drivers. It occurs when a tyre's tread pattern is unable to disperse sufficient water from the road surface. Levels of traction (and therefore control) decrease as the size of the contact patch decreases.
Security Dangers related to weather conditions 1. Rain The rain and spray from vehicles may make it difficult to see and be seen, thus making its danger even bigger. Of course below a certain temperature, rain will fast change into ice... Remember : A wet road is twice as slippery as a dry road
Security Dangers related to weather conditions 2. Ice & snow Winter conditions are even more critical for the driver. Not only there is a risk of icing, but the efficiency of the tyre will also decrease. The gum of the tyre goes harder, and therefore, the grip diminishes. Remember : A snowbound road is twice as slippery as a wet road An icy road is twice as slippery as a snowbound road
Security Dangers related to weather conditions 2. Ice & snow cont During winter, road services are on alert. A good knowledge of the road conditions will allow them to prevent any risk for the drivers. Spreading some salt over the road will be commonly used as an effective solution to avoid the forming of ice, however : Below - 21 C, water saturated with salt would freeze anyway An overload of salt would worsen the situation (over saturation) Preventing the drivers keeps being an effective solution
Security Dangers and damages related to weather conditions 3. Hail During summer severe hail events could occur. Besides the potential of extensive damage, the impact on traffic is also considerably high. Hail is often limited in time and local diffusion and is very difficult to be forecasted.
Security Dangers related to weather conditions 4. Fog The award for most dangerous weather condition goes to fog. If the fog suddenly clears don't relax think you're out of danger. Fog is usually quite patchy going from a light mist to a thick cloud in a matter of meters. You could turn a corner only to find yourself in a dense blanket of fog.
Security Dangers related to weather conditions 5. Wind The high-sided vehicles are most affected by windy weather, but strong gusts can also blow a car or a motorcyclist. This can happen on open stretches of road exposed to strong crosswinds, or when passing bridges or gaps in hedges. Some places are more exposed to some strong winds and therefore have to be controlled in priority. But the main risk caused by wind is the fact that it can lay down the trees or other elements surrounding the road.
Economies and Savings Potential savings: with optimal maintenance decision support: Saving or reduction of observation tours Saving of needless Treatment Tours Saving of deicing chemical by means of adequate Dosage Saving of Stand-By duties Optimizing of treatment recommendations and plans Example of the distribution of typical winter maintenance expenses Deicing material vehicle expenses Fahrzeug- /Gerätekosten 22% Taumittel/Streu gut-kosten 41% Fremdleistungs kosten 2% External and overhead cost Personalkosten 29% Gemeinkostena nteil 6% Personal cost
Intelligent and compact devices for atmospheric measures WS600 Innovative principle (R 2 S) of measuring precipitation by means of microwave doppler radar. - Type of Precipitation (Hail, rain, snow, drizzle) - Intensity of Precipitation (mm/h) Measurement of wind direction ( ) and wind speed (m/s or km/h) by means of ultra sonic principle. = precise measurement without mechanical moving parts. Measurement of air pressure (hpa) (see level or absolute) Protection shield and active ventilation for measurement of air temperature ( C or F) and relative humidity (%) and Dew Point Temperature ( C or F). Digital communication with open protocol Power supply in one cable
Doppler Radar Precipitation Detector Principle 24 GHz microwave Doppler radar measures velocity and dimension of nucleus in order to detect type and intensity of precipitation Examples of typical distribution of velocity and dimension of precipitation nucleus for different type of precipitation rain snow Source: H. Mahlke, 2007, Distrometer
In pavement passive or active sensors
Intelligent and compact device for a complete road condition measurement Maintenance friendly removable Sensor inlet Innovative microwave radar measurement of waterfilm depth up to 4 mm (4000 µm) - Resolution: 0,01 mm - Accuracy: 0,1 mm + 20% Passive Measurement of salt concentration (% satt. or g/m 2 ) and Freeze Temperature ( C or F) by means of conductivity allow for waterfilm depth Surface condition detection by means of measuring the dielectric characteristic dry, moisture, wet, ice, snow, slush IRS31- UMB Surface Temperature and also 2 Sensor Interfaces for Subsurface Temperature ( C or F) (e.g. 30 cm) Digital data communication Interface (RS485) with open protocol
Active Measurement of Freeze Temperature by a compact Road Surface Sensor Maintenance friendly removable Sensor inlet Active Measurement of Freezing Point Temperature ( C or F) by means of cooling down and heating up of a very small area in order to detect the enthalpy change of forming ice without a significant impact of the surface condition. Surface condition detection by means of measuring the dielectric characteristic ARS31- UMB Digital data communication Interface (RS485) with open protocol
Non-Invasive Detection of Road Surface Condition Broad-band light emission Selective detection Adsorption spectrum of waterfilm
Non-Invasive Detection of Road Surface Condition NIRS31-UMB Selective detection of light adsorption at 3 (up to 8) different spectrum lines. reports: - Water-layer-thickness (µm) - Ice-layer-Percentage (%) or thickness (µm) - Snow-layer-thickness (mm) - Friction (0,00 1,00) Broadband light emission Reports Freeze-Temperature Non-Invasive! NIRS 31 IR detection Detects FOG! reports: - pavement surface temperature
Comparison passive/active/non-invasive surface sensors Comparison LUFFT IRS 31 LUFFT ARS 31 LUFFT NIRS31 Measurements IRS 31 ARS 31 NIRS31 Salt concentration X X Freeze point temperature X X Road surface temperature X X (option) Ice percentage (Ice in %) X Friction X Waterfilm X X Snow height (according to waterfilm) X X Precision certificate X X Depth temperature - 5 cm X Depth temperature - 30 cm X Forecast road conditions X Manufacturers certificate X X BAST-certificate X X Measurement principle Passive Active Passive Installation In-pavement Non-invasive 19 November 2012
Measurement of Visibility VS20- UMB Visibility Sensor Measurement principle: Optical IR Forward Scatter reports: - Visibility (10 2000 m) Inclusive Pole mounting equipment An optional ventilation unit can be implemented in order to prevent condensation problems under adverse conditions Additional analog Interface 4 20 ma provided! Digitale Data Communication Interface (RS485) with open UMB protocol, direct connection to ISOCON UMB Module
Lufft s professional installations
Proof of the Quality and Calibration Certificates Accurate measure of Waterfim depth is important not only for road condition but also for passive measure of Freeze Temperature! Every Sensor is shipped with a test certificate
Kiitokset esityksen seuraamisesta ja hyviä kelejä toivottaa ilkka.lilja@iloy.fi
Ps. 41. Päijännepurjehdus 19-20.7