Lufft in sääsensorit maa ilman teillä
Ely-keskus Kouvola Tiesääpäivät
3-4.6.2013
[email protected]
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
Taumittel/Streu
gut-Kosten
41%
Deicing
material
Fremdleistungs
kosten
2%
External and overhead
costGemeinkostena
nteil
6%
vehicle expenses
Personal cost
Example of the distribution
of typical winter
maintenance expenses
Fahrzeug/Gerätekosten
22%
Personalkosten
29%
Intelligent and compact devices
for atmospheric measures
WS600
Innovative principle (R2S) 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
Source: H. Mahlke, 2007,
Distrometer
snow
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/m2) 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
IRS31UMB
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
ARS31UMB
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
Salt concentration
X
X
Freeze point temperature
X
X
Road surface temperature
X
NIRS31
X (option)
Ice percentage (Ice in %)
X
Friction
X
Waterfilm
X
X
Snow height (according to waterfilm)
X
X
Precision certificate
X
Depth temperature - 5 cm
X
Depth temperature - 30 cm
X
Forecast road conditions
X
Manufacturers certificate
X
X
BAST-certificate
X
X
Passive
Active
Measurement principle
Installation
19
X
In-pavement
November 2012
Passive
Non-invasive
Measurement of Visibility
VS20UMB
Measurement principle:
Optical IR Forward Scatter
Visibility Sensor
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
[email protected]
Ps. 41. Päijännepurjehdus 19-20.7