Weigh-in-Motion (WIM)
Weigh In Motion Preselection (WIM-P)
The TDS 821R/WIM-P system is developed from the statistical WIM applications (
WIM-S). The wheel, axle and gross weights are determined when a vehicle passes over the sensors. If pre-adjustable limits are exceeded, a data record, including video image with superimposed weights, time and date, is transmitted to a checking area, which is occupied by the police and/or BAG personnel (Federal Office for Goods Traffic).
The vehicle weights detected by the WIM-P system are checked at the checking area by means of calibrated scales, and if necessary appropriate measures are instigated against the driver and/or haulage contractor.
It has been shown that, in spite of the high investment in time and personnel, the psychological and educational aspect of WIM-P is not particularly great, as modern communications methods mean that an awareness of checks of this kind soon gets around and consequently reduces the success rate.
Optionally available hardware and software expansions:
- Photo and video camera (colour or black-and-white) which registers overloaded vehicles on all lanes in one direction of travel
- ANPR camera (Automatic Number Plate Recognition) for the automatic detection and processing of number plates of overloaded vehicles
- Hardware and software for image and data transmission to the checking area
As this process entails interfering with the flow of traffic and is very costly in terms of time and personnel, work is increasingly being carried out on processes for automatic overload checking (
WIM-E) for heavy goods traffic.
Sensors
LINEAS quartz sensors from Kistler Instrumente AG , which are available in lengths of 150 cm, 175 cm and 200 cm, are used for measuring weight. This enables rows of sensors to be arranged in any widths. Interference with the carriageway is minimal, as the installation depth is only 55 mm and the width of the slot only 72 mm.
The high-impedance signals of the LINEAS quartz sensors are converted into low-impedance output signals by a multi-channel charge amplifier, and subsequently digitalised by means of an A/D converter.
Signal processing
Wheel, axle and axle group loads (double and triple axles) as well as the gross vehicle weight are calculated from the data. The time stamp for the data has a resolution of 10 ms. Classification by axle silhouette and total weight is carried out in accordance with TLS 2002, FG2, and the European COST 323 directives (European WIM Specification produced by the COST 323 Management Committee). External devices are monitored and controlled by means of function group FG6.
Software for a central unit is available for the automatic interrogation of data in an extensive network of traffic and axle load monitoring systems.
Technical data
- 1 to 6-lane WIM with 2 or 3 rows of sensors per lane
- Up to 8 lanes with double inductive loops
- Detector/classifi er with BASt certifi cation since June 2009, accuracy class A1 with300 m cable length
- Optimised for LINEAS sensors from Kistler Instrumente AG
- ARM processor
- Integral quad band GPRS/EDGE or UMTS modem
- Card holder for 3V SIM cards (front accessible)
- Integral FG2-EAK (optional control module, FG1, FG3 and FG6)
- RS 485 interface (local bus)
- RS 232 interface (modem)
- Mini SD card (front accessible)
- Battery-backed real-time clock with calendar, time zones and automatic summer/winter time (can be synchronised in operation via IEEE 1588 and NTP)
- 28-channel A/D converter 96 kS/s
- USB interface
- Ethernet interface
- Temperature range -25°C/+75°C
- 19-inch rack or desktop case
- Power supply 230V/50-60Hz or 12-28VDC
(Technical data are subject to change without notice)
