Kistler Holding Ag

David Cornu

Adrian Hofmann

Claudio Cavalloni

Reto Calderara

Leo Amstutz

Roman Strebel

Peter Frei

A method for calibrating a WIM (Weigh in Motion) sensor built into a road during travel of a calibrating vehicle measures the dynamic wheel force on the road and on the WIM sensor directly at the measuring wheel, depending on time or location. These wheel force data are transmitted to an evaluating unit. As the calibrating vehicle passes over, WIM signal data are simultaneously measured at the WIM sensor and transmitted to the evaluating unit. The wheel force data are synchronized with the WIM signal data in the evaluating unit. A calibration function is determined by comparing the dynamic wheel force data with the WIM signal data.

Method for calibrating WIM-sensors

A method for determining the weight G of a vehicle () while the vehicle is travelling on a section () of road () uses at least one weigh-in-motion (WIM) sensor () that is narrower than the length of the footprint of a wheel in the direction of vehicle travel. When the vehicle () travels along this section () of road () both the wheel loads F(t) of all the wheels () or twin wheels i, and the speed v(t) of the vehicle () during the entire passing are acquired as time functions, and during evaluation of the data for determining the weight G the speeds v(t) and their change over time are used as weighting of the simultaneously determined wheel loads F(t).

Method for weighing a vehicle, and measuring system and measuring arrangement therefor

A sensor module for measuring axle speeds and weights of double-track vehicles which travel in a direction of travel (L) along a carriageway with two lanes includes a plurality of piezoelectric strip sensors (A, B, C, D) that are arranged in a first lane group (I) and a second lane group (II). All the strip sensors (A, B, C, D) are spaced from each other in the direction of travel (L) via a secure longitudinal offset (LAD), which is greater than the maximum wheel contact length, and are offset from one another by between one centimeter and fifteen centimeters in the transversal direction. The sensor module also has a module length (LABCD) of less than 80 centimeters.

Piezoelectric sensor module of a WIM system for two-track vehicles and measurement method

An electronic circuit that changes a charge signal into a voltage signal within a sensor suitable for direct installation in a roadway can be connected to two single-core cables that need not be highly insulating yet can realize the required power supply of the electronics. The circuit includes an integrated impedance converter (IEPE) at the output to a two-core cable and a charge amplifier with an ICthat has two inputs. A capacitor Cc is connected in series to the signal output of the sensor at one input of the IC. A Zener diode D is arranged between the ground output of the sensor and the second input of the ICand can be supplied with power by a resistor Rin conjunction with a power supply arranged on the output side in order to adapt the potential at the second input of the IC

Charge to voltage conversion circuit for WIM sensor and WIM sensor with same

The invention relates to a sensor package () with long design for a WIM (Weigh in Motion) sensor (), comprising a first receiving plate (), a plurality of measuring elements (), which are arranged equally spaced in a row () on the upper side () of the first receiving plate (), an electrode () covering all the measuring elements (), insulation () completely covering the electrode (), and a second receiving plate (), which covers the insulation (). In particular, each receiving plate () consists of a plurality of receiving elements () the end faces () of which are juxtaposed in a row (). According to the invention, the inner end faces () of the receiving elements () of at least one row () have profiles () which engage in a form fit manner with the profiles () of the adjacent end faces () of neighboring receiving elements (). The invention further relates to a WIM sensor () comprising a hollow profile () with a tube () and two opposing mountings () arranged therein, between which a sensor package () according to the invention is arranged under initial tension.

Sensor package for WIM sensor and WIM sensor

A hollow profile sensor for installation in roads or a road surface for the purpose of sensing the weight of vehicles and/or driving dynamics reactions of vehicles or vehicle wheels to the road includes a tube part having a hollow interior profile. A counterpart is connected to the tube part. A measuring arrangement is held in the hollow interior profile between the tube part and the counterpart. A force introduction flange is connected to the tube part in such a manner that force application lines are concentrated on the measuring arrangement.

Two part hollow profile sensor

A WIM (weigh-in-motion) sensor has an oblong hollow profile and includes two force-transmission plates arranged parallel to each other. A tube is arranged between the plates and is integrally formed with the plates and defines a hollow space. Two supports that are arranged opposite one another are formed inside the hollow space, each support extending away from a respective plate and between which a measuring element is received centrally in the tube under preload. The tube includes two tube segments designed to be mirror-symmetrical with respect to each other, which join the plates together and on the inside adjoin the hollow space. The wall thickness of each tube segment has a relatively thick region between at least two relatively thin regions.

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Bellinzona, Switzerland

David Cornu