System ważący pojazdy MS-WIM

System ważący pojazdy MS-WIM

Accurate multisensor systems for weighing vehicles in motion. Research Project No 4 T10C 026 25.

The project goal was the development and analysis of metrological characteristics of a MS-WIM system (Multi Sensor Weigh in Motion), which installed in the lane would allow for automatic measurement of parameters of vehicles, in particular axle load  and total weight, without imposing significant limitations on their speed or driving track.

A special feature of systems that are the subject of the project, significantly differentiating them from WIM systems constructed and currently used both in the world as well as in Poland, is several times smaller uncertainty of measurement results.

The project achieved the following objectives:

  • developed and verified parametric models describing the variability of individual axle load of the vehicle to the road while driving, for different classes of vehicles. These models were used to optimize the number and methods of deployment (along the track) of pressure sensors, evaluation of weighing resultsun certainty of any vehicle, and the analysis methods of calibration of the WIM system;
    the optimal choice of the number of sensors and their location was made, taking into account the cost of the measuring station, assuming uncertainty of measurement and the speed range and range-weighted vehicles; the first in Poland’s MS-WIM measuring station was constracted which enables weight control of trucks,
  • a system for acquisition and processing of measurement data was developped, taking into account the large number of sensors (a dozen or pressure sensors, several of inductive presence sensors, multiple sensors of surface temperature) and the requirements for the calculation speed (up to three vehicles weighed per second), the data storage capacity (archiving of motion data parameters for statistical purposes), and the data transmission to the host system (when the allowable pressure or total weight is exceeded )
  • carried out was an analysis of the accuracy and applicability of several algorithms for estimating the static pressure of each axle of the weighted vehicle and its total weight. Developed algorithms were implemented in the measuring system
  • carried out was an analysis of algorithms and correction of the influence of confounding factors of weighing result (temperature, speed changes, fluctuations in the vertical and lateral weighted vehicle) in the range of variation occurring at the location of the MS-WIM. Defined quantitative influence of confounding factors,
  • carried out was an analysis of different calibration methods of WIM systems and the impact of the chosen method of calibration on the weighing system accuracy . Based on the obtained results, field calibration was performed of the MS-WIM,
  • carried out was an analysis of the different calibration methods of WIM systems and the impact of the chosen method of calibration on  the weighing system accuracy. Based on the obtained results, calibration of MS-WIMc was performed
  • algorithms for the  measurement data fusion from individual WIM sensors were developed and validated, to minimize the distortive effects of the dynamic component, and to reliably estimate the static pressure and the vehicle weight,
  • the results were published in Poland and abroad (a total of 24 papers).

Contakt: dr hab. inż Ryszard Sroka


Location of the measuring station in Gardawice.


Plan of the MS-WIM measuring station.


Measuring station after installation


Working measuring system.