Posted on by Eva Szalma

M1S2 – Measuring the on-board weighting of heavy vehicles

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Author

László Ketskeméty

Mini Project ID

BMEMPLOAD1

Description

The case: Illegal overweighting of heavy goods vehicles is a major problem throughout Europe. Heavy goods vehicles, buses and coaches transporting goods in Europe must comply with certain rules on weights and dimensions for road safety reasons, and to avoid damage to roads, bridges and tunnels.

There are two possible solutions for determining the mass of heavy vehicles. Both measurement techniques have been common practices for decades, but there is currently no uniform European regulation for them. Both OBW and WIM techniques are suitable for inspecting overloaded trucks and tracking their impact on the road. In the case of OBW technology, it is possible to link the data of the vehicle and the carried weight to the sections of the road network, in the case of the WIM system we connect a specific road section and a measured load weight to a specific vehicle. In OBW tracking, the car and weight are constant, the road section changes during movement, in WIM measurement, the road section is constant, on which the weight data and the data of the carrier vehicle are constantly changing. In this sense, we are talking about a mapping and its inverse.

WIM systems

Weighting In-motion (WIM) devices are designed to measure and record the gross weight of the axle and vehicle as vehicles pass through the measurement site. Unlike static scales, WIM systems are capable of measuring vehicles traveling at reduced or normal speeds and do not require the vehicle to stop. This makes the measurement procedure more efficient and, in the case of commercial vehicles, allows trucks under weight limitation to eliminate static scales or inspections, which would mean a significant loss of time and loss of traffic for them.

WIM systems measure the dynamic axle load of vehicles and try to calculate the best possible estimate of the associated static values ​​from this data. WIM systems must operate unattended under extreme traffic and environmental conditions, often without any control or restriction on vehicle movement or driver behaviour. For on-road WIM systems, this applies to total vehicle traffic. Let’s go over the advantages and disadvantages of building road WIM systems.

Advantages:

  • As the measuring device is built into the road, information can be obtained from all vehicles passing through the measuring point, including vehicles that are not equipped with a weighing device.
  • In-motion weighing systems can be used as part of traditional road checkpoints or as part of virtual checkpoints.
  • It can be used to obtain accurate data on the traffic and weight load of the road section belonging to the measuring point. The fourth force law states that the rate of damage to the road surface is proportional to the weight of the axle raised to the fourth power. The WIM data contains information about the number of axes for each significant weight category, which allows this type of calculation to be performed.
  • By organizing the measuring points into an appropriate network, connecting the obtained databases, global information about the entire road network can be obtained. In this way, the dynamic modelling of the traffic and weight load of the road network becomes possible.

Disadvantages:

  • Continental construction of a well-used WIM measurement network is a very expensive and lengthy process. To operate, a large number of metering station systems would need to be installed at appropriately selected locations to achieve a high compliance check density. WIM systems also cost around € 100,000 per site (at different prices depending on accuracy requirements). WIM is the technology of the future, but it would be too expensive to implement in the present.
  • Weighing must be supplemented by the installation of other devices. A vehicle identification system with license plate recognition is required. This is again a cost-increasing factor.
  • The accuracy of motion-weighted data is generally much lower than for static scales, where the environment is better controlled.

Known WIM measuring points can be easily avoided by overloaded vehicles by redesigning the route, so they cannot be penalized.

OBW systems

OBW (On Board Weighting) is installed on vehicles. As it is not closely linked to the infrastructure, it allows weight data to be transmitted from the moving vehicle to the roadside inspection authority at any time if an inspection order is received on board. The OBW technique is related to the radar technology of speed measurement, as the inspectors receive the weight data immediately as the vehicle passes.

In order to implement the mandatory on-board weighing solution, the following requirements must be met:

  • Cheap equipment
  • Appropriate level of accuracy
  • Calibrated and certified equipment
  • Standardized communication interface

Currently, OBW systems are less than € 1,000 per truck (the average price of new trucks is over € 95,000) and are available for all types of vehicles. In such cases, such systems become mandatory and are lined up during production for all models, reducing hardware costs by up to € 500.

The certification system and the recalibration cycle are the same as for the digital tachograph. However, practical procedures need to be further developed to reduce the workload and thus the costs of the (re) calibration process. Communication with roadside inspectors shall be via the short-range radio interface defined by the CEN DSRC standards in force. In summary, the conditions for the efficiency, affordability and reliability of OBW are met.

Advantages:

  • Accuracy – less than 3% is possible for long-term operations.
  • Reliability – use high-security methods for data collection, storage, and transmission.
  • Reliability – long intervals between (re) calibrations of the system (up to 2 years).
  • Robust – design and manufacture parts to meet automotive requirements.
  • Transparency – use of proven and accessible automotive standards (such as SAE1939).
  • Mass determination and overload indication can be performed for each vehicle axle.
  • Infrastructure – use the existing infrastructure of the tachograph system for standardization, certification, identification, installation, calibration, training and implementation.
  • Installation wiring – the system can be designed to support installation processes at the vehicle manufacturer.
  • Scalability / Flexibility – The use of common standards allows the system to be expanded with additional / heterogeneous sensors as needed or required (e.g. ABS, EBS).
  • “CO2” – Reducing operating costs is possible due to reliability, scalability, flexibility, and use of existing infrastructure.

Disadvantages:

  • This technique cannot be installed in all vehicles on the road due to its relative cost. In the case of passenger cars, commercial vehicles and buses, the installation of an OBW measuring instrument enabling serial measurement would entail a significant cost. It would not be advisable to order their mandatory installation, as the weight gain during their transport compared to their net weight is close to the measurement error limit.

There are many heavy vehicle manufacturers, many of which belong to countries outside the EU. It is difficult to regulate the type of OBW devices to be installed and the requirement for regular calibration.

Sector

VET

Data

A kétféle rendszer elemei működnek, országonként eltérő kiépítettségben. A tisztánlátáshoz egy egységes BIG DATA adatbázist kell létrehozni, amely tartalmazza az alábbi adatokat:

  • Szükség van a már letelepített és közeljövőben megépítendő, a tervekben szereplő WIM mérőpontok listájára, GPS koordinátáira, a letelepített berendezés típusára, paramétereire.
  • Annak eldöntésére, hogy a megfelelő mérési sűrűséget meg lehessen állapítani, szükséges az összes autóút bekötőútjainak listája és a bekötési pontok GPS koordinátái. Egy-egy ilyen útszakasz 2 km-estől akár 70 km-es szakasz lehet, ahogy az autóút bekötői megépültek. Egy adott szakaszon minden belépő járműnek biztosan végig kell haladnia. Így lehet követni, hogy egy az útpályán közlekedő, már regisztrált gépjármű hol lép ki a rendszerből. Ez egy meglehetősen nagy adatbázis elkészítését jelenti.
  • A tagországoknál forgalombahelyezett nehézgépjárművek egyesített európai adatbázisát létre kell hozni, amely tartalmazza, a felszerelt OBW mérőeszköz típusát és paramétereit.
  • N2 és N3 típusú nehézgépjárművek gyártóinak a listája, akiket majd kötelezni kell a súlymérő műszerek beépítésére.
  • A jogi szabályozás koordinálásához szükség van a tagországok érvényes szállítmányozási szabályzataira, rendeleteire.
  • A tervezéshez fel kell mérni a közutakon közlekedő nehézgépjárművek számát országonként.
  • Ajánlatot kell kérni gyártóktól WIM és OBW műszerek gyártására. Milyen költségvonzata lehet EU szinten az egyes megvalósítható tervezeteknek?

Model

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Calculation

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Solution

The elements of the two systems operate in different configurations from country to country. For clarity, a single BIG DATA database should be created that contains the following data:

  • The list of WIM measuring points that are already functioning or to be built in the near future, the GPS coordinates the type and parameters of the installed equipment.
  • In order to decide on the appropriate measurement density, a list of access roads for all roads and the GPS coordinates of the connection points are required. Each such road section can be as long as 2 km, up to 70 km, as were the motorway connections built. All vehicles entering a given section must be sure to pass. This way you can keep track of where an already registered vehicle on the road is leaving the system. This means creating a large database.
  • A common European database of heavy-duty vehicles placed on the market in the Member States should be set up, containing the type and parameters of the OBW measuring device fitted.
  • A list of manufacturers of heavy-duty vehicles of types N2 and N3 who will be required to install weighing instruments.
  • The coordination of legal regulations requires the valid shipping regulations and ordinances of the member states.
  • The number of heavy vehicles on public roads by country should be assessed for planning.
  • A quote must be requested from manufacturers for the production of WIM and OBW instruments. What could be the cost implications of each feasible project at EU level?

Presentation

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Review M1S2 – Measuring the on-board weighting of heavy vehicles.