Driver Operated Weighbridge SystemsWeighbridge Controller


Unmanned, or driver-operated, weighbridges are now becoming more commonplace.

Driver operated weighbridges dispense with the need for a person to be allocated to
the operation of the weighbridge, full or part time. They allow the wagon drivers
to become their own weighmen, whilst at the same time giving maximum security
of information in spite of little or no driver training.

Rontec have wide experience in the specialised field of unmanned weighbridges.
Our equipment is chosen by some of the biggest weighbridge users in
the country and has a proven track record of reliability and successful operation
over a number of years

When to consider unmanned weighing

The unmanned option is suitable for almost any weighbridge application, but the greatest benefits are seen when
repetitive runs are being made by wagons delivering or collecting materials. The initial cost of installing an
unmanned system can be quickly repaid by savings on personnel and the speed and accuracy of the
data that is automatically captured by the system. Obviously, the busier the weighbridge is,
the greater the potential advantages.

What is involved in choosing unmanned?

In law, the weighbridge operator is responsible for ensuring that the weights obtained from the weighbridge are
correct. In practice, this means that he has to check two things before taking a reading:

  1. That the weighbridge is set to zero before the vehicle drives on to the platform.
  2. That the vehicle is correctly positioned on the platform.

The wagon driver will have no way of knowing whether or not the weighbridge is reading zero without stopping and
getting down from his cab and so it is a requirement that the zeroing operation is done automatically.
This is normally accomplished by having induction loops in the roadway about 5 metres before the platform
—- at both ends if the weighbridge is to be used in both directions. When the wagon passes over the loop,
a signal is sent to the weighbridge control system and the digital weight indicator is zeroed automatically.
If for any reason this does not happen, the driver is advised by the system and the weighing cannot proceed until
the platform is emptied and the zeroing procedure repeated.

To make sure that the wagon is correctly positioned on the platform the weighbridge is fitted with either rising
traffic barriers or infra-red beams across the ends of the platform. In this way the weighing can be prevented if
the wagon is not properly placed on the weighbridge.

So, in addition to the usual weighbridge equipment an unmanned system at its simplest needs:

However, to get the best out of an unmanned system it is much better to go a step further.
Only when automated driver input, data logging and full traffic handling are incorporated does an unmanned
system really come into its own and start to pay back the investment put into it. The traffic handling can be carried
out by the Rontec control system that oversees the running of the weighbridge and a Personal Computer,
in the weigh office or elsewhere, will log all the weighing details on to its hard disk.

RF Tag system

Non-contacting RF tags, which can be supplied in a variety of shapes such as key fob, credit card, etc.,
may be specified as an alternative to Datakeys. These tags hold a single and unique identifying code on them that
cannot be changed, but is used to look up full details held on the computer. These would normally comprise
registration number, stored tare weight (optional), operator name and address and any other data permanently
associated with that vehicle.

The driver holds the tag against the face of the reader, which may be in the weigh cabin or outside on a pole so
that it can be accessed without leaving the cab. Everything else is then automatic. If the system is fitted with a
touchscreen, the driver can be selected, such as vehicle allocated to him, material carried, etc.,
all on drop-down lists.

On returning to the weighbridge for the second weighing, the driver again holds the tag against the reader and
the system recognizes that it has details of the first weighing, so it knows that this must be a second weighing.
The difference between the first and second weights is logged as the net weight and the date, time and consecutive
running number is also recorded as described below in the computer section.

The standard RF Tags are credit-card size, but for special applications many alternatives are available, some of
which can be read at long distance from the sensor.

The Rontec Datakey system (Alternative to RF Tags)

The Rontec Datakey System is a tried and tested means of getting the maximum amount of information from the
driver and into the weighbridge control system quickly. It comprises a rugged plastic key in which is embedded an
EEPROM chip that can hold hundreds of characters. The weighbridge control system can read the chip and,
if required, write new data back on to it. All the driver has to do is to insert the key into a receptacle and turn
it through 90 degrees. The display then guides the driver as to what is happening and asks
him to remove the key when the operation is over.

Rontec will tailor the system to do what you want it to do. The key may hold nothing more than the wagon's
registration number, allowing the weighbridge system to look up its tare weight, owner and other details; or it may
hold a great deal more information that is read into the weighbridge control system's memory.

Automatic Number Plate Recognition System

If you wish to identify the vehicle automatically, either to enter its registration number into the weighing record or to
compare it with that held on the system against the RF Tag or Datakey, Rontec can offer a fully automatic number
plate recognition system. A camera is trained on the vehicle and by using optical character recognition is able to
feed the registration number into the computer to be logged against the record being written. If the RF tag or
datakey has a vehicle or vehicles associated with it and the number read by this system is not one of those,
then the computer can take appropriate action, such as logging a warning or alerting Security.

The Personal Computer

The PC provided with the system is a standard unit, which means that maintenance is greatly simplified. No obscure additional cards or devices are required. In the unlikely event of computer failure, the original PC can be exchanged
for another similar one — even by the owner of the system.

The transaction file, in Microsoft Access ® database format, holds one record for every pair of weighings made.
The second weighing is automatically linked to the first weighing, using the registration or fleet number as a unique
"key". It is this file that forms the basis for the reports that can be produced by the computer. Rontec can provide a
series of report formats to give printed details of business transacted in any form, whether customer, date or period
based, or in any other configuration required. Alternatively, the data can be exported into a proprietary
spreadsheet, such as Microsoft Excel ®.

Some of Rontec's larger customers have the PC linked by Modem to control centres or head offices, possibly
hundreds of miles away from the weighbridge. This enables them to read the transaction file on the PC's hard
disk drives at any time and to keep track of weighings being carried out right up to the moment of interrogation.

The Rontec traffic control system

For busy weighbridges with a lot of vehicles to handle, Rontec can provide the answer to traffic congestion.This can
be particularly acute if the weighbridge is used in both directions, where there is often a risk of wagons meeting
"head on" at the weighbridge. The whole idea of traffic control is frequently overlooked, yet it is in fact very
important. It is useless to have a fast and efficient data collection system at the weighbridge if access to and from
the platform is slowed down because of vehicle congestion.

Rontec's solution is to provide holding areas some distance from the platform itself. These are controlled by traffic
barriers or lights, linked into the main weighbridge control system. By keeping track of vehicle flow the system is
able to retain wagons at the holding areas until the weighbridge is clear and ready to accept them. If space on
site is limited, the system can even bias the flow in such a way that wagons leaving are given priority
over those arriving.

Whether or not to choose the unmanned option is an important decision. In terms of equipment it is of course
considerably more expensive than a conventional weighbridge with an operator in attendance at all times. In terms
of overall costs taken over, say, three years, a very different picture emerges. It is not just the saving in manpower
which has to be considered, but also the faster weighing rate achieved, the large volume of data which can be
collected and recorded very quickly and, perhaps most important of all, the accuracy of the information recorded
on both ticket and computer.