client (TRL Ltd) operates a range of transport research and test facilities.
A new facility has been built for testing components such as child seats,
wheel chair securing attachments, F1 racing car nose cones, etc.
JK Controls Ltd. have designed, built and commissioned the controls for
operating the test and recording results.
trolley carries the sample under test, which is projected along a track by
strong rubber cords using a patented design.
The trolley is then brought to rest by means of a rapid deceleration
apparatus or by impact with a solid steel wall, dependent upon the type of test
being carried out.
Controls supplied a PLC and SCADA based control system to handle the test
set-up, test sequencing, safety interlocking, data gathering and post-test
recording of results.
The system uses Microsoft Access for data set-up and results history,
Citect SCADA for operator interaction, and Mitsubishi Q series PLC for data I/O
and control. The
screen appearances of the software systems are customised to give a consistent
operator is able to type in a desired impact speed, the number of cords and the
diameter of the cords, as well as many other menu based test set-up
The trolley is weighed and the point of initial impact registered.
The trolley is winched back and the system then carries out a calibration
sequence using force and position measurements with calculations to determine the desired release
point for the trolley that will enable the final speed at impact to be within 1%
of the desired value.
At the onset of impact a high speed measuring phase is started which
gathers depth of impact data, checks its validity, stores the data and records
the greatest depth of impact prior to rebound.
Position measurement was a challenge due
to the rapid movement, deceleration and non-contact requirement of the
application. We researched several methods of measurement and carried out
extensive tests, finally settling upon a Sick-Stegmann laser system with rapid
enables measurement of impact depth to within 2mm and location of the trolley
over the full track length of 22 meters.
completion of the test further data is recorded regarding maximum acceleration
prior to impact and measured impact speed.
The stored energy at release and the energy actually imparted at impact
are calculated to determine the efficiency and hence refine the calibration of
Controls built the control panels and custom designed electronic systems for
speed measurement and calibration.