WHAT’S NEW
10 iVTInternational.com February 2020
Avoiding AI
accidents
IN THE RUSH TO DEPLOY REMOTE AND MACHINE
CONTROL SYSTEMS, FUNCTIONAL SAFETY SHOULD
REMAIN THE CONSTANT GUIDING STAR FOR ALL
OFFHIGHWAY ENGINEERS
ConExpo, this year’s largest industry trade fair, is just around the
corner, and I expect that attendees will notice a clear trend: very likely
they will see that most large machine manufacturers (Volvo CE,
Caterpillar etc) and machine guidance manufacturers (Trimble, MOBA etc) are
delivering or developing systems for autonomous machinery, or at least semiautonomous
machine movements. This is a very exciting development and uses
technologies such as AI and machine learning that are becoming more prevalent
throughout society. What companies are aiming for is to increase productivity and
lower the threshold for fi nding new employees for construction fi rms. The
expression, ‘with great power comes great responsibility’ is true here. With
increased automation (power) you create new risks on a site, and these need to be
dealt with. How? With functional safety (responsibility) of course!
The foundation of every safe solution is a thorough risk assessment and that is
also where one should start with autonomous solutions. The suitable standard in
this area is called ISO 17757:2017 which is the result of a standardisation
committee’s hard and long risk assessment work to fi nd safe solutions in an area
of rapid development. The standard specifi es, “safety criteria both for the
machines and their associated systems and infrastructure, including hardware
and software, and provides guidance on safe use in their defi ned functional
environments.” ie. it includes requirements on both the machine and the work site.
But what is in it exactly? Let’s simplify things by considering three methods of
operation – and how to approach safety in each of them:
1 - Remote control
Remote operation requires full visibility of surroundings, and the level of safety is
similar to when an operator is present. If you can see the surroundings you would
also expect the operator to act as he or she would if they were in the machine
itself. In this case, besides stopping movements on demand, there should be a
safety cutoff if connection is lost and possibly also in the event of camera failure.
2 - Autonomous machine control
Semi-autonomous solutions help operator to perform specifi c work activities, such
as grading a slope. The operator is still in control of the machine as a whole but
gives his or her approval to the machine to take temporary control. While not easy,
implementing such a function is doable by a skilled programmer. Without
functional safety one cannot trust that the computer/PLC/electronic controller
will do what you expect. The supplier of the autonomous solution must make sure
that, to a verifi ed level of certainty, the program does not fail. A complex computer
(which may very well be needed to make all the calculations) is not a safety
controller. In other words, you probably need a safety solution that handles safety
and only allows movements under specifi c conditions.
3 -Fully autonomous vehicles
A fully autonomous fl eet is the dream of many OEMs and, given the ongoing
development of new technology, could one day be achievable. At this stage you
would need to keep track of all machinery and people in the surrounding area. The
simplifi ed way to approach safety would be to make sure nobody can enter the site
and that the machine cannot exit the site.
None of these automated methods of operation can exist without functional
safety. Tricky, boring and a drag on creativity? Well, the key is to keep the safety
solution small, simple and isolated from all the fancy operations. If you design a
safety function according to this principle, you will be able to set programmers
loose on creativity and still fulfi ll safety regulations. iVT
A Safe Pair of Hands
by Roberth Jonsson
“THE FOUNDATION OF EVERY SAFE
SOLUTION IS A THOROUGH RISK
ASSESSMENT AND THAT IS ALSO
WHERE ONE SHOULD START WITH
AUTONOMOUS SOLUTIONS”
About the author
Roberth Jonsson is an expert in functional safety for mobile
machinery, and runs the Zatisfy consultancy in Sweden.
Contact: Roberth.jonsson@zatisfy.se or +46705790027. www.zatisfy.se/ivt
ILLUSTRATION: IAN PARRATT, THECARICATUREARTIST.CO.UK
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