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The plane was in mid air over the South Atlantic
approaching the Inter-Tropical Convergence Zone, the
area where air masses coming from the different
hemispheres converge at the humid equatorial
latitude, with electrical storms as a result. Suddenly
the automatic flight management system lost speed
input from the triple redundant pitot tubes (which
were all clogged by ice) and handed, what had up to
then been a fully automatic airplane, into the hands of
the relatively inexperienced junior pilot flying.
The accident investigation tells a horrifying story
of mismatch between the automation interface and the
pilots trying to make sense of what they saw on the
screens. The highly automated flight system, which
interfaced the human and the machine through
sophisticated computer programs that in this case was
difficult to understand and handle correctly. The
automation can prevent human mistakes when
everything works as planned by the engineers, but
became incomprehensible for the same operators
when computers did not receive proper inputs and
went blind [4].
After the accident, accusations were made
regarding loss of basic skills of manual flight (e.g.
[10]). Was it that liner pilots had lost their skills and
their capability to manually fly a plane, because of the
use of autopilot and of the overwhelming technology?
Bainbridge [1] remarked that skills deteriorate when
not used and a formerly experienced operator
monitoring an automated process may well have
turned into an inexperienced one. Then when manual
take-over is needed there is likely something wrong,
so that unusual actions will be needed to control it,
and one can argue that the operator needs to be more
rather than less skilled.
When designing a new workplace for marine
watch officers moving into a shore-based Remote
Operation Centre, one might envision such a loss of
skills. How long will it take for an experienced deck
officer to become unexperienced? Having forgotten
the inertia and dynamics of maneuvering a big ship in
heavy seas or birthing in an intricate dockland? Can
this be avoided? Can we replace individual experience
with expert-systems? The challenge is enormous. Let
us do some design sketching of such systems to
support decision-making in a ROC.
I will sketch two concept solutions: how to keep
the operator in the loop during communication
glitches and how to quickly bring the operator into
the loop if he or she has been “absent” and there is a
sudden alarm situation.
3 THE DECISION SUPPORT SYSTEM AND ITS
“DIGITAL TWIN”
Let us assume that we can collect this nautical
experience in an expert-system capable of making
decisions and transparently showing the monitoring
operator its current status of knowledge (the input
from sensors on the remote ship) and what it is
planning to do (its intentions, plan A, B and C…).
Let us assume that all necessary data from the ship
is communicated to the ROC through some kind of
communication system (satellite, 5G, Maritime
Broadband, etc.). Our experience tells us that we will
have communication glitches or outages from time to
time. In the MUNIN project we said that a MASS that
has lost communication with its control centre should
stop in a “fail-to-safe” mode. Now, stopping in the
middle of whatever situation the vessel might be in
might not always be the smartest action. Smarter
would be to go to a “minimum risk conditions” [5],
meaning that the ship will do what is best given the
current circumstances: in the middle of the ocean,
with no other ships within 30 nautical miles, the ship
might just as well carry on its course for some time
waiting for communication to come back. But in a
densely trafficked shipping lane in the English
Channel, the ship could check for oncoming vessels
on its starboard quarter and then proceed out of the
Traffic Separation Scheme and stop and hover on its
DP (or anchor) while sending relevant pre-recorded
messages on VTH channel 16 and hoisting relevant
signals. And most important of all is that we realize
that, having lost communication, decisions must made
by the expert-system on the ship alone. The
automation will have the final say.
What if we see it from the remote operator point of
view: suddenly the communication link with the
vessel is lost. Camera and radar images go blanc,
own-ships-symbol disappear from the ECDIS. The
operator is now in the back. But for some time on he
or she could extrapolate ships motions into the future.
This is where the “digital twin” comes into the
picture.
3.1 The expert-system digital twin
As mentioned above the expert-system on the
autonomous ship is the one deciding on how to move
into minimum risk condition when the vessel has lost
communication with the ROC. The expert-system
onboard is normally constantly updated by sensors
onboard, as well as with information from the ROC
and from others (e.g. AIS messages from surrounding
ships, information from traffic centers like a VTS, etc.).
If an exact copy of the expert-system onboard are also
present in the ROC and is simultaneously updated
with the same information as the one onboard, the
system ashore should make the same decisions as the
one onboard. Now, if communication is lost and the
operator loses his eyes and ears of what is going on
onboard, the digital twin in the control room will for
some time continue to extrapolate the situation into
the future. It might even be able to catch AIS
information through other vessels and coastal radio.
The operator could then with probability see a
simulated reality, where the digital twin demonstrates
the same actions for some period of time in the ROC.
Such a simulation will soon become obsolete, but a
might keep the ROC operator in the loop over a short
communication glitch.
Another problem is when an operator that has
been attending other vessels suddenly is summoned
by an unexpected alarm from one of his ships he has
not been attending for some time.