IEEE Robotics & Automation Magazine - September 2011 - 121

(a)

(b)

Figure 2. (a) Working on the vehicles at VisLab's facilities at the Parma University Campus and (b) VisLab team and vehicles ready to go.

Overland Network handled the
logistics organization (an important
issue since vehicles and people needed
to travel through several countries, most
of which require documents and visas
to cross their borders) and provided all
the support vehicles. Altogether, the
expedition's convoy included four electric vehicles (two traveling and two
transported while recharging their traction batteries), two trucks as spare parts
storage and mechanic shops, a car transporter with the electric power generator
on board, and four motor homes for
team accommodations when crossing
sparsely populated regions such as the
Siberian steppe and desert lands of
Kazakhstan (Figure 3).
Both crews (VisLab and Overland
Network) were organized in shifts:
VisLab had four experienced members and two students who drove the
motor homes during each shift, whereas the Overland Network had an
average of eight people between truck
and motor home drivers. A couple of
translators, a photographer, and a
filmmaker were also involved in the
expedition.

Autonomous Vehicle
Driving Patterns
The team chose a leader-follower
approach (also known as virtual towing) to face the different conditions
of road, weather, infrastructures,
temperature, traffic, and unpredictable behaviors of other road participants the vehicles would encounter
during the trip.
Simultaneously, two autonomous
vehicles were driven together but
with different behaviors: the first one
tracing the route for the second to
follow it driverless. Once the traction
batteries went flat, both vehicles were
swapped with the two charged ones,
enabling them to perform two to four
autonomous runs (about 240 km)
every day.
Most of the route was unknown
since for large segments no maps were
available. As such, it would have been
impossible to ask the vehicles to determine the route. Therefore, the convoy
was led by a vehicle in which the operators took control every time a decision on the road was to be taken. This
was the leader vehicle; it was manned

all the time and ran autonomously in
places where no decision had to be
made (e.g., on highways). The leader
also broadcasted its GPS coordinates
via radio. The second vehicle, i.e., the
follower, received the leader's GPS
position; this vehicle followed the
leader's route defined by very rough
GPS waypoints [differential GPS
(DGPS) was not available in many
areas] and refined its trajectory via
local sensing.
Since the vehicles were equipped
with the same sensor suite and an
identical control software package
during the trip, they could be tested
in all possible configurations (swapping couples and different couple's
leader with follower) to collect a
complete set of data. (All technical
details about VIAC will be provided
in a future issue.)
From Europe to Cathay
VIAC was carried out across several
countries with great technology and a
large amount of human effort. The
trip took more than three months,
and the convoy traveled a total

SEPTEMBER 2011

IEEE ROBOTICS & AUTOMATION MAGAZINE

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Table of Contents for the Digital Edition of IEEE Robotics & Automation Magazine - September 2011