ROBOTICS & AUTOMATION – PIPELINE INSPECTIONS
Horoshenkov’s robots are said to be
di erent. “They will bene t from the
developments in swarm robotics – where
individual robots are fairly basic in their
ability to perform tasks, but combined they
become organised and highly capable,” he
explains. “Also, we believe this technology
can be pervasive, so it’s not like one or two
pipes are inspected at a time; these robots
will be spread across a substantial part of a
buried pipe network. They can stay there
for a week or a few months, continuously
collecting data, and conveying this data, so
that engineers above ground can prioritise,
sensing from the data where a change is
occurring or is about to occur.
“The data will come in real time, so the
operators can potentially send cleaning
or repair robots.” External problems like
soil subsidence are more di cult to sense
directly, but can cause symptoms that
would also alert engineers.
The initial funding for the project is for
ve years. “We hope by the end to have a
working prototype that we can test in our
full-scale lab in She eld, and deploy it on
a dedicated site provided by our partners,”
Horoshenkov says. These partners will
include water utilities: “Within a year from
now, we will try to build a consortium,
led by an industry partner, and they will
hopefully get roll-on funding to develop this
technology.
“We want to produce hundreds of these
things and show how they can cooperate,”
says Horoshenkov. The University of
She eld recently opened the UKCRIC
National Distributed Water Infrastructure
Facility, which allows realistic testing: “We
can pump raw sewage or clean water over
a 40-metre section of pipe.” The pressure
in clean water pipes can be up to 10 bar, and
“there will be a network of pipes which will
be fairly complicated”.
“It’s quite an early stage,” admits
Horoshenkov, “but we have some ideas
for ways to propel them: we can have
legged robots for sewage pipes, which
mimic a spider”, though there are issues
with making the feet stick to the pipe
walls no matter what the conditions.
“In clean-water pipes, it will probably
be a combination of legged and swimming
robots. The ow velocity is so fast in the
daytime that they can be washed away. So
they’ll probably be clinging to the pipe walls
waiting for night, when the ow of water
is low.” Otherwise, propulsion could come
from another mechanism like wheels or a
spiral propeller drive.
POWER SOURCE
The initial concepts have a battery on board,
which could be charged via an inductive
(wireless) charging point: “There are already
tens of thousands of ow meters in pipe
networks, and you can adapt them.” Other
energy sources are intriguing: “You can
charge from the water ow, so they can
get some energy back while they’re waiting
for night-time. Alternatively, you can pump
radio frequency energy down the pipe.”
Communication with or between
robots is a challenge: “It may be a hybrid: RF
wouldn’t go far in a water pipe, so you would
rely on acoustic or optical means”. In a sewer
pipe, where of the cross-section is dry, RF or
sound waves are feasible.
Horoshenkov says that “you can
inspect 30km of pipes using maybe a
dozen robots”. The process might take
weeks, and it is dependent on the search
program used. When it comes to sensors,
initially “we would use sound”. Generating
sound waves and analysing them is cheap.
Vision systems are good, but they require
too much processing power and storage.
“We’d use sound to nd approximately
where something had gone wrong and use
ultrasonics to inspect in detail. But we also
don’t discard other means of testing, like
inductive sensing, visual, infra-red and RF
sensing.” Sensing is equally important for
navigation: “That’s the biggest challenge
– we have to use all this synergy of sensing
to map the system, and to tell the robots
where they are.”
While current systems tend to
concentrate on inspection, some rms are
looking at maintenance/repair techniques:
grouting (resin to seal cracks or corrosion)
has been tried, and OC Robotics has
demonstrated a ‘snakebot’ laser welding a
pipe from inside. A project called FSWBot
aims to use technologies such as friction
stir welding, and to demonstrate a system
conducting a patch repair in steel.
The BIKE crawler
GE Inspection Robotics has developed
a modular crawler platform called
BIKE. It was recently used in a hydroelectric
power plant to inspect a water
turbine chamber and pipework that
would normally be inaccessible without
shutdown.
The BIKE uses four highly-articulated magnetic
wheels and can negotiate vertical walls, concave and
convex obstacles and also follow circumferential paths inside pipes. It weighs less
than 10kg, can be deployed through a 300mm hole, and is freely manoeuvrable in
a 375mm pipe.
The platform can be equipped with several di erent sensor types: for instance,
an ultrasonic probe for wall thickness measurements; water pumped between
the probe head and the surface acts as a couplant for the ultrasonic signal; eddycurrent
sensors can reveal cracks; and 3D laser profi ling is another option.
June 2019 www.operationsengineer.org.uk 11
Mulderphoto/stock.adobe.com
The iPEK Rovion RX400 crawler is
suited to larger diameter pipes
/www.operationsengineer.org.uk
/stock.adobe.com