With a bold new twin-chassis design, our ground-breaking GRAID robot is on track to transform the way National Grid inspects previously unreachable sections of its network. Project Lead David Hardman shares the latest as this innovative pipe dream gets closer to reality.
Human fascination with the power of machines has remained undimmed for decades. So it’s no surprise that our latest robotic innovation – Project GRAID – has been capturing the imagination of everyone from the national press to the gas industry, our customers and stakeholders.
The project began back in 2015 with the ambition to develop a robot that could be sent into high-pressure gas pipelines to analyse their condition. It marked a real step change in technology for us – a move away from predictive modelling into a brave new world of high-end robotics.
We had a strong reason for driving this technology forward. You see, our business is responsible for maintaining almost 8,000km of underground pipes transmitting – at high pressure the gas that keeps homes warm and businesses running around the UK.
Moving beyond the power of PIGs
Most of these pipes can be inspected using devices called pipeline inspection gauges, or PIGs. These cylindrical objects are forced down sections of pipework by the force of the gas inside and they collect data via onboard sensors as they move.
While they do an important job for us, roughly 350km of pipes can’t be inspected in this way. These parts of the network have features such as bends, vertical sections and other obstacles that PIGs simply don’t have the ability to navigate.
This is where GRAID comes in. This leap in robotic technology means we’ll have a platform that can negotiate previously unreachable areas for the first time.
Right now, we’re two years into the project and our robot is really thriving. Alongside partners Synthotech, Premtech and PIE we’ve finalised the robot’s design and built a stunning prototype.
The design process was a carefully considered evolution. The first model used nature as its inspiration. Influenced by the aerodynamic shape of the dolphin, it gave us the streamlined look and robustness we needed to operate effectively under the pressurised conditions it would face, up to 100 Barg.
Two proves better than one
After further reflection, we revisited our approach. So what was previously a single unit is now two connected modules, a bit like a truck pulling a trailer. This gives the robot better steering and agility.
The new design also features four driving tracks in place of the previous two. These give the robot more magnetic contact with the pipe’s wall and, much like a 4×4 car, better grip and traction.
Another integral part of the design is a robust mounting point on which to fix specially developed Electromagnetic Acoustic Transducer (EMAT) sensors. In simple terms, this is the part of the robot that will rotate 360 degrees, collecting wall-thickness data and detecting defects as it moves through our pipes.
We’ve also developed an Umbilical Management System (UMS). This is a sophisticated trolley and cable that acts as our connection to the robot under live conditions. It allows us to send drive commands in one direction and feed data back to our control centre the other way.
Saving UK gas consumers £60m
All the research and technology we’ve developed adds up to a mighty little robot that will be able to precisely detect corrosion, leaks and other issues.
Better information means we can make better-informed decisions on both the work we do and when we do it. We estimate this will save us around £60m over the next two decades by eliminating unnecessary excavations and allowing us to extend the life of assets in certain cases.
The latest chapter for GRAID is a long and detailed testing process. Alongside partners DNV GL, we’ve developed and built a test rig for use in offline trials. This recreates the conditions of a real-life high pressure network, complete with 90-degree bends, 45-degree climbs, full vertical sections and the ability to be pressurised to the levels the robot will experience in live pipelines.
On trial and acing its tests
Offline trials are well under way. We’ve conducted a variety of tests including geometry trials, disaster recovery and endurance challenges. So far, the robot is performing just as we’d hoped. It moved and operated successfully in early tests at normal atmospheric pressure and in the coming months the test rig will be pressurised and the trials will continue. So we’re very pleased with how things are proceeding.
Looking towards 2018 we will begin online trials at live installations. Once complete, we’ll look to get GRAID fully implemented into our business late next year.
To finally see our robot rise from a great idea on paper to actually moving around pipework and sending accurate images back to the control centre during testing has been both exciting and inspiring. It really brings home how close we now are to making this a reality for our business – and our customers.