Beneath our streets lies a maze of pipes, conduits for water, sewage, and gas. Regular inspection of these pipes for leaks or repair typically requires them to be dug up. The latter is arduous and expensive, with an estimated annual cost of 5.5 billion pounds in the UK alone. It also disrupts traffic and is a nuisance to people living nearby, damaging the environment.
Imagine a robot that can find its way through the narrowest of pipe networks. That robot could relay images of damage or obstructions to human operators. This isn’t a pipe dream anymore, shows a new study in Frontiers in Robotics and AI by a team of researchers from the University of Leeds.
“Here we present Joey—a new miniature robot—and show that Joeys can explore real pipe networks completely on their own, without even needing a camera to navigate,” said Dr Netta Cohen, a professor at the University of Leeds.
Joey is the first to navigate all by itself through mazes of pipes as narrow as 7.5 cm across. Weighing just 70 g, it’s small enough to fit in the palm of your hand.
Pipebots project
The present work forms part of the “Pipebots” project of the universities of Sheffield, Bristol, Birmingham, and Leeds, in collaboration with UK utility companies and other international academic and industrial partners.
First author Dr Thanh Luan Nguyen, a postdoctoral scientist at the University of Leeds who developed Joey’s control algorithms (or “brain”), said, “Underground water and sewer networks are some of the least hospitable environments, not only for humans but also for robots. Sat Nav is not accessible underground. Joeys are tiny, so they have to function with very simple motors, sensors, and computers that take little space, while the small batteries must be able to operate for long enough.”
Joey moves on 3D-printed “wheel legs” that roll through straight sections and walk over small obstacles. It is equipped with a range of energy-efficient sensors. They can measure its distance to walls, junctions, and corners, navigational tools, a microphone, and a camera and spotlights to film faults in the pipe network and save the images. The prototype cost only 300 pounds to produce.
Mud and slippery slopes
The team showed that Joey could find its way, without any instructions from human operators, through an experimental network of pipes including a T-junction, a left and right corner, a dead end, an obstacle, and three straight sections. On average, Joey explored about one meter of pipe network in just over 45 seconds.
To make life more difficult for the robot, the researchers verified that it could quickly move up and down inclined pipes with realistic slopes. They added sand and gooey gel (actually dishwashing liquid) to the pipes to test Joey’s ability to navigate through muddy or slippery tubes. They found success again with this test.
Notably, the sensors allow Joey to navigate without turning on the camera or using power-hungry computer vision. This saves energy and extends Joey’s current battery life. Joey will return to its point of origin whenever the battery runs low to “feed” on power.
Joeys have one weakness: they can’t right themselves if they inadvertently turn on their backs, like upside-down tortoises. The authors suggest that the next prototype can overcome this challenge. Future generations of Joey should also be waterproof to operate underwater in pipes filled with liquid.
Pipebots future is collaborative
The Pipebots scientists aim to develop a swarm of Joeys that communicate and work together, based on a larger “mother” robot named Kanga. Kanga is currently under development and testing by some of the same authors at Leeds School of Computing. It will be equipped with more sophisticated sensors and repair tools, such as robot arms, and carry multiple Joeys.
“Ultimately, we hope to design a system that can inspect and map the condition of extensive pipe networks, monitor the pipes over time, and even execute some maintenance and repair tasks,” said Cohen.
“We envision the technology scaling and diversifying, creating an ecology of multi-species of robots that collaborate underground. Groups of Joeys would be deployed by larger robots that have more power and capabilities but are restricted to the larger pipes. Meeting this challenge will require more research, development, and testing over 10 to 20 years. It may start to come into play around 2040 or 2050.”