Lighthouse

What it does

Lighthouse is a low cost robot that can travel inside underground water pipes and proactively find leaks. Currently, water utilities cannot find leaks before they grow into costly pipe bursts. With Lighthouse, they can find leaks months before they break.

Your inspiration

Every day 20% of the clean water produced in the world is lost due to pipe leaks. Due to limitations in current technologies, most of the leaks are either not found, or found too late. Every year, there are 240,000 water pipe breaks in the US, and many of them cause sinkholes and other severe damage to the infrastructure. Water utilities need methods for detecting and locating such leaks before they become big breaks, so that they can perform preventative maintenance to save water and protect infrastructure. If we can find and fix half of all leaks in the world, we can recover enough leaked water to support 1 billion more people's daily need.

How it works

Robot Lighthouse is a rubbery robotic device that looks something like an oversized badminton birdie. Its key innovation is its skirt of soft tactile sensors. This skirt of sensors fill the diameter of of the pipe. When the robot passes a leak in a pressurized water pipe, these tactile sensors will be pulled by the suction force generated by the escaping water, and thus indicate a leak. The robot is made of soft material and it is very flexible. It can be inserted into the water system through any existing Tee junctions underneath fire hydrants. It then moves passively with the flow, goes around pipe bends easily, and logs its position and leak information as it goes. After retrieving the robot with a net through another hydrant, I can download the data from the robot wirelessly, and use my program to automatically generate a google map of leaks to present to utilities. No digging is required, and there is no need for any interruption of the water service.

Design process

Robot Lighthouse is the outcome of 6 years of my PhD research at MIT. It started with a request from Saudi Arabia, where 30% of their desalinated water is leaked in the pipes. The problem is, those leaks cannot be detected by existing tools because the pipes are plastic but the existing tools only work in metallic pipes. I have to design new leak sensors. It took 3 years, 11 prototypes and numerous lab experiments before I demonstrated the first working robot at an industrial testing facility in Saudi Arabia. The first challenge was to design a robot that can maneuver through real water pipes with Tee junctions, elbows and diameter changes. I solved the problem with a soft robot design, one of its first kind. Based on hydrodynamic studies, I also designed the membrane sensor to detect the suction force generated by leaked water. However, it failed the first field test in 2015, as the turbulent water flow in pipes rendered the sensor ineffective. It took 2 more years of hydrodynamic analysis, modeling, prototyping and testing before I demonstrated the first sensor that can detect leaks in live water pipes. Built upon this success, I further iterated the design to improve the sensor's noise rejection capability and invent a new localization algorithm that do not need GPS.

How it is different

Lighthouse can easily find the hard leaks while competitors cannot. The existing methods mostly search for the sound of the leaks. In practice, popular devices such as geophones and acoustic correlators can find leaks losing 10 gallons of water per minute, and that is twice the flow rate of a typical shower. Lighthouse, with its unique tactile sensor, can find leaks that are as small as a 4 millimeter crack that loses just one gallon of water per minute. That is 10 times improvement on sensitivity, that enables Lighthouse to detect leaks when they are small, many months before they become big problems and interrupt the water service. Moreover, the other technologies works well only in metallic pipes but not in plastic pipes. This leaves countries like Saudi Arabia where most pipes are plastic, unable to maintain its pipes effectively. Lighthouse, with its unique tactile sensor, can find leaks equally well in pipes of any material.

Future plans

After being my PhD research project at MIT for 6 years, Robot Lighthouse is now the core technology of my startup, WatchTower Robotics Co. I founded WatchTower in July 2018, and now Watchtower is part of Techstars Sustainability Accelerator. Through Techstars, I want to build this company ready for growth and impact. At the same time, WatchTower is continuing to acquire pilot projects with utilities to validate the robots in various conditions. While population growth is stressing our water infrastructure, WatchTower is on a mission to secure clean water for 1 billion more population, by fixing one leak a time.

Awards

2018 Environmental Media Association Future Innovator Award Forbes 30 Under 30 Class of 2018 2017 Boston HUBweek Demo Day Grand Prize 2017 Ocean Exchange BIG Pitch Award 2017 Booz Allen Hamilton Data Analytics Award 2017 MIT Water Innovation Prize 2017 Infymaker Award