Robotics and Automation for Water Exploration and Leak Prevention

Water is one of the essential substances that endeavors for people to investigate and explore are never sufficient. About 71% of the earth is covered by water, mostly in seas and oceans. Observation of marine life and exploration of unknown environments with minimal disturbance can help us better understand the habitat we are living in. Moreover, we, humans, even can’t live without clean water. Thus, improving the working condition and health of the water supply pipe system is the underlying task humans have to face. One problem is in open water, while the other is in a confined pipe space. But these two researches are quite relevant inherently and they both outline our contributions in soft materials, embedded instrumentation, control theory, and design methodologies.

A. Robotic technologies for smart pipes, in-pipe inspection and repairs

A.1 Specific Application

The world has a major issue with the basis of life, water. By 2025, the United Nations predicts that nearly two billion people will be living in countries or regions with absolute water scarcity. Furthermore, there are added stresses. They include (i) effects of climate change, (ii) rising demand for water by many communities,(iii) water pipe leakage, (iv) inefficient water management, and (v) inefficient water utilization. Around the world, about 25-30% of fresh and clean water is leaked into the ground annually during distribution. In developing countries, water loss rates can be more than 40%. In addition, results of such water leaks can result in property damage, caving of streets and foundations, and water contamination. Inefficiency of water management amplifies losses through pipe leakages. Thus, reducing the non-revenue water to an acceptable level is crucial. Different sectors rely on water and are significantly affected by these issues. They include energy utility, agriculture, commercial, manufacturing industries in addition to residential. Such pipe leakage problems happen also in the gas distribution industry. For example, the state of Massachusetts in the US, loses more than 18% of the distributed natural gas due to the 3000 leaks that take place every year. Therefore, reliable and effective technologies must be developed and deployed to ensure the sustainability of water supply.

A.2 Innovative, outstanding and essential

Our efforts have focused on the development of advanced robotic technologies for pipes, pipe inspection and repairs. Our approach targets two objectives: (i) development of smart pipes and (ii) in-pipe robots. Smart pipes are pipes that are instrumented, equipped with computing and communication capabilities. They gather and transmit information that includes continuous health monitoring and pipe integrity, product flow inside the pipe, the exact location of needed inspection, maintenance or repair, etc. Innovative multi-layer sensors with finely tuned material properties within each layer are developed to increase the signal-to-noise ratio. A novel energy harvester adopting magnetohydrodynamics (MHD) is developed to power low-power sensor nodes. In-pipe robots, on the other hand, are specialized robots designed to maneuver inside a pipe and conduct various tasks. This is different from diagnosing or repairing water distribution pipes from outside of the pipe. State-of-the-art rehabilitation techniques require the use of heavy machinery and human labor. Such practices are time-consuming, expensive, and inefficient, requiring service interruption. Several advantages are thus inherent to in-pipe robots. For example, the internal surface of pipes is generally more ‘informative’ than the external surface. Corrosion, the number one reason for pipe outbreaks, takes place more frequently inside the pipes than outside. Detecting or analyzing the by-product of pipe corrosion, such as tubercles, with an in-pipe robot, can lead to more certain indicators of a pipe defect, even before the defect actually takes place. We successfully developed both passive and active robots for diversified tasks in the pipe. The active robots we designed to feature outperforming maneuverability, which is superior within the confined pipe space.

A.3 Specific application: describe its tangible results and reasons for its significance

A series of in-pipe robotic solutions were developed. The development of such specialized robots and their associated technologies started in 2008. These include an in-pipe locomotion robot, an in-pipe inspection robot, an in-pipe rehabilitation robot, an in-pipe energy harvester, on-board pipe inspection sensors, underground communication networks, and underground path planning schemes of robot swarms. The inspection robot, rehabilitation robot, and energy harvester are three outstanding examples that present tangible advancements in our research. In brief, our customized pipe-profile sensor and off-line localization algorithms, the inspection robot portrays the in-pipe profile accurately as it moves along the pipe, including both pipe obstructions and the presence of leaks. Operators can then decide if a pipe segment requires an imminent repair or if the condition falls under operating standards. With this predictive capability, the water department is able to perform pipe rehabilitation before damage takes place, preventing major expenses, service disruptions and, and more importantly, ensuring the safety and health of citizens. Upon successful identification of(potential) pipe-related hazards, the next step is to rehabilitate the defect area. Consumer health and safety are of prime importance.

For example, here is an in-pipe robot that rehabilitates the pipe, contains the contamination while maintaining water service. Maintaining water service and water quality is desirable by customers and water departments. Manual pipe rehabilitation is also an abundant source for pipeline contamination, with corrosion in particular. The MRL rehabilitation robot aims at ameliorating pollution generated from the rehabilitation operation. It features a specialized robot configuration and a soft end effector to contain as much operational waste as possible. The advantage is obvious. By accessing the defect location from the inside, operators no longer have to conduct excessive digging and interrupt service. In addition, rehabilitation operations are far more efficient. In the case of traditional rehabilitation, the entire pipe section has to be replaced, even when the defect area is small. Alternatively, the in-pipe rehabilitation robot can localize the operation in this minimal area. Furthermore, robotic rehabilitation avoids the necessity to open-cut the pipe segment. This provides remarkable potentials that rehabilitation could be done even without shutting down the water distribution service.

Designing and instrumenting auxiliary devices for in-pipe operation is a critical step towards the entire in-pipe industry. One outstanding example is our in-pipe energy harvester. We developed magnetohydrodynamics (MHD)based energy harvesters for low-power instrumentation. This innovative solution uses the water flow in the pipe to generate electrical power. Unlike traditional energy harvesters utilizing principles of electromagnetics, piezoelectricity, and solar energy conversion, the MHD energy harvester features a dramatic increase in robustness. This is essential in this application because of the ultra-long lifetime requirement of the pipe system. After careful analysis and design, our prototype MHD energy harvester demonstrates the potential to meet the power requirements of a sensor node with microcontrollers, sensors, communication, and data storage. This development provides a new perspective on energy harvesting and great confidence in self-contained instrumentation in the next generation of smart pipes.

Some other featured works are also noteworthy as important parts for the whole system to work. Sensing the robots location via GPS or remote sensors requires greater power and relies on certain ground properties. Thus we set out to localize the robot using only the onboard sensors which are an IMU, gyro, and the leak sensors. Through pipe joint measurement and the extended Kalman filter simulations show the tracking error is about 0.5% of the total distance of the robotic inspection. To better differentiate leaks from pipe joints and obstacles, sensors were arranged in a particular way to decouple the four deformation modes of the material: uniaxial tension, bending, compressive pressure, and torsion.

A.4 Playing an important role in human life

These developments have an important role in human life. Around 700 million people are suffering from water scarcity. The problem affects 43 counties from every continent on the earth. However, water scarcity is getting worse and worse. By 2025, absolute water scarcity will happen in the counties and regions where 1.8 billion people will be living. Two third of the global population will need to face stressed water conditions. And this ratio will increase to half by 2030. Even in regions with sufficient water supply, water quality is still a big concern. WHO reported that more than 3.4 million people are killed by water-related diseases around the world, making it the leading cause of disease and death. The smart pipes and in-pipe robots developed by us can effectively ameliorate the problem by monitoring and repairing the leak to make the utmost of the limited clean water supply, and monitoring water contamination in multiple forms to increase the water quality and control disease spread. Even in countries with sufficient and hygienic water supply, our research can further improve the efficiency of water utilization, boosting the development of industrial production and improvement of human life by lowering the cost of water supply.

B. Marine Robotics

B.1 Specific Application: Monitoring and predicting ocean health and marine life is crucial to the health of our planet. Conserving and renewing marine life to ensure a healthier planet.

As the saying goes Ocean health is our health. Covering more than 70% of the surface of our planet, oceans are the goldmines of natural resources. As technology advances, so does our step towards deep water. Underwater operations, such as oil well exploration, oil-spill monitoring, tactical reconnaissance involve strategic competitions between governments. With hydrologic monitoring of the ocean, such as the salinity, water temperature and dissolved oxygen, scientists are able to make predictions of the future states of various species. On the other hand, keeping track of the biological information of aqua-lives is also an accurate probe for scientists to observe the health of the ocean, or even, the health of our planet. [Ocean health to our health]

Even more resourceful and inspirational than the ocean is natural habitats in the ocean. For example, blue-fin tuna can reach a speed of ~74km/h, an extremely high speed even compared to modern ships that are proposed by steam or nuclear engines. The stamina of Atlantic salmon allows them to travel more than 10,000km before coming back home. How the naturally-evolved aqua-lives achieve such impressive engineering performances are of significant research value. To study the natural state of aqua-lives and protect our precious ocean, we, as observers, have to blend into the background. Looking and swimming like a fish is our solution.

B.2 Innovative, outstanding and essential

Our work focused on the development of biomimetic robots for monitoring ocean health and marine life in their natural state. The MRL is the first to apply and formalize the basic principles of the underactuated soft body approach to fish-like robots. The approach relies on two principles: using soft bodies instead of traditional stiff mechanisms, and allowing passive mechanism dynamics to achieve target motions. With analytical modeling of desired swimming motion and combining it with the viscoelastic dynamics of the soft body in fluid, we can optimize the geometrical and material properties, such as the modulus of soft material and viscosity distribution of the fish body, and prescribe the actuation distribution, including actuator number, locations, magnitude, and frequency. Our design methodology is universal. We successfully applied the design to carangiform and thunniform-like bodies and later transferred to much more complex body forms such as batoid-like robots, like stingrays, and salamander bodies. Our robot takes full advantage of soft materials and swimming posture of fish, allowing us to significantly reduce the mechanical complexity of the robot while generating a more natural motion than previously proposed robots. Our research work also pioneered in characterization of and fabrication with soft materials like silicone rubber.

B.3 Specific application

A diversity of robotic fish were developed and field-tested. With our universal design methodology described above, we were able to propose and implement soft robotic fish of various body shapes. In one of our research articles, we detailed the development of a carangiform fish. Despite the kinematic and dynamic equations, we also set up a constrained optimization problem, such as minimizing the number of actuators, actuation amplitude or energy consumption. The finalized design is in a form of servo-actuated rigid plate, embodied in a viscoelastic body. To handle the fabrication of this unique design, we invented a sequential molding practice. The prototyped soft robotic fish was experimented in a laboratory environment. Our data acquisition system tracks the trajectories of multiple points on the robot’s body, collects the thrust, velocity, and visualizes the vortex flow at the vicinity of the fish. Additionally, we generalize the work to fish with even more complex geometries. One of our famous works is the stingray prototype. We conducted a field test with the stingray robot in Singapore.

B.4 Playing an important role in human life

These developments have an important role in human life. Our development in bio-inspired soft robotic fish plays an important role in human life. Scientists and engineers can now study and observe marine lives more intimately and quietly than ever before. Potentially, with our naturally-motioned robots, we will be able to manipulate the behavior of marine lives, or even perform in a leadership role. Such applications include steering fish away from environmental disaster, or balancing regional populations of various species. From an engineering point of view, the underactuated natural and its related control, fabrication, and mechanical design are inspirational to related researches. The efficient propulsion methodology of fish and unique usage of soft material are also heuristics to other marine robot locomotions or under-water vehicle designs. It motivated one of the MRL in-pipe locomotion robots in a later study.

C. Influence of the work:

C.1 important scientific contributions and advancement of knowledge

Our work has resulted in important scientific contributions. As a result, in the journey of this project till now, we have published 50 papers and disclosed 18 patents. The papers and patents range from sensor design and analysis, robot design, localization, communication, network management, and system integration. We also composed one book comprehensively covering not only the locomotion, actuation, design, soft material, and control, but also robotic fish collaboration and robot fish in animal behavioral studies. All these publications contribute cutting edge knowledge to academia and industry and provide priceless experience for enthusiasts working on soft materials, robotics, mechatronics, fluid-structure-interaction, and artificial intelligence. Dr. You Wu, the main developer of the leak detection soft robot, is honored with the following awards:

1) 2017 MIT Water Innovation Prize, this a startup competition focused on water innovation that awards up to $30K in innovation grants annually to student-led teams.
2) 2017 Infy maker Award by Infosys Foundation, Infy Maker Awards is a competition hosted by Infosys Foundation USA.
Environmental Media Association, 2018, The Environmental Media Association (EMA) is dedicated to the mission of promoting environmental progress and bring the planet’s most pressing issues to the forefront.
3) Future Innovator Award, 2018 James Dyson Award, and many others.

4) Forbes 30 Under 30, one of four MIT students in 2018 to receive this title even before his graduation.

In addition to the awards, our in-pipe leak detection robots were featured on the Business Insider, Quartz, the MIT News for twice, and several other reputational press in the US. Our marine robot is reported by the discovery channel, CNN, and MIT news.

Our research has advanced the frontiers of knowledge. Besides the key technologies we developed during the journey, we proposed several methodologies for sensors, soft material modelings, design, robotics, and several other fields. With these methodologies and experience, we promote our research faster and faster. For example, in the development of the marine robot, we identified and summarized a five-step design methodology for soft robotic fish. And in most of our researches, we combine theoretical analysis, modeling, numerical simulation, fast prototyping, and testing.

C.2 Our work had a great impact

After successful development in the lab phase, we gradually ramped up our field test, industrial collaboration, and commercialization to pursue a greater impact. We first collaborated with Singapore on the robot fish. Later, we collaborated with Saudi Arabia to perform the test of our leak detection soft robot in a well-established above-ground pipe system. The results are promising that even premature leaks with a small flow volume can be distinguished and trigger the alarm. After that, we were invited by the water authorities of Cambridge, Virginia, Brazil, and the UK to perform field tests in real pipe systems that supply water to households. The results are satisfying. Several leaks were detected successfully, and the water authorities avoided the huge economic loss and potential service interruption. With these field tests, the adaptability of the robot to various working conditions, pipe materials, pipe sizes, and flow volumes is demonstrated. With the experience of the successful field tests, a startup called watchtower is launched by Dr. You Wu, who graduated from MRL.

When working on the problem, we bear in mind that generality is also a top priority besides efficacy. Most principles we investigate and dive into are generic. Thus the technologies and breakthrough we contributed can also be applied to some other industries with similar problems. For example, Massachusetts in the US loses about $100M per year due to the natural gas leak. The petrochemical companies, which rely heavily on pipe systems to deliver the material and products, also encounter the similar problems of a pipe leak, pipe burst, and pipe corrosion. The leak detection sensors sense the pressure gradient around the leaks, which is a common phenomenon for fluid with high pressure inside an enclosed space. The seal and machinery cleaning mechanisms are also generic for hard surfaces. Thus adopting these technologies in other industries is a pushover. The generic solutions to our research make our innovation much more impactful.

Publications

2019

15.

You Wu; Elizabeth Mittmann; Crystal Winston; Kamal Youcef-Toumi

A Practical Minimalism Approach to In-pipe Robot Localization Proceedings Article

In: 2019 American Control Conference (ACC), pp. 3180-3187, IEEE IEEE, 2019, ISBN: 978-1-5386-7926-5.

Robotics and Automation for Water Exploration and Leak Prevention

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