A self-sustaining and non-intrusive wireless smart water meter

Introduction

This project investigated options in collaboration with Northumbrian Water Group (NWG) to develop a non-intrusive intelligent water meter for use in water flow measurement and leakage detection with the ultimate aim of improving water utilisation and reducing water leakage in water networks. The key outcome was the development of a prototype ultrasonic IoT water flow sensor meter and successful operational performance in a simulated real-world environment test bed demonstrator.

This also led to discussions on developing a system powered by energy harvesting, which will be addressed in a follow-up EPSRC IAA project which has recently been awarded.

Project aims

This Pitch-In project focused on using an ultrasonic IoT water-flow meter prototype for water flow measurement and leakage detection in pipes as part of NWG main research activities. While NWG were aware of the benefits of IoT, they were not confident in committing to this type of project without technical support from Pitch-In.

Additionally, there was also a corresponding financial risk at the implementation stage. Therefore, NWG gives priority to ‘safer’, less risky projects with a more straightforward pathway to deployment when allocated funding from their RD&D budgets. This Pitch-In project facilitated the de-risking of the introduction of IoT solutions for predictive leakage detection.

What was done?

Since access to NWG test beds was not possible due to Covid, a small test rig was built at the university using pipes of different diameters (15mm and 22mm diameter) and materials (plastic, copper and chrome) in order to simulate the range of pipes used in real–world conditions (see figure 1 below).

A non-intrusive ultrasonic sensor system for water flow rate Q measurement was designed based on delta-time-of-flight ΔToF calculations, and its performance was evaluated against conventional intrusive water meters.

The key outcomes of this work were :

• Development of the measurement methodology for ΔToF and Q with non-intrusive ultrasonic sensors, and the evaluation of different methods for ΔToF calculation.

• System design for upstream (UPS) and downstream (DNS) signals acquisition, ΔToF calculation, and flow estimation.

• Experimental characterisation in terms of precision and sensitivity to determine the optimal ΔToF method for selecting the best sensor and housing setting, which is operable even under the worst deployment conditions.

We also designed our own primary graphical user interface (GUI) to view ΔToF and Q.

Results

This work demonstrates the use of a a ΔToF-based non-intrusive ultrasonic sensor system for water flow rate measurement with reduced deployment and maintenance costs compared to conventional intrusive water meters. We carried out extensive tests for precision and sensitivity characterisation determining the optimal ΔToF-based method with the lowest memory and computation requirements.

The selected ∆ToF method for the employed platform was then used to determine the best sensor and housing setting that is operable even under the worst-case deployment scenario. The empirical findings demonstrated that is was possible to achieve a level of precision up to ±5.7% with good sensitivity. This confirms the potential of replacing conventional intrusive methods with the proposed non-intrusive solution at the household level.

Impact

This project laid the foundations for further investigations and also provided a framework for further engagement with NWG, which came about directly because of Pitch-In. This also led to support for NWG from the recently awarded EPSRC IAA project.

Lessons learned

I believe that the knowledge shared between my group and NWG was the main achievement of this project, and in this sense, both parties benefited from our collaboration. Additionally, being a new lecturer, this project helped me understand better the needs of companies in North East England, where collaboration with universities can contribute significantly to consolidating and strengthening their position in highly competitive international markets.

Finally, the project helped me create a foundation for my future research work and industrial collaborative projects. It also helped me a lot with current EPSRC New Investigator Award proposal.

The primary issue was related to accessing the NWG sites restricted by COVID-19. Therefore, we could not test our ultrasonic sensor system at NWG sites. If we had known that before, we would have set up working policies to facilitate sites visits and ensure the success of in-field activities.

Fortunately, the PDRA was not hampered by having to work at the MicroSystems Lab at the university rather than at NWG facilities; this is encouraging since because of Covid, this situation is likely to continue to be in place for the entire duration of the follow-on EPSRC IAA project.

I believe it would have been helpful to have two research associates rather than one on this project; one focused on the measurement aspects and the other on the energy harvesting and communication capabilities. Having only one person didn’t enable us to achieve all the ambitious outcomes we had planned when the project was conceived. However, the follow-up EPSRC IAA project should enable us to achieve all of our planned objectives.

What has Pitch-In done for you?

This project was essential to help establish my research group. I am a new lecturer at Newcastle, and Pitch-In gave me a significant opportunity to work with an important company and lay the foundations for future research and collaborative projects with the industry.

Project lead

Dr Domenico Balsamo – Newcastle University

Project partners

Northumbrian Water Group

Energy

Building IoT capacity and collaborations

Derisking IoT adoption

Developing IoT and ensuring fitness for purpose