Sensor fusion: Its role in smarter cities and construction

Sensors improve our ability to track, measure, position, and ultimately operate pretty much anything. They help industry in enormous ways, improving building construction and maintenance, delivering public services, and even driving vehicles autonomously.

Because they are the foundation for so many intelligent things, we need sensors to be reliable. Just as humans are subject to distraction, mistakes and miscalculations, sensors experience noise that may cause them to malfunction.

This is where sensor fusion comes in. When it comes to tasks performed by humans, there are protocols in place to manage safety pitfalls or defined processes that dictate how we test and learn. As we look to augment human tasks with machines, we must enable sensors to mimic how we process information. We must teach them to react to stimuli just like we would if they are to drive our cars autonomously. Similarly, we expect a group of installed security cameras to recognise the very same things any security guard would see. Sensor fusion helps makes this a reality.

What is sensor fusion, and how does it work?

Sensor fusion combines multiple sources of information in order to provide more efficient data. Take autonomous vehicles for example. Sensor fusion brings together GNSS (satellite/location), imaging (camera), inertial measurement units, or IMUs (motion), radar (speed) and LiDAR (distance) to emulate the sensory inputs a human driver would encounter and react to. Any one sensor on its own would provide useful data. But when combined through sensor fusion, these sources of information offer a more complete, reliable view of what is happening to the vehicle at any given time.

How is sensor fusion used?

“Sensor fusion” has become one of today’s buzzwords when it comes to the new generation of super-smart sensor systems claiming to solve any task — used in autonomous cars, robotics, and even in consumer products.

There is a long history of sensor fusion. The first total stations, used in surveying, can be regarded as fused-sensor systems. And these have evolved significantly since. In fact, smart-fused sensor systems not only compensate the inabilities of single-sensors, but also enhance the capabilities of multi-sensor systems exponentially, if deeply fused.

In a smart building environment, fused sensors can easily and accurately digitise an entire construction site, providing efficiencies that help you deliver and maintain asset quality. The ability to collect, process and leverage data to its fullest potential enables intelligence at all phases of a construction project. Eventually, sensor fusion will empower more and more autonomy, enabling machines to work smarter, safer and more productively.

In smart city applications, fused sensors enable the creation of a high-fidelity digital twin. City authorities can use these 360-degree digital datasets to precisely pinpoint where services are needed and which resources to deploy.

Sensor fusion does more than improve efficiency in cities and construction, it also helps to measure the “seen” and “unseen”. For example, Hexagon has developed a new type of sensor fusion — visual positioning technology — enabled through GNSS, IMU, and image camera technology. Surveyors and other professionals like those in utilities construction and crash-scene investigation can leverage visual positioning to measure, reach, and leverage previously inaccessible or obstructed points safely and efficiently.

In addition, in some industries, such as security, Hexagon is now fusing LiDAR, visual and thermal imaging, combined with intelligence at the edge (i.e. on the sensor). This wide area of detecting an intruder in 3D was previously “unseen”. These solutions leverage sensor fusion to go beyond what was once possible.

Hexagon has always been at the forefront of real fused sensors — developing our own innovative sensors and taking fused-sensor systems to a completely new level. Together with strong edge computing on the devices, sensor fusion will continue to drive innovation for smart cities and smart buildings, construction, and infrastructure projects. More broadly, sensor fusion is a foundational element for autonomous solutions across industries that will help to increase efficiency, productivity and quality ­— using fewer resources and wasting less of what we use — enabling a more sustainable future for humanity at large.

Burkhard Boeckem

Burkhard Boeckem was named CTO for Hexagon in 2020 after serving as CTO of Hexagon Geosystems since 2015 where he was responsible for technology, innovation and product development for all of the Geosystems business units. He began his career in 2001, when he joined Leica Geosystems. As CTO of Hexagon, Boeckem drives the innovation and continued development of Hexagon’s autonomous technology vision. He has a Master of Science in Geodesy and PhD.