A future internet of drones could improve safety by taking much of the human element out of construction sites and relying on microchips, Jon Herbert reports.

Introduction

With drones now seen regularly over UK construction sites, it is not uncommon for companies to warn their employees of survey flights in advance to avoid the impression of being spied upon. Not only drone technology, but also the new human-machine relationship is evolving. The one certainty is that flying robots are here to stay. They are affecting everyone working on the ground below.

Drones are flown to regular routines and often operated by specialist unmanned aerial vehicle (UAV) companies (because of third-party liability concerns). They are quickly becoming an established, low-cost efficient tool for surveying sites from vantage points only offered until recently by more-costly helicopters or manned aircraft flights.

They are ideally suited for recording what is happening below, relaying live pictures, or bringing back revealing photographs and thermal images — yet one of the key drivers behind the near-forensic information that many commercial drones can now provide is site safety.

There are three safety considerations pertaining to drone flights above construction sites. One concerns the airworthiness and operation of the machines themselves. However, the other two relate to the immediate and long-term benefits that drones currently and in the future will bring.

In the first instance, what happens if a drone’s controls are hacked, mid-air collisions occur in increasingly crowded airspace, or power failures force a machine to the ground? Better technology seems to be the most promising answer.

More positively, and of particular importance to building companies, drones are already producing progress reports and visual hazard warnings — from structures about to fail, to poor workmanship and safety infringements — which an eye in the sky offers like no other.

However, the third and more futuristic role that drones can play in ensuring a safe working environment comes from the unique attributes of the craft themselves.

Their size, hovering ability, slow manoeuvrability speeds and instrument-carrying capacity allow drones to reach tight, high and awkward places as an alternative to bringing in time-consuming access equipment use, suspending operations, or simply having to live with employee’s risks.

Many sites are now using drones as a standard quality tool that also bring back data of interest to health and safety managers.

An above-site revolution

Drones’ capabilities on construction sites can reach still further. Extensive research around the world is looking into technologies that can not only increase the lifting power and duration of individual drones but also co-ordinating whole fleets of small aerial robots choreographed to work together in lifting and moving loads much heavier than themselves.

The idea of drones working together like “termites” one after the other, relaying building materials and components to exactly the right place at exactly the right time to create large structures with precision is also being explored.

Going further still, researchers are looking at the very real possibilities of connecting drones with 3D technology to create components accurately in situ.

Drones coupled with the industrialised construction manufacturing processes that some large UK contractors are now developing to fabricate building components off site in clean, dry and controlled conditions away from the weather, could also become commonplace on future projects.

However, there are logistical hurdles to cross before that becomes a reality.

Demise of feet on the ground

As automation makes the person in a yellow hi-vis jacket more of an endangered species on modern construction sites, the drone is an obvious alternative.

Typically travelling at 35mph–40mph across a 160-acre site for perhaps 40 minutes on one battery charge, drones can remove many risks at the push of a joystick.

The construction company, Costain, is already using drones that can be equipped with hi-resolution cameras, plus thermal-imaging, light-detecting and range-finding devices to protect workers.

Costain says that its main drivers are taking people out of hazardous environments and understanding where more efficient drones of the future with greater payload capacities will open up new opportunities.

However, because of the swift pace at which drone technology is advancing, plus liability and regulatory issues, the company has chosen to work with expert UAV-technology leaders.

The USA currently has an odd situation whereby hobby drones are permitted to fly legally, but commercial ones are not. In the UK’s crowded skies, changes and clarifications in the law are also expected.

Initiatives worldwide

This is still scratching the surface of what drones are expected to be able to do in the future.

Japan is already combining drones with other on-site equipment automation. As a nation with an ageing population and a limited young workforce, building infrastructure is a challenge.

In 2013, Komatsu broke the ice with its launch of the D61PXi-23 intelligent Machine Control bulldozers which, it says, can not only achieve high precision during construction operations but also shorten site work times by streamlining essential activities before and after the construction phase.

Komatsu’s SMARTCONSTRUCTION packages use IT, including drones, to connect all work-site information between people, machines and the ground. Its KomConnect software is a cloud-based platform capable of storing, analysing, running simulations and producing proposals based on accumulated data that can be accessed through the internet.

Most construction contracts begin with a topographic survey. Conventionally, a pair of surveyors can survey a few hundred data points some 10–20m apart in a day. The resulting 2D drawings needed for 3D work can introduce mistakes.

Komatsu has linked up with Californian survey-drone specialist, Skycatch. Under good conditions, drones can survey a site in 15 minutes, taking millions of recording only centimetres apart. Laser scans can add 3D precision, says Skycatch.

That data is then used to instruct ground equipment including driverless bulldozers. Komatsu already operates some 350 intelligent bits of kit on circa 800 sites in Japan.

Maintenance is often a follow-on priority when construction is over. Because all data is retained on the KomConnect system, this can be used as a benchmark and guide.

Japan, like Italy, is a seismically active area prone to human disasters. Stored data from drone flights can potentially help in rescue attempts and reconstruction.

Skycatch says that maps come to life using its drone “dashboard” information, allowing overlays to be imposed over plans, volumetric measurements made and data to be shared easily. The company believes that this will result in a “much better safety record”.

Komatsu describes its project as the “tailwind of IoT”. It is not alone in the integrated drone technology market. Caterpillar recently announced a partnership with the San Francisco-based drone analytics company, Redbird.

Siemens is another company experimenting with drones. It has gathered aerial information in Austria from one of Europe’s largest urban development sites whereby, with image processing software, it is able to visualise energy losses across an entire neighbourhood. When presented as thermal images, individual buildings can now be pinpointed for energy efficiency improvements.

From polystyrene blocks to skyscrapers

In 2011, ETH Zürich’s Institute for Dynamic Systems and Control demonstrated how a 6m-high tower made from 1500 polystyrene bricks could be built by a fleet of flying robots putting pieces in place one at a time guided purely by mathematical algorithms working to a digital design.

As off-site manufacturing becomes more common in construction, this is one direction in which the future might go. However, there are problems to be overcome in giving drones not only a passive but an active role.

One development area is the interaction between people and drones; rather than being controlled solely by a remote pilot, the aim is to fly machines that can be pushed out of the way easily if they interfere with people in a shared workspace.

The University of Pennsylvania has also shown how a fleet of drone robots flying in tight formation can maintain a close pattern — even during complex figure of eight rolls — through hundreds of commands per second.

The importance is in enabling many individual drones, each with limited lifting power, to act in unison and carry much heavier loads. The research team’s inspiration comes from studying the collective transport skills of ants. In theory, hundreds of drones could work side by side to achieve mighty tasks.

Other approaches do not rely on external controls, but foresee drones that react instantly to their neighbour’s behaviour in the same way that starlings flock. Other research based on bird flight is also being carried out to see how small units can recover quickly in turbulent environments — gusty winds.

Platoons of small robots are said to be more manoeuvrable than larger machines in tight corners. At present, the carrying capacity of single drones, largely limited by battery size, is in the region of 35–45lbs.

The reality is that there could be serious limitation to a future drone capabilities; the economic case needs to be proved too.

Yet, replacing polystyrene blocks with an airborne 3D-printer capable of building full-sized skyscrapers efficiently is also being discussed seriously.

In 1903, the Wright Brothers’ inaugural powered flight at North Carolina’s Kitty Hawk beach seemed to defy reality.

Watch this air space!

Last reviewed 28 September 2016