Not all drones are created equal: Where should we be investing?

By Dario Valenza, Founder & CTO, Carbonix - High Performance Systems in Advanced Composites

‘Drone’ is now a prominent buzzword in the tech world. We read daily about new uses, across a steadily growing range of industries. As would-be players battle to claim their piece of the ‘early adopter’ drone pie, it’s important to understand that not all drones are created equal. 

To be more precise, ‘drone’ is a generic term, perhaps like ‘personal computer’. All drones are vehicles to position payloads in places that are difficult, dangerous, or expensive for humans to access. Payloads can be any of a range of useful sensors, including cameras, electromagnetic (beyond the visual spectrum), magnetic, acoustic, seismic, scanning devices... Payloads can also take the form of care packages, medical supplies, signalling equipment. The list is varied and growing. 

It is growing partly because of the ingenuity of specialists in different industries considering remotely piloted vehicles to do jobs in new ways. And partly because key technologies are becoming more powerful and economical, whilst also getting smaller and nimbler.

Major investments and advancements have been made in core and peripheral technology to bring drones to our front door, to make them smaller, lighter, and more suited to everyday needs. This effort has benefited enormously from advances in consumer electronics, energy storage, and precisely modulated wireless communication. 

It is worth considering that compact processors and sensors, very small digital cameras, and efficient batteries, have all drawn greatly from the ubiquity of smartphones. Think, for example, how protruding aerials have disappeared, and how your phone knows whether you are holding it in portrait or landscape orientation (via tiny solid-state sensors). The app ecosystem has also made vast resources and a reliable skill set available for software development.

Today, compact payloads can be flown around economically and reliably, largely as a result of ‘convenience technology’ - enormous economies in electronics and energy storage. 

Understanding the background ecosystem lets us see why most people think of a small multirotor when they hear the word ‘drone’. The low hanging fruit has been a machine that takes off vertically, can hover near a target, and then land at the starting point laden with valuable data. At the other extreme, people may think of large mysterious glider-like military machines that circle over combat zones gathering grainy images of suspect enemies. Now you see how the catch-all designation of ‘drone’ describes a vast gamut of machinery.

The space in between - commercial fixed-wing drones - is wide and ripe for development. It is where investment should and will be directed in the near future. The reason is inescapable physics: Multirotors (quadcopters, hexacopters and the like), are suited to short duration flights in relatively still air. They excel where short periods of hovering are required and frequent landings for new batteries are not a hindrance to the mission.

However, more and more applications call for long endurance – flying continuously over long distances - whether point-to point, loitering, or covering a grid for search and rescue or mapping purposes.

Fixed-wing drones expend less energy for a given mass to achieve the same range. Therefore, they can fly further and longer on the same battery, hence fixed-wing being preferred for military reconnaissance.

The limiting factor today is the efficiency of the airframe. This has two major components: Aerodynamic drag and structural weight. The two are somewhat interlinked because using stronger, lighter materials can enable thinner structural members, reducing aerodynamic drag. A proper understanding of the aerodynamic behaviour of loaded structures is necessary to know how to optimise performance. 

At Carbonix we specialise in aeroelastic structures, using advanced composite materials to create streamlined, efficient airframes, with a view to achieving unprecedented range, reliably.

Carbonix Volanti VTOL Drone

A fixed-wing drone is usually composed of a unitary streamlined structure designed to travel longer distances with specifically designed aerodynamics. This makes them suitable for missions such as aerial surveying where a large area must be covered.

Copter v Fixed Winged Drones

From the chart above it can be seen that the optimum configuration for long-range missions in the absence of a prepared runway is one that combines the advantages of both the multirotor and the fixed wing aircraft.

Industry Comparison

Advancements in fixed-wing drone technology are about creating lighter structures that can carry greater weight for extended periods of time, with a focus on reliability and the ability to withstand adverse weather conditions. Major investments are occurring in this space and will be growing rapidly. 

As airframes scale, low-tech materials stop being suitable and structural weight becomes a serious limiting factor. Carbon fibre and related advanced composites are increasingly being used to create fixed-wing drones that overcome scaling barriers.

Efficient structures also open the door to vertical take-off and landing, increasing the versatility of fixed wing airframes.

At Carbonix our heritage in competition and our leadership in aeroelastic optimisation enable us to lead the way in making efficient airframes accessible to extend range economically.

So, as we all scramble to align our inner geek with the commercial realities of determining how and where to invest money in drone technology and testing, executives must understand how drones can truly help their bottom line, and which type of drone will ultimately achieve the best result for their business.