Drones are the most dynamic market sector in the world aerospace industry, according to a 2014 report by the market research firm, Teal Group. Estimated spending in the drone industry will nearly double over the next decade from current worldwide expenditures of $6.4 billion to $11.5 billion in 2020.
In terms of market segmentation, the report estimates the drone and UAV (Unmanned Aerial Vehicle) market today at 89 percent military and 11 percent civilian. The percentages are expected to shift to 86 percent military and 14 percent civil by 2020. As the prices of commercial and hobbyist drone aircraft fall, more civilian applications become viable. Hobbyist models today cost as little as $100 and a quad-rotor drone designed for commercial use and outfitted with high-definition video camera can be purchased for approximately $1,000. More sophisticated commercial drones can be considerably more expensive. Their surging popularity is mainly due to a very favorable cost comparison with using manned, fixed-wing aircraft to do the same job.
Real estate and construction companies are already using drones for land surveys and aerial photography. Energy companies—often on the leading edge of innovation—are using them for exploration, mapping, documentation, and field inspection. In most of today’s commercial applications, a high-definition camera is the drone’s key component. Other systems are simply a means of taking the camera aloft and making it mobile.
Any company with geographically diverse assets that extend into relatively unpopulated areas—such as utilities, farms, ranches, and telecommunications companies—can employ drones for inspection, monitoring, inventory control and applications such as crop dusting. Other markets include law enforcement, search-and-rescue, and light cargo transport to inaccessible areas.
Although the terms drone and UAV are typically used interchangeably, a distinction can be made in which the UAV is capable of autonomous flight but a drone is controlled by a pilot on the ground.
Commercial Drone Design
In contrast to military applications in which the drone more often than not is a fixed-wing aircraft that takes off from an airstrip, is powered by high-octane aircraft fuel, and can fly great distances, commercial and hobbyist drones tend to have helicopter-like designs and are battery-powered. Multiple rotors (often a four- or five-rotor system) create a potent propulsion system that does not require a runway. Another advantage of drones built for military applications is that the same rotors are used as the flight control subsystem. The rotors can be tilted to maneuver the aircraft in three dimensions.
From an engineering perspective, drones are complex systems with several mission-critical interrelated subsystems including:
• Propulsion: propellers, electrical motors, etc.
• Navigation and control: flight controllers, GPS, gyroscopes, altimeters and mission-specific sensors.
• Power: usually batteries and charging systems today, although there is plenty of room for innovation in this critical area. Wankel rotary engines are being tried, for example, because of their low vibration characteristics.
• Communication: between subsystems and ground-to-air. In most cases, drones have a remote human pilot. Autonomous UAVs for commercial use are actively being developed.
• Payload: cameras, video storage, cargo or consumable cargo such as pesticides for crop dusting.
• Chassis: landing gear and other structural components.
• Software: plays a key role in most of the hardware subsystems.
Open Source
The recent spike in commercial drone activity comes at a time when the open source community is also growing in importance. For that reason, it is likely that drone design will have a much lower penetration of proprietary operating systems, application software, and even hardware.
About a year ago, for example, the Linux Foundation—in partnership with leading technology companies—launched the open source Dronecode Project. Its goal is to provide a neutral governance structure and to coordinate funding for the resources and tools that the community needs.
Founding members include Fortune 500 companies such as Intel and Qualcomm, but membership is dominated by robotics specialists such as 3D Robotics, jDrones, Laser Navigation, SkyWard, Squadrone Systems, Walkera and Yuneec. Dronecode includes the APM/ArduPilot UAV software platform and associated code, which until 2014 had been hosted by 3D Robotics. More than 1,200 developers are working on Dronecode with more than 150 code commits a day on some projects. Examples of projects include APM/ArduPilot, Mission Planner, MAVLink and DroidPlanner.
“Open source software and collaborative development are advancing technologies in the hottest, most cutting-edge areas,” said Jim Zemlin, executive director at The Linux Foundation. “The Dronecode Project is a perfect example of this. By becoming a Linux Foundation Collaborative Project, the Dronecode community will receive the support required of a massive project right at its moment of breakthrough. The result will be even greater innovation and a common platform for drone and robotics open source projects.”
Testing
Although drones present many engineering challenges, testing is one that can potentially break a project’s development budget and create time-to-market delays. Testing is necessary to assure that the drone is safe to fly and can complete its mission with high reliability. Typically, extensive field testing is used to achieve these goals for most products. With drones, this is a daunting process because environmental conditions of a specific environment may not be repeatable. Test engineers must identify the range of operating environments and often have to travel to them for field testing.
After they identify appropriate test environments, test engineers still have to deal with local regulations, which further complicate the process. Although field testing cannot be eliminated, it turns out a significant portion can be accomplished in the laboratory. Test companies familiar with simulating test environments in the laboratory for cellular technology approval and acceptance have used their expertise to develop simulated lab testing of drones.
The RF environment is every bit as important as the physical environment because that’s what affects ground-to-air communication. Testing with a channel emulator enables engineers to create a controllable RF environment that corresponds to the link between radio controller and the drone. Testable parameters included multipath fading, drone velocity, mobility path, topography and other environmental factors.
Conclusion
Drones are making an impact in the commercial market because they can collect information—and deliver lightweight cargo—at lower expense and more safely than manned aircraft. While video transmission and photography represent the core of today’s drone applications, it’s not difficult to imagine applications that use drones to supply isolated communities with medicine or replacement parts for appliances or vehicles. In fact, two significant technology developments include the adoption of the open source paradigm while drone technology is still nascent; and, the utilization of RF channel emulation to simplify ground-to-air communication tests thereby reducing the amount of field testing.