#Robotic Automation
Autopilot Systems Equip Drones With Advanced Capabilities
In September 2014, NASA issued a request seeking partners to help develop a traffic management system for eventual use by the Federal Aviation Administration (FAA) that applies to unmanned aerial vehicles (UAVs) operating in Class G airspace (ground level to 500 feet)
One participating company is Airware, a firm that produces hardware, software and cloud services for commercial UAVs. NASA expects to be able to operate and test a wide range of aircraft, custom software and components using Airware’s autopilot system. The company is one of many in the growing field of technology solutions for UAVs, commonly referred to as drones.
Airware bills its system as an aerial information platform for non-military drones. Earlier UAV models were designed for one specific application or task. Airware’s platform allows customers to customize commercial drones for a variety of applications (the company neither makes nor sells the drones themselves). The software includes autonomous flight control, ground control software and cloud services. It’s a plug-and-play approach that works with Airware-compatible airframes, sensors and payloads.
The company calls its product the first operating system for UAVs. The physical component central to Airware’s system is a box that runs Linux and is based on a Cortex ARM processor. This little red box is responsible for flying the drones safely and for collecting flight data. After an Airware-equipped drone collects data, the system pushes the data to the cloud where users can aggregate and analyze the information.
AirwareAirware’s system uses a message-based API that allows developers to make their own applications. These applications run on the autopilot system and communicate with sensors and other parts of the drone’s payload. Airware also developed drivers for different components that can be integrated into its software system.
Drone Market Growth
Companies such as Airware stand to reap some of the benefits of the growing interest in UAVs. According to IHS UAV analyst Derrick Maple, the global market for UAVs – including defense, security and aerospace applications – will grow over the next 10 years to nearly $81 billion. He says the autopilot systems market for UAVs will be responsible for about 2% of the total market, or about $1.5 billion, over that time period. This growth is likely to be addressed by a growing number of companies as the miniaturization of electronics/sensors continues and becomes more available globally.
Factors such as high power density batteries, less expensive hardware, low-power and long-range micro radio devices, and more powerful microprocessors and motors mean that UAVs are beginning to make more sense for a variety of applications. Non-military drones (some of which outside of the U.S. use Airware’s system) are used for mapping, wildlife tracking, search and rescue and architectural engineering, among other uses. Many of these UAVs are small and lightweight and fly close to the ground, which can be a problem. Low-elevation flying makes it easier for UAVs to crash, meaning they must come equipped with a reliable autopilot system.
A recent article in the International Journal of Control, Automation, and Systems defines a UAV autopilot system as a close-loop control system with two different parts: a state observer and a controller, which provide “state estimation and control inputs generation based on the reference paths and the current states.” State observers make up a UAV autopilot’s “micro inertial guidance system including gyro, acceleration and magnetic sensors.” Some UAV autopilot state observers also include infrared or vision-based devices. The controller consists of an on-board processor that collects data from sensors (state observers) such as GPS receivers that can be used for control purposes.
Flying Sensor Platforms
In essence, UAVs are mobile platforms that house a variety of sensors to observe the aircraft’s state in precise detail. The GPS waypoints and autopilot system tracks include other tasks as well: pitch attitude hold, altitude, speed, takeoff and landing, turn coordination and roll-angle hold, among others.
UAV hardware and component manufacturers operate in a crowded field. According to Jonathan Downey, Airware’s CEO and founder, more than 600 companies currently make UAV hardware. He says that Airware’s operating system is akin to DOS for drones and will benefit both drone manufacturing companies as well as third-party peripherals companies that make items like cameras and sensors.
Downey says that hobbyist-built (generally open source) autopilots aren’t reliable enough or necessarily safe enough for commercial use. At the other end of the spectrum, military-grade autopilots are expensive and available only to a select clientele. Airware’s system is intended to fit between the hobbyist and military-grade solutions while providing “enterprise-grade reliability” and safety.
IHS’ Maple, however, notes a possible benefit to open source. While Airware’s concept gives the system designer a "flexible solution with a lot of the design outsourced effectively," he says it does "tie them down somewhat compared to an open source solution.”
Miniturization
While there are many open-source autopilots, one system, Lisa/S, claims to be the world’s smallest autopilot system for drones, giving it potential uses beyond other offerings. The idea is to make UAVs light and small enough to fit into difficult crevices or dangerous places: think of a fire department sending drones first into a burning building before humans follow. The Lisa/S autopilot measures two centimeters square, and weighs in at less than three grams.
DelftBart Remes, the Lisa/S project manager at the Micro Aerial Vehicle Laboratory at TU Delft in the Netherlands, says the engineering design team programmed new software known as Superbitrf that keeps the autopilot connected to a ground station and a normal RC transmitter at the same time. According to a news release, “this combination of functions made it possible to miniaturize the autopilot… [which allows] a micro aerial vehicle (MAV or small UAV) to stay up in the air longer and carry heavier cameras and sensors.”
Lisa/S uses Paparazzi open source hardware and software. Its hardware is provided by 1 Bit Squared, a company that designs open source hardware and software for UAVs for personal use. The company sells the Lisa/S autopilot processor along with the required cable, adapter, antenna and programmer. Unlike Airware, however, Lisa/S does not come pre-programmed.
Where Airware’s system is geared towards commercial users, Lisa/S seems to fit a variety of uses ranging from hobbyist to commercial to first responders. Given that Lisa/S is mostly available off the shelf, it may prove a more commercially viable option than many open source options given the reduced need for building and modification.
Market in Waiting
The United States largely remains a market in waiting. Until the FAA develops regulations for UAVs in American airspace, it will be difficult to make fleets of commercial UAVs available. Additionally, according to Maple, engineers will need to know about the existing manned aircraft operating space and related regulatory developments, in addition to the myriad technical aspects of the UAVs themselves and related autopilot systems.
"In short," he says, engineers will need to know "how the solution will be able to operate safely within this complex environment.”
