The DroneBox: adaptable mapping solution on all Hélicéo products
The journalist Nick Flaherty has written a four-page article outlining the mapping solution designed by Hélicéo: the DroneBox. You can read it in the February / March edition of Unmanned Systems Technology magazine. We invite you to discover a part of this editorial.
A modular mapping solution for a range of UAVs
French company Hélicéo has developped a technology platform that condenses 70% of the operation of an unmanned craft into a single unit. This has allowed it to provide a wide range of vehicles with a common design, from rotor and fixed-wing craft to VTOL and even marine systems. The company is an aerial, ground and aquatic drone manufacturer providing mapping services for the world of geomatics. It has therefore built what it calls the DroneBox, to minimise the amount of additional development required to deploy a new unmanned platform. The DroneBox combines navigation and control systems, and allows Hélicéo to provide products and applications ranging from terrestrial survey through bathymetry to aerial survey.
One of the core platforms is the FoxyPro. This is a VTOL system that combines a vertical take-off rotor with fixed-wing operation. It has a maximum load capacity of 2 Kg and has an hour of in-flight battery life, allowing it to scan up to 300 ha (741 acres) in a single mission.
A modular system offers advantages for the quick and simple construction of a range of different unmanned platforms. The DroneBox is made of ABS plastic, which is a “neutral” material that will not interfere with radio communications. Like all Hélicéo products, the design is carried out at the company’s headquarters. The electronics assembly is also handled internally in its workshop, along with the wiring and testing.
The features of the DroneBox
Satellite Navigation and Connectors
The DroneBox uses network RTK (Real Time Kinematics) to provide higher accuracy than GNSS satellite navigation alone. RTK makes use of a separate transmission that carries error data and corrects the GNSS data in the UAV. The GNSS and RTK systems are supplied by Trimble, whose GNSS centre is partly based in Nantes, France, close to Hélicéo’s r&d facility. The GNSS RTK antenna is also customised, and was designed by Hélicéo.
The choice of connector for the DroneBox was the subject of detailed research, as it is vital to the effectiveness of the whole system, says Hélicéo’s CEO Jean-François Baudet. The connector is therefore very specific and was made by US company Samtec according to Hélicéo’s specifications. It is highly resistant to vibration to prevent inadvertent disconnections.
Autopilot and Telemetry
The autopilot and flight controller were developed in France with the power supply cards developed by Hélicéo. The development required two years of R&D and the design of the autopilot was the subject of a patent. Geomatic engineers at Hélicéo developed a GNSS data processing software called HASK to increase the accuracy of GNSS data. Hélicéo has also developed a catamaran, called the FoxBathy for underwater mapping surveys in lakes, rivers, marine areas, and lagoons. </ p>
The telemetry operates in the unlicenced 450-900 kHz bands with varying power levels. The supplier varies according to the country of use to ensure the radio systems conform to local regulations. Hélicéo has developed its own radio control link for managing the RTK. Flight data is stored on a high-speed SD card.
Imaging systems and Battery power
Cameras are integrated into the drone for photography in the visible spectrum, with geo-location data from the DroneBox using the single shot trigger capability. All the data is stored on a SD card in the chosen camera. The global shutters provide distortion-free images in the red, green and blue bands for RGB colour images that when processed are aligned to all visible and non-visible bands and vegetation indices. For thermal imaging the FoxyPro also supports cameras from FLIR. It is factory-calibrated for accurate temperature measurements from an airborne perspective. Set-up is via a mobile app (Android) and built-in Bluetooth and both video and still images are recorded on an onboard microSD card.
The battery system is platform-specific. The SuperFox6 LiDAR has a mission flight time of 43 minutes while the FoxyPro, again using the DroneBox can run for an hour of autonomy. There is also a new version of FoxyPro, called the Fusion. Fully automatic under control of the DroneBox, the 6Kg craft takes off vertically, follows its flight plan, takes photos and lands vertically. This minimises the cost of operating the vehicle as well as the risk of damage. Developing all the control technology in a central unit has allowed Hélicéo to support a wide range of unmanned platforms. With a common archiving and user interface, the support requirements are reduced without compromising the operation of the system, and the technology can be extended to areas such as seaborne missions.