Unmanned Systems Technology 028 | ecoSUB Robotics AUVs I ECUs focus I Space vehicles insight I AMZ Driverless gotthard I InterDrone 2019 report I ATI WAM 167-BB I Video systems focus I Aerdron HL4 Herculift

62 Show report | InterDrone 2019 propellers have been carefully selected for energy efficiency, but most important is optimising the weight. “The battery is the heaviest object on the airframe’s body. Straight Up Imaging cut weight from the hull and from all the wires and other peripherals as much as possible, to dedicate the extra empty weight to carrying a small camera for as long as possible.” Several design iterations, prototypes and multiple rounds of flight tests were carried out in order to balance and optimise the different objectives of the Endurance’s development programme. The aim was to ensure that the modelling and calculations by the design team were proven correct in the real world before offering the UAV to the public. “We’ve also adopted a higher voltage power system on this than you’d find with most commercial UAVs of this size – 25 V DC on a lithium-ion battery to be specific – whereas you don’t usually find anything higher than 15 V, unless it’s a larger or older system,” Maglio said. “That means the current-to-energy output ratio is lower than the industry average, and with a lower current you can use smaller wires and PCBs, saving a lot of weight on copper and silicon.” The Endurance’s empty airframe weighs 3.2 kg, and the battery holds about 200 Wh of energy; a smaller pack with 130 Wh is available for those who want to transport the UAV and its equipment by commercial airliner. The UAV also uses the P-DDL encrypted data link from Microhard for telemetry and control, as well as a handheld GCS built in-house for the ground receiver component of the data link. DroneInch was at the show to explain how it has developed software aimed at improving the autonomy and data gathering of UAVs in agriculture, having identified some critical shortcomings in typical unmanned aerial farm survey operations. “A successful farming operation requires an ecosystem of geographically separate specialists, including agronomists, bio-scientists and locally distributed field supervisors who know closely how, when, and where problems with different crops can be found,” Srivatsan Desikan explained. “An effective drone survey thus requires the ability for all of them to collaborate in the data collection process without needing everyone to travel to the farm. “Also, most NDVI and other UAV agricultural survey software gives no indication to farmers what altitude or angle to fly at to give the best results.” By consulting with such specialists, DroneInch has designed its software to enable farmers to input key variables such as the crop to be surveyed, the time of year, the amount of cloud cover and the approximate geographical location of the field. The UAV’s flight automation software will be updated with the correct flight path, altitude, angle and speed at which the fruit or vegetables should be photographed. For example, strawberries will typically be surveyed from 7-8 ft above, while orange trees would be surveyed from 40 ft. Data collected during flight is uploaded to DroneInch’s cloud data visualisation web portal. Here, the agronomist, bio-scientist and others can view it, perform their own analysis and send a map with prescribed actions to the local farm supervisor. “We collected the best practices from a range of farmers, using our in-house machine learning systems to identify which practices yielded the best results, in order to ensure our software could prescribe the right flight paths for each crop,” Desikan said. “It’s very difficult for any one farm to have expertise in UAV operation and how to apply it optimally to every type of crop, but by analysing large quantities of crowdsourced anonymous data in the way we have, our software can provide that expertise and make adoption of UAVs in agriculture that much smoother.” Nottingham Electrification Centre, a spin-off company from the University of Nottingham, in the UK, develops a range of electric motors and motor control systems for UAVs, which it exhibited at the show. “Our core technology is centred on sensorless field-oriented control, which when compared with typical BLDC motor control methods that rely on a non- sinusoidal square-wave, provides much higher power and energy efficiency. It also generates much less vibration and noise,” said Tianhao Wang from the centre. October/November 2019 | Unmanned Systems Technology DroneInch’s software is designed to improve agricultural surveys