The sky’s the limit
WHEN designing a multirotor drone platform, ease of operation, price point and maintenance cost must all be factored in, as should the scalability and ease of customisation.
It is rare that a single platform can do everything. Skyline UAV has developed Skyhawke, a Y6 coaxial tricopter, as a solution to some of the problems it had found with its existing fleet of single rotor machines.
The software, much of which was produced in Europe, lacked certain features and controls such as the ability to create survey patterns and automated payload controls, and the aftersales support could take weeks or even months for a machine to be returned, which was costly not just for the price of repairs, but also in lost downtime.
Skyline UAV has taken its firsthand experience with these problems and built a fully customisable solution right here in Australia – Skyhawke.
The build
Skyline UAV used its extensive knowledge of, and many years working with, UAV technology to design and build Skyhawke 100pc in-house.
The process began with several known parameters and was then fleshed out in CAD.
A smaller prototype aircraft was built from low cost materials in order to test the concepts and to identify any weaknesses or potential improvements.
After testing, the final CAD files were prepared for a full carbon frame construction.
The multi-rotor frame was chosen because if offers several advantages over single-rotor helicopters.
Firstly, they are cost-effective.
Single rotor helicopters require complex control and drive systems which makes them very expensive to produce, and to operate.
Secondly, the multi-rotor aircraft have much fewer moving parts and so they are much more accessible, easier to maintain, and less likely to suffer from control failures due to fatigue and improper setup.
Thirdly, multi-rotor aircraft have a certain level of motor redundancy built in, which improves flight safety and makes them safer for use in high-risk environments.
Last, but certainly not least, multi-rotors were selected for ease of operation and the ability to hover and to move equally well in any direction, regardless of which direction the nose is facing – which makes them particularly useful for survey and inspection tasks.
Electric motors were chosen over fossil fuel motors for two reasons.
Firstly, they have no internal moving parts – this makes them virtually maintenance-free for their service life.
Secondly, they can operate in areas where the use of fossil fuel combustion engines is not viable – whether that is because it is too noisy, too remote, or too dangerous.
Endurance is always the trade-off with electric motors.
Skyline UAV’s chief remote pilot, Mike Walters, says that most of the figures quoted by UAV companies are unrealistic, as they are based on zero payload, and using 100pc battery capacity in perfect operating conditions.
“Weight, temperature, wind, humidity, elevation, battery condition, etc, will all impact endurance,” he said.
“As such, we have tried to obtain realistic data for the Skyhawke and continue to update our information over time.
“Skyhawke, with a moderate payload under normal operating conditions can stay aloft for 20-30 minutes.
“This is comparable with the real-world performance of other aircraft in its class.
“However, by using off-the-shelf lithium polymer batteries we can use multiple configurations to achieve different performance.”
Skyhawke can also be built to full custom specifications, due to the in-house capabilities of the Skyline team.
Whether it is as simple as integrating different payloads into the build, or as complex as completely re-sizing the aircraft for different power systems and performance, Skyline has CNC and 3D printing machines on site that can quickly prototype and manufacture new components for any number of applications.
To resolve the software incompatibility problems, Skyline opted for the Pixhawk flight controller, which runs open source software.
This means that Skyline has access to the massive community of developers who are constantly updating and innovating, as well as providing timely support and a lively product development cycle.
For Skyline, the main purpose of the smaller Skyhawke MR6 was as a survey platform that was fitted with a FLIR Duo Pro R camera package.
The larger Skyhawke XL has been used as a precision lifting platform, and has also been configured to carry Skyline’s Infernus aerial incendiary unit.
Put to the test
Skyline UAV was recently engaged to assist with the replacement of a power cable between two electricity pylons in a remote, densely forested area.
The pylons were 300m apart, with 120m of vertical separation between them – you can see the image in Skyline’s advertisement on this page.
Skyline elected to use the Skyhawke XL as it was easily capable of lifting the cable leader and could be transported to site in a 4wd with minimal ground support equipment.
The lift was carried out at first light in cold and windier conditions than expected, however the aircraft was still able to complete the job with an impressive level of precision and stability.
The cable was placed with great accuracy and the client was able to achieve a successful outcome as a result, and with considerably less risk and cost than if a manned aircraft had been used.
Due to the heavy tree canopy and steep slope, the company did encounter some difficulty with visibility and data telemetry.
As a result, it has identified a need to always place the ground station at the lowest elevation, and will be working with Helicopter Lifting Services (another Skyline company) to identify how full-size procedures can be adapted to UAV with regards to ground crew and communication.