Project number: IA_2021_10_TWINS
Co-operation partners involved:

Introduction: Diverse developments and trials

The twinSCIENCE test platform (see Fig. 1) promotes innovative collaboration with AIRlabs and enables a wide range of developments and tests. The platform enables rapid iterations between design and testing of methods and algorithms. The efficient development of new autonomy, control and mission elements for drones is made possible by the partnership with the University of Klagenfurt.

Project description/methods: 

The upgrade project comprises an upgrade of the twinSCIENCEV2 flight platform to enable longer flight times under maximum load. The project was carried out in the second half of 2021 and completed in 2023. Mechanical, electrical and software modifications were originally planned, but the latter could not be implemented after a thorough review due to resource constraints.

The implemented upgrade includes mechanical and electrotechnical adjustments. The platform is provided as a test infrastructure for AIRlabs (see service catalogue) to meet various user requirements and to be used in different test scenarios for various flight manoeuvres and engine configurations.

Mechanical modifications 

The following improvements were made as part of the mechanical modifications:

• Optimisation of the landing gear to ensure increased stability for hard landings. The landing gear is light and springy.
• An EMC optimisation allows an RTK sub-cm fix in good-natured environments, even if a companion board (e.g. Raspberry-PI or Odroid), USB3 camera and other sensors are also in operation.
• A lighter design results in noticeable weight savings (e.g. >30%). Slight losses in terms of mechanical robustness can be accepted (e.g. external cable routing, sandwich structure instead of cavity structure, etc.). Racecopter frames can serve as a model.

Electrotechnical adaptations

The electrotechnical modifications include the following aspects:

• Integration of a reset switch on the PX4 for separate control of a reboot or power interruption.
• An option for a simple battery hot-swap has been integrated to enable a battery change without affecting the running software.
• The IMU supports a high readout frequency (up to 4 kHz) for gyro and acceleration. 
• A telemetry data link via X-Bee or similar LoRa-methods is available to ensure long range and robustness.
• The power supply meets the requirements of companion boards (e.g. Odroid) with a supply of approx. 8-12A without voltage dips.
• A number of GPIOs can be controlled via Companion Board and PX4, especially for hardware-based time synchronisation of external sensors.

Further customisations 

A new power/PWM board was developed to re-equip the arms with connectors for power and PWM signals and thus facilitate replacement. A switch was also made to 6-cell batteries.

Testing and validation in the drone hall

Where applicable, the above points were tested and validated in the AAU drone hall in collaboration with the University of Klagenfurt.

For a further description of the adjustments made, please see the enclosed final technical report.
(Please note that the technical project report is only available in German.)