Integrated emergency power supply for autonomous drone system

Sunflower Labs has developed the Beehive system, an intelligent and fully autonomous drone security solution that can quickly reach any location within an area and deliver live video footage from there. In order to ensure that the Beehive system is ready for operation at all times and is able to perform control flights or terminate in a controlled manner even in the event of a power failure, it was necessary to develop a reliable and integrable emergency power supply for outdoor use.

In this case study, you can read how Bicker Elektronik was able to meet this challenge with a suitable DC UPS solution, so that the system is always ready for the next flight when it really matters.

The flexible Beehive drone security solution from Sunflower Labs essentially consists of two main components: The ‘Bee’ drone has sophisticated technologies for autonomous take-off, flight, and landing, as well as high-quality live video recordings. The ‘Bee’ detects unexpected obstacles and changes the route to avoid collisions and improve future flight paths. The base station ‘Hive’ not only houses and charges the drone fully automatically but is also the ‘brain’ of the entire system, processing, and analysing sensor data with embedded AI computing.

Autonomous drone security system for property surveillance

The Beehive system enables autonomous monitoring of large areas and can be seamlessly integrated into already existing infrastructures with security cameras and sensors. After the top cover of the outdoor base station ‘Hive’ opens in the event of an incident, the ‘Bee’ drone takes off in less than five seconds and flies autonomously directly to the location of the event to transmit live video footage from there. With advanced 3D mapping, obstacle detection and geofencing, the drone navigates autonomously within the property. For example, it is possible to proactively respond to activity on any part of a 10-hectare site in less than 30 seconds. This means enormous cost and time savings compared to traditional security solutions with manned patrols and numerous permanently installed surveillance cameras. To ensure a reliable and uninterrupted power supply to the ‘Hive’ base station, Bicker Elektronik had been brought in as a UPS and power supply specialist to develop a customised solution.

The challenge

Safe operation even in the event of a power failure

During the product development of the ‘Hive’, it quickly became clear to those responsible at Sunflower Labs that the Beehive drone system should be able to safely carry out a surveillance flight or reliably return to the base station even in the event of a power failure. The biggest challenge was to find a UPS solution that would provide the required power and at the same time fit into the limited space available in the ‘Hive’ housing. In addition, all components of the emergency power supply had to be designed for long-term operation in extreme outdoor temperatures.

The solution

DC UPS emergency power supply with LiFePO4 high-performance battery

During the consultation for the design-in process, a comprehensive analysis was conducted on the power requirements and other criteria to ensure a one-hour backup operation for the base station. Based on these findings, the team of experts from Bicker Elektronik subsequently presented a customised solution: a space-saving and flexibly integrable 24V DC UPS solution with a powerful LiFePO4 high-performance battery pack. The safe and durable energy storage is ideally suited for use under demanding conditions in the temperature range from -20 to +55°C.

DC UPS charging and control module UPSI-2406

The 24VDC supply voltage of the upstream connected AC/DC power supply unit is passed on directly to the system components of the base station by the intelligent DC UPS UPSI-2406 during normal operation. In parallel, the LiFePO4 energy storage is charged, and all relevant parameters, currents and voltages are monitored. For this purpose, UPSI-2406 is connected to the BP-LFP1325 battery pack via two lines. In addition to the pure energy transmission line (BAT PWR), all relevant operating data of the energy storage device are continuously monitored and controlled on the data line (BAT DATA) via I2C interface. In the event of a power failure or voltage dips, so-called brownouts, a MOSFET in the DC UPS disconnects the input within a few microseconds and the connected load is supplied without interruption from the energy storage device. The UPSI-2406 provides a continuously stable DC output voltage in backup mode to ensure that the control unit in the ‘Hive’ continues to function reliably and without failures.

BP-LFP1325 battery pack with lithium iron phosphate technology

In general, battery packs with LiFePO4 high-performance cells offer an ideal solution for longer bridging times in UPS systems. Thanks to their high energy density, they make it possible to ensure a consistent power supply over extended durations, all while maintaining remarkably compact dimensions. For the Beehive system, the BP-LFP1325 is used, which supplies the application for at least one hour in emergency mode. In safety-relevant applications, the BP-LFP energy storage units from Bicker Elektronik impress with their outstanding cycle stability of over 6,000 charge and discharge cycles. An integrated battery management system (BMS) monitors and controls the charging and discharging process of each individual battery cell to optimise the service life and operational safety of the energy storage unit. The integrated cell balancing system ensures an even charge of all cells, resulting in the long-term usability of the battery pack's full capacity.