Volz Servos has provided Netherlands-based High Eye with a standard Volz actuator with special custom-made adaptions for its Airboxer unmanned helicopter to enable reliable and safe steering.
At the heart of the Airboxer helicopter is a complex flight control system, which requires actuators to stabilize and provide motion to the rotor systems. Additionally, the Airboxer is designed to safely operate in challenging environments, such as arctic areas, deserts, over the sea or in urban areas. Therefore, the helicopter needs actuators that withstand high vibration levels, heat, moisture, impacts and rapidly oscillating control inputs.
“The current solution we created with the Volz Servos is the most reliable concept that High Eye has ever created and is unrivalled in the market,” said van de Ruit. “It uses the most reliable and robust actuators on the market.”
The solution the Volz Servos experts created with High Eye is based solely on the standard Volz DA 15-N actuator line. Five DA 15 N-ISS servos ensure reliable and safe control of the swashplate below the rotor on the Airboxer. In this way, the servos realize the attack angle of the rotor blades and the direction of flight of the helicopter.
The DA 15-N actuators are part of Volz’s standard range and were originally developed to withstand impacts to the control surfaces during net landings without functional impairment or damage.
“The brushless motor and the ISS gear protection system with slip clutch make the servo by far the most robust of this size on the market,” explained Volker Hammen, Head of Development at Volz. “When shocks or strong vibrations occur, the drive slips from a certain torque and thus prevents the gearbox from being damaged.”
“If anything can be said about helicopters, it is that they can definitely be the summum of complexity from the perspective of the designer,” said High Eye CTO Marijn van de Ruit, who was a commercial airline pilot before joining High Eye. “Every part of the construction requires careful evaluation to at least create an expected level of reliability.”
van de Ruit says that one safe way to ensure this reliability is through redundancy. With Volz Servos, High Eye continued to follow the path of redundancy – with the consequence of creating extra complexity.
“But the numbers don’t lie: the amount of non-recoverable incidents has never been lower,” said van de Ruit.
To ensure redundancy, Volz and High Eye decided to install five DA 15-N-ISS to the swashplate – as three fixed contact points are defining a flat surface, two of the actuators could theoretically fail and the helicopter still remains safely controllable.
“Ultimately, we were able to solve the challenges with High Eye’s Airboxer, the high mechanical loads on the actuators, with one of our Servos from the standard range,”said Volz CEO Phillipp Volz. “We then adapted and designed, for example, the different cable lengths exactly according to customer requirements.”
“A single actuator failure is almost unheard of considering the types that have been chosen – but even in the case of a mechanical or electrical failure, the flight control system continues to behave normally and allows the safe recovery of the helicopter,” van de Ruit concluded.
High Eye designed the Airboxer VTOL UAV to get in and out of hard to reach locations to collect valuable data or transport goods up to a payload of 7kg. The NATO STANAG 4738 compliant platform can be adapted to a variety of mission requirements or applications and can be integrated in challenging environments with ease. The heavy-fuel (Jet A-1) driven UAV enables seamless integration into a ship’s combat system as well as a command vehicle.