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Flight Critical Wireless Slip Ring for Civil Tiltrotor

Periodic Reporting for period 2 - Constance (Flight Critical Wireless Slip Ring for Civil Tiltrotor)

Reporting period: 2018-10-01 to 2020-01-31

This project aims to the integration of a flight critical contactless power and data transfer unit into the NGCTR Technology Demonstrator (TD) prop-rotor system. This technology demonstrator is based upon the existing AW609 platform.

Slip rings are necessary for monitoring of flight-critical electrical equipment in the prop-rotor system. Additionally, during experimental flight activities, slip rings are required to transmit instrumentation data across the rotating to non-rotating systems boundary. The slip ring is required to deliver sufficient power to the rotating system to operate the rotating portion of the slip ring and the electronic control and data management systems in the rotor.
A contactless transfer is highly desired for their high bandwidth and reliability capabilities to support flight-critical signals and/or large volumes of experimental data.

The aim of Constance is therefore to enable an innovative flight critical contactless rotating power and data transfer unit (CRPDT) to be developed for demonstration on the flying technology demonstrator, at TRL6 which provides electrical power and a bi-directional data link to components mounted on the prop-rotor.

In order to meet the overall safety objectives the TD assumes a dual power and data channel on each rotor including a redundant azimuth sensor. The development of the flapping sensor and related flapping sensor controller are covered in the Clean Sky 2 FlapSense program. Optionally an Ethernet data channel for the Flight Test Instrumentation can be connected.
After the first PDR new layouts of Constance have been evaluated, in close collaboration with the TM, to meet the new requirements and interface constrains. As a result of the first PDR the design of Constance has been completely revised to meet the new requirements. The new conceptual design provides an integrated dual CRPDT which meets the safety objectives and is much smaller and lighter compared to the first concept. The third data link is embedded in the second CRPDT channel of Constance.

Parallel to the conceptual design of Constance technical parts have been detailed designed and tested with produced breadboards to evaluate the feasibility.
Slip rings for transferring power and data commonly form the interface between a rotating environment and a stationary domain. For aerospace applications, currently only conventional slip rings, with brushes, are on the market. A few commercial wireless slip rings are available, however not designed and certified for aerospace applications. For such a flight-critical application in such harsh environment, a fault-tolerant design has to be taken into account from the start of the development.
One of the main impacts of this concept is to aim to deliver superior vehicle productivity and performance. Constance will still be the first aerospace certified wireless slip ring. This enables a safe and highly reliable link in the flight control system, which is a crucial technology component in the NGCTR.