1. Overview of Aeronautics

The challenge is two-fold:

  1. comply with the high standards, low interference levels and harsh environmental conditions of the aeronautical industry, and
  2. enable flexible and competitive applications that foster business and revenue for all stakeholders of the aeronautics industry.
The first use case (Launchers Sensor Network) will deploy a DEWI bubble to replace sensor wired links on-board a flying rocket, reducing weight and therefore improving fuel consumption, speed, or flying range. The second use-case (Increased Fuel Efficiency by Aircraft Skin Drag Reduction) will deploy a DEWI bubble to enable a dense wireless sensor and actuator network over the fuselage of aircrafts. The sensor network will track the formation of turbulent flows and relay the information to the internal avionics network and ground control. Based on the sensed information and different flight profiles, an actuation policy will be selected to counteract the turbulent flow, reduce skin drag and improve lift force.

websitefiguresFig. 1: Use case and interoperability structure

2. Specific challenges / Business needs

Two main objectives are pursued in the aeronautics domain:

1) replacing of wires to reduce weight and improve fuel efficiency, range, or speed of aircrafts, and

2) enabling advanced applications with high density of sensors and actuators to reduce turbulent flow across fuselage and also improve fuel efficiency of aircrafts.

In order to achieve these goals, there are several challenges that must be addressed. For example, the study of reliable propagation in metallic environments, resilience to high level of vibrations, accelerations, large temperature and pressure changes, design of resistant wireless links, ruggedized hardware, special antennas, supply of sensors.

By removing wires and using WSNs (Wireless Sensor Networks) weight reduction of aeroplanes, helicopters, satellite launchers will be achieved. This will lead to considerable savings in fuel consumption, improved speed as well as range. Wireless technology also provides improved troubleshooting, re-configuration, as well as more flexible deployment and aircraft design. In addition, wireless sensor nodes can reach places difficult to reach by cables.

3. Approaches & Solutions

The sounding rocket use-case (see Use Cases below) will deploy launcher sensors connected with Multi-link Telemetry Unit and with the ground operator by access points compatible with most common standards such as: ZigBee, IEEE1451, and IEEE802.11n.

In the active flow control system, patches of sensors and nodes are wired together to form a DEWI node. Preprocessing, filtering and compression of sensor information will be performed in each patch to reduce data rate requirements and improve scalability. Patches will communicate the turbulent flow layer formation across the fuselage to the internal avionics network and also to ground control. Actuation policies will be selected according to a flight profile and the collected sensor information. Synthetic jet actuators will be activated to counteract the turbulent flow formation.

websitefigures_2Fig. 2: Active flow control use case overview

websitefigures_3Fig. 3: Launcher sensor use case overview

4. Use Cases

The aeronautics domain consists of two Use Cases.

Launchers Sensor Network: Wired sensors on-board a flying sounding rocket will be replaced to reduce weight. Important data regarding operation in harsh environments (extreme temperatures, pressure, radiation, and speed conditions) will be collected.

Increased Fuel Efficiency by Aircraft Skin Drag Reduction: A novel approach together with a dense network of sensors and actuators based on the DEWI bubble shall reduce the effect of skin drag over the fuselage of aircrafts.

5. Demonstrators

Launchers Sensor Network will be demonstrated on a flying sounding rocket capable of reaching up to 8 km of altitude (see Fig. 3). The rocket has already been tested at the end of April 2015. Two further tests are envisioned with more components and more complexity on-board. The DEWI bubble will collect measurements of the rocket (temperature, pressure, etc.) and will also control some subsystems related to the parachute control and the trajectory guidance subsystems. Two additional subsystems accompany the DEWI bubble on board the rocket: the RFTM (Radio Frequency trajectory monitoring subsystem) that provides the positioning information to the guidance subsystem, and the multi-link telemetry logger (MTL) which consolidates the positioning data provided by the RFTM, and provides the interconnection between the on-board DEWI bubble, the RFTM subsystem and ground control.

Increased Fuel Efficiency by Aircraft Skin Drag Reduction will be demonstrated by re-creating a small section of an aircraft wing. A set of sensors and actuators will be deployed over the wing area. The test will be per-formed in a wind tunnel with and without the active flow control system. The test will measure the difference in lift force for different values of the angle of attack and wind speed. For practical purposes, sensors will be grouped in patches. Sensors inside a patch will be wired together. Once the central unit will collect measurements of a patch and relay compressed information via wireless to the sink of the DEWI bubble. This hybrid wired/wireless architecture is particularly attractive to deal with highly dense wireless sensor and actuator networks. It is expected that compression tools will allow the system to reduce the amount of data to be transmitted through the network. In turn, this will improve scalability and will make system design more flexible, particularly in the design of the wire-less links.

6. Deliverables

There have been six deliverables produced so far.

  • DEWI Deliverable D200.001 „Project Plan“ produced the details of the project plan for the aeronautics domain.
  • DEWI Deliverable D204.001 „Subsystems Requirements“ related to concepts, requirements and specifications of use case 2.4 (Multilink Telemetry Logger – MTL in Space Test). The deliverable included a detailed specification of the rocket subsystems to be constructed and an analysis of wireless sensor network technologies to be potentially used. The review of WSNs included both common standards such IEEE802.15.4. Extensive simulation and analytic work has been achieved from WSNs in the rocket scenario.
  • DEWI Deliverable D205.001 „Concepts, Requirements and High-Level Architecture vor Wireless enabled AFC“ produced the concepts and requirements for use case 2.5 active flow control based on dense wireless sensor and actuator networks. The document included a detailed review of the state of the art of sensors for avionics applications, the basics of turbulent flow and the need for skin drag reduction, a review of actuators based on synthetic jet fluidic injection, existing wireline networks based on CAN and the AFDX system, and a review of wireless applications in avionics.
  • DEWI Deliverable D204.002 „Subsystems detailed specifications“, provided further detail on the specification and subsystems of the rocket case.
  • DEWI Deliverable D205.002 „Simulation Framework (including FSI and WSN simulation) addresses the definition of the simulation framework of the AFC system, including computational fluid dynamics (CFD), electromagnetic propagation modelling, wireless sensor network simulation and the interaction with the internal avionics network of a short-haul commercial aircraft.
  • DEWI Deliverable D206.001 „Ph1 Aeronautics Domain Technology Items (Phase 1)“ is the deliverable of the interoperability mirror work-package. The objective of D206.001 is to provide an overview of the technology items related to the aeronautics domain as well as their specific requirements. The technology items lie at the core of the interoperability and cross-domain reusability of DEWI project.