Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - REPRISE (Reliable Electromechanical actuator for PRImary SurfacE with health monitoring)

Teaser

In the past years, several industrial programmes have initiated the concept of a More Electric Aircraft in order to reach objectives of reduced environmental emissions and noise. In fact, there is a general consensus in the aerospace community that more electrically powered...

Summary

In the past years, several industrial programmes have initiated the concept of a More Electric Aircraft in order to reach objectives of reduced environmental emissions and noise. In fact, there is a general consensus in the aerospace community that more electrically powered systems will lead to weight saving, reliability improvement and life-cycle cost reduction. Therefore, the use of electromechanical actuation (EMA) can be a solution to help the development of a cleaner aviation because, with respect to traditional hydraulic actuation, it is:
• Less complex because of the absence of a hydraulic system
• Better suited to long term storage since there is no leak potential
• More energy efficient compared with hydraulic systems
• Easier to install and maintain (no filtration, no bleeding)
• Less complex to control from a power-distribution and power-management perspective (power is transmitted without mass transfer)
Nevertheless, some critical issues of this technology need to be addressed. Based on this scenario, the REPRISE project is specifically focused on overcoming these issues and improving technology performance, reliability and safety using new technologies and health-management algorithms. Main technical objectives are as follows:
• An innovative electromechanical actuator (EMA) for flight-control surfaces with reduced spatial envelope and weight and with improved reliability
• Reliable health-management software for the electromechanical actuator to increase safety margins

Work performed

The project is divided into 6 work packages (WP). WP1 is related with project management and dissemination of results. About dissemination activities, one technical paper was prepared and presented IEEE International Conference on Advanced Intelligent Mechatronics (IEEE AIM 2017), Munich, Germany, on July 3-7. Two technical papers were submitted to conferences and, currently, are under review.

Other work packages are related to RTD activities and can be grouped into two main parts:
a. The first stage (WP2-WP3) was completed in the first reporting period and was focused on the preparation of the test bench, on the design of the experimental procedure and the test reporting.
b. The second part (WP4-WP5-WP6) started in the first reporting period but will be completed in the second and final one. This phase is devoted to the design of the health monitoring system (WP4), to the improvement of the current EMA design (WP5) and to experimental validation of the research activities (WP6).
In term of technical progress, the following main achievements must be highlighted for each WP.
Related to WP2:
- Development and manufacturing of the test rig for the first phase of test on the current EMA
- Failure Mode and Effect Analysis executed on the EMA similar to the one used for the first phase of test
- Definition of test procedure suitable to verify if and how mechanical degradation on transmission components (like ball screws and bearings) of the EMA under test can be monitored in real time
Related to WP3:
- First phase of test completed
- Identification of the mechanical failures features in order to perform clear and robust fault identification
- Understand how the EMA malfunction affords the operations within the acceptable conditions
- Collection of useful data for the development of change-detection algorithms.
Related to WP4:
- Definition of requirements of health monitoring system
- Simulation analysis and health monitoring software development
- Evaluation of sensors for health monitoring system
Related to WP5:
- Evaluation of new technologies and architecture in the design of an upgraded EMA with the aim to increase reliability and safety and reduce mass and envelope.
- Update of requirements to include a new fault-tolerant architecture for the EMA

Final results

The aim of REPRISE research activities is to advance the state-of-the-art in electrical actuation and in actuators’ health monitoring. These are instrumental in enabling a thorough validation of the equipment and units. Significant technological breakthroughs in the scope of the project are expected to be:
• Develop flight-representative (TRL5), electromechanical actuators able to fit within the limited envelope foreseen for their application in thin wings
• Overcome the critical issue of possible seizure of electromechanical actuators, while enhancing their reliability by means of a combination of actuator architectures with a minimum number of components, employing health monitoring system .
• Introduction and evaluation of new types of sensors that are more reliable and smaller in size and weight than current health-monitoring sensors.
• Develop the optimal architecture for a diagnostic and health-management system for electromechanical actuator that will maximise its cost effectiveness.
These technological results will contribute to foster the competitiveness of European aviation through cost efficiency and innovation. In particular, they will:
Contribute to the development of a new generation of SMALL aircraft with better handling qualities, reduced fuel consumption and lower operating and life-cycle costs
Provide a contribution in establishing market leadership for the European aviation stakeholders in electric actuation for critical aircraft systems and in the associated flight-control systems, as well as in health-management systems
Introduce a new fault tolerant architecture in order to increase safety, to reduce costs associated with non-operational aircraft status