RECONFIGURE stands for "Reconfiguration of Control in Flight for Integral Global Upset Recovery" and is an FP7-AAT-2012-RTD-1 aeronautics European project that started in January 2013 and is expected to conclude by June 2016.
Initially coordinated by Dr. Marcos during his time at Deimos Space (Spain), the TASC group is now a technical participant focused on fault tolerant control techniques based on H-infinity for C* control laws.
The webpage of the project is: http://reconfigure.deimos-space.com/
Currently, Airbus’ aircraft fault tolerant control (FTC) strategies in the flight control system (FCS) are based on fail-safe approaches whereby a nominal (normal) control law is switched first to a robust (alternate) solution and then if necessary to a direct law, which ensures a minimal level of stability augmentation. Each control law is designed off-line for different levels of robustness and each includes a set of specific guidance and control (G&C) functions which assist the pilot during flight. As the control law is switched from ‘normal’ to ‘direct’, see Figure 1 on the left, some of these functions are switched off (e.g. autopilot, flight management), increasing the demands on the piloting task. Nevertheless, this state of practice is fully compliant with airworthiness regulations and fits well in the certification process.
More advanced and less conservative FTC-FCS approaches have not been used yet mainly due to:
The current FTC-FCS approach was established since aircraft makers seek, above all, a safe and acceptable performance (robust stability). But nowadays it has been identified that there is a need to change the design paradigm for future aircraft towards a robust performance approach:
Full-time and all-event availability of performance optimised G&C functions
This paradigm can be translated into the desire to extend the operability of the G&C functions that assist the pilot in keeping the flight safe, making the mission optimal and easing the flight task. This is visualised by the shift, seen in Figure on the left, from the dashed (current) to the solid line (the desire innovation).
The main goal of RECONFIGURE is to investigate and develop aircraft guidance and control technologies that facilitate the automated handling of off-nominal/abnormal events and optimise the aircraft status and flight. The automatism will help alleviate the pilots’ task and optimise performance by automatically reconfiguring the aircraft to its optimal flight condition. This goal will be achieved by pursuing four main scientific and technological objectives within RECONFIGURE:
1. Advanced parameter estimation and fault diagnosis approaches;
2. Reconfigurable G&C approaches;
3. Integration issues and approaches for estimation, diagnosis and G&C;
4. Clearance approaches for the above type of systems (individually and integrated).
Description of Work
The project is divided into five main work packages (WP).
WP1: Industrial benchmark and assessment tools: the benchmark (i.e. the aircraft model and scenarios) is defined and developed. It also includes the definition of the designs’ evaluation matrix and the verification and validation (V&V) process and tools to be used in WP3.
WP2: Advanced G&C design and clearance methods and tools: this is where the main research and development activities are performed. There are three main phases: a research and development (R&D) phase, an application phase, and an evolution phase where the methods from the R&D phase can be evolved, based on the lessons learnt in the application phase.
WP3: Industrial V&V: this aims to evaluate the technological readiness level (TRL) of the developed approaches by performing a traditional industrial V&V in two-steps: verification of the designs in a functional engineering simulator with traditional Monte Carlo analysis, complemented by worst-case search tools and a validation of the designs in the Airbus V&V process. This will include tests with pilot-in-the-loop simulations using a real flight code and avionics.
WP4: Dissemination and exploitation activities: this is established for the dissemination (publication) and exploitation (patenting) activities, including the final definition of a road-map for future research.
RECONFIGURE’s goal has a long-term perspective of helping to develop the fly-by-wire (FBW) of tomorrow. The development of such a FBW will provoke a major change in the design paradigm currently followed by the aeronautical industry, where a conservative design is favoured over a performance-orientated one. However, it is highlighted that RECONFIGURE does not aim to be able to provoke such a change, but rather that it aims to achieve the small steps necessary to initiate such a change of design mentality.
With regards to a mid-term perspective, RECONFIGURE will provide solutions that can extend the operability, or improve the design, of the G&C functions implemented in the current FBW in order to assist the pilot in keeping the flight safe, making the flight task easier and optimising the mission.