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Onboard Active Safety System


Due to the growth of complexity and cost of aviation operations caused by the increase in the number of aircraft and air traffic, it has become clear that in the not too distant future it will be impossible to provide and maintain appropriate levels of flight safety with the current safety systems and aviation infrastructure. The aim of the ONBASS project, therefore, is to propose, analyse and develop the innovative Principle for Active System Safety (PASS) for aviation. Rather than just recording data during an aircraft’s flight, in order to allow post-crash analysis to be carried-out, ONBASS proposes the analysis of available data in real time during the flight and reacting on them with the aim of accident prevention.

Project objectives

ONBASS is concerned with the formulation of the theoretical principles of aviation system safety: the flight safety (risk) model, the information flow model and the control system model. These models make it possible to determine the scope of the applicability of ONBASS. Subsequently, analysis of the dependencies within and between the models will permit the definition of the features, functions and structures of the system, software and hardware. A comparison between the existing and the proposed system structure of aviation safety will be drawn-up with the aim of optimising the project’s outcomes. To match this demand, the scope of ONBASS is the following:

1. Further theoretical and conceptual development of the active safety principle and formation of theoretical models to analyse the limits of the principle’s applicability.

2. Research and development of basic fault tolerant hardware elements for the on-board part of the active safety system.

3. Concepts, design and development of a resilient system software core for the active safety system.

In terms of the system software, the main characteristics of ONBASS will be extremely high reliability, fault-tolerant concurrency, recoverability of processed data, support mechanisms for real-time fault detection, system reconfiguration in case of hardware fault or degradation, high performance and hard real-time scheduling. In terms of system hardware, ONBASS will provide the highest possible reliability, recoverability, fault tolerance, thermal and vibration resistance, survivability and graceful mechanical degradation.

Description of the work

The initial phase of the project covers the theory and operational model, taking into account the intended application domain of general aviation. After a systematic survey of the application domain and the processing of existing statistical data within it, the profile of flight risk for commercial and general aviation will be developed. With this data available, in combination with the analysis of existing systems, a conclusion will be made about features of operational models that will enable an operational risk analysis in flight real-time. From the operational risk analysis model, a reliability model of flight will be derived, aiming at the possibility of real-time prognosis of flight risk. The programming of the reliability model and a simulation of its operation in real-time data processing will be carried out.

Based on this, the overall system will be defined and specified. The objectives of this work are to clearly and concisely define the overall requirements of the system, both from the external point of view of its users and also in terms of its internal function, and to ensure that the safety context and safety requirements are clearly defined. The outcome of this work will be a system specification covering software, hardware and overall system aspects, which include safety, certification and qualification and human-machine interface issues.

After this step, the software and hardware modules of the demonstrator will be developed in parallel. This work will begin with a definition of the respective software and hardware structures, and will be completed with the verification of the software modules and the hardware prototype. The main objective of the hardware-related work consists of developing a highly reliable system including fault-tolerant processors, system memory, flight memory and communication interfaces.

Finally, the verified software modules will be integrated into the corresponding hardware prototype and an overall system verification will be performed, making use of suitable simulation and laboratory set-ups. Once the overall system performance has been verified, the ONBASS prototype will be installed on-board a general aviation aircraft in order to verify the system in flight. However, the flight hours will be limited. This means that validation activities onboard the aircraft are out of the scope of this project.

Expected results

The expected results of the ONBASS project can be summarised as follows:

  • Availability of an operational model and a theoretical model of flight risk.
  • Rigorous system requirements for the realisation of the principle of active safety systems.
  • Conceptual design and a prototype development of the relevant system software.
  • Conceptual design and prototype development for on-board embedded hardware.
  • Overall ONBASS prototype that will demonstrate the requested capabilities in-flight.