CHALLENGE OF MODERN HELICOPTER COCKPIT Formal specification and real-time piloted simulation for avionics systems and Human Machine Interface design

摘要

The extraordinary development of electronic and computing resources in the last decade has led to a significant increase in number and complexity of the avionics systems embedded on modem helicopters. The corresponding design & development process is thus facing the following challenge : to provide the crew with an easy access to an always increasing volume of information and functions, while maintaining the workload at the lowest possible level. Moreover, this development process has to cope with more and more severe schedule and budgetary constraints. In order to meet this challenge, Eurocopter has adopted since several years a new approach with prototyping and simulation techniques based on efficient computer aided design & specification tools. These tools use high level formal language and technical data base management. Their sound implementation allows upstream prototyping and simulation while providing full permanent technical control of the data flows within and between the different system constituents. This methodology supports a "crew centered design" approach with early pilot-in-the-loop validation, thus ensuring optimum fulfillment of the user's needs. An essential aspect of the specification through formal language is the associated Automatic Code Generation (ACG) capability. Its use allows a significant reduction of the software development cycle, not only for engineering simulation and testing, but also for embedded code generation when using qualified generators. A key point of the combined use of ACG and simulation is the "single digital specification principle". The whole method contributes to reduce the number of engineering iterations as well as their duration, while avoiding any discrepancy between simulation and embedded code. It brings therefore significant gains from technical, schedule and cost standpoints. It also leads to a reduction of Life Cycle Costs by making further software evolutions easier and contributes to an optimum synergy between engineering and training simulations. The paper will present how this development methodology is being applied on development programs such as NH90 and EC225/725, highlighting the current benefits and the expected trends for the future.