Diesel ecu mapping optimization for aircraft and helicopter applications

Starting from a good automotive engine is always a good idea, also for brand new automotive design. In the case of automotive to aircraft conversions, the automotive engine is modified as little as possible. This approach has several advantages: reduced development time, good reliability and availability of cheap and worldwide spare parts. What it may appear a good idea is to tune up the original ECU (electronic control unit) by using one of the several softwares available on the market. However, this approach is not feasible even for ultra light aircrafts. This is due to the lack of control on the software of these ECUs. In fact, automotive software timing or ECU set-up is performed in the following way. The final ECU manufacturer (who holds the responsibility of the hardware and the software in the final car ECU) supplies to the car manufacturer a “development ECU” with a “development Software”. This system is tuned on the engine and on the car to fulfill the car manufacturer requirement. When the tuning is considered satisfactory, the “maps” (the data inputted by the manufactured) are given to the ECU manufacturer. This later translates the data into the software of a “production ECU”, that is given back to the car manufacturer for final validation prior to serial production of ECU and car. In this case, even the car manufacturer does not have a full control of what happens inside his ECU. This is logical since the full responsibility is given to the ECU part supplier. So the tuning of a serial production ECU is more than a true programming. Results are unpredictable to a certain extent that depends on the level of knowledge of the person who performed the tuning and of the software house that implemented the software. The software that truly runs on serial production ECU is a well kept secret of the ECU manufacturer, since it is the knowledge of ECU. The simpler is the software the less expensive will be the ECU and the larger the profits of the ECU supplier. Tricks are hidden inside the ECU to obtain these results; these tricks multiplied per millions of ECU give the supplier a competitive advantage. So, even the car manufacturer has a limited control on what happens inside the real-time software of the ECU, what emerges is the engine and the car behavior. Aircraft conversions require the replacement of ECU, wirings and sensors with appropriate units. This assembly with its own software constitutes the aircraft FADEC.