Implementation of a Combustion Analysis System for Engine Development
Initial situation and project task

FEV GmbH with headquarters in Aachen is an independent, internationally leading company for the development of combustion engines, transmissions and complete vehicle drive systems. Furthermore, FEV develops, produces, and distributes measurement and test systems for the development and final inspection of vehicle drives.

When it comes to tasks like combustion process development or calibration, engine developers need to analyse the combustion process in even more detail than ever before. Therefore, FEV has developed the FEVIS indication system in cooperation with NOFFZ which combines powerful modular hardware for data acquisition with a familiar MS Windows-based user interface.

The novel indication system contains a calculation library with more than 100 formulas which can be viewed simultaneously, calculated and stored for each individual cylinder. The system works in real-time, i. e. synchronously with the engine cycle. With the integrated engine knock analysis and the simultaneous limit value monitoring the indication system FEVIS can also be used for the safety monitoring of the engine to be tested. An exceeding of the limits can be used to control external devices via analogue and digital outputs.

Implementation and challenge

The real-time combustion analyser is PXI-based and contained in a 19” housing. The end product is available as 1HE or 2HE variants. With a 1 HE system size the system offers 8 fast analogue inputs, while the system size of 2 HE provides 8 to 32 fast analogue inputs and is also capable of multi I/O operations.

Each input has a channel gain which can be individually programmed via the software. Since data acquisition must be precise and performed in real-time, high data rates are required for high engine speeds. This requirement is met by an analogue-digital converter per channel with a sampling rate of up to 2.5 MHz at an accuracy of 14 bit. For the reduction of the acquired raw data the system can store 3 different resolutions per cycle.

Apart from the powerful hardware for real-time calculation, FEVIS offers specific algorithms for combustion process, injection and knock analysis.

The parallel acquisition of standard combustion data allows a cycle-resolved correlation. Limit values can be shown on the screen, analogue and digital outputs can be used to control external devices. Among those are 8 slow A/D input channels, 4 A/D output channels, 16 TTL input channels as well as 8 TTL output channels.

The user PC for system control and operation is based on a Windows operating system.

To evaluate the generated measurement results most efficiently on different systems, the data can be stored in the corresponding various formats.

Conclusion

The FEVIS system offers engine developers and producers real-time analysis for the optimisation and calibration of the products with simultaneous safety monitoring of the engine to be tested.  The company NOFFZ is the development partner and therefore responsible for the selection of hardware components, development and production of system-specific hardware and manufacturing of the first prototypes. FEV is delighted to welcome NOFFZ as a competent partner for the further manufacturing, assembly and testing of the FEVIS system.