KnockIT (Knock Indication Tool)
As the name suggests, the main purpose of this tool is to speed-up the engine calibration process by doing a real time evaluation of a knock related index.
How it works?
The algorithm core is the sampling and filtering process. The konck indexes can be evaluated starting from signals coming from a transducer. These can be accelerometers, in-cylinder pressure sensors, ionization current, or other sensor that produce knock related signals. The signal is sampled at high frequency, typically 100kHz, windowed and filtered. The filtering process is done in the digital domain and it's characteristics are completely configurable by the user. At the end of the digital conditioning process, the signal is ready to be processed and one or more indexes can be synthesized. Even the index algorithm is developed based on the customer requirements, with great flexibility. The knock index, which is computed cycle-by-cycle, cylinder-by-cylinder, is then visualized on the operator monitor, along with many statistical indicators, also customizable. The tool can communicate with the real world in may ways, including analog and digital I/O and protocolled busses, like CANbus and RS232.
Features
- High frequency sampling of the transducers signals
- Parametric windowing of the sampled signal
- Digital IIR filtering (up to 8 poles, bidirectional zero delay fillter)
- Flexible engine position sensing (handles multiple configurations)
- Custom knock index evaluation (eg. MAPO, Integral, Third derivative)
- Real time input signal monitoring (scope like visualization of the windowed signal)
- Synchronized acquisition of knock indexes evaluated by external third party system .
- Streaming data acquisition of the sensor data, including the angular position references.
- Real time statistical indicators evaluation
- Real time visual and electrical alarms , based on user selectable parametric knock thresholds
- Time history chart of the past knock indexes
- Cycle based data acquisition
Performance
The tool is very scalable with respect to cylinder number, engine speed, types of sensors.
Following are the performance figures different configuration examples.
#1 - V12 engine equipped with in-cylinder pressure transducers
- Maximum engine speed: over 16000 RPM
- A 180° combustion window is handled, combustions can overlap.
#2 - 6 cylinder engine equipped with in-cylinder pressure transducers and 2 accelerometers
- Maximum engine speed: over 16000 RPM
- Simultaneous real time evaluation of multiple knock indexes, based on in-cylinder pressure AND accelerometers
#3 - 4 cylinder engine equipped with in-cylinder pressure transducers or accelerometers
- Maximum engine speed: over 22000 RPM
- The knock index evaluation can be carried out on overlapping combustion windows (like "big bang" engines)
Hardware requirements
The tool relies on a National Instruments real time controller (CompactRIO or PXI), an FPGA board and the I/O modules necessary for the application, whose type and number can vary depending upon the specific application requirements.
Software requirements
The software is provided as a royalty free compiled executable,which means that no other licenses are required (i.e. National Instruments Labview), apart Alma Automotive's.
For pricing, demo versions and further information, please contact us.
