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Products / Combustion Analysis


Compact and Rugged Combustion Analysis System for use on Vehicles, Motorbikes and Test Benches

OBI-M2 is our most compact on-board combustion analysis system implemented on MIRACLE2. It is an extremely compact and fully featured combustion analysis system suitable for use on test benches and on-board, tested and validated in the most demanding racing world. It can be connected to standard crankshaft position sensors, without any crank angle adapter needed. Optional integrated charge amplifier Alfa Centauri for piezoelectric pressure sensors.

When connected to the application engineer’s laptop, OBI-M2 user interface allows real-time streaming of cylinder pressure signals over ethernet and high speed data acquisition for post-processing view and analysis.
Among its several usage patterns, OBI-M2 can be used to develop and optimize the engine calibration both on the test bench and on-board, thanks to the additional information regarding combustion. It is also a monitoring system, as OBI-M2 detects any limit value violations defined by user and saves the raw data along with a pre-event and post-event history. Alternatively, OBI-M2 is very well suited for combustion analysis and control in vehicles or motorbikes as a standalone system, thanks to its 32 GB on-board data storage.


The combustion analysis toolchain


CAS toolchain

Distinctive features at a glance

  • Up to 12 cylinders engine (24 analog inputs overall)
  • Direct connection to standard crankshaft position sensors, without any crank angle adapter needed
  • Extremely easy and quick installation on-board
  • Time-based combustion analysis system
  • Time-to-Angle conversion performed with the interpolation approach for the highest precision
  • Real-time, cycle-by-cycle and cylinder-by-cylinder evaluation of combustion parameters 
  • Combustion parameters published via CAN and XCP on Ethernet
  • Easy integration with ETAS INCA®, VECTOR CANape® and ATI VISION®, or any environment supporting CAN and XCP
  • User interface for in-cylinder pressure and combustion data monitoring
  • Data acquisition based on analog trigger or eventbased (limit value violations)
  • Stand-alone ECU-like operation 32 GB on-board storage
  • Crank angle-based actuation tracking




System components


Overview of the complete on-board combustion analysis system:

  1. Cylinder pressure sensors
  2. Miniature charge amplifier Alfa Centauri
  3. Engine position sensor connector
  4. Power supply 6-26 VDC
  5. Host PC for run time visualization and data acquisition (standalone operation without PC is also possible)




Real-Time combustion analysis

The combustion analysis system evaluates in Real-Time and publishes on the CAN network:

  • Pmax, APmax
  • Cumulative Heat Release
  • MFBxx angles (xx defined by user, for example: MFB10, MFB50, MFB90)
  • Knock indexes (MAPO and integral)
  • Crank angle-based actuation tracking

Configuration of the algorithms includes (but is not limited to):

  • Engine geometry
  • Low-pass and high-pass digital filtering of pressure data (IIR, 2nd order)
  • Angular windowing for knock analysis
  • Crankshaft position sensor and analog input filter delays (delay compensations)




Software Specifications

  • Oscilloscope-like chart, for cylinder pressure signals monitoring, with overlap and time-based functionality
  • Main page with moving average values of combustion parameters
  • Tabs with statistical analysis (CoV, max, min, average, percentile) of combustion parameters
  • Chart with selectable combustion parameters trend over the last x engine cycles (x up to 1000)
  • Automatic TDC determination procedure, based on peak pressure angular position monitoring during misfire or motoring, with loss-angle input from the user. Alternatively with capacitive TDC sensor
  • X-Y graphs with IMEP vs MFB50 and MAPO vs MFB50 (X and Y axis can alternatively be defined by user)
  • All parameters are tunable from the user interface and then downloaded on the real-time unit for standalone operation
  • Unlimited acquisition on host PC of high frequency data for off-line analysis 
  • Synchronous acquisition of cycle-based data and high frequency data on separate files for easy viewing and reporting


Hardware Specifications

  • CNC machined aluminum case, completely sealed with the availability of customization on user specs
  • Designed and tested to withstand use in environment with high vibration levels
  • All signals are cabled with user defined termination (Race connectors are used by default)
  • Powered by National Instruments SOM (Xilinx Zynq™, with Dual Core ARM® processor, Artix-7 FPGA on top and 512 MB RAM)
  • 2 Variable Reluctance Sensor interfaces for direct reading of CRANK and CAM signals 
  • CAN bus output of all the combustion parameters and status information
  • High accuracy over the full operating envelope (temperature and voltage)
  • Possible integration of high fidelity microphones (audio)
  • Ethernet port for monitoring and configuration




Customization/Software requirements

User defined functions can be implemented on request.

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.


Price list

Up to 6 cylinders engines (12 analog inputs overall) 13121 € ex. vat

Up to 12 cylinders engine (24 analog inputs overall) 19068 € ex. vat

The upgrade from 6 cylinder version to 12 cylinder version can be performed anytime on the hardware 

already purchased. The additional cost is only due to the license upgrade.


The wiring harness is not included in the price. Alma Automotive can provide Breakout boxes or custom wiring harness based on customer specifications.



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 For demo versions and further information, don't hesitate to contact us.


National Instruments


Unibo Motorsport


NIDays 2013

Gli aiuti di Stato e gli aiuti de minimis ricevuti dalla nostra impresa sono contenuti nel Registro nazionale degli aiuti di Stato di cui all’art. 52 della L. 234/2012 e consultabili qui

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