Optical engines have been a part of cutting edge combustion research for over 20 years.  Quartz and sapphire ports through piston crowns and cylinder walls enable researchers to analyze combustion events with high powered lasers and precision cameras.  Controlling the laser and camera equipment requires precise digital commands generated in both angle and time domains.

Drivven now offers a precise optical engine triggering system based on CompactRIO from National Instruments.  The system integrates Drivven's Engine Position Tracking (EPT) VIs and Engine Synchronous TTL (ESTTL) Output Module Kit, with a customizeable LabVIEW real-time application for sweeping trigger angles and durations as well as programmable numbers of on/off cycles for outputs.

The base system hardware provides six differential digital inputs for crankshaft encoder and cam phase signals, and eight TTL outputs for triggering various test cell devices such as lasers, cameras or injector drivers.  The CompactRIO platform offers much more room for optional expansion to include multi-pulse, direct injector driver modules and lowside rail pressure solenoid driver modules for complete fuel system control.

The base system software allows independent control of each TTL output.  Each output can be configured to operate in start-angle or end-angle mode along with a specified duration.  Output pulse polarity is individually set.  A 3-pulse injector command can be generated internally or triggered externally from a single digital rising edge.  A spreadsheet file can be transferred to the controller and used as angle-sweep or on-off profiles. 

Drivven can also provide turn-key PXI-based systems which can perform combustion analysis (DCAT) and data recording within the same engine control application.  These applications can be provided as open-source for further modification by the customer using LabVIEW development tools.

Our base CompactRIO optical engine control system includes the following:

8 Channel ESTTL Output Optical Engine Control System

1 cRIO-9012 RT Controller

1 cRIO-9101 4-Slot FPGA Chassis

1 Drivven ESTTL Output Module

1 cRIO-9411 Digital Input Module

Each system is delivered with an installed executable application which runs at power-on.  The system provides a CalVIEW user interface which allows the user to configure the various engine-synchronous outputs on-the-fly and save the settings.  The calibration settings are stored on the cRIO controller and used immediately upon system boot.  The user interface is accessed by connecting a computer directly to the CompactRIO controller via an Ethernet crossover cable or by putting the system on a network.  LabVIEW development tools are NOT required, but the free LabVIEW Run-time Engine IS required, as well as Drivven's free version of CalVIEW used to run the user interface.  The user interface is not required for normal operation, but may be preferred.  The system is ready to run after the 20 second power-on boot time.   No other products from National Instruments or Drivven are required for this system to operate.  Just provide an external power source from 9V to 30V and connect the encoder inputs and trigger outputs.

These are provided as complete systems, without the need for LabVIEW development tools.  However, application source code is available for customers to make further modifications.  Or Drivven can provide custom application services.

Documentation