The Drivven Combustion Analysis Toolkit (DCAT) is a unique LabVIEW plug-in for creating sophisticated in-cylinder combustion analysis and logging applications for engine research and development. The included examples can be used out-of-the-box for building stand-alone systems, or modified and integrated with engine control applications. Using DCAT, engineers can streamline engine R&D by using built-in functions for Next-Cycle and Same-Cycle Control. DCAT leverages the latest hardware from Drivven and National Instruments for engine position tracking and synchronization of data-collection and processing. DCAT is also packaged in a fixed-executable, called µDCAT, and paired with USB-based DAQ devices for portable, low-cost combustion analysis, starting at $8,995.
DCAT Brief Features
- Supports NI R-Series, S-Series, M-Series and CompactDAQ
- Simultaneous engine-synchronous and time-based data acquisition
- Concurrent data monitoring and streaming to disk
- Many channel configuration, calibration and filtering options
- Common pegging and cylinder data alignment options
- Multiple pressure metrics and heat release calculation techniques
- Engine noise and knock analysis
- Engine sync from encoders or production engine trigger wheels
- Built in functions for Next-Cycle and Same-Cycle Control
- Insert custom analysis blocks for unique test and control applications
DCAT Data Flow
The data flow path of the DCAT software is shown below. Data is collected at different rates through PXI S-series cards, M-series cards or cRIO modules, and then passed to the real-time controller. This raw data can be consumed by three simultaneous processes. First, when requested by the operator, the real-time controller can stream all raw data to disk for later post-processing on a PC. Second, the data can be processed continuously for filtering, cylinder alignment, pressure metrics, heat release, statistical analysis and other reductions to be visualized on the host PC and stored to disk in a summary file for further post-processing. Third, critical data can be selected from the DAQ stream for use in Next-Cycle Control.
DCAT stores data and all configuration parameters in an open and efficient LabVIEW binary file format called TDMS. These files may be transferred from the real-time controller to a host PC and analyzed using post-processing utilities included with DCAT. The TDMS files may be opened within custom LabVIEW applications or Excel to generate reports.
Next-Cycle and Same-Cycle Control
Feedback control is made available in DCAT as Next-Cycle or Same-Cycle Control. Next-Cycle Control is processed in the PXI RT controller, whereas Same-Cycle Control is processed within the FPGA. Common uses of Next-Cycle Control are online feedback to stabilize engine conditions, or as a calibration aid to quickly move between set points. For example, 50% burn location can be controlled by modifying start-of-injection timing. Same-Cycle Control calculates incremental sub-crank-angle-degree heat-release in the FPGA. This information is available for making control decisions within nanoseconds. Examples of Same-Cycle Control are manipulating inter-pulse delay for diesel injections, and misfire detection and spark restrike for SI applications.
DCAT Example Systems
With 1 MS/s aggregate throughput, the µDCAT USB-6251 is ideal for low channel count, high sample rate systems
The µDCAT cDAQ4 provides 100 KS/s/ch simultaneous sampling for eight channels with room to customize
Base Cost: $8,995
With five spare slots, the µDCAT cDAQ8 not only supports simultaneous-sampling combustion analysis, but also knock-calibration and a wide variety of medium-speed I/O
Base Cost: $9,395
DCAT Base System
NI’s PXI RT Controllers, S-series simultaneous sampling, and FPGA reconfigurable I/O cards form a solid foundation for a high-speed combustion analysis system
DCAT System with SCXI DAQ
The addition of SCXI low-speed DAQ, a second S-Series card for time-based sampling and cRIO modules for specialty I/O make a more complete integrated test cell DAQ system
DCAT System with Engine Control
The addition of Drivven automotive I/O modules turn the DCAT base system into a full authority engine controller capable of Next-Cycle Control
DCAT System with Engine Control and SCXI DAQ
Our most popular system combines all features of full authority control and test cell DAQ into a complete package
DCAT System Selection Guide