Angle Domain Processing

LMS Test.Lab Angle Domain Processing supports in-depth analysis of engine or reciprocating machinery data as well as correlation of this data with possible noise or vibration issues. It provides an automated or interactive tool for time data conversion to angle data and for correct angle data alignment with the system duty cycle. Individual channels can have different offsets, so that data from multiple cylinders can be processed at the same time. Multiple averaging, tracking and/or triggering strategies support data processing for any stationary or semi-stationary operating condition, while system transients can be analyzed over user-definable data segments. An extensive list of cycle statistics can be processed within user-definable gates of interest, so users can investigate e.g. the evolution of peak-cylinder acceleration values and the corresponding piston impact angle within the system operating cycle. 

The LMS Test.Lab Angle Domain Processing solution provides angle domain analysis synchronized with the system’s operating cycle in parallel to narrowband data analysis. Angle domain analysis can be done for stationary or transient operating conditions, supporting engine run-up-run-down analysis, or engine start-stop analysis respectively. Data acquisition can be performed on any LMS SCADAS front-end, and supports all available signal conditioning. The LMS SCADAS Mobile front-end supports input from incremental encoders with up to 200 kHz pulse rates, while intelligent tacho conditioning supports immediate correction of missing or double pulses.
Via the customized metrics calculator, users can easily enter advanced application-specific calculations like e.g. valve bounce, valve lift, etc. for valve train dynamic testing. These metrics will then be calculated in the same processing run. Data can be displayed in different formats or the X-axis can be changed instantaneously to measured tachos or slow parameters to improve correlation insights. Results can be visualized using intelligent displays that provide transparent coupling of results with underlying data, enhancing the engineer’s task for root-cause analysis.

Taking the pain out of piston NVH testing

There is certainly no shortage of available NVH measurement and analysis techniques to study engine noise and vibration issues. The global market is full of tools and homegrown techniques to nail the root cause of many engine noise and vibration annoyances, such as engine knock, piston NVH, valve tapping and gear rattle. Most of these are related to the engine duty cycle – specifically, forces exerted by particular components during the intake, compression, combustion and exhaust cycle steps.


Renault engineers rely on detailed testing for cleaner and greener engine design

Managing this immense quantity of data associated with valvetrain performance testing is a challenge in itself. To do this, Renault uses LMS Test.Lab and the LMS SCADAS Mobile hardware acquisition system. During the tests, the LMS system can even check the operational behavior of the running valvetrain on the test bench to make sure that it continues to operate ideally without deformation or breakage.