CARoLINE Acoustic test on mechatronic assemblies · use in development, test and series production · synchronous recording of up to 4 channels · I/O resources for triggering, gate control and synchronization · standard interfaces for integration into complex production lines / End-of-Line testing systems · comprehensive visualization and analysis functions · monitoring option of acoustic data recording using headphones · offline version to create / edit test sequences with the help of simulated measurement data
Transcript
CARoLINE Acoustic test on mechatronic assemblies
· use in development, test and series production· synchronous recording of up to 4 channels· I/O resources for triggering, gate control and synchronization· standard interfaces for integration into complex production lines / End-of-Line testing systems· comprehensive visualization and analysis functions· monitoring option of acoustic data recording using headphones· offline version to create / edit test sequences with the help of simulated measurement data
Impact sound analysisExamination of function and assembly quality of electromotive vehicle components
Analysis of vibration and natural frequency of electro-powered motor assemblies
Insulated recording of the UUT against external sound and vibration
Mounting of impact sound sensor magnetically or by spring force
Recording of NVH data (Noise, Vibration, Harshness) by the CARoLINE system
Test of assemblies in different operational states and load modes
Recording of signals for analyzing noise (e.g. engine rev) parallel to NVH data
HardwareCore of the hardware architecture is a measurement data acquisition card, which records the impact sound signal through a 16 bit A/D converter with a sampling rate of 44,1 kHz. The inputs of the card are connected to the channel set to signal conditioning. Such a module has a second sensor interface, to which a reference sensor for calibration of the measuring channel can be con-nected. In addition to analog and digital I/O resources for synchronization and gate control of data recording, motor power supply of the UUT is passed through the signal conditioning module. The drive speed is determi-ned from the current ripple, which is a prerequisite for data analysis in form of order analysis. Alternatively, Hall signals from position transmitters can be used for speed calculation.
To build up multi-channel acoustic analysis systems (up to four measurement channels possible) multiple data acquisition cards are integrated. The measurement recor-ding is synchronized with the help of a trigger bus (RTSI).
The headphone module allows monitoring of the recorded acoustic signals for an individual evaluati-on of the UUT. The headphone module can play two measurement channels; playback can be switched between mono and stereo operation. CARoLINE provides standard interfaces for remote (Ethernet or RS232-C) so that integration into higher-level complex function systems or system controls is possible.
Piezoelectric sensors with integrated IEPE-/IPC amplifiers are preferably used for NVH recording. The power supply for the sensors is provided by Channelset. It is possible to switch off the supply to the Channelset module so that, if necessary, other measurement transducers such as microphones can be connected.
Depending on the nature of the UUT, the impact sound sensors can be mounted magnetically or by spring force. When using the acoustic analysis system in automated production lines (end-of-line test) the positioning of the impact sound sensor needs to be acoustically decoupled from the base frame of the test equipment.
For characteristic sounds like buzzing, creaking etc. individual software modules are available which store analysis functions, filter combinations and parameters for optimal detection of each acoustic characteristic. To create individual test sequences, these modules can be accessed from the library, parameterized according to the inspection task and compiled into a complete test sequence. Also customized definition of characteristics is possible by a graphical user interface which allows se-lection and parameterization of analysis functions. The same kind of input masks are available for the configu-ration of control variables and trigger conditions.
Possible trigger sources are:
· level of incoming impact sound · threshold values of analog inputs · state change of digital inputs · order of the higher-level system via host interface · predetermined time interval
The evaluation of the results is carried out in parallel during a program run for data recording. Every 100ms a complete block of evaluated data is created, which is visualized in the user interface. The operator can choose between time or position-dependent presentation (e.g. displacement or rotation angle of a drive).
Following analysis functions are available:
· rotation speed determination from Hall signal or current ripple
· order analysis · automatic tolerance band creation based on a defined number of test items
· statistics function, graph of dispersion
The evaluation of recorded NVH signals as Pass/Fail de-cisions is based on so called analysis indices. Exceedan-ces of predefined tolerance band are evaluated accor-ding to their height and duration. The user defines the maximum analysis index for the UUT to being passed.
In addition to the online evaluation of incoming data, CARoLINE offers the possibility to archive measure-ments in raw data format. Therefore simulated data for creation and optimization of test procedures are availa-ble in the offline version of the system without requiring data acquisition hardware.
Preparation, execution and evaluation of noise analysis
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