Portable Real-Time Vibration Monitoring System

Author(s):
Bipin M. Kanth - Captronic Systems, Pvt. Ltd.

Industry:
Automotive

Products:
CompactRIO

The Challenge:
Developing an application for on-line monitoring and datalogging of random vibrations experienced by automotive test components in a randomly vibrated test bench and thus studying the effects of vibration on different automotive components.

The Solution:
Implementing real-time 3-dimensional vibration monitoring system using the NI CompactRIO reconfigurable control and acquisition system and the unprecedented flexibility of NI RIO technology.

The automotive component manufactured is subjected to random vibration to study the behavior of the component before the product releases.

The system provides accurate real-time analysis to study the effect of vibrations on the component. The vibration analysis was previously done offline with limited online monitoring and analysis provision. Hence, the user had to work with small chunks of data repeatedly at pre-selected intervals missing crucial failure points. The storage of the test results for the entire duration of the test process facilitates easy offline analysis.

Software Implementation

We divided software implementation into the following modules:

• Real Time Acquisition
• Real Time Floating Point Operation and Datalogging
• Offline Data Analysis

Real-Time Acquisition

After receiving a start signal from the serial terminal LCD display panel, the system determines the space available in the compact flash of real-time controller cRIO-9002. If the size is not sufficient, an indication is sent to the serial terminal LCD display so that the data can be copied to laptop/PC before continuing with the test. If the space is sufficient for logging, acquisition begins. The cRIO-9233 samples voltage signal transmitted from the IEPE accelerometer and transfers the data to the real-time controller cRIO-9002.

Real-Time Floating-Point Operation and Datalogging

The real-time floating point operations include determining RMS, peakpegel value, and FFT for each block of data consisting of 4096 data points. The peakpegel value is used to eliminate accidental peaks in the acquired vibration data this is determined using a proprietary algorithm. The RMS and peakpegel values are logged throughout the entire duration of the test with a fixed interval of 5 minutes. The duration of test is up to 150 hours. The FFT is logged once during the first five-minute interval, during the last five-minute interval, and according to user configured intermediate intervals. The user can configure the intermediate interval according to the run duration.

The calculated parameters RMS and peakpegel value is also transmitted to the operator panel and updated every second. The operator can thus monitor the vibration level experienced by the component during run and determine if the vibration level is within expected limits.

Offline Analysis

The GUI provided on the laptop allows the user to carry out offline analysis for already completed tests.

The sequence of operation is as mentioned below:

1. Select required test data
2. View offline data
3. Generate report

The FFT, peakpegel and RMS plot are displayed. FFT is displayed on plots shown on left side of the screen and peakpegel and RMS are displayed on the plots shown on the right side of the screen.

There is provision to zoom each of the screens by double clicking on the required plots. The zoom screen has provision to further zoom selected portion of the plot.

After selecting the required test data and viewing the waveform, an option is provided for the user to generate reports of the waveform viewed by clicking on the generate report button.

The generated report contains information about the operator, component tested, the model number, serial number of accelerometer used, and the intended customer details along with the RMS, peakpegel value and FFT plots of the component during the test duration.

The portable real-time vibration monitoring solution provided a customized and convenient means of performing vibration analysis compared to the costlier and bulkier vibration analyzers available in the market. It provided a reliable and rugged solution using the capability of NI RIO technology combined with the flexibility of LabVIEW. The system offers real-time analysis of vibration thereby facilitating immediate corrective action in case of failure of component. It saved the user six to eight hours per component that needed testing at 30 percent of the cost of available analyzers.

For more information, contact:

Bipin M. Kanth

Captronic Systems, Pvt. Ltd.

Koramangaka, Bangalore, India

Tel: 91-080-25535046

E-mail: BipinM@captronicsystems.com

 

Browse All Case Studies »