The beauty of PCs in the test and measurement world is their ability to bring processing power out of the lab and into diverse environments. Consider measurement of the pressure, strain, and acceleration placed on an automotive instrument panel when a passenger side airbag is deployed. In the past, engineers used high-speed cameras for this task. However, the camera can only show what takes place outside of the instrument panel housing the airbag. Using a laptop PC, high-speed analog measuring devices, and custom software, Roush Industries was able to develop a fast, cost-effective system to measure what takes place inside the panel before the airbag is visible.
The system had to be fast, portable, and user-friendly, and it had to provide a high channel count. To help meet those goals, a lightweight, portable National Instruments SCXI-1000 chassis comes with four SCXI modules. Data from the SCXI-1000 is digitized and transmitted to a laptop via a DAQCard-6062E that samples at 500 ksamples/s.
Designed for use by a computer novice, the software is intended to be passed around to many different users and must be easy to run with just the help of a user manual. The software code used to set up and control the hardware, as well as view and process recorded data, was written in LabView 6.1. This software platform was chosen because of its easily programmable icon-based code and its easy integration with National Instruments hardware.
After the data on the airbag deployment is collected, the post-processing application is designed to view and report the pressure data in a specific format for input into different commercial computer-aided engineering software packages. The recorded data, along with the location setup information, is used to extrapolate and interpolate the data across the area of the car door throughout the duration of the deployment. That data is then plotted on a 3D graph for viewing.
Using an ordinary laptop PC and National Instruments software and hardware, information about passenger-side airbag deployment is now easily measured and recorded. Additionally, this data is converted into a format that can be read directly into a computer-aided engineering model. In this way, engineers can make safer, faster airbags in less time and with more efficiency than ever before.