Customer Solutions

Digital Signal Processing Board Created for Education with LabVIEW Finds Time in a Commercial Instrument

Author(s):

Bruno Paillard, Universite de Sherbrooke

Industry:

University/Education

Product:

LabVIEW, Signal Conditioning

The Challenge:

Developing an embedded signal analyzer for an instrument to measure acoustic material properties.

The Solution:

Using LabVIEW-based software to control a specialized digital signal processing board that takes the measurements and pre-processes the data.

Mecanum is a company that specializes in acoustic material testing and modeling. They completed the development of advanced equipment used for the full characterization of open-cell poroelastic materials, and they planned to integrate an embedded signal acquisition and analysis board to replace the commercial signal analyzers they had been using.

At about the same time, the Electrical and Computer Engineering department at Université de Sherbrooke began the production of Signal Ranger, a Digital Signal Processing (DSP) board created to teach microprocessors and digital signal processing at the undergraduate level. The Signal Ranger features a fast fixed-point digital signal processor, as well as a large number of analog I/Os, suitable for a wide variety of vibration, acoustic, or control applications. A comprehensive set of LabVIEW-based software tools is included with the board, greatly facilitating code development. (Further Technical information can be found in the article "Digital Signal Processing Board Created with LabVIEW Provides Great Tool for Education" by Bruno Paillard.)

Mecanum selected the Signal Ranger as the embedded signal acquisition and analysis board to use in the development of their equipment for the full characterization of open-cell poroelastic materials.
The designed equipment, named the PoroVerse system, encompasses five measurement modules, managed by the specialized PoroVerse software. The system is linked to a laptop computer through a universal serial bus (USB) port. They use each of the modules to characterize a specific set of properties.
In this context, they use the Signal Ranger board to completely manage an acoustic test and a vibration test. More specifically, it performs signal generation, acquisition, filtering, pre-processing, and automatic gain control. A personal computer performs the spectral analysis using a LabVIEW application, which also provides a very natural user interface.

Together with its DSP code examples and LabVIEW interface, Signal Ranger provided a complete low-cost solution within three weeks of the start of the project. The development included the specialized acquisition and DSP pre-processing code, as well as a "host" LabVIEW application to control the tests and process and present the results.

Two factors greatly accelerated the development of this component of the PoroVerse system:

• Because a LabVIEW interface existed for the board we could use LabVIEW for the development of the host application. Furthermore, this interface retains the look and feel of a standard LabVIEW instrument driver, which facilitates integration for experienced LabVIEW developers.
• The availability of a very complete analog I/O driver and code examples at the DSP and LabVIEW levels.

Compared to using a simpler acquisition board, or a complete commercial signal analyzer, Signal Ranger provided the possibility to integrate automation at the board level (automatic gain control, calibration management, etc.), and also the possibility to perform signal filtering and pre-processing in real time at the board level.

For more information, contact:

 Bruno Paillard, Ph.D.

Electrical and Computer Engineering Faculty of Engineering

Université de Sherbrooke

Sherbrooke, Quebec, Canada, J1K 2R1

Tel: (819) 821 8000 x2138

E-mail: bruno.paillard@gel.usherb.ca

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