SOFT DB - Signal Ranger DSP Board


	DSP Division \| Products \| Distributors \| Services \| Applications \| Support \| Site Map

DSP Division \ Products \ ElectroAcoustic System \ ZEN : 3-CH Active Control System


		Home


	DSP DIVISION

Products

DSP/FPGA Development Board (OEM)

DSP Programmation tool : Simulink to SR-Converter software

ElectroAcoustic System

TENOR : 8-CH Datalogger Acquisition System

ALTO : 2-CH Spectrum Analyzer

ZEN : 3-CH Active Control System


	ACOUSTICS DIVISION


	SOUND MASKING DIVISION

ZEN Active Control System : A wideband 3 Channel X-LMS

A powerful, easy-to-use, compact and low cost controller

Main Features

6 inputs (3 reference signals, 3 error signals) and 3 outputs for the control signals
Real-Time X-LMS feed-forward with filtered references and a LMS optimization
Wideband control up to 36 kHz on three channels simultaneously
Interaction between each channel take into account (coupled mode) or not (non-coupled mode)
Up to 30 dB of noise reduction (wideband applications) and up to 60 dB of noise reduction (narrow-band applications)
A friendly PC user interface which allows to adjust the algorithm parameters and to analyze the control results

Application Fields

The ZEN Active Control System is ideal for acoustic and vibration applications.

Easy-to-Use Controller

The Zen Active Control System unit can be controlled via a friendly PC user interface. The High-Speed USB-2 connection allows to set the parameters of the controller, but also to see in real time the different signals and filters of the system.

A Powerful Compact Controller

The Zen Active Control System provides enough power to allow a precise wideband control. For example, with a sampling frequency of 15.6 kHz, the controller can optimize in real time:

992 coefficients for the non-coupled mode
290 coefficients for a coupled mode case (assuming 400 coefficients for primary and secondary control paths

Cost Effective

Based on the powerful but cost effective SR-MK2^TM DSP board, the ZEN Active Control System is suitable for research laboratory requirements, but it is also ideal for industrial and commercial applications. Specific version of the ZEN Active Control System can also be provided as an OEM product.

Details of the Control Algorithm Running on the DSP

The X-LMS optimization is done in real time for a selectable sampling frequency up to 78.125 kHz.
In coupled mode, the secondary control cross-paths are taken into account during the LMS optimization.
In non-coupled mode, the control system acts like three separate mono-channel controllers.
The Reference signal Rx(n) can be filtered by an adjustable high-pass to remove the DC component of the signal.
The Error signals Ex(n) can be filtered by an adjustable high-pass to remove the DC component of the signal.
Adjustable pass-band or low-pass filter on the reference and Error Signals to force the control on a specific spectral zone.
Normalized adaptation step size Mu
White noise (W.N.) generator can be added to the reference signals for greater control stability.

Note:

Wx	:	Control filter x
CxEy	:	Filter of the secondary control path between the control output x and the error sensor y
CxRx	:	Filter of the primary control path between the control output x and the reference sensor y
Normx	:	Function for the normalization of the adaptation step. The normalization is done with the energy of the filtered reference.
LMS_x	:	Optimization function (LMS) for the control filter x.

Technical Specifications

Hardware:

- 3 inputs for the reference signals with an adjustable gain (0 to 54 dB)
- 3 inputs for the error signals with an adjustable gain (0 to 54 dB)
- Software selectable Electret microphone input or direct input
- Direct input dynamic ±20V
- Microphone input dynamic ±2V
- 3 outputs for control signal (dynamic ±2V)
- Very low group delay: 0.4 ms
- USB 2.0 link
- Metal box: 28 x 21 x 8 cm

PC Interface Specifications:

- User friendly PC interface for setting the controller and analysing the control results
- Automatic control paths identification module
- Easy-to-use module for designing the pass-band filter applied on inputs
- Scope and frequency analyzer allowing the spectral analysis of any signal of the control system
- Real-time control filters observer
- Real-time estimation of the noise reduction on each channel
- Useful export functions for reports and further analysis
- Built-in analysis module

X-LMS Algorithm

- Adjustable frequency span up to 39 kHz (with real-time optimization)
- Selectable coupled or non-coupled mode
- Primary control path compensation
- White noise generator for stabilization of the control filter coefficients
- Real-time normalization of the adaptation step for the LMS algorithms
- Pass-band filter on all inputs to force the control on a specific spectral zone
- Real wideband controller : for instance, at 15.6 kHz, the controller can optimize up to 290 coefficients
(coupled mode) and 992 (non-coupled mode)

Documentation

Zen user manual