INTRODUCTION

TigerANC-II is a standalone active controller without the need of a host PC. All control parameters can be set through an embedded touch screen where the control status also can be viewed. The hardware mainly includes a high-end float-point DSP, which is in charge of the core control algorithms, and an ARM chip, which is in charge of the human-machine interface. The controller also benefits from the ultra-low latency of AD/DA conversion, which makes it possible to realize a compact ANC system for many latency critical applications.

OVERVIEW

Fig 1. TigerANC-II

TigerANC-II is an off-the-shelf equipment which can help users establish an active noise control (ANC) system efficiently with other peripheral devices provided by Antysound. TigerANC-II supports either wideband or harmonic noise active control. For wideband noise control, TigerANC-II supports up to 16-channel centralized control and 9-channel decentralized (mono-channel) control. For harmonic noise control, TigerANC-II supports up to 16-channel centralized control with reference input from accelerometer or tachometer.

TigerANC-II is designed in 3U rack unit, which makes it easy to be mounted in a 19-inch rack. The detail size information of the chassis of TigerANC-II is depicted in Fig. 2.

Fig 2. Detail size information of the chassis of TigerANC-II

Upper: the size information of each side of the chassis

Bottom: the size information of the L-shape holder (as denoted by 3 in the front panel) for mounting the chassis in 19-inch rack

SPECIFICATIONS

1. Size

As depicted in Fig. 2.

2. Weight

6.3 Kg

3. Number of Channels

l 18 analog input channels (reference + error)

l 16 analog output channels

l Up to 9 reference signals (from software generated signals or from analog input channels)

l Up to 16 control signals

4. Harmonic noise reference generator

For harmonic noise control, the fundamental frequency of the target noise source can be measured (with an optional reference signal generator board) and the harmonic reference signal can be generated accordingly.

5. Adaptive Algorithms

l Gradient descent feed-forward control using the FXLMS algorithm (wideband control)

l Harmonic noise feed-forward control algorithm (harmonic noise control)

6. Control Filter Types

l FIR (wideband control)

l Harmonic noise filter (harmonic control)

7. Maximum Tap Length for Control Filters

Depends on the number of channels used

8. Adjustable Algorithm Parameters

l Cancellation path number

l Cancellation path transfer function taps

l Cancellation path identification signal strength

l Cancellation path identification stepsize

l Control filter number

l Control filter taps

l Control filter stepsize

l Control filter leakage coefficient

9. Cancellation Path System Identification

l Adaptive FIR model with random noise as the excitation signal (wideband control)

l Harmonic noise as the excitation signal (harmonic noise control)

10. Sampling Rates

l There are 10 choices of sampling rates varying from 125 Hz to 64 kHz, with optional anti-aliasing low-pass filter

l 3 kHz (harmonic noise control)

11. Input and Output Filtering

The white noise generated by the internal signal generator can be high-pass, low-pass and band-pass filtered with 10 pre-defined different filters. Users can load their own filter parameters through a USB flash disk.

12. Analog Inputs

l Signal maximum is 10 Vpp

l AC coupled inputs

13. Analog Outputs

l Signal maximum is 5 Vpp

l AC coupled outputs

14. Signal Generator

l 6 sine wave generators

l 1 white noise generator

l Frequency range 0 Hz to 32 kHz

l Generator signal can be set as the sum of the white noise and different sine waves

15. Saving Data

System data can be saved to a USB flash disk

16. Signal Display

l Identification signal level

l Modeling error level

l Reference signal level

l Error signal level

l Cancellation path filters

l Control filters

17. Cables

Customized coaxial cable is recommended. For environments with strong electromagnetic interference, customized double-shielded cable is recommended.

NOTES

Both the wide band and the harmonic noise control algorithms can be customized. For details, please contact sales@antysound.com.

APPENDIX 1. Schematic diagram of a wideband noise control system as requested by the customer (3 reference sensors, 4 control sources and 9 error sensors)