Excitation

It is for now possible generate different kind of signals as a sine wave, a linear chirp and an exponential chirp as defined by the function

@staticmethod
def set_excitation(SIGNAL_TYPE, A, t, *F):
    if SIGNAL_TYPE == 'Sine':
        signal = np.sin(2 * np.pi * F[0]* t)
    elif SIGNAL_TYPE == 'Linear Sweep':
        alpha = (F[1] - F[0])/t[-1]
        signal = np.cos(np.pi * alpha * t**2 + 2 * np.pi * F[0] * t)
    elif SIGNAL_TYPE == 'Exponential Sweep':
        beta = (np.log(F[1]) - np.log(F[0])) / t[-1]
        signal = np.cos(2 * np.pi * (F[0] * np.exp(beta * t) - F[0]) / beta)
    return  A*signal

Acquisition

Acquisition is a bit tricky right now because of the synchronization between the input signals and the output signals. It is not yet resolved and to avoid that problem, it is recommended that the input device has one channel of reference.

After starting the software you will first be presented with the detection of the turn table. A dialogue box will open telling you all the hardware is set up correctly. Then you will see the main window of the application with the audio settings, file settings and measure settings to start the measures.

Audio settings

selecting both the input and the output device for the measure and the number of channels, the time of acquisition is needed at the right of the screen as represented here

You can then choose a signal of excitation as described above for a frequency band of your choice. Silent time frame is the time for windowing the excitation signal.

Apply settings and you can move on to the file settings.

File settings

Here you can select the path for your measurement. Once selected, just apply Set Path and move on to the measure settings.

Measure settings

Now select your measure name and angle step for the rotation of the turn table

At the end of each measure, the software will automatically generate a .wav output file with respect to the measure name and the angle step of the measure as for example

"0deg_MeasureName.wav" .

So choose carefully !

Each of the .wav generated will contain as many channels as selected previously.

If you're all set, apply Start !