Project 1

Sound detection with a real e–puck

Jean-Baptiste RazurelGaétan Maechler

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Plan

1. Problematic

2. Methodology

3. Results and discussion

4. Conclusion

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Introduction

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Material 2 e-puck robots.

• One emitter

• One receiver

A robot has 3 microphones (see Figure 2) and a speaker

Goal => The explorer robot has to find the emitter

Figure 1 : e-puck robot Figure 2 : Position of

microphones

3

Problematic

• How does the explorer recognize the emitter robot?

• How does the robot know the direction of the sound and move towards it?

• The sound is known as a wave thus some parameters can be calculated !

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Problematic

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Figure 3: Sound wave problematic

5

Methodology

• Make a clear soundUsing Matlab a 500 Hz signal is created. A signal sound wave at 500Hz should be better to analyze than a voice containing many frequency. But the output is not very musical!

• Record it using microphones

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• Is the main frequency corresponds to

500 Hz?

• Raw signal received by the explorer

with 256 samples => some noise is

present!

Figure 4 : Raw sound

signal

6

Methodology

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Methodology

• Results of the Fourier transform

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Figure 5 : Amplitude versus Index of

FFT

• Check if some peaks

corresponds to the

theoretical index

• The experiences told us

that the peak is at 10 and

not 8.

8

Formulas used

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How does it move ?

With the phase

difference we can

know which of the two

microphones hears the

sound first

=> The robot moves in

that direction

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Figure 6

Theta values

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Figure 7

Calculate the sound direction

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Dance of the e-puck

We used IR0, IR1, IR6 and

IR7

Spinning around and switching LEDs

ON

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Figure 9

Limits

• Obstacles

• Long distance

• Noise due to open

environment

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Conclusion

• The e-puck reacts to the sound and reach it

• The code can be improved to make the robot movements more smooth

• Obstacle avoidance can be a further step in this project (with an analysis of the intensityof the sound)

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References

• Generated by Doxygen 1.5.4, e-puck Reference Manual 1.0.

• X.Raemy (SWIS group EPFL), Introduction to the e-puck robot.

• http://www.e-puck.org

• http://www.mathworks.ch/ch/help/matlab/ref/fft.html

• http://fr.wikipedia.org/wiki/D%C3%A9phasage

http://www.gifetgif.com

http://www.gifgratis.net

http://www.quincyma.gov

http://jeffshore.com

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