Duration of activity: 5 hrs
Group members participating: Alexander Rasmussen and Søren Ditlev
Exercise 1
Goal:
To examine the sound sensor
Plan:
Implement a program that display the registered volume and followingly test the sound sensor at different volumes and distances.
Results:
Type
|
Distance (cm)
|
Volume 1-100%
|
Background noise
|
n/a
|
3
|
Light talk
|
60
|
15-25
|
Loud talk
|
60
|
25-30
|
Clap
|
60
|
70-90
|
Light talk
|
120
|
8-17
|
Loud Talk
|
120
|
17-25
|
Clap
|
120
|
55-70
|
Conclusion:
Distance diminishes the volume level. The longer the sound is away from the sound sensor the lower the volume the sensor will registre.
Since most sounds that are human made the varies in volume, for instance a clap varies over 20% at the same distance and even more when distance is factored in, it might be helpful make few clearly defined areas so to lessen the risk of confusing the program.
Exercise 2
Goal:
Log sound data by use of a data logger and identify sound patterns.
Plan:
Implement a data logger. Record clapping sounds a different distances. Graph the data.
Results:
Graph a sound data from claps with a distance of 1m:
 * |
Graph of claps at 100cm distance
|
Graph a sound data from claps with a distance of 2m:
 * |
Graph of claps at 200cm distance
|
Graph a sound data from claps with a distance of 1m:
 * |
Graph of claps at 300cm distance
|
Conclusion:
In a silent environment the claps are easily detectable as shown by the spikes in the graphs above. The distance does not seem to affect the volume of the clap. Probably because the environment was confined. Successful Claps seem to register a volume level between 50 and 90%.
Exercise 3
Goal:
Plan:
Install the program on the system and place the system is a silent environment. Observe how the system reacts to claps.
Results:
The 1st clap starts the system.
The 2nd clap makes the system turn right.
The 3rd clap makes the system turn left.
The 4th Clap makes the system stop.
Exercise 4
Goal:
To make the system stop when the escape button is pressed.
Plan:
Modify the code and test if it works as intended, repeat until goal is reached.
Results:
Conclusion:
By inserting the highlighted sentence into the the while loop the system will stop when the escape button is pressed.
Exercise 5
Goal:
Make the system only react to claps and not loud noise.
Plan:
Implement the method described by Sivan Toledo that detects claps. Adjust the values for clap detection by using the measurements in exercise 2. Test if the system only reacts correctly.
Results:
Conclusion:
By tuning the algorithm using the data from exercise 2 the system almost always register a clap, and never register a continuous loud noise.
Exercise 6
Goal:
Construct a system that turn towards the side which the highest noise is detected
Plan:
First we want to calibrate the two sound sensors, to detect if there is any difference between the them, by measuring the same sound at the same distance, if necessary make adjustments in the code. Next implement code that detects which sensor registers the highest value makes the system turn towards that side.
Results:
Sensor
|
Distance cm
|
volume %
|
Right
|
30
|
11
|
Left
|
30
|
11
|
Link to code [1]
Link to partyfinder video[2]
Conclusion:
The sound sensors did not need calibration as they detect the same values. The System can turn towards the side where the sound is loudest, however the system does turn left slower then it turns right, seem to be a problem with than motors not being of equal strength. The sound source have to relatively close to the sensor inorder for the system to detect the correct side
References:
[3] Exercises http://legolab.cs.au.dk/DigitalControl.dir/NXT/Lesson3.dir/Lesson.html
