Lesson-6.markdown

@@ -10,7 +10,7 @@
 
 ## Goal
 
-The goal of this exercise is to do experiments with Braitenbergs different vehicles. 
+The goal of this exercise is to do experiments with Braitenbergs different vehicle setups. 
 
 ## Plan
 
@@ -18,18 +18,115 @@ The plan is to follow the instructions for Lesson 6 [1].
 
 ## Vehicle 1
 
-### setup
+### Setup
+
+The setup for this exercise refer to Braitenbergs vehicle 1 where two large wheels are mounted on the motors and a small wheel mounted in the back of the car in order to stabilize the construction.
+A sound sensor is mounted in the front of the car pointing forward. The final construction is seen in the following image.
 
 ![Vehicle 1](https://gitlab.au.dk/rene2014/lego/raw/master/Lesson6/Images/Vehicle1.JPG)
 
-### results
+Three implementations will be tested
+
+* **Excitatory** setup with motor power going from 0 to 100
+* **Inhibitory** setup with motor power going from 0 to 100
+* **Negative motor power ** setup with motor power going from -100 to 100
+
+Due the output of the sound sensor span from 0 to 1023 a simple conversion is needed in all cases in order to make the mapping to the motor power with a maximum of 100.
+
+**Excitatory** (0 to 100)
+
+The conversion factor for this case is found by the following equation
+
+*conversion factor = motor power range/sensor range*
+
+Because of the friction in the motor a certain power needs to be applied in order for the wheels to start spinning. By introducing a minimum power into the equation we can ensure that the wheels will spin even at low sounds.
+
+*power = (sound level * conversion factor) + minimum power*
+
+By repeatedly tuning the minimum power we found that a minimum power of 40 was sufficient for this setup. With 40 as minimum power the motor power range is limited to 60 and the equation will therefore be
+
+*conversion factor = 60/1023 = 0.059*
+*power = (sound level * 0.059) + 40*
+
+This is implemented as a function which takes the sound level (0-1023) as parameter and returns the motor power (40-100). The implementation of this is seen in the following code snippet
+
+
+```java
+static int calcDirectOutput(int soundLvl)
+{
+	// Excitatory - 40 is offset to ensure that the motors can be activated
+	return (int)(soundLvl * 0.059f)+40;
+}
+```
+
+**Inhibitory** (0 to 100)
+
+In order to make an inhibitory system with the given setup the output of the sensor needs to be inverted in the following way
+
+*sensor output = 1023 - sensor output*
+
+The conversion factor for this case is found as previously however with no minimum power applied. Therefore equation becomes
+
+*conversion factor = 100/1023 = 0.098*
+*power = (sound level * 0.098)*
+
+The implementation is seen in the following code snippet.
+
+```java
+static int calcDirectOutput(int soundLvl)
+{
+	//Inhibitory - 100/1023 = 0.098	
+	int soundLvlInv = 1023 - soundLvl;
+	return (int)(soundLvl * 0.098f);
+}
+```
+**Negative motor power** (-100 to 100)
+
+For this case when the motors shall be able to spin in both directions according to a linear non-negative output from the sound sensor. This yields that at a sound level of 512 the motors should be at rest with no power applied.
+
+The conversion fractor from previously is used again
+
+*conversion factor = motor power range/sensor range*
+
+The motor power range is now 200 which yields a conversion factor of 
+
+*conversion factor = 200/1023 = 0.196*
+
+To introduce negative motor power 100 is substracted from the calculated output
+
+*power = (sound level * 0.196) - 100*
+
+This is implemented as a function which takes the sound level (0-1023) as parameter and returns the motor power (-100-100). The implementation of this is seen in the following code snippet
+
+```java
+static int calcOutput(int soundLvl)
+{
+	// Exitatory - 200/1023 = 0.196
+	float output = soundLvl * 0.196f;
+	return (int)(output-100);
+}
+```
+
+### Results
+
+
 
 ## Vehicle 2
 
+### Setup
+
+![Vehicle 2](https://gitlab.au.dk/rene2014/lego/raw/master/Lesson6/Images/Vehicle2.JPG)
+
+### Results
 
 
 ## Vehicle 3 
 
+### Setup
+
+![Vehicle 3](https://gitlab.au.dk/rene2014/lego/raw/master/Lesson6/Images/Vehicle3.JPG)
+
+### Results
 
 
 ## Conclusion
@@ -40,3 +137,8 @@ The plan is to follow the instructions for Lesson 6 [1].
 [1] http://legolab.cs.au.dk/DigitalControl.dir/NXT/Lesson6.dir/Lesson.html
 
 ### Videos
+
+[Vehicle 1 - Excitatory] - http://youtu.be/_MwM8BArTkA
+[Vehicle 1 - Inhibitory] - http://youtu.be/M4v3csjxmYQ
+[Vehicle 1 - Negative motor power] - http://youtu.be/2u8VhV_bmUE
+