Lab7.markdown

@@ -164,3 +164,80 @@ For the first experiment with only cruise active, we observed a very simple beha
 
 
 As an addition we tested the robot with Avoid and Cruise active. Here the robot drove straight ahead in a slight curve, ignoring light conditions. When encountering an object with the ultrasonic sensor, the robot compared distances and turned towards the direction where the distance is longest. 
+
+## Exercise 3: Add an escape behavior
+
+#### Task:
+
+In the Figure 9.9 the top priority behavior is Escape. An implementation of Escape in IC is given on page 305 of [2]. 
+
+Implement the Escape behavior in the RobotFigure9_9.java program.
+
+#### Plan: 
+
+We impelemented the escape behavior as suggested by Jones, Flynn & Seiger [3]. 
+
+```
+import lejos.nxt.*;
+import lejos.util.Delay;
+
+class Escape extends Thread 
+{
+	
+	private SharedCar car = new SharedCar();
+	
+	private int power = 70, ms = 500;
+	TouchSensor touchLeft = new TouchSensor(SensorPort.S2);
+	TouchSensor touchRight = new TouchSensor(SensorPort.S3);
+	
+	private boolean bumpLeft;
+	private boolean bumpRight;
+	
+	public Escape(SharedCar car)
+	{
+		this.car = car;
+	}
+	
+	public void bumpCheck()
+	{
+		bumpLeft = touchLeft.isPressed();
+		bumpRight = touchRight.isPressed();
+	}
+	
+	public void run()
+	{
+		 while(true)
+		 {
+			 bumpCheck();
+			 if(bumpLeft && bumpRight)
+			 {
+				 car.backward(power, power);
+				 Delay.msDelay(ms);
+				 car.backward(0, power);
+				 Delay.msDelay(ms);
+			 }
+			 else if(bumpLeft)
+			 {
+				 car.backward(power, power);
+				 Delay.msDelay(ms);
+				 car.backward(0, power);
+				 Delay.msDelay(ms);
+			 }
+			 else if (bumpRight)
+			 {
+				 car.backward(power, power);
+				 Delay.msDelay(ms);
+				 car.backward(power, 0);
+				 Delay.msDelay(ms);
+			 } else 
+			 {
+				 car.noCommand();
+			 }
+			 
+		 }
+	}
+	
+	
+}
+```
+