Combine previous labs and add following a line. Your robot is to follow a line (down the center of the robot), following my robot that is also following the line (staying within 2.5-3.5 robot lengths of me). If it runs over a stop sign (i.e. red), it should stop. If someone runs into it form behind, it should sound the alarm, spin around (180 degrees) and stop.
Details
The "leader" follow the same black line and vary its speed slightly
Parts
You will need an ultrasonic sensor on the front
You will need a color sensor in the "middle" of your robot pointing down.
You will need a touch sensor on the back of your robot facing out.
Use a block to follow the line
Use a block to adjust the speed (and a variable)
Use a block to react to the touch sensor being pressed
Use parallel programming to deal with the color sensor to stop the robot.
Challenges
Have the display constantly update the min. and max. distance encountered between you and the leading robot.