During our first year, we made use of standard Ev3 hardware to build your robot. It made use of two color sensors to follow the line as well as one LEGO distance sensor to detect obstacles and the walls in the evacuation zone. When rescuing victims, the robot drove around until it hit a wall and then lifted up its claw to get potential victims into the container on top of the robot. After a few iterations, the robot would search for the black corner to unload potentially saved victims.