In November 2008, I wanted to participate at the Eastern Canadian Robotic Games with a Lego robot. Out of all competitions, I wanted to do something new, so I chose Search and Rescue. The purpose is to build a remote controlled robot and guide it through a maze like play field to rescue a small Teddy bear. Wall-E being a popular subject at the time, I thought I should give it a shot and build my own version out of Lego.
The robot uses 2 Motor Amplifiers from Hitechnic to drive 2 RC buggy motors from a 9V battery box. The motors have a good torque and manage to drive the treads well enough. The head is built around the Ultrasonic sensor (also from Hitechnic) and a regular light sensor. I was hoping that I could eventually program the robot to go autonomously, but never finished it. The arms extend and drop down to the floor to grab the Teddy bear and bring it on the trash compartment lid. The head pans and I can adjust the tilt angle so the robot can detect the objects using the Ultrasonic sensor. The problems I had with the robot was the size too close to the distance between the walls and it was hard to navigate and turn in the maze. Also, the Teddy bear they had was a bit smaller than mine, so the robot could not grab it properly. But the kids loved it and we all had a good time at the Games!
Here are some pictures at different building stages: