What it's going to do remains a secret, but the video's will show its purpose quite well, have a look! I build it with Lego Technic, the electronics are built by myself: a lot cheaper and more flexible than the NXT platform ;)
The robot is driven by four XL motors and has a compressor unit with two pumps (handpumps) which are driven by two M motors. The pneumatic system pushes down a set of wheels, so the robot can move also sideward (see video). The pneumatic system will also be used for the grabber.
Next to install is a set of NXT motors, which will move the grabber to the right position.
It's not yet finished, but this is what it looks like right now:
video for obstacle challenge:youtu.be/eXrUMmAvH1Q
video for moving sideward with caterpillar tracks:youtu.be/kw4tAIRt_lY
video for indoor navigation (go to the fridge, to the living room and back):youtu.be/NY1oa62qi5w
If you have any suggestions and/or comments: please let me know!