With the use of ultrasound the LEGO Mindstorms EV3 & NXT Ultrasonic sensors could detect the distance to an object. You can use it in many different ways most of them very interesting and fun. Some of them a little more challenging, but rewarding.
The GorillaBot walks on its two arms, using two large motors as forearms. It also has this awesome head, which actually is pretty useless as an ultrasonic sensor, unless you lift its eyebrows.
A turtle robot with 2 sensors- ultrasonic and gyro, capable of following her course and navigating through anything. Just don't annoy it, or it will hide in its shell or even come and bite you.
We love bears. These are great creatures. Do you know that the Polar Bear is the largest bear there is.
This robot was first constructed years ago for some of the first classes in LEGO Mindstorms Robotics that we held. It is quite challenging, but nevertheless very rewarding when completed and when you manage to program it to walk. Check it out.
This robot is part of the category of robots called animals. After following the building instructions you would have a frog that could jump. Of course, the jump depends on the surface and the friction between the robot and the ground... quite complex physics involved. But if you program it to move forward it will try to jump and it is your job to try to make it jump higher.
You could try to extend some of the legs, for example.
Building instructions for a LEGO Mindstorms animal that looks like a Penguin, and walks like a penguin and if you program it, it will even talk like a penguin. Can you program it to talk like a penguin?
Build from LEGO EV3 Core and Expansion set this robot looks like a scorpion. The Scorpion strikes, when it sees a pray with the ultrasonic sensor and you can use the touch sensor and the rotation sensor to control the spike movement. It has a scissor mechanism at the back using a system of gears and levers.
Again a LEGO animal. This time it looks like an ant. It's interesting that this robot has no wheels and moves in a way very different from the rest of the "wheel robots".
There is much to be learned about mechanics from the way animals move. Ants are a good example. In the real world, an ant could carry a load of 20x its mass. It would be interesting to see how much load could this robot carry? Try it.