Walking Robot Part 1

So motion.....what is motion? Well I guess it is movement of an object or organism. Walking is a lot more complex that I would have guessed. Who knew that walking could be such a mess. Balance becomes the biggest issue. Then of course you hit the obstacles of transferring rotational energy into a different kind of energy. But you can achieve movement with rotational energy. But rotational energy is simplest in some ways. The other way to simplify the matter is to do swimming. Water is much more forgiving about movement, balance is barely an issue for movement. But alas, our robotic parts tend not to fare too well in water.

Enough of my ramble, last week my partner and I started dreaming up ideas of "walking" robots. First we started to sketch out ideas. First off, let me state that my sketching abilities are abysmal at best. Moreover, my creative ideas are well pretty unimaginative and boring too. Aka, I'm about the worst possible partner you can get for this kind of job. So I started by thinking of my favorite animals, or when that failed, about any animals that had different methods for movement.

I first thought of manta rays and how they fly through the water. I realized of course that actual flight through air would be next to impossible given the materials at hand and my abilities to harness them. So I figured, hey water is much easier to fly through. That inspired this sketch below:

I tried drawing the manta ray from several different perspectives to help me identify the different parts that would comprise a manta-bot. Then I seperated it into these parts. It was a very basic design of two wings and a body that were connected somehow. The wings would flap up and down and the body would house the engine that powered the flapping. Simple & effective. Of course since this would be in water, it would HARDLY be simple. Occam's razor -- anything that can go wrong will go wrong!

This is another sketch of a manta-bot 2. In this case I was thinking of adding on a tail that would also help propel/power the manta-bot. Again a very simple creation of a triangular tail connected to a body. But then I thought, hey, why even have wings? Why not just use a tail like a dolphin's tail? So this now evolved into dolphibot.

But here I started to think through the design flaws inherent in my two bots so far, the up/down motion of the tail or the wings had to be slightly angled, otherwise the robot would stay in one place in the water....Now that would not be impossible to do, but it would change the design a bit.

So I came up with design number 3, another marine inspired organism:

The jellybot. Now the jelly bot was barely sketched out before it was officially canceled. But at least it was a new type of motion...no longer a simple up/down flapping but a contracting and expanding of a hemisphere. Of course, I realized that the transfer of this idea of motion to reality would far exceed my capabilities. Here you see then our gorilla inspired robot, happily named gobot. Gobot really goes on the simple idea of 1/2 moving appendages that rotate fully and pull the gobot forward. Here is my partner's version of the gobot.

 

We were thinking of trying to make this robot climb stairs! I'll write more on the gobot in a sec.

 

Now this design is based off of my partner's idea of creating a frog. The idea was that the two front flippers would move in a circular motion with little paddles at each end, while the back flippers would form a more complicated movement based off of the breast stroke kick. Here is another drawing of this idea made by my partner:

 

PS It's really easy to who can actually draw in our group :)!

So after our froggity started to come to shape, we thought it might be helpful to make a quick lego model out of it so we could better understand the different mechanisms at work for the back legs. Here is a picture of this model out of legos!

 

this just shows one back leg completed. What we found was that this wasn't the easiest idea. But then we started looking at some of the models already made in the room. We came across the row boat model built by the robotics course in '07. They had created a mechanism for angleing the oars and constraining the rotation of the oars. We realized that we could use this in our design. But then my partner talked to Lyn and he didn't seem all that excited about the prospect of the row boat design as it had been done ad nauseum last year.

So we moved on to other concepts. Our final idea was the dog robot, also called the pupot. Now pupot is the personal pet of my partner. She has been working on this idea with loving care. Here is her amazing drawing of this idea:

She wants to create the rythm of the dog walking motion that is 1234 where the right front leg goes first then the back left leg. It is a diagonal alternating leg motion. Since we are limited by two motors the conception of pupit is difficult in the extreme. My partner is working on the foam model of this robot.

Now here is gobot redrawn by yours truly. Gobot here is being influenced heavily by the inch worm movement, leading me to rename this to gowot. I changed the idea to have 4 stationary legs that would provide balance for gowot. Then it would have two arms up front that would rotate fully and drag the gowot along.

 

So here is the model I started with before making my foam model.

 

And when I actually built the model, I realized that there was nothing wrong with adding another two dragging legs to the back of gowot. This is all there is for now! Lot's of thinking and lots of hurdles :).