noizeramp

Aleksey's programming, engineering and electronics log

Quadropod - Walking

by Aleksey Gureev
30 September 2019

Short record of the first baby steps. Woo hoo!

Now this is how it works. I took an excellent article on quadruped robot movement by Josh Elijah as the basis. Although he describes the position of legs and transition in details, he doesn’t give any examples of the actual angles computation functions. It’s understandable. Each bot may have a different configuration of joints and number of segments. The idea, however, persists.

So I ran through my trigonometry books and came up with own functions. They work pretty fast, but a tad not enough to make transition smooth when you need to move all 4 legs at once. This is where I plan to start using a pre-calculated move matrix.

If you have a look at the pictures in the Josh’s post, you’ll notice that every leg basically has three final positions. These can be pre-calculated and saved for quick lookup. In my case every position will be addressed by the angles of three servos. So it’s not going to be a huge lookup table after all.

I was trying to see how this decision fits the idea of having side moves and turns as the next step, but can’t figure just yet. We’ll see.

Happy making!

tags: diy - quadropod

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