Society of Robots - Robot Forum

General Misc => Robot Videos => Topic started by: georgeecollins on January 13, 2012, 12:45:04 PM

Title: Quad Slalom
Post by: georgeecollins on January 13, 2012, 12:45:04 PM
I have been working on the gaits of my quadruped, Quokka.   Here is a test I did where it avoided obstacles and then knocked them over for fun. 

http://youtu.be/zK9tRcsXpdU (http://youtu.be/zK9tRcsXpdU)

I'm still learning about building quads but I think that in general I don't really like these crab style legs for a quad.  It seems like for quads and for bipeds a better design is to have the legs move mostly on one plane underneath the robot like a horse or a dog.  Anyway, I keep experimenting with code and calibration so hopefully I will learn to do this better. 
Title: Re: Quad Slalom
Post by: Gertlex on January 13, 2012, 01:15:20 PM
Nice assembly.  What happens when it walks on carpet? :)

I'm still learning about building quads but I think that in general I don't really like these crab style legs for a quad.  It seems like for quads and for bipeds a better design is to have the legs move mostly on one plane underneath the robot like a horse or a dog.  Anyway, I keep experimenting with code and calibration so hopefully I will learn to do this better.

Why do you think that method is better? For forward movement?  It's definitely worse for turning movements, from what I've seen.

To get your quad moving forward faster, you probably need a different foot design instead of the single point of contact that each foot currently has on your bot.
Title: Re: Quad Slalom
Post by: georgeecollins on January 14, 2012, 01:46:57 AM
With a 2:2 gait it is hard to get good clearance for a carpet.  You can do better with a 3:1 gait but it is slower.  I can definitely clear carpet with a 12 servo quad with the legs underneath. 

This robot is much more in the test phase, but I think this is the way I want to go: 

http://youtu.be/FEiQ4TqQSZk (http://youtu.be/FEiQ4TqQSZk)

You are right that turning is harder but there are ways to deal with that, the easiest is to add more servos.  There are a lot of things I want to try.   In general any time you have feet that are wide turning is a problem.