Bipod Control

[John Gutmann]

I am not really sure what thread to put this in. I am starting a new project when I get back from vacation, I want to make a walking bi-pod robot using hobby servos. The uC will be a Atmel AVR ATMEGA16 and to control the servos I will outsourcing to THIS. The servo controller works off of USART and takes 3 commands, start (0xFF) servo # and servo position (0-255).

The actual construction will be relatively simple considering I want to start small then expand once I have this working good. One problem is I am not using a gyro >_<. But it will have several parts, the feet, the lower leg, the upper leg and the platform the controls sit on. This means there is 3 joint per leg which also means that the legs only move on one plane. Part of the control problem is that I don't know a good way to make it turn. I was thinking making the inside step smaller. Also if it matters I will be having 2 switches per foot to know that the foot is flat on the ground.

[bear24rw]

If you want to look at some cool bipods look at www.lynxmotion.com it might give you some ideas...

[[527]phil]

if you search through the pics you'll find the pictures of my Robo one legs. Which is basicly what your describing. I used a BASIC atom control board because it supported up to 20 servos. After i built the legs i found that the servos i was using didn't have enough stall torque to do any real acrobatic maneuvers, so i had it walking for a few weeks and then i put it in my closet until i can afford digital servos (100 a pop) . BTW i didn't use a gyro, you just have to tweak how much you move each servo. And the way i figured out how to make it turn was to stand up and do it myself. easiest way to do it is to pivot on one foot, so while one leg is moveing the other just stands there and the whole thing pivots on that axis.

[John Gutmann]

I was thinking just making one leg step longer than the other like how a car turns (kinda sorta, maybe?) and it would work itself out.

[Nitroxextreme]

Depending on how natural you want it to look.... you could probably make it just keep one leg shuffling on the floor and make the the other take the turning strides.