Wobbly Raspberry Pi Biped

Posted on 26/07/2013 by mikerr
Modified on: 13/09/2018
Project
Press to mark as completed
Introduction
This is an automatic import from our previous community platform. Some things can look imperfect.

If you are the original author, please access your User Control Panel and update it.

Based on a 6 DOF BRAT clone kit from ebay ($50!) Uses 6 MG995 45g servos: 2 Ankle Servos, 2 Knee Servos, 2 Hip Servos  4xAA Nimh to drive servos 2xAA to drive Raspberry Pi via a cheap "emergency charger" All controlled by a Raspberry Pi using servoblaster software PWM and programmed in python (but might move to C if I need the speed) Still a bit wobbly as I'm not using the knee servos much at the moment. Its interesting that I can get it to walk with just 4 servos in use - so there's an ...


Wobbly Raspberry Pi Biped

Based on a 6 DOF BRAT clone kit from ebay ($50!)

Uses 6 MG995 45g servos:

2 Ankle Servos, 2 Knee Servos, 2 Hip Servos 

4xAA Nimh to drive servos

2xAA to drive Raspberry Pi via a cheap "emergency charger"

All controlled by a Raspberry Pi using servoblaster software PWM and programmed in python (but might move to C if I need the speed)

Still a bit wobbly as I'm not using the knee servos much at the moment.

Its interesting that I can get it to walk with just 4 servos in use - so there's an idea for my next bot ;)

[edit]

My 8 year old nephew Jake thought the bare robot looked boring,

so he drew paper clothes, and added arms and legs:

 

https://www.youtube.com/watch?v=5OQgIfOEktk

also now goes left/right by varying the individual leg's stride length.

I wrote some code for a fast kick:


https://www.youtube.com/watch?v=noObFbkCABU

This runs the knee/hip servos at full speed, instead of slow smoothly interpolated sweeps like used in walking/ leaning

 

E.g.

Servo.hip = 90

Servo.hip= 140 

vs

For sweep in range (90, 140):

          Servo.hip = sweep

          time.sleep (0.01)

I've also moved the battery pack down to the hip for better stability and more torso movement, and can sit down after a long day: 

http://www.youtube.com/watch?v=PEIbgrYKP0I

Next step is to give it some autonomous behaviour (HC-SR04 ultrasonic sensor and/or camera)

Walks and turns, kicks a ball, and sits down !

  • Actuators / output devices: 6x MG995 servos
  • Control method: WiFi
  • CPU: Raspberry Pi
  • Operating system: Raspbian
  • Power source: 4xAA NiMH + 2AA NiMh
  • Programming language: Python
  • Target environment: indoor
Flag this post

Thanks for helping to keep our community civil!


Notify staff privately
It's Spam
This post is an advertisement, or vandalism. It is not useful or relevant to the current topic.

You flagged this as spam. Undo flag.Flag Post