Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: humanrobo on April 29, 2008, 02:50:40 AM

Title: Walking RObots
Post by: humanrobo on April 29, 2008, 02:50:40 AM

hi i am new in building robots. What i should do if i want to make the humanoid robot walk and balance when walking? how many DOF is needed.
i will be glad if someone can help thanks.
 

Title: Re: Walking RObots
Post by: benji on April 29, 2008, 09:27:02 AM

i suggest you make a simpler walking type robot if its your first robot to build
human walk is somthin pretty complicated
consider the movement of the surface of your foot when you walk,, when you mount your foot on the floor,,
see how it bends?haa?  thats not cuz it looks just cool, its a management of your body weight to go slowly on the foot
,,plus,, ou should balance yourself on 1 foot whiole the other is moving,,,
lots of hard stuff to handle,,,good luck

Title: Re: Walking RObots
Post by: Steve Joblin on April 29, 2008, 09:57:58 AM

Here are some great plans for a first step into walking robots... http://www.bluebelldesign.com/AppMod2.htm (http://www.bluebelldesign.com/AppMod2.htm)

Title: Re: Walking RObots
Post by: humanrobo on April 29, 2008, 07:32:13 PM

ok thanks for the help guys :D

Title: Re: Walking RObots
Post by: humanrobo on April 29, 2008, 07:35:17 PM

hi again, which motor is better for humaniod robot legs? the stepper or the servos?
i am still quite confusing about the link that is posted by steve.

Title: Re: Walking RObots
Post by: benji on April 30, 2008, 02:59:06 AM

i think both are possible, here things depend on how big is the whole body so you know how much torque u need.
if you'd go with steppers then try to get small step size ones to provide smooth turns.

the thing in human walking robots is more than just move and stop
there is smoothing the motion,,how?here it is
first the bot should raise its foot and that should happen slowly
when its totally in the air you can start to move it faster as its safe there to move it faster
when landing which is the toughest part you need to slow things down and your landing should be pretty well studied.
maybe a PID for these velocities control,?? ,

good luck
lets see your project when its done

Title: Re: Walking RObots
Post by: Trumpkin on April 30, 2008, 06:11:56 AM

I think u should use digital servos.

Title: Re: Walking RObots
Post by: humanrobo on May 01, 2008, 07:10:51 PM

the actual robot size is aorund 1.3m and the legs i am doing is about 70 cm.So should i use servos?
i am new in robotics and my research on servos motors are limited, do u have any links that tell u more about servos and thier connection?
this is a project that we have to do in school in groups.
btw thanks for the infos. :)

Title: Re: Walking RObots
Post by: benji on May 02, 2008, 02:42:10 AM

the body is relativly big , adn even if its alaminium it would be heavey for a hobby servo to push
or you should search for high torque servos
just do the math and youll choose a motor with suitable torque.. and its always better to get a motor with torque more than you need.
there is a servo motor tutor in this website

http://www.societyofrobots.com/actuators_servos.shtml (http://www.societyofrobots.com/actuators_servos.shtml)

Title: Re: Walking RObots
Post by: Admin on May 03, 2008, 06:13:18 PM

I recommend starting with a simpler robot - first learn the basics, then the advanced, in that order :P

You can always reuse parts and code for the biped robot later, so it wouldn't be a waste of time/money.

I recommend reading these tutorials:
http://www.societyofrobots.com/toparticles.shtml

Title: Re: Walking RObots
Post by: humanrobo on May 04, 2008, 06:51:15 PM

i will read the infos u guys gave, really glad that u guys are helping me
Thanks! :D