Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: ZacAttack on January 25, 2009, 02:20:46 PM

Title: i need a bit of help!
Post by: ZacAttack on January 25, 2009, 02:20:46 PM
hi, i am thinking of building a hexapod autonomous robot, but befor i buy the parts i need to know if i can do somethign, aand how to do it,   i want to make the robot be able to find and follow motion, so it would follow me or someone else walking by. i would really apreciate any help i coudl get.
Title: Re: i need a bit of help!
Post by: want2learn on January 25, 2009, 03:11:50 PM
Use a camera with Blob tracking as far as I understand.

The problem with walking robots is that generally even the fast ones are pretty slow and would struggle to keep up with whatever they are following, unless its another walker (or a half dead snail ;D)
Title: Re: i need a bit of help!
Post by: Jdog on January 25, 2009, 06:03:38 PM
You could use a sharp ir sensor and the stampy algorithm. If I understand you correctly, you want the robot to be motionless until it detects motion and then you want to follow it. To do this, you would put the whole stampy algorithm in an if loop and have the loop compare the last two readings from the sharp ir and if they are different, then there is motion. This would be much much cheaper than using a camera ($20 compared $200) but the only downfall would be that it might accidentally get caught on a wall or something, but again it's $180 cheaper.
Title: Re: i need a bit of help!
Post by: ZacAttack on January 25, 2009, 06:29:43 PM
thanks, and for speed, it woudl only need to keep up with a person, hmmm, im not sure how to do the algorithum :/
Title: Re: i need a bit of help!
Post by: HDL_CinC_Dragon on January 25, 2009, 07:57:48 PM
typically walkers cannot keep up with a persons normal walking gait...

The stampy algorithm that Jdog is referring to is a piece of code from the Stampy robot project:
http://www.societyofrobots.com/robot_sumo.shtml
Title: Re: i need a bit of help!
Post by: ZacAttack on January 25, 2009, 08:25:08 PM
thanks, and it would still be slow but i was goign to make it move 3 legs at a time, with longer legs to carry it a bit further faster
Title: Re: i need a bit of help!
Post by: HDL_CinC_Dragon on January 25, 2009, 08:32:10 PM
3 legs at a time is pretty much the only way to do it lol. Longer legs means longer body otherwise the legs would run into each other and cause problems.
Title: Re: i need a bit of help!
Post by: cosminprund on January 26, 2009, 02:04:12 AM
Also longer legs require stronger servos.

@ZacAttack, are you going to buy an hexapod kit or are you planning on building it from scratch? I wanted to make an hexapod but realised I'm not able to make the mechanical bits and I'm not sure I want to buy an kit - for me the fun's in building, not assembling :)
Title: Re: i need a bit of help!
Post by: ZacAttack on January 26, 2009, 06:15:09 AM
i was going to buy the frame and most of the joints, but use my own servos, buy my own battery, servoboard, i think im giong to use a basic stamp, basicallly, im going to buy the chassi frame, and find exsisting metal joints from other websites, and find all my own electronics.
Title: Re: i need a bit of help!
Post by: ZacAttack on January 26, 2009, 04:03:52 PM
cuz yah, buildig from a kit is kindof pointless