Let's Make Robots!

Bipedal Chair Progress - NOT FINISHED YET!

Bipedal Human Transport

VIDEO!!!

Well, video is up.  I dont show anyone sitting on it because I'm the only person who knows how to controll it and I had to shoot the video, so I just let it walk solo. Enjoy :]

BTW at the end one of the neighbors is like "whats that?"  so I, (almost startled) say "um...robot" and the video ends...

 

 

June 5, 2009 Update:

Well I never could get a video...yet.  I'm doing some repairs and upgrades today, and rebuilding the control box.  WITH ANY LUCK it'll stop raining here and I can shoot a video on our new, flat, and level driveway ( hehe :] ).  I must say however that I am disapointed at how ugly it truly is...especially compaired to this: http://basicrobotics.net/mech.html

WOW I need that thing... I'm seeing an expensive new project coming in the next few months.....

But I'm not done yet.  These actuators are AMAZING.  I'm going to figure out how to build a more efficient, better looking frame with whatever money I can save up.  Then just transfer the actuators, and bam, WIN.

QuickUpdate:

OK the brand new batteries already died.  I put a 10 amp car fuse to regulate the amps, too.  I have an 18 volt drill battery on it (6 volts more than supposed to) and it still walks frustratingly slow.  You can't even tell its walking on video.  But on the good side, I made an brilliantly designed way of controlling it without anything more than tape, wires, tin foil, glue, and a box.

Here it is (It has 1 big switch for back and forth motion, two for independent side control to recalibrate, and one master cut-off switch):  I know its hard to make it out, its very complex and immaturely built, plus lighting is bad.

PHTO0033.jpg

 

 

UPDATE3:

It walks!  I am sooooooo happy!  My actuators came today, and I've been pondering forever on how to get it all together safely...  And it all paid off.  Test 1 was a 50% sucess, because the wheels gave in to the twisting motion of the legs.  Tests 2 and 3 were 90% sucess, because it walks, but it walks backwards (although technically I never even defined a front or back yet, seemg how its a square...)

It held my weight, and walked flawlessly.  I will post a video tomarrow!  Thanks for sticking with me!

 

 

UPDATE2

Ok, sooo close.  I have the money.  I finished the frame.  Now I just need the actuator.  I found a pair of cheap, 250 lbs actuators, 85 lbs stronger than the last one I chose.  In less than two weeks I'll have it done and walking...

 

I also updated specs.  Instead of a rechargable battery, I chose alkaline.  It's cheaper, as my budget is shrinking.  The new actuators are 250 lbs now, not 165.  There are also no sensors like I had planned.  And my idea to put 10 amp fuses on it probably won't happen, because the actuators only can go up to 5 amps.  So that's it, stay tuned for more...!

 

 

PHTO0028.jpg

 That's my dog Abby on the latest frame.

 

 164202176_tp.jpg

The new actuator model, capable of 250 lbs.

 

 

 

 OLD:

Side View

PICT0042.jpg

 

Front View

PICT0041.jpg

 

Extended View

PICT0044.jpg

 

This is the first side of my "Mech"

 It's hard to make out the shape chair yet because I only have 1/4 the parts so far... this project will be completed probably early May, but I'll update in the meantime.

 

This chair dubbed TP (or TS) is a walking chair, as in you sit i it and it walks (bipedal).  Here's the CAD model of the final design:

untitled.jpg

 

Neat, huh?

 

 

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the fuse is a good idea, no doubt, but the fusebox designed for this actuator is not cheap.  i may just build my own though, i'll think it all over

toy robots with the same kind of "walk" usually has wheels that can only roll forward. This make sure that one leg remains stationary while the other pushes forward. With free running wheels, one foot will roll backwards while the other rolls forward, then they'll both run back to their starting position before repeating again in opposite order for the other step.

The solution used in the toys I've disected are variations of this:

wheelbrake.jpg

The cogwheel is mounted on the same axle as the wheels underneat the foot. When the cogwheel rotates counter clockwise, the red arm just slides on top og the "teeth". But when you try to turn the cogwheel clockwise the red arm will get stuck against the first cog/tooth it encounters.

K.I.S.S. 

The technical term for that is ratchet. But you may be describing the function of a freewheel.

Yes, I've seen that.  in fact, my earliest bipeds used that.  This new robot uses a similar technique.  a metal bar like below with rubber or something slides along the ground.  Then when it backs up, it sticks into the ground, allowing the other leg to move forward.  I couldn'y make the "rachet" (that rik said it was called) strong enough for 200 lbs.

 

 biped.jpg

I tried to 'Keep It Super Simple"  but I think this is pretty good.  It is an outdoor targeted robot.  And my tests have shown that this would work on coarse surfaces like carpet, cemet, asphalt, etc.

 

That thing looks awesome! I hope it works.

thanks!  i'll post a video of my latest progress ASAP!
What kind of actuator mechanism do you plan to use for the tilting ancles?

nope, no tilt anymore.         

after some thought i fugured a robot this big would have a good chance of breaking if it tilted, because my first attempt (which i never posted) failed totally, and i wanted to be sure that this one works just right

 

it has wheels on the feet so that they can glide over serfaces more easily as if the foot was off the ground.

i'l be finishing it next month, so I'll post a video within a few weeks at most.

 

 

Cool idea to use a diagonaly mounted actuator.

But how do you intend to lift the foot of the ground? with your current mechanical setup you wont get any forward motion. There mus be some sort of mechanism to move the entire weight over to one foot while the other foot is lifted up and swung forward. -Or am I misunderstanding, again? (it's not that uncommon)

well, here:

untitled_1.jpg

hows that?