Penguin is made from micro servos. Probably Penguin was the smallest commercially produced tilt-stride mechanized robot in the world. However, lots of people made big Toddler versions, including ones made by Ken Gracey and David Buckley. One is even as large as a full size human. Smaller than 4-inches? Erco, will you take up the torch and create an "even smaller" tilt stride robot? You might search the archives of the Yahoo Toddler robot group that covered a lot of Toddler variants in many sizes. It should be relatively straight forward to scale down Penguin. Have you thought about a motherboard? What size are the micro servos? Are these from Parallax?
humanoido
Joe Rush built Electra, an 85-pound female tilt and stride robot
over 5-feet tall!
erco: looking at the penguin doc file available on the parallax store page for the bot (in the discontinued section), it looks like the bot is around 4 inches tall overall (including the pcb and stuff stacked on top). The legs are 1.77in long the body is about 2in long and then they overlap some, tack on a smidge for the feet and another .25in or so for the pcb and it's around 4in.
I bet you could make one half that size! [noparse]:)[/noparse]
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Check out the Propeller Wiki·and contribute if you can.
Thanks Roy! Battery size & CG start to become important in these small sizes. I'm going minimalistic and lightweight. But not this minimalistic: http://www.youtube.com/watch?v=F7HPy2lnWVQ
The Penguin has proportionally much shorter legs than the older Toddler, probably for stability. But the Penguin's feet barely get off the ground. I actually prefer the Toddler's gait, since the feet lift higher, the body leans more, and it looks much more dramatic overall. Many variables to play with.
Humanoido has a tremendous Penguin video at http://www.youtube.com/watch?v=9owSIXhh_Mo that shows some amazing (possibly sped up?) walking/sliding/traversing motions. Nobody does it better!
Anyhow, I may not go much smaller than the Penguin, but I'll have longer legs and go for more lean. But not quite THIS far... http://www.youtube.com/watch?v=oHf0QiIUleU That's painful to watch, ouch.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
My Penguin video is NOT increased in speed. You are seeing the real time motions with no changes to the video process. Also, regarding the comment about the feet going barely off the floor - I would say you can program it for much higher foot motion. You can see a very good example of this in the program "SHAG WALKER" where Penguin lifts its feet up much higher than the smooth surface gait, so as not to snag the feet in the carpet.
Programming Penguin is pure fun and joy - there are many effects you can get from software coding. I expect those servos you have can do a great job. The key is to establish the range of motion and not exceed it when the processor starts resetting due to low battery voltage. I would simply remove or disable the brownout circuit on the Stamp or Propeller to avoid this reset condition.
I will make some comparison measurements of the servos in a Penguin to the servos listed at the ebay link you provided, in the next post.
The Penguin's stock servo from Parallax is a GWS servo, Naro/std, made in Taiwan, and stamped CE on the back. It is often referred to as a micro servo. In the Parallax Penguin manual download, the servo is part number 900-00014 and described as "Grand Wing Naro standard servo."
I measured a servo removed from a Penguin and compared it to the China Shenzen 2x3.7g Mini Micro AA RC plane helicopter Servo. You can see the most space gained is 8mm. Based on the Penguin design, there is no servo to motherboard clearance at the top, and the feet have 31mm from the stride linkage to the floor.
Erco: About those walking/sliding/traversing motions that you noticed - there's a lot that can be accomplished with just two servos. In one example, software code is written to create a third virtual servo to gain extra motions. Although it seems to vibrate in one direction, it's actually a controlled mechanical harmonic motion from the virtual servo VS. There's a lot more descriptive detail in the code comments and the original code postings. There are other effects programmed into Penguin, such as embedded ramping up or down, stationary mechanical oscillators, tappers, and various displacements. I think a smaller robot can make similar motions, although the coding parameters will change.
You can make a much smaller toddler robot by placing the tilt servos in the legs and tilting the feet as seen below (and driving the stride from the tilt).
Looking at the Penguin/Toddler design, you can also make the legs go higher and put the stride servo at the top, and lower the tilt servo and linkages. There are other ways to tilt. You may want to eliminate the tilt linkages altogether and use a direct drive and spring for economical reasons.
Sweet info, thanks Humanoido! As ever, you are tireless and relentless in your pursuits of robotic perfection. I'll digest that info as I experiment and start building my walker.
I'm sure my cheap China servos are lower quality than the stock Penguin units. Your video is most impressive, especially those high-speed harmonics that enable that amazing side slide traverse. Very cool! That's gotta be hard on the servos, mine might break doing that! As of now, my goal is slower, dramatic walking action, so my servos should be up to that task. The fact that I will be using lightweight plastic instead of aluminum should lighten dynamic loads, too. Currently planning to use either 3 or 4 N or AA cells to power everything, have to see what works best and longest for the weight.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
Thanks for the kind words Erco. Glad to help. As far as I know,
servos driven out of range due to those random or low power
resets (read about brownout protection on the BASIC Stamp)
can cause the most damage, or mechanical binds and blockages.
As you mentioned, it's a good plan to start with slow simple walking
and small ranges of tilt and stride. Actually, developing some small
tilt code and then stride code is a good prerequisite. One program
for Penguin is named Small Walker where its development followed
that process.
For some applications, Small Walking can improve the accuracy of
movements and traction on inclines with software only. In one
project, aiming the IR pair was used to make a nice (and free)
Penguin inclinometer with Small Walking.
About harmonics, I never had a servo go bad from a harmonic VS
program. Inside the NARO servos, tiny gears have plastic cogs
that seem quite durable. However, a cheaper servo could
disintegrate if the plastic is brittle.
Recapping, use Shag Walker for taking big steps, and Small
Walker for taking small steps.
Small Walker gives Penguin the ability to walk by taking small
steps. Designed for smooth surfaces without irregularities, it increases
stability of walking on slight sloping plane surfaces without the use of
an inclinometer.
The smallest Penguin-style robot existed before Penguin existed. A good friend of mine John Olson and I had a little contest "who can build the smallest walking robot?" He produced the Pocket Walker and I made Penguin. John has amazing engineering skills and tools, yet he's one of those guys who doesn't hang out on forums like the rest of us. I can thankfully blame him for helping us choose all of the right manufacturing equipment at Parallax.
Anyway, I think he beat me by a half inch and six months. I sent John an e-mail and asked him to post a photo of Pocket Walker in this thread.
I never got an original Penguin I look forward to seeing the new design.
I like the info here http://www.bluebelldesign.com/AppMod2.htm·on the Home Center Walker. Since I missed the original Toddler too - I always had this as a back-up plan.
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
To really appreciate the Pocket Walker, you have to see it in action. It doesn't walk like the Toddler or Penguin do. But it does shift its weight. Please see the following video.
Neat alternative walking motion on that Pocket Walker! Looks like the raised foot just barely clears the ground as it moves forward.
I built a pretty cute pseudo-walker a while back out of an inverted trash can. "Moving along on square wheels" was my inspiration. Not small, but it had an interesting lumbering gait, plus "Sprint mode". I'll post a vid soon.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
erco said...
I built a pretty cute pseudo-walker a while back out of an inverted trash can. "Moving along on square wheels" was my inspiration. Not small, but it had an interesting lumbering gait, plus "Sprint mode".
erco, what has your master-mind dreamed up this time?! Really?? A walking garbage can with square wheels??? It sounds very unique and a good way to carry out the garbage - let the walking garbage can do all the work! Can the can find its way back from the garbage dump area? I look forward to seeing some pics and vid.
It'll be a while before I dig it out and get it "walking" to make a video. I have a Cessna to sell this week (anybody need a 152?) and that needs some detailing...
Anyhow, no it's not a trash hauler, just a funny little bot. I started with a nifty new plastic·trash can (bought 2 and can't find'em anymore, shoulda bought a dozen) as a lightweight, durable robot body. Just an IR·remote-controlled show bot. I'm putting every cheap electronics gizmo in it: talking wristwatch, wireless TV camera, tons of LEDs, a one-motor clarm (my newly-coined word for claw/arm), etc.
I used triangular wheels (square was just for inspiration) that alternately go left/right. They auto-index at 120 degrees, pretty cool.
Here's an OLD video just showing some LEDs and bogus sensors spinning. See the Knight Rider, B9·& Robby influence?
If it were a 172, I'd be interested. You need four seats because you always find a lot of new friends when you get a plane.
Jim
erco said...
It'll be a while before I dig it out and get it "walking" to make a video. I have a Cessna to sell this week (anybody need a 152?) and that needs some detailing...
Just took a couple pics of my walker next to the Penguin. Ken - I can see I should have put the batteries on the back to make it short. I have a really great video of this thing walking, if I can just find it. I'll keep looking. Thanks to Chris for finding the one on YouTube. ...Tiger
Here is another little bot you guys might find interesting. This is one Ken has never seen! It's a lot smaller than the Penguin and has six servos for pretty fluid motion. The controller pcb goes on the top but is off in this picture. I have a piece of plastic on the top to keep it rigid right now. You can see the 300mah LiPo located under the controller. It's light weight and has plenty of power for all the servos. The linkage on this prototype is a combination of machined and laser cut. I was always going to injection mold those parts to make this easy to duplicate, but never got around to it. The servos are 5g Tower Pro's (less than $3.50 from hobbypartz.com).
Comments
Penguin is made from micro servos. Probably Penguin was the smallest commercially produced tilt-stride mechanized robot in the world. However, lots of people made big Toddler versions, including ones made by Ken Gracey and David Buckley. One is even as large as a full size human. Smaller than 4-inches? Erco, will you take up the torch and create an "even smaller" tilt stride robot? You might search the archives of the Yahoo Toddler robot group that covered a lot of Toddler variants in many sizes. It should be relatively straight forward to scale down Penguin. Have you thought about a motherboard? What size are the micro servos? Are these from Parallax?
humanoido
Joe Rush built Electra, an 85-pound female tilt and stride robot
over 5-feet tall!
Might just have to make a little walker.·How tall is a Penguin robot? Do you have a scale diagram showing the leg length & pivots?
FOR W0=180 TO 1100 STEP 2
PULSOUT 15,W0 '·· 180 ccw· 1100 cw
'PAUSE 20
DEBUG DEC W0,CR
NEXT
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·"If you build it, they will come."
I bet you could make one half that size! [noparse]:)[/noparse]
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Check out the Propeller Wiki·and contribute if you can.
The Penguin has proportionally much shorter legs than the older Toddler, probably for stability. But the Penguin's feet barely get off the ground. I actually prefer the Toddler's gait, since the feet lift higher, the body leans more, and it looks much more dramatic overall. Many variables to play with.
Humanoido has a tremendous Penguin video at http://www.youtube.com/watch?v=9owSIXhh_Mo that shows some amazing (possibly sped up?) walking/sliding/traversing motions. Nobody does it better!
Anyhow, I may not go much smaller than the Penguin, but I'll have longer legs and go for more lean. But not quite THIS far... http://www.youtube.com/watch?v=oHf0QiIUleU That's painful to watch, ouch.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·"If you build it, they will come."
My Penguin video is NOT increased in speed. You are seeing the real time motions with no changes to the video process. Also, regarding the comment about the feet going barely off the floor - I would say you can program it for much higher foot motion. You can see a very good example of this in the program "SHAG WALKER" where Penguin lifts its feet up much higher than the smooth surface gait, so as not to snag the feet in the carpet.
Shag Walker is available here in a zip file with other walking programs:
www.p-robot.com/index.php/navigation-and-movements.html
Programming Penguin is pure fun and joy - there are many effects you can get from software coding. I expect those servos you have can do a great job. The key is to establish the range of motion and not exceed it when the processor starts resetting due to low battery voltage. I would simply remove or disable the brownout circuit on the Stamp or Propeller to avoid this reset condition.
I will make some comparison measurements of the servos in a Penguin to the servos listed at the ebay link you provided, in the next post.
humanoido
Post Edited (humanoido) : 6/3/2010 6:23:56 AM GMT
www.parallax.com/Portals/0/Downloads/docs/prod/robo/27313-6%20PenguinDoc-v1.4.pdf
I measured a servo removed from a Penguin and compared it to the China Shenzen 2x3.7g Mini Micro AA RC plane helicopter Servo. You can see the most space gained is 8mm. Based on the Penguin design, there is no servo to motherboard clearance at the top, and the feet have 31mm from the stride linkage to the floor.
www.parallax.com/StoreSearchResults/tabid/768/txtSearch/servo/List/0/SortField/4/ProductID/488/Default.aspx
cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180399101188
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humanoido
*Stamp SEED Supercomputer *Basic Stamp Supercomputer *TriCore Stamp Supercomputer
*Minuscule Stamp Supercomputer *Tiny Stamp Supercomputer *Penguin with 12 Brains
*BASIC Stamp Supercomputing Book *Three Dimensional Computer *StampOne News!
*Penguin Tech *Penguin Robot Society *Toddler Humanoid Robot Project
*Ultimate List Prop Languages *Prop-a-Lot *Propalot Stuff *Prop SC Computer
*Prop IB Hypercomputer - under development *Hobby Space Program
humanoido
Post Edited (humanoido) : 6/3/2010 9:23:20 AM GMT
Looking at the Penguin/Toddler design, you can also make the legs go higher and put the stride servo at the top, and lower the tilt servo and linkages. There are other ways to tilt. You may want to eliminate the tilt linkages altogether and use a direct drive and spring for economical reasons.
humanoido
http://forums.parallax.com/showthread.php?p=912128
It's a modified Toddler robot made into a humanoid. Humanoid Toddler HT may give you some ideas for your new robot.
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humanoido
*Stamp SEED Supercomputer *Basic Stamp Supercomputer *TriCore Stamp Supercomputer
*Minuscule Stamp Supercomputer *Tiny Stamp Supercomputer *Penguin with 12 Brains
*BASIC Stamp Supercomputing Book *Three Dimensional Computer *StampOne News!
*Penguin Tech *Penguin Robot Society *Humanoid Toddler Robot
*Ultimate List Prop Languages *Prop-a-Lot *Propalot Stuff *Prop SC Computer
*Prop IB Hypercomputer - under development *Hobby Space Program
I'm sure my cheap China servos are lower quality than the stock Penguin units. Your video is most impressive, especially those high-speed harmonics that enable that amazing side slide traverse. Very cool! That's gotta be hard on the servos, mine might break doing that! As of now, my goal is slower, dramatic walking action, so my servos should be up to that task. The fact that I will be using lightweight plastic instead of aluminum should lighten dynamic loads, too. Currently planning to use either 3 or 4 N or AA cells to power everything, have to see what works best and longest for the weight.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·"If you build it, they will come."
servos driven out of range due to those random or low power
resets (read about brownout protection on the BASIC Stamp)
can cause the most damage, or mechanical binds and blockages.
As you mentioned, it's a good plan to start with slow simple walking
and small ranges of tilt and stride. Actually, developing some small
tilt code and then stride code is a good prerequisite. One program
for Penguin is named Small Walker where its development followed
that process.
For some applications, Small Walking can improve the accuracy of
movements and traction on inclines with software only. In one
project, aiming the IR pair was used to make a nice (and free)
Penguin inclinometer with Small Walking.
About harmonics, I never had a servo go bad from a harmonic VS
program. Inside the NARO servos, tiny gears have plastic cogs
that seem quite durable. However, a cheaper servo could
disintegrate if the plastic is brittle.
Recapping, use Shag Walker for taking big steps, and Small
Walker for taking small steps.
You can download the Small Walker code here, in a Zip file:
www.p-robot.com/index.php/navigation-and-movements.html
humanoido
Post Edited (humanoido) : 6/3/2010 5:52:57 PM GMT
Anyway, I think he beat me by a half inch and six months. I sent John an e-mail and asked him to post a photo of Pocket Walker in this thread.
Edit: just found the link www.wildrobots.com/pocketbot.htm
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Ken Gracey
Parallax Inc.
Follow me at http://twitter.com/ParallaxKen for some insider news.
Post Edited (Ken Gracey (Parallax)) : 6/3/2010 6:29:20 PM GMT
I never got an original Penguin
I like the info here http://www.bluebelldesign.com/AppMod2.htm·on the Home Center Walker. Since I missed the original Toddler too - I always had this as a back-up plan.
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
Post Edited (Whit) : 6/3/2010 11:36:15 PM GMT
http://www.youtube.com/watch?v=PsML3gz1Zfk
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Chris Savage
Parallax Engineering
·
I built a pretty cute pseudo-walker a while back out of an inverted trash can. "Moving along on square wheels" was my inspiration. Not small, but it had an interesting lumbering gait, plus "Sprint mode". I'll post a vid soon.
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·"If you build it, they will come."
humanoido
Anyhow, no it's not a trash hauler, just a funny little bot. I started with a nifty new plastic·trash can (bought 2 and can't find'em anymore, shoulda bought a dozen) as a lightweight, durable robot body. Just an IR·remote-controlled show bot. I'm putting every cheap electronics gizmo in it: talking wristwatch, wireless TV camera, tons of LEDs, a one-motor clarm (my newly-coined word for claw/arm), etc.
I used triangular wheels (square was just for inspiration) that alternately go left/right. They auto-index at 120 degrees, pretty cool.
Here's an OLD video just showing some LEDs and bogus sensors spinning. See the Knight Rider, B9·& Robby influence?
http://www.youtube.com/watch?v=u1Qo1_uF8CE
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·"If you build it, they will come."
If it were a 172, I'd be interested. You need four seats because you always find a lot of new friends when you get a plane.
Jim
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·"If you build it, they will come."
Post Edited (Tiger) : 6/6/2010 11:52:34 PM GMT
...Tiger
Post Edited (Tiger) : 6/6/2010 11:45:40 PM GMT
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·"If you build it, they will come."