Author Topic: CAD of my newest robot (Read 69713 times)

garriwilson · « **Reply #30 on:** March 02, 2008, 01:02:42 PM »

I'd be slapping myself around if I lost 35$.

How come the other HS-225MG didn't fry?

Admin · « **Reply #31 on:** March 09, 2008, 07:06:22 PM »

Quote

How come the other HS-225MG didn't fry?

That my friend is a $35 question (I have no idea).

Another quickie update:

I just replaced every screw on the robot . . . I don't like hex anymore, now using phillips 4-40 screws. Took me an entire hour to do it . . . the screw count, if I counted correctly, is 94 screws

The balance on the robot is still kinda bad . . . same problem I mentioned a long time back . . . I'm gonna find my other caster and just add a second one.

Lastly, the wiring is sooooo messy! The wire count is like ~140+ and not everything is even hooked up yet . . . and despite my efforts to keep it organized its still really bad. I'll have to replan it out in the next iteration.

Also made progress on programming the CMUcam . . . but its still not working yet. I decided I'll get a different camera soon, either AVRcam or maybe CMUcam2 . . . because the orginal CMUcam has a serious software bug preventing it from working outside in sunlight.

Admin · « **Reply #32 on:** March 23, 2008, 11:02:09 AM »

The long awaited update!

Actually, originally I was holding off to show you guys a better demo, but then I realized the ERP fundamentally will never be finished. Its experimental, I'm changing it all the time . . .

Anyway, another motion test video:
[youtube]V7v_RbRINLw[/youtube]

(the servo on the left arm is still fried, but you can't tell)

I put some effort into documentation here, with a few new pics:
http://www.societyofrobots.com/robot_ERP.shtml

Code for the version that used the $50 Robot controller, for those that want it:
http://www.societyofrobots.com/downloads/ERP_ATmega8_old_code.zip

And lastly, I uploaded here two CAD images of the newest version I am working on. It uses the new Blackfin camera, has an extra caster for balance, and I evil-fied the gripper

I should be making and assembly the new parts this week.

airman00 · « **Reply #33 on:** March 23, 2008, 11:03:31 AM »

put a plastic (or real) sword or a gun on that thing !

ed1380 · « **Reply #34 on:** March 23, 2008, 11:35:56 AM »

wow that thing moves fast. are those regular speeed servos?

Admin · « **Reply #35 on:** March 23, 2008, 11:59:29 AM »

Quote

are those regular speeed servos?

As I mentioned earlier:

Quote

5) Most servos won't break if you reverse voltage, however one of my HS-225MG servos went up in smoke . . . literally tons of smoke. A wasted $35 My other HS-225MG, four of my HS-311's, a Futaba S3114, two HS-5245MG's, and two of my HS-225BB servos survived without a problem.

Asellith · « **Reply #36 on:** March 23, 2008, 12:21:38 PM »

Now all you have to do is develop a sequence timed to the song Kung Fu Fighting

Roberto · « **Reply #37 on:** March 25, 2008, 08:29:55 PM »

Hey ADMIN, just wondering, what wheels are those and where did you get them?

EDIT: Sorry, just read you made them yourself.

Admin · « **Reply #38 on:** March 26, 2008, 08:52:38 PM »

Figured I'd give a quickie update.

The newest version has been fully assembled (see attached image), minus the on off switch that I forgot to make a mount for . . .

Its significantly more stable now that I got that second omni wheel in there. The new claw can finally grab and hold stuff. Still haven't bought a replacement shoulder servo . . .

Currently I am working on getting the blackfin camera functional, and soon after that Ill be trying to get my Axon to communicate with it. I also made a mount for my digital compass, so at some point I'll [finally] integrate that too.

Now I just got to make sure the ninja arms don't karate chop the camera off during testing . . .

tpi008 · « **Reply #39 on:** April 02, 2008, 12:47:43 AM »

Quote from: Admin on March 26, 2008, 08:52:38 PM

Figured I'd give a quickie update.

The newest version has been fully assembled (see attached image), minus the on off switch that I forgot to make a mount for . . .

Its significantly more stable now that I got that second omni wheel in there. The new claw can finally grab and hold stuff. Still haven't bought a replacement shoulder servo . . .

Currently I am working on getting the blackfin camera functional, and soon after that Ill be trying to get my Axon to communicate with it. I also made a mount for my digital compass, so at some point I'll [finally] integrate that too.

Now I just got to make sure the ninja arms don't karate chop the camera off during testing . . .

What is the laser for and what does it do?

I have a crap load of lasers units if anyone is interested in making a deal with me. I have enough lasers for everyone in this forum and maybe more. If anyone is taking on a project similar to this one and need lasers. I can help you out. I'm glad That my stock pile of lasers will have use.

Ro-Bot-X · « **Reply #40 on:** April 02, 2008, 01:03:19 AM »

Are you using PID with your drive servos? How do you accelerate and slow down? I have a hard time figureing this out for my robot and didn't find samples on the net to help me out. I think a pseudocode will help to better understand the ideea than a piece of C code that I can't understand completly (yet...). Think you may be able to help me out here? And others for that matter...

I will start a new topic for this.

Admin · « **Reply #41 on:** April 06, 2008, 04:24:15 PM »

A few quick updates . . .

The arm servo broke AGAIN for a 3rd time!!! Argghhh!! I'm going to have to redesign the shoulder mounts and do new calculations for some other new servo type. I'm tired of buying $30 HS-225MG servos that break . . .

Also, I'm shocked that no one noticed this but . . . 2 castors + 2 wheels will not work! 3 points on a plain work, but not four . . . so I recently designed and completed a neat suspension system for the omni wheels. I'll post pics and a video of the suspension system when I finalize the design.

Quote

What is the laser for and what does it do?

To blind victims! hehe

Actually, you can do neat ranging stuff with a laser combined with a camera.

Quote

Are you using PID with your drive servos? How do you accelerate and slow down? I have a hard time figureing this out for my robot and didn't find samples on the net to help me out.

Are you referring to using encoders with servos?

I'm somewhat religiously against PID . . . I prefer using fuzzy logic for robots. It's simpler, faster, and almost as reliable. You are only kidding yourself if you think deadreckoning works for home based robots . . . With a few exceptions, I'm mostly against encoders, too . . .

Here is a typical fuzzy logic control algorithm:

loop:
{
read sensor values
compute distance needed to travel

//average new value with old motor values
motor_output =
((distance to travel)*(tweak constant) + old_motor_output*3)/4

//store old motor values
old_motor_output = motor_output
}

Not high precision, but really easy and works well under realistic settings. It also does not require the use of encoders!

ps - this is the algorithm I use to control the camera for smooth object tracking

Brandon121233 · « **Reply #42 on:** May 21, 2008, 04:05:38 PM »

Hey Admin did you ever get your robot working since the RoboFest? Or any other new updates?

Admin · « **Reply #43 on:** May 21, 2008, 05:52:48 PM »

It turned out it didn't work because the battery and/or charger wasn't working. I've been trying to get it replaced since, but the company is being 'difficult' . . . I have new updates, but been too busy to post them. It will probably be a month before I find time!

Admin · « **Reply #44 on:** May 24, 2008, 06:28:53 PM »

A new update finally. I basically documented my new suspension system and wrote a tutorial on it:
http://www.societyofrobots.com/mechanics_robot_suspension_system.shtml

Be sure to watch the video!

I also have videos of ERP tracking fire with the camera and other neat things, but I'm pretty busy lately and it'll be awhile before I get those written up.

I need to redesign the arms to handle a new servo . . . the hitec ones keep frying so I'm going to try out Futaba when I have time.

Steve Joblin · « **Reply #45 on:** May 24, 2008, 07:20:58 PM »

Awesome job Admin! Very Very Very Cool!!!!!

There are lots of robot sites, but it is items like this that put this site as one of the best (if not the best!)!

Seems like the next logical step is to set up eCommerce capabilities and start selling those wheels!!

Tsukubadaisei · « **Reply #46 on:** May 24, 2008, 09:50:42 PM »

Quote from: Admin on April 06, 2008, 04:24:15 PM

Quote
Are you using PID with your drive servos? How do you accelerate and slow down? I have a hard time figureing this out for my robot and didn't find samples on the net to help me out.
Are you referring to using encoders with servos?

I'm somewhat religiously against PID . . . I prefer using fuzzy logic for robots. It's simpler, faster, and almost as reliable. You are only kidding yourself if you think deadreckoning works for home based robots . . . With a few exceptions, I'm mostly against encoders, too . . .

I mix both pid and fuzzy. When I am linetracing(just like you do in MOBOT) I use fuzzy. But when I have to use mapping techniques lasers (or cameras) for long periods, encoders(or stepper motors, though I dont like them) are essential. Also that Airship I built uses PID for automatic height control. It is impossible to go for more then 5 meters in a straight line without somesort of speed and position feedback. A curved path is totally out of question. I think fuzzy is better for interacting with external objects. If I were you I would use fuzzy for the manipulator and pid for the wheels. But that is just my opinion.

Parth · « **Reply #47 on:** June 06, 2008, 06:53:09 PM »

Wow, all this stuff is complicated! I can't wait till I get better at robotics and make stuff like this

S. Karim · « **Reply #48 on:** June 08, 2008, 07:41:12 PM »

Wait, how did you get a CMUCam to interface with the Axon?

Admin · « **Reply #49 on:** June 08, 2008, 07:49:50 PM »

Its easy, you just hook up the Rx,Tx, power, and Gnd pins and you're done.

But I never got around to writing the software for it . . .

I just saw your other post asking more about it in my Axon thread . . . I'll answer it in the next few days as I finish up the Axon documentation.

Admin · « **Reply #50 on:** June 15, 2008, 07:14:42 PM »

I haven't had any time to work on ERP in months beyond documenting it. I still need to replace the arm servos with ones that don't break, and also add in an arm motion smoothing algorithm.

For now, enjoy the camera tracking demo.

[youtube]x2od63eroPY[/youtube]

Brandon121233 · « **Reply #51 on:** June 18, 2008, 03:13:54 PM »

whats the light inside the paper ball for?

Admin · « **Reply #52 on:** June 18, 2008, 03:57:47 PM »

Its a blue led, and I programmed ERP to track only blue (not white).

The led has an angle of only like 20 degrees, so the white paper diffused it so the camera could see it better.

Trumpkin · « **Reply #53 on:** June 18, 2008, 08:04:31 PM »

very nice. whats up with the pikachu?

heartpooh · « **Reply #54 on:** July 07, 2008, 09:46:56 PM »

hi admin, i wonder if u could explain to me the properties of using the omni wheels?

Admin · « **Reply #55 on:** July 08, 2008, 05:02:49 AM »

Quote

i wonder if u could explain to me the properties of using the omni wheels?

For this robot I'm just using them as caster wheels.

check this out:
http://www.societyofrobots.com/robot_omni_wheel.shtml

No new ERP updates at the moment . . . been too busy with the Axon:
http://www.societyofrobots.com/axon
(the same mcu that I use on ERP is now available for sale)

Cotowar · « **Reply #56 on:** July 10, 2008, 09:49:27 PM »

Someone asked about a CNC machine. CNC machines come in all shapes and sizes, from the one in my garage on the bench, to the one at my dad's work with 10-axis milling. It's all in what you want to do, and how much you are willing to pay.

Just go to home depot, lowes, or menards and ask about it. I'm sure they can hook you up.

if not, try these
http://www.cncmasters.com/CNC%20Supra%20Retrofit%20Kit.htm
http://www.minitechcnc.com/

Admin · « **Reply #57 on:** July 13, 2008, 11:46:05 AM »

[admin spam]

The contest ends in ~3 days, help me win!

vote here by clicking 'vote' at the top right-ish area of the page:
http://www.instructables.com/id/Experimental-Robot-Platform/

[/admin spam]

garriwilson · « **Reply #58 on:** July 13, 2008, 03:02:33 PM »

Quote from: Admin on July 13, 2008, 11:46:05 AM

[admin spam]

The contest ends in ~3 days, help me win!

vote here by clicking 'vote' at the top right-ish area of the page:
http://www.instructables.com/id/Experimental-Robot-Platform/

[/admin spam]

*gasp* admin spammed *gasp*
lol i voted like a week ago

Admin · « **Reply #59 on:** August 13, 2008, 01:41:04 PM »

ERP won the instructables contest! yaaaaaay!

(and thanks for the votes everyone!)

http://www.instructables.com/community/RoboGames_Robot_Contest_Winners/

Quote

The author of this Instructables will receive a trip to the June 2009 RoboGames in San Francisco, CA! Includes airfare for one from anywhere within the continental US, 4 nights in a hotel near the event, and VIP access/entry fees.

I'll make sure to take lotsa vids and pics to share for everyone. I guess ERP is now entering another contest, just got to finish all the upgrades . . .

News:

Author Topic: CAD of my newest robot (Read 69713 times)