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bobasan
11-25-2008, 11:23 AM
Hi all,

I am in the process of trying to move away from my now deceased ER1 and I am looking for a little guidance. I have linked a system diagram and a pic of the ER1 in its final iteration without any of the attachments or peripherals. It stands at just under 36" tall as shown and weighs in at 30lbs with its 33AH 12VDC AGM battery. Not shown is its self charging station, second camera, IR sensors, gripper arm and lighting package. All that said, here is what I was using it for was:

Two way remote presence (virtual party guest)
Security check of the house while we were away
Mobile interface to our home automation and media
Playing a character in a host a murder mystery game (hence the hat and goggles)

Capabilities I would like to add:
Arm to hold/grab and move items up to 2lbs
Faster movement
Pan and tilt of main camera

I've also linked a rough system diagram of what I am thinking I need to put together electromechanically for the new configuration. So here are my questions:

1. Am I missing anything systemically in the new configuration?
2. What should I be getting on the power curve for in regards to coding? (C, C+, C++, etc.)
3. In looking at the arm are there any examples I can look at in vision controlled autonomous arms?

Also, to give a bit of background I am coming at this from the hardware side more than programming. My programming skills are waaaaaay out of date. Think assembler-Fortran-Cobol from the late 80's. On the hardware side, mechanically I can machine/fabricate anything on my own and electrically I can read a schematic and assemble most things. Anyway, I look forward to everyone's suggestions.

Bob


ER1 pic http://www.monkeyfunhouse.com/images/er1.jpg
ER1 system diagram http://www.monkeyfunhouse.com/images/er1sysdiag.jpg
New system diagram http://www.monkeyfunhouse.com/images/newsysdiag.jpg

darkback2
11-25-2008, 11:56 AM
I went through the same crisis a few years ago, and started completely from scratch.

For vision, check out roborealm (http://www.roborealm.com/tutorials.php)

For drive motors check out the parallax motors (http://www.trossenrobotics.com/store/p/5761-Motor-Mount-Wheel-Kit-with-Position-Controller.aspx)

For control...phidgets (http://www.trossenrobotics.com/p/phidget-advanced-usb-servo-controller.aspx) or an SSC-32 (http://www.trossenrobotics.com/store/p/3191-SSC-32-Servo-Controller.aspx)

You already have 80/20 frame material and all the brackets you could shake a stick at.

For the pan/tilt camera (http://www.trossenrobotics.com/store/p/3139-Pan-and-Tilt-Kit-with-Servos.aspx)/arm...check out the SES system from lynxmotion (http://www.trossenrobotics.com/store/c/2706-Joint-Brackets.aspx)

Finally check out my thread on gepetto and vivian (http://forums.trossenrobotics.com/showthread.php?t=1439).

As for programming...I use a program called Max/MSP. Check out microsoft robotics studio...

I dunno...hope this helps.

DB

Adrenalynn
11-25-2008, 12:08 PM
On the servo controller - I'd wait just a little bit if I could, then pick up a Serializer and the new ServoWizard.

elios
11-25-2008, 01:02 PM
ill get 4mem8 to have a look at this thread. he has an ER1 that he loves, and he is trying to get the scorpion.

bobasan
11-25-2008, 02:34 PM
Darkback2,
Thanks for all the suggestions. I've been playing with roborealm and it seems pretty straight forward. As for the parallax motors I like them but I would rather machine my own mounts than go with what they come with. I actually have a decent mill and lathe at the house. As for the rest I'll read through all I can.

Adrenalynn,
The serializer looks great but I am unfamiliar with "ServoWizard" also why is there a need to wait?

Elios,
I'd love to see what someone else has done with their er1. That said, I am thinking darkback is right about never getting a proprietery system again.

Well everyone, with all that said was there anything systemically that any of you thought I might have missed? I'll be filling in specific components as I go. I hope to have everything detailed out in time for me to order everything by the holiday break. Thanks everybody for the great forum and input.

Bob

Adrenalynn
11-25-2008, 03:00 PM
The ServoWizard isn't (afaik) released quite yet. Reliable sources have it "almost there"...

darkback2
11-25-2008, 03:01 PM
Sorry...the parallax system was a suggestion for two reasons. To be honest I just bought the denso motors the parallax kit is based on seperately and machined mounts at the local skills center. For former ER-1 users I find having some way to count wheel rotations to be helpful...given that it is how the ER-1 determines or tried at least to know where it is. Oddly, the Denso motors have gotten way hard to find anymore. Good thing I got 40 of them a few years ago. ( I teach a robotics class.)

Also, I know adrenalynn isn't a fan of the Phidget 8/8/8, but its a dead easy way to get sensor data into your robot. They also have a 0/16/16 which should be as good with twice the number of inputs.

Hope this helps.

DB

Adrenalynn
11-25-2008, 03:03 PM
The Phidgets 8/8/8 is *incredibly* slow, and even if it wasn't, it's over-priced by twice.

bobasan
11-25-2008, 03:07 PM
Thanks for the responses. As for control I like the thought of have the controller do as much as possible with the computer getting spit back just the relevant data so I think the serializer is probably a better fit in that regard. That said those phidget components look to be pretty damn easy to implement. Looking at all this I am having weird flashbacks to my HERO1 he he.

Bob

Adrenalynn
11-25-2008, 03:30 PM
The Serializer is dirt-simple. If you want .Net they have a *very* well supported .Net library. But you can talk to it from anything with any language that can open some kind of serial connection or pipe. In that, it's compatible with any operating system in existance today. Windows? Duh. Mac? Sure. Linux? Go ahead. Wanna run CE? Be my guest. Some RTOS? Why not?

The Serializer also supports a tremendous range of communications options that you don't get with Phidgets. Phidgets are USB. You need a USB host controller to plug 'em in to. With the Serializer you can do Bluetooth, Zigbee, RS232, USB and TTL serial before you even have to get creative. I've had it running on both wired ethernet and wifi too (with a third-party TTL to Ethernet adapter). You'd be hard pressed to make that work with Phidgets.

Phidgets are great [ok, in the case of their capture devices, "mediocre" is closer. Too slow to be even "good"] for building desktop toys. I see them as limiting your processing choices on the robot-side, though.

As DB has said - he and I agree to disagree on their value. ;)

It's unquestionable, though, that the Serializer has more feature-set for the same money. Show me the single Phidgets device that will control a handful of servos, talk to a handful of sensors, deal with the output of a couple Quadrature encoders, read and write I2C, AND control a couple small motors without external devices (or drive larger motors with additional hbridges). With the addition to the line of the RangeWizard (for better more complete range-finder support) and the ServoWizard (25 servo support), driven off the I2C of the Serializer and communicating over whatever the Serializer is using, well - now you have a total solution regardless of where the processing power is actually living.

On the higher-end Zigbee devices, you could directly wirelessly be talking to and from the robot from 20 or more MILES away. Hard to find a 20mi long USB cable... ;)

darkback2
11-25-2008, 03:52 PM
OK Adren,

I don't agree to disagree...I just know how to use phidgets, and don't have, have never tried working with a serializer. Could probably do it...just haven't gotten one or around to it. That said, with your help I quit using the phidget 4s and started using the SSC-32...

See...I can learn.

DB

bobasan
12-04-2008, 11:35 AM
Well I am slowly pulling things together. Right now though I am working on a design for an arm. One question though, I don't see any designs using an isoelastic configuration similar to a steadicam's arm. I was wondering if anyone could point me in the direction of any examples. Attached is picture my diy stedicam arm that I am thinking of loosely basing my robot's arm on.

Bob

ScuD
12-04-2008, 02:48 PM
Did you mill that thing yourself?

Looks awesome.. I'm a sucker for blank metal :veryhappy:

Not a lot of isoelastics going on here, though Tybs has used RC shocks on his J5 bot to compensate for weight issues, which I guess is a form of isoelastics?

I've played with the idea before (and actually, the first bot I built used it without me actually knowing what it was) but it's proven hard to integrate in my designs so far.

Seeing what you've built above here, I can't wait to see what you come up with!

bobasan
12-04-2008, 06:40 PM
Scud,

Yeah, I ended up machining the whole thing. I tried to find some appropriate extrusions but none were available at the time so I ended up milling everything from solid blocks. As to what I am trying to sort out for the robot it won't need to be nearly so massive since I am looking at a working load of no more than 3lbs. The steadicam arm shown, depending on the springs I use, can fly up to 58lbs but it also weighs a whole heluva lot ;) As soon as I get some decent drawings together I'll post them up.

Bob

Adrenalynn
12-04-2008, 07:56 PM
At 58lbs, I assume it has counter-weighting too? (I fly a "Clipper" [certified], and with a 22lb DVCHD it needs about 7lbs of batteries extended all most all the way out before it really settles down)

Most of the commercially available arms I've seen use springs to counter and soften the robotic arms. My SG6 Crustcrawler and the SES Lynxmotion come to mind. The Crustcrawler uses springs from the lower arm to the elbow and from the elbow to mid upper-arm.

bobasan
12-04-2008, 09:13 PM
Adrenalynn,

When I first built the rig I was flying a Varicam on the rig. The sled, camera, lens, remote follow focus, monitor, batteries, etc would run up to 43lbs. Now I generally fly around 26lbs with an HVX200 with a RedRock M2 35mm adapter, remote follow focus, etc.

In regards to the robot arm, thanks so much for information. I'll take a look at the units you listed. I am hoping to put something together that can use minimally powered servos/motors and has a good degree of operational stability. I think I can put something together to fit the bill.

Bob