Note to Microsoft (for their RDS page): It's not "differential drive." It's differential steering. Cars use differential drive -- assuming they have a differential. Robots (and bulldozers and tanks and...) use differential steering. Whole world of difference in these two differentials.
-- Gordon
Gordon, I really,really hate to disagree with you and agree with MS, but "differential drive" is universally used in robotics to convey that kind of robot (two wheels driven independently, additional wheels to provide support but not affect direction). Differential steering maybe the correct grammar (not really sure about that) but differential drive is the term used most frequently and its meaning in this context is right on.
It uses the same platform as the MadeUSA. I really do not think that it can take the weight of even a partially grown human.
At UPEW 2 years ago, I watched Ken ride around on top of the prototype plywood version of the MadeUSA. The Black platform version is at least as strong. The motors have no problem with the weight.
What I want to know is will I be able to buy the parts to upgrade my MadeUSA to one of these?
Even if I need a new base disc, I already have the motors, casters, and pings.
At UPEW 2 years ago, I watched Ken ride around on top of the prototype plywood version of the MadeUSA. The Black platform version is at least as strong. The motors have no problem with the weight.
I stand by my assertion that Eddie cannot carry around a human. You can prove me wrong with a video.
Gordon, I really,really hate to disagree with you and agree with MS, but "differential drive" is universally used in robotics to convey that kind of robot (two wheels driven independently, additional wheels to provide support but not affect direction). Differential steering maybe the correct grammar (not really sure about that) but differential drive is the term used most frequently and its meaning in this context is right on.
"Differential drive" has never been correct, though over the years more and more people have misapplied the term. To defend the inaccurate use though would be like saying "imformation" is the correct word simply because some people actually think this is a real word!
Here's why differential drive it's not correct: what's of concern is the control of the platform/vehicle, and for something like a robot, that's always through its steering. All of the descriptors for various robotic control methods refer to its steering.
The "drive" is something separate, and lives its own life apart from the steering mechanism. This is from mechanical necessity. It can be direct drive, indirect drive, gear drive, hydraulic pump, and dozens of other things. Because one form of drive can be combined with any number of steering methods, the two are kept separate.
This isn't just my rule (I'm not really into rules) but an observation of decades-old terminology. A robot doesn't steer any differently than a tank or any other vehicle with the same wheel or tread arrangement. I think you'll find that the *textbook* term (at least the authoritative textbooks) have long used differential steering, even if some robot builders might have later misapplied the term.
I pointed to the relevant wikipedia page, which states it correctly. Their page for "differential drive" properly references a drive mechanism through a differential gear.
Your post sort of proves I'm probably battling a losing war, but what's at risk is loss of precision. When you think about it, "differential drive" is a meaningless term, because it could apply to any of several things -- drive, steering, what?
I stand by my assertion that Eddie cannot carry around a human. You can prove me wrong with a video.
Ahh, Rich, you're going to make us work! Here's the deal. My kids (same size as your kids) regularly sit on my Madeusa robots and drive them around the house using XBee. I've ridden one and so has Kevin. It's certainly not suggested to carry a 200-pounder and I'm sure the current draw is really high, but the motor mount and wheel kit will do the job. Again, totally impractical but entirely possible.
@Roy, we'll set you up as soon as possible. The control electronics are being manufactured this week. What I'm most excited about is that we've got a committed partner who sees value in what we offer with this robot and they're purchasing them for a contest. I realize that few of you will put PCs on robots, but Microsoft has a whole crowd of customers who will. There's a Propeller in the control system, too.
It uses the same platform as the MadeUSA. I really do not think that it can take the weight of even a partially grown human.
Like Roy sez, it can handle a full grown man pretty well. Ken is taller than the average guy, at that. It has a mean acceleration curve, though, so wear a crash helmet.
I saw "This Island Earth" on TV 56's Creature Double Feature sometime during the late 70's or early 80's. This guy
scared the pants off me.
The movie that most scared me was "The Thing From Another Planet" with James Arness as the "space monster". It was months before I could sleep through the night!!!!!!!
Okay, you win. Sort of. I will concede that the MadeUSA is capable of supporting the weight of a human and that it can move around with said human atop - so long as considerable care is taken. However I still say that Eddie cannot carry a human AND operate normally. I'll need a video to concede that one.
So where am I supposed to put my feet on the MadeUSA? I want to take it for a spin!
@Roy, we'll set you up as soon as possible. The control electronics are being manufactured this week. What I'm most excited about is that we've got a committed partner who sees value in what we offer with this robot and they're purchasing them for a contest. I realize that few of you will put PCs on robots, but Microsoft has a whole crowd of customers who will. There's a Propeller in the control system, too.
Ken Gracey
Ken,
Looking at the platform today at Maker Faire, I could not see a Propeller on a board made by Parallax. All I saw was a 4-port USB board. Was it buried where I couldn't see it?
@Roy, we'll set you up as soon as possible. Ken Gracey
@Ken: Hey, I don't believe it either. Neither do my wife or twins. So whatever you do, don't send us 4 units and prove us all wrong!
Eddie looks very cool. Not what I was expecting, but very cool nonetheless. A nice expandable platform, reminds me a bit of Evolution's ER-1. Just don't follow their (and Whitebox's) model of overpromising and leaving people hanging. If you just put it out there and wait for someone else to come up with the "killer app", you're dead. Whitebox copped out with their line "the only limit is YOUR imagination". Lead the way in well-thought-out accessories and applications; hopefully you'll have an arm and gripper in short order.
Nice job! This should re-energize interest in Microsoft Robotics at the hobby/consumer level. And if you're smart (and you are), you'll get this thing into some university programs. At $999 or less, it's the cheapest platform around.
I've been saving my money to invest in a good robot base (as in, for the bottom of a larger bot )for a long time now.... I'm not too far away from affording the Medusa base, but now this product arises and makes me wonder if I should wait JUST a little longer to get it? What are the advantages to this besides the fact that it runs Microsoft's robot software?
The photo provided shows handle holes cut into the upper deck, directly above the wheels. Clearly handles are appropriate on a bot of this size, but removing material there eliminates real estate above the wheels for side-looking sensors, laptop mounts, etc. As an alternative, how about leaving it solid and using everyone's favorite metal U-handles instead?
@Microcontrolled, apparently the keyboards made for dogs or cats are missing letters and spell checking. At least that's how it appears on http://icanhascheezburger.com/.
Mine has handles front and back on the bottom deck. I recommend them. The second deck of Eddie is more or less a dupe of the first deck. I guess it would be okay to use the cutouts as handles if the hardware is sure to hold. I'm using 5/16 carriage bolts. Having handles in the bottom allows the bot to be carried when there's no second deck and laptop.
I put the deck for the laptop higher so I could place "sub decks" below. This provides more real estate. Under the blue deck goes an amplifier and speaker, plus a Parallax LiPoly battery pack and charger. On the deck is the controller, any expandable circuit board area I need, plus an LCD and keypad for direct control.
The sub-deck also allows easy change of controllers. I've used the Madeusa with both a Propeller and an Arduino.
The Madeusa has a very low center of gravity, because the 7A 12V battery is slung underneath. The laptop deck can be raised several inches without risk of anything tipping over.
In another thread (#64) I reported on an impromptu load test of 40 lbs. or so, and then pushed it to the limit by giving Scott (our machinest) a ride on one of the new HDPE Robot Base Kits. @ a full 12 volts of power to both motors, he rode for about 12 feet and then lost his balance, fell forward and ended up breaking a caster bracket. Scott weighs 195 lbs. Both the Caster and Scott were repaired in relatively short order.
Do we specify this as a load capacity? Of course not. However, there is a lot of power there, and only you and the terrain that you're running it on can decide what the upper limit is
The only *edit* I would add to my quote is to change "there is a lot of power there..." to "there is a lot of capacity there".
As Ken said, it's not really practical to carry a load this large, but we have done it. We'll put together a short video soon.
The handle cut-outs on the 2nd deck are considerably smaller than the ones on the lower deck (the ones for the motors).
By incorporating the handles into the platform (as opposed to "standoff handles" (like Stingray), you don't really lose any real-estate. If you wish to span across the handle-hole with a circuit board (or a large laptop), you can. Handles would need to be removed otherwise.
Plus, the weight of the overall assembly is considerable: Eddie can carry two 7.5 ah, 12v SLA batteries. Incorporating handles into the structure design itself means they won't (can't) bend, tweak, or "pull out".
A fellow forum member emailed this picture to me, it's from the latest MS RDS beta.
Good design; I have some suggestions!
If the upper deck can be rotated 90 degrees (the column mounting holes are symmetrically square), then you can position the cutout handles front and back, leaving a nice area for mounting a Ping on either side. With that arrangement Eddie can navigate halls. (It's even better if there can be two Pings per side, and that way the robot doesn't have to first move to determine its attitude in reference to the wall.)
I think I would have created a combined IR+ultrasonic mount for the center. Maybe that could be offered as an option (to my knowledge Parallax doesn't yet sell a combination IR and Ping mount, but that's easily rectified). That would provide the benefits of some fusion for the most critical direction to the robot, which is straight ahead.
I might have extended the length of the deck columns a bit more, at least as it appears in the rendering and the photos. I like to put things on the underside of upper decks. It doubles the mounting space, and works well for anything that won't fall out -- good for speakers, amplifiers, many kinds of sensors; not good for most kinds of battery holders, or solderless breadboards. As I noted elsewhere, the battery slung under the bottom base provides a very low center of gravity for the Madeusa, so the second deck can be higher up, without any risk of instability.
Anyway, my two cents, which I think in today's economy is worth about 0.78 cents.
The Microsoft Kinect is ment to be the main sensor. Not the PING))) or IR sensors. Those are just to give the Kinect enough information to avoid any obstacles the Kinect cannot see.
The Microsoft Kinect is ment to be the main sensor. Not the PING))) or IR sensors. Those are just to give the Kinect enough information to avoid any obstacles the Kinect cannot see.
I probably would have done it differently (used the Kinect more for gesture detection, mapping, that sort of thing), and added a few more sensors at the bottom base that were operated in real time by the Propeller.
But this is what the Madeusa/Eddie platform was designed for -- an open and easily adaptable robot to let people decide the way they want to do things.
Comments
It uses the same platform as the MadeUSA. I really do not think that it can take the weight of even a partially grown human.
Gordon, I really,really hate to disagree with you and agree with MS, but "differential drive" is universally used in robotics to convey that kind of robot (two wheels driven independently, additional wheels to provide support but not affect direction). Differential steering maybe the correct grammar (not really sure about that) but differential drive is the term used most frequently and its meaning in this context is right on.
At UPEW 2 years ago, I watched Ken ride around on top of the prototype plywood version of the MadeUSA. The Black platform version is at least as strong. The motors have no problem with the weight.
Even if I need a new base disc, I already have the motors, casters, and pings.
I stand by my assertion that Eddie cannot carry around a human. You can prove me wrong with a video.
"Differential drive" has never been correct, though over the years more and more people have misapplied the term. To defend the inaccurate use though would be like saying "imformation" is the correct word simply because some people actually think this is a real word!
Here's why differential drive it's not correct: what's of concern is the control of the platform/vehicle, and for something like a robot, that's always through its steering. All of the descriptors for various robotic control methods refer to its steering.
The "drive" is something separate, and lives its own life apart from the steering mechanism. This is from mechanical necessity. It can be direct drive, indirect drive, gear drive, hydraulic pump, and dozens of other things. Because one form of drive can be combined with any number of steering methods, the two are kept separate.
This isn't just my rule (I'm not really into rules) but an observation of decades-old terminology. A robot doesn't steer any differently than a tank or any other vehicle with the same wheel or tread arrangement. I think you'll find that the *textbook* term (at least the authoritative textbooks) have long used differential steering, even if some robot builders might have later misapplied the term.
I pointed to the relevant wikipedia page, which states it correctly. Their page for "differential drive" properly references a drive mechanism through a differential gear.
Your post sort of proves I'm probably battling a losing war, but what's at risk is loss of precision. When you think about it, "differential drive" is a meaningless term, because it could apply to any of several things -- drive, steering, what?
-- Gordon
Ahh, Rich, you're going to make us work! Here's the deal. My kids (same size as your kids) regularly sit on my Madeusa robots and drive them around the house using XBee. I've ridden one and so has Kevin. It's certainly not suggested to carry a 200-pounder and I'm sure the current draw is really high, but the motor mount and wheel kit will do the job. Again, totally impractical but entirely possible.
@Roy, we'll set you up as soon as possible. The control electronics are being manufactured this week. What I'm most excited about is that we've got a committed partner who sees value in what we offer with this robot and they're purchasing them for a contest. I realize that few of you will put PCs on robots, but Microsoft has a whole crowd of customers who will. There's a Propeller in the control system, too.
Ken Gracey
Like Roy sez, it can handle a full grown man pretty well. Ken is taller than the average guy, at that. It has a mean acceleration curve, though, so wear a crash helmet.
-- Gordon
The movie that most scared me was "The Thing From Another Planet" with James Arness as the "space monster". It was months before I could sleep through the night!!!!!!!
Amanda
So where am I supposed to put my feet on the MadeUSA? I want to take it for a spin!
Ken,
Looking at the platform today at Maker Faire, I could not see a Propeller on a board made by Parallax. All I saw was a 4-port USB board. Was it buried where I couldn't see it?
Jim
@Ken: Hey, I don't believe it either. Neither do my wife or twins. So whatever you do, don't send us 4 units and prove us all wrong!
Eddie looks very cool. Not what I was expecting, but very cool nonetheless. A nice expandable platform, reminds me a bit of Evolution's ER-1. Just don't follow their (and Whitebox's) model of overpromising and leaving people hanging. If you just put it out there and wait for someone else to come up with the "killer app", you're dead. Whitebox copped out with their line "the only limit is YOUR imagination". Lead the way in well-thought-out accessories and applications; hopefully you'll have an arm and gripper in short order.
Nice job! This should re-energize interest in Microsoft Robotics at the hobby/consumer level. And if you're smart (and you are), you'll get this thing into some university programs. At $999 or less, it's the cheapest platform around.
I put the deck for the laptop higher so I could place "sub decks" below. This provides more real estate. Under the blue deck goes an amplifier and speaker, plus a Parallax LiPoly battery pack and charger. On the deck is the controller, any expandable circuit board area I need, plus an LCD and keypad for direct control.
The sub-deck also allows easy change of controllers. I've used the Madeusa with both a Propeller and an Arduino.
The Madeusa has a very low center of gravity, because the 7A 12V battery is slung underneath. The laptop deck can be raised several inches without risk of anything tipping over.
And yes, Erco, the laptop deck is HDPE.
FEET?
The correct way of riding a Madeusa:
"
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Index was outside the bounds of the array.
"
This one of my posts from another thread:
The only *edit* I would add to my quote is to change "there is a lot of power there..." to "there is a lot of capacity there".
As Ken said, it's not really practical to carry a load this large, but we have done it. We'll put together a short video soon.
-Matt
The handle cut-outs on the 2nd deck are considerably smaller than the ones on the lower deck (the ones for the motors).
By incorporating the handles into the platform (as opposed to "standoff handles" (like Stingray), you don't really lose any real-estate. If you wish to span across the handle-hole with a circuit board (or a large laptop), you can. Handles would need to be removed otherwise.
Plus, the weight of the overall assembly is considerable: Eddie can carry two 7.5 ah, 12v SLA batteries. Incorporating handles into the structure design itself means they won't (can't) bend, tweak, or "pull out".
-Matt
I can see the picture clearly, but I got that Exact error when searching for 'BS2' on Parallax's website!
Good design; I have some suggestions!
If the upper deck can be rotated 90 degrees (the column mounting holes are symmetrically square), then you can position the cutout handles front and back, leaving a nice area for mounting a Ping on either side. With that arrangement Eddie can navigate halls. (It's even better if there can be two Pings per side, and that way the robot doesn't have to first move to determine its attitude in reference to the wall.)
I think I would have created a combined IR+ultrasonic mount for the center. Maybe that could be offered as an option (to my knowledge Parallax doesn't yet sell a combination IR and Ping mount, but that's easily rectified). That would provide the benefits of some fusion for the most critical direction to the robot, which is straight ahead.
I might have extended the length of the deck columns a bit more, at least as it appears in the rendering and the photos. I like to put things on the underside of upper decks. It doubles the mounting space, and works well for anything that won't fall out -- good for speakers, amplifiers, many kinds of sensors; not good for most kinds of battery holders, or solderless breadboards. As I noted elsewhere, the battery slung under the bottom base provides a very low center of gravity for the Madeusa, so the second deck can be higher up, without any risk of instability.
Anyway, my two cents, which I think in today's economy is worth about 0.78 cents.
-- Gordon
I probably would have done it differently (used the Kinect more for gesture detection, mapping, that sort of thing), and added a few more sensors at the bottom base that were operated in real time by the Propeller.
But this is what the Madeusa/Eddie platform was designed for -- an open and easily adaptable robot to let people decide the way they want to do things.
-- Gordon