pic: 2003 TechnoKat Ball Drive : Patent Pending [Archive]

Andy Baker

03-03-2003, 13:44

OK, here is the scoop:

Mark Koors, TechnoKat - Delphi engineer, thought of the idea. We worked together in the fall to come up with a design for this. The team made a prototype during the late fall and had a rough proto working by the time of kickoff (it had bigger balls and only casters to keep it balanced).

Then, kickoff came and we had to decide what to build as a team: a strong track drive that can push really hard, or a quick and agile ball drive that had very limited pushing abilities.

We had a big disagreement. The team was split between the two drive bases, and we could not just pick one.

What we did decide was to make the track drive base our primary design that 95% of the team would focus on. The students and engineers worked together on the track drive base, making gearboxes, pulleys, spare parts, etc. At the same time, one engineer (Mark) worked on the ball drive base with some help from students and other engineers only if there was nothing to do on the track drive.

In the end, the ball drive robot was wired and programmed by the students, only after they got done with the track drive robot.

This was not easy to do... and we may not even get to use the ball drive robot. Unfortuneately (for many reasons) the two drive bases are not modular. Our original plan was to have a "control box" that could be switched between the two bases (similar to 190's control box in 2001). But, that did not work too well due to size, time, weight and money constraints.

So, we can switch between the two robots... but it would take alot of time. I am estimating about 2-4 hours of work to switch over the gearboxes (and re-allocate the CIM motor to another gearbox), move over the electronics (controller, fuse panels, RF transmitter, and victors), and the light. It could be done if we had to do it. Also... both robots come in at $3,473, including the polycarbonate arm on the Mighty Mouse.

So... if our Mighty Auk sucks so bad that it would not do well in the finals, we may offer our Mighty Mouse as a partner to a team who needs a highly-mobile, limboing stack wrecker.

We are not sure if this second robot was the right thing to do. We did not make a practice robot because of this 'bot... but I feel that the inspiration behind this robot is worth it. Time will tell.

Thanks goes out to all of the TechnoKats and a few others who knew about this design and kept quiet. Our management here at Delphi has recommended that we go ahead and file for a US patent on this design (which we did) so that our rights are protected.

This thing is a ball to drive. Please stop by our pit to check it out.

Andy B.

Andy Baker

03-03-2003, 13:50

Originally posted by Jnadke
Are the balls air-filled or solid rubber? If they are air-filled, how thick is the skin?

I'd imagine the drivetrain is optimized with speed in mind rather than torque. How much torque can you exert on the surface of the ball before it slips?

The balls are 8" steel "gazing balls" (hollow) that you can buy from a home deco store (we got them for $6 per ball at Homier.com). These balls have urethane molded over them at about a 1/4" thickness. They are about +/- 0.003" out of round. They dent if dropped, and weigh about 3-4 lbs each. They are not inflatable.

This drivetrain is optimized for mobility. The speed and power is less than an optimized track drive robot... but this thing can go from travelling straight to turning right of left with absolutely no delay.

As for how much torque this can put out or how much torque a ball can handle... we don't know yet.

Andy B.

Joe Matt

03-03-2003, 14:00

While I think this is great and very cool, I just wonder if this years task was so simple that we can afford such lavash things. What about other teams who can barely move? Were the TechnoCats right to spluge on their drive while many teams still don't move?

Just a question.

abeD

03-03-2003, 14:07

How exactly does it work, do the wheels just spin clockwise or counter clockwise and if they are above the ground?? I don't exactly get it and it would be cool to get an explanation

thanks

WernerNYK

03-03-2003, 14:09

I dont really see the great advantage of something like this.... Obviously extreme mobility, but not so much more than can be accomplished with other drive systems, or that such mobility would really be necessary, or even that easily controlled.

I'd like to actually see this thing and evaluate it further.

Madison

03-03-2003, 14:09

Originally posted by JosephM
While I think this is great and very cool, I just wonder if this years task was so simple that we can afford such lavash things. What about other teams who can barely move? Were the TechnoCats right to spluge on their drive while many teams still don't move?

Just a question.

It's a really dumb question.

The TechnoKats have the resources to do things like this, so there's absolutely nothing wrong with it. If a team with lesser resources wanted to try something similar, there's nobody stopping them.

FIRST is about making intelligent decisions regarding your strategy while keeping in mind your opponents, your philosophy, and your resources.

What did you want the TechnoKats to do, exactly? Were they supposed to build another robot that they would donate to a team?

David Kelly

03-03-2003, 14:13

Originally posted by JosephM
While I think this is great and very cool, I just wonder if this years task was so simple that we can afford such lavash things. What about other teams who can barely move? Were the TechnoCats right to spluge on their drive while many teams still don't move?

Just a question.

what does that have to do with anything?? if they have money, and energy and resources to make 2 robots, all the power to them....

its sad to see people criticize other teams for doing something good.

Now i dont have to keep my mouth shut anymore, T-Kats. ;) This is an awesome drive system and it's great that you are using your resources to move it to the next level for everyone. I've seen some video of this in action, and i'd have to say that it is amazing. Nice job guys, cant wait to compete you in Chicago :cool:

Joe Matt

03-03-2003, 14:17

I never criticized the Tcats at all. I said I like it. I'm just saying that mabey the effort to build another bot or another drive system could have gone to inspiring another team.

Andy Baker

03-03-2003, 14:17

Originally posted by JosephM
Were the TechnoCats right to spluge on their drive while many teams still don't move?

Just a question.

Hopefully, this thing may inspire some people. FIRST is about inspiration.

Also, as for the cost... the parts on this cost about $700. I don't see it as a splurge.

Andy B.

Chris

03-03-2003, 14:18

Wow.......Just wow.....I'm amazed by this and the other techno Kat robot. I say congratulations....Not only for having two awesome robots, but for being brave enough to try. And to WernerNYK who cares if its an advantage, its just cool that they did it. I mean its a totally revolutionary drive train, its great that it just exists, even if its not an advantage( which I personally think it is).

Chris

Good job, don't listen to negative people

David Kelly

03-03-2003, 14:23

Originally posted by JosephM
I never criticized the Tcats at all. I said I like it. I'm just saying that mabey the effort to build another bot or another drive system could have gone to inspiring another team.

what they did, is inspiring other teams. it can give others new ideas for future competitions.

explain what you meant by "mabey the effort to build another bot or another drive system could have gone to inspiring another team."

that makes no since to me...

Madison

03-03-2003, 14:26

Originally posted by WernerNYK
I dont really see the great advantage of something like this.... Obviously extreme mobility, but not so much more than can be accomplished with other drive systems, or that such mobility would really be necessary, or even that easily controlled.

I'd like to actually see this thing and evaluate it further.

The advantage is that it's far less technically complex than any swerve drive.

After all, swerve drives are designed to emulate the sort of movement this can provide, doing so by mimicking the single plane that intersects the sphere's surface that is riding along the floor.

It's no different than a swerve drive, really, but it is simpler. At least, as far as I can tell. . . the major disadvantage is that it's driven by two relatively smooth surfaces interacting with one another, and that means "stalling" is a possibility.

SuperJake

03-03-2003, 14:41

What can I say other than 'Wow'? I mean it is really cool! I'm deffinetly gonna make some time to stop by your pits in Houston! Good luck!

Joe Matt

03-03-2003, 14:57

?7?i]Originally posted by David Kelly [/i]
what they did, is inspiring other teams. it can give others new ideas for future competitions.

explain what you meant by "maybe the effort to build another bot or another drive system could have gone to inspiring another team."

that makes no since to me... [/QUOTE]

Why not take some of the money that would have gone to building another bot or a more complicated drive system and give it to a struggling team or a new team?

ZACH P.

03-03-2003, 15:09

Originally posted by David Kelly
I've seen some video of this in action, and i'd have to say that it is amazing.

i'd like to see that video, does anyone have it?

oh, awesome 'bot, but i'm worried about the power transfer to the actual suface of the balls, how do you acomplish the need friction while still allowing it to move in other directions? And how is the traction on the HDPE?

Awesome, i never thought anyone would actually implement a ball drive.

Thanx

WernerNYK

03-03-2003, 15:12

I wasnt really being negative at all. New ideas and concepts are always great. I'm just a bit skeptical as to what kind of difference this will actually make compared to other traditional drives, which is why I said that I would like to see it in person in closer detail... possibly try moving it around.

I mean, look at team 190... we're always coming up with brand new ideas (translational drive, "wonder wheels," CVTs, INS, amongst other things). I'll never knock an good idea, new engineering concepts... I think it's great. Believe it or not, I know I personally was thinking of a similar type of systems earlier this year, and I know a few of my teamates were as well.

And I think someone else mentioned that it could "stall"... this is entirely true... a more descriptive term would be slipping. When a system lies entirely upon friction, slippage will -- at some point -- occur... even our CVT system will slip under certain circumstances.

Madison

03-03-2003, 16:02

Originally posted by WernerNYK
And I think someone else mentioned that it could "stall"... this is entirely true... a more descriptive term would be slipping. When a system lies entirely upon friction, slippage will -- at some point -- occur... even our CVT system will slip under certain circumstances.

"Slipping" occurs in all drive trains, really, whether it occur where the wheels interface with the carpet, or where the chain meets a sprocket. Gears, well, can't slip.

I used "stall" because it seems to me that, unless the point at which the omniwheels and the balls slip is the same, the drivetrain might do funny things. Of course, it seems likely that the balls would slip somewhere before the omniwheels slipped along the carpet, and at that point, they'd be acting as casters. It's getting to that point that seems like it'd be the biggest problem to me. That is, if the ball is slipping some and isn't driving at the same speed as the omniwheel, the drivetrain would become inefficient and could, possibly, bind.

I'm interested in seeing how the Technokats overcame that issue, or if it was really an issue at all.

Joe Matt

03-03-2003, 16:14

But the ball system is more suseptable to slipping compared to the traditional motors/gears/wheels system.

Gope

03-03-2003, 16:17

WHAT?!?!?! :eek:

how does this work. I've read the whole thread but noone has taken the time to really explain the system, someone please explain it to me....thanks

Also, I might just be imagining this, but didn't i read somewhere that you had to compete with the robot that you check in? If so then you guys wouldn't have the option of using the second bot, right?

Madison

03-03-2003, 16:19

Originally posted by JosephM
But the ball system is more suseptable to slipping compared to the traditional motors/gears/wheels system.

It's no more susceptible to slipping than wheels interfacing with the carpet are.

Jeremy_Mc

03-03-2003, 16:35

You guys keep claiming that this will "inspire other teams". Perhaps to put the extra effort out and raise the bar, yes...but no more than your average joe team would, though.

I don't think they really sparked a new trend in drive trains. They're patenting it anyhow, so it's not like anyone can emulate them.

Personally, (not criticizing) but i think that takes away from the community. Patenting a drive train makes it a little awkward if a team makes a drive system somewhat similar, and then somehow it ends up they sue them over it or something. I'm not saying they would, but if they wouldn't, then why patent?

Odd thoughts yes...but I'm just curious as to why you would do that?

And oh yes...an explanation of the system would be rather cool. I think I have it figured out but it's probably totally off.

one more question, if someone were to pick that end of the robot up, would the balls fall out? or are they attached?

has your patent been applied for? or is it pending? there is a difference...

*jeremy

Jnadke

03-03-2003, 16:41

Originally posted by Gope
How does this work. I've read the whole thread but noone has taken the time to really explain the system, someone please explain it to me....thanks

The omniwheels are like regular wheels but those rubber things on there allow them to spin sideways. If you don't understand how they work, do a search (http://www.chiefdelphi.com/forums/search.php?s=) or ask and I will explain further.

Anyways, the ball portion, if you look at it, is connected to the main drive gearbox, powered by a drill motor. The drill motor drives the ball forward/backward, and spins the omni-wheels forward and backward. Theorhetically it should drive much like a standard 2 wheel drive robot if this was all they had.

However, if you look, the chiaphua motors are on the side of the balls, and spin them sideways, giving the robot a horizontal force. When the robot is at a standstill, if you drive the chiaphuas, the balls will propel the robot sideways. The omniwheels, having those easy-spinning rubber things, will just follow the direction of the balls and will act like a translational drive.

When the robot is moving, and you drive the balls, from the sound of what Baker said, the robot will behave much like a car. It won't move sidways, but the front of the robot will turn to point at a new direction. Basically, it's like stopping with a traditional tank drive, turning to point in a new direction, and going again. The difference is they can do this on-the-fly.

I haven't seen it in action, so I am not positive on this. I am only going off what I see in the picture and what was said.

Originally posted by Gope
Also, I might just be imagining this, but didn't i read somewhere that you had to compete with the robot that you check in? If so then you guys wouldn't have the option of using the second bot, right?

Yes, and no. They do allow you to make your robot modular. You have to pass inspection with every module subset you plan to use in place. Technically, this is one big module in reference to the Robot Controller. I don't really see any difference. Just as long as they can meet Rule K3, under $3500, with both robots then I'm happy.

Originally posted by Jeremy_Mc
Personally, (not criticizing) but i think that takes away from the community. Patenting a drive train makes it a little awkward if a team makes a drive system somewhat similar, and then somehow it ends up they sue them over it or something. I'm not saying they would, but if they wouldn't, then why patent?

I think we have a misconception here on what a patent is. A patent doesn't prevent someone from using an idea altogether. It just prevents someone from benefitting/making money off it. You can still use the design for your use. However, if a company wants to put it into a product and sell it, then they have to pay the TechnoKats.

D.J. Fluck

03-03-2003, 16:42

Originally posted by Jeremy_Mc
You guys keep claiming that this will "inspire other teams". Perhaps to put the extra effort out and raise the bar, yes...but no more than your average joe team would, though.
Like I've said before, every bit counts in the long run

Personally, (not criticizing) but i think that takes away from the community. Patenting a drive train makes it a little awkward if a team makes a drive system somewhat similar, and then somehow it ends up they sue them over it or something. I'm not saying they would, but if they wouldn't, then why patent?
I'll let someone higher answer that one...

Odd thoughts yes...but I'm just curious as to why you would do that?
Please refer to previous answer...

And oh yes...an explanation of the system would be rather cool. I think I have it figured out but it's probably totally off.
You are comming to St Louis, come and see it for yourself

one more question, if someone were to pick that end of the robot up, would the balls fall out? or are they attached?
They are attached

Joe Matt

03-03-2003, 16:51

Originally posted by M. Krass
It's no more susceptible to slipping than wheels interfacing with the carpet are.

You have the motors using a wheel to rotate the ball, interaction 1 that can slip. Then you have a slick ball that rotates on the ground, interaction 2. There are two of the main problem parts.

rees2001

03-03-2003, 16:53

This is what FIRST is all about. I am Inspired. This thread is about Recognizing the Technocats. If you want, I will start another thread where I will recognize the things other teams have done that have inspired me and others like me. Not here. This thread is about 45's moment in the sun. I don't even care if it doesn't work as well as they would like. YOU MADE IT. You may never use it, but you made it. AWESOME. Every year there has been 1 team (sometimes 2) that has done something that really stood out. This year 1 team has done 2 things that stand out.
Thanks guys.

Rob Colatutto

03-03-2003, 17:07

Originally posted by JosephM
I never criticized the Tcats at all. I said I like it. I'm just saying that mabey the effort to build another bot or another drive system could have gone to inspiring another team.

even if another team had inspiration from them instead of them making a second bot (still don't see how they relate) they wouldn't have a moving robot if no one on the team knows how to make it move. i'm hoping the move-less robots will be elimintated this year, should be wtih that tranny FIRST gave every team this year

Madison

03-03-2003, 17:07

Originally posted by JosephM
You have the motors using a wheel to rotate the ball, interaction 1 that can slip. Then you have a slick ball that rotates on the ground, interaction 2. There are two of the main problem parts.

There's slippage all over in a drivetrain. The cumulative amount is what's important. The number of places that slip, when examining things as a system, isn't terribly relevant.

I trust that the TechnoKats have worked out the perceived problems. But, we haven't seen it work at all yet. Like I said originally, maybe it's not really that big of an issue at all. Only time will tell.

I'm interested in learning how they solved whatever problems may have popped up, rather than making it sound like they made some horrible decision. It was their decision, not yours, after all.

Josh Hambright

03-03-2003, 17:10

team 461 would like to say one thing.
WOW!
that is all.

Paul Copioli

03-03-2003, 17:11

As always, I am inspired by what the TechnoKitties have done. Their ingenuity will push our team to do something as clever in the future.

About patents: They are intended to fully share an idea with anyone who wants to know about it. They do not stop anyone from using it. What a patent does do is protect the inventor from having his/her idea stolen. It stops a person or company from financially benefiting from another person's idea.

The original intention for the patent was to establish a record of innovative ideas in order to preserve them. It seems silly with today's technology, but if the only person on Earth who knew how to do this one brand new thing that everyone could benefit from died, that technology would be lost. The patent process helped prevent us from having to "reinvent the wheel" so to speak.

If the TK ball drive is patentable, then I say go for it. If a company sees value in their idea, then they can sell it and use the money for a greater good.

Great job 45.

-Paul

Onizuka

03-03-2003, 17:18

very cool design..and wow:yikes: great job t-kats

Natchez

03-03-2003, 17:27

WOW!

Ideas don't drive technology advancement ... it's those who make ideas reality that drive it. Technokats, way to drive technology and thanks for letting us ride along!

Everyone, don't forget math class ... does anyone know the answer to the following equation?

Ball Drive + Segway =

... AWESOME!

Jnadke

03-03-2003, 17:33

I think some people are giving the TechnoKats less credit than they deserve...

Essentially, this is a true omnidirectional drivetrain. They can go forward, backward, left, and right at will. They can also change the direction their robot points at will. I haven't seen anything this great since the Kiwi Drive (http://stuweb.ee.mtu.edu/~alkrajew/FIRST/). Unfortuantely, you can't really do this without problems because of no 3rd drill motor this year.

With the exception of the Kiwi Drive last year, I've yet to see a team that has a truly omni-directional drivetrain. Now the TechnoKats are added to this 2 team list. Many teams can create the illusion of an omnidirectional drive but they really can only move in 2 directions in any given instant. Swerve drives have to wait for the wheels to re-align. Teams with a 2nd drivetrain that drops down still can't move in a diagonal path, and have to wait for the drivetrain to lower.

I suggest some people read this:

Originally posted by patrickd (http://www.chiefdelphi.com/forums/showthread.php?s=&threadid=16990&perpage=15&highlight=Kiwi%20Drive&pagenumber=2)

I think there is some confusion about drive systems... and locomotion in general.

On a plane (i.e. the surface of the playing field), describing an object's position at any instant in time requires three coordinates. For example, a robot can have an x-location, y-location, and direction (angle) which the robot is pointing. You can not describe the robot's position correctly with less than three coordinates. It is also possible to describe position with polar coordinates and other coordinate systems.

Now, over time, a robot can alter these coordinates. Typically, a robot can move forward and backwards. In other words, it can translate along one axis (move in the direction of the front of the robot). Most robots can also turn at the same time (adjust the angle which their robot is pointing). These two "degrees of freedom" are what you get out of a tank-drive system, which most teams choose to use. The number of degrees of freedom your robot has is defined as the number of coordinates (x-translation, y-translation, and z-rotation) that your robot can adjust simultaneously. A tank drive might be able to turn and translate in another direction, but it can not translate sideways, thus it does not have the third degree of freedom.

Typically, an omni-directional drive system is defined as a drive system with three degrees of freedom. Very few (I can only think of one last year) teams ever have three degrees of freedom. Tank drive only has two. In fact, even if you can turn all your wheels in any direction you like (i.e. swerve drive) you still have only two degrees of freedom, because at any instant in time your wheels are pointed in a given direction, and your robot is restricted to that linear and angular movement, giving you only two degrees of freedom. However, the advantage of the swerve is that you have the ability to change the direction of your prismatic (translational) degree of freedom with respect to your robot. If you can change wheel angles almost instantaneously, your robot is almost as good as one that can go accelerate in any direction at any angle, thus you virtually have three degrees of freedom. Robots that have a set of wheels that drop down perpendicular to your main set also only have two degrees of freedom, since at a given instant in time they can only move in one translational direction and rotate.

Now, a crab-walking robot could be built such that it has three degrees of freedom, but it would be difficult and almost certainly very very slow. The efficiency of an electric motor is far better than the efficiency of a crab-walking mechanism.

There only two mechanical ways I know of to get three degrees of freedom... meaning at any time, you can have any x-acceleration, any y-acceleration, and any angular acceleration. One of these I have posted a brief paper on how to get started on applying it to a FIRST robot (in the white papers) and the other is a little bit abstract and not too likely to work on a FIRST robot. One team had omnidirectional last year, and I forget the number, but I think it was a first or second year team. Basically it entails having three or four omniwheels perpendicular to the center of the robot. With three wheels, each unique combination of independent torques to the three wheels results in a unique direction and angular velocity of the robot.

Challenge for next year: Try to improve upon this drive such that the traction between the ball and the drive wheels can be improved to the point where it rivals a tank-drive robot. If anyone can do this, they would have the supreme advantage.

Joel J

03-03-2003, 17:53

Unbelievable.. and I am not just talking about this awesome robot!

Katy

03-03-2003, 17:56

Originally posted by Andy Baker
The balls are 8" steel "gazing balls" (hollow) that you can buy from a home deco store (we got them for $6 per ball at Homier.com). These balls have urethane molded over them at about a 1/4" thickness. They are about +/- 0.003" out of round. They dent if dropped, and weigh about 3-4 lbs each. They are not inflatable.

So if they dent when dropped what happens if you go up the ramp? Could the rows of dents be a problem eventually?

Jnadke

03-03-2003, 17:58

Originally posted by Katy
So if they dent when dropped what happens if you go up the ramp? Could the rows of dents be a problem eventually?

I think he means dropped from a significant height. The 1/4" thick urethane coating, which he mentioned, would absorb any small forces acting on the balls.

Rickertsen2

03-03-2003, 18:21

Hmm i have played with an idea like that in my head before. Its kinda like the opposite of a mouse. What is the exact status of ur patent. Are u sure this hasn't already been patented. What type of patent are you applying for?

AWESOME WORK!!!

Molly Menges

03-03-2003, 18:22

all i can say is...you had to wait until after i left didn't ya?? grr...

Clark Gilbert

03-03-2003, 18:39

Prototype: Here is the prototype Andy talked about. This picture was taken the night of kickoff.
http://www.pictars.com/032003/DSCF1676.JPG

While I think this is great and very cool, I just wonder if this years task was so simple that we can afford such lavash things. What about other teams who can barely move? Were the TechnoCats right to spluge on their drive while many teams still don't move?

We do help people, by donating our robots to other teams, and by producing our "white papers" that we post here every year.

http://www.firstrobotics.net/03gallery/images/1024-1_jpg.jpg

Slipping/Traction: Traction really wasn't meant to be an issue with this robot. Sure it needs some traction to push a stack around or move around, but it's meant to avoid situations where high amounts of traction are needed. Trust me, you probably wont see this robot trying to push anyone off the top of the ramp. :D

Like Andy said, hopefully our main robot does well enough (like we have much doubt in it), but if a perfect alliance could be made by using the ball drive, I'de bet we'de be all for it.

If you want to see the Mighty Mouse, come to our pit at St. Louis, Pittsburgh, Midwest Regional, or the Championship and you will be able to either drive it (if there are not too many people, or see a demonstation of it by someone).

:D

Austin

03-03-2003, 18:43

I think he means dropped from a significant height. The 1/4" thick urethane coating, which he mentioned, would absorb any small forces acting on the balls.

Yes, there is a very dented ball at the shop that we play around with sometimes, and try to dent it further. To put any significant dent at all in it you must THROW it down pretty darn hard. :)

Beast314

03-03-2003, 19:11

Well done. This will give me another thing to check out in the pits at St. Louis. I have also worked on a similar idea in the past along with a few classmates, using a much smaller wheel though. The idea was lost in the wind when we saw no use for that type of system last year, but I'm glad to see a workable variation of it.

Mimi Brown

03-03-2003, 19:28

wow. thats all i have to say. oh yeah...and i cant wait to see it in pittsburgh! :D

abeD

03-03-2003, 20:03

i remember someone in the thread saying that they saw a video of that, is there any way we can get a link to some type of video?(especially for those of us that won't get to see it in person)

Cory

03-03-2003, 20:25

Originally posted by JosephM
Why not take some of the money that would have gone to building another bot or a more complicated drive system and give it to a struggling team or a new team? [/B]

How far would 700 bucks really get you towards helping another team?

TechnoKats: super cool. Im amazed that you could pull that off. I hope I end up at Nats and can see that baby work.

My Hat is off to you =)

Cory

Ricky Q.

03-03-2003, 21:18

Andy, Clark, DJ and all the TKats

Sweet! I had everyone around me in my History class (when we we're typing an essay test :p) just amazed, I think it made some of them consider joining the team :D....Excellent job, as we've all come to expect...I'm looking forward to looking it over and seeing you all in Evanston....

We all tip our cheeseheads to you :p

Clanat

03-03-2003, 21:24

Congratulations on a very innovative design! I want to see this thing in action now :)

Clark Gilbert

03-03-2003, 21:50

I'm not personally going to post any video of the ball drive till after the Pittsburgh regional. Having 2 regionals in the next 2 weeks makes me very busy, along w/ various school work. There is video, and there will be video. For now you will just have to enjoy the pictures. Sorry

Joe Matt

03-03-2003, 21:51

Originally posted by Cory
How far would 700 bucks really get you towards helping another team?

TechnoKats: super cool. Im amazed that you could pull that off. I hope I end up at Nats and can see that baby work.

My Hat is off to you =)

Cory

AHAHAH!!! I like it too, it's just that mabey they could....

oh, forget it...

Ellery

03-03-2003, 21:57

Andy and Team #45,

My hat goes off to you guys once more being the drives fanatics that you guys tend to be year after year! It's definitely an interesting design that's worth investing extra resources if available. Especially this year's game definitely pushed our team to chose the extreme end of simplicity compared to our extreme complexity we had last year. As long as it keeps students involved and free from boredom it's a great excuse to make.

See you guys soon!

Ellery W.

Dima

03-03-2003, 22:21

well actually this is probably the BEST soluction to this years game: Have two robots each one optimized best for what its supposed to do!

Technokats i think it Will be woth it for you to buy another controll system and a set of motors so that before any given match you can have a choice of what to bring to your alliance!

Imagine being paired with another good kind of the hill robot. Obviosly your alliance need to have a box stacking bot to make that optimal stack. so you just put your other bot in that match!

now that you have both bots if i were you i would do just that!

Oh thats aside from the point that you win the Xerox Creativity Award! (or at least have very high chanses to do so)

Andy Baker

03-03-2003, 22:45

OK... I'll try to answer some questions and explain some things further.

First of all... the patent.

Our management here at Delphi saw the prototype of this design and strongly suggested that we patent this design... not to protect us from other FIRST teams to use, but rather future companies. This will be a Delphi patent, once it goes through it's process. Currently, it is a "record of invention", and we are protected to show it to the public.

Natchez is wise. The biggest reason we are looking to protect ourselves is for the use of something like the Segway. Imagine a one-ball balancing Segway. This is exactly why our management wants us to protect it. We currently have an agreement with Segway (of the details, I have no idea) that encourages Delphi to help develop technology for the Segway... so this is a good thing (every Segway has about $400 of Delphi electronics in it).

Rickersen2 - you are exactly right... it is the opposite of a mouse. This is the easiest way to explain it.

JosephM - you are right also. Your concern about the 2nd level of friction loss is very valid. This is really the biggest hurdle of this design. The fact that the small drive wheel has friction losses to the ball and the ball has friction losses to the floor is not trivial. This makes the "ball drive" definitely not a very efficient mechanism. Our prototype would stop and start because of these losses (and an out of round ball). JosephM - your questions are valid, and you have good points. I appreciate your comments.

Katy - the balls dent if we drop them from about waist high, but they have not dented while driving up the ramp. If we ran into a 4x4 at full speed, they might dent... but we have not tried that yet.

Ricky - it is great to hear that other people might get on your team by seeing this. If find that suprising, but if it is true, then our goal for this drive base has been achieved.... it's all gravy from here.

M.Krass and others - I am not sure what you mean by the stall issue. This device works REALLY well when both small drive wheels are moving. The urethane ball drives nicely at a 45 degree angle, but it drives less efficiently at 0 degrees or 90 degrees. It works, but has less power. Also, at straight forward or backward, the lateral drive wheel does not spin. The main reason we decided to do this was to use the shifting gearbox for the front & back drive direction. Optimally, we would rather use 4 gearboxes (one on each aluminum drive wheel) and have each drive wheel positioned at a 45 degree angle. That way, if both wheels are turning, the robot will go straight forward and backward. But, we could not afford (weight, cost, time, etc.) 4 gearboxes. Thanks for your comments.

Dima - good ideas... but FIRST has alot of rules against this. Update #4 was a killer. It really set us back. There is actually a post on the FIRST Q+A forums that says a team should not re-deploy a motor to another subassembly, even if it is the same motor (and not a spare). This ruling is ridiculus, in my opinion. We will abide by the rules, but we will need explainations.

For the rest of you: thank you. Come by our pit, and I will introduce you to the guy who came up with the main part of this design: Mark Koors. He told me of this idea last summer and I simply laughed at him. My first concern was the same as JosephM's (the 2 levels of friction issue). But... the more Mark and I worked the issues, the more they cleared up and the simpler the design got.

Simplicity - Krass is right... this omnidrive is extremely simple, not only in the mechanics, but especially in the software. No chain linked axis turns, no lookup tables... simple. You who are wrestling with crab drive software/hardware would cry to see how simple this is (yet another reason to patent it).

More to come... sorry about rambling. I surely did not heed my own words to be concise.

Andy B.

Ryan Albright

03-03-2003, 23:04

how does the balls work ont he ramp are you shure the ramp wont puncture them caust he ramp ripped apart are wheels from last year

Madison

03-03-2003, 23:10

Originally posted by Andy Baker
M.Krass and others - I am not sure what you mean by the stall issue. This device works REALLY well when both small drive wheels are moving. The urethane ball drives nicely at a 45 degree angle, but it drives less efficiently at 0 degrees or 90 degrees. It works, but has less power. Also, at straight forward or backward, the lateral drive wheel does not spin. The main reason we decided to do this was to use the shifting gearbox for the front & back drive direction. Optimally, we would rather use 4 gearboxes (one on each aluminum drive wheel) and have each drive wheel positioned at a 45 degree angle. That way, if both wheels are turning, the robot will go straight forward and backward. But, we could not afford (weight, cost, time, etc.) 4 gearboxes. Thanks for your comments.

Andy B.

Andy, thanks for taking the time to answer so many questions :)

"Stall" was probably the worst choice of words in the history of the English language, but I still can't come up with anything better. I guess that's what happens when you're discussing something that's never been seen before.

Akin to what you mentioned to JosephM. . . .there exists the possibility that the losses in the two unique components of the drive train aren't equal. That is, whatever losses the omniwheels experience in the gearing, chain, sprockets, contact with the carpet, etc. may not be equivalent to the losses that exist in the ball mechanism; the six points of contact on each ball, the gearboxes, etc.

As the ball's forward rotation is tied to the omniwheels rotation since they're in powered by the same gearbox, I was wondering how you accounted for any imbalance in losses that might exist. After all, if there are more losses on the ball than there are in the omnwheel, wouldn't it spin slower? ...and then, wouldn't it just be dragging and do nothing to "power" the robot?

It just seems like whenever there exists a chance that one "wheel" in a side of 4WD drive system might turn slower than the others, it'd be better off to make that "wheel" unpowered, or otherwise find some way to balance the losses so that they all spin at the same speed.

Does that make more sense?

Dima

03-03-2003, 23:12

andy!

i look at update 4 and it seems to me that those rules apply only to the robot currently on the field.

...meh doesn't matter if the need is there you can always swap stuff.

P.S. if there a chanse you could come by Silicone Valley Regional with that robot?

nickma

03-03-2003, 23:19

Thanks to you guys my plans for getting work today went out the window. My afternoon plans where to complete the 3 days of school work I would be missing in order to attend BAE but that went out the window when I saw the new 45 drive. I just had to stare at it for sometime to get an idea on what it was and appreciate what it did.

Again my hat goes off to you, as another big stride in drive systems is achieved this year.
Congrates.

Andy Baker

03-03-2003, 23:27

Originally posted by M. Krass
As the ball's forward rotation is tied to the omniwheels rotation since they're in powered by the same gearbox, I was wondering how you accounted for any imbalance in losses that might exist. After all, if there are more losses on the ball than there are in the omnwheel, wouldn't it spin slower? ...and then, wouldn't it just be dragging and do nothing to "power" the robot?

Does that make more sense?

I really don't know. We have no efforts in evaluation yet. Our prototype had casters, not extra omni-drive wheels. Koors is currently on a mission trip to Hati... when he gets back, he may be able to explain this better than I can.

I see the omniwheel as a power boost, and it only helps the ball drive go forward and back with another contact point.

For instance, when the ball hits the ramp grating, the omniwheel gives the frame more power to push up the ramp. Once the robot is level on the ramp again, then all 4 points of contact are again propelling the 'bot.

There is a slight speed imbalance between the balls and the omniwheels... we are not sure how this affects performance. If the speeds/losses were better matched, I am sure that it would run a bit better. At it's current setup, it does run pretty well and I don't think that we are seeing the "stall" problem that you are describing.

Andy B.

Tony

04-03-2003, 03:09

Words do not do the TechnoKats justice.

Years past, you've ALWAYS been one of my favorite robots. My favorite robot of **ALL** time was your Huge Freakin' Arm of 99 (TKO). That thing could destroy anything in its path.

Now you throw TWO beauties at me to choose from.

Question: My memory is hazy, but the arm on Mighty Mouse brings back memories of the Huge Freakin' Arm of 99. Are there many//any similarities there?

And since there are a number of people that seem to be confused and seem to believe that this is the post where you go to shamelessly plug yourself and your team and your personal 'wondrous' ideas you didn't have the balls to run with (like the TechnoKats did) :

This thread belongs to the TechnoKats.

Fear them.

EXAMPLE OF WHAT DOES BELONG HERE:

TechnoKats, you guys are astounding. I will spend as much time as possible in your pit at Midwest gaping in dumb awe.

You guys and what you've done this year is everything FIRST is supposed to be about.

I can only pray to once again see the wonderful sight of 45 and 111 side by side.

See you at Midwest.

Rock on.

FotoPlasma

04-03-2003, 04:45

Mad props to 45.

This has to be the most interesting concept turned into reality that I have ever seen.

I'm going to need to see video of this thing in action.

Keep up the great work. And that goes for everyone.

:D

<edit>
Oh, one more thing... I want to see the code for driving this thing...
;)
</edit>

Steven Carmain

04-03-2003, 13:38

The program was thrown together at the last minute. The program is just a simple tank drive code with 2 sticks, and if you move the right stick left and right, it gives you sideways movement

Dr. Bob

04-03-2003, 17:41

So as everyone has said. The Ball drive system is real impressive. Must be awsome on the feild. But thats just the base. How much can that little claw really do?

Clark Gilbert

04-03-2003, 18:54

The arm operates just like any other arm (it's similar to the 1999 arm with less joints). It's meant to be a stack destroyer and that's it. I'm guessing it could try to remove 1 tote to lower the multiplier or it can swing and wipe out 1/2 or all of the stack. For a sure method of removing the whole stack it can grab under the lip of the bottom tote with the lexan attachment at the end. Once it's under the lip it lifts and topples the stack.

gsensel

04-03-2003, 20:43

As a past member in the team I am impressed with what I see in this and the other parts of the team.

soezgg

05-03-2003, 14:48

i agree, very cool system, even if you dont get to use it.

my question: why would you patent it, and what purpose would that serve?

Steven Carmain

05-03-2003, 15:19

Originally posted by soezgg
my question: why would you patent it, and what purpose would that serve?

As it says earlier, the reason we patented it was so companys like Segway take our design and make a one ball Segway. It just stops companys from making money on our design.

Beast314

05-03-2003, 15:24

I must say I don't know if we'll see a ball driven Segway, but it's never a bad idea to patent ideas. I only wish I would have done that with ideas I've had. I can't wait the less than 24 hours to check out you're bots.

Gadget470

30-03-2003, 10:23

Sorry to bring up a dead thread but I think it's appropriate.

Originally posted by JosephM
While I think this is great and very cool, I just wonder if this years task was so simple that we can afford such lavash things. What about other teams who can barely move? Were the TechnoCats right to spluge on their drive while many teams still don't move?

Just a question.

Well Joseph, as was witnessed this weekend at the Midwest Regional. The technokats splurging provided another team which couldn't move a chance to play.

The technokats would have done it anyways, as they already had prototypes made. They just needed to start it's build post-kickoff if they were to want to compete with it.

I feel that if a team can afford it and it's of use to someone less fortunate, they should definitly build or use whatever it may be. The teams who blow thousands just so they have something neat.. well I don't like seeing those.

The technokat's once again showed the meaning of FIRST. An Ispiring new development in the Science and Technology field, and backing it with Gracious Professionalism.