FRC488 - team xbot presents X8: The Ocho

[Madison]

This has been a fantastic build season for our team and we're proud to present our 8th robot, X8: The Ocho.

http://fsayre.smugmug.com/photos/256377117_eVygB-XL.jpg

Overall --


Achieves all game functions - hurdle, herd, possess, remove from overpass and place on overpass.
118 lbs., 58" tall
Bumpers cover 68% of perimeter
Remains upright until tipped to approximately 60* off horizontal in all directions -- with ball and elevator extended to maximum height.
Physically incapable of violating <R16>
We've had approximately 20 hours of drive testing, 10 hours of elevator testing.
Most sophisticated sensor package in team history
IR-based hybrid functionality


Drive System --


6WD
4" Traction Wheels in the center, custom-built 4" omni wheels on each corner for fantastic maneuverability
3-speed, shift-on-the-fly Dewalt XRP transmissions
~12 ft/sec top speed
24:1 low-speed gear ratio
Screw-based chain tensioning system


Inclinator --


Inclined at 15* to move trackball mass above robot as its height increases
~74" travel
PID-based position control with three preset positions -- bottom, "descore" and top -- and fine adjustment.
Electronically controlled braking slows descent
Cascade-style cable rigging moves each stage simultaneously, maximizing overlap for best support possible
Driven by two CIM motors through AndyMark Toughbox transmission at 12.75:1 ratio. Inclinator is powered both up and down by 3/32" steel cabling tensioned by turnbuckles.
Redundant cabling increases reliability
Linear bearing surfaces are a hybrid of custom-made HDPE linear slides and 80/20 system nylon rollers on oil-impregnated bronze bushings.
Pneumatic tubing take-up reel insures proper management of tubing to Ball Manipulator



Ball Manipulator --


Simple forklift-inspired design
Can be used as a secondary mechanism to remove ball from overpass
Pneumatically-actuated tipping action secures ball against Inclinator
Can pick up ball on the fly
Passive hurdling action requires no coordination between operator and driver, increasing scoring efficiency
We have prefabricated two spares with more on the way


Sensor Package --


Encoders in line with drive system for PID-based position and velocity management. Accuracy is +/- 1" over 24'.
Encoder mounted to winch drum for PID-based position and velocity control
Brake/Coast settings on Victor 884 Speed Controllers driving winch are controlled by encoder-based position feedback and allow faster-than-gravity descent of Inclinator while minimizing sudden impact at the end of travel.
Limit switch at bottom of Inclinator travel zeros encoder value to eliminate drift and acts as safety override in case of encoder failure.
Limit switch at top of Inclinator travel acts as safety override in case of encoder failure.
IR-board is mounted to bracket with two degrees of freedom that gives flexibility in starting position while maximizing signal readability.
Pressure switch allows automatic control of compressor power.


Controls --


One XBox 360 controller each for driver and operator
Driver has control of motion and gear shifting; operator controls Inclinator position and Ball Manipulator position
Software intelligently switches between simulated "Ackerman-style" steering and rotating in place, allowing fast lap times and fine control for ball retrieval.
IR-based hybrid controller tells The Ocho which Overpass position contains our trackball; fourth function is "abort".
Matlab-based trajectory generation software takes way point and heading information and generates hybrid movement code automatically.
"Crossing" macro releases and retrieves ball while crossing the finish line, adjusting timing as necessary based upon robot speed and direction.


Video --

Early test of Inclinator with abandoned claw. (http://www.youtube.com/watch?v=DsFPSC1IvPk)

IR-controlled autonomous mode knocks trackball off overpass. (http://www.youtube.com/watch?v=kvTlinvhaDc)

Hurdling demonstrated during driver tryouts. (http://www.youtube.com/watch?v=CmZDC7tkPyQ)

Hurdling again during driver tryouts. (http://www.youtube.com/watch?v=PLbfkFha7-M)

We're looking forward to competing in Portland, OR, Tacoma, WA and at the Championship in Atlanta, GA.

Please, ask questions! We're enormously proud and would love to talk about all of the amazing features this robot contains. How many other robots can say that they have a functioning tailgate, after all? :)

http://gallery.diddly.com/d/13078-2/ocho1.jpg

[waialua359]

Very nice and impressive. I like the paneling.
What's the material, who did the printing and how much was that?
We've always had our own sticker cutter and used very thin polycarbonate to make our team # and signs, but I like yours much better!:D

[Madison]

Very nice and impressive. I like the paneling.
What's the material, who did the printing and how much was that?
We've always had our own sticker cutter and used very thin polycarbonate to make our team # and signs, but I like yours much better!:D

Thanks!

The side panels are 1/16" polycarbonate sheet. We designed the graphics in Adobe Illustrator CS and plotted them on our lab's HP DesignJet plotter, then glued them to the interior of the polycarbonate sheet.

A 4x8' sheet of 1/16" polycarbonate was about $75+tax. The ink was free. :)

[EricVicenti]

Team 8 forgives you for using that name :D. See you at Portland next week.

[waialua359]

Wow! Our panels are actually 1/16" polycarbonate sheets also but with just stickers on them.
What's the material used, printed from the plotter. I actually have 2 HP plotters also. But we use them to make either bond paper or canvas banners at regionals and other events.

Thanks.

[Madison]

Very nice and impressive. I like the paneling.
What's the material, who did the printing and how much was that?
We've always had our own sticker cutter and used very thin polycarbonate to make our team # and signs, but I like yours much better!:D

Wow! Our panels are actually 1/16" polycarbonate sheets also but with just stickers on them.
What's the material used, printed from the plotter. I actually have 2 HP plotters also. But we use them to make either bond paper or canvas banners at regionals and other events.

Thanks.

It's a medium-weight semi-gloss paper. I'm not too sure about much more than that, but I'll try to check the next time I'm in the lab -- but that may not be before this weekend since I'm a bit tired of looking at the machine shop. :)

[waialua359]

Madison,
Thank you so much. Since we have HP plotters also, if you can get the product # of the paper, we would appreciate it so much!
No rush of course, as we are tired of looking at our shops too.

We leave late next week traveling to consecutive East Coast regionals and driving to both of them from Baltimore. We have to drive 3 1/2 hours right after flying for 15 hours (with stopovers) to get to the VCU regional area.
Too bad I'm the lead driver.:(

If your going to Championships, I will definitely look for your team and stop by your pit.

Good luck this season, even though you folks dont need it.

-Glenn

[Vikesrock]

That's a really nice looking robot! If it works half as good as it looks (and the video suggests that it might) 488 will definitely be a strong competitor at any event you attend.

Nice work!

[SorcererSupreme]

488!

[Madison]

Madison,
Thank you so much. Since we have HP plotters also, if you can get the product # of the paper, we would appreciate it so much!
No rush of course, as we are tired of looking at our shops too.

We leave late next week traveling to consecutive East Coast regionals and driving to both of them from Baltimore. We have to drive 3 1/2 hours right after flying for 15 hours (with stopovers) to get to the VCU regional area.
Too bad I'm the lead driver.:(

If your going to Championships, I will definitely look for your team and stop by your pit.

Good luck this season, even though you folks dont need it.

-Glenn

We'll keep an eye out for you in Atlanta. We're already registered and looking forward to it.

Are you flying into Baltimore-Washington Airport? Richmond shouldn't be more than two hours in good traffic, if I remember correctly. It's been a long time since I've made the drive and it's undoubtedly slower when you've got carloads of people, but it was a pretty easy, if uneventful drive. Of course, I've never done it after a fifteen hour day of flying.

I'll never complain about our three hour ride to Portland again. :) Thanks for the wishes of luck. We try to minimize its importance, but having it on our side is never a bad thing.

That's a really nice looking robot! If it works half as good as it looks (and the video suggests that it might) 488 will definitely be a strong competitor at any event you attend.

Nice work!

Thanks! We've had a lot of time to run this robot into the ground and iron out any bugs, so it's become quite reliable. We're excited to see how it will stack up against the competition, but we're confident that we're in for a good season.

[MasterChief 573]

This robot is probably the most reminiscent to our teams that I've seen yet. Designing the perfect forklift mechanism is hard, but we think we have come pretty close. Awesome robot, hope it does great.

[JesseK]

IR-based hybrid controller tells The Ocho which Overpass position contains our trackball; fourth function is "abort".
Matlab-based trajectory generation software takes way point and heading information and generates hybrid movement code automatically.
These are my kind of engineers!

How many travel stages are in your elevator?

[waialua359]

We'll keep an eye out for you in Atlanta. We're already registered and looking forward to it.

Are you flying into Baltimore-Washington Airport? Richmond shouldn't be more than two hours in good traffic, if I remember correctly. It's been a long time since I've made the drive and it's undoubtedly slower when you've got carloads of people, but it was a pretty easy, if uneventful drive. Of course, I've never done it after a fifteen hour day of flying.

I'll never complain about our three hour ride to Portland again. :) Thanks for the wishes of luck. We try to minimize its importance, but having it on our side is never a bad thing.



Thanks! We've had a lot of time to run this robot into the ground and iron out any bugs, so it's become quite reliable. We're excited to see how it will stack up against the competition, but we're confident that we're in for a good season.

Thanks for the headsup in Virginia. We were told that it was 3 hours to drive.
We actually drive from Seattle to Portland every year the past 5 years for an electric vehicle competition in late May early June. I did it in a record time 1 hour 47 minutes from Safeco field onramp to vancouver, WA one year because it was late after a baseball game with no traffic.....going fast.

[pyxelz]

Looks great - especially the paneling!
good luck from 973

[flamefixed]

first off, i do hope great minds think alike! haha. heres why -

we are sporting a lift, leaning backwards to keep the mass of the ball central over the bot, cascade style belting, driven up AND down with two cims by an entirely fabricated gearbox and a combination of delrin and 8020 rollers and t slots. (though are entire "guillotine" we call it, is made from 8020 stock.

many similarities. puts my teams mind at ease about our design more :p


looks incredible. best of luck to you!

[synth3tk]

What's the overall length of your robot? We apparently made our base too long to implement an arm correctly.

Otherwise, awesome job! Good luck at your competition.

[ladkahaidesi]

WHAT TIME IS IT?!?!?!?!?

[MasterChief 573]

first off, i do hope great minds think alike! haha. heres why -

we are sporting a lift, leaning backwards to keep the mass of the ball central over the bot, cascade style belting, driven up AND down with two cims by an entirely fabricated gearbox and a combination of delrin and 8020 rollers and t slots. (though are entire "guillotine" we call it, is made from 8020 stock.

many similarities. puts my teams mind at ease about our design more :p


looks incredible. best of luck to you!

GIVE IT UP FOR DELRIN!!! Thats the material we used to build our cams that manipulate our fork while being lifted.

[Madison]

What's the overall length of your robot? We apparently made our base too long to implement an arm correctly.

Otherwise, awesome job! Good luck at your competition.

The robot is about 78" long with the forks and inclinator in their lowest position.

GIVE IT UP FOR DELRIN!!! Thats the material we used to build our cams that manipulate our fork while being lifted.

A significant percentage of our robot is plastic, with much of that being delrin.
Our omniwheels are largely delrin, as are all three encoder mounts.
Bearing blocks in the drivetrain are a mixture of delrin and polyethylene. Pulleys on the inclinator are each a combination of delrin, ABS and polycarbonate, while the winch drum is made from polycarbonate, delrin and polyethylene.
Ball manipulator gussets are all polycarbonate, while it has polycarbonate ball stops and polyethylene skids.
Electronics are mounted to ABS
Dewalt XRP pinion is mounted to CIM shaft with delrin
Spacers everywhere are delrin
Linear slides on inclinator are polyethylene, rollers are nylon.
Pneumatics are mounted polycarbonate, tubing take up reel is polycarbonate, ABS and delrin.
IR board is delrin and acrylic.


...that's off the top of my head. There're probably many other things I'm forgetting. We love plastic.

[octothorpe]

Very nice robot – a truly elegant job on the paneling, and a design that's clearly very capable at the game. Sounds like a phenomenal sensor package too, I wish we had that kind of intelligence on our robot. My only qualm is at your mention of redundant cabling... because our elevator lacks it. Not that we had room for the extra weight anyway :o . Good luck and 766 will hope to see you at Championships!

[EricVicenti]

The robot is about 78" long with the forks and inclinator in their lowest position.

Will that fit inside the 80" cylinder?

[Blue_Mist]

WHAT TIME IS IT?!?!?!?!?

488!!! Many fond memories at Silicon Valley last year, and hopefully we'll see you again in Atlanta!

Beautiful robot. I like the tipping back, which I haven't seen yet this year. I only have one item to point out. How are you on other robots knocking into Ocho, either tipwise or possibly knocking the ball out?

[Vikesrock]

Points from the last two posts appear to be clearly addressed in the robot stats that were posted


# Remains upright until tipped to approximately 60* off horizontal in all directions -- with ball and elevator extended to maximum height.
# Physically incapable of violating <R16>

[Squirrel Lord]

You know what? I come home after school and start to scout for Portland. Now its a few hours later and I check Chief Delphi again to see if I can glean any more information for my report. And look, 488 gave me the best present of all: good information. Very good information actually!:yikes:
Thanks a bunch!
:D

[Madison]

Very nice robot – a truly elegant job on the paneling, and a design that's clearly very capable at the game. Sounds like a phenomenal sensor package too, I wish we had that kind of intelligence on our robot. My only qualm is at your mention of redundant cabling... because our elevator lacks it. Not that we had room for the extra weight anyway :o . Good luck and 766 will hope to see you at Championships!

Thanks! :) We've never had so many sensors on a robot before; in fact, I am not sure if we've ever had sensors on a robot in the last three years. We knew early in the season that we could build mechanical systems to do everything we needed, but also that success this season was going to be largely based on good control systems. We've tried to do everything possible to give our programming team the feedback and access they've need to generate our software, and while I'm sure they might've liked a bit more time, they've done an amazing job.

Will that fit inside the 80" cylinder?

Yep!

http://img47.imageshack.us/img47/6058/r16uj6.jpg

488!!! Many fond memories at Silicon Valley last year, and hopefully we'll see you again in Atlanta!

Beautiful robot. I like the tipping back, which I haven't seen yet this year. I only have one item to point out. How are you on other robots knocking into Ocho, either tipwise or possibly knocking the ball out?

Y'all were fantastic alliance partners and I wish we could make it down there again to make another run at a win.

The robot is pretty stout. The forks are, by design, expendable in some capacity -- and very easy to replace. We have two spares fabricated already with plans for three more.

It's pretty challenging to tip the robot. Our biggest fear is being clotheslined by the overpass while being illegally pushed from behind. While there's a penalty for that behavior, we have no expectation that faster robots will be well controlled.

The ball is pretty well corralled, also. We have some ability to vary the extent to which the forks tip the ball back against the robot, so if it turns out that we're dropping the ball frequently, we'll hold it tighter against our frame.

You know what? I come home after school and start to scout for Portland. Now its a few hours later and I check Chief Delphi again to see if I can glean any more information for my report. And look, 488 gave me the best present of all: good information. Very good information actually!:yikes:
Thanks a bunch!
:D

No problem! I can't wait to see your robot this season -- do y'all have any pictures?

We know how important it can be to have good information and, while there are some things about robot and strategy that we considered to be loosely "proprietary," we hope that by sharing as much information as possible, we'll encourage others to do the same. Ignorance doesn't typically benefit anyone.