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.

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.

IR-controlled autonomous mode knocks trackball off overpass.

Hurdling demonstrated during driver tryouts.

Hurdling again during driver tryouts.

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?

[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!

[Madison]

Originally Posted by 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!

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 . 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]

Originally Posted by 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!

Originally Posted by 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.

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]

Originally Posted by 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

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.

Originally Posted by 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!

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]

Originally Posted by M. Krass

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


looks incredible. best of luck to you!