Statistics on top 20 teams?

[Chris is me]

Fun Fact: Just looking back through 2005 (before that "no one" had mecanum), there has never, ever, ever been a mecanum drive robot on Einstein. I hope teams that consider mecanum in future years ask themselves why they think this is.

[Peter Matteson]

Originally Posted by Chris is me

Fun Fact: Just looking back through 2005 (before that "no one" had mecanum), there has never, ever, ever been a mecanum drive robot on Einstein. I hope teams that consider mecanum in future years ask themselves why they think this is.

We said the same thing about wide bodies and Einstein in 2009 and 11 out of 12 robots were widebody that year.

Just because the game where mechanum makes sense hasn't happened yet doesn't mean there will never be one. It's a simple design trade that you can do when determining your team's strategy. Just because you can make something does't mean you should if you look at the big picture.

[Chris is me]

Originally Posted by Peter Matteson

We said the same thing about wide bodies and Einstein in 2009 and 11 out of 12 robots were widebody that year.

Just because the game where mechanum makes sense hasn't happened yet doesn't mean there will never be one. It's a simple design trade that you can do when determining your team's strategy. Just because you can make something does't mean you should if you look at the big picture.

I didn't mean to imply "never will there be one" or "mecanum is always bad". I just think when teams make such a decision, they should ask themselves why this year will be different than previous years.

[thefro526]

Originally Posted by Chris is me

Fun Fact: Just looking back through 2005 (before that "no one" had mecanum), there has never, ever, ever been a mecanum drive robot on Einstein. I hope teams that consider mecanum in future years ask themselves why they think this is.

Oh, and my favorite Fun-Fact: There has only been one 6WD Swerve Drive in the history of FIRST... And it went to Einstein.

Also, there have been a quite a few flop bots on Einstein as well: 71 in 2002, 67 in 2004, 67 in 2005, and 16 in 2008. Looks like they've been spaced out an average of 2 years each... Does that mean we're overdue for a Flop bot to go to Einstein? Hopefully they're legal in 2011.

[Chris is me]

Originally Posted by thefro526

Oh, and my favorite Fun-Fact: There has only been one 6WD Swerve Drive in the history of FIRST... And it went to Einstein.

Also, there have been a quite a few flop bots on Einstein as well: 71 in 2002, 67 in 2005, and 16 in 2008. Funny thing is that they've been spaced out 3 years each... Maybe we'll see a flop bot on Einstein in 2011?

You forgot 67 in 2004, which kind of wrecks your pattern a little.

[thefro526]

Originally Posted by Chris is me

You forgot 67 in 2004, which kind of wrecks your pattern a little.

I edited my post to reflect this.

Hopefully the rules won't be overly restrictive and flop bots will be legal next year.

[Peter Matteson]

Originally Posted by Chris is me

I didn't mean to imply "never will there be one" or "mecanum is always bad". I just think when teams make such a decision, they should ask themselves why this year will be different than previous years.

That was my point as well.

[Joe Ross]

We used LabVIEW. We did most of the work in telop this year, as we didn't have any control loops. Last year, we mostly used telop to set set-points and ran the control loops in periodic tasks (separate thread).

Our autonomous was structured into discrete VIs that had their own while loop in each one running from autonomous independent. We could then string these VIs together very much like lego programming. For example, we had a drive until ball detected, followed by a kick, followed by drive until ball detected in parallel with wait for 2 second kick retract. It was very easy to move those around as needed.

We had no problems with WPILib. We used Jaguars for most things with PWM control. Programming computers were team supplied.

The only sensor we used in competition was an analog current sensor on our ball herder to detect when a ball was captured. We played with the vision system and had it tracking at home, but didn't have a chance to integrate it into the rest of our code. We used the tracking part without modification, but changed the auto-aiming to fit the rest of the structure of our code.

We had 4 wheel, 4 CIM motor drive, with two pneumatic tires and 2 omni-wheels. Frame was aluminum tube, welded. Almost all fabrication was manual. Kicker was completely pneumatic using a pre-charged cylinder. We did hang, from the top bar There are no wenches on our team or robot (no winches either). We used a lead screw powered by a CIM to hang. We had a single powered roller on top, and an un-powered roller on the bottom that the ball spun against.

We did a custom LabVIEW dashboard, but we only used a little for debugging, and not really in a match. We only used the kit joysticks. After having problems with the provided hub during build season, we bought our own USB hub. We did not use the cypress.

Most of the problems that I helped other teams with were with loose wires, so make sure everything is tight, and that you periodically check your wires, especially in a high impact game like breakaway.

[Ether]

Originally Posted by slavik262

We had a huge bug with the watchdog tripping this year because our extra threads were hogging too much CPU time.

Would you please elaborate on this? What exactly was the bug?

Originally Posted by slavik262

you can play around with task priority or cause your tasks to sleep when they're not needed to make up for it in performance (i.e. have a task that updates your PWM outputs sleep the length of the Victor/Jaguar update speed).

Can you give a couple of examples of 2010 FRC breakaway functionality which would require (or even benefit from) changing task priority?

In the 2010 FRC LabVIEW framework, all user-created periodic tasks have the same priority, and they are preemptively time-slice multitasked by the O/S. Running these periodic tasks at a reasonable rate, as you suggested, frees up the CPU so that it should have enough throughput to service all the tasks you need, no?

~

[Tom Bottiglieri]

Programming

What language did they use?
C++

Threaded code or just poll in the teleop loop?
We just did everything sequentially in the TeleopPeriodic calls from WPILib.

Did they do something in autonomous? If so, what worked?
Our auto mode was set up so you could select a "main" and secondary function. Main functions included :
- Far Zone, Kick 3, With Bounce
- Far Zone, Kick 3, No Bounce
- Mid Zone, Kick 2, Straight on'
- Mid Zone, Kick 2, From Angle
- Near Zone, Wait and plow
- Do Nothing

Secondary Functions Included:
- Cross Bump and kick (5 ball mode)
- Cross Bump and wait
- Cross 2 bumps
- Block the tunnel
- Back up and drive to center of field (to steal opponents missed shots)
- Do Nothing

The secondary functions were smart enough to know what to do based on the first function... so 'Block the tunnel' worked from the far zone and the middle zone without having to explicitly tell it to. Everything worked. We kicked 5 balls in auto many times and made 3 from the far zone a few times.

What problems did you encounter, if any, with WPILib?
None. It seemed solid.

Did you download the sources and rebuild WPILib/CanJaguarLib?
No.

CAN or PWM control?
PWM. We only used IFI Victor speed controllers.

Did you use the Classmate for programming your robot or student/school supplied computers?
We did not use the classmate for development.


Robot Design

What sensors were used?
- Encoder on drive for distance measurement/control
- Yaw gyro for angular control and "drive straight" correction
- Pitch gyro for controlling the autonomous bump traversal
- Encoder on kicker to control winch for multi-distance kicks
- Encoder on ball grabber to sense when we had control of a ball
- Multiple limit switches on hanging arm used for controlling deployment and automatically starting/stopping the hanging

Did you use the vision system?
No.

What drive system?
8 wheel drive. 4" cantilevered wheels. 2 speed (w/ neutral) + power take off drive gearbox

How many motors?
4 CIM to drive. These were also used to hang and self right (which was never used)
1 CIM for kicker winch
1 FP + clutch for ball grabber

What material was used for the frame (Aluminum, steel, unobtanium)?

6061 Alum

How did they control the ball?
Pincher roller with high torque clutch on top roller.

Energy storage for kicker (elastic, pneumatic, motor driven, etc.)?
Trampoline springs. Winch driven by CIM with ratchet and pawl. Dog gear + piston release.

How did you cut your parts (water jet, LASER, mill, hand tools,etc.)?
Most plates initially cut on water jet, finished on CNC mill. CNC mill used for most everything else.

Did you hang? If so, what wenching approach did you use?
Vertical bar. Used power take off from drive for lift with ratchet+pawl to keep suspension.


The Driver Station

Did you reprogram your dashboard code?
Yes. We just added a bunch of indicators to push out sensor values for quick debugging. We used the legacy driver station console lines to print out info about and select our auto mode.

Did you use external controls beyond your joysticks?
We used analog joysticks for the driver and 100% custom controls for the operator. Everything ran through the cypress board.

Any problems in getting the USB to behave?
Sometimes the cypress board would not be recognized by the DS software and we would have to restart the computer or restart the CyProgMini (or whatever) windows service to get it to work.

Also, after a restart the cypress board would lose its configuration data. If we did not start the robot AFTER the driver station was up and running, the correct I/O configuration (which was set from the robot) would not get pushed to the board, and everything would default to a floating input. This one was particularly tricky to figure out.

Did you use any unusual controls like WiiMotes, XBox controllers, etc.?
No.

Did you feel that the Classmate was fast enough?
Not at all. Boot up times were terrible. We wasted so much time waiting for things to boot and sync.

[apalrd]

Originally Posted by Joe Ross

Our autonomous was structured into discrete VIs that had their own while loop in each one running from autonomous independent. We could then string these VIs together very much like lego programming. For example, we had a drive until ball detected, followed by a kick, followed by drive until ball detected in parallel with wait for 2 second kick retract. It was very easy to move those around as needed.

I wrote a system almost identical to this, motivated by how easily the LEGO kids I mentor can write code. I had VI's to do control on speed for distance, kick, set kick recoil distance, and a few others that I rarely used. The distance control did P control on Speed (in feet/seconds).

We have a policy of integrating sensors into our design. We try to automate the more direct robot control functions to allow the driver and operator to focus on driving, which generally means the fewest button presses necessary to perform a task. We generally don't do much based on time, but some functions have (e.g. a double-action claw in 2007 would trigger the upper claw 10ms after the lower one, and the roller on this robot would kill the roller after 5 iterations after collection and reset after 20 iterations).

[JABot67]

I guess I could post for my team, though I really don't know all the details. I'll answer what I can. Most of my answers will be quick.

Programming:

What language did they use?
LabVIEW at Kettering and MSC, C++ at Wayne State and the Championship.
That's right, we had two completely different, functional codes from different programming environments. We decided to try something different this year with such a huge programming team.

Threaded code or just poll in the teleop loop?
I have no idea what this means, though I wrote basically all of the LabVIEW code. Sorry...

Did they do something in autonomous? If so, what worked?
We had many autonomous modes. We have scored from all three zones, and have started out in all three zones in eliminations. It really helped out to have so many autonomous modes. There were major differences between the autonomous modes in C++ and in LabVIEW, but they were meant to do the same thing.

What problems did you encounter, if any, with WPILib?
No problems.

Did you download the sources and rebuild WPILib/CanJaguarLib?
No.

CAN or PWM control?
PWM control.

Did you use the Classmate for programming your robot or student/school supplied computers?
We used our own computers. Using the classmate would have been just terrible.

Robot Design:

NOTE: I was not involved with the robot build. I am a programmer, and definitely not an expert. I'll try to answer these questions based on what I know, which was gathered from working in the pits or with the practice robot.

What sensors were used?
Encoders on the left and right drive, and potentiometers on the kicker and the arm. One yaw rate gyro that was especially useful in auton. No limit switches. We had a camera that we never used.

Did you use the vision system?
No.

If so, what modifications did you have to make to the code?
N/A

What drive system? Wheels?
8 wheel tank, front and back four wheels were smaller and raised.

How many motors?
4 CIM Drive
2 FP motors for the kicker and arm
2 Window - one for the roller and the other for the shifter, to kick and to shift into arm mode.

What material was used for the frame (Aluminum, steel, unobtanium)?
Water-jetted sheet aluminum. Don't know the specs.

How did they control the ball?
Pincher, with a static bottom bar and a top roller attached to a belt that slips when a ball is being possessed, but still applies torque to the ball.

Energy storage for kicker (elastic, pneumatic, motor driven, etc.)?
Tempered garage door spring.

How did you cut your parts (water jet, LASER, mill, hand tools,etc.)?
Our frame is waterjetted.

Did you hang?
Yes.

If so, what wenching approach did you use?
We used four 200 pound gas struts, and a block and tackle. We wound up the mechanism before every match and used the stored energy to elevate the robot.

The Driver Station

Did you reprogram your dashboard code?
Yes. However, we never ended up using the new dashboard.

Did you use external controls beyond your joysticks?
No.

Any problems in getting the USB to behave?
Yes. Eventually we decided to plug our controllers directly into the Classmate, as there were enough USB ports to do so.

Did you use any unusual controls like WiiMotes, XBox controllers, etc.?
Well we have used only Logitech gamepads for the last couple years. No fancy controllers. We don't even use joysticks anymore.

Did you feel that the Classmate was fast enough?
We hated the Classmate. The one FIRST gave us decided to crash during two matches at Wayne State, disabling us for the rest of those matches. And the bootup time was way too slow.

Anything else?
We had a lot of problems this year. There were a whole lot of issues we had to face in order to come out on top. But those problem solving steps were part of what makes FIRST Robotics so fun.

Any techniques that you feel might be beneficial to others in the future?
Well we scouted a lot. Our scouting team is huge and that definitely impacted how we did at our competitions.

I'm sorry that my answers were so short, but hopefully this gives some insight into Team 67.

[Dhananjay T.]

I have most of these questions answered from team 25.

Programming:
What language did they use?
We used C/C++, with the provided WindRiver Licenses
Did they do something in autonomous? If so, what worked?
We attempted to have enough versatility to score from all zones. We had an onboard switch and up to 7 auto modes programmed to do so.
What problems did you encounter, if any, with WPILib?
We had a couple of problems while working with encoders. We got some code errors referring to the directory in WPILib. We ended up giving up on encoders, and working with other sensors.

You'll see our big problems recorded here:
http://www.chiefdelphi.com/forums/se...archid=2951632
Did you download the sources and rebuild WPILib/CanJaguarLib?
We only had the updated version of WPILib to work with. Any new version we could get, we immediately refreshed our libraries with it.
CAN or PWM control?
PWMs. We did not use Jaguars at all this year, and only worked with PWMs and Victors.
Did you use the Classmate for programming your robot or student/school supplied computers?
We used a combination of an old school laptop, and a generously donated laptop to work with our programming. We found that the older one just wouldn't let us connect a drivers station, a CRio, and a laptop simultaneously.


Robot Design:
What sensors were used?
We used two different kinds of sensors. One photogate sensor was placed in the front of our robot to sense a ball.
A limit switch was attached to a gear driven bolt for our kicker, to sense if it was winded up or not (our kicker was winded by two window motors to store energy from surgical tubing).
And a last limit switch for our hanger which we added later on in the season, to sense if our pull up was at its limit.
Did you use the vision system?
No, we felt it would be too tedious a job after the trouble we went through last year, especially with the lack of the classic bright green light
What drive system?
Tank Drive. 6 wheels. The middle ones are not lowered, but we find turning is a breeze anyway.
Wheels?
We use skyway wheels that we tread ourselves at school. This year we had to replace a couple because we ended up shredding the rubber after two regionals
How many motors?
4 CIMs for the drives
2 Window motors to wind up the kicker
1 worm-gear driven CIM motor for our hanger
2 Fisher-Price motors for our fans
2 servo pin brakes
How did they control the ball?
We used two RC Propeller blades in an air duct to pull air through the robot. We found we could suck in a ball anywhere 10 - 12 inch radius of the opening in the front. It helped with catching them in the corners.
Energy storage for kicker (elastic, pneumatic, motor driven, etc.)?
Elastic. Surgical Tubing.
How did you cut your parts (water jet, LASER, mill, hand tools,etc.)?
Some parts we cut with hand tools, drills, bandsaws etc. Mostly with stuff you find in any high school wood shop. Nothing fancy.
Did you hang?
Yes, we hung from the side bar.
If so, what wenching approach did you use?
Side bar. We had to hook onto the side bar, and pull ourselves up.


The Driver Station
Did you reprogram your dashboard code?
nope
Did you use external controls beyond your joysticks?
Nope, this year we used three of the Logitech joysticks.
Any problems in getting the USB to behave?
Except for the provided stop button annoying us in Atlanta, no problems
Did you use any unusual controls like WiiMotes, XBox controllers, etc.?
no, we deprive our drivers of that luxury
Did you feel that the Classmate was fast enough?
We found the reset times excruciatingly long during build season, but learned to adapt.

Anything techniques?
When we cut out parts for our robot, we find it easiest to print out actual size CADs of the parts, and stick them on to our material. This way our measurements are exact, as they are from full sized CADs. Gives us nice lines to follow when cutting, and saves us measuring time. I'm not sure if other teams do it as well, but it's great for us.

"Lessons learned"
We thought this year's design, and build process went fairly well, though haunted with some programming bumps in the road.

I hope this helps, please let me know if you have any questions or if I was unclear about anything.

[Alex Dinsmoor]

Well we were a division finalist, so I thought you may want our info

Programming:

What language did they use?
LabVIEW

Threaded code or just poll in the teleop loop?
I do believe it was a teleop loop. I'm not 100% sure though.

Did they do something in autonomous? If so, what worked?
In Autonomous we shot balls from all 3 zones; we had an autonomous for each zone, and a "sit" autonomous. The modes would tension the kicker, activate the magnet, and kick based on the amount of balls that were in the zone.

We found it beneficial to pre-tension the kicker to save time.

CAN or PWM control?
PWM

Did you use the Classmate for programming your robot or student/school supplied computers?
We use a combination of team and personal laptops. The team laptop contains the master code, while the student laptops contain the code in which they are working on.

Robot Design:

What sensors were used?
Encoders on the drive system (was not used), limit switches for the kicker and arm release, and a pot for the tensioner.

Did you use the vision system?
No.

What drive system? Wheels?
4 Wheel tank drive. 2 Pneumatic wheels in front, 2 omnis in back.

How many motors?
2 CIMs for drive system
1 CIM for winch
2 Window motors for kicker system
2 Fisher Price for magnet and arm release

What material was used for the frame (Aluminum, steel, unobtanium)?
C channel steel.

How did they control the ball?
Single roller on top.

Energy storage for kicker (elastic, pneumatic, motor driven, etc.)?
Variable tension surgical tubing kicker

How did you cut your parts (water jet, LASER, mill, hand tools,etc.)?
Hand tools, mill, lathe.

Did you hang?
Yes.

If so, what wenching approach did you use?
Used a compressed air strut to raise arm, winch and pulley to raise robot, arm falls once winch is engaged.

The Driver Station

Did you reprogram your dashboard code?
No.

Did you use external controls beyond your joysticks?
No.

Any problems in getting the USB to behave?
No.

Did you use any unusual controls like WiiMotes, XBox controllers, etc.?
3 Logitech Joysticks.

Did you feel that the Classmate was fast enough?
The drivers had mixed feelings about it. We did however purchase one with a larger screen (as compared to the KOP one), which may have had a faster processor and battery. The camera functionality was useful when we had one.

Anything else?
We found that designing and prototyping should always be your first steps. Also that it doesn't take professionally made parts to make a good robot.

Strategy is also your greatest aide in competition.

Any techniques that you feel might be beneficial to others in the future?
Plan, learn, improve, scout, strategize, and have fun!

[TEE]

Originally Posted by Alex Dinsmoor

If so, what wenching approach did you use?
Used a compressed air strut to raise arm, winch and pulley to raise robot, arm falls once winch is engaged.

You know Alex, it would be really cool if you could get that video right-side up =]