Statistics on top 20 teams?

[kstl99]

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.

I am a mentor on Oz-Ram, 1922. At our first meetings after kickoff we decided our priorities would be speed, agility, and a good kicker. We used mecanum wheels and a wide orientation. We ended up being quick and very maneuverable. We were very good at getting to balls and clearing them into the front zone when we were in the middle or rear and could score well also. We could easily go over the bumps with a little momentum and go through the tunnel sideways. We were #1 seed at BAE, won in Boston and made the semi-finals in the Newton division. Sorry if I am bragging but my point is that with our strategy the mecanums were very much an asset.

[CoachPoore]

We were 5th seed on Archimedes...

Programming:
What language did they use?
C++

Threaded code or just poll in the teleop loop?
We divided the code into a number of different robot subsystems, each of which was called from {Autonomous,Teleop}Periodic. As much code as possible was shared between teleop and autonomous.

Did they do something in autonomous? If so, what worked?
We implemented an autonomous virtual machine which gave us the ability to quickly code many different autonomous modes for all 3 zones, and add more as the season progressed. We had around 20 programs ranging from "kick 5 balls" to "kick 3 and head for the center of the far zone" to "kick 2 balls then block the tunnel". Of the 20 we regularly ran about 5. I don't think we ever started in the near zone in any of our matches so far so there are several programs we never tried at a competition. We also had the ability to program a whole number of seconds delay before the autonomous program ran, which proved to be useful on a couple of occasions to make sure we were not in the way of our alliance partners. We used the 5 ball autonomous a lot at GSR and in NC. In Atlanta with a very capable field of robots we did not need it, but were still crossing the bump in autonomous when necessary for match strategy.

What problems did you encounter, if any, with WPILib?
None

Did you download the sources and rebuild WPILib/CanJaguarLib?
Downloaded the source for reference, did not rebuild WPILib. Did rebuild the CAN code so that it did not mind what firmware version number came back from the Jaguars as all of our Jags were returning the same (very) wrong number. Kept up to date with new releases.

CAN or PWM control?
CAN. No problems once we upgraded to the v89 firmware. We had 7 Jaguars on the CANbus.

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

Robot Design:
What sensors were used?
Encoders, limit switches, current sensing via the Jaguars, gyro.
Did you use the vision system?
We wrote aiming code but decided that ball pickup was harder than aiming the robot so we used the camera solely for video feedback to the drivers.
If so, what modifications did you have to make to the code?
What drive system?
4 CIMs, AndyMark 2 speed transmissions, pneumatic shift.
Wheels?
9" pneumatic at the front, dual omnis at the back.
How many motors?
9 motors
What material was used for the frame (Aluminum, steel, unobtanium)?
Alumimum
How did they control the ball?
"Active shepherding" units to guide the ball into a suction cup.
Energy storage for kicker (elastic, pneumatic, motor driven, etc.)?
Compression springs.
How did you cut your parts (water jet, LASER, mill, hand tools,etc.)?
Some parts were made on a mill and lathe. Most of the robot was made using hand and power tools.
Did you hang?
No
If so, what wenching approach did you use?

The Driver Station
Did you reprogram your dashboard code?
Yes
Did you use external controls beyond your joysticks?
No
Any problems in getting the USB to behave?
Not once we replaced the KoP hub
Did you use any unusual controls like WiiMotes, XBox controllers, etc.?
Gamepad for kicker control
Did you feel that the Classmate was fast enough?
Yes, once we replaced the default dashboard code

Anything else?
Any techniques that you feel might be beneficial to others in the future?

[TEE]

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.

Which team and which year?

[NickE]

Originally Posted by TEE

Which team and which year?

1625 2010

[TEE]

Oh rly? How'd I miss that o_o ?

[RobertG]

Programming:

• Language: C++
• Threaded code or just poll in the teleop loop: We had most of our code in a loop with the exception of the PID controllers
• Did they do something in autonomous?: We had nine autonomous modes. Our autonomous code essentially would kick everything in its path until it reached a certain distance. We also could drive over the bump and wait a few seconds for the air tanks to pressurize. At the championship we usually kicked three from the far zone and went over the bump.
• What problems did you encounter, if any, with WPILib?: We encountered a few problems with the vision code.
• Did you download the sources and rebuild WPILib/CanJaguarLib?: We made a few modifications to WPILib.
• CAN or PWM control?: CAN. This allowed us to sense the increase in current from the pincher motor when we had the ball.
• Did you use the Classmate for programming your robot or student/school supplied computers?: Team supplied computers.

Robot Design:

• What sensors were used?: Encoders on the kicker gearbox and drivetrain, VEX Limit Switches to calibrate the kicker gearbox encoder, and current sensors in the CAN Jaguars
• Did you use the vision system?: Yes. We mounted the camera below the bumpers so our drivers and coach could see the balls.
• What drive system?: 6 wheel tank
• Wheels?: 7 inch tractrion
• How many motors?: 4 cims for the drive train, 1 cim for the pincher, 2 Fisher Prices for the kicker
• What material was used for the frame (Aluminum, steel, unobtanium)?: Aluminum
• How did they control the ball?: A pincher with rubber splicing tape
• Energy storage for kicker (elastic, pneumatic, motor driven, etc.)?: Rubber sheeting
• Did you hang?: No

The Driver Station

• Did you reprogram your dashboard code?: We used a custom dashboard for a fast (30fps) video feed. I believe we found it on Chief Delphi.
• Did you use external controls beyond your joysticks?: No
• Any problems in getting the USB to behave?: No, except once during the finals on Newton when it refused to recognize the stop button.
• Did you use any unusual controls like WiiMotes, XBox controllers, etc.?: No, although we did use a heads up display to signal ball possesion and whether our kicker was ready to fire.
• Did you feel that the Classmate was fast enough?: I did not notice any delays during robot operation.

Any techniques that you feel might be beneficial to others in the future?: Secure the CAN bus cables. During one match a stray wire or hose depressed a tap allowing the cable to come out. Also, during the Newton finals we had watchdog errors most likely because a CAN bus cable (still secured by its tab) had come out slightly.

I'm just looking to try to collect a "lessons learned" from this year's competition. I'll collate the results and post them back to CD.

I am not sure what lessons we could learn from just this data. I suggest collecting data from as many teams as possible so you can attempt to control for variables or at least have results to compare the top 20 teams with.

[taichichuan]

Well, I'm looking for trends. What do many of these teams have in common? Essentially, if there are common characteristics for these top teams, then this is something that others might like to know to improve for future competitions.

For instance, I was not aware of the whole mechanum wheel thing. Seeing that only 1-2 teams have ever made it to the finals with mechanum wheels should give a robot design team some cause for pause. It's not that a superior design won't prevail, but perhaps starting out with mechanum may not be a good idea when facing a challenge like Breakaway.

We've been getting some great responses so far. I'm on the road at the moment. So, when I get back home, I'll start collating the data and get some preliminary information back to the group. Thanks and keep the data coming!

Mike

[sgreco]

Here are the drivetrain trends. I see a trend for skid steers. I left blank information that I either didn't know or couldn't find.

2010
67 – 8 WD long
177 – 8 WD long (articulated is sets of two, front and back)
294 - 6WD long

2009
67 - 6WD wide
111 - 4 wheel crab (non-coaxial), wide
971 - 6WD wide

2008
1114 - 6WD long
217 - 6WD long
148 - three-wheeled crab (coaxial), nonagon-shaped robot

2007
177 - 6WD long
987 - 6WD long
190 - 6WD long

2006
217 - 6WD long
522 - Treads, long
296 - 2WD long, Omnis in front

2005
67 - three-wheeled crab (non-coaxial). Flop bot.
330 - 6WD long
503 – 4WD long, omniwheels in rear


2004
71 - 4WD long
494 - 4WD long
435 - 2WD long, with casters in front

2003
111 - Four-wheeled non-coaxial crab (with dropdown skid for turning)
469 – 4WD Long
65 - 4WD Wide

2002
71 - 4WD flop bot with casters in front
173 - 4WD long
66 – 4WD long

2001
71 - ?
294 - ?
125 - ?
365 - ?
279 - ?

2000
255 - ?
232 - ?
25 - ?

1999
176 - 4WD long w/ Omnis in front
1 - tank treads, long
48 – 4WD, long

1998
45 – 4WD long with Omnis in front.

1997
71 - ?

1996
73 - ?

1995
100 - ?

1994
144 - ?

1993
148 - ?

1992
126 - ?

(I just compiled the information from this thread http://www.chiefdelphi.com/forums/sh...ad.php?t=77412)

[akeisic]

2001
71 - ?
294 - 4WD-long. And still functioning today! :-D
125 - ?
365 - ?
279 - ?

[akeisic]

Programming:
What language did they use?
C++

Did they do something in autonomous? If so, what worked?
1: Start far, kick 3 (no bounce)
2: Start far, kick 3 (with bounce)
3: Start far, kick 3 (no bounce), go over bump
4: Start far, kick 3 (with bounce), go over bump
5: Start mid, kick 2
6: Start mid, kick 2, back up, turn toward center
7: Start near, kick 1
8: Start near, plow into net
9: Start near, kick 1, back up, pause 5 sec, move forward, kick anything in path

In all modes we used current sensing to detect the ball and set the maximum distance. This was enormously helpful as we could easily adjust the starting position of the robot and distance from the ball without having to worry. We used mode 1 and 3 the most.

CAN or PWM control?
CAN. We had some trouble with the tan jaguars losing their identity, but fixed those with a patch. It definitely cleans up wiring, but you MUST ensure the wires are secure. If you lose 1, you lose them all! This is why we didn't move in the 2nd match of Newton finals. We're talking about using PWM for drive and CAN for auxiliary for next year.

Did you use the Classmate for programming your robot or student/school supplied computers?
The team recently purchased a dedicated programming laptop.

Robot Design:
What sensors were used?
Jaguar current sensing for the intake roller, encoders on left and right drive train, encoder for kicker winch system, 2 limit switches for kicker zero and kicker max.

Did you use the vision system?
Yes! - but not the way you would think. We mounted our camera below our bumper so we could see behind those pesky bumps. It was especially helpful in the far end of the field. It also helped us see directly below the drivers station.

What drive system?
6WD with a 0.100" lowered center wheel. The center wheel was driven directly and the front/back by a single loop of chain.

Wheels?
7" traction wheels - Thank you Northrop Grumman!

How many motors?
Drive: 4 CIMs
Intake: 1 CIM
Kicker winch: 2 FP
Pneumatics: 2 for 2 speed transmission, 1 for ratchet release

What material was used for the frame (Aluminum, steel, unobtanium)?
Welded aluminum. Mostly 1/16" wall, but 1/8" where we needed it.

How did they control the ball?
Pincher design with friction clutch and center back stop. We pulled balls away from many teams - including 1114 and 1902.

Energy storage for kicker (elastic, pneumatic, motor driven, etc.)?
flat elastic pulled back by winch and released by ratchet.

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

Did you hang?
No.

The Driver Station
Did you reprogram your dashboard code?
Not to my knowledge.

Did you use external controls beyond your joysticks?
We had a heads up LED display, but no external controls

Anything else?
Any techniques that you feel might be beneficial to others in the future?
Ensure you have a battery load tester. While we tested our batteries in the lab (plotting the full drain of the battery), having a battery load tester in the pits is crucial. We disposed of 3 batteries after the championship because they were beyond their life! We couldn't climb over the bump during the finals in LA because of bad batteries.

[jspatz1]

1986: Curie #3 seed and finalist

Programming:
What language did they use?
Labview
Threaded code or just poll in the teleop loop?
huh?
Did they do something in autonomous? If so, what worked?
We could score all balls in any single zone from any position. Same basic program for each zone, just changed aim angle (robot orientation), kick strength, and number of kicks for each position. Our swerve drive allowed us to advance to each ball and maintain proper aim angle. Good success rate. We scored 3 several times.
What problems did you encounter, if any, with WPILib?
None
CAN or PWM control?
PWM
Did you use the Classmate for programming your robot or student/school supplied computers?
Other computers
Robot Design:
What sensors were used?
Potentiometer on kicker pivot to measure drawback
Magnetic encoder (KOP) on swerve steering to give absolute wheel orientation
Horizontal gyro to measure robot orientation
Verticle gyro to measure tilt on bumps and provide input to bump auto-pilot
Magnetic switch on kicker cylinder to sense extend position
Microswitches on ball magnet roller to signal ball possession
Did you use the vision system?
Tried to for autonomous. Gave up on it...too slow. We had momentary vision aiming that the driver could use on demand.
If so, what modifications did you have to make to the code?
I don't know that.
What drive system?
4 wheel crab/swerve, CIM motors within the modules. Wide format.
Wheels?
6" AM Plactions.
How many motors?
4 CIMS - drive, 1 CIM - steering, 1 FP w/ modified gearbox - ball magnet roller
What material was used for the frame (Aluminum, steel, unobtanium)?
3" aluminum C-channel, .875 dia x .055 wall aluminum tubing
How did they control the ball?
Foam pool noodle ball magnet roller, spin the ball against the carpet. Worked well.
Energy storage for kicker (elastic, pneumatic, motor driven, etc.)?
Pneumatic retract with elastic kick. We could release the kicker at any point of drawback which provided infinitely variable kick strength. This proved to be very advantagous.
How did you cut your parts (water jet, LASER, mill, hand tools,etc.)?
Water jet, mill, bandsaw
Did you hang?
No. We chose to keep scoring goals.

The Driver Station
Did you reprogram your dashboard code?
Yes
Did you use external controls beyond your joysticks?
Yes, we duplicated several pushbottun functions that were also on the joystick so either driver could do them. Kicker strength throttle pot. was external from the joystick.
Any problems in getting the USB to behave?
Yes, often. I/O board and sometimes joystick would loose connection.
Did you use any unusual controls like WiiMotes, XBox controllers, etc.?
No. Joystick, pushbuttons, potentiometer. We did have an audible buzzer that signaled ball possession.
Did you feel that the Classmate was fast enough?
No.
Anything else?
Any techniques that you feel might be beneficial to others in the future?
Facing our goals at all times with a crab drive was a big advantage for us.

[taichichuan]

Hi Gang!

Preface

OK, thanks to all those folks who responded. I started this thread to see if there were any common characteristics of the teams that experienced a modicum of success in this year's competition. By asking a series of questions (next year I'll try SurveyMonkey instead), I tried to gather some info to determine what might give a team some guidance as to what technologies they should try to come up to speed on. Obviously, there was no control group or attempt to be a rigorous scientific survey. The sample size was way too small for that to be sure. This is because many teams just stop paying attention after the build season comes to a close.

In this effort, I was just trying to get a feel for where folks found success that we all could learn from.

Results

I've collated the responses and here they are:

The language in use was pretty evenly split between C/C++ and Labview with 58% using C/C++. None of the respondents used Java.

Only a couple of teams knew what threads were. The Labview code uses threads internally. But, only 20% of the respondents were using threaded techniques consciously. Given the move to multi-core processors in the embedded industry, knowing what a thread is and how to use it is pretty important. As mentors, we should probably do something about this knowledge gap...

All of the respondents operated in autonomous mode and the majority scored in this mode. Many had multiple "plays" that they could run from different field positions. The majority used closed loop encoders to determine position from a known starting point.

Most of the respondents had little or no trouble with WPILib functionality. However, a couple of teams did rebuild the library and fix minor nits. Nonetheless, many commented on the poor documentation and lack of examples of the WPILib services.

66% of the teams used PWM for motor controls. Of those that used CAN, the biggest concern was losing a CAN cable lost the entire CAN bus from that point forward in the chain. However, the current sensor capability on the CAN-enabled Jaguars was used by several teams for ball detection.

No one used the ClassMate for development. In general, the comments indicated that the ClassMate had issues with lengthy reboot times, USB connectivity problems and an inability to keep up with the data that was being thrown at it. Most development was done on personal laptops or school-provided PCs.

As for sensors, the general trends were for the use of closed-loop control of robot position and speed. Wheel encoders were used by most teams (70%). Only 25% of the respondents used gyros. None reported use of accelerometers. There were limit switches used for the hang feature and broken-beam sensors for detecting the ball. No, IR or SONAR ranging was used.

The respondents were split evenly on the use of the vision subsystem. Of the half that used it, it was not used for continuous video. In fact, it was only used sporadically to confirm target was aligned or to see balls when the robot was out of direct sight of the driver. The half that did not use the vision system sited it as being slow and having too many bugs for reliable use. 1 respondent did try to fix some of the issues.

The favored drive systems seemed to be split between 6WD (33%) and 4WD (33%). There were a couple of 8WD and 1 crab/swerve drive robot.

Remarkably, many teams mixed wheel types on their robot. Plaction and Omni were used in conjunction with each other and with pneumatic. Only one respondent used mechanum. One used slick and one use skyway wheels.

66% of the teams used 4 CIM motors to drive the robot. Window motors and FP motors were used for kickers, vacuums, and the roller/pincher assemblies. One team actually had *9* motors on their bot.

The most common frame material was definitely aluminum with only 8% saying that they used a steel frame. Likely due to its scarcity, unobtanium was not used by any team . Issues of welding aluminum meant that teams using aluminum had to have access to experienced aluminum fab facilities or aluminum welders.

66% of the respondents had access to sophisticated water jet or CNC milling equipment to cut their parts. The rest used a hand mill/lathe or hand tools. All of the teams used small hand tools such as band saws etc for smaller parts.

75% of respondents used some sort of ball roller or pincher to control the ball. 25% used a vacuum of some sort with one using a ducted-fan assembly from RC airplanes. I didn't think about that possibility....

50% used elastic tubing or sheets for their kicker. 30% used springs of some sort and the rest used a pneumatic kicking assembly.

50% of the respondents said that their robot hung during competition. Of those, 33% used worm gear or screw drive and the rest used a winch of some sort.

60% reworked the dashboard code in some way. One completely replaced it commenting on the lack of speed of the default code as an issue. Another rewrote the code to be able to collect performance data for pit analysis.

60% did not use any external controls beyond the joystick. Of those that did use external controls, problems with Windows drivers, hot plug issues and Cypress board going off line problems were commonly reported. Joysticks and Logitech gamepads were the most common control in use. What? No VI gloves? A couple of teams added additional instrumentation to their robots in the form of bright LEDs to inform the drivers that the target was aligned, kicker was in position or a ball was in possession.

As for the ClassMate, then general feeling comments were:
1) It took too long to boot. This made it difficult to prepare for the match, or recover in the case that the Cypress unit failed or the FMS failed.
2) The Windows O/S crashed during matches.
3) The USB drivers for the Cypress board were unreliable. Plugging and unplugging wouldn't fix connectivity issues with the Cypress. So much for plug and play.
4) The KOP USB hub was buggy and many teams replaced it.

Thoughts

Naturally, some of these results may be simple correlation and not have a direct cause/effect relationship. Still it was interesting to look at.

If I had to try to draw any conclusions, I'd say that teams should spend some time coming to grips with closed-loop control systems (e.g., for motor control) and aluminum metal working techniques. Many, but not all, of the respondents had access to sophisticated metal cutting techniques. But, hand tools were the rule of the day in the final assembly. This means that we, as mentors, really need to take the time to show the students how best to use these tools safely and effectively.

As to whether you should spend your time learning C++ or Labview, 60% were using C/C++ and the rest were Labview. None of the respondents were using Java. Considering all of the noise made by the WPI folks over the introduction of a Java version of the WPILib, I'm somewhat surprised. But, maybe it's too early to make that judgment at this point. I'll leave you to draw your own conclusions on the language.

The ClassMate was pretty much reviled. It was too slow, required *forever* to boot and suffered from significant USB driver issues. Maybe it was a Windows thing trying to get too much code on a slow processor. But, the netbook market is pretty vibrant and lots of folks are using them. So, I,m not sure if the speed of the ClassMate, the amount of memory, the O/S, or the FLASH storage was the problem. But, clearly, there's a problem.

The other clear output of this exercise is that FIRST teams are very resourceful and imaginative. I saw some very sophisticated drive mechanisms at the competitions -- many of which actually worked . Whether you go for the complex or the simple, there's just nothing like seeing your team's robot go rolling across the field under your control. And, the teamwork that has to happen to deal with the unexpected is nothing short of inspiring.

Thanks and good luck in the future,

Mike

[Chris is me]

Interesting results.

For what it's worth, though 2791 isn't a top 20 team, we programmed in Java this year and had no code bugs throughout competition. We even had a consistent (albeit extremely simple) autonomous. I think the Top 20 teams just have mentors and student teams already trained in the old languages.

Do consider though how much of that is simple correlation rather than causation. Some stuff (like sensor-driven autonomous modes being more successful) would probably be correct though.

[taichichuan]

Good point on causality vs correlation. I added a comment to the post to that effect.

As for Java, I suspect that few wanted to be the guinea pigs on Java in the first year out. I know a few teams who did try it successfully. I'll add your team to that list.

In the embedded programming space, many of us look at Java as a great way to generate a GUI, but not as something targeting real-time controls due to memory issues, garbage collection delays, inability to access physical devices directly (e.g., no pointers) etc. That being said, the real-time Java folks have been able to get millisecond accuracy for a significant number of applications. That's likely more than fast enough for anything we're doing with FIRST.

Thanks,

Mike

[Jamie Kalb]

Originally Posted by Chris is me

For what it's worth, though 2791 isn't a top 20 team, we programmed in Java this year and had no code bugs throughout competition. We even had a consistent (albeit extremely simple) autonomous.

Same story here on 3129. We had a rookie programmer who had taken a short class in Java before the season, and wanted to continue working with it. He picked it up fast.