Statistics on top 20 teams?

[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.

[rogerlsmith]

Back when this thread was started, I wasn't sure if you guys would consider 3357 a "top 20" team. We were picked by the #1 alliance of Teams 254 and 233 on Archimedes. With the help of these awesome teams, we won our division.

At any rate, I thought I'd share our statistics.

Programming:

• We programmed in Java
• Our code was fully threaded
• Our autonomous blindly drove and kicked, however we had camera code that aimed. Didn't use it.
• No problems that I know of with WPILib
• We did download the WPILib source, didn't compile it.
• PWM control
• Did not use the classmate for development.

Robot Design:

• We used the gyro and camera
• The vision system was set up to be used both in auton & teleop. We never used it in either case.
• In the vision system code we tweaked the PID values. It seemed to work best with the defaults.
• Drive system was direct drive, tank control.
• 4 Wheels, front 2 AM Plaction, rear 2 slippery plastic from KOP.
• 4 CIM motors, 1 direct drive on each wheel.
• Material was standard KOP C-channel
• Ball control via pinch roller made from pool noodle.
• Energy storage for kicker - pneumatically charged elastic.
• We cut parts with hand tools, and some were machined via CNC mill
• We did not hang.

The Driver Station

• We used the standard dashboard and a modified version (not programmed by us)
• We used an X-Box controller for drive, joystick for all kicking and pneumatics operations.
• USB seemed to work okay.

I did not feel the classmate was fast enough, and may have caused several communication problems on field.

[Pat Fairbank]

I'm not qualified to answer any of the detailed questions on their behalf, but I can share that 1114 used Java this year, and their programmers told me they were happy with it and would use it again.