I am very nervous
 

I am very nervous about the regional in 2 days. We are leaving tomorrow and I have not been this nervous even for a football game. I have code for autonomy that has never been tested and I feel like that there is a 70% chance it will fail (that is what the practice matches are for). How do I combat this nervousness? I always want to make things efficient and concise for my code, but I just slapped this onto the code. That is what scares me.

Anyone on the same boat as me? Really nervous and scared? I think going to a 2nd regional this year just adds to it.

Re: I am very nervous
 

I would say accept the fact that you probably will need to fix your code. At Traverse City I had to change my code a number of times before I got the robot to hang an uber-tube. Even now I have to fix it to make it more consistent before the Week 3 competition. At least you got practice matches though if that will make you feel better. The pit or qualification matches was my time to test.

Re: I am very nervous
 

I know exactly what you are going through. Last year when I was driving in my first competition, I was shaking and very nervous. Every match I had some sort of sensation making me tremble down my legs and I could never overcome that feeling.

This year, I have only gotten that feeling once because I actually thought about me screwing up or making a mistake. The idea is not to think about the mistakes you are going to make but the best possible outcome. For us, that was a Regional Finalist medal around my neck.

The thing is, like in a football, you need to have poise and composure when doing things. I am sure that your autonom code will be perfectly fine and if not, so what. You go back and make sure that it is perfect. You shouldn't have any stress on your shoulders at all. Make sure that you get to the practice field before going to the real field to test your autonom code.

You'll do fine, just remember to think about the future goals.

Re: I am very nervous
 

We didn't even HAVE working autonomous for the Finger Lakes regional until the very end. I wouldn't sweat it. First and second week events are basically practice anyway.

Re: I am very nervous
 

I think you'll find most people are nervous, and that's perfectly fine. In fact I'd be worried if you weren't nervous. You know you're going to have to probably fix something and you're ready to do that, that's much better than going in assuming it's going to work perfectly and being flabbergasted when it takes off across the field and tries to destroy your player station. (Not that I've ever had code do that....)

Once you get in to atmosphere you'll be more excited than nervous.

Matt

Re: I am very nervous
 

Well memories of last year are coming back. We never even scored once in autonomy because one victor was on coast and the other on brake, so one side would speed up before the other. So one time we ended up turning around 180 degrees and running right up the tower. That was when everyone lost trust in me (well at least FELT like everyone)

I guess you can say I have the fear of failure. I felt that I failed to do my part last year. The worse thing is that I was not nervous at all last year. (I was more exited about skipping school than the competition)

Re: I am very nervous
 

You've clearly never seen an angry drive team that just got taken out by flying controls caused by the robot autonomously ramming the player station :). Another year I screwed up some really basic adjustments to the autonomous code and caused the robot to shoot all of its scoring balls at a wall. Another timer the robot deployed a piston 'wing' out it's side then mauled the field barrier, wrecking the piston.

That piston incident was in 2003, the entire team signed it and it's still hanging in 263s workshop :)

Embrace it, you're going to make some of your most memorable mistakes at events, and even though it may not seem like it at the time, you'll learn something new from each one, and you'll just keep improving. Also, you have the benefit of experience this time around.

Matt

Re: I am very nervous
 

Well there's your mistake right there man. You should be extremely excited about the competition and not about just missing school. It should be an exhilarating experience to see something do exactly what you designed it to do all along. If the outcome doesn't turn out that way, you work your butt off to fix it and not accept anything else.

Don't go to a FIRST competition just to miss school dude. You have to be excited about it because if not, then why are you doing it in the first place. What are you gaining from it?

If you haven't already, rethink about what FIRST is and you'll get a better understanding of why being excited about the competition is so important.

Re: I am very nervous
 

I think he no longer feels this way, I believe he simply meant last year he didn't 'get it' and now he does, and that is why he is so nervous.

Matt

Re: I am very nervous
 

Oh, no, it is different this year. Hence that is why I am nervous. I was a rookie last year, I didn't expect much. Now I got a taste of what it is, I want more.

Re: I am very nervous
 

Practice??? A great number of teams can only afford one event. This is it. Thousands of dollars and hundreds of hours all ride on a few 2 minute moments of time. No Pressure. :yikes:

Then again there is more to this program than wins and loses. There are great students inspired to change the world and gaining the skills to do it behind both winning and losing robots. Your success most likely won't affect someone elses scholarship to college. It is more fun when everything works like it was designed though.

Re: I am very nervous
 

Really? I wouldn't know....
:rolleyes:

I'm sure a lot of people are nervous, personally, I'd be kind of amused to see the kind of trouble my fellow programmers have gotten themselves in to. Is there already a thread for that? I might have to start one if there isn't...

Matt

Re: I am very nervous
 

Honestly, autonomous this year is much more difficult than last year. Plan on never capping. However, what your team need to realize, to compete this year, you need a working autonomous. Look at the finals matches from all events, they are full of robots with working autonomous. I say this, because your team needs to help you reach the goal of autonomous.

Insights I have for you from week 1. If you are running motor speed at a .1 or .2 in autonomous watch out for the batteries. The newer batteries have more power than older one's. This caused me to smash into the driver station in one match. Watch out for the coasting CIMS, if they are geared to high your autonomous will be almost impossible.

Your robot will fail epically at least once in autonomous. Try to do this on thursday, so you can learn from it.

If you have your code, feel free to send it to me mwtidd@gmail.com. I'll take a look over it, and see if there's anything you should be worried about.

If you find that the robot was poorly designed for autonomous. Just scrap the autonomous. I should have done this earlier in the comp and focused on the minibot.

Try to avoid as much blame as you can. If you get a working autonomous you will be a hero, but this is dependent on so many design factors. Its often better to let the robot sit in autonomous, and just work on getting the autonomous working on the practice field. You won't need it til saturday.

At BAE we actually organized the sharing of the practice field... we had anywhere between 2 and 4 teams sharing the space at one time. It worked really well to have 2 or 3 teams debugging their autonomous together. Its also motivating to see other working robots, and other teams having trouble. I have more fun playing in the practice area, than watching the matches :). It is the back room that the real magic happens.

Hope I helped!

Re: I am very nervous
 

This doesn't make sense to me, could you elaborate?

Matt

Re: I am very nervous
 

The drive typically get values from 1 to -1. I was running at a .15 and .25. What I found was that with the older model battery, the robot would hardly be able to move. Where as with the newer one it would cook.
The motor speeds wouldn't change but the power would. Also our cims were geared way up. So the robot didn't have the torque to move at low speeds with an older battery. It seemed the difference between the batteries was enough to give it that extra bit of torque at low speeds.

The result: you set the speeds for the older battery, and then go out with a new battery. The robot would fly into the player station.
you set the speeds for a newer battery, and go out with an older one, it wouldn't make it to target.

Re: I am very nervous
 

Interesting, has there been any data on the electrical characteristics of the new batteries? (I admit I haven't looked, been too busy trying to get my programmers to comment their Subversion entries!)

Matt

Re: I am very nervous
 

haha. I have no idea. also it seemed only to be a problem at low speeds, but it took me all comp to figure out why the speed seemed random. Again part of it was our design... a 2 cim drive direct through toughbox (1 cim per box). In the end this setup just sucks, sucks for programming, sucks for driving. We also found the setup would essentially overheat after a minute of use on the carpet, and would just quit. Hopefully other people can learn from our mistakes.

Re: I am very nervous
 

Sounds like the motors may have been near stall, and the new batteries may be a bit healthier and able to dump more current in to the motors at a given power level. Maybe we should do some battery profiling.

Matt

Re: I am very nervous
 

The first paragraph did not help much :p. I do not have the code with me, that also adds to my nervousness. And thanks for the heads up for the motors, I currently had it at around 40%. Man, our autonomy (actually software in general) usually gets scrapped until the end. We are the lowest priority apparently. Now I totally agree with you. Our sensors are literally going to be zip tied on or something. I constantly told the electronics, and CAD people what we needed from week one. It is not in any of the CADs. I can't believe everyone just expects the programmers to pull off miracles. So right now, we are like a blind man with a walking stick. It will be tough.

Keep in mind, I have been programming everyday since day one. It is just that I had been given lots of little "projects" to do. I wanted autonomy to be #1 this year, but people kept on piling on jobs to be done and it was the last thing on the other people's minds.

Re: I am very nervous
 

Traditionally programmers usually get this kind of treatment. The best plan I've seen for fixing it is to get involved in the mechanical side of things. You'll learn more skill-sets, you will be be able to personally design in and mount your sensors, and best of all, you're not 'just a programmer' anymore, so you may have better luck communicating.

Unfortunately, especially with FIRST giving out so much pre-written code (that only sort of works, not that anyone else understands that) people tend to assume the programmers job is point and click monkey.

Matt

Re: I am very nervous
 

Now, I am a very "low level" person and my mentor finds me too valuable of a programmer to be doing electronics or any hardware. I try to use the lowest to the hardware the software allows. I have just glanced over the pre-written codes, I was "appalled" by the thought of even copying the method of doing things they use. Plus, I don't like the way they do things anyway. May be that is my personality flaw, but I see it as a good thing. Might hint on the fact that I am arrogant, but shows I am independent. I have been criticized by other programmers because they think I am just making it harder on myself. I like the challenge actually and I feel guilty if I use prewritten code, feels like cheating to me. (Now it really is not cheating per se, but feels very much like it)

Re: I am very nervous
 

This. Even in FTC, teams or at least my team neglect the programming portion and focus mostly on building the robot. I also feel nervous about going to a competition because the programming is incomplete and my team is unprepared. Sometimes one has to take more control in order to get something done. Once it is off season there is much opportunity to be prepared for the next season.

Just remember, FIRST is much more than the robots.

Re: I am very nervous
 

I understand exactly where you're coming from. I hated using the code FIRST gave us, actually I still do, but I've been better about it. For me it's more of a matter of understanding, fixing code you've never really seen before and don't know the details of is extraordinarily difficult. (Ironically, I do this professionally now). I can definitely also understand wanting a challenge. Part of being a good programmer is learning the balance between working with what you have, and writing what you don't have, or don't think is worth using. For example, 263 has their own custom PID system, but we still make a good deal of use of WPILib. This balance can only be struck with some experience, and a little luck, it'll come in time.

To that end, working on the electronics and mechanical team is very very good for programmers, and even if your case I think you'd find it a lot easier to work at a higher level when you're solving more interesting problems. Instead of "they finally mounted the pot, now let me make it work" you can approach the problem as "I need to control the arm, here's what I have to work with". Plus, I'm getting really sick of the stereotype that programmers with power tools are dangerous! :) Help me change it.

Matt

Re: I am very nervous
 

My honest recommendation is to sign up to be the "Team Scapegoat". Everything is the Scapegoat's fault, so the Scapegoat always gets blamed.

Of course, it is NEVER EVER the Scapegoat's fault. So, you can rest easy knowing it was not your fault. But only as the Scapegoat.

==

Seriously: Test your code in the practice sessions, that's what they're for. At the very worst, you disable it for the entire regional - not the end of the world.

Re: I am very nervous
 

Funny, the mechanical guys always made it sound like the end of the world. :rolleyes:

Practice sessions are useful, and don't be afraid to ask other teams for help. At the same time, if you absolutely can't figure out your code problems, turn the robot back to the mechanical team and let them make all the tweaks they're inevitably going to want to make. Go take a walk and see if you can help another team with their programming problem! Believe it or not I've had many Eurekas while helping other teams, and its great networking for you and your team.

Matt

Re: I am very nervous
 

My only advice: Turn your nervousness into confidence. Be excited about the competition. This is my first year in FRC, and I am stoked for the SVR! We may not have the best robot, and we may not win, but out of what I've seen and the previous competitions I've watched, it's a fun and life-changing experience that shouldn't be ruined by nervousness. Go and have fun!

Re: I am very nervous
 

Yeah, sorry I didn't mean to psych you out. I just want you to lower your expectations and relax. You'll have a lot more fun. I don't want you to be like I was running around like an idiot.(There was one 40 min break where they had me coding and debugging, autonomous and the minibot deployment from scratch) Your team made design decisions and chose not to prioritize autonomous... that's their fault. Just be glad that in reality they can't blame you for the failure of the robot (that is unless you break the robot). Hence why I said, if you do autonomous stuff, do it on the practice field rather than the actual field. If your comfortable with it, break it out on the last day.

Remember that this year wasn't wasted, you will learn what to expect. I have a whole list of design requirements for me to implement in the off season, and I'm sure you'll have the same after comp. I'm actually planning on building my own chassis in the off season, to play around with some of the things i'd like to implement.

Have fun and make the most of comp. It's a good time if you don't take it too seriously :)

Re: I am very nervous
 

If you are experienced enough to take advantage of certain sensors, this is the easiest autonomous mode I have seen. If youre not using the sensors, then I agree with you, it is considerably harder.

Dont let yourself get down if you arent experienced enough to use the sensors, or your mechanical guys decided they werent important enough to put on the robot. Success will come as you gain more experience.

Re: I am very nervous
 

I agree, TBH, it felt as if the GDC was actually was PUSHING autonomy. They had lines and the reflective tape on the pegs (they really do stand out). Last year, it was just a circle.

Re: I am very nervous
 

Yeah they made it pretty nice this year, especially giving us those awesome photosensors.

My kids got a state machine together to run through the sequence of aligning the arm and driving up to the goal, and it was working but hard to keep perfectly aligned with the goal. Then we remembered the photosensors on the front and of the robot and were able to write a line tracking algorithm that just braked the wheel corresponding to the sensor that was tripped and we were in business. Compared to some of the autonomous challenges we've gotten before, this wasn't too bad.

Not to say it was easy, but it's certainly doable at an event.

Re: I am very nervous
 

Easier than drive forward and kick 3 balls?

Also there are elements to this years autonomous that many teams are not accounting for... ie 3 line trackers can't score without doing a dance. Even 2 line trackers makes it difficult if neither of them can do the Y.

Also many of my troubles arose from design decisions, and not the difficulty of the autonomous itself. So you may very well not see these problems.

Some regionals have many autonomous robots, others almost none. I know at BAE it was rare to see more than one ubertube hung. Lots of close calls, very few hangs.

Yes team 33 did theirs essentially with 2 encoders and a pot, but much of their success came from a well designed robot. Many of us don't have that luxury.

I just don't want david to feel like he messed up if the autonomous doesnt work. I've been doing this for 8 years, and invested boatloads of hours this year, and I didn't hang any tubes in competition. However I totally view this year as a success for me because I met my personal goals with the robot.

Re: I am very nervous
 

Consider yourself lucky that this will not happen to you, or take precautions to make sure it doesnt:


At FLR, during autonomous, all the robot did was spin around, speed up to full speed, and ram across the center line, and (going full speed) hit the opposing alliances robots, knocking them a good 2 feet away. Instant red card.


Also, due to some issues with encoders, we didn't have a working autonomous until after we were eliminated during quaterfinals. We took the robot back to the pit, and decided that we would have one. All it is is dead reckoning. But it works :D

Re: I am very nervous
 

dead reckoning is awesome this year. I also fell in love with the vex rangefinder. :)

Re: I am very nervous
 

My point was that this year they gave us lines that go straight to the scoring peg. Is this easier than driving forward to kick 3 balls? no. Is this easier than trying to score 3 balls? yes. This year, like in 07, the ultimate goal in autonomous is to score 1 tube, sure very few teams will get 2, but they are very good at what they do. Every other year i have been apart of, you needed to interact with multiple balls, or go around the field.

Why is it difficult for 2 line trackers to score if one cant do the Y? The 2 straight lines are on opposite ends of the field?

Any design decisions made that affect autonomous mode do not make the autonomous mode as a whole more difficult. Yes, it makes the challenge for your team more difficult, but you cannot consider that when making a general statement like this year autonomous is harder than last year.

In my experience, poor autonomous modes are due to not enough time given to the programmers to work. Programmers should not feel bad because of this if it doesnt work, it was completely out of their control. Also, programming in general is hard. Even though this years challenge may be easier compared to some others, programming a robot to succeed in autonomous mode is extremely difficult. I didnt get my autonomous mode completely finished until IRI last year, and then I never got the opportunity to use it.

Re: I am very nervous
 

Hey man, I know how you feel. I think we all do. Autonomous code is not supposed to be easy. Yeah some bots can do it in a second, but some teams only dream of it. You will need to change the code. Something will always go wrong. I can't remember how many times last year we had to ask for some help from the programming volunteer (Alan Anderson) and even then we still had some issues. Our main concern every year is "Does the robot perform well enough to drive and to perform the task?". If you can answer yes to that question, then you have completed the main part of it.

We are going to Boilermaker this year with brand new code all the way around. We haven't tested anything except the drive code. We will literally finish the auton code in the pit.

There is one thing you should remember though. Isn't FIRST about situations like this? You are thrown into a situation where you have to program in a PIT with tons of noise and people rushing you or you might have to drive for the first time and you are worried about goofing up. You just have to remember to ALWAYS plan for issues and then just keep cool and work them out. If you are stuck, always and I mean ALWAYS get help as soon as you need it.

Best of luck! (and sorry for the long post)

Re: I am very nervous
 

Oh, any feedback on what I have done regarding the "fork". I literally used a random number generator. I do not see it as a problem because the angles are the same both ways, just flipped. Now how has other teams done the fork? Just picked one way?

Re: I am very nervous
 

It is probably best to know which way you are going. If I was your partner, I would like to know if you guys are coming in my direction, some coordination may be necessary to make sure arms dont collide.

Also, I dont know what type of drive train you have, but we discovered that after picking the first branch of the fork, it is incredibly difficult for a 6wd to make the turn to score at the peg. You should get the straight line mode working first, and whenever you are comfortable with that, try to tackle the fork. Dont feel bad if you never end up doing the fork, it is pretty tricky

Re: I am very nervous
 

There's a fine line between nervous and excited. Try to keep your chin up and think positively and you'll have the time of your life.

Re: I am very nervous
 

This is by far the easiest auto mode I've seen since like, 2004. Drive straight a fixed distance, cap tube. You don't need a camera, or line followers, or an accurate shooter, or an accurate kicker, or an IR detector to change lanes, or traction control to even move. You just need to be able to drive straight.

Having to capture N soccer balls and shoot them into a goal M feet away, where N and M depend on your alliance was a way harder task.

(Granted the difficulty is a baseline, not a ceiling. Feel free to cap 2 or 3 ubertubes)

Re: I am very nervous
 

I think your right about the practice rounds, also I believe you will be fine 70 % is a lot better than anything below it. I believe once you see it you should be able to tweak it to usable. As far as the nervous thing goes This is for fun, and learning at the end of the day. We learn from our mistakes and improve on them. Don't be nervous, keep a level head, stay calm, and most importantly have a blast, whether you win or lose try to take away from the experience something you could tell your grand-kids some day. :)

Re: I am very nervous
 

Just a couple of thoughts:

1. I have learned over the years that nobody has higher expectations of me than I do. Although this has probably contributed to much of my "success" in life, it also means that *I'm* the one causing 90% of the stress I feel. I suspect we're similar in that regard. This is an optional situation, and completely within our own ability to change. Instantly. You can turn off the high expectations for this weekend, and turn them back on again Monday - if you choose. This is not capitulation; think of it instead as a compromise with reality and a coping skill.

2. It's always darkest right before the dawn (thanks for that one, Dad).

Re: I am very nervous
 

I think you guys reveal a good point. A difficult autonomous is often not defined by the game but by the robot design and the sensors chosen. For our team, 04 we were about 8 out of 10 at the yellow ball, 06 we shot 9 for 10 cause we used the camera, and last year we were about 2 for 3 from back field simply using an ir beam. For us these were also our simplest autonomous programs.

My comment on the Y was regarding a 3 robot autonomous. If you want the elim matches from many of the comps, in order to get 3 tubes they have to enter into a dance (or have a double capping). It's because its very difficult to cap on two pegs next to each other at the same time, there just isn't enough space.

In every year autonomous was easy, as long as you picked the correct approach and had a well designed robot. Its all relative. So I retract my initial statement... This year was much more difficult for me because the robot design.

I am just trying to let david know, not capping in autonomous is not that big of a deal, killing your robot because you though it was is. If your team loses because there was no autonomous, that's their fault because they chose not to prioritize it. For every 100 hours they get with the robot, you get 1. We finally get things working, and then they change something, assuring us it wont change anything.... and then, of course.... it does. Many of these teams with good autonomous programs had a second chassis, so for every 100 hours the mechanical team got they got 100 hours. If you are on a 100-1 team, you can only do so much.

If its not working on the practice field, it won't work on the real field. Don't make untested code changes in your pit, this is where most of the issues arise.

Re: I am very nervous
 

added emphasis mine.

Really? You're serious?

The facilities/experience/expertise/budget of a team has NOTHING to do with how well the robot is designed. I've seen rookie teams that had no clue what they were doing absolutely rock out FRC events, using kitbot chassis and pre-written code. If your robot is not well designed, the only person to blame is in the mirror.

Now implementation and execution - that's a different story.

As for the nervousness, remember that the event is a 3-day tournament. Thursday is a practice day - use that. Use the practice field to fine-tune your automode; use the playing field to show off. Perhaps Thursday morning, just drive up to a peg and that's it. By lunchtime, try to score on a bottom row. In the afternoon, reach up a bit higher. Baby steps. Everybody knows Thursday is a throwaway day; if other teams see progression and growth in your automode and teleoperated controls, they'll know your robot and team are evolving as the competition progresses and will give your team proper respect.
It sounds like your teacher understands your plight; work with him to get exclusive access to the robot and the playing field first thing Thursday. Take baby steps with it, build it up, tweak it, until it's ready to go.
Remember, your robot doesn't really have to "peak" until Saturday afternoon. Take advantage of your opportunities, let your nervousness turn into motivation and passion, and remember that when you show respect to others - regardless of team affiliation - it will be reciprocated.

Re: I am very nervous
 

I never claimed they did, I simply was commenting that well designed robot is a lot easier to program than a poorly designed one.

Re: I am very nervous
 

Here's another nervous programmer :D

I was writing autonomous mode at 9 PM on robot ship day. And shrieking when the line-following worked. And then rewriting autonomous almost completely so that we'd score as soon as we reach the tape-line T, not just overshoot it and ram the driver station as happened at our Week 0 event. And then we had to bag the robot. So autonomous never got fully tested.

Besides programming an autonomous mode that is going to have to be extensively tested and probably reworked, I am in charge of scouting, Chairman's, and am also team captain [I'm the only non-rookie student on the team]. I love my job but having code to write, hardware issues to keep an eye on, troops to marshal [ ;)], feisty limit switches to debug, matches to scout, judges to interview, and new students who are enthused but have no idea what they're doing who need to be briefed about EVERYTHING before the event.....I'm panicking just a little.

I suggest you make a list. [And probably another list, and another...] I've got loads more stuff to plan than you do [hopefully], but I find making a list of things that could go wrong and need to be fixed, things that have to be done as soon as you get to the event, things to check as the event goes on, etc is a good way to both calm your mind before the event, and be a lot more efficient during the fracas.
Also, there is no reason to be nervous about an FRC event unless it's your last year...like it is mine...enjoy it while you can. Good luck!

Lineskier, that is good to know about the .1 or .2 motor value/battery issue. I have a related question which should probably go in the programming forum but I'm going to stick it in here:
Our autonomous mode [the only place we feed a value directly to the Victors, as opposed to taking the value from joysticks] involves tank drive, going straight forward and turning [to correct if we've left the tape line]. I'm programming in C++, using Victors, and 4 CIMs.

When I am driving both sides straight forward, I can give them a value of, for example, .2 and .2 and they respond appropriately. However, when I work on the turn, and attempt to give them values of, say, .3 and -.2, a motor being given a small value such as -.2 will simply do nothing. [The other motor will happily do what it is supposed to.] I didn't have time to do extensive testing but it looks like .3 is right around the cutoff: anything less than .3 will only be correctly implemented if BOTH sides [all four motors] are given that same value.

Does anybody have any ideas as to why this is happening? At this point I'm just working around it by turning with higher values such as .4 and -.3 but I'd LOVE to go slower...

Re: I am very nervous
 

Well, I just confirmed with IFIs site that those values are acceptably high enough to instruct the Victor to do something. (Minimum throttle is 3%) To confirm I would watch the Victors during these tests and see if the LED properly indicates what you are expecting. I wouldn't be surprised if the low power enough was simply encountering heavy drive train resistance and stalling the motor. The reason it probably works with both sides is because straight driving tends to put less physical strain on the drive system.

Matt

Re: I am very nervous
 

Thank you! I am pretty sure I did watch the LEDs at some point, but I have unfortunately forgotten whatever was observed. [That makes me suspect that they weren't indicating any stalling, but I could be wrong.]

I will check this at our regional [Week 4...so long to wait..ahh!] The strain you mentioned....is this coming just from putting a heavy load on the motor? Or simply from running just one side? We tried autonomous mode on blocks many times, and still got the same problem.

Re: I am very nervous
 

Are you working with a high traction drive train like a 6wd with traction wheels in the corners? They just really really want to go straight. You have to give a bigger difference to the two sides to get them to turn.

Re: I am very nervous
 

The LEDs on the Victors simply indicate what the Victor is being commanded to do, they provide no feedback regarding stall / overcurrent.

If this was happening on blocks, it sounds like drive train binding to me. I'm not a mechanical guy, but I believe if the robot is actually moving forward, it may alleviate some tension in the drivetrain, but thats more hunch than fact. Is it consistently happening to only one side or both?

Matt

Re: I am very nervous
 

If you can get your hands on a vex ultrasonic its more reliable than the T, crazy easy to use and good to an inch or 2.
Regarding turning. Its very difficult for the robot to turn. I'm guessing your robot is geared similar to ours, and it just can't overcome the turn at low speeds. .3 sounds about right for the turn. This is actually a physical limit, because the force to turn is greater that the force to go forward. This is why I plan on working with a transmission next year. So I can have the force at the low speeds, but the speed at high.

However for this year, and your line tracker, try combining the correction and drive forward code. This will make it easier on your drive. ie, if your moving forward its easier to turn. one way to do this is to put a min Y in autonomous. so basically you are always going forward at least a bit. ( a .1 or .2 should be enough, but you'll have to play with that)

I had an interview thursday, so I missed out on the first day of comp, so I totally understand your stress. Again it sounds like the design is less conducive to a good autonomous, so maybe put less emphasis on it at first (you won't need it til saturday). Again you will get your autonomous working perfectly, the battery will change, and break everything. I'm not saying don't go for it, I'm just saying if it comes down to autonomous or minibot, go with minibot. ( I didn't and paid for it.) Also if your robot drives fairly straight, get an ultrasonic overnighted to you. You should be able to do a cap just using that.

also try talking to the mechanical team. They may be able to gear down the drive fairly quickly, which would make a huge difference for both you and the drive team. Our motors were overheating after 1 min, but then again we only used 2 cims. and if you can pick up off the floor, drive speed isn't that much of an advantage where as control is.

Re: I am very nervous
 

Yes, I am giving one side a negative value [driving it backwards]. We're using 2-wheel drive actually, with the driven wheels in the front and two free-rolling wheels in the back.
And the problem isn't that the robot isn't turning, it's that one of the motor-sides just isn't engaging at all, even on blocks.

I discovered at the last moment that in order to turn the robot, as you said there has to be a big difference....hence, driving one side backwards. A fair bit of frustration would have been eliminated had I just driven the robot myself a little bit more to see how it actually works....yay for programmers integrating with the hardware team :)

Re: I am very nervous
 

We have the same exact drive set up and had all sorts of problems. Beg them to gear it down.

also if you have the weight, ask them to chain the back 2 wheels. This should help too.

you don't on motor running cause the motors have a natural bias. Luckily friction of the playing field tends to correct this.

Re: I am very nervous
 

Yes, by 'not indicating stalling' I meant that the LEDs were indicating they were not getting a signal. I could very well be not remembering correctly though.
It consistently happened on both sides. Also, I am pretty sure that the lowest value a single motor will respond to in teleop, via joystick, is lower than the lowest value that same single motor responds to in autonomous.

Thanks again everyone for your help. Can't wait to get my paws on the robot in two weeks...

Re: I am very nervous
 

Maybe one side takes more torque before it starts turning (e.g. binding as mentioned above). If the robot is off and on blocks, is it harder to spin the wheel on one side than the other? If not, maybe the victors are not calibrated the same. Its pretty easy to calibrate them so it wouldn't hurt to try.

Re: I am very nervous
 

We don't have any weight to spare, unfortunately :( [one of our projects today is getting our 30-lbs withholding allowance under 30 lbs...]

Ahh ultrasonic sensors! The one sensor we didn't think to use...I think I will stick with the line-following though, I'm not keen on testing a new sensor at regionals. Although it sounds like it would be a great addition, we could steer to the scoring grid using my beloved light sensors, then stop at the right spot using the ultrasonic....at one point we considered using encoders as a safety net to avoid driving straight into the driver station, but scrapped that idea because I eventually realized that a LOT more encoder-ticks will go by if you are line-following and correcting than if you are just pushing the robot straight, heh.

I'm not quite understanding what you're saying about putting a min Y in auto...the only time the code stops the motors is if we've gone entirely off the line, otherwise it just switches one of the motors to run backwards and the other keeps going forward. [Not that that was particularly easy to understand on my part, heh.]

Gearing: I think our gear ratio is okay [actually, I am trusting our lead mentor on this]. We geared it to not be terribly fast, and the drivers seem happy with it, AND with all the other stuff that will break/need to be optimized, I'd rather not be swapping out gears...
However, I will talk to our mentor about this today, find out what our current gear ratio is and check that it's what we want. Thank you for the tip!

Yeah, during build season I focused a lot more on teleop stuff [including the minibot] than autonomous, mostly because autonomous is scary for a rookie programmer. I got worried after hearing about robots scoring two tubes in autonomous last weekend. All the teleop code is working nicely [except the occasional Watchdog, which I am convinced is NOT the programmer's fault because I disabled all the MotorSafety watchdogs...] and I suspect I'll spend a lot of my time at competition working on autonomous. It may go by the wayside though, if scouting seems especially pressing.

We've tested that, the wheels turn about the same on both sides. I'm not sure that this is the problem, but how do you calibrate Vics?

Thanks!

Re: I am very nervous
 

http://content.vexrobotics.com/docs/...al-9-25-06.pdf

Page 2 has the instructions.

Matt

Re: I am very nervous
 

There's a couple of things that complicate this.

By default (at least in LabVIEW), robot drive squares the input values. If you give it 0.2, robot drive outputs 0.04, which would be barely enough to turn on a victor.

Also, you need to make sure you're using the same type of speed controller in software as you are in hardware. The default victor calibration is slightly off center. When the control system knows it's a victor, it can compensate. However, if you tell the software it's a jaguar, you might be getting something outside the neutral range in one direction and inside the neutral direction in the other direction. The default framework uses robot drive with jaguars, so if nothing was changed, you can run into this issue.

Re: I am very nervous
 

Indeed, that is actually just outside the deadband. I didn't realize this was the case with the default robot drive, we skipped right over it to write our own code. This would certainly explain why low values seem to leave the Victor in a neutral state, along with your other point about the neutral point not being perfectly centered. I'll have to file that useful tidbit about the squaring away for the future.

Matt

Re: I am very nervous
 

Don't be intimidated by the 2 cap autonomous. The teams that achieved this have been working with a robot all season. Teams like 33 had it done before ship date.

I understand not wanting to add a new sensor, probably a good call. Encoders seem like they'd be a good off season project, but not on season. I personally want to try out that accelerometer they keep giving us every year.That would have saved me this year. I'm seeing more and more reasons to go 2 speed next year.(or maybe the killer bee 4speed :D )

If your drivers have been driving a lot and seen no problems, then you're probably right, the gearing is probably fine. Also we only used 2 cims rather than 4. so that may have caused problems for us.

Regarding your line tracker, rather than going forward and reverse, do forward fast, forward slow. that way your motor are working together to turn rather than stopping and turning.