Robot Arm C

[mrsteven]

Hoping that some folks are still following SciOly over the summer. I'd like to leverage the expertise/ideas that exists within the SciOly community.

We're adding an open ended scoring element to the event for next year (I hate technology events where perfect scores are possible!) to minimize need for tiebreakers. Since its still draft, I'm not going to get to specific since it might change, but...

Here's the concept. Pick up one of the objects and raise it as high as you can while executing the rest of the tasks. The higher you go, the more points. Scaled to be significant, but not to swamp the rest of the tasks. My concern is the students will surprise us (as they routinely do) and we'll be seeing heights in the multi story range at nationals.

I'm not concerned with measuring height accurately till you get above reasonable step ladder range. Then I need to start looking at indirect methods. Now I'm not arrogant enough to think I'm the one with the best ideas on how to measure, so...

Question, how would YOU measure the height accurately. In detail. Low to mid range. Really crazy high.
Alternatively, can I make the students responsible for displaying height reached? If so, how do I validate what they report?

Thanks,

Jeff Anderson
Livonia, MI

I live on the forums... I sleep in the gallery section next to the helicopters button on Wednesdays
In terms of the height element its an interesting proposal but I would be weary of it. It would cause issues with measurement (like those you have expressed) and would favor teams with more money. Before I resurface that old argument this one is a little more founded. Traditionally robotics is expensive. It just is. You can certainly get around it and make ~80 robots that work well, I know this. I've done it. But adding a height element you have a whole new issue. The torque in servos (fairly standard thing for robot arm) would need to be very high to lift the arm to such a height, ranging close to the ~50 a pop servos or more. Material costs for the metal between motors is minimal, unless you add height so to keep the servo cost down, you need to buy more specialty materials that are strong and light weight. This would also require you to use higher angle servos (180+) than the 90 most use. Yes, you can get it high with 90 degrees, but to be competitive you'd need to be basically straight up. And I'd hate to blow my $300 SO budget for all events on $50 servos eating up my funding basically crippling me for any other event

Not a fan of the idea but I'm interested with the concept. I agree with you that some people will make it ridiculously tall, so perhaps put a limit on the max height where scoring will count? (like was done with towers last year at 70 cm) Limit it to what a person can reach with a measuring tape on a small step ladder. measurement could be a problem since you're idea has measurement happening while the robot is actively moving up and down. Perhaps use a meter stick and have a supervisor actively look horizontal at the claw and place a hand where it meets the highest point in the motion, lather, rinse repeat for the remainder of the run?

Better idea. have the student have 1 chance to do it rather than over the course of the run. have the student tell the supervisor before they attempt their 'high' point so they can be ready to measure once with someone holding a meter stick on one side of the arm and the supervisor measuring by looking horizontal at the actuator to the meter stick during the -lets say 10 second period- time called for the 'high point task'. Or even when the student calls the highest point, stop the run for a moment to measure, then resume time.

Oohhh my favorite! Only allow the bonus to those who have time left!!! Instead of measuring during the run, measure AFTER. If the participant has time to spare at the end of the 2 minute run time, use the remainder to get the the highest point possible and measure before time is up. So only available bonus for those able to make an arm to complete the course early. Obviously if the team chooses to go for this bonus without completing the run, its an option but wouldnt be able to go back with spare time and move more things.

That one is my favorite. Easy to measure. Places emphasis on time that this year didnt. And allows teams to go for it even if they werent able to move everything. Perhaps make it a number of points depending on height and adds to the score?

I wouldnt have students self report, too bias and naturally people will lie. I can't say I've ever turned in a real flight log for helicopters at any point over the last 2 years that reflect the actual top scores it can achieve. People will naturally up their estimates if in question. So for 'crazy high' I'd say make a cap so that you don't have to get a 3 story latter.
Or do some math... stand 100 ft away from the claw, site it, get the angle, use geometry!

Actually after that last idea I might enjoy that bonus... mhm. Interesting.

[Paradox21]

Hmm, there are laser rangefinders. They can measure hundreds of meters with millimeters of error. I think you can get some for pretty cheap.

[iwonder]

Hoping that some folks are still following SciOly over the summer. I'd like to leverage the expertise/ideas that exists within the SciOly community.

We're adding an open ended scoring element to the event for next year (I hate technology events where perfect scores are possible!) to minimize need for tiebreakers. Since its still draft, I'm not going to get to specific since it might change, but...

Here's the concept. Pick up one of the objects and raise it as high as you can while executing the rest of the tasks. The higher you go, the more points. Scaled to be significant, but not to swamp the rest of the tasks. My concern is the students will surprise us (as they routinely do) and we'll be seeing heights in the multi story range at nationals.

I'm not concerned with measuring height accurately till you get above reasonable step ladder range. Then I need to start looking at indirect methods. Now I'm not arrogant enough to think I'm the one with the best ideas on how to measure, so...

Question, how would YOU measure the height accurately. In detail. Low to mid range. Really crazy high.
Alternatively, can I make the students responsible for displaying height reached? If so, how do I validate what they report?

Thanks,

Jeff Anderson
Livonia, MI

I second mrsteven on this one, just have the team hold the object as high as possible at te end of their run(but it would have to be there before the time was up) and meausre at that point. It saves trying to find a place to put te object while the arm completes the second task, and gives the ES more time for measurement. As to the extreme height, I don't really see it as an issue I can't imagine anyone getting outside of 6 feet.

Regardless, it should be possible to use a measuring tape like those used for gravity vehicle and have a team member hold the free end of the tape at the object(if they knock it out, personally, I'd let it go and just have them hold it at the end effector) while the es looks at where the tape is hitting the ground(the tape would be unspooled the entire time). One thing you would have to watch out for is the thickness of whatever base the robot arm has(mines 3/4 inch ply) and the components on the base that would disturb the measurement on some arms, so maybe have the teams hold the object outside of the robot arm square during the measurement so the tape is always hitting the ground. And if the es is carefull and doesn't touch the tape, it should always hang right below the object.

Alternativly, the height could be limited to one meter(which seems incredibly short, honestly) and the es would simply hold the meter stick next to the object while the other end rests on the ground and take a reading... Not as fun, but effective.

So I could imagine a line reading,
"Max Height Bonus: At the end of the run, but before time has expired, the team has the option of moving an object to the heighest point attainable by their arm, while remaining outside of the robot square. At this point, the team will call time[could be tiebreaker ] and the Event Supervisor will use an extended tape measure, or similarly effective method, to measure the distance between the object and the ground directly beneath it."

May be a little long winded... But I hope it helps.

[twototwenty]

I am having a hard time imagining this new bonus (although I really, really support the whole no-perfect-score thing), but I think a good idea might be , instead of limiting the maximum of the bonus (which takes away the no-perfect-score) you could limit the starting size of the robot say, to a 30 by 30 by 30 cm box, which makes it much harder to get ridiculously high arms. You might want to even make the size limit smaller. Also, you could make the object it has to hold heavy, so the arm beneath it has to be stirdy, and thus bigger.

[harryk]

I really like the idea of a maximum height score, though it has too many flaws to work. Right now I can think of several easy ways to get an object several stories high. It's too easy, and there'd be no easy way to accurately measure the height. Perhaps use the same concept, but horizontally rather than vertically. Still pretty easy to accomplish, but not so easy to over-do, and much easier to measure.

Though, I hope everyone realizes that in these scenarios, most people will probably have a separate mechanism(as I am imaging) from the arm itself.

[mrsteven]

well I think horizontally is actually a bit easier to have done, but that requires a massive amount of torque to have done, meaning uber pricy seros/motors...

Im still a fan of the 'at the end of the run, get the arm as high as possible and use that as the height bonus'
- simple to measure since its the end and thus no more moving around
- Still makes the challenge of height (with a specific mention in the rules that the arm used to move the objects is the height measured, not some pole someone attached just for the bonus or other oddity)
- Allows the time aspect to be put in, like this year it was not

[harryk]

well I think horizontally is actually a bit easier to have done, but that requires a massive amount of torque to have done, meaning uber pricy seros/motors...

Maybe you missed my last statement

Though, I hope everyone realizes that in these scenarios, most people will probably have a separate mechanism(as I am imaging) from the arm itself.

Theres no need to have servos or motors at all, though making a very tall tower is much easier than a very long horozontal stick

[illusionist]

Thinking of both the issue with "attached to the robot" this year, and the balloon bonus in Mission Possible a couple years ago, I can imagine a team constructing some sort of launching mechanism that would shoot a part of the robot holding the object straight up, but still be attached by string (kind of like a rocket). Sure there could be ways to go around this, but I think something like this will be the result. Of course, I could be totally wrong and Mr. Anderson might have already thought of this.

One way to get around such an issue is to require that the object be held above 'x' centimeters for a certain period of time in order to be eligible for the bonus.

[blazer]

This bonus also reminded me of the Mission Bonus. That balloon bonus was so large the national medaling teams did not even have to worry about completing all the tasks in order to secure a medal. To the maximum distance others have suggested: this addition is impossible because it defeats the entire purpose of the bonus - to make perfect scores impossible. I am of the opinion that the bonus should be something that only the very good teams even need to worry about, like the tiebreakers last season; the tiebreakers that only decided the ranking at very competitive state tournaments like Ohio and Michigan and nationals.

[mrsteven]

I agree, something really difficult that isn't going to even be attempted by the vast majority of the teams, like with the chinook thing in helicopters.
It really helped those who were able to make it, but wasnt attempted by most people, and in some states no one had a successful one.

Really make people crank out something new and original that requires a good deal of time to figure out