Robot Arm C

[chalker]

Just to clarify on the 'self measure' idea, the thought is to perhaps require the teams to incorporate a tape measure or something into the lifting process, so that the event supervisor can easily read off the resulting distance without worrying about how to get a meter stick or whatever aligned properly.

[jander14indoor]

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.

I'd thought of part of that and others not. Height will be measured to height reached at end, after timing ends and must be 'stable'/stationary, so no launching rockets.

HADN'T thought of balloon on string, but easy enough to eliminate as that would be TOO easy.

Hm, must be last action of arm and part of arm. Interesting. I think we'll still be surprised how high that might go, but it would limit it because it wouldn't start action till everything else done.

As far as making bonus too large, we've thought of that, because I agree we still want to motivate the students to do the rest of the tasks. Target is a goal 10 to 50% of the rest.

Comment on the self measure idea. I like it, but I'm not sure how to validate the student's measure. That's where I need help.

Jeff Anderson
Livonia, MI

[twototwenty]

Am I right in saying that the point of self-measurement is to ensure that arms are not too tall to be measured? Because if it is, might it be easier and less complicated to, as I said before, limit the size the robot has to start at? That way, it would be pretty easy for the event supervisor to measure the height of the arm, if the arm had to be able to fit in a small box, besause it wouldn't be possible for the arm to go too high. Also, this would mean teams couldn't just have a long pole of some sort that they attach the object to and simply raise up with their arm.

[chalker7]

Am I right in saying that the point of self-measurement is to ensure that arms are not too tall to be measured? Because if it is, might it be easier and less complicated to, as I said before, limit the size the robot has to start at? That way, it would be pretty easy for the event supervisor to measure the height of the arm, if the arm had to be able to fit in a small box, besause it wouldn't be possible for the arm to go too high. Also, this would mean teams couldn't just have a long pole of some sort that they attach the object to and simply raise up with their arm.

Not necessarily, it would serve the same purpose as the self-measurement rule in Mission Possible. Sure, it would be a limiting factor, but its main goal would be to make the job of the supervisor easier.

Even with limiting the size of the imaginary box around the robot (which was the first thing we thought of when we came up with this as an option) I can think of at least one way to get the object essentially infinitely high (or at least, high enough that measurement would be impossible/definitely limited by the ceiling of the room) that hasn't been mentioned yet, so that would be something that would have to be dealt with in the rules.

[illusionist]

Am I right in saying that the point of self-measurement is to ensure that arms are not too tall to be measured? Because if it is, might it be easier and less complicated to, as I said before, limit the size the robot has to start at? That way, it would be pretty easy for the event supervisor to measure the height of the arm, if the arm had to be able to fit in a small box, besause it wouldn't be possible for the arm to go too high. Also, this would mean teams couldn't just have a long pole of some sort that they attach the object to and simply raise up with their arm.

Not necessarily, it would serve the same purpose as the self-measurement rule in Mission Possible. Sure, it would be a limiting factor, but its main goal would be to make the job of the supervisor easier.

Even with limiting the size of the imaginary box around the robot (which was the first thing we thought of when we came up with this as an option) I can think of at least one way to get the object essentially infinitely high (or at least, high enough that measurement would be impossible/definitely limited by the ceiling of the room) that hasn't been mentioned yet, so that would be something that would have to be dealt with in the rules.

Yup, I too have a very simple method that would easily fit within 30 x 30 x 30, yet reach at least 9 feet.

I don't see Mr. Anderson's issue with self-measuring. Is it that you don't trust the students to provide an accurate measurement? I'd think that it would be difficult to alter a tape measure. You can always ensure that it starts at the bottom and goes up to the height of the object. This makes the event supervisor's job a lot easier, and based on what I have in mind, it wouldn't make it too complicated for the student to build either.
I'm not sure I understand why you would need to validate it. I think that at least at regional tournaments, and maybe even states, you can do a visual inspection of the student's measuring device to make sure that the numbers are consecutive. Btw, if something like this is implemented, can you allow the measurement to be made in inches? Centimeters would be more accurate, however I've personally found it difficult to find a tape measure that measures in centimeters.

[jander14indoor]

Just the biases of my upbringing. Trust but verify. Most people are honest. Most.

I want a way to check on things to keep the rest under control. Why tempt someone to cheat by not checking. I expect this to decide state and national champions, I want EVERYONE to have confidence in the results.

Measurement will be little problem if we can inherently limit height reached.

Here's what I've got from discussion so far.
- No balloons, rockets, etc.
- Make the arm part of the height solution.
- Limit device initial size.
- Make it the LAST task, cannot start until all other scoring complete.
- Measure after run in power off state, must be stable.
- Target bonus to fraction of other tasks.
- Self measure?

What else?

Oh, and sorry for not being too specific. We're brainstorming here and I don't want to get anyone working on WRONG solutions based on this discussion,

Thanks,

Jeff Anderson
Livonia, MI

[GoldenKnight1]

I don't see Mr. Anderson's issue with self-measuring. Is it that you don't trust the students to provide an accurate measurement? I'd think that it would be difficult to alter a tape measure. You can always ensure that it starts at the bottom and goes up to the height of the object. This makes the event supervisor's job a lot easier, and based on what I have in mind, it wouldn't make it too complicated for the student to build either.
I'm not sure I understand why you would need to validate it. I think that at least at regional tournaments, and maybe even states, you can do a visual inspection of the student's measuring device to make sure that the numbers are consecutive. Btw, if something like this is implemented, can you allow the measurement to be made in inches? Centimeters would be more accurate, however I've personally found it difficult to find a tape measure that measures in centimeters.

A student could use a fabric tape measure, boil it, and then uses it since it would have shrunk thus giving them a better score. It is easy to do but also easy to check by just taking a trusted ruler and placing it up against the student supplied device. It is better to do this than to have one team get away with it and beat another team that is following the rules.

[illusionist]

Just for discussion:

When you say that it must be 'part of the arm', does that imply that we can have a separate mechanism that is position somewhere on the arm, or must the arm's end effector lift the bonus object? Having teams use the arm's end effector would be a good way to limit height.

[harryk]

Just for discussion:

When you say that it must be 'part of the arm', does that imply that we can have a separate mechanism that is position somewhere on the arm, or must the arm's end effector lift the bonus object? Having teams use the arm's end effector would be a good way to limit height.

There's still a flaw in that, how do you determine whether or not it is part of the arm? And I'd still be able to get it pretty high by attaching a mechanism to the arm, technically it would be an end effector

[jander14indoor]

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

I did a quick search, found lasers accurate to fractions of an inch, that would work great for me. Problem, costs of all I found were north of $100, anyone aware of any cheaper alternatives?

Just for discussion:

When you say that it must be 'part of the arm', does that imply that we can have a separate mechanism that is position somewhere on the arm, or must the arm's end effector lift the bonus object? Having teams use the arm's end effector would be a good way to limit height.

Don't want to specify the answer, prefer to specify the problem. What I'm thinking is that the arm (or arms) that move the objects must somehow be part of what raises the ping pong ball. Goal is to not allow the ball to be raised till after arm is otherwise done. Might be best to just say that.

thanks,

Jeff Anderson
Livonia, MI