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Re: Robot Arm C

Posted: October 3rd, 2015, 11:09 am
by windu34
I'm getting ready to start the programming part of my arm. I am using the master-slave system with Hi-Tec servos and Arduino Mega 2560. I have been testing the arm with the basic servo knob code from the Arduino site, but it is not sufficient by itself to efficiently control the arm (results in jerking due to quick acceleration, etc) . Does anybody know where to learn about PID control or inform me on how it work? What else could I use to improve my servo response?

Re: Robot Arm C

Posted: October 7th, 2015, 2:06 pm
by futaba
Hello,

Have you had a chance to revise your PDF of the board set up? Also, does anyone know when the official one will be posted? we really need one to ensure that the boards are being set up correctly at each competition.

Thanks,

Re: Robot Arm C

Posted: October 7th, 2015, 2:40 pm
by bearasauras
Are you hosting an invitational tournament? If so, please let me know and I can get it to you before it's posted.

Re: Robot Arm C

Posted: October 8th, 2015, 6:42 am
by futaba
Hello,


Yes, I am helping and will be in charge of this event at several of the invitationals. Please send me a copy of the PDF for the official Robot Arm board set up.


Thanks,

Re: Robot Arm C

Posted: October 8th, 2015, 6:51 am
by windu34
futaba wrote:Hello,


Yes, I am helping and will be in charge of this event at several of the invitationals. Please send me a copy of the PDF for the official Robot Arm board set up.


Thanks,
What invitationals are you supervising at?

Re: Robot Arm C

Posted: October 8th, 2015, 11:59 am
by jander14indoor
futaba wrote:Hello,


Yes, I am helping and will be in charge of this event at several of the invitationals. Please send me a copy of the PDF for the official Robot Arm board set up.


Thanks,
Be careful when you get to 'official' tournaments. This board is not an official source for anything.
And be cautious when you print out any sheet to use for this event. CHECK THE DIMENSIONS! Many large scale printers don't print to true dimensions or proportions. Further, paper swells and shrinks considerably in amazingly short times. Rules refer to tape marked edges, not a printed sheet. Hate to see an appeal because you depended on a file from the official sources...

Regards,
Jeff Anderson
Livonia, MI

Re: Robot Arm C

Posted: October 10th, 2015, 9:02 am
by jander14indoor
windu34 wrote:This topic brings up a similar topic from the 2008-2009 rules for electric vehicle where teams were using dc-dc converters because of the low allowed battery voltage of the allowed battery pack. It was deemed perfectly legal and in the spirit of comp. so it is likely that it will be allowed in this event as well.
I would of course submit the official clarification and let us know what they decide.
Reminder, not official, no matter who I am, because this is just NOT the official forum for anything Science Olympiad. And the decisions are actually made by a committee.

Unfortunately I don't have the 08-09 rules for electric vehicle so can't comment on the wording that may have allowed the determination that a dc-dc converter was OK in that case.

But, I now have this years final rules for Robo-Cross. Para 3.d says: "as long as the expected voltage output across any points does not exceed 14.4" emphasis mine. In my mind 'any points' implies the CIRCUITS, not the batteries. And expected means I don't have to measure it, if as an ES I can logically deduce a voltage above 14.4V in any circuits based on the battery rated voltage as a start I have to rule that it does not meet the construction requirements.

Again, www.soinc.org is the only official source for answers to such questions on the FAQ or Clarification pages. If you haven't already asked the question there, you should still keep an eye out for answers from other peoples questions.

Regards,

Jeff Anderson
Livonia, MI

Re: Robot Arm C

Posted: October 10th, 2015, 9:54 am
by windu34
jander14indoor wrote:
windu34 wrote:This topic brings up a similar topic from the 2008-2009 rules for electric vehicle where teams were using dc-dc converters because of the low allowed battery voltage of the allowed battery pack. It was deemed perfectly legal and in the spirit of comp. so it is likely that it will be allowed in this event as well.
I would of course submit the official clarification and let us know what they decide.
Reminder, not official, no matter who I am, because this is just NOT the official forum for anything Science Olympiad. And the decisions are actually made by a committee.

Unfortunately I don't have the 08-09 rules for electric vehicle so can't comment on the wording that may have allowed the determination that a dc-dc converter was OK in that case.

But, I now have this years final rules for Robo-Cross. Para 3.d says: "as long as the expected voltage output across any points does not exceed 14.4" emphasis mine. In my mind 'any points' implies the CIRCUITS, not the batteries. And expected means I don't have to measure it, if as an ES I can logically deduce a voltage above 14.4V in any circuits based on the battery rated voltage as a start I have to rule that it does not meet the construction requirements.

Again, http://www.soinc.org is the only official source for answers to such questions on the FAQ or Clarification pages. If you haven't already asked the question there, you should still keep an eye out for answers from other peoples questions.

Regards,

Jeff Anderson
Livonia, MI
Yeah I looked over my rules and your explanation seems correct.

Re: Robot Arm C

Posted: October 11th, 2015, 11:10 am
by windu34
As far as mechanical design goes, what seems the best? I posted a chart of 5 common robotic arm designs on the wiki, but I'm curious to see what others are going with.

Re: Robot Arm C

Posted: October 13th, 2015, 6:56 pm
by peartree423
Hey so what do you guys think some of the really competitive times will be this year? Any thoughts?