Re: PID on Jaguars is Illegal
 

Second on Kevin's proposal.

Re: PID on Jaguars is Illegal
 

Looks good. I suggest the following minor change:

Re: PID on Jaguars is Illegal
 

With saying that the jag in closed loop acts just like a servo wouldn't that make jags and victors illegal?

Both don't just change the voltage they switch it on and off very fast the uC and supporting circuitry fiddle with the transistors to switch the output on and off and they generate the commands themselves.

Does that mean we need to revert to spikes? I dont think they gave us enough with the kit!

Re: PID on Jaguars is Illegal
 

A very good point. However, I think the distinction may be that the firmware for the Jaguars is to some degree mutable, while I believe servo control is implemented purely in hardware.

Re: PID on Jaguars is Illegal
 

Drake,

My implication was that a jag in closed loop is highly equivalent to an RC servo. Just with external motor and sensor, and tunable PID parameters. So if a closed loop Jag is illegal, then..... The intention is to point out that we're already using independent position controllers on the robot in the form of servos.

All,

I'm informed that some rather more appropriate people are working on this issue now, so I'm going to hold off on any new posts to the Q&A for a little while. I'd like to see what transpires over the weekend before adding to the GDC's busy schedule. I'd ask that anyone else please hold off until Monday evening as well, so as to avoid complicating the situation.

Re: PID on Jaguars is Illegal
 

Except that only holds for analog servos. Digital servos implement their control in software, and some of them are even customizable/programmable in various manners.

Re: PID on Jaguars is Illegal
 

It's not unexpected that there is a review of this decision behind the scenes. As well as many volunteers, WPI, NI and particularly TI have invested in expanding the use of the Jaguars. And I thank them for that investment.

On a more general point, section 4.3 of the Game Manual includes the exhortation:
That really should be a two way street, and while the Blue Boxes have helped put context to many rules, this ruling appears to be a counter-example where over-judicious reading of the letter of a rule is elevated over the spirit.

Re: PID on Jaguars is Illegal
 

There seems to be a Booth Review in progress. Or CD complaints caused a Challenge Flag to be thrown.

The original link is no longer viewable and the answer no longer appears in the Q&A Robot section http://forums.usfirst.org/forumdisplay.php?f=1481

Re: PID on Jaguars is Illegal
 

Woohoo... Closed loop control on CAN is legal!!

Update 4

Re: PID on Jaguars is Illegal
 

{fistpump}

I can't tell you how relieved I am..

Re: PID on Jaguars is Illegal
 

c/p from team update #4:
As long as the CAN bus is wired legally so that the heartbeat from the cRIO is maintained, the closed loop control features of the Jaguar motor controller may be used. (That is, commands originating from the cRIO to configure, enable, and specify an operating point for all Jaguar closed loop modes fit the intent of <R49>.)

(our software subteam breathes a sigh of relief.)

Re: PID on Jaguars is Illegal
 

I'm glad it's legal. I was looking forward to using it this year.

Of course, after reading this thread earlier today, I spent about an hour abstracting and reworking the code.

Although it's still improved, I wish I had known earlier...:rolleyes:

Re: PID on Jaguars is Illegal
 

It's a relief to see the ruling reversed, but a pity the decision was published in the official Q&A in the first place.

Thanks to the positive contributors to this thread for raising awareness and being a part of encouraging a sensible resolution.