Go to Post Like a moth to a flame, true FIRSTers are attracted by the Victor instead of the Banner. - Rich Wong [more]
Home
Go Back   Chief Delphi > Technical > Electrical
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 03-02-2012, 18:09
Doc543's Avatar
Doc543 Doc543 is offline
Electrical, Pneumatics, Driver
AKA: Eric
FRC #1891 (BullBots)
Team Role: Programmer
 
Join Date: Mar 2010
Rookie Year: 2009
Location: Meridian Idaho
Posts: 63
Doc543 is an unknown quantity at this point
single lline encoder on Jags

can we use a single line encoder like a gear tooth encoder or an optical encoder with the Jags?
__________________

"Its just a prototype."
2011 Chairman's Award Utah Regional
2010 Gracious Perfectionism Utah Regional
2009 Gracious Perfectionism Portland Regional
  #2   Spotlight this post!  
Unread 03-02-2012, 18:19
mikets's Avatar
mikets mikets is online now
Software Engineer
FRC #0492 (Titan Robotics)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2008
Location: Bellevue, WA
Posts: 675
mikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of light
Re: single lline encoder on Jags

I don't see why not as long as you tell the Jag "number of lines per revolution".
__________________
  #3   Spotlight this post!  
Unread 03-02-2012, 18:39
EricVanWyk EricVanWyk is offline
Registered User
no team
 
Join Date: Jan 2007
Rookie Year: 2000
Location: Boston
Posts: 1,597
EricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond repute
Send a message via AIM to EricVanWyk
Re: single lline encoder on Jags

Quote:
Originally Posted by mikets View Post
I don't see why not as long as you tell the Jag "number of lines per revolution".
Have you tried this?
  #4   Spotlight this post!  
Unread 03-02-2012, 18:51
mikets's Avatar
mikets mikets is online now
Software Engineer
FRC #0492 (Titan Robotics)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2008
Location: Bellevue, WA
Posts: 675
mikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of light
Re: single lline encoder on Jags

We have connected our 250-line encoders to the Jags. They worked as expected. We are doing speed control on it although we did not use the Jaguar's built-in PID. We used our own PID controller library in the cRIO.
__________________
  #5   Spotlight this post!  
Unread 03-02-2012, 18:56
EricVanWyk EricVanWyk is offline
Registered User
no team
 
Join Date: Jan 2007
Rookie Year: 2000
Location: Boston
Posts: 1,597
EricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond repute
Send a message via AIM to EricVanWyk
Re: single lline encoder on Jags

Ah! You mean lines as in counts, but he means lines as in wires.
  #6   Spotlight this post!  
Unread 03-02-2012, 18:57
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 8,125
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: single lline encoder on Jags

Quote:
Originally Posted by mikets View Post
We have connected our 250-line encoders to the Jags. They worked as expected.
Did you connect both channels? Or just one (the OP's question).

Quote:
We are doing speed control on it although we did not use the Jaguar's built-in PID. We used our own PID controller library in the cRIO.
Am I understanding correctly: You connected the encoder to the Jag, then using CAN you read the speed from the Jag, then used that speed as the feedback to a PID on cRIO, then used the cRIO's PID output to command the Jag?

  #7   Spotlight this post!  
Unread 03-02-2012, 19:02
Joe Ross's Avatar Unsung FIRST Hero
Joe Ross Joe Ross is offline
Registered User
FRC #0330 (Beachbots)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1997
Location: Los Angeles, CA
Posts: 8,600
Joe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond reputeJoe Ross has a reputation beyond repute
Re: single lline encoder on Jags

According to the jaguar getting started guide:

Quote:
Speed control can be implemented with either an encoder or with a simple tachometer sensor. If a tachometer sensor is used (such as a gear-tooth sensor), then the signal should be connected to the Encoder ‘A’ input signal, with the ‘B’ and ‘I’ input left unconnected.
There is no mention of the same thing in position mode. I have not tried it in either mode.
  #8   Spotlight this post!  
Unread 03-02-2012, 19:05
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 8,125
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: single lline encoder on Jags

Quote:
Originally Posted by Joe Ross View Post
There is no mention of the same thing in position mode.
With a single channel tach input, the Jag cannot tell what the direction is. So position control would be problematic.

  #9   Spotlight this post!  
Unread 03-02-2012, 19:06
mikets's Avatar
mikets mikets is online now
Software Engineer
FRC #0492 (Titan Robotics)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2008
Location: Bellevue, WA
Posts: 675
mikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of light
Re: single lline encoder on Jags

Quote:
Originally Posted by Ether View Post
Did you connect both channels? Or just one (the OP's question).
I am not sure I understand your question. Are you asking if we connected both A and B? If so, yes.
Quote:
Originally Posted by Ether View Post
Am I understanding correctly: You connected the encoder to the Jag, then using CAN you read the speed from the Jag, then used that speed as the feedback to a PID on cRIO, then used the cRIO's PID output to command the Jag?
Yes, that's correct. We call the Jag to read the speed and use that as the Input to our PID controller on the cRIO. By doing so, we can change the PID algorithm to give us a stable speed control.
__________________
  #10   Spotlight this post!  
Unread 03-02-2012, 19:11
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 8,125
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: single lline encoder on Jags

Quote:
Originally Posted by mikets View Post
I am not sure I understand your question. Are you asking if we connected both A and B?
Yes, that's what I was asking, because I think that's what the OP was asking: whether or not it would work with one-channel input (rather than quadrature). Joe just answered that question affirmatively. The single channel must go to the A channel input.

  #11   Spotlight this post!  
Unread 03-02-2012, 19:13
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 8,125
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: single lline encoder on Jags

Quote:
Originally Posted by mikets View Post
We call the Jag to read the speed and use that as the Input to our PID controller on the cRIO. By doing so, we can change the PID algorithm to give us a stable speed control.
Interesting. Can you read the speed from the Jag, compute the new output on the cRIO, and issue a new command to the Jag, all within the same TeleOp cycle?

  #12   Spotlight this post!  
Unread 03-02-2012, 19:13
mikets's Avatar
mikets mikets is online now
Software Engineer
FRC #0492 (Titan Robotics)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2008
Location: Bellevue, WA
Posts: 675
mikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of light
Re: single lline encoder on Jags

Quote:
Originally Posted by Ether View Post
Yes, that's what I was asking, because I think that's what the OP was asking: whether or not it would work with one-channel input (rather than quadrature). Joe just answered that question affirmatively. The single channel must go to the A channel input.
Sorry for the confusion, I was answering the second part of his question whether I can use an optical encoder for which I assume is the KOP encoder.
__________________
  #13   Spotlight this post!  
Unread 03-02-2012, 19:15
mikets's Avatar
mikets mikets is online now
Software Engineer
FRC #0492 (Titan Robotics)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2008
Location: Bellevue, WA
Posts: 675
mikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of light
Re: single lline encoder on Jags

Quote:
Originally Posted by Ether View Post
Interesting. Can you read the speed from the Jag, compute the new output on the cRIO, and issue a new command to the Jag, all within the same TeleOp cycle?
Yes, we have achieved pretty stable speed control with it.
__________________
  #14   Spotlight this post!  
Unread 07-02-2012, 21:09
MikeE's Avatar
MikeE MikeE is offline
Wrecking nice beaches since 1990
no team (Volunteer)
Team Role: Engineer
 
Join Date: Nov 2008
Rookie Year: 2008
Location: New England -> Alaska
Posts: 381
MikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond reputeMikeE has a reputation beyond repute
Re: single lline encoder on Jags

Interesting.
We haven't been getting a reliable reading from the Jag when the sprocket is stationary. What language are you using (we've seen some unimplemented features in Java in previous years).

Thanks.
  #15   Spotlight this post!  
Unread 07-02-2012, 21:58
mikets's Avatar
mikets mikets is online now
Software Engineer
FRC #0492 (Titan Robotics)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2008
Location: Bellevue, WA
Posts: 675
mikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of lightmikets is a glorious beacon of light
Re: single lline encoder on Jags

We are using Wind River C++. We just call CANJaguar::GetSpeed().
__________________
Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 19:59.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi