Speed Controller Preference
 

Did your team prefer using Jaguars or Victors last year and why?

We used Victors because we wanted to maximize space for our ball hopper and putting the electronics in a box meant it was easier to fit 9 Victors than 9 Jaguars.

Re: Speed Controller Preference
 

1618 used four Jaguars. They came in the kit and they worked (our own electrical issues aside).

2815 used, as I remember, four Jaguars and two Victors, also largely driven by availability. Jaguars went on the belts and shooter drums, Victors on the two drive motors.

Re: Speed Controller Preference
 

Team RUSH switched to all Jaguars on the competition bot last year in anticipation of being able to use the enhanced features in the near future.

I'm personally very excited about CAN and the opportunity to teach our students about it.

I currently work with CAN on a daily basis in automotive applications....and I'm positive that none of our students even know it exists or how it works inside their vehicles.

Re: Speed Controller Preference
 

We used the Jaguars where we wanted fine control (drive and shooter) and the Victors for on/off (lift belt and turret).

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Team Krunch used four jaguars for drive and four victors for manipulation on our robot. In addition to availability we considered weight and ease of replacement/addition. We had spots made for up to 10 victors on our board.

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Yeah I can honestly say I hadn't the slightest clue it existed until hearing about it when they unveiled the new equipment at Atlanta in 2008.

Re: Speed Controller Preference
 

The ausTIN CANs used 6 Jaguars and 2 Victors. The Jags went to our 3-wheel swerve drive, and the Victors were on our turret and shooter. We also had two Spikes on our lift (one feeding roller and one belt).

Personally, I'm very impressed with the Jaguars, more so than the Victors. We've been careful enough (in general) not to kill any motor controllers this year other than individuals' mistakes, but the Jaguars have kept cooler and provided more consistent and linear power than the Victors. I'm also very excited about using the CAN bus next year, it'll be great to teach serial communication protocols (none are really being taught from the ground up, even in FIRST, all of the networking is embedded deep in the magic boxes).

Re: Speed Controller Preference
 

399 used 2 jaguars for the drive.
The only victor that we had was for the conveyor,
we only really ran it at full speed so the low speed capabilities of the jaguars weren't needed for it.

(We also had a spike for the dumper)

We only broke one jaguar, and it was a defective one.
Powered on and smoke blew everywhere.

Re: Speed Controller Preference
 

Jaguars. They're a little bit bigger, but their output is a Lot more controllable. Color-coded screws are a bit more fool-resistant.

We used 2 Jags and 4 Victors in 2009

Re: Speed Controller Preference
 

During competition season we used 4 Jaguars (2 drive, 1 pickup, 1 dump) and 1 Victor (for the second dump motor). We have to use the one victor simply because we ran out of room and needed a second motor for our dumper to work effectively.

We had no problems with the Jaguars all season...

Then when we started making enhancements for IRI we replaced the 4 Jaguars with 4 Victors. We made this switch because we needed the extra real-estate to make room for traction control hardware. We fit 5 Victors (with room for one more) in the same foot print the 4 Jaguars previously occupied.

We haven't made a determination on what we'll use for 2010 since we don't know what will be available and what our size constraints will be.

Re: Speed Controller Preference
 

I'm really excited about CAN. I think that about 10% of teams will really dig into it this year, and that they will create some solutions with it that (although not game changing) will make us rethink a few common design memes. Hopefully the year after, newer teams will benefit from "how you CAN make your robot drive straight" tutorials.

I'm not saying that CAN will let you do things that are impossible now, I'm just hoping it lowers the ((entrance)) bar for some of the fundamentals.

Re: Speed Controller Preference
 

Most of the features that the CAN bus allows us to do are easily doable now.
The speed (Voltage) control mode, is the mode we are using through PWMs.
The Analog position input (Potentiometer)
has been done by almost everyone using an arm (PID control)
The Encoder position control
Can be done this year, use a PID controller and have your setpoint be a # of ticks
Limit switches - Digital input,
if(input && (abs(speed)/speed) == limitDirection) motor.set(0.0);
else motor.set(speed);


Though, the real advantage of using CAN is that the Jags handle the monitoring, and control internally.

Which can provide the fastest response possible in a closed loop.
(At least with the motors & controllers we can use)

And any faults can be read by the RIO,
ex: does that red slow blink mean the limit switch has been triggered or is the jaguar dead?
Conditions like: over-current, under voltage (ie 6v from battery), limit switch, or over temperature; can easily be read from like the driverstation LCD instead of guessing.

Also having access to all the motors variables (current, voltage, torque, speed) without having to put in a large coil of wire for a current sensor is nice.


http://www.luminarymicro.com/products/mdl_bdc.html
BD-BDC-DS-01 Datasheet for Brushed DC Motor Control Module

Re: Speed Controller Preference
 

We used 8 Victors, simply because Jaguars would not fit, and were not aesthetically pleasing in our design.

EDIT: Also, we already had plenty of Victors from previous seasons, whereas we would have needed to purchase more Jaguars.

Re: Speed Controller Preference
 

We used both last year, Jags on the drive train, victors on everything else.

Victors; Tried and true, fairly bullet-proof.

Jaguars; Nice linear response, motors were much quieter with higher frequency response, held up well so far. Waiting for CAN bus to hopefully simplify wiring.

We're happy with both, hopefully we will be allowed to continue to choose which controller we wish to use for our specific applications.

Re: Speed Controller Preference
 

We ended up using Victors last year, mostly because all of our Jaguars fried pretty quick. We'll probably be using Victors again this year, as well.