Possible bad Jaguar.... Thoughts?

[Jon Stratis]

Slow flashing red indicates one of the following fault conditions:
- Power supply under-voltage
- Over temperature
- Over current
- Limit switch activated in the current direction of motion

also,

When a fault condition occurs, the motor shuts down and the LED indicates a fault state during the fault condition and for 3 seconds after the fault cause is cleared (except for the limit switch fault, which is cleared instantly). A slow flashing Yellow LED indicates that the MDL-BDC24 is not receiving a valid control signal.

this is available on the getting started guide posted here: http://www.luminarymicro.com/jaguar

So, lets walk through it... you replaced the battery with a known good one, so it's likely not under-voltage. You said it usually happens after a short period of driving, which makes me guess it's not over temperature.

Can you check the limit switch jumpers? Is it possible one of them is loose, and jarring the robot in that direction is causing it to slip out of place? i figure this is probably unlikely, but you never know...

That leaves us with over current. Switching directions from full forward to full reverse (or full reverse to full forward) makes your drive train have to work incredibly hard - you have a lot of mass moving in one direction, and now your trying to pull it in the opposite direction. If you have high traction wheels, or some slop in your drive train, this can cause the motors to stall - pulling up to 133A for a CIM motor. I would take a close look at your drive train and ensure there's no slop or any way for the motor to stall on that side. Depending on your drive train setup, it may only be binding in one direction, which is why you can go fwd-rev just fine, but rev-fwd is a problem.

[PhilBot]

I concur with all of this.

I'll double check the jumpers and drive wheels, but I just can't accept that the driving forces I'm putting the robot through should be sufficient to trip the over current fault. If so, then other teams are also going to have a lot of trouble. It just seems to happen to fast, too easilly.

I don't suppose the current limit is configurable (and mine got set too low).

Phil.

Originally Posted by eagle33199

Slow flashing red indicates one of the following fault conditions:
- Power supply under-voltage
- Over temperature
- Over current
- Limit switch activated in the current direction of motion

also,


this is available on the getting started guide posted here: http://www.luminarymicro.com/jaguar

So, lets walk through it... you replaced the battery with a known good one, so it's likely not under-voltage. You said it usually happens after a short period of driving, which makes me guess it's not over temperature.

Can you check the limit switch jumpers? Is it possible one of them is loose, and jarring the robot in that direction is causing it to slip out of place? i figure this is probably unlikely, but you never know...

That leaves us with over current. Switching directions from full forward to full reverse (or full reverse to full forward) makes your drive train have to work incredibly hard - you have a lot of mass moving in one direction, and now your trying to pull it in the opposite direction. If you have high traction wheels, or some slop in your drive train, this can cause the motors to stall - pulling up to 133A for a CIM motor. I would take a close look at your drive train and ensure there's no slop or any way for the motor to stall on that side. Depending on your drive train setup, it may only be binding in one direction, which is why you can go fwd-rev just fine, but rev-fwd is a problem.

[Joe Ross]

Every time I've tripped the overcurrent protection, it's been because of a loose wire somewhere in the electrical system related to that jaguar.

[PhilBot]

Interesting.

OK, I'll double check that as well. Maybe a badly inserted wire in a WAGO.

Phil.

Originally Posted by Joe Ross

Every time I've tripped the overcurrent protection, it's been because of a lose wire somewhere in the electrical system related to that jaguar.

[Bot190]

Going along with the over current thing, The jaguars will hold 60Amps for 2 seconds, its possible that you are exceeding the current limit on the jaguars and they are shutting off. If that is the case, then they should start responding to inputs, and the LED should stop blinking after 3 seconds.

[PhilBot]

I wondered what the hold time was.
The fault is occuring well before 2 seconds elapses.

eg: I'll be driving along at 50% power (very low load) and then do a snap reversal. The left motor cuts out immediately, causing the robot to spin, rather than reversing.

Hmmm.

The LED does stop blinking after about 3 seconds, but that doesn't indicate the specific cause as a current limit.

Originally Posted by Bot190

Going along with the over current thing, The jaguars will hold 60Amps for 2 seconds, its possible that you are exceeding the current limit on the jaguars and they are shutting off. If that is the case, then they should start responding to inputs, and the LED should stop blinking after 3 seconds.

[dyanoshak]

Originally Posted by PhilBot

I don't suppose the current limit is configurable (and mine got set too low).

The current limit is not configurable, but the fault shut-off time is. You can set the fault shutoff time as low as 500 ms.

I am not familiar with the proper WPI Library calls to set this parameter, maybe someone else can comment.

Originally Posted by PhilBot

The fault is occuring well before 2 seconds elapses.

The over current protection uses a timer to count how long the Jaguar is operating above the limit. This timer follows an exponential equation that intersects at 60A and 2 seconds. Above 60A the Jaguar will shut off at exponentially smaller time periods. For >100A the time until shutoff is quite short.

-David

[lucoytoa]

Originally Posted by dyanoshak

The current limit is not configurable, but the fault shut-off time is. You can set the fault shutoff time as low as 500 ms.

I am not familiar with the proper WPI Library calls to set this parameter, maybe someone else can comment.



The over current protection uses a timer to count how long the Jaguar is operating above the limit. This timer follows an exponential equation that intersects at 60A and 2 seconds. Above 60A the Jaguar will shut off at exponentially smaller time periods. For >100A the time until shutoff is quite short.

-David

We're experiencing this same problem. Where in Labview can we change this?

[kamocat]

Originally Posted by lucoytoa

We're experiencing this same problem. Where in Labview can we change this?

This is a CAN-only feature.
You can adjust it with the "config fault time" function in Actuators > Motors > CAN.

[hydrocannon]

bad jaguars we lost three out of four in the last few days and last night we realized the crio was recieving twice has much power has it suposed too could are jaguars been because they were recieving to much power?

[Al Skierkiewicz]

hydro,
There is no way for you to supply twice as much power to the Crio. It should be connected to the +24 volt output connector on the PD. This is the highest voltage on the robot. Everything else is either 12 volts or below. The Jaguars receive no power from the Crio.