Ramping Motors?

[Ether]

Originally Posted by arithehun

Of course there's a jumper solution. Why didn't I think of it?

It depends on what you want the ramping to do for you.

In PWM mode, the ramp is 0.06 seconds from neutral to full throttle.

That's enough to reduce the occurrence of Jag overcurrent trips.

But if you're trying to change the feel of the driver interface it's probably not going to help.

[Azrathud]

Originally Posted by Ether

It depends on what you want the ramping to do for you.

In PWM mode, the ramp is 0.06 seconds from neutral to full throttle.

That's enough to reduce the occurrence of Jag overcurrent trips.

But if you're trying to change the feel of the driver interface it's probably not going to help.

I thought you could change values using a serial interface(just a one time connection) using the BDC-COMM software and then have it work for PWM.

[arithehun]

Oh, sweet, I just downloaded the software. I am using PWM, so that's really helpful.

[Ether]

Originally Posted by Azrathud

I thought you could change values using a serial interface(just a one time connection) using the BDC-COMM software and then have it work for PWM.

If that's true, it's good to know.

Q8 & Q9 in the FAQ seem to be saying that the factory "preset value" cannot be changed, and will be used every time the Jag is power cycled. Could someone who has actually done it please confirm?

[arithehun]

Q8 & Q9 in the FAQ seem to be saying that the factory "preset value" cannot be changed, and will be used every time the Jag is power cycled. Could someone who has actually done it please confirm?

It also mentions that it only resets the ramp rate if the automatic mode is enabled. You can disable the mode, it says in your second thumbnail.

[Ether]

Originally Posted by arithehun

It also mentions that it only resets the ramp rate if the automatic mode is enabled. You can disable the mode, it says in your second thumbnail.

If you disable it, it doesn't function in PWM mode. So it's not clear what point you are making. e.g. I have a car with a dead battery. It works fine unless I try to start it.

[dyanoshak]

Originally Posted by Azrathud

I thought you could change values using a serial interface(just a one time connection) using the BDC-COMM software and then have it work for PWM.

No, you can't save a ramp rate and have it stick after a power cycle. The only configuration parameter that is saved in flash (immune to a power cycle) is the Jaguar ID.

The idea behind the Automatic Ramp Mode was to give teams a quick way to prevent high current spikes without having to write code or hook up the CAN/Serial interface.

If you need the ability to tweak your ramp rate, you either need to use CAN/Serial the whole time or write a ramp into your PWM code.

-David

[arithehun]

PWM is stupid, I'm switching to CAN. Unfortunately, I didn't request CAN when I ordered, so now I have to buy the RS232-RJ11 and RJ11-RJ11 cables. Oh well...

[jesusrambo]

If you don't want to use CAN and you still want ramping, you can modify the source file for the Jaguar class to just average out speeds over the last 20 ms or so before setting the output speed.

[arithehun]

Yeah, but now that I read up on it, I may want to use the jaguar PID modules too to keep my own code as clean as possible.