AussieJester wrote:CA Settings
Amps Limit 130amp
Low Volts limit 39v
Main Display Watts
Set Range High (0.1A)
Set RShunt .7000m0hm (using the two shunts combined as one, Justin Sent with CA)
Volt Sense 31.10V/V
PSGain 0.08V/kph <------ DEFAULT = 0.08
ISGain 200 <------------ DEFAULT = 200
AGain 300 <------------ DEFAULT = 300
VGain 800 <------------ DEFAULT = 800
ITerm Max 2.00mS
ITerm Min 1.21mS
Aux Thresh 0.75V
Whiplash wrote:Very cool to hear AJ! So, I am still a little confused about this setup, does it actually limit the current now? Or is it just that it gives better control over the throttle and makes it smoother? I guess I am wondering it if fixes the low RPM high load problems associated with the R/C speed controls?
johnrobholmes wrote:Well it certainly sounds like there are as many opinions on throttle control as there are people in here
Any way to have each type selectable on this Justin?
justin_le wrote:.... I have a feeling that without a proper damping term in the PID loop that people will have a hard time getting it to hold steady without a fair bit of overshoot and undershoot, but I would be interested to hear if anyone has experimented with it.
johnrobholmes wrote:So the RC CA can use speed mode for throttle too? Probably solves my want right there. Like a voltage throttle and then some, the automatic torque mode!
I am setting up a DPDT switch on my normal CA so that I can swap between amperage and voltage control. Both have advantages and disadvantages. I can tell you I hate the amperage throttle when I am riding with a group, absolutely do not like it. It is so much harder to keep constant speed and ride with a pack....
... On the other hand when I ride by myself I really enjoy the amp throttle. When I joyride I typically cruise at low speeds so I can double my range and enjoy the ride. Totally easy to keep a low amp draw or dial it down with a POT in amp mode and not even worry about the load that the upcoming hill will put on my pack...
But really we are splitting hairs here. Its funny that this is a main focus of the thread, and not just how awesome this product will be! Obviously the RC CA doesn't have far to go, or else there would be a lot more talk about how to improve it and what it lacks instead of the finer points of throttle control
fechter wrote:justin_le wrote:.... I have a feeling that without a proper damping term in the PID loop that people will have a hard time getting it to hold steady without a fair bit of overshoot and undershoot, but I would be interested to hear if anyone has experimented with it.
I'm not sure how hard it would be to test, but I thorize that having a fast attack, slow decay in the feedback loop can prevent a lot of the oscillation issues without sacraficing safety. Of course practice never seems to cooperate with theory.
Another more difficult approach is to use a feed forward arrangement to minimize overshoot. You have to sort of predict where the PWM needs to be in the near future based on input changes, error, and rates of change.
justin_le wrote:For someone interested in control loops and human interfaces to EV's, these are exciting finer points to hear about and see actively discussed though!
johnrobholmes wrote:justin_le wrote:For someone interested in control loops and human interfaces to EV's, these are exciting finer points to hear about and see actively discussed though!
I wish I had more people interested in this near to me. I can't really tell my girlfriend how my day went when it involves the finer points of controlling a PWM based system
Glad to be a part of the discussion, if I can help in the development otherwise just let me know.
Kepler wrote:This setup will only be used at around 30A and I figure one shunt should be fine up to 50A without a problem. This means the CA shunt value will be set to 1.4 mohm.
hjoore wrote:Hey Justin,
I just ordered a CA-LRC too for my mini friction drive system, are they still in production or is it just the test batch?
Is there a way to limit the maximum speed as well? Cause then my friction drive would be 100% legal in the Netherlands!