View Single Post
Old 10-09-2015, 08:46 AM   #2158 (permalink)
MPaulHolmes
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,368
Thanked 1,135 Times in 749 Posts
The used up data memory isn't actually as used up as it seems. A lot of it is tied up in some debugging arrays that I'm using. I just made them as big as possible so that all the memory was used up. It's in a UNION in sensorless.h. As for MOSTLY frozen things, that's a good question. A couple functions in UART are constantly changing as new commands are added and taken away. Also, I keep changing the commands to really short stuff so I don't have to type so much while testing.

In the rest of the code, initialization code is pretty frozen. startup sequence is frozen. I need to automate the PI loop tuning (for all motor types) and finding of rotor time constant for case of ACIM.

To get the resolver board to work, you would replace the encoder initialization with configuring 2 of those inputs as A/D inputs. Then, maybe you could do these 4 A/Ds:

throttle
CURRENT 1
CURRENT 2
RESOLVER 1

and then one time of this:

THROTTLE
CURRENT 1
CURRENT 2
RESOLVER 2

and then back to this:
throttle
CURRENT 1
CURRENT 2
RESOLVER 1

The trouble is, AN0 is throttle, AN1 is current 1, AN2 is current 2. For the 4 simultaneous samples, AN0, AN1, AN2 must be together, and then ANx is the most flexible. unfortunately, I chose AN0 to be throttle. It would have been better to have throttle be ANx (for some x not equal to 0, 1, or 2) since it doesn't have to be done as often.

The noise on the throttle is maybe +/- 1 (sometimes 1.5) A/D ticks out of a range of 1024, which doesn't need a whole lot of oversampling.

So, we could either alternate with resolver 1 and resolver 2 (I'm sure you could infer about the angle by getting alternating sine and cos values for the angle), or you could move the throttle with a little wire over to ANx, and then wire, say, resolver 1 to where the throttle used to be, and then once every 32 times check the throttle, and 31/32 times check resolver 2?

edit: maybe the alternating sine and cos isn't so bad... the only time you need both pieces of info is when you aren't sure about what quadrant you are in.
__________________
kits and boards

Last edited by MPaulHolmes; 10-09-2015 at 08:53 AM..
  Reply With Quote
The Following 2 Users Say Thank You to MPaulHolmes For This Useful Post:
e*clipse (10-09-2015), thingstodo (10-09-2015)