the servos we are using are inland kollomorgan. They have a tachs and we fitted 2540 line encoders on the back. (originally they had resolvers)
(that is a 6 inch micrometer for scale)
When we scored the AMC drives - we decided to do a velocity inner loop (tach back to the amp) so emc only had to worry about the position loop. (initally we where going to just use the encoder with the amps in voltage mode). I have to say - I am very impresses with dual loop systems. very easy to tune and stable (as you can see from the above video). With the amps tuned correctly - so that lets say 1v = 20ipm - setting the scales correctly in emc2 - There is very little PID effect - when FF1 is 1.
it is a conventional control loop
<- <- <- Tach
Emc2 -> Mesa +/-10v -> Amc drive -> Servo -> encoder -> Mesa encoder interface -> Emc2
The encoders we are using are single ended. We figured we might have issues with the distances we are running - we did. Anything over about 50ipm and we start to lose position. We purchased line drivers from digikey. n so far so good (the mesa card will do both single ended and differential encoders)
The tool chain was all done in ladder.
emc calls for a certain tool number
unclamp tool chain
Chain starts moving high speed.
The tool reader wipes by the tool - all the 'bits' are latched
The bits are converted to a number
on the leading edge of the tool chain prox detector - the read number is compared to emc's number - if different - keep looking.
if the read number matches emc - activate chain creep.
Count 2 more leading edges of the prox detector
Tell emc - tool is found.
(that is from memory - so I might have missed something)
The spindle has a 16 speed gearbox that is run by 4 spool valves. (4 bit logic 0 - 15 = 16 speeds)
I am writing a comp for this (hal component) It is going pretty smooth and have something that I can test once we get the vfd hooked up agian.