I had a chance to lengthen the ramp times to see how well the PID parameters are working for my set up. Here’s the test profile:
Madtst
3, 100, 0 //step (3) setpoint to (100)
2, 0, 0 //wait (2) until it crosses the setpoint
1, 200, 300 //ramp (1) to 200 over 300 seconds
2,0,0 //wait (2) until it crosses the setpoint
1, 250, 200 // Now ramp to 250 over 200 seconds
3, 0,0 // End
The PID settings are the default:
KP = 2.0
KI = 0.5
KD = 2.0
Here is the result:
http://www.flickr.com/photos/77705680@N06/6980153500/
I confess to being unsure of which parameters affect what behavior at the moment, but I am pretty sure it can do better with some tweaking. Any suggestions on where to start?