I typically will just "roll my own". Draw it out on paper first. Graph out X vs Y and put some theoretical data points on it and do some math to see what you need to get there. Then start to code it. A few questions to consider first
o you want to always ramp over a fixed period of time? Say 30 seconds? Or could that be variable? Or is it more important that you ramp at a constant rate, say 5rpm/sec?
Sounds like your ramp up speed will be a variable, so to determine how you want to ramp your lag pump, what is important? Time? Rate? If you have a fixed time, your ramp rate will change based on what you ramp too. If you need to ramp at a constant speed your time will change to achieve the ramp speed will change. Heck, it may not matter and you just need to choose, or 'sometimes' it might be one or the other, then you'll have to provision for it.
Put it on paper, keep your algebra friend y=mx+b in the room go from there. I find y=mx+b is extremely useful in the process world, I've used it to do quite a bit beyond simple analog scaling. Of course there are plenty of ways to do this but putting it on paper first always makes it easier.
EDIT: At least for me, the pictures are to small can't read the text very well. Try putting the program in a window mode and zoom in on the ladder, then screen capture and upload.