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Unread 01-02-2011, 16:14
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Re: Any PID experts ?

Quote:
Originally Posted by de_ View Post
...yes, good idea, if we could design something where the effects of gravity can be neutralized (gigantic spring), I could see how the current PID class could work well but so far we don't know how to do it. So currently with the same power, going up goes slowly and controllable, going down races at high speed and gathers lots of momentum. This behaviour is a bottle neck to a super high performance (ie high speed) ladder.
You could use a gain scheduler.
Basically, you check something (your scheduling variable) and determine which gain to use.

In your case, the sign of the error. If it's positive (up?), set the gain to x, which you would tune in the up direction only, if it's negative (down), set the gain to y, which you would tune in the down direction only. You would probably set the up gain higher than the down gain, probably significantly higher if you don't have much spring force.
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