On 4/12/2011 6:32 PM, andy pugh wrote: > In a discussion at work last week it was mentioned that the > controllers we use in the vehicle ECUs often use a combined limit for > P and I. > > The idea is that I is limited to be never bigger than (L - P). This > means that if the controller is already maxed-out in P then there is > no I-term windup to be unwound once the setpoint is reached. > > It seems sensible, and apparently works well. > > Andy,
What is the L term? Many or most of the PID loops that I work with (usually for process control systems) have anti reset windup implemented such that once the PID output hits it's limit in a positive or negative direction, the I term is not allowed to integrate any further. Does the scheme you describe work differently? Dave ------------------------------------------------------------------------------ Forrester Wave Report - Recovery time is now measured in hours and minutes not days. Key insights are discussed in the 2010 Forrester Wave Report as part of an in-depth evaluation of disaster recovery service providers. Forrester found the best-in-class provider in terms of services and vision. Read this report now! http://p.sf.net/sfu/ibm-webcastpromo _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
