.~.~ With rate (P. I. D.) (e.g., reset windup prevention)
DEFINITION
Classification: 318/610
(under subclass 609) Subject matter in which a third error detector is provided which detects the rate of change of the position and contributes what is termed a "rate" or "differential" control to the system. This rate signal is also summed with the two previous signal to provided a composite system error signal.
(1) Note. In the systems classified herein, the "rate" or "differential" control is provided to increase short system stability and is really a special form or a "leaf" circuit. A "lead" circuit is any electrical circuit which differentiates.
(2) Note. In the systems classified herein, the "rate" or "differential" control is often provided to prevent "reset windup". "Reset windup" is an art term which means that the system is unstable when subjected to quickly changing error signals.
SEE OR SEARCH THIS CLASS, SUBCLASS:
621, for systems which include lead and/or lag compensation.
