By Doug Cooper and Allen Houtz1
As discussed in previous articles, the purpose of the feed forward controller of the feed forward with feedback trim architecture is to reduce the impact of one specific disturbance, D, on our primary process variable, PV. An additional sensor must be located upstream in our process so we have a disturbance measurement that provides warning of impending disruption. The feed forward element uses this D measurement signal to compute and implement corrective control actions so the disturbance has minimal impact on stable operation.
Here we build on the mathematical foundation of this previous