Engineers Studio #82 -- PID Algorithms Only Work When . . .

Terry Denery demonstrates that PID Algorithms only work when they act like good open-loop feedforward algorithms. How can this be? PID's are the classic implementation of the feedback approach. The assertion reflects a fundamental truth, which is carried by Newton's Law F = m*a. It means that the system is going to move the same whether F is generated by a feedforward or feedback algorithm.