Criteria for Design of PID Controllers

This paper treats robustness constraints and performancecriteria for design of PID controllers. It is shown that robustnessconstraints are essential, and that controller design basedon maximization of performance criteria without robustnessconstraints give poor controllers. It is also shown thatthe robustness constraints have a significant influence on theperformance, and that the performance often can be increasedsignificantly by reducing the robustness constraints.Some comments relating to industrial practice are offered in thiscontext