Frequency-domain PID tuning strategy with specified safety margins using linear programming method

In this paper, a linear programming method is adopted to numerically search the entire admissible PID settings in the frequency domain. The results are demonstrated in the coefficient plane and the coefficient space. Henceforth, the relationship between the PID coefficients and the specifications in terms of gain margin and phase margin to be satisfied is shown graphically. The developed method characterizes all the solution sets in the parameter plane according to the pre-specified specifications, and it also facilitates the tuning process effectively. This alternative PID tuning strategy provides a systematic design procedure. It can be evolved as a subject in the teaching course for control education. Copyright (C) 2000 IFAC.