Getting more phase margin and performance out of PID controllers

Designing a PID controller to meet gain and phase margin specification is a well-known design technique. If the gain and phase margin are not specifie d carefully then the design may not be optimum in the sense that there coul d be larger phase margin (more robust) that could give better performance. This paper studies the relationship between the integral square error perfo rmance index, gain margin, phase margin and gives recommendation for gain a nd phase margin specification to get more phase margin and performance out of PID controllers. (C) 1999 Elsevier Science Ltd. All rights reserved.