A two-channel relay for autotuning

摘要: Tuning of feedback controllers for SISO systems often starts from information about the intersection Nyquist curve and negative real axis. In standard autotuning this point is identified by a relay experiment. For many processes, however, it would be advantageous to identify on somewhere in third quadrant. The aim paper two-fold. First, noniterative procedure suggested identification an arbitrarily chosen quadrant use two-channel relay. consists two relays operating parallel process output integral output, respectively. Secondly, general priori plant knowledge, available, utilized choice between PI PID control amplitude-and-phase-margin based controller tuning.