| Title |
Performance Improvement for PID Controllers by using Dual-Input Describing Function (DIDF) Method |
| DOI |
https://doi.org/10.5370/KIEE.2011.60.9.1741 |
| Keywords |
PID controller tuning ; Dual-Input Describing Functions |
| Abstract |
Though various techniques have been studied as a way of adjusting parameters of PID controllers, no perfect method of determining parameters is available to date. This paper proposes a new method for enhancing performance of PID controllers by using the characteristics of dual-input describing function (DIDF). In other words, if nonlinear elements with two inputs (DIDF) are connected in series to the plant, the critical point (-1+j0) for Nyquist stability theory can be moved to a position arbitrarily selected on the complex plane by determining necessary coefficients of the DIDF appropriately. This makes the application of the existing conventional PID parameter tuning methods a lot easier, and stability and robustness of the system are improved simultaneously due to the DIDF inserted. |