| 摘要 |
PURPOSE:To use a PID controller with simple switching to I-PD characteristics, by changing consecutively the coefficient element. CONSTITUTION:A basic PID controller gives feedback control to a control object so as to obtain the coincidence between the degree of control and the target value. A coefficient element 30 is provided to a control system to vary the coefficients 0-1 and to control the control value. The target value SV is multiplied by alpha (0<=alpha<=1) with the element 30 and then added with the control degree -PV having an inverted code. I-PD control characteristics are obtained in the case of alpha=0; while the PID characteristics are obtained at alpha=1. Furthermore, the blended characteristics of I-PD and PID and secured at 0<alpha<1. Thus the characteristics can be varied in accordance with the request even under operation of a plant. |
