NONLINEAR 2-FREEDOM DEGREE PID CONTROLLER

摘要

PROBLEM TO BE SOLVED: To suppress intense fluctuation of a manipulated variable that is caused by the high frequency fluctuation of a controlled variable by setting the difference between a corrected control deviation and its target value at the controlled variables of both proportional and differential terms. ;SOLUTION: The inputted control deviation E is outputted as a corrected controlled variable PV_a by a blind sector element 1. Thus, the variable PV_a is not fluctuated even if a controlled variable PV fluctuates at a point near its target value SV and accordingly the high frequency fluctuation of a manipulated variable MV can be suppressed. A saturation element 3 is added to the input path of the deviation E against a differential element 11. Thus, a direct integrating operation is performed in a small range of the deviation E where the integrating operation is important and the generation of a steady deviation is prevented. When the deviation E exceeds its upper and lower limit value with its absolute value increased, the upper and lower limit value having their absolute value smaller than the deviation E are integrated. As a result, the integrating operation is suppressed and an excessive integral signal I is also suppressed. Then an occurrence of overshoot of the variable PV is suppressed.;COPYRIGHT: (C)1999,JPO