OUTPUT HOLDING SYSTEM FOR PID CONTROLLER

• Main Authors: TEJIMA KEIZO, MURANAKA KATSUMI
• Format: Patent
• Language: English
• Published: 28.06.1988
• Subjects: CONTROL OR REGULATING SYSTEMS IN GENERAL; CONTROLLING; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS ORELEMENTS; PHYSICS; REGULATING

PURPOSE:To prevent a serious accident from occurring by holding a manipulated variable from a PID control part which enters an abnormal state among mutually relative manipulated variables from plural PID control parts at the last manipulated variable of one of other manipulated variables. CONSTITUTION:A PID controller 1 has input terminals (t) to which plural input signals are inputted and PID control parts C are connected thereto. The PID control parts C perform PID operation according to input signals to calculate and supply manipulated variables M to parts A to be operated and also supply operation value signals for detecting their abnormal states to an abnormality detecting means D. Further, a relation state setting means CS generates setting information CI and supplies it to a manipulated variable holding means H together with said abnormality detection signal DS. Then the holding means H retrieves other closely relative manipulated variables by referring to said setting information CI and holds the manipulated variable of a PID control part C which outputs the manipulated variable at the value right before an abnormal state occurs.