The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 06, 1992
Filed:
Jun. 12, 1991
Tadayoshi Saito, Hitachiota, JP;
Susumu Takahashi, Higashiibaraki, JP;
Kouji Tachibana, Katsuta, JP;
Junzo Kawakami, Mito, JP;
Nobuyuki Yokokawa, Mito, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A self-tuning controller apparatus which comprises: a control response pattern recognition portion for receiving a set-point and a controlled variable of a process and for obtaining three performance indexes from a controlled variable response pattern generated in response to a change in the set-point or a disturbance; a control parameter correction portion for qualitatively evaluating the three performance indexes and for inferring a correction value of a PID control parameter on the basis of the result of evaluation; and a control performance dissatisfaction degree evaluation portion for evaluating the inferred correction value of the PID control parameter in accordance with the dissatisfaction degrees of the two performance indexes for the respective target specifications of the two of the three performance indexes. The control performance dissatisfaction degree evaluation portion acts to make the PID control parameter converge stably. In a process control system including a plurality of vertically distributed control elements each capable of self-tuning its control parameter, the control performance dissatisfaction degree evaluation portion contributes to autonomous functioning of each of the control elements.