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:
Jun. 01, 1993
Filed:
May. 22, 1991
Yukiyoshi Tani, Hitachiohta, JP;
Sadao Yanada, Hitachi, JP;
Takeshi Iwamiya, Katsuta, JP;
Takumi Kawai, Katsuta, JP;
Tadahiko Iijima, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method of and apparatus for controlling a triple-coil servo valve arranged having a tripled control system each of which is composed of components of a coil, a servo amplifier and a controller, the method of and the apparatus for controlling the triple servo valve including means for specifying the abnormality of each of the components, servo amplifier output separation means, means capable of desirably combining the components and means for compensating the servo amplifier. If two control systems of the tripled control system are faulty in such a manner that at least one coil, at least one servo amplifier or at least one controller is abnormal, the triple-coil servo is operated by combining the normal components or by compensating the servo amplifier so that the continuation of the operation of the plant is enabled. Although the operation of the plant employing the conventional structure is shut down if two systems of the tripled control system, each of which is composed of the coil, the servo amplifier and the controller, are abnormal, the continuation of the operation can be enabled according to the present invention while preventing a disturbance of the plant even if the two or the three systems are abnormal by combining normal components and by separating the output from the servo amplifier in a case where the servo amplifier is abnormal.