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:
Aug. 23, 1988
Filed:
Dec. 08, 1986
Leon Krukoski, Coventry, CT (US);
Richard F Laprad, South Windsor, CT (US);
United Technologies Corporation, Hartford, CT (US);
Abstract
A gas turbine engine control system which regulates fuel flow based upon a schedule which is a function of a primary parameter, such as engine pressure ratio, switches to a schedule based upon a secondary parameter, such as compressor speed, upon the inability to function in the primary parameter mode. Upon switchover to the secondary parameter mode the scheduled value of the secondary parameter is down-trimmed to make it equivalent to the last known good value of the primary parameter so that the engine will not experience a sudden change in power level upon switchover. The down-trim is limited. When the primary mode failure occurs during a transient the down-trim is limited to the difference between a scheduled reference value of the secondary parameter and a value of the secondary parameter calculated immediately preceeding loss of the primary parameter mode and based upon a known relationship between the primary and secondary parameter. The down-trim limit assures a smooth transition from the primary to the secondary control mode when the switchover occurs during an engine transient.