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:
Mar. 05, 1996
Filed:
May. 05, 1994
Michael P Bradford, Orange, CT (US);
Thomas Perrotta, Brookfield, CT (US);
United Technology Corporation, Hartford, CT (US);
Abstract
A windshield temperature control system (200) monitors aircraft operating (240) and environmental (246) conditions, and determines, based on the fixed physical properties of the windshield (250,251 ), a required film temperature necessary to produce a heat output to maintain the internal and/or external temperature of the windshield at a desired temperature. The heat output is based on a total heat loss including internal heat loss and external convective, evaporative, sensible and radiation heat loss, and a film temperature error defined as the difference (340) between required film temperature and actual film temperature is applied via proportional (355) and integral (350) control paths to produce zero steady state film temperature error. The desired external temperature is selected to be sufficiently above freezing, i.e., 0.degree. C., to prevent ice formation on the windshield, and the desired internal temperature is selected to be sufficiently above the cockpit air dew point to prevent condensation on the internal surfaces of the windshield. During start-up at low film temperature, film temperature error is filtered (315) to gradually heat up the film at a rate dependent upon the magnitude of the error. After a warm-up delay (307), film temperature error is compared to a fixed temperature error limit (385), the exceedance of which will cause termination of film heating (390) to thereby prevent over temperature of the windshield.