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:
Sep. 02, 2014
Filed:
Jan. 25, 2011
Ali K. Naqvi, White Lake, MI (US);
Syed Naqi, Dearborn, MI (US);
Ali K. Naqvi, White Lake, MI (US);
Syed Naqi, Dearborn, MI (US);
GM Global Technology Operations LLC, Detroit, MI (US);
Abstract
A method is provided to detect the presence of hydraulic line pressure in a hydraulic control system in an electromechanical transmission. The method includes determining an estimated hydraulic line pressure of the hydraulic control system based upon an input flow and an output flow of hydraulic fluid. The input flow and output flow are regulated with a pressure control device, which is energizable on operator demand. A pressure detection device is fluidly connected to the pressure control device to detect the presence of hydraulic pressure. An override module is applied to the estimated hydraulic line pressure to determine a corrected hydraulic line pressure. The override module sets the corrected hydraulic line pressure to predetermined values based on the operating state indicated by the pressure detection device. The override module corrects for an over-estimation of hydraulic line pressure in operating conditions such as low environmental temperatures.