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:
Apr. 13, 2004
Filed:
Sep. 23, 2002
Roger Hanggi, Saline, MI (US);
Ananth Krishnan, Ypsilanti, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A method is provided for controlling an output/input speed ratio of a continuously variable transmission (CVT) plant including primary and secondary pulleys actuated by primary and secondary pressures (P ,P ,), respectively, which generate forces to move the pulleys and adjust a corresponding belt, thereby adjusting the output/input ratio. The method includes calculating a desired force ratio for the CVT plant. Desired primary and secondary pressures (P ,P ) are then determined based, in part, upon the calculated desired force ratio, and the desired P and P signals are sent to the CVT plant to control operation of the CVT plant. An actual speed ratio is calculated based on measurements of input and output speed from the CVT plant. An error signal is generated based upon the measured actual speed ratio for use in calculating a next sample time desired force ratio which is then used to calculate desired P and P signals to be sent as inputs to the CVT plant, thereby using the desired force ratio as the controlled variable in controlling the output/input speed ratio of the CVT plant.