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:
May. 01, 2007
Filed:
Feb. 09, 2005
Matthew D. Whitton, Howell, MI (US);
Robert L. Williams, Holly, MI (US);
Matthew D. Whitton, Howell, MI (US);
Robert L. Williams, Holly, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
The present invention provides a method and apparatus for mathematically calculating an optimal transmission input torque value for the inertia phase and the torque phase of a ratio change. Engine output is then altered by an amount necessary to change the actual value of the transmission input torque to the calculated optimal value of transmission input torque. The timing of the clutch elements during the power-on skip through neutral downshift is established by calculating delay periods for the off-going and on-coming clutches such that a predetermined desired shift time is met. The power-on skip through neutral downshift is thereafter adaptively controlled so that aberrations are diagnosed and corrected during subsequent downshifts. The invention is carried out by monitoring engine and/or transmission characteristics including input speed, output speed and shift duration during a downshift and identifying departures from acceptable patterns. Each type of departure calls for a particular remedy, and a suitable adjustment is calculated thereafter implemented by changing one or more initial conditions for the next shift of the same type.