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:
Oct. 25, 2011
Filed:
Nov. 04, 2008
Robert L. Morris, Milford, MI (US);
R. Anthony Hansen, Redford, MI (US);
Michael D. Haggerty, Sterling Heights, MI (US);
Robert L. Morris, Milford, MI (US);
R. Anthony Hansen, Redford, MI (US);
Michael D. Haggerty, Sterling Heights, MI (US);
GM Global Technology Operations LLC, Detroit, MI (US);
Abstract
An improved method and apparatus for estimating driveline lash in a vehicle powertrain is provided herein. The method includes: determining if the powertrain is transitioning through driveline lash, e.g., driver commanded torque value changes sign, and then stays between a minimum and maximum commanded torque threshold for a calibrated time; if the powertrain is transitioning through driveline lash, determining when the driveline lash is taken up, e.g., when the transmission output acceleration exceeds a threshold minimum output acceleration, and thereafter changes sign; determining when the estimated lash state changes from neutral to a positive or negative state, which may be inferred from the axle torque estimate behavior; determining the time difference between when the driveline lash is taken up and when the estimated lash state changes from neutral to a positive or negative state; and updating the adaptive lash estimate if the aforementioned time difference is not equal to zero.