Method for operating a vehicle drive train

US8788163B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Jörg Arnold · Markdorf, DE
• Klaus Steinhauser · Kreßbronn, DE
• Valentine Herbeth · Friedrichshafen, DE
• Christian Popp · Kreßbronn, DE

Key dates

• Filing date: Mar 31, 2010
• Grant date: Jul 22, 2014
• Expiry date: Jun 8, 2031

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2306/46
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A method of operating a vehicle drive-train with an engine and a transmission during a gearshift in which an interlocking shift element is disengaged and a frictional shift element is engaged. Upon a shift command, the shifting time and a transmission input speed are monitored. If the input speed deviates from a synchronous speed equivalent to the gear ratio being disengaged, recognizing disengagement of the interlocking shifting element. If an engaged operating condition of the interlocking shifting element to be disengaged is detected, after the lapse of a time interval beginning with the shift command, a current drive torque of the drive machine is brought by motor actuation to a level that corresponds to a difference between the current transmission input torque and a torque that can be transmitted by the frictional shifting element to be engaged, operating with slip, plus a torque offset value.