Apparatus and method for preventing incorrect gear shifts in automatic transmissions of motor vehicles

US8108113B2 · kind B2 · utility

Assignee

• GETRAG Getriebe- und Zahnradfabrik Hermann Hagen · DE

Inventor

• Martin Seufert · Steinheim, DE

Key dates

• Filing date: Jul 30, 2010
• Grant date: Jan 31, 2012
• Expiry date: Aug 17, 2030

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2061/161
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A method (42) for preventing incorrect gear shifts in automatic transmissions (14) of motor vehicles comprising the following steps: determining a current output torque (Mis) of a source gear (GSOURCE); generating a history of output torques by storing the current output torque in the source gear (GSOURCE) for a time interval having a predetermined duration; determining an absolute value of a minimal output torque (Mmin) and an absolute value of a maximum output torque (Mmax) from the history (60) of output torques, comparing the two values and determining the greater absolute value; determining (S3) an absolute value of a target torque (MTARGET) of a target gear (GTARGET), if an instruction for a gear change exists; comparing (S4) the absolute value of the target torque (MTARGET) with the greater absolute value; and shifting (S5) the transmission (14) from the source gear (GSOURCE) to the target gear (GTARGET), if the absolute value of the target torque (MTARGET) is less than or equal to the greater absolute value (FIG. 2).