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:
Jan. 07, 2003
Filed:
Oct. 10, 2000
Gerhard Böckmann, Laatzen, DE;
Andreas Böhm, Wennigsen, DE;
WABCO GmbH & Co. oHG, Hannover, DE;
Abstract
A method for controlling a transmission of an engine-driven vehicle having a plurality of gears, the vehicle including a service module actuable by a driver of the vehicle to select a desired gear, the service module being connected to a transmission control system which automatically changes gears in response to actuation of the service module, the vehicle further including an engine braking system connected to the transmission control system which is actuable to brake the vehicle engine during a gear change, the method comprising: monitoring the transmission input rotational speed (N ) and the transmission output rotational speed (N ); calculating a synchronous rotational speed (N ) of the desired gear; actuating the engine braking system to reduce the rotational input speed (N ) and synchronize it with the synchronous rotational speed (N ) so that the desired gear change can be effected; and disabling the engine braking system when a predetermined switch-off threshold is reached at a point in time before an expected synchronization of the rotational speeds (N ) and (N ) occurs. In one preferred embodiment, the engine braking system is disabled when the difference (D ) between rotational speeds (N ) and (N ) becomes equal to or less than a predetermined rotational differential value (D ). In another preferred embodiment, the engine braking system is disabled at a point in time which precedes the expected time of synchronization by fixed delay time (T ) which is typical for the engine braking system. By disabling the engine braking system before synchronization of the rotational speeds (N ) and (N ) actually occurs, the method accounts for hysteresis effects and the process of changing gears is speeded up.