Transmission control system

Patent metadata

Field	Value
Publication number	US-10844953-B2
Application number	US-201916250299-A
Country	US
Kind code	B2
Filing date	Jan 17, 2019
Priority date	Jan 18, 2018
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A gearbox ( 100 ) includes an input shaft ( 105 ) and a first and a second proportionally controllable shift element (A to F). The shift elements (A to F) are configured to control, by way of an open-loop system, engagement or disengagement of a gear ratio in the gearbox ( 100 ). A method ( 200 ) for the open-loop control of the gearbox ( 100 ) includes: determining a specified differential speed profile that is a profile of a difference between a rotational speed of the input shaft ( 105 ) and a synchronous speed of a gear ratio to be engaged; and determining a torque demand of a drive source connected to the input shaft ( 105 ) or determining a control profile for the one of the first and second shift elements (A to F) to be engaged in the gear ratio on the basis of the specified differential speed profile.

First claim

The invention claimed is:

1. A method ( 200 ) for open-loop control of a gearbox ( 100 ) that includes an input shaft ( 105 ), a first proportionally controllable shift element (A to F), and a second proportionally controllable shift element (A to F), the method ( 200 ) comprising:
determining ( 210 ) a specified differential speed profile that is a profile of a difference between a rotational speed of the input shaft ( 105 ) and a synchronous speed of a gear ratio to be engaged;
determining ( 225 ) a torque demand of a drive source connected to the input shaft ( 105 ) or determining ( 230 , 235 ) a control profile for the one of the first and second shift elements (A to F) to be engaged in the gear ratio on the basis of the specified differential speed profile; and
synchronizing the gearbox ( 100 ) based at least in part on one or both of the determined torque demand of the drive source and the determined control profile for the one of the first and second shift elements (A to F) to be engaged.

2. The method ( 200 ) of claim 1 , wherein determining ( 210 ) the specified differential speed profile comprises determining ( 210 ) the specified differential speed profile with respect to a predetermined slip time.

3. The method ( 200 ) of claim 1 , wherein the open-loop control ( 225 - 235 ) is performed such that an actual differential speed profile essentially corresponds to the specified differential speed profile, and the actual differential speed profile includes a profile of a difference between the rotational speed of the input shaft ( 105 ) and the synchronous speed.

4. The method ( 200 ) of claim 1 , wherein the torque demand ( 225 ) and the control profile ( 230 , 235 ) are determined with respect to different further control parameters, each of the different further control parameters determined as a function of one or both of a temperature of the gearbox and a torque to be transmitted.

5. The method ( 200 ) of claim 1 , wherein the torque demand or the control profile is determined with respect to one further control parameter ( 225 - 235 ), and the one further control parameter ( 225 - 235 ) is determined as a function of a temperature of the gearbox ( 100 ).

6. The method ( 200 ) of claim 1 , wherein the torque demand or the control profile is determined with respect to one further control parameter ( 225 - 235 ), and the one further control parameter ( 225 - 235 ) is determined as a function of a torque to be transmitted.

7. The method ( 200 ) of claim 1 , wherein determining ( 225 ) the torque demand or determining ( 230 , 235 ) the control profile begins when a start condition for an open-loop control is met, and the open-loop control holds the gearbox ( 100 ) at a synchronization point.

8. The method ( 200 ) of claim 1 , wherein determining ( 225 ) the torque demand or determining ( 230 , 235 ) terminates when the target synchronous speed is reached.

9. A device ( 125 ) for open-loop control of a gearbox ( 100 ) that includes an input shaft ( 105 ), a first proportionally controllable shift element (A to F), and a second proportionally controllable shift element (A to F), the device ( 125 ) comprises:
an interface for connection to one of the first and second shift elements (A to F) or an interface for connection to a drive source which is connected to the input shaft ( 105 );
a processing unit ( 125 ); and
a memory storing computer-executable instructions that, when executed by the processing unit ( 125 ), cause the processing unit ( 125 ) to perform operations comprising
determining a specified differential speed profile that is a profile of a difference between a rotational speed of the input shaft ( 105 ) and a synchronous speed of a gear ratio to be engaged;
determining a torque demand of the drive source or determining a control profile for one of the first and second shift elements (A to F) to be engaged in the gear ratio on the basis of the specified differential speed profile; and
synchronizing the gearbox ( 100 ) based at least in part on one or both of the determined torque demand of the drive source and the determined control profile for the one of the first and second shift elements (A to F) to be engaged.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Stehle Harald
• Schiele Peter
• Maier Günther

Classifications

• F16H61/0403 Primary

  Synchronisation before shifting · CPC title

• F16H59/46

  dependent on a comparison between speeds · CPC title

• F16H59/42

  Input shaft speed · CPC title

• F16H61/686

  with orbital gears · CPC title

• F16H2061/0474

  by smoothing engagement or release of positive clutches; Methods or means for shock free engagement of dog clutches · CPC title