Transmission control system

Patent metadata

Field	Value
Publication number	US-10605355-B2
Application number	US-201916250108-A
Country	US
Kind code	B2
Filing date	Jan 17, 2019
Priority date	Jan 18, 2018
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

A method (200) for the open-loop control of a gearbox (100) that comprises an input shaft (105) and a first and a second proportionally controllable shift element (A-F) is provided. The method includes disengaging (215) the first shift element (A-F) according to a first control profile and engaging (220) the second shift element (A-F) according to a second control profile. The method also includes cyclically performing the following during the disengagement and the engagement: determining (230) a difference between the rotational speed of the input shaft (105) and a rotational speed which the input shaft (105) assumes when the second shift element (A-F) has been completely engaged; determining (230) a gradient of the difference; and adapting (230) the first control profile on the basis of the gradient.

First claim

The invention claimed is:

1. A method ( 200 ) for the open-loop control of a gearbox ( 100 ) that includes an input shaft ( 105 ), a first proportionally controllable shift element (A-F) and a second proportionally controllable shift element (A-F), the method ( 200 ) comprising:
disengaging ( 215 ) the first shift element (A-F) of the gearbox ( 100 ) according to a first control profile;
engaging ( 220 ) the second shift element (A-F) of the gearbox ( 100 ) according to a second control profile; and
cyclically performing the following during the disengagement of the first shift element (A-F) and the engagement of the second shift element (A-F),
determining ( 230 ) a difference between the rotational speed of the input shaft ( 105 ) and a rotational speed which the input shaft assumes when the second shift element (A-F) has been completely engaged,
determining ( 230 ) a gradient of the difference, and
adapting ( 230 ) the first control profile on the basis of the gradient.

2. The method ( 200 ) of claim 1 , wherein adapting ( 230 ) the first control profile comprises adapting ( 230 ) the first control profile on the basis of the gradient when a specification of a slip time of one of the first and second shift elements (A-F) changes.

3. The method ( 200 ) of claim 1 , further comprising suspending the determination ( 230 ) of the difference when the gradient has not been reached at a predetermined point in a gear ratio change.

4. The method ( 200 ) of claim 1 , further comprising determining a deviation from a specified slip time when a slip time deviates from the specified slip time by more than a predetermined amount.

5. A device ( 125 ) for open-loop control of a gearbox ( 100 ) that includes an input shaft ( 105 ), a first proportionally controllable shift element (A-F) and a second proportionally controllable shift element (A-F), the device ( 125 ) comprising:
a first interface for connection to the first shift element (A-F);
a second interface for connection to the second shift element (A-F);
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
disengaging the first shift element (A-F) of the gearbox ( 100 ) according to a first control profile,
engaging the second shift element (A-F) of the gearbox ( 100 ) according to a second control profile, and
cyclically performing the following during the disengagement of the first shift element (A-F) and the engagement of the second shift element (A-F),
determining ( 230 ) a difference between a rotational speed of the input shaft ( 105 ) and a rotational speed which the input shaft ( 105 ) assumes when the second shift element (A-F) has been completely engaged,
determining ( 230 ) a gradient of the difference, and
adapting ( 230 ) the first control profile on the basis of the gradient.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Stehle Harald
• Schiele Peter
• Maier Günther

Classifications

• F16H2200/0065

  the gear ratios comprising nine forward speeds · CPC title

• F16H2200/2064

  using at least one positive clutch, e.g. dog clutch · CPC title

• F16H3/66

  composed of a number of gear trains without drive passing from one train to another · CPC title

• F16H59/42

  Input shaft speed · CPC title

• F16H61/0437 Primary

  by using electrical signals (F16H61/0403 and F16H61/061 take precedence) · CPC title