Optimization of switching operations

Patent metadata

Field	Value
Publication number	US-9897200-B2
Application number	US-201615223000-A
Country	US
Kind code	B2
Filing date	Jul 29, 2016
Priority date	Jul 30, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A method of optimizing shifting of a shifting element which fixes a shaft to another component of the drive-train. Three shifting processes are influenced by respective characteristic forms of a control parameter. The first and second characteristic forms are different from one another. Each shifting process has a distinct start and end time (t Beginn , t Ende ). The rotational speed of the shaft is a function n(t) of time t. An idealized rotational speed n ideal (t):=G{n(t)} is determined by a filter G. First and second evaluation indexes I:=I(t−Δ t ,t)/I (t Beginn − t , t Beginn ) are calculated, in which t Beginn <t≦t Ende . I(t a , t b ) is a measure of a deviation of the rotational speed n(t) from the idealized rotational speed n ideal (t) over time [t a ,t b ]. The third characteristic form is chosen based on the first and second evaluation indexes I.

First claim

The invention claimed is:

1. A method of optimizing shifting processes of a shifting element, the shifting element is designed to connect a shaft of a drive-train with another component of the drive-train in a rotationally fixed manner, a first shifting process is influenced by a first manifestation of a control parameter, a second shifting process is influenced by a second manifestation of the control parameter and a third shifting process is influenced by a third manifestation of the control parameter;
the first manifestation and the second manifestation of the control parameter are different from one another;
the first shifting process is initiated at a first begin time t 1, Beginn and is completed at a first end time t 1, Ende ;
the second shifting process is initiated at a second begin time t 2, Beginn and is completed at a second end time t 2, Ende ; and
a rotational speed function n(t) describes a rotational speed of the shaft as a function of time t; and the method comprising:
determining an idealized rotational speed n ideal (t):=G{n(t)} by applying a smoothing function (G) to the rotational speed;
calculating a first evaluation index I 1 =I(t−Δ t ,t)/I(t 1, Beginn −Δ t , t 1, Beginn ), in which:
t 1, Beginn <t≦t 1, Ende ;

calculating a second evaluation index I 2 :=I(t−Δ t ,t)/I(t 2, Beginn −Δ t , t 2, Beginn ), in which:
t 2, Beginn <t≦t 2, Ende ;

defining a rotational speed deviation I(t a , t b ) as a measure of a deviation of the rotational speed n(t) from the idealized rotational speed n ideal (t) over a time interval [t a ,t b ]; and
selecting the third manifestation of the control parameter as a function of the first evaluation index I 1 and the second evaluation index I 2 .

2. The method according to claim 1 , further comprising:
selecting the third manifestation of the control parameter such that third manifestation corresponds to the first manifestation, if the first evaluation index I 1 <the second evaluation index I 2 ; and
selecting the third manifestation of the control parameter such that the third manifestation corresponds to the second manifestation, if the second evaluation index I 2 <the first evaluation index I 1 .

3. The method according to claim 1 , further comprising:
actuating the shifting element hydraulically; and
defining the control parameter as a rapid filling time.

4. The method according to claim 1 , further comprising:
defining the smoothing function (G) as a frequency filter.

5. The method according to claim 1 , further comprising applying the smoothing function (G) to the rotational speed to filter at least one natural frequency of the drive-train.

6. The method according to claim 1 , further comprising calculating the rotational speed deviation:
I(t a ,t b ) as a function of ∫ t a t b |n(t)−n ideal (t)|dt.

7. The method according to claim 6 , wherein the following relationship applies to the rotational speed deviation:
I ( t a ,t b )=∫ t a t b |n ( t )− n ideal ( t )| dt×Z.

8. The method according to claim 1 , wherein the following relationship applies to the rotational speed deviation:
I ( t a ,t b )=∫ t a t b |n ( t )− n ideal ( t )| dt.

9. The method according to claim 1 , further comprising calculating the rotational speed deviation
I(t a ,t b ) as a function of a number Z of zero-points of n(t)−n ideal (t) during the time interval ([t a , t b ]).

10. The method according to claim 1 , further comprising calculating the rotational speed deviation
I(t a , t b ) as a function of at least one of a first derivative and a second derivative of a differential of the rotational seed and the idealized rotational speed over time.

11. A method of optimizing shifting processes of a shifting element, the shifting element connects a shaft of a drive-train with another component of the drive-train in a rotationally fixed manner, a first shifting process is influenced by a first manifestation of a control parameter, a second shifting process is influenced by a second manifestation of the control parameter and a third shifting process is influenced by a third manifestation of the control parameter, the method comprising:
defining the first manifestation of the control parameter as being different than the second manifestation of the control parameter;
initiating the first shifting process at a first time point t 1, Beginn and completing the first shifting process at a second time point t 1, Ende ;
initiating the second shifting process at a third time point t 1,Beginn and completing the second shifting process at a fourth time point t 1, Ende ;
defining a rotational speed of the shaft as a function n(t) of time t;
determining an idealized rotational speed of the shaft n ideal (t):=G{n(t)} by applying a smoothing function G to the rotational seed;
calculating a first evaluation index: I 1 =I(t−Δ t ,t)/I(t 1, Beginn −Δ t , t 1, Beginn ), in which:
t 1, Beginn <t≦t 1, Ende ;

calculating a second evaluation index I 2 :=I(t−Δ t ,t)/I(t 2, Beginn −Δ t , t 2, Beginn ), in which:
t 2, Beginn <t≦t 2, Ende ;

defining a rotational speed variation I(t a , t b ) as a measure of a deviation of the rotational speed of the shaft n(t) from the idealized rotational speed of the shaft n ideal (t) over a time interval [t a ,t b ]; and
selecting the third manifestation of the control parameter as a function of the first evaluation index I 1 and the second evaluation index.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Szabo Tomas

Classifications

• F16H59/38

  of gearing elements · CPC title

• F16H2061/0087

  Adaptive control, e.g. the control parameters adapted by learning · CPC title

• F16H61/0403 Primary

  Synchronisation before shifting · CPC title