Method for determining a control force of an actuator

Patent metadata

Field	Value
Publication number	US-9964129-B2
Application number	US-201514863632-A
Country	US
Kind code	B2
Filing date	Sep 24, 2015
Priority date	Sep 26, 2014
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A method for determining an operating force (F p ) of a positioning actuator ( 3 ), whose adjustment movements are produced by virtue of an appropriate supply of a working medium via actuating at least one valve ( 4 to 7 ) associated with the positioning actuator ( 3 ). The operating force (F p ) is determined by computational determination. To be able to carry out the computational determination of the operating force (F p ) with little effort, by the at least one valve ( 4 to 7 ) in each case, a respective, essentially constant mass flow ({dot over (m)} iv , {dot over (m)} ov ) of working medium is maintained either into the positioning actuator ( 3 ) and/or out of the positioning actuator ( 3 ).

First claim

The invention claimed is:

1. A method of determining an operating force (F p ) of a positioning actuator ( 3 ), whose adjustment movement is produced by a supply of a working medium by actuation of first and second valves which communicates with the positioning actuator ( 3 ), the method comprising:
producing an essentially constant mass flow ({dot over (m)} iv , {dot over (m)} ov ) of the working medium by the first and the second valves either:
into the positioning actuator ( 3 ), or
out of the positioning actuator ( 3 ) thus reducing an influence of non-linear factors; on the operating force

determining the operating force (F p ) using computation performed, via a control unit, during operation of a motor vehicle clutch;
creating a characteristic curve using a polynomial; and
comparing the operating force (F p ) to the characteristic curve, via the control unit, to determine a wear condition the motor vehicle clutch.

2. The method according to claim 1 , further comprising actuating the motor vehicle clutch ( 1 ) using the positioning actuator ( 3 ) in such manner that the operating force (F p ) of the positioning actuator ( 3 ) represents a release force of the motor vehicle clutch ( 1 ).

3. The method according to claim 2 , further comprising creating the characteristic curve of the release force by varying the operating force (F p (t)) and taking into account respective clutch positions (z(t)) of the motor vehicle clutch ( 1 ).

4. The method according to claim 3 , further comprising, after creation of the characteristic curve of the release force, determining, via the control unit, parameters for regulation of the motor vehicle clutch ( 1 ) by a gain-scheduling method.

5. The method according to claim 2 , further comprising keeping an incoming mass flow ({dot over (m)} iv ) essentially constant via the first valve ( 4 , 5 ).

6. The method according to claim 2 , further comprising keeping an outgoing mass flow ({dot over (m)} ov ) essentially constant via the second valve ( 6 , 7 ).

7. The method according to claim 1 , further comprising controlling the first and the second valves with a low frequency, in a range 5 to 20 Hz, to set the essentially constant incoming mass flow ({dot over (m)} iv ) and the essentially constant outgoing mass flow ({dot over (m)} ov ).

8. An actuating mechanism ( 2 ) for a motor vehicle clutch ( 1 ) comprising a positioning actuator ( 3 ) whose adjustment movement is produced by a supply of compressed air by actuation of first and second valves that communicates with the positioning actuator ( 3 ), and an operating force (Fp) of the positioning actuator ( 3 ) being determined by a method comprising:
producing an essentially constant mass flow ({dot over (m)} iv , {dot over (m)} ov )of the compressed air by the first and second valves either:
into the positioning actuator ( 3 ), or
out of the positioning actuator ( 3 ) thus reducing an influence of non-linear factors; on the operating force

determining the operating force (F p )using computation performed, via a control unit, during operation of the motor vehicle clutch;
creating a characteristic curve using a polynomial and
comparing the operating force (F p ) to the characteristic curve, via the control unit, to determine a wear condition the motor vehicle clutch.

9. The actuating mechanism ( 2 ) according to claim 8 , further comprising a computer program product for determining the actuating force (Fp) of the positioning actuator ( 3 ), the computer program product issuing corresponding commands, stored in a software module on the control unit, for setting the respective essentially constant mass flow ({dot over (m)} iv , {dot over (m)} ov ) of the compressed air into the positioning actuator ( 3 ) and out of the positioning actuator ( 3 ), and determining the operating force (Fp) of the positioning actuator ( 3 ) using the following formula for disengaging the vehicle clutch:

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Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Chamaken Kamde Alain Tierry
• Moser Wilhelm

Classifications

• F15B2211/3138

  the positions being discrete · CPC title

• F16D2500/70605

  Adaptive correction; Modifying control system parameters, e.g. gains, constants, look-up tables · CPC title

• G05B1/00

  Comparing elements, i.e. elements for effecting comparison directly or indirectly between a desired value and existing or anticipated values · CPC title

• F15B2211/30575

  in a Wheatstone Bridge arrangement (also half bridges) · CPC title

• F16D2500/70404

  Force · CPC title