# US 8,788,168 B2 · Method for controlling a dual clutch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,168 B2 - Document ID: US8788168B2 - Status: Granted - Kind: B2 - Application number: 13/633,416 - Filed: 2012-10-02 - Published: 2013-01-31 - Granted: 2014-07-22 - Earliest claimed: 2010-04-08 - Assignees: Schaeffler Technologies AG & Co. KG - Applicants: Schaeffler Technologies AG & Co. KG - Inventors: Markus Baehr - Web page: https://patentgrep.com/patent/US8788168B2 ## CPC - F16D 48/066: {Control of fluid pressure, e.g. using an accumulator (F16D48/062, F16D48/068 take precedence)} - F16D 2500/1086: Concentric shafts - F16D 2500/3024: Pressure - F16D 2500/3026: Stroke - F16D 2500/50236: Adaptations of the clutch characteristics, e.g. curve clutch capacity torque - clutch actuator displacement - F16D 2500/7041: Position - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract The invention relates to a method for controlling a dual clutch and a dual clutch housing two friction clutches which are each actuated independently of one another by means of a hydrostatic actuator. The hydrostatic actuator actuates the clutch as a function of a control signal of a control unit by means of a pressure which is applied to the actuation element and corresponds to a position of an actuation element of the friction clutch along an activation path. In order to sense a change in the position of the actuation element on one friction clutch which is brought about by the pressure on the actuation element of the other friction clutch, it is proposed to determine a correction variation for the purpose of compensating the changed position by means of a variable which represents the pressure of the disruptive hydrostatic actuator. ## Claims ### Claim 1 A method for controlling a friction clutch having two friction clutches that can be actuated by one hydrostatic actuator each, comprising: depending on a control signal of a control unit, exerting a pressure on the actuating element corresponding to a position of an actuating element of the friction clutch along an actuating travel path; changing the pressure on an actuating element of one friction clutch according to the position of the actuating element on the other friction clutch at least partially; and, obtaining, using the control unit, a correction value, representing the pressure of the disrupting hydrostatic actuator to compensate for the changed position. ### Claim 2 (depends on 1) The method as recited in claim 1, further comprising: compensating for, using the control unit and the correction value, the position of the disrupted actuating element in such a way that the undisrupted position is at least approximately restored again. ### Claim 3 (depends on 1) The method as recited in claim 1, wherein the representative value is a pressure signal of the pressure sensor of the disrupting hydrostatic actuator. ### Claim 4 (depends on 1) The method as recited in claim 1, wherein the representative value is at least one signal of at least one component of the dual clutch elastically deformed by the pressure of the hydrostatic actuators. ### Claim 5 (depends on 1) The method as recited in claim 1, further comprising: producing, using the control unit, a proportional connection between the correction value and the representative value. ### Claim 6 (depends on 5) The method as recited in claim 5, further comprising: determining, using the control unit, a proportionality constant empirically for the employed dual clutch. ### Claim 7 (depends on 5) The method as recited in claim 5, further comprising: applying, using the control unit, a discrete proportionality constant for each of the friction clutches. ### Claim 8 (depends on 1) The method as recited in claim 1, wherein the correction value has a predefinable offset applied to it. ### Claim 9 (depends on 8) The method as recited in claim 8, further comprising: determining, using the control unit, the offset empirically; and applying, using the control unit, the offset separately for each of the friction clutches. ### Claim 10 (depends on 1) A dual clutch having two friction clutches, each actuated by a hydrostatic actuator having a pressure sensor, to carry out the method as recited in claim 1. ### Claim 11 A method for controlling a friction clutch including first and second friction clutches with first and second hydrostatic actuators and first and second actuating elements, respectively, comprising: exerting, with the first hydrostatic actuator and depending on a control signal of a control unit, a pressure on the first actuating element corresponding to a position of an the actuating element along an actuating travel path; changing, in response to the pressure, a position of the second actuating element from an undisrupted position to a disrupted position; obtaining, using the control unit, a correction value, representing the pressure, to compensate for the disrupted position of the second actuating element; and, restoring, using the control unit and of the correction value, the second actuator element to approximately the undisrupted position. ### Claim 12 A method for controlling a friction clutch including a first friction clutch with a first hydrostatic actuator having a pressure sensor, and a first actuating element and a second friction clutch including a second hydrostatic actuator and second actuating element, respectively, comprising: exerting, with the first hydrostatic actuator and depending on a control signal of a control unit, a pressure on the first actuating element corresponding to a position of an the actuating element along an actuating travel path; changing, using the control unit and in response to the pressure, a position of the second actuating element from an undisrupted position to a disrupted position; and, obtaining, using the control unit and from a pressure signal of the pressure sensor, a correction value, representing the pressure, to compensate for the disrupted position.