Zf Friedrichshafen Ag

Georg Mihatsch

Jorg Arnold

Valentine Herbeth

Andreas Schmidt

Thilo Schmidt

Klaus Steinhauser

Ruben Cueppers

Jörg Arnold

Max Trautwein

Gabor Diosi

Christoph Margraf

Jens Weller

Thorsten Schaetzle

Patrick Riedel

Joerg Arnold

A method for operating an automatic transmission includes shifting the automatic transmission to a substitute gear if, after adjusting a first one of at least one positive-locking shift element towards a closed configuration, the first one of the at least one positive-locking shift element occupies an intermediate position. The first one of the at least one positive-locking shift element does not participate in the transmission of power in the substitute gear. A related transmission control device for an automatic transmission is also provided.

Method and control device for operating an automatic transmission

A method for operating an automatic transmission is provided. The method includes initiating a synchronization of a positive shifting element of the automatic transmission while the automatic transmission is operating at less than a threshold output speed. The method also includes closing a first non-positive shifting element of the automatic transmission and positioning a second non-positive shifting element of the automatic transmission at an engaged configuration of the second non-positive shifting element during the synchronization of the first positive shifting element in order to synchronize the first positive shifting element.

Method for operating an automatic transmission

A method of engaging a form-interlocking shifting element to obtain a gear in an automatic transmission in which at least one further, frictional shifting element is involved in obtaining the gear to be engaged and a shifting element, not involved in obtaining the gear to be engaged but which serves as a synchronizing shifting element, is actuated in order to synchronize the interlocking shifting element to be engaged. The further, frictional shifting element, involved in engaging the gear, is engaged and then disengaged, to a defined extent, to bring the frictional shifting element to a slipping condition, in order to ensure the engagement of the interlocking shifting element.

Procedure for engaging a form-locking shift element to realize a gear in an automatic transmission, whereat at least one further friction shift element is to be engaged to realize the gear to be activated

A method for operating a 9-speed transmission which changes operating states by actuating shift elements. At least one of the shift elements is a form-locking shift element, which disengages to implement a defined transmission operating state during which the power flow, between transmission input and output shafts, is present or interrupted. A sensor is associated with the locking shift element. An operating state of the locking shift element can be determined by the sensor. Upon a request to disengage the locking shift element, a disengagement control signal is generated and the locking shift element is actuated in the disengagement direction, depending on the disengagement control signal. The transmission is shifted to a safe operating state, in which at least the transmission output shaft can rotate, when an engaged operating state of the locking shift element is determined by the sensor even though a disengagement control signal was generated.

Procedure for operating a transmission device, particularly a 9-speed-transmission

A method for operating a transmission device, which is transferable into different operating states through the actuation of shifting elements, is described. At least one of the shifting elements is designed as a positive-locking shifting element, which is supplied with operating pressure for presenting a defined operating state of the transmission device. Through a sensor device upstream of a valve device, which is connected to a transmission area essentially featuring ambient pressure, a value of a pressure signal corresponding to the operating pressure can be determined. Upon exceeding a threshold value of the pressure signal, currently in the area of the positive-locking shifting element, a change in operating state is determined, and, upon falling short of an additional threshold value of the pressure signal, the reaching of the requested operating state is established. In a non-actuated operating state of the positive-locking shifting element, the pressure in the transmission area is established by the sensor device. Upon the presence of a request for a change in operating state in the area of the positive-locking shifting element, the threshold value and the additional threshold value are determined from the sum of the pressure calculated in the transmission area prior to the presence of the request for the change in operating state and a pressure offset value.

Method for operating a transmission device

A method for detecting a malfunctioning shift element in an automatic transmission is provided. The method includes operating the automatic transmission in an intermediate gear. A selected shift element of the automatic transmission is commanded to a disengaged configuration in the intermediate gear. The method also includes measuring a gear ratio of the automatic transmission while the automatic transmission is operating in the intermediate gear, and determining whether the selected shift element of the automatic transmission is malfunctioning based at least in part on the gear ratio of the automatic transmission in the intermediate gear.

Method for detecting a nonoperational shift element in an automatic transmission

A method of operating a vehicle drive-train comprising an internal combustion engine and a transmission system functionally connected to the internal combustion engine. The transmission has an interlocking shifting element, one shifting element half of which is functionally connected to the transmission input shaft while the other shifting element half is functionally connected to a transmission output shaft. Upon receipt of a command to change the transmission from a neutral position, in which a force flow through the transmission is interrupted, to an operating condition, in which the force flow through the transmission is produced, the interlocking shifting element is changed to an engaged operating condition. A speed difference between the shifting element halves is brought by varying the speed of the internal combustion engine into a speed difference window within which the interlocking shifting element can be changed to its engaged operating condition.

Method for operating a vehicle drive train having an internal combustion engine

A method for recording an initial position of at least one positive-locking shifting element of a transmission of a vehicle is proposed, whereas an initial position of the shifting element is determined and assigned depending on a recorded operating pressure curve for the actuation of the shifting element.

Method for detecting the origin position of a shift element

A method of operating a transmission device. At least one of the shift elements is a form-locking shift element. A sensor is associated with the form-locking shift element which can determine an operating state of the form-locking shift element. When a request to disengage the form-locking shift element occurs, a disengagement control signal is generated and the form-locking shift element is actuated in the direction of disengagement, depending on the disengagement control signal. The transmission device is transferred to a safe operating state in which the transmission output shaft can rotate, when an actuating pressure that changes the operating state of the form-locking shift element is determined with the sensor, even though a disengagement control signal was not generated, and/or when the sensor is associated with at least two form-locking shift elements and the form-locking shift elements are subjected to actuating pressure to implement a requested operating state change.

A method of shifting a vehicle drive-train transmission having frictional and interlocking shifting elements which are engageable to obtain various gears. When shifting from a current gear to a target gear, in which the interlocking shifting element is engaged, if after the shift starts it becomes necessary to engage the current gear in the transmission while engaging the interlocking shifting element, a current operating condition of the interlocking shifting element is determined. If the current operating condition of the interlocking shifting element indicates that engagement can be interrupted and the interlocking shifting element can be disengaged, the interlocking shifting element is disengaged. If the current operating condition of the interlocking shifting element indicates that engagement of the interlocking shifting element has to be carried out and the interlocking shifting element engaged, then the interlocking shifting element is engaged and/or the force flow in the transmission device is interrupted.

Method for the operation of a transmission device in a vehicle drive train

A method of operating a transmission of a vehicle drive-train when a gearshift from a current gear toward a target gear has been requested. The transmission having frictional shifting elements and at least one interlocking shifting element. If an actuating electrical current, equivalent to a closed operating condition of the frictional shifting element to be engaged, and an actuating electrical current, equivalent to an open operating condition of the interlocking shifting element to be disengaged, are determined while, at the same time, a closed operating condition of the interlocking shifting element to be disengaged is detected by a sensor, a fault is recognized. If the fault is recognized during a predefined test period, one or more selected shifting elements are disengaged and a force flow in the transmission is interrupted. Alternatively, by disengaging the frictional shifting element to be engaged, the current gear is engaged in the transmission.

Method for the operation of a transmission device in a vehicle drive train when a request is made to change gears

When a request is made to change gears, the form-fitting shifting element being disengaged, for the requested gear change, is disengaged at a predefined target disengagement moment following the target disengagement moment. When the gear is actually changed, an actual disengagement moment is determined based on when the form-fitting shifting element begins disengaging and a transmission operating state variable. If there is a deviation between the actual moment and the target moment of disengagement, then the target disengagement moment is modified by a time value, and the moment when the form-fitting shifting element begins to be actuated is shifted in time in relation to the target moment of disengagement and/or actuation of the shifting element to be connected is adjusted to a determined characteristic of the operating state of the form-fitting shifting element to be disconnected such that it is disengaged approximately at the target disengagement moment.

Method for the operation of a transmission device in a vehicle drive train, comprising at least one form-fitting shifting element and multiple frictionally engaged shifting elements

A method of operating a transmission device () having a plurality of frictionally engaging shift elements (B, C, D and E) and at least one form-locking shift element (A, F) for implementing different transmission ratios. Upon a requested change in operating state of the transmission device (), the at least one form-locking shift element (A) is transferred into an at least nearly load-free state, during which the form-locking shift element (A) is transferred from an engaged to a disengaged operating state by increasing the transfer capability of at least one frictionally engaging shift element (E), which is not engaged in the power flow of the transmission device () either to represent the present operating state or to represent the requested operating state.

Method for operating a transmission device having a plurality of friction-fit shift elements and at least one form-fit shift element

A method of operating a transmission device comprising friction-locking and form-locking shift elements for obtaining different gear ratios. A shift request for engaging a shift element undergoes a time delay dependent upon an operating state prior to a time of engagement of the shift element. A rotational speed differential between halves of the shift element lies within a rotational speed differential window required for the engagement procedure is assigned to the time of engagement. A gradient of the transmission input speed is ascertained at the time of the shift request, and the actual gradient is subsequently monitored and compared with the gradient that existed at the time of the shift request. If an absolute deviation greater than a threshold value is ascertained, the time delay is changed or an actuation of another shift element to be disengaged is varied such that the deviation is reduced below the threshold value.

Method for operating a transmission device with a plurality of friction-locking and positive-locking shifting elements

A method of operating a vehicle drive train having a drive machine, a transmission apparatus having a plurality of shift elements and an output drive. The plurality of shift elements are engaged or disengaged in a power flow for achieving different transmission ratios within the transmission apparatus. The output drive is coupled to a transmission output shaft and the drive machine is coupled to a transmission input shaft of the transmission apparatus. Upon a request to interrupt power flow within the transmission apparatus, between the transmission input shaft and the transmission output shaft, a maximum number of shift elements are transferred to and/or held in an engaged operating state, and the remaining portion of the shift elements are transferred to and/or held in a disengaged operating state with the transmission output shaft being rotatable.

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Lindau, Germany

Georg Mihatsch