Zf Friedrichshafen Ag

Daniel Zerlaut

Martina Jehle

Christian Pannek

Andreas Schmidt

Angelique Schwimmer

A method for determining an actuating-travel range between two shift-element halves of a form-locking shift element (A, F) during an engagement of the shift element (A, F) and in the presence of a tooth-on-tooth position between the two shift-element halves is provided. An actuating movement of the at least one movable shift-element half with respect to the other shift-element half is monitored by a sensor. A tooth-on-tooth position is detected when it is determined, by the sensor, within an actuating-travel range of the at least one movable shift-element half between a disengaged condition and an engaged condition of the shift element, that the actuating movement of the movable shift-element half in the engagement direction is zero. A ratio between an engagement force applied at the shift element and a radial force acting on the shift-element halves is within a value range, which facilitates a tooth-on-tooth position and an actuating movement of the shift-element half in the engagement direction is detected by the sensor after the reduction of the engagement force and/or after an increase of the applied torque.

Method and control unit for determining the travel range between two gear shift element halves of an interlocking gear shift element

A method for monitoring a signal of a sensor is provided. With the aid of the sensor, a current actuating-travel position of at least one movable shift-element half of a form-locking shift element (A, F) of a transmission () is detected during a disengagement or an engagement of the shift element (A, F). A malfunction of the sensor is detected when the current actuating-travel position of the movable shift-element half is located outside the actuating-travel range defined by the end positions and is spaced apart from the first end position or from the second end position by an extent greater than a threshold value. Additionally, it is determined, during a subsequent actuation of the shift element (A, F), depending on rotational speeds of components of the transmission (), whether the movable shift-element half is located in a demanded end position.

Method and control unit for monitoring a signal of a sensor

A method for operating a transmission () is provided, which includes a hydraulic pump drivable on a transmission-input end and at least one form-locking shift element (A, F). One of the shift-element halves is displaceable between a first end position and a second end position with a hydraulic pressure of the hydraulic pump. The current position of the shift-element half is detected with a sensor and is stored as a specified end-position value if the shift-element half is located in one of the end positions, the hydraulic pump is driven, and the shift-element half is actuated, with the hydraulic pressure, towards the current end position. When the hydraulic pressure is less than a threshold value, a deviation is determined between the current position of the shift-element half and the specified end-position value. The hydraulic pressure is increased when the deviation is greater than a threshold value.

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Tettnang, Germany

Daniel Zerlaut