Abstract: A method of determining a fill current value of at least one frictionally engaging shift element of an automatic transmission. The automatic transmission includes a hydrodynamic converter at which a speed ratio arises and an output shaft. In a control sequence, with a stationary output shaft, the speed ratio is influenced by changing a control current, and the fill current value is determined from the progression of the speed ratio arising during the control sequence, in conjunction with the progression of the control current.

Abstract: 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.

Abstract: A method of operating a vehicle drive-train with an engine and a transmission during a gearshift in which an interlocking shift element is disengaged and a frictional shift element is engaged. Upon a shift command, the shifting time and a transmission input speed are monitored. If the input speed deviates from a synchronous speed equivalent to the gear ratio being disengaged, recognizing disengagement of the interlocking shifting element. If an engaged operating condition of the interlocking shifting element to be disengaged is detected, after the lapse of a time interval beginning with the shift command, a current drive torque of the drive machine is brought by motor actuation to a level that corresponds to a difference between the current transmission input torque and a torque that can be transmitted by the frictional shifting element to be engaged, operating with slip, plus a torque offset value.

Abstract: A method of operating a transmission (1) with at least one interlocking shift element (F) having at least two shift element halves that can be brought into interlocked engagement with one another. When a command is received to close the interlocking shift element (F), a current rotational speed difference between the shift element halves of the interlocking shift element (F) and the current positions of the shift element halves are determined. If the rotational speed difference is smaller than a first speed difference threshold value and if a tooth-on-tooth position has occurred at the interlocking shift element (F), then to release the tooth-on-tooth position, the actuation force is changed to a release level at which a rotational speed difference above a second speed difference threshold value is produced between the shift element halves.

Abstract: A method of operating a transmission of a vehicle drive train with at least one drive machine. The transmission is formed with at least one interlocking shift element and a plurality of frictional shift elements in order to obtain various gear ratios. During an engaging process of the interlocking shift element, starting from a disengaged operating condition, in which halves of the interlocking shift element are out of engagement, to an engaged operating condition, in which the shift element halves are interlocked in a rotationally fixed manner, when interlock between the shift element halves is obstructed, a rotational speed difference is produced at least temporarily between the shift element halves, at which the interlock in the area of the interlocking shift element can be engaged. To produce the speed difference between the shift element halves, the transmission capacity of at least one frictional shift element is increased.

Abstract: A method is described for the operation of a transmission device (1) with a plurality of frictional shift elements (A, D, E, F) and at least one interlocking shift element (B, C) for obtaining various gear ratios. When a command is received for a gearshift during which the interlocking shift element (C) has to be changed from an open to a closed operating condition, the interlocking shift element (C) is at least approximately synchronized by increasing the transmission capacity of at least one frictional shift element (A) which does not have to be engaged in the force flow either to obtain the gear ratio that is to be disengaged or to obtain the gear ratio that is to be engaged.

Abstract: A method is described for operating a vehicle drive train (1) with a drive machine (2) and with a transmission device (3) during a coast upshift, during which at least one interlocking shift element (6) that is engaged in the force flow of the transmission device (3) to produce the gear ratio to be disengaged is disengaged from the force flow and also frictional shift element (5) that has to be engaged in the force flow of the transmission device (3) to obtain the gear ratio to be engaged is engaged in the force flow. According to the invention, when a shift command is given for a gear ratio change, a torque applied at the interlocking shift element (6) to be disengaged is reduced at least approximately to zero by a defined engine intervention and the interlocking shift element (6) is then disengaged from the force flow of the transmission device (3).

Abstract: A method for operating a vehicle drivetrain (1) having a drive motor (9), a transmission (10) and a drive output (2). When a gear ratio change is called for in the transmission (10), between an actually engaged gear and a target gear, one of a frictional or an interlock-type shift element is engaged in a flow of force in the vehicle drivetrain (1) and the other of an interlock-type or a frictional shift element is disengaged from the flow of force in the vehicle drivetrain (1). An actual speed that is at least equivalent to a transmission input speed is monitored and an actuation pressure of the frictional shift element involved in the shift operation and/or a torque of the drive motor (9) is/are varied to change the actual speed to a nominal speed.

Abstract: A transmission apparatus (10) having at least one form-lock shifting element (12) that can be actuated by a hydraulic system (11) which, in the region of a piston chamber, can be subjected to hydraulic pressure (p—12) via a hydraulic fluid-conducting feed line (20) and which can be actuated from a disengaged to an engaged operating state. The hydraulic fluid-conducting feed line (20) of the shifting element (12) is effectively connected to a damping device (22) by which pressure fluctuations, of the hydraulic pressure (p—12) in the feed line (20), can be at least partially compensated.

Abstract: A transmission device (10) having at least one form-fitting shifting element (12) which is hydraulically actuated via a hydraulic system (11) with hydraulic pressure (p—12), in the area of a piston chamber, via a feed line (20) that conveys hydraulic fluid, to shift from a disengaged to and engaged operating state. A non-return valve device (27) is arranged upstream of the form-fit shifting element (12).