Abstract: A method for determining a torque characteristic of a friction clutch located in a drive train of a motor vehicle in the force flow between a drive engine and a transmission and which is closed in its rest position. At least two marker points of a regulating-path-dependent torque characteristic are determined, one of which is determined at a slipping limit of the clutch. To enhance determination of the torque characteristic, a first marker point is determined with the clutch engaged, the transmission in neutral and the engine running, by slowly disengaging the clutch until a reduction in the speed of the transmission input shaft relative to the engine speed is detected. A corresponding pair of values of this marker point with the known braking torque of the input shaft and the set position are used for adapting an existing characteristic.

Abstract: A method for controlling or regulating a clutch torque of a startup clutch of a motor vehicle, which first of all reliably prevents an unintentional rolling of the motor vehicle down a gradient and second enables a comfortable maneuvering mode, which requires no separate actuation of an operating element for activating a maneuvering mode, and also enables a precisely dosed speed definition during maneuvering on gradients, wherein the adjusted speed is substantially independent from the gradient of the ground and the motor vehicle load. A startup and maneuvering control device is provided according to the invention, which reads in driving resistance data, determines therefrom a driving resistance value, and determines a base value of the clutch torque of the automated startup clutch in dependence thereof, which is adjusted in dependence upon the accelerator pedal.

Abstract: A method for operating a drivetrain comprising an automatic transmission (2) and a power engine (1) such that, in order to carry out a shift operation, in particular an upshift, a clutch (4) connected between the automatic transmission (2) and the power engine is first disengaged and, after carrying out the shift operation, engaged again. A vehicle speed gradient, a transmission input rotational speed gradient, a transmission output rotational speed gradient or a wheel rotational speed gradient is monitored, and after the shift operation has been carried out, the clutch (4) is engaged in such a manner that the gradient being monitored lies within a defined range of values or assumes a defined value.

Abstract: A method of determining and reducing vibrations caused by a clutch (3) in a drivetrain (1) of a motor vehicle, in which the disturbing vibrations are detected by a control and regulating unit aided by suitable sensors and, if predetermined limit values are exceeded, at least one device is actuated by the control and regulating unit in such manner that the disturbing vibrations are completely eliminated or at least reduced in amplitude. At least one torque sensor (8, 9, 10) is used to detect the occurrence of vibrations in the drivetrain (1) and the torque sensor (8, 9, 10) is used to determine vibration amplitude.

Abstract: A method for actuating a clutch (6) of a drivetrain of a motor vehicle such that, when the motor vehicle is rolling downhill with the accelerator pedal not being actuated and when the motor vehicle is coasting on level ground with the accelerator pedal not being actuated, a clutch position of the clutch (6) is determined as a function of a rotational speed difference between an input speed of a transmission (2) of the drivetrain and an idling speed of a power engine (1) of the drivetrain. The method includes the steps of determining the clutch position from the rotational speed difference between the transmission input speed and the power engine idling speed and correcting the clutch position using at least one parameter that depends on acceleration of the motor vehicle.

Abstract: A method and a device for controlling an automatic or automated clutch (4) of a vehicle, by a pressure fluid drive actuator (6) whereby the waypoint of a part (piston rod 12), connected with the drive actuator (6), is captured via a displacement sensor (28) and entered, as a control parameter, into a clutch control interacting with the vehicle control system (26). Provision is made for a diversified redundancy by use of a pressure sensor (30) measuring the fluid pressure in the drive actuator (6). The pressure sensor (30) monitors and stores the pressure in the drive actuator (6) and pressure changes, when engaging or disengaging the clutch, as a curve in the vehicle control system (26). Hereby, the level of engagement of the clutch is represented by the waypoint of drive actuator (6) by the pressure in the drive actuator (6) so that, if there is a malfunction in the displacement sensor (28), an emergency drive function is maintained.

Abstract: A method of monitoring a hydraulic or pneumatic transmission control system, which comprises a pressure supply unit with a conduit directing a pressure medium under a supply pressure, and an actuating member for a clutch control element of a friction clutch. The actuating member has a pressure space which can be connected by a clutch control valve to the conduit, and in which the supply pressure is determined by a pressure sensor that can be connected to the conduit. The method includes the steps of determining the supply pressure by the pressure sensor, given that briefly opening the clutch control valve produces a pressure increase and/or a pressure gradient of the control pressure in the pressure space, and the currently existing supply pressure can be calculated from the control pressure, the pressure increase and/or the pressure gradient.

Abstract: A method of controlling an automated friction clutch arranged in a drivetrain of a motor vehicle in the force flow, between a motor and transmission, and the automated friction clutch is designed to be passively engaged by spring pressure and can be disengaged and engaged by a controllable clutch actuator. The automated friction clutch is provided with a path sensor for detecting the clutch actuator travel such that during the operation of the motor a current key point of a torque characteristic, provided for controlling the friction clutch, is determined and used for adapting the torque characteristic. With the friction clutch engaged and without the clutch actuator exerting any force, several values of the actuator travel are determined at intervals from which a current engagement point, close to the actual engagement point of the torque characteristic, is determined and with which the torque characteristic is adapted.

Abstract: A method of determining the wear condition of a shifting clutch (1) of a motor vehicle which is provided either for interrupting the force flow or equalizing the rotation speed between a drive output shaft (2) of an internal combustion engine (3) and a drivetrain (4). The wear condition of the clutch (1) is determined from the parameters of clutch release path (sausrück) the and release force (Fausrück), at a release bearing (5) of the clutch (1) and, for this purpose, a difference between the clutch release path (sausrück), at a first increase-point (11; 12) of the release force (Fausrück) and at a reference point (13) represented by a second increase of the release force (Fausrück), is measured when the clutch is actuated.

Abstract: A clutch system for producing and interrupting a force flow between the engine and transmission of a motor vehicle, with a clutch, which is disengaged unless actuated, and one or more valves, which regulate the flow of pressure medium and which are electrically actuated by a control and regulation unit. If there is electrical failure while driving and when a gear is engaged or when the vehicle is stationary, the engine is running and a transmission gear is engaged, unintended clutch engagement is prevented. The valves are designed such that if there is a failure of the voltage supply and consequently also of the actuation of the valves by the electronic control and regulation system, the operating condition of the clutch existing at the time of failure, namely the disengaged or engaged operating condition, remains as it is.

Abstract: A method for establishing malfunctions of components of a motor vehicle power train as well as the reaction to the same. The power train has a drive motor and an automatic transmission with respectively allocated control devices, setting apparatus and sensors, and the transmission input shaft is allocated a torque sensor for recording the transmission input shaft. During operation of the motor vehicle, the functions of the control devices, the operating elements, the sensors and their data transmission apparatus as well as the measured values of the transmission input torque are recorded and checked for signs of malfunction. After recognizing such a malfunction, operations are conducted by means of which the motor vehicle can be further operated in an emergency type of operation or with the aid of which the driving operation can be safely ended.

Abstract: A method of controlling an automated friction clutch in a drivetrain of a motor vehicle between a drive motor and a manual transmission. During clutch actuation, at least one operating parameter of the friction clutch is detected by a sensor and from variation of the operating parameter at least one adaptation parameter is derived for correcting a control parameter of the associated clutch control element. To obtain information about variation of the clutch release force and to improve the control of an associated clutch control element, the friction clutch is fully disengaged with constant control or actuation of the clutch control element. During the disengagement process, the release travel path is determined as a function of release time, and from the time variation of the release travel path, a characteristic value is determined which is used to determine an adaptation parameter for correcting the control parameter of the clutch control element.

Abstract: A method of detecting a useful signal from a measurement signal that is overlaid by at least one interference signal for use in a control or regulating device, where the interference signal occurs with at least one known interference signal frequency. The method including the steps of detecting the measurement signal, performing a Fourier transformation on the measurement signal with reference to the interference signal frequency to detect the interference signal amplitude and phase, detecting the interference signal on the basis of the interference signal amplitude and phase, and removing the interference signal from the measurement signal to detect the useful signal. The Fourier transformation is performed only with reference to the known interference signal frequency to simplify the computation making it possible to detect the useful signal in real time.

Abstract: The input rotational speed of a belt-driven conical-pulley transmission is determined by measuring a wheel rotational speed and the transmission ratio and by calculating the input rotational speed therefrom. In order to ascertain the slipping of a CVT transmission, the rate of change in the transmission ratio is drawn upon, or an acoustic parameter of the transmission is used. In the fluid control system, a valve is used whose opening cross-section is controlled according to the one differential pressure. In order to oil the conical discs, injection holes of an injection tube are used that passes through a slot provided in a slide rail resting against a strand of a flexible torque transmitting member of a conical disc flexible drive.

Abstract: A clutch plate (6), as well as a method for operating a clutch (3), between the drive motor and the transmission (1) of a motor vehicle. The clutch plate includes a cylinder with a piston (14) and an actuator (15), such that a clutch release bearing (4), arranged co-axially to the central axis of the clutch, may be operated to apply an axial pre-tensioning force on the clutch release bearing and conduct an operating medium into the clutch plate for axially displacing the piston and/or the clutch release bearing. To simplify a clutch plate of this type and enhance its utilization, the clutch plate is configured and used for generating the pre-tensioning force.

Abstract: A method for operating an automated friction clutch in which a clutch load, corresponding to an energy input, is determined and the operation of the clutch is controlled as a function of the clutch load determined. Glazing of the clutch lining that results from too low an energy input, in relation to the slipping operation time of the clutch, is compensated by a specific increase of the clutch load, while premature wear is prevented by a specific reduction of the clutch load.

Abstract: A method for determining a torque characteristic of a friction clutch located in a drive train of a motor vehicle in the force flow between a drive engine and a transmission and which is closed in its rest position. At least two marker points of a regulating-path-dependent torque characteristic are determined, one of which is determined at a slipping limit of the clutch. To enhance determination of the torque characteristic, a first marker point is determined with the clutch engaged, the transmission in neutral and the engine running, by slowly disengaging the clutch until a reduction in the speed of the transmission input shaft relative to the engine speed is detected. A corresponding pair of values of this marker point with the known braking torque of the input shaft and the set position are used for adapting an existing characteristic.

Abstract: A method for regulating or controlling the transmission ratio of an automatic power-branched transmission. Power is transmitted through a shaft driven by an engine, a variable speed drive, a gear transmission, a driven shaft, and at least two control clutches. The variable speed drive and the gear transmission are connected to each other in such a way that the regulating range of the variable speed drive is traversed in one direction within a first range of transmission ratios, and is traversed in the opposite direction within a second range of transmission ratios during traversing of the entire range of transmission ratios. The shifting strategies result in reduced wear of the endless belt device and allow for comfortable changing between the transmission ratio ranges.

Abstract: The invention concerns a device for actuating a diaphragm spring clutch (20) for vehicles by means of a pneumatic, hydraulic or electric actuator (24), comprising a controller connected upstream of the actuator (24), whose output control variable actuates the actuator (24). To compensate for the strong nonlinearity of the releasing force over the releasing stroke that is typical of diaphragm springs, a controller is used, whose characteristic curve is plotted in such a way that this nonlinear curve of the releasing force is at least approximately compensated via a correspondingly coordinated actuation of the actuator (24), so that it remains essentially identical over the releasing stroke.

Abstract: A method for controlling or regulating torque of a startup clutch of a motor vehicle. The method reliably prevents unintentional rolling of the motor vehicle down a grade and enables a comfortable maneuvering mode, which requires no separate actuation of an operating element for activating the maneuvering mode and enables a precisely dosed speed definition, while on a grade. Adjustment of the speed is substantially independent from the surface grade and the load of the motor vehicle. A startup and maneuvering control device acquires driving resistance data, determines a driving resistance value and, with that, determines a base value of the clutch torque of the automated startup clutch, with the base value being adjusted depending upon the accelerator pedal.