Zf Friedrichshafen Ag

Friedrichshafen Ag

Peter Herter

Franz Bitzer

Rainer Petzold

Mario Steinborn

Joachim Staudinger

Rupert Kramer

Roland Mair

Ingo Sauter

Johannes Kemler

Thomas Jäger

Florian Schneider

Robert Anthony Sayman

Ronald Peter Muetzel

Maik Wurthner

Norbert Wiencek

Martin Miller

Marcus Gansohr

Andelko Vesenjak

Wolfgang Groener

Ramon Cordt

Jim Devore

Abu Samra Muneer

Manuel Karrer

A method for operating a drivetrain of a motor vehicle is disclosed. The operation of assemblies of the motor vehicle is controlled and/or regulated by taking into account a loss torque of the drivetrain, such that when a defined first operating condition of the motor vehicle is fulfilled, then as a function of a torque of a drive aggregate () of the drivetrain, as a function of a drag torque of a transmission () of the drivetrain, and as a function of a first sum of known loss torques of the drivetrain, a second sum of the unknown loss torques of the drivetrain is determined. Thereafter, the operation of assemblies of the motor vehicle is controlled and/or regulated taking into account the first sum of the known loss torques and taking into account the second sum of the unknown loss torques.

Method and control device for operating a motor vehicle

A method for assuring that a signal, for damping drive train vibrations, is overlaid during the same time period as the drive train vibration, and not delayed by one time period. The method comprises the steps of continuously calculating a correction torque for the vibration damping, determining, through a parallel signal path, whether the vibration damping is to be activated or deactivated, and overlaying the correction torque to the drive train vibration, if the necessity arises for activation of the vibration damping.

Method for damping vehicle drive train vibrations

A method of controlling a pneumatic actuator for actuation of a pneumatically actuated device. The actuator comprises a piston and a pneumatic cylinder, the piston is arranged to move axially within the pneumatic cylinder. The piston is moved as a function of a pressure in a pressure chamber of the pneumatic cylinder, and the pressure in the pressure chamber is adjusted by a control unit which controls at least a valve and/or a pressure regulator and/or a pressure generating device. A pilot control component, for the control, is determined as a function of at least a sliding friction force and/or at least a static friction force of the pneumatic actuator.

Method for controlling an actuator

A method of actuating an assembly of a transmission, with which are associated a plurality of actuators with whose help the assembly can in principle be actuated, such that out of the actuators available in principle for actuation, a control unit selects at least one actuator for the actual actuation and activates the selected actuator with an output signal in such manner that a status parameter of the actuated assembly corresponds to or follows a control-side nominal value, such that out of the actuators available in principle for actuating the assembly, the control unit selects at least one actuator for the actual actuation of the assembly in such manner that, for all the actuators available in principle for actuating the assembly over the operating life of the transmission, the extent of their utilization is approximately uniform.

Method for activating a unit of a transmission

A through-connection clutch, for transferring torque between a motor and transmission of a vehicle, which has a friction clutch and a form-locking clutch. The form-locking clutch is disposed radially within the friction clutch, and the clutches can be actuated independently of each other. To minimize the required installation space, the through-connection clutch can be activated flexibly, but is still inexpensive to produce and ensures low-wear yet safe and comfortable torque transfer in a drive train of a vehicle. A pressure plate of the friction clutch and a form-locking element of the form-locking clutch are concentric, rotationally fixed together, and movable toward one another, and can be actuated via an actuation unit, which is rotationally decoupled from the pressure plate and the form-locking element. Depending on the operating situation, the friction clutch and/or the form-locking clutch is selectively activated one or more times.

Through-connection clutch and method for the actuation thereof

A method of initializing the mass of a motor vehicle after a restart, for controlling a starting process of the motor vehicle a from a standstill. During operation of the motor vehicle, its mass is computed and the determined mass values are stored and, from the stored mass values, a vehicle-specific maximum mass value and/or a vehicle-specific minimum mass value is determined. The vehicle-specific maximum mass value and/or the vehicle-specific minimum mass value, determined in this manner, is subsequently used for initializing the mass of the motor vehicle after restarting the vehicle.

Method for initializing the mass of a motor vehicle

A method is proposed for controlling a through-connection clutch of a vehicle, in which an interlocking portion of the clutch is opened when the drive-train is virtually free from torque, a shifting operation is then carried out, and after the shifting operation the clutch is closed again. According to the invention, the torque transmitted by the interlocked connection in the clutch is influenced by controlling the motor in order to produce a torque-free condition at the interlocked connection in the clutch, in such manner that the interlocked connection is pre-stressed before the torque-free condition has been reached and separated immediately only when the torque-free condition is reached.

Method for controlling a rolling or coasting function of a vehicle

A method of operating a transmission positioned between a drive aggregate and an axle drive, a transmission input shaft is connected, via a clutch, with the drive aggregate, and a transmission output shaft is connected with the axle drive and power can be diverted from the transmission to drive a power take-off. The PTO is activated by an engine intervention, shifting the transmission to neutral and disengaging the clutch. Thereafter, the clutch is partially engaged at either a position dependent or distance dependent clutch speed while monitoring the input rotational speed and drive aggregate rotational speed. When the input rotational speed approximately equals the drive aggregate rotational speed and the idle rotation speed of the drive aggregate, the clutch is no longer being engaged at the position dependent or distance dependent clutch speed, but is fully engaged at a maximum clutch speed.

Method for operation of a transmission

A method of determining and reducing vibrations caused by a clutch () in a drivetrain () 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 () is used to detect the occurrence of vibrations in the drivetrain () and the torque sensor () is used to determine vibration amplitude.

Method and device for determining and dampening juddering vibrations of a drivetrain

A method and a device for controlling a clutch, for example an automatic friction clutch forming part of a drive train of a motor vehicle, for a torque transfer between an engine and a transmission, with the clutch having significant clutch way points assigned to it. For achieving the operational readiness of the clutch over the shortest possible time period, whereby an accurate clutch adjustment is still guaranteed, a clutch way point coordinate system is monitored by checking the point of engagement of the clutch, established through a learning process and having at least a relevant clutch way point for the starting procedure. In case of any recognized change(s), the clutch way point is suitably corrected or otherwise used as is.

Method and device for controlling a clutch by clutch way point coordinate system

A method for actuating a clutch () 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 () is determined as a function of a rotational speed difference between an input speed of a transmission () of the drivetrain and an idling speed of a power engine () 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.

Method for actuating a clutch of a drivetrain

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.

Clutch system

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.

Procedure for controlling a hydraulic or pneumatic transmission control unit

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.

Method for controlling an automated friction clutch

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.

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Ravensburg, Germany

Peter Herter