Systems and methods for operating a power take off of a vehicle are described. In one example, operation of the power take off may be maintained even when slip of a power take off clutch is detected. In particular, the power take off may be operated at a lower output until the power take off may handle larger loads.

A method of controlling a component of a powertrain of a vehicle is provided. The method comprises calculating an estimated clutch surface friction coefficient as a function of an initial clutch surface friction coefficient, a temperature of the clutch, and a rotational speed difference between a driving part and a driven part of the clutch; and adjusting a command signal to the component of the powertrain based upon the estimated clutch surface friction coefficient. A method of controlling a component of a powertrain of a vehicle comprises: estimating a clutch touchpoint x.sub.ct of a clutch controlled by a clutch actuation system including a ballramp system, based on the variables of the system to determine the translation of the ball for which the clutch will transmit torque; and adjusting a command signal to the component of the powertrain based upon the estimated clutch touchpoint x.sub.ct of the clutch.

A method to estimate an amount of force in a clutch pack of a clutch actuation system. The method includes engaging an actuation motor to apply a set point force to the clutch pack and monitoring a position of the actuation motor when the set point force is applied. Additionally, the method includes determining one or more clutch clamping curves and one or more clutch releasing curves based on a relationship between the position of the actuation motor and an amount of torque applied by the actuation motor at position of the actuation motor. The method further includes modeling one or more frictional characteristics of the clutch actuation system and estimating an amount of clamping and releasing force within the clutch pack by using a control unit. The amount of torque applied to the clutch pack between the clutch clamping and releasing curves at the set point force is maintained.

The present disclosure provides a method for learning a kisspoint of an engine clutch in a hybrid vehicle, which performs kisspoint learning of an engine clutch while driving by learning hydraulic pressure at the time when motor torque varies by gradually increasing clutch hydraulic pressure in an open state of the engine clutch when a driving load of a vehicle is constant to increase a kisspoint learning frequency of the engine clutch and improve kisspoint accuracy.

A method is provided for controlling a drivetrain of a vehicle, wherein the drivetrain comprises a multi-clutch transmission. The gear shift of the multi-clutch transmission is adapted to be performed either by power cut shift or by power shift dependent on predetermined vehicle shift conditions. The method includes detecting at least one of a plurality of indications of slippery road conditions and setting a slip risk factor, wherein the slip risk factor is dependent on the indication of slippery road conditions. If the slip risk factor is above a first predetermined threshold value the method further comprises controlling the multi-clutch transmission such that an upcoming gear shift is performed as a power-shift independently of if upcoming shift was determined to be performed as a power-cut shift or as a power shift.

A method for controlling a manual transmission includes using a controller to determine a desired torque transmitted through an input clutch for the desired gear after a shift lever is moved to a desired gear position and while a clutch pedal is being released for engaging the clutch; inferring torque in the vehicle drive assembly; using inferred torque to determine clutch torque; and using the controller to automatically adjust a clutch actuator such that a difference between the desired torque and the inferred torque is reduced.

A dog clutch engagement method of an electric four-wheel drive vehicle includes steps of: when dog clutch engagement is requested during driving, determining a target synchronization speed of the input gear to be a sum of an estimated speed and an offset speed of the output gear; operating a drive unit so that an input gear follows the target synchronization speed; when an actual speed of the input gear reaches the target synchronization speed, moving a sleeve to a meeting position at which the sleeve is in contact with the input gear; and when the actual speed of the input gear is synchronized with an actual speed of the output gear, transporting the sleeve to an engagement position at which the input gear and the output gear are coupled.

Clutch temperature management in a slip control method and arrangement for a drivetrain including a continuously variable transmission is described herein. The drivetrain includes a clutch that is so controlled as to slip when a torque higher than the usable torque attempts to pass through. The temperature data from the clutch is used to determine the usable torque. Accordingly, the clutch prevents the prime mover from stalling.

A method of controlling a hybrid power train may include: driving a first input shaft connected to a second motor-generator by the second motor-generator to synchronize a speed of a driven gear of a target gear position with a speed of an output shaft; moving a sleeve to directly connect the second input shaft, the output shaft, and the driven gear of the target gear position; decreasing torque of the first motor-generator and increasing torque of the second motor-generator to converge torque transferred from the second motor-generator to the output shaft, to torque of the output shaft; moving the sleeve to release the second input shaft and maintain only the output shaft and the driven gear; and increasing torque of an engine and decreasing the torque of the second motor-generator to converge torque transferred from the engine to the output shaft, to the torque of the output shaft.

A method for operating a dual-clutch transmission of a motor vehicle, wherein a first clutch is operated closed or engaged and in this way a first transmission branch is driven, in which a current actual gear is engaged, and in a pre-selection phase for a gear changed to a desired gear in a second transmission branch, the desired gear is engaged, and in a second clutch, a clutch hydraulic system is filled and, in this way, the second clutch is closed. The gear change shall be made faster. The filling of the clutch hydraulic system is begun already during the pre-selection phase, and, in this case, the clutch hydraulic system is filled in the pre-selection phase but at most up to reaching a touch point of the second clutch.