A method for preventing stalling of an internal combustion engine of a motor vehicle, wherein the motor vehicle has at least one internal combustion engine, at least one automatically controlled clutch, and at least one transmission, wherein a drive shaft of the internal combustion engine can be coupled to a transmission input shaft of the transmission by means of the clutch to transmit torque, wherein the clutch is disengaged if a calculated rotational speed value of the drive shaft is less than a certain threshold value, and wherein the rotational speed value is calculated, in particular continually or continuously, as a function of a determined, current rotational speed of the drive shaft and as a function of a determined, current speed gradient of the drive shaft.

A method of controlling an all-wheel-drive system connect event including providing a power transmission apparatus having a clutch, a propeller shaft, and a rear drive unit with a clutch pack assembly. The rear drive unit clutch pack is actuated by creating a model of the propeller shaft rotational speed, adapting the model parameters to compensate for temperature and vehicle wheel speed, storing the model, adapting the model utilizing information collected during a previous all-wheel-drive system connect event, and developing a set point for the clutch driving element utilizing the model and a multi-loop control architecture. The power transmission apparatus clutch is then engaged.

A clutch control device includes a clutch device that disconnects and connects a power transmission between an engine and a gearbox, a clutch actuator that drives the clutch device and changes a clutch capacity, an ECU that calculates a control target value of the clutch capacity, a clutch lever that manually operates the clutch device, and a clutch lever operation amount sensor that converts an operation amount of the clutch lever into an electrical signal, wherein the ECU calculates a clutch operation speed on the basis of the operation amount detected by the clutch lever operation amount sensor, and changes a disconnection and connection speed of the clutch device according to the clutch operation speed.

A method is disclosed for reducing chatter vibrations of a friction clutch controlled automatically by a clutch actuator on the basis of a target clutch torque (M(s)) assigned to a clutch torque which is to be transmitted. The friction clutch is positioned in a drivetrain between an internal combustion engine and a transmission, having a present actual clutch torque which is marked by vibrations as a result of vibrations (M(i)). From a transmission behavior of the present actual clutch torque (M(i)), an absolute amplitude and a phase of an input signal detected at the output of the friction clutch and conveyed to a regulator are ascertained, and a phase-selective disturbance torque is ascertained. From the phase-selective disturbance torque, a phase-correct correction torque (M(k)) is determined, and the target clutch torque (M(s)) is corrected by the regulator. The correction torque (M(k)) is weighted with a specifiable intensification factor.

The invention relates to a method for reducing occasionally occurring vibrations, in particular chatter vibrations of a unit controlled automatically by an actuator, in particular a clutch actuator, on the basis of a target torque assigned to a clutch torque that is to be transmitted, in particular a target clutch torque, in particular a unit located in a drivetrain of a motor vehicle between a combustion engine and a transmission, in particular a friction clutch having an actual present clutch torque which is marked by vibrations as a result of occasionally occurring vibrations, wherein from an input signal which is representative of the vibration-marked torque on the basis of a known transfer behavior of the actual present torque vibration components of known form with unknown prefactors are continuously ascertained, a phase-correct correction torque is determined from these, and the target torque is corrected using the latter. In order to be able to separate a plurality of vibration components from one another and resolve them, an estimation model is made the basis of the input signal, and by means of the estimation model the prefactors are determined on the basis of a recursive method of the smallest square errors.

A method for parameterizing a software damper is disclosed. A target clutch torque affected in specified operating states by chatter vibrations is corrected by a software damper, wherein a transfer behavior of a clutch torque transferred via a friction clutch based on the target clutch torque is ascertained during a modulation of the target clutch torque. The software damper is parameterized with the help of the ascertained transfer behavior. To parameterize the software damper quickly and comprehensively, the target clutch torque is modulated by a broadband excitation in a frequency range of the chatter vibrations, and the transfer behavior is ascertained depending on operating parameters of the drivetrain.

A vehicle includes a driveshaft, first axle, second axle, first clutch, second clutch, and controller. The driveshaft is selectively coupled to outputs of the first and second axles by the first and second clutches, respectively. The controller is programmed to, in response to a command to reconnect the driveshaft to the outputs of the first and second axles, close the second clutch to transfer loads from the second axle to the driveshaft, adjust the slip speed of the first clutch to within a target range, and close the first clutch.

A clutch control method for a vehicle includes steps of: calculating, by a controller, an estimated clutch torque by substituting a plurality of parameters, and a sensed stroke of a clutch actuator into a predetermined characteristic function; updating, by the controller, the parameters as new values by a prediction error method using a torque error, which is a difference between a reference clutch torque and the estimated clutch torque; calculating a desired stroke by substituting a desired clutch torque and the updated parameters into a predetermined characteristic inverse function; and driving the clutch actuator based on the calculated desired stroke to control the clutch by the controller. The plurality parameters represent physical properties of a clutch, and the predetermined characteristic function represents characteristics of a clutch transmission torque to a clutch actuator stroke. In addition, the predetermined characteristic inverse function represents a clutch actuator stroke to a clutch transmission torque.

A control device for a lock-up-clutch installed in a torque converter arranged between an engine and an automatic transmission mechanism includes an engagement control means that carries out a calculation to increase an engaging capacity of the lock-up-clutch with the passage of time during an engagement control time in which the torque converter is shifted from a converter condition to a lock-up condition in which the prime mover drives an auxiliary device and in which when, during the control to increase the engaging capacity of the lock-up-clutch, an input torque to the torque converter from the engine is increased due to reduction in load of the auxiliary device, the engagement control means promotes the increase of the engaging capacity of the lock-up-clutch based on the amount of increase of the input torque thereby eliminating undesired pressure shortage that would be induced in the period toward the lock-up condition.

A method for learning a torque-stroke (T-S) curve of an electric motor controlled dry clutch system is disclosed. The method includes calculating a position change value A for allowing a position change point P3 corresponding to an arbitrary torque y3 on a previous T-S curve C1 to follow-up and be moved to an expectation T-S curve C3, by a control unit, calculating a probability Pr_X3 to allow the position change value A to consider various environmental factors of a clutch within a valid range, and multiplying the probability Pr_X3 to the position change value A to calculate a final position change value A, by the control unit, and calculating a new point P3 by applying the final position change value A to the position change point P3 of the previous T-S curve C1, and generating a final T-S curve connecting the new point P3 and a touch point to learn, by the control unit.