A method and device for operating a powertrain of a motor vehicle are provided, wherein the powertrain includes an internal combustion engine, a transmission and a friction clutch arranged there between in order to control a power flow between the internal combustion engine and the transmission. The method includes the steps of detecting clutch judder, analysing clutch judder, and determining a type of clutch judder. Based on determined type of clutch judder the method further includes selecting a udder countermeasure from a number of predetermined judder countermeasures and executing selected judder countermeasure. Detected clutch judder can be taken care of in an efficient way and future clutch judder may be prevented.

A driving force distribution control device mounted on a four-wheel drive vehicle is provided. A coupling mechanism controller connects a drive shaft with an auxiliary driving wheel and sets a fastening force as a first fastening force, when an increase rate in an accelerator opening becomes more than a given value and a vehicle speed is below a given first speed, and changes the fastening force from the first fastening force to a second fastening force, when a slip of at least one of main driving wheels is detected after the fastening force is set to the first fastening force, and before a given time period has lapsed from the setting of the fastening force, or before the vehicle speed becomes faster than a given second speed. The second fastening force at least immediately after the change of the fastening force is a value larger than the first fastening force.

A driving force distribution control device mounted on a four-wheel drive vehicle is provided. A coupling mechanism controller connects a drive shaft with an auxiliary driving wheel and sets a fastening force as a first fastening force, when an increase rate in an accelerator opening becomes more than a given value and a vehicle speed is below a given first speed, and changes the fastening force from the first fastening force to a second fastening force, when a slip of at least one of main driving wheels is detected after the fastening force is set to the first fastening force, and before a given time period has lapsed from the setting of the fastening force, or before the vehicle speed becomes faster than a given second speed. The second fastening force at least immediately after the change of the fastening force is a value larger than the first fastening force.

A vehicle control device turns off a clutch to put a vehicle into an inertia operation state in response to a predetermined executing condition being met, and turns on the clutch to terminate the inertia operation state in response to a predetermined terminating condition being met during the inertia operation. The vehicle control device includes a deceleration degree calculating device, a determination device, and an operation control device. The deceleration degree calculating device calculates an actual deceleration degree. The determination device determines whether the actual deceleration degree is greater than a threshold value defined on the basis of a deceleration degree of the vehicle in an accelerator-off and clutch-on state. The operation control device terminates or maintains the inertia operation depending on a condition of the actual deceleration degree.

A method and device for operating a powertrain of a motor vehicle are provided, wherein the powertrain includes an internal combustion engine, a transmission and a friction clutch arranged there between in order to control a power flow between the internal combustion engine and the transmission. The method includes the steps of detecting clutch judder, analyzing clutch judder, and determining a type of clutch judder. Based on determined type of clutch judder the method further includes selecting a udder countermeasure from a number of predetermined judder countermeasures and executing selected judder countermeasure. Detected clutch judder can be taken care of in an efficient way and future clutch judder may be prevented.

Provided is an engagement position storage device capable of detecting a clutch engagement position of a vehicle finely and a brake system including such a device. In an engagement position storage device 2b that stores an engagement position of a clutch to engage and disengage power of a vehicle, when the vehicle becomes a traveling state in predetermined duration after acceleration in a front-back direction of the vehicle changes, the engagement position storage device 2b stores a clutch engagement position based on a clutch position detected when the acceleration changes. A brake system 1 includes a wheel latching mechanism 5 that latches wheels of a vehicle by driving a propelling member 5a by driving devices 3 and 4; and a controller 2 that controls driving of the propelling member 5a of the wheel latching mechanism 5 based on a clutch engagement position stored in the engagement position storage device 2b.

A vehicle control device turns off a clutch to put a vehicle into an inertia operation state in response to a predetermined executing condition being met, and turns on the clutch to terminate the inertia operation state in response to a predetermined terminating condition being met during the inertia operation. The vehicle control device includes a deceleration degree calculating device, a determination device, and an operation control device. The deceleration degree calculating device calculates an actual deceleration degree. The determination device determines whether the actual deceleration degree is greater than a threshold value defined on the basis of a deceleration degree of the vehicle in an accelerator-off and clutch-on state. The operation control device terminates or maintains the inertia operation depending on a condition of the actual deceleration degree.