Volvo Truck Corporation

Volvo Lastvagnar Ab

Henrik Ryberg

Johan Bjernetun

Lars Karlsson

Erik Lauri

Svante Karlsson

Fredrik Karpenman

Johan Fries

Fredrik Sjöqvist

Behrooz Razaznejad

Sami Aho

A vehicle powertrain includes a propulsion unit having a propulsion unit auxiliary brake, a transmission, driven wheels and a control unit arranged to control at least the transmission, where the propulsion unit is drivingly connected to the driven wheels via a clutch and different engagable gear ratios in the transmission. The control unit is arranged to perform the following steps when upshifting: A corresponding method, a computer program, a computer readable medium, and a control unit for controlling the powertrain are also provided.

Vehicle powertrain and a method for gear upshifting

A method is provided for controlling an automatic transmission unit including at least a transmission with different selectable gear ratios and a clutch and being associated with a propulsion unit for a vehicle. The method includes operating the vehicle at a prevailing vehicle speed (v) in a downslope with the automatic transmission unit in a neutral gear or disengaged from the propulsion unit; operating the propulsion unit in an idle mode of operation; controlling the automatic transmission unit so as to select a gear which is a relatively low gear with regard to the prevailing vehicle speed (v), while maintaining the automatic transmission unit in a neutral gear or disengaged from the propulsion unit; and engaging the clutch to be slipping between the propulsion unit and the automatic transmission unit in order to adapt the rotational speed of the propulsion unit to the gear ratio of the relatively low gear.

Method and arrangement for controlling an automatic transmission unit

A method and device are provided for controlling disengagement of an automated vehicle master clutch arranged in a vehicle drivetrain between a vehicle propulsion unit and a step geared transmission. The method includes the steps of determining a first output torque of the propulsion unit prior to initiation of a master clutch disengagement procedure, computing a second output torque of the propulsion unit in dependence of at least the first output torque, and where the second output torque is closer to zero torque than the first output torque, initiating the master clutch disengagement procedure by initiating an oscillation in drive shafts by abruptly altering propulsion unit output torque from the first to the second output torque, and disengaging the master clutch when the oscillation has reached a first oscillation turning point. Benefits can include faster gear shifting and better comfort with maintained transmission durability.

Method and device for controlling disengagement of an automated vehicle master clutch

Method for protecting a clutch of a vehicle, said vehicle being provided with an engine, drive wheels and an automated manual transmission for transmitting drive power from said engine to said drive wheels. A controller can execute the steps of: sensing a power demand from the driver which results in a clutch control where the clutch is partly engaged and clutch slip occurs, measuring travelling distance(s) of the vehicle during a predetermined first time interval, initiating a first warning measure, in order to alert the driver of excessive clutch slip, if the vehicle has traveled less than a predetermined distance during said predetermined first time interval.

Method for clutch protection

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Göteborg, Sweden

Henrik Ryberg