Volvo Truck Corporation

Volvo Lastvagnar Ab

Triline Ab

Lars Karlsson

Johan Bjernetun

Anders Eriksson

Marcus Steen

Sixten Berglund

Svante Karlsson

Erik Lauri

Henrik Andersson

Maria Strid

Tobias Carlsson

Jaan K&auml;rem

H&aring;kan Arv&eacute;rus

Peter Templin

Klas Bergström

Henrik Ryberg

Lennart Brusved

Erika Jakobsson

Jan Erik Lauri

Karl Marcus Ste&eacute;n

A device and a method for controlling vehicle speed in a vehicle equipped with cruise control while traveling downhill. The method involves driving a vehicle downhill with the cruise control set to a brake speed; detecting a current vehicle speed; applying the auxiliary brake to maintain the brake speed; detecting a request for a downshift from a current gear to a lower gear; and determining if a downshift is permissible at the current speed. If a downshift is not permissible, then a control unit automatically applies the service brakes to retard the vehicle speed; retarding the vehicle from a current speed to a lower speed at which a downshift to a lower gear is permissible; and performing a downshift to a lower gear when the second vehicle speed is reached. The cruise control is set to a second brake speed lower than the first brake speed.

Method and a system for controlling vehicle speed

A method for automatic calibration of a position detection sensor of an automatic transmission including a gearshift actuator, the method including registering, using the position detection sensor, the position of the gearshift actuator upon power-up of the transmission; and performing a calibration of the position detection sensor if the registered position of the gearshift actuator is outside a predetermined expected position range of the gearshift actuator or within a predetermined abnormal position range of the gearshift actuator.

Method for automatic calibration of automatic transmission

A method to control a powertrain in a vehicle during an acceleration is provided, the powertrain including a propulsion unit, a multi-clutch transmission drivingly connected to the propulsion unit, and a control unit for controlling at least the powertrain components, which control unit is provided with a prediction model including at least one simulated shift sequence for the multi-clutch transmission. The method involves monitoring at least one operating parameter of the powertrain; estimating the time (tE) between initiation of a first power upshift and initiation of a sequential second power upshift using the prediction model; and, if the estimated time is shorter than a predetermined time limit (tLIM), controlling the propulsion unit to limit the vehicle acceleration so that the time between the first and second power upshifts is increased to be at least equal to the predetermined time limit (tLIM).

Method to control a powertrain in a vehicle

A device and a method for controlling vehicle speed in a vehicle equipped with brake cruise control when the vehicle is travelling downhill are provided. The method involves driving a vehicle downhill with the brake set speed set to a first brake set speed; detecting a current vehicle speed; automatically applying a brake torque using at least an auxiliary brake to maintain the first brake set speed; and detecting a manual application of a vehicle service brake, in order to decrease vehicle speed. If a control unit detects that the driver is applying the service brake, then the control unit is automatically arranged to set the brake set speed to a second brake set speed that is lower than the first brake set speed; and to apply a brake torque using at least the auxiliary brake if a detected current vehicle speed exceeds the second brake set speed.

A cruise control arrangement is provided with a cruise control speed function and where the cruise control arrangement is provided with a set cruise speed value and a set brake cruise speed value, and where the cruise control brake function is active when the vehicle travels downhill, where the cruise control arrangement is adapted to activate at least one auxiliary brake when the vehicle speed reaches the set brake cruise speed, to apply a service brake of the vehicle in order to reduce the speed of the vehicle to a predefined first speed if the vehicle speed exceeds the set brake cruise speed when the least one auxiliary brake is delivering full brake power, where the predefined first speed is lower than the set brake cruise speed. Undesired acceleration during downhill travel can be avoided when the brake power of the auxiliary brake is not sufficient. Further, a required downshift can be delayed, which will improve the fuel consumption of the vehicle.

Arrangement and method for a cruise control brake in a vehicle

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.

Method for controlling a drivetrain of a vehicle comprising a multi-clutch transmission

A method is provided to control an engine braking operation of a vehicle provided with a dual clutch transmission. The dual clutch transmission is adapted to be set into different gear-combinations, each including an active gear selection through which torque can be transmitted, and a passive gear selection through which no torque can be transmitted. In a pre-set number of gear-combinations, the first input shaft and the main shaft have a synchronised rotation. When an engine braking operation is performed when the transmission is set in one of the pre-set number of gear-combinations modifying said engine braking operation such that a damaging load upon said spigot bearing is reduced.

Method to control an engine braking operation

A method for automatic detection of need for clutch calibration includes registering and storing in a data memory, before or in connection with engine shut down, a value of a clutch operating parameter, registering a corresponding value of the clutch operating parameter in connection with subsequent engine start up, and determining need for clutch calibration if the difference between the stored value of the clutch operating parameter and the corresponding value of the clutch operating parameter exceeds a predetermined threshold value.

Automatic clutch calibration

Method and a device for automatic selection of a better starting gear in a vehicle, including the steps of engaging a first starting gear, on driver demand controlling propulsion torque as to attempt to achieve a first take off, if the first starting gear is too high interrupting the first take off and automatically braking the vehicle, engaging a second adapted starting gear which is a lower gear compared to the first starting gear, controlling propulsion torque as to attempt to achieve a second vehicle take off, and if the second vehicle take off attempt results in a transmitting of torque to driven wheels of the vehicle being enough as to perform a take off then stop braking the vehicle. An incorrectly selected starting gear can thus be automatically changed. The starting gear change can be performed in an uphill situation.

Method and device for automatic or semiautomatic selection of a better starting gear in a vehicle

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

Automatic mechanical transmission system for a vehicle with antilock braking which is configured to selectively decouple the drive train of the vehicle from the wheels of the vehicle. The system includes a first sensor for sensing at least one operational state of the vehicle, a second sensor for sensing a wheel-lock up condition of the vehicle, and a logic control unit. The logic control unit is configured to receive signals from the first and second sensors. When the first sensor communicates a first predetermined operational state of the vehicle and the second sensor communicates a wheel-lockup condition, the logic unit directs disengagement of the drive train from the wheels. Alternatively, when a second predetermined operational state of the vehicle and wheel lock-up condition is communicated, the logic control unit directs engagement of the drive train and the wheels.

Selective anti-lock braking system

An automatic disengaging method for a master clutch dependent power take-off (PTO) arranged in a vehicle for preventing undesired movement or actions of the implements associated with the PTO and undesired wear of a clutch collar (release bearing). The PTO is driven by an engine via a master clutch between a crankshaft of the engine and an input shaft in a gearbox. The gear box further comprises an output shaft which is powered by the input shaft, optionally via an intermediate shaft. A power take-off is connected to the input shaft or, optionally, to the intermediate shaft. The system further includes a control unit connected to the master clutch and the gear box. When the control unit registers that the master clutch is disengaged, a gear is engaged in the gearbox and certain conditions are fulfilled (e.g. a parking brake has been actuated for a certain time), the control unit performs the operations of putting the gearbox in a neutral position, disable the power take-off, if the power take-off is enabled, and engage the master clutch.

Automatic disengaging/engaging method of a clutch dependent power take-off

Method for adapting an automated transmission of a heavy vehicle in consideration of a speed sensitive PTO. The method selects appropriate gears based on the constraint that the engaged PTO should remain below a set speed limit. The information about the speed limit of the PTO is used by the transmission control unit to ensure that the engine does not drive the PTO at a speed higher than the given speed limit. The engine speed may also be limited to reduce the engine speed to prevent it from exceeding the allowable PTO speed.

Method for adapting an automated transmission of a heavy vehicle in consideration of a speed sensitive PTO

A stage-geared gearbox for motor vehicles, includes an unsynchronized basic gearbox, at least one synchronized auxiliary gear and at least one control unit for controlling engagement and disengagement of the gears of the gearbox and also neutral position. In the gearbox, the control unit is arranged so as, when input signals indicating that neutral position is selected are received, to put the synchronized auxiliary gear in neutral position.

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Göteborg, Sweden

Lars Karlsson