A method to automatically control a drivetrain provided with a servo-assisted transmission; the method presents the steps of: measuring a rotation speed of the internal combustion engine; carrying out a downshift to a lower gear in an autonomous manner, when the rotation speed of the internal combustion engine reaches a lower threshold; carrying out an upshift to a higher gear in an autonomous manner, when the rotation speed of the internal combustion engine reaches an upper threshold; detecting a release of an accelerator pedal in a first instant; waiting, starting from the first instant, a time interval until a second instant, which is subsequent to the first instant; and increasing a value of the lower threshold starting from the second instant until a following pressing of the accelerator pedal, if in the second instant the rotation speed of the internal combustion engine still exceeds the lower threshold.

An extension/contraction mechanism in which an extension/contraction part is able to turn is provided. An extension/contraction mechanism according to one aspect of the present disclosure includes a first drive source connected to a sending/pulling part so as to be able to transmit a drive force, and a second drive source connected to the sending/pulling part and a turning part that rotatably supports the sending/pulling part so as to be able to transmit a drive force via a gear group. When a rotational speed transmitted to the sending/pulling part to rotate the sending/pulling part by the first drive source is equal to a rotational speed transmitted to the sending/pulling part to rotate the sending/pulling part by the second drive source, an extension/contraction part turns via the turning part. When the above rotational speeds are different from each other, the extension/contraction part is extended or contracted.

Methods and systems for a hydromechanical transmission in a vehicle are provided herein. In one example, the transmission system includes a hydrostatic assembly with a hydraulic pump in fluidic communication with a hydraulic motor. The transmission system further includes a controller configured to selectively transition between a torque control mode and a speed control mode of the hydrostatic assembly while the vehicle is on a slope.

The control method for the continuously variable transmission in the present invention detects a magnitude of an acceleration request, and when the acceleration request exceeds a preset threshold value, the control method controls a transmission ratio by switching from a first shift mode, in which a target transmission ratio is changed steplessly, to a second shift mode, which includes a stepwise change in the target transmission ratio. Then, when executing the second shift mode, a target engine rotation speed is set according to the magnitude of the acceleration request, and a step-down shift, in which the target transmission ratio is lowered stepwise according to the target engine rotation speed, is executed at an acceleration start time, and the target engine rotation speed after executing the step-down shift is retained for a predetermined period.

The control method for the continuously variable transmission in the present invention detects a magnitude of an acceleration request, and when the acceleration request exceeds a preset threshold value, the control method controls a transmission ratio by switching from a first shift mode, in which a target transmission ratio is changed steplessly, to a second shift mode, which includes a stepwise change in the target transmission ratio. Then, when executing the second shift mode, a target engine rotation speed is set according to the magnitude of the acceleration request, and a step-down shift, in which the target transmission ratio is lowered stepwise according to the target engine rotation speed, is executed at an acceleration start time, and the target engine rotation speed after executing the step-down shift is retained for a predetermined period.

A method of operating a vehicle is provided. The vehicle includes: an engine; a throttle operator moveable by a driver; a throttle valve regulating airflow to the engine; a continuously variable transmission (CVT) operatively connected to the engine; at least one ground engaging member including at least one of: a wheel and a track; a piston operatively connected to a driving pulley of the CVT for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley; and a control unit for controlling actuation of the piston and the piston force. The method includes: determining a driven pulley speed of a driven pulley of the CVT; detecting an uphill stand condition indicative of the vehicle being stopped on an uphill; responsive to the detection of the uphill stand condition, controlling the piston force based on the driven pulley speed.

A method of operating a vehicle is provided. The vehicle includes: an engine; a throttle operator moveable by a driver; a throttle valve regulating airflow to the engine; a continuously variable transmission (CVT) operatively connected to the engine; at least one ground engaging member including at least one of: a wheel and a track; a piston operatively connected to a driving pulley of the CVT for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley; and a control unit for controlling actuation of the piston and the piston force. The method includes: determining a driven pulley speed of a driven pulley of the CVT; detecting an uphill stand condition indicative of the vehicle being stopped on an uphill; responsive to the detection of the uphill stand condition, controlling the piston force based on the driven pulley speed.

An apparatus and a method for controlling a transmission of a vehicle include an agent that determines a gear stage of the vehicle based on driving information of the vehicle, shape information of a road, and/or operation information of a driver, and include a controller that performs a reward with respect to the determination of the agent and controls the transmission of the vehicle based on the gear stage determined by the agent.

An apparatus and a method for controlling a transmission of a vehicle include an agent that determines a gear stage of the vehicle based on driving information of the vehicle, shape information of a road, and/or operation information of a driver, and include a controller that performs a reward with respect to the determination of the agent and controls the transmission of the vehicle based on the gear stage determined by the agent.

A method for determining a drag torque coefficient of a transmission includes performing rotational speed synchronisation involving application of synchronisation torque to a first transmission component, and obtaining an initial rotational speed of the first transmission component before the rotational speed synchronisation, and a final rotational speed of the first transmission component after the rotational speed synchronisation, and time period for performing the rotational speed synchronisation. Also, obtaining information relating to a level of the synchronisation torque applied to the first transmission component during the rotational speed synchronisation, and information relating to a total moment of inertia associated with the first transmission component. In addition, determining the drag torque coefficient based on the obtained initial rotational speed, the obtained final rotational speed, the obtained time period, the level of the applied synchronisation torque and the total moment of inertia associated with the first transmission component.