In ore aspect, a method is provided or braking a work vehicle including an engine and a hydrostatic drive system including a hydraulic pump configured to be rotationally driven by the engine and a hydraulic motor fluidly coupled with the hydraulic pump through a closed hydraulic loop of the hydrostatic drive system. The hydraulic pump may be configured to fluidly drive the hydraulic motor. The method may include receiving an operator request to reduce a ground speed of the work vehicle. The method may include monitoring a fluid temperature of a hydraulic fluid associated with the closed hydraulic loop and automatically controlling at least one of a pump displacement of the hydraulic pump or a motor displacement of the hydraulic motor based on the operator request and the monitored fluid temperature to adjust hydrostatic braking of the work vehicle and thereby reduce the ground speed of the work vehicle.

A vehicle drive device includes a first drive unit that drives first wheels; a second drive unit that drives second wheels; and a control device. When the state of charge of an electrical storage device is less than a first threshold value and a vehicle speed is less than a second threshold value, the control device performs control such that when the vehicle speed is greater than or equal to zero and required drive power is greater than or equal to zero, the operating mode of the first drive unit is set to a second mode to output the required drive power from the second drive unit, and when the vehicle speed is greater than zero and the required drive power is less than zero, the operating mode of the first drive unit is set to a first mode so the first drive power source can generate electric power.

A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting the driving and driven pulleys. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes detecting a stall condition indicative of the vehicle being stalled, and, responsive to the detection, setting the piston force to be zero.

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 acceleration method for a hybrid drivetrain includes providing the hybrid drivetrain, setting an initial torque transmission ratio of a belt-drive transmission to a lower transmission ratio, and opening a first disconnect clutch to interrupt torque transmission between an internal combustion engine and an electric machine. The method also includes receiving an acceleration command, shifting the torque transmission ratio with a transmission adjustment gradient from the lower transmission ratio towards an upper transmission ratio, increasing a rotor speed of a rotor shaft of the electric machine with a rotor shaft adjustment gradient, and engaging a first disconnect clutch to rotate an ICE shaft to start the internal combustion engine and increase a rotational speed of the ICE shaft towards a current rotor speed.

While a vehicle is traveling in an automatic driving mode, an auto-driving oil pressure changing unit makes the engagement pressure of hydraulic oil supplied to a release-side engagement device to be released during a downshift of a stepwise shifting unit, higher than the engagement pressure set during traveling in a manual driving mode, so that retraction of the acceleration due to a drop of drive torque during the downshift is reduced. At this time, an auto-driving rotating machine controller makes drive-side MG2 torque generated from a second rotating machine, larger than that generated during traveling in the manual driving mode, so as to speed up the progress of the downshift, and prevent retraction of the acceleration from being prolonged.

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 vehicle drive device includes a first drive unit that drives first wheels; a second drive unit that drives second wheels; and a control device. When the state of charge of an electrical storage device is less than a first threshold value and a vehicle speed is less than a second threshold value, the control device performs control such that when the vehicle speed is greater than or equal to zero and required drive power is greater than or equal to zero, the operating mode of the first drive unit is set to a second mode to output the required drive power from the second drive unit, and when the vehicle speed is greater than zero and the required drive power is less than zero, the operating mode of the first drive unit is set to a first mode so the first drive power source can generate electric power.

An acceleration method for a hybrid drivetrain includes providing the hybrid drivetrain, setting an initial torque transmission ratio of a belt-drive transmission to a lower transmission ratio, and opening a first disconnect clutch to interrupt torque transmission between an internal combustion engine and an electric machine. The method also includes receiving an acceleration command, shifting the torque transmission ratio with a transmission adjustment gradient from the lower transmission ratio towards an upper transmission ratio, increasing a rotor speed of a rotor shaft of the electric machine with a rotor shaft adjustment gradient, and engaging a first disconnect clutch to rotate an ICE shaft to start the internal combustion engine and increase a rotational speed of the ICE shaft towards a current rotor speed.

As a driving source, an engine and an assist motor are provided. An engine control module includes a torque assist control unit for controlling the assist motor by a plurality of types of switching patterns having different torque assist levels. A CVT control unit includes a torque assist coordination control unit that, when a torque assist request is input from the torque assist control unit, carries out the control that increases commanded hydraulic pressure so as to increase the hydraulic pressure of hydraulically operated members. When carrying out the control that increases the commanded hydraulic pressure, the torque assist coordination control unit unifies the levels of the commanded hydraulic pressure regardless of the types of the switching patterns.