A hybrid system includes a transmission control module, a power source, a transmission, and a drive train. The transmission control module partially operates the hybrid system and receives operating information from various components of the system, calculates power losses in the drive train, and calculates the driving torque needed to reach a target power profile determined from a driver's input.

A controller of a power transmission system for a vehicle includes an electronic control unit. When a difference between a secondary pressure set by use of a command pressure of the electromagnetic control valve for the secondary pulley, and an actual pressure obtained by a hydraulic pressure sensor, is larger than a predetermined pressure difference, the electronic control sets a primary pressure and the secondary pressure such that a speed ratio of a continuously variable transmission becomes substantially equal to a maximum value. The electronic control unit determines that there is an abnormality that an output pressure of the electromagnetic control valve for a secondary pulley is low, when the speed ratio is smaller than a predetermined first determination value, and determines that there is an abnormality in the hydraulic pressure sensor, when the speed ratio is larger than a predetermined second determination value.

A control arrangement for use in a drive arrangement of a vehicle includes an engine, a hydrostatic transmission, a load sensing means configured to detect a load on the engine, and an engine speed controller for controlling the engine. The arrangement further includes a pressure control means configured to act on a pressure in the hydrostatic transmission and a drive controller. The load sensing means generates a first signal, and based on the first signal, the drive controller generates a second signal for the engine speed controller and the pressure control means.

A method of selecting an economy operating mode of a work machine includes detecting a current throttle position of a throttle control and a current track speed with a speed sensor, and determining a current drivetrain load of the machine as a function of motor torque, a drivetrain ratio, a drivetrain mechanical efficiency, a final drive windage factor, and a rolling radius. The method includes decreasing the current throttle command if a ratio of the current drivetrain load to an available drivetrain load is less than a load threshold. A transmission ratio of the transmission is increased by the controller to an increased transmission ratio if the ratio of the current drivetrain load to the available drivetrain load is less than the load threshold.

A method of selecting an economy operating mode of a work machine includes detecting a current throttle position of a throttle control and a current track speed with a speed sensor, and determining a current drivetrain load of the machine as a function of motor torque, a drivetrain ratio, a drivetrain mechanical efficiency, a final drive windage factor, and a rolling radius. The method includes decreasing the current throttle command if a ratio of the current drivetrain load to an available drivetrain load is less than a load threshold. A transmission ratio of the transmission is increased by the controller to an increased transmission ratio if the ratio of the current drivetrain load to the available drivetrain load is less than the load threshold.

A controller of a power transmission system for a vehicle includes an electronic control unit. When a difference between a secondary pressure set by use of a command pressure of the electromagnetic control valve for the secondary pulley, and an actual pressure obtained by a hydraulic pressure sensor, is larger than a predetermined pressure difference, the electronic control sets a primary pressure and the secondary pressure such that a speed ratio of a continuously variable transmission becomes substantially equal to a maximum value. The electronic control unit determines that there is an abnormality that an output pressure of the electromagnetic control valve for a secondary pulley is low, when the speed ratio is smaller than a predetermined first determination value, and determines that there is an abnormality in the hydraulic pressure sensor, when the speed ratio is larger than a predetermined second determination value.

An apparatus including a transmission mechanism in a power transfer path between a drive source and wheels; an oil pressure control device supplying lubricating oil to the transmission mechanism; and a control part outputting an electrical instruction to increase a flow rate of the supplied lubricating. When the control part outputs an electrical instruction to the oil pressure control device to increase a flow rate of lubricating oil supplied to the transmission mechanism, and determines that the flow rate of lubricating oil supplied to the transmission mechanism from the oil pressure control device does not increase as indicated by the electrical instruction (time t1), the control part considers that the oil pressure control device is in an abnormal state, and can impose a limitation that an absolute value of torque of the transmission mechanism transferred between the wheels and the drive source be reduced (time t1-t5).

A powertrain includes an internal combustion engine, an electric machine including a rotor, a geartrain including a pump drive mechanism, a first clutch and a second clutch and a variator for a continuously variable transmission (CVT). The internal combustion engine is rotatably coupled to the rotor of the electric machine by activation of a second clutch. The internal combustion engine is rotatably coupled to the variator by activation of first and second clutches. The rotor of the electric machine is rotatably coupled to the variator by activation of the first clutch, and the electric machine is operative in either a forward direction or a reverse direction. The geartrain is disposed to operate the pump drive mechanism to drive a fluidic pump in a first direction when the electric machine is operating in the forward direction and when the electric machine is operating in the reverse direction.

A hybrid system includes a transmission control module, a power source, a transmission, and a drive train. The transmission control module partially operates the hybrid system and receives operating information from various components of the system, calculates power losses in the drive train, and calculates the driving torque needed to reach a target power profile determined from a driver's input.

A hybrid system includes a transmission control module, a power source, a transmission, and a drive train. The transmission control module partially operates the hybrid system and receives operating information from various components of the system, calculates power losses in the drive train, and calculates the driving torque needed to reach a target power profile determined from a driver's input.