A method for operating a power shiftable transmission of a motor vehicle, the transmission including a control unit, an input shaft, an output shaft, a gear set, and multiple shift elements, the method including transmitting, with the control unit, a request for a reduction of a drive torque acting on the input shaft for carrying out an upshift, and determining, with the control unit, whether the reduction is completely possible, partially possible, or impossible based on a signal. When the reduction is completely possible, the method includes controlling, with the control unit, a torque transmission rate of a shift element of the multiple shift elements to be engaged during the upshift according to a first way. When the reduction is partially possible or impossible, the method includes controlling, with the control unit, the torque transmission rate according to a second way, the second way differing from the first way.

A method for operating a power shiftable transmission of a motor vehicle, the transmission including a control unit, an input shaft, an output shaft, a gear set, and multiple shift elements, the method including transmitting, with the control unit, a request for a reduction of a drive torque acting on the input shaft for carrying out an upshift, and determining, with the control unit, whether the reduction is completely possible, partially possible, or impossible based on a signal. When the reduction is completely possible, the method includes controlling, with the control unit, a torque transmission rate of a shift element of the multiple shift elements to be engaged during the upshift according to a first way. When the reduction is partially possible or impossible, the method includes controlling, with the control unit, the torque transmission rate according to a second way, the second way differing from the first way.

An apparatus and system for actuating a manual gearbox, particularly of a motorcycle having a drive engine, and for carrying out a gear change while the clutch is engaged between the drive engine and the manual gearbox. The apparatus has a selector shaft, which can be actuated rotationally, and a gear-selector drum, which can be actuated rotationally. The gear-changing apparatus has a gear-change lever provided for actuating the selector shaft, and is adapted for influencing the output torque of the drive engine. One or more magnetic sensor(s), such as Hall effect sensors, are provided for sensing rotational actuation of the selector shaft and, optionally, for sensing rotational actuation of the gear selector drum. The sensor(s) send a signal to a controller and mechanisms known for affecting a change in gear to a lower or higher gear.

A method of controlling engine torque according to transmission hydraulic pressure is performed by an engine torque control system of a vehicle. The method includes connecting an engine torque converter to an engine and an automatic transmission of the vehicle, calculating a required turbine torque after confirming an engine torque control condition, deriving and storing a value of turbine torque factor learning through turbine torque factor learning according to shift type and shift time, converting the stored value of turbine torque factor learning into an engine torque control value, and requesting the engine torque control value to be applied to engine output, by an engine torque controller during shifting of the automatic transmission, so that a new turbine torque calculation is performed through a hydraulic pressure reference at the beginning of physical shifting, thereby preventing a shift shock and transmission damage caused by unreasonably excessive or insufficient engine torque.

A gearbox (100) includes an input shaft (105), which is connected to a drive source, and a first and a second proportionally controllable shift element (A-F). A method (200) for open-loop control of the gearbox (100) includes: determining (210) an absolute torque demand (330) on the drive source on the basis of a profile controlled by way of an open-loop system (340) and a profile controlled by way of a closed-loop system (345); determining (220) whether the absolute torque demand (330) threatens to exceed a predetermined threshold value (335); and, in response, reducing (225) the portion controlled by way of the closed-loop system (345).

An apparatus and system for actuating a manual gearbox, particularly of a motorcycle having a drive engine, and for carrying out a gear change while the clutch is engaged between the drive engine and the manual gearbox. The apparatus has a selector shaft, which can be actuated rotationally, and a gear-selector drum, which can be actuated rotationally. The gear-changing apparatus has a gear-change lever provided for actuating the selector shaft, and is adapted for influencing the output torque of the drive engine. One or more magnetic sensor(s), such as Hall effect sensors, are provided for sensing rotational actuation of the selector shaft and, optionally, for sensing rotational actuation of the gear selector drum. The sensor(s) send a signal to a controller and mechanisms known for affecting a change in gear to a lower or higher gear.

A gearbox (100) includes an input shaft (105), which is connected to a drive source, and a first and a second proportionally controllable shift element (A-F). A method (200) for open-loop control of the gearbox (100) includes: determining (210) an absolute torque demand (330) on the drive source on the basis of a profile controlled by way of an open-loop system (340) and a profile controlled by way of a closed-loop system (345); determining (220) whether the absolute torque demand (330) threatens to exceed a predetermined threshold value (335); and, in response, reducing (225) the portion controlled by way of the closed-loop system (345).

A method of controlling engine torque according to transmission hydraulic pressure is performed by an engine torque control system of a vehicle. The method includes connecting an engine torque converter to an engine and an automatic transmission of the vehicle, calculating a required turbine torque after confirming an engine torque control condition, deriving and storing a value of turbine torque factor learning through turbine torque factor learning according to shift type and shift time, converting the stored value of turbine torque factor learning into an engine torque control value, and requesting the engine torque control value to be applied to engine output, by an engine torque controller during shifting of the automatic transmission, so that a new turbine torque calculation is performed through a hydraulic pressure reference at the beginning of physical shifting, thereby preventing a shift shock and transmission damage caused by unreasonably excessive or insufficient engine torque.

When an inertia phase has started while torque phase control is being executed, the torque phase control is ended, a target torque capacity of an engaging element in inertia phase control is corrected on the basis of a difference between the target torque capacity of the engaging element at the time when the inertia phase has started and the target torque capacity of the engaging element at the time when the torque phase control has completed (or a difference between the target torque capacity of the engaging element at the time when the inertia phase has started and the target torque capacity of the engaging element, which is set at the time when the inertia phase control has started), and the inertia phase control is started.

Provided are gearboxes including compound planet gear assemblies as well as methods of using such gearboxes. A gearbox includes at least a first ring gear and a second ring gear. Depending on the current gear selection, one of these ring gears may be engaged with a shifting mechanism or not engaged with any ring gears when in a neutral gear. The first ring gear may be constantly engaged with a first planet gear of a compound planet gear assembly, while the second ring gear may be constantly engaged with a second planet gear of the same compound planet gear assembly. The first planet gear may be also engaged with a sun gear coupled to a shaft. Another shaft is coupled to the shifting mechanism. Different gear selections of the gearbox engage different ring gears to the shifting mechanism thereby changing the rotational speed ratio of the two shafts.