A method for performing rotational speed synchronisation of a first transmission component having a first initial rotational speed with a second transmission component having a second initial rotational speed, so that they rotate with the same final rotational speed during a gear switch from an initial driving gear to a final driving gear in a stepped gear transmission for a hybrid electric or electric drive train having an electric traction motor. The method including calculating a total frictional work resulting from performing the total rotational speed synchronisation by means of a mechanical synchroniser of the stepped gear transmission only, and if the calculated total frictional work exceeds a maximal frictional work of the mechanical synchroniser, performing the rotational speed synchronisation by means of both the electric traction motor and the mechanical synchroniser.

A transmission speed change control system using effective torque force as a master control parameter instead of throttle percentage signal and engine speed signal. Response time of this system is extremely shorter than existing system, therefore, when this transmission speed change control system is used in cooperation with a continuously variable transmission, the real-time speed ratio matching, can be realized, and the transmission system is maintained in an optimal working condition at any time, so as to improve the transmission efficiency of the transmission system. Meanwhile, the load of the power source can be adjusted without abrupt change. Hence, the work efficiency of the power source is improved, and the service life thereof is prolonged. At the same time, compared with the existing transmission system, the composition and control logic of this control system are simpler and more efficient, and easier to calibrate and adjust.

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 vehicle includes a drive wheel, an engine, an accelerator pedal, a torque converter, a clutch, and a controller. The drive wheel is configured to propel the vehicle. The engine is configured to generate power and to deliver power to the drive wheel to accelerate the vehicle. The accelerator pedal is configured to generate an acceleration request based on a pedal position. The torque converter is disposed between the engine and the drive wheel. The clutch is disposed between the engine and the drive wheel and is configured to bypass the torque converter. The controller is programmed to, in response to depressing the accelerator pedal to a position that corresponds with accelerating the vehicle at a desired magnitude, adjust the torque of the engine to accelerate the vehicle at the desired magnitude, regardless of the state of the clutch.

A control method is provided for controlling an internal combustion engine for a vehicle configured to engage a lockup clutch during a fuel cut, and to decrease a lockup hydraulic pressure at a fuel cut recovery to bring the lockup clutch to a slip engagement. The control method includes estimating a torque of the internal combustion engine generated by the fuel cut recovery when a fuel cut recovery condition is satisfied. The control method further includes decreasing a decrease amount of the lockup hydraulic pressure as the torque is greater.

A shifting system for a human-powered vehicle comprises a controller. The controller is configured to receive a driving torque and a cadence of the human-powered vehicle from at least one sensor. The controller is configured to determine a permitted shift timing based on the driving torque and the cadence. The controller is further configured to control a shift mechanism to perform a gear shift during the permitted shift timing in accordance with a permitted cadence range and a first threshold of the driving torque.

A system and method for controlling backlash in a vehicle powertrain includes the step of controlling a torque request of the powertrain with a first control strategy after an occurrence of a backlash predictor and before an occurrence of a backlash. Another step may be employed whereby the torque request is controlled with a second control strategy after the first control strategy and before the occurrence of the backlash such that a torque request level is below a highest torque request level obtained during the first control-strategy.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. An integrated actuator housing includes a single external power access for the shift actuator. A controller interprets a shaft displacement angle, determines if the transmission is in an imminent zero or zero torque region, and performs a transmission operation in response to the transmission in the imminent zero or zero torque region.

An abnormality determination device for a continuously variable transmission is provided in which since the abnormality determination device which calculates a compression stiffness of a metal belt from an amplitude ratio between a variable component of the rotational speed of an input shaft and a variable component of the rotational speed of an output shaft, a phase lag that is an indicator of the difference in phase between a variable component of the rotational speed of the input shaft and a variable component of the rotational speed of the output shaft, and a belt pitch radius of a drive pulley or a driven pulley, and determines whether a metal ring has broken by comparing the compression stiffness of the metal belt with a preset reference compression stiffness.

A shift change practice device capable of improving the effect of learning a shift change operation is provided. The shift change practice device includes: an optimum speed calculation unit that calculates an optimum value or an optimum range of an engine revolution speed in the event of a shift change; a revolution speed comparison unit that determines whether or not a detected revolution speed that is a detected value of the engine revolution speed is equal to the optimum value or whether or not the detected revolution speed is included in the optimum range, in a state where a clutch is disconnected; and a notification instruction unit that instructs a notification device to give a predetermined notification to a driver when the detected revolution speed is equal to the optimum value or the detected revolution speed is included in the optimum range, in the state where the clutch is disconnected.