A control device for a continuously variable transmission, which sets a target input rotational speed, or a target value of an input rotational speed of the continuously variable transmission mounted on a vehicle, such that a speed ratio is changed in a stepped manner and which controls the continuously variable transmission such that the input rotational speed becomes equal to the target input rotational speed.

This invention pertains to the field of power transmission. Machines using a power transmission mechanism for transmission of the mechanical power produced by a source (engine (2), electric motor, pneumatic and hydraulic pump) to another component of the machine (wheel (21), electric motor, electric generator, pneumatic and hydraulic pump) through multiple transmission paths (different gear ratios (14), (15)) are subjects of this invention. It is disclosed that control of a switching from one power transmission path to another is done in a manner involving simultaneous load transfer and speed synchronization rather than sequential performance of these two functions, and the resulting method developed in the invention leads to switching operations that produce less disturbance at the input of the said component. The said method is applied to the problem of controlling gearshifts in automatic transmissions of ground vehicles.

A control device for a continuously variable transmission, which sets a target input rotational speed, or a target value of an input rotational speed of the continuously variable transmission mounted on a vehicle, such that a speed ratio is changed in a stepped manner and which controls the continuously variable transmission such that the input rotational speed becomes equal to the target input rotational speed.

A control device for a continuously variable transmission, which sets a target input rotational speed, or a target value of an input rotational speed of the continuously variable transmission mounted on a vehicle, such that a speed ratio is changed in a stepped manner and which controls the continuously variable transmission such that the input rotational speed becomes equal to the target input rotational speed.

A control device for a continuously variable transmission, which sets a target input rotational speed, or a target value of an input rotational speed of the continuously variable transmission mounted on a vehicle, such that a speed ratio is changed in a stepped manner and which controls the continuously variable transmission such that the input rotational speed becomes equal to the target input rotational speed.

An apparatus for a learn control of an automatic transmission includes a storage unit configured to store an initial fill time value and a gain value corresponding to a revolution per minute (RPM) peak to peak of a turbine. An oil pressure applier is configured to apply an oil pressure to a non-operating friction element. An RPM measurer is configured to measure the RPM of the turbine, and a learn controller is configured to control the oil pressure applier to apply the oil pressure to the non-operating friction element during a preset reference time and control the initial fill time based on the RPM peak to peak of the turbine showing a difference between a measured value RPM of the turbine measured by the RPM measurer and a preset targeted value while a vehicle is in a coasting operation in an in gear state.

When a power transmission path of a power transmission system is set to a second power transmission path, a continuously variable transmission is controlled at a speed ratio () that provides a higher vehicle speed in the case where an input shaft angular acceleration (di/dt) is small than in the case where the input shaft angular acceleration (di/dt) is large. Therefore, it is possible to control the speed ratio () of the continuously variable transmission to a speed ratio () that reflects an inertial loss (Tli) of the continuously variable transmission. The inertial loss (Tli) changes with the input shaft angular acceleration (di/dt). Thus, in a vehicle in which the continuously variable transmission and a gear mechanism are provided in parallel with each other between an input shaft and an output shaft, it is possible to appropriately reduce a loss of the idling continuously variable transmission.

A device and method to detect and resolve a tooth-on-tooth situation of a gearbox (40) are provided. The device (20) includes at least one processing circuit (30) configured to obtain a gearbox actuator position (16) indicative of a position of an actuator member (52, 53) of a gearbox actuator (50). The at least one processing circuit (30) is configured to process the gearbox actuator position (62) to detect a tooth-on-tooth situation and to trigger a corrective procedure to resolve the tooth-on-tooth situation. The corrective procedure includes triggering, by the at least one processing circuit (30), a rotational speed pulse (67, 68) or several rotational speed pulses (67, 68) for an input shaft (45) of the gearbox (40) to resolve the tooth-on-tooth situation.