Abstract:
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.
Abstract:
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.
Abstract:
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 (γ) that provides a higher vehicle speed in the case where an input shaft angular acceleration (dωi/dt) is small than in the case where the input shaft angular acceleration (dωi/dt) is large. Therefore, it is possible to control the speed ratio (γ) of the continuously variable transmission to a speed ratio (γ) that reflects an inertial loss (Tli) of the continuously variable transmission. The inertial loss (Tli) changes with the input shaft angular acceleration (dωi/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.
Abstract:
A speed change control system for reducing shift shocks of clutch-to-clutch shifting is provided. The control system is applied to a vehicle in which a transmission having engagement devices is connected to an output side of a prime mover, and in which a gear stage of the transmission is shifted among a plurality of stages by changing engagement states of the engagement devices. The speed change control system carries out a clutch-to-clutch shifting from a predetermined gear stage to another gear stage by reducing a torque capacity of the predetermined engagement device to be disengaged while increasing a torque capacity of another engagement device to be engaged.
Abstract:
A method of identifying a synchronous position of a synchronizer actuator fork includes sensing a deceleration rate of a first shaft, when a synchronizer is positioned in a neutral position, to define a first rate of deceleration. The synchronizer is moved along the first shaft from the neutral position toward a gear with a synchronizer actuator fork. A deceleration rate of the first shaft is sensed, while the synchronizer actuator fork moves the synchronizer along the first shaft, to identify a change from the first rate of deceleration to a second rate of deceleration. The location, of the synchronizer actuator fork relative to the first shaft, at which the rate of acceleration of the first shaft changes from the first rate of deceleration to the second rate of deceleration, is identified as the synchronous position of the synchronizer actuator fork.
Abstract:
A system and method for regulating torque transmitted via a torque converter can include providing a lock up clutch between a crankshaft and transmission of a vehicle. A position sensor can output data indicative of at least one of an engaged position of the lock-up clutch, a transitional position of the lock-up clutch, and a disengaged position of the lock-up clutch. An engine speed sensor can output data indicative of rotational speed of the crankshaft. A controller can be placed in electrical communication with the engine speed sensor and the position sensor and configured to determine when actuation of the lock-up clutch is desired. The controller can be configured to determine a torque reduction target based on certain variables, for example, engine acceleration. The controller can then signal the engine to output torque substantially equal to the torque reduction target when conditions exist that warrant torque reduction.
Abstract:
A coast stop vehicle which executes coast stop control for stopping an engine during the travel of a vehicle, is provided with a frictional engagement element provided between the engine and a driving wheel, a first deceleration calculating unit which calculates first deceleration, which is rotation deceleration of a rotation shaft on the driving wheel side of the frictional engagement element, and an engagement-state control unit which controls an engagement state of the frictional engagement element so that decrease of the engine rotation speed is suppressed on the basis of the first deceleration while the coast stop control is executed.
Abstract:
A dynamic model that is configured to produce a lockup clutch command as a function of a plurality of torque converter operating parameters is continually solved and the lockup clutch command is asserted to control engagement of the lockup clutch. A profile of one of the plurality of torque converter operating parameters is selected and is configured, when inserted into the model in place of an actual value thereof, to result in an intersection of rotational speeds of the pump and the turbine over time. Deceleration of the pump is monitored after asserting the lockup clutch command and a maximum deceleration of the pump is determined therefrom. The selected profile is temporarily held constant if the monitored deceleration of the pump rises at least a threshold value above the maximum deceleration of the pump.
Abstract:
A method of operating a transmission device comprising friction-locking and form-locking shift elements for obtaining different gear ratios. A shift request for engaging a shift element undergoes a time delay dependent upon an operating state prior to a time of engagement of the shift element. A rotational speed differential between halves of the shift element lies within a rotational speed differential window required for the engagement procedure is assigned to the time of engagement. A gradient of the transmission input speed is ascertained at the time of the shift request, and the actual gradient is subsequently monitored and compared with the gradient that existed at the time of the shift request. If an absolute deviation greater than a threshold value is ascertained, the time delay is changed or an actuation of another shift element to be disengaged is varied such that the deviation is reduced below the threshold value.
Abstract:
A control system in a vehicle in which at least one pair of driving power transmission members are engaged with each other with a slack on a driving power transmission path, comprises an input shaft rotational speed detector for detecting a rotational speed of an input shaft located upstream of engaged portions of the driving power transmission members in a direction in which the driving power is transmitted, a determiner for determining whether or not the driving power transmission members are in a non-contact state at the engaged portions for a period of time based on a change rate of the detected input shaft rotational speed, and a controller for controlling the vehicle to reduce a rotational speed difference between the input shaft and an output shaft located downstream of the engaged portions, when the determiner determines that the driving power transmission members are in the non-contact state.