Methods and systems are provided for a dual motor electric transmission configured with two dual synchronizers to reduce torque interruption during gear shifting. In one example, a method may include dropping torque of a first electric motor, allowing a first synchronizer to shift from a first gear arrangement to a second gear arrangement, and compensating for dropped torque with a second electric motor. The method may be repeated to shift a second synchronizer from the first gear arrangement to the second gear arrangement, allowing uninterrupted torque supply during gear shifting.

A vehicle gear-shifting control apparatus is equipped with an engine, an automatic transmission, and a controller which changes a shift stage by outputting a gear-shifting signal in accordance with the rotation speed of an input shaft to the automatic transmission. The controller executes a torque-regulating control of temporarily increasing or decreasing an input torque input to the input shaft during a shift-change, and when executing the control, determines whether or not a target increase/decrease amount of the input torque can be realized based on calculation results of a target output torque and a target gear-shifting time, executes the control to realize the target amount when it is determined that the target amount can be realized, and executes the control based on an allowable gear-shifting time set in advance to be longer than the target gear-shifting time when it is determined that the target amount cannot be realized.

A control system (32, 33) for a vehicle (10), the control system (32, 33) comprising one or more controllers, the control system (32, 33) being configured to: receive a transmission speed signal that is indicative of an output speed of a transmission (24) of the vehicle (10) as the transmission (24) performs a gearshift; receive a driver demand signal that is indicative of a driver demand for acceleration of the vehicle (10) during the gearshift; and determine a torque demand signal for an engine (20) of the vehicle (10) in accordance with the transmission speed signal and the driver demand signal.

The present invention provides a shift control method include: setting a basic target synchronization rotation speed that is a basic target value of the input shaft rotation speed during the shift; determining whether or not an accelerating intention is present when the shift is a downshift with a driving force requirement to the vehicle; when the accelerating intention is present, setting a first target input shaft rotation speed as the target input shaft rotation speed, the first target input shaft rotation speed being obtained by increasingly correcting the basic target synchronization rotation speed; and when the accelerating intention is not present, setting a second target input shaft rotation speed as the target input shaft rotation speed, the second target input shaft rotation speed being obtained by maintaining or decreasingly correcting the basic target synchronization rotation speed.

An active shift control method for a power-off downshift of the hybrid vehicle is provided. The method includes increasing the torque of an engagement clutch in a transmission while disengaging a disengagement clutch by reducing the torque of the disengagement clutch in the transmission, when the shift of a power-off downshift is requested. A motor speed is adjust for a transmission input shaft rotary speed to reach a predetermined target stage synchronization speed of a target stage after shifting, and the torque of the engagement clutch is maintained in a state where the disengagement clutch has been disengaged. The engagement of the engagement clutch is completed by increasing the torque of the engagement clutch when the transmission input shaft rotary speed has reached the target stage synchronization speed.

A control device for an automatic transmission includes a traveling drive source, an automatic transmission, an AT controller, and a traveling drive source controller. The AT controller is configured to execute shifting by changeover of friction elements upon receiving a shift request. The traveling drive source controller is configured to execute torque limit control of the traveling drive source when a request for limiting a torque by an upper limit torque is input from the AT controller. The AT controller has an upper limit torque change processing unit configured to change the upper limit torque from a low gear upper limit torque to a high gear upper limit torque when auto-upshift is executed. The upper limit torque change processing unit is configured to raise the upper limit torque using a prescribed gradient during an inertia phase when the inertia phase is started with the auto-upshift.

A method and a system of learning a pressure applied to a brake of a countershaft may include determining, when a shift condition is satisfied, whether a shifting to be performed is a power off upshift; releasing a clutch mounted between a power source and the transmission when the shifting to be performed is the power off upshift; detecting a contact duration until a speed of an input shaft of the transmission is lowered by a predetermined speed by applying a target pressure stored in a memory to the brake of the countershaft when the release of the clutch is completed; comparing the contact duration with a predetermined duration; correcting, when the contact duration is greater than the predetermined duration, the target pressure according to a difference between the contact duration and the predetermined duration; and storing and updating the corrected target pressure in the memory to apply a subsequent power on upshift.

A control device for an automatic transmission includes a traveling drive source, an automatic transmission, an AT controller, and a traveling drive source controller. The AT controller is configured to execute shifting by changeover of friction elements upon receiving a shift request. The traveling drive source controller is configured to execute torque limit control of the traveling drive source when a request for limiting a torque by an upper limit torque is input from the AT controller. The AT controller has an upper limit torque change processing unit configured to change the upper limit torque from a low gear upper limit torque to a high gear upper limit torque when auto-upshift is executed. The upper limit torque change processing unit is configured to raise the upper limit torque using a prescribed gradient during an inertia phase when the inertia phase is started with the auto-upshift.

A control device of an automatic transmission to set and control a gear position based on a vehicle speed and an accelerator opening degree, includes a controller determining a high load travel based on a travel resistance during travel control on a gear shift line, which is set such that a region on a higher accelerator opening degree side of a downshift line is a region where a lock-up clutch is to be turned off, and turning off the lock-up clutch before downshifting when determining the high load travel.

A shift control method for a vehicle with a double clutch transmission (DCT) is configured such that when a power-on upshift is initiated, during a target time for a controller to perform a torque phase, a release-side clutch is gradually released, an engine torque is gradually increased to a basic engine torque or more, and an engagement-side clutch torque is increased according to an increase in the engine torque and a vehicle speed; and when the release-side clutch is completely released, the controller reduces the engine torque while gradually reducing the engagement-side clutch torque to be equal to the basic engine torque, to perform an inertia phase such that an engine speed is synchronized with an engagement-side clutch speed.