A shift control device for establishing a desired gear stage promptly while reducing a shock, during propulsion while disengaging all of engagement devices of a transmission. The shift control system compares a target stage set based on an operating data to an interim stage set based on the operating data immediately before the target stage is set. If the target stage is lower than the initial stage the engagement devices are engaged to establish the target stage without establishing the initial stage.

When a jump downshift via an intermediate shift stage is requested and a rotation speed of an input shaft approaches a synchronous rotation speed of the intermediate shift stage, a target torque phase time when the gear shift via the intermediate shift stage is performed with input switching is set to be shorter than that when the gear shift via the intermediate shift stage is performed without using input switching and torque phase control is performed. Accordingly, it is possible to promptly perform engagement of an engagement-side frictional engagement element at the time of passing through the intermediate shift stage and to rapidly perform the gear shift after passing through the intermediate shift stage.

In a controller for an automatic transmission, when a jump gear shift via a plurality of intermediate shift stages is executed, a first and a second target intermediate shift stages are extracted, and a target input shaft rotation speed change rate is calculated from a difference in synchronous rotation speed between a shift stage before a current gear shift and the second target intermediate shift stage as a target shift stage of a gear shift which is executed after the current gear shift. Accordingly, it is possible to avoid a situation in which a shifting time in the gear shift control of the step before the second target intermediate shift stage becomes very short and thus packing of a clutch pack is not executed in a timely manner.

Methods and systems are provided for performing a multiple gear downshift of a transmission gear by transiently operating in an intermediate gear. In response to ambient humidity and a condensate level in a charge air cooler, the transmission gear may be downshifted from a higher gear to an intermediate gear, and then to a requested lower gear. Downshifting through an intermediate gear may also be controlled based on the gear shift request.

A motor vehicle having a drive unit, the power output shaft of which outputs alternately to a first sub-transmission or a second sub-transmission of a dual clutch transmission by way of two separating clutches of a dual clutch. The first sub-transmission has the odd-numbered forward gears and the second sub-transmission has the even-numbered forward gears, and having a transmission control device, which has a driving strategy unit for determining a target gear as a function of input parameters and a shift sequence control unit, with which a gear change from the current gear to the target gear can be controlled.

When there is a request for a skip downshift that transitionally establishes an intermediate speed position, a surge hydraulic pressure at the start of a torque phase during shift control toward the intermediate speed position is set so as to be lower than a surge hydraulic pressure at the start of a torque phase during shift control toward a required speed position.

A DCT shifting control method of a vehicle includes: a temporary engaging step that engages an N-3 stage gear having a gear ratio larger than an N stage gear that is a currently engaged gear; a first torque switching step that starts to slip a first clutch engaged with the N-3 stage gear and disengages a second clutch engaged with the N stage gear that is the currently engaged gear; a synchronization speed adjusting step that synchronizes a speed of a power source of a vehicle with a desired input shaft speed by controlling the power source of the vehicle, disengages the N stage gear, and engages the N-2 stage gear that is the desired gear, with the slip of the first clutch maintained; and a second torque switching step that finishes shifting by disengaging the first clutch and engaging the second clutch.

An automatic transmission controller is provided, which is capable of reducing occurrence of a shift shock while improving responsiveness of a driving force. An ECU is configured to calculate a target shift time based on an input torque that is input to the automatic transmission when a gear stage is shifted from a current gear stage to a target gear stage spaced two or more stages apart from the current gear stage. The ECU is also configured to: shift the gear stage to an intermediate gear stage between the current gear stage and the target gear stage when the target shift time is not less than a predetermined value; and to shift the gear stage directly to the target gear stage when the target shift time is less than the predetermined value.

An automatic transmission control device is configured to execute a first shifting between a pre-shifting gear position and an intermediate gear position, and a second shifting between the intermediate gear position and a post-shifting gear position such that each of the first and second shiftings is executed by releasing one of engagement devices and engaging one of the engagement devices, and is configured, upon transition from the first shifting to the second transition, to gradually changing an engagement torque of an engagement-maintained engagement device as one of the engagement devices which is engaged upon completion of the first shifting and is maintained in the engaged state during the second shifting, such that the engagement torque of the engagement-maintained engagement device is changed gradually from a required engagement torque required upon completion of the first shifting, to a required engagement torque which is required in the second shifting.

A gear shift mechanism controlled by a gear shift control device includes a plurality of engagement mechanisms and engages three engagement mechanisms to establish any one of a plurality of shift stages. The gear shift control device is adapted to change speed to a desired shift stage set by a manual operation. If a gear shift to the desired shift stage involves the skipping of one or more shift stages and the switching of two or more engagement mechanisms among the plurality of engagement mechanisms that are currently engaged, then the gear shift control device performs the gear shift to the desired shift stage such that the engagement mechanisms to be switched via a shift stage or stages to be skipped are switched one by one.