A method of operating a vehicle includes, responsive to a command to launch the vehicle and while the vehicle is in a first gear, determining, at a controller, a feedforward component including a target engine torque and a target bypass clutch torque, and a feedback component that is based on an error between the target converter slip and a measured converter slip and between the target wheel torque and a measured wheel torque. The method further includes changing a commanded engine torque and a commanded bypass clutch torque based on the feedforward component and the feedback component.

A method of operating a vehicle includes, responsive to a command to launch the vehicle and while the vehicle is in a first gear, determining, at a controller, a feedforward component including a target engine torque and a target bypass clutch torque, and a feedback component that is based on an error between the target converter slip and a measured converter slip and between the target wheel torque and a measured wheel torque. The method further includes changing a commanded engine torque and a commanded bypass clutch torque based on the feedforward component and the feedback component.

A system for determining a torque converter clutch is stuck in an engaged position includes a control module, an engine speed sensor, and a transmission speed sensor. The control module evaluates the torque converter clutch by determining a value of a torque converter clutch command. The torque converter clutch command indicates a position of the torque converter clutch. In response to determining that the value of the torque converter clutch command indicates the disengaged position, the control module calculates accumulated slip based on the transmission speed and the engine speed during an evaluation time. In response to determining the evaluation time is complete, the control module compares the accumulated slip with a calibrated threshold of slip. In response to the accumulated slip being less than or equal to the calibrated threshold of slip, the control module determines the torque converter clutch is stuck in the engaged position.

There is provided a brake assembly structure for a transmission. An automatic transmission includes a torque converter, a transmission case, and a two-way clutch and a first brake which are accommodated in the transmission case and adjacent to each other. The first brake includes a drum, an outer plate that is fixed to the drum in such a manner that the outer plate is unrotatable with respect to the drum, an inner disk that comes in contact with the outer plate in an axial direction, and a hub to which the inner disk is fixed in such a manner that relative rotation is not permitted. The drum is provided separately from the transmission case and includes a hydraulic chamber. The two-way clutch is assembled in the transmission case and the first brake is then assembled in the transmission case.

A lockup control device for a vehicle includes: a torque converter; a lockup control section configured to increase a lockup pressure difference command to an initial pressure difference when a lockup engagement condition is satisfied in a disengagement state of the lockup clutch, and then to increase the lockup pressure difference command by a ramp pressure difference by a predetermined gradient, the lockup control section being configured to determine a ramp start condition by which the lockup pressure difference command is switched from the initial pressure difference to the ramp pressure difference, based on a speed ratio which is a ratio of input and output rotation speeds of the torque converter.

A first clutch, a first planetary gear mechanism, a second planetary gear mechanism, a third planetary gear mechanism, a fourth planetary gear mechanism, and a third clutch are arranged along an input shaft in that order from a driving source. The input shaft includes first and second input shafts that are coaxially connected together through a first spline engagement portion and capable of being separated from each other in an axial direction. The first spline engagement portion is disposed between the first clutch and a first element of the third planetary gear mechanism on the input shaft. The first clutch is connected to the first input shaft. The first element of the third planetary gear mechanism and the third clutch are connected to the second input shaft. The first element of the third planetary gear mechanism is removably connected to the second input shaft through a second spline engagement portion.

A control device for a lock-up clutch includes a control unit, an abnormality determination unit, a release control unit and a prohibition unit. The control unit is configured to control an engagement state of a lock-up clutch, and to perform a slip lock-up control by performing a feedback control of an engagement hydraulic pressure to be a first slip amount during coasting. The abnormality determination unit is configured to determine an abnormality when a state continues with a slip amount being equal to or greater than a second slip amount. The release control unit is configured to release the lock-up clutch when the abnormality is determined. The prohibition unit is configured to allow the control unit to raise the engagement hydraulic pressure by a prescribed pressure, and to prohibit determination by the abnormality determination unit, when the transmission ratio is downshifted during coasting while the slip lock-up control is performed.

A control apparatus of an automatic transmission, which includes a mechanical engaging mechanism functioning as a brake, includes a determination unit determining, when a selected gear is a lowest forward speed gear, and the mechanism is in a second state, whether to switch the mechanism to the first state, and a switching processing unit switching the mechanism to the first state based on a determination result. In the first state, only rotation of a predetermined rotational element provided in planetary gear mechanisms in a first direction is restricted. In the second state, rotation of the predetermined rotational element in both the first and second direction is restricted. The determination unit determines to switch the mechanism to the first state at least on condition that a driving force is larger than a predetermined driving force.

Ideally, when a transmission is in Neutral, no torque should be exerted on the vehicle wheels by the powertrain. However, even with all clutches in a gearbox disengaged, some torque may be transmitted from a turbine shaft to the transmission output due to clutch drag and transmission component inertia. To avoid transmitting torque, a subset of clutches may be engaged to produce an input tie-up state, this holding the turbine shaft against rotation while permitting rotation of the output element.

A method for controlling a vehicle installed with an automatic transmission, includes: a sudden stop determination step in which a controller determines whether the vehicle has stopped at a speed greater than or equal to a reference deceleration speed and whether a post-stop elapsed time is within a first reference time; a takeoff determination step in which the controller determines whether an input torque of the transmission exceeds zero within the first reference time when a shift range is in a driving range; a pressure control step in which, when the vehicle takes off, the controller elevates a line pressure of the transmission; a limitation determination step in which if a slippage extent of a turbine exceeds a reference slippage value for a second reference time, the controller limits the takeoff; and a torque reduction step in which the controller reduces a takeoff torque input of the transmission.