A lockup control device for a vehicle includes: a torque converter, and a lockup control configured to increase a lockup pressure difference command to an initial pressure difference, when a turbine rotation speed variation amount of the torque converter becomes smaller than a predetermined value during a ramp control in which the lockup pressure difference command is increased by a ramp pressure difference, the lockup control section being configured to switch to a second increase gradient having an increase gradient lower than a first increase gradient of the ramp pressure difference when the turbine rotation speed variation amount is equal to or greater than the predetermined value.

A lockup control device for a vehicle includes: a torque converter, and a lockup control configured to increase a lockup pressure difference command to an initial pressure difference, when a turbine rotation speed variation amount of the torque converter becomes smaller than a predetermined value during a ramp control in which the lockup pressure difference command is increased by a ramp pressure difference, the lockup control section being configured to switch to a second increase gradient having an increase gradient lower than a first increase gradient of the ramp pressure difference when the turbine rotation speed variation amount is equal to or greater than the predetermined value.

A work vehicle includes a torque converter having a lock up clutch and a controller that conditionally allows operation of the lock up clutch in a locked position or an unlocked position. The controller determines a plurality of active work vehicle parameters during operation of the work vehicle and includes a plurality of ready to dig parameters. The controller determines a ready to dig condition or a non-digging condition of the work vehicle by comparing at least two of the active work vehicle parameters to at least two corresponding ready to dig parameters. The controller disallows operation of the lock up clutch in the locked position in response to the ready to dig condition, allows operation of the lock up clutch in locked or unlocked positions in response to a non-digging condition. Operation of the lock up clutch avoids the engine from stalling in a ready to dig condition.

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 controlling a machine impeller clutch includes a power source, a transmission unit, an impeller clutch operatively coupling the power source to the transmission unit, and an input device configured to generate a force data signal indicative of a working fluid pressure. An electronic control module in communication with the input device is configured to execute a time-step predictive analytical model for impeller clutch engagement. The electronic control module configured to receive the force data from the input device, determine an impeller clutch engagement value based at least in part on the force data signal and utilizing the time-step predictive analytical model, and cause engagement of the machine impeller clutch according to the impeller clutch engagement value.

A control system to control slip of a torque converter clutch includes a clutch plant model configured to predict a value of a parameter that relates to torque converter clutch slip as a function of clutch plant model inputs comprising commanded clutch pressure and of torque from the torque generative device. The control system also includes a model predictive controller configured to receive signals that allow determination of a desired value of the parameter that relates to torque converter clutch slip and a predicted value of the parameter that relates to torque converter clutch slip, receive a signal representing reported torque of the torque generative device, identify an optimal commanded clutch pressure value that will result in an optimal value of an objective function based on the clutch plant model, and provide a command signal to an actuator effective to control commanded clutch pressure to the torque converter clutch.

A control device for an automatic transmission of a vehicle includes a shift control section including; a deceleration state judging section configured to judge whether a deceleration of the vehicle is a gentle deceleration state or a sudden deceleration state, and a downshift control section configured to command a plural stage downshift to downshift from a current shift stage of the automatic shift mechanism to a target shift stage that is lower than the current shift stage by two stages or more when the deceleration state judging section judges the sudden deceleration state.

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 hydraulic pressure supply system includes a mechanical oil pump, an electric oil pump, a first flow path, a second flow path, and a cut-off mechanism. The mechanical oil pump is configured to operate by power from an engine. The electric oil pump is configured to operate by power from a motor. In the first flow path, oil supplied from the mechanical oil pump and the electric oil pump flows, the first flow path being coupled to the mechanical oil pump and the electric oil pump. The second flow path branches off from the first flow path and is configured to cause an oil to return to an oil pan via a torque converter. The cut-off mechanism is configured to close off the second flow path by oil delivered from the electric oil pump.

A method for operating a drive train of a motor vehicle includes selecting between first and second operating strategies for controlling a starting component (3A, 3B) during a stopping process of the motor vehicle, and carrying out a downshift of the transmission (G) during the stopping process after implementing the first operating strategy or the second operating strategy. In the first operating strategy, the starting component (3A, 3B) is engaged or locked up and/or remains engaged or locked up at least until the motor vehicle comes to a standstill. In the second operating strategy, the starting component (3A, 3B) is disengaged or the lock-up of the starting component (3A, 36) is released before the motor vehicle come to the standstill. The downshift of the transmission (G) is triggered at a different rotational speed limit value upon implementation of the first operating strategy than upon implementation of the second operating strategy.