Systems and methods for operating an engine of a vehicle that may be automatically stopped and started are disclosed. In one example, a speed at which a vehicle system induced automatic engine stop inhibit request is cleared may be adjusted to permit automatic engine stopping during a wide variety of driving conditions so that fuel may be conserved and the possibility of disturbing vehicle occupants may be reduced.

A threshold that is used in determining, based on a deviation between slip amounts, whether to stop slip control or not during the performance of feedback control in slip control is made smaller when pitch damping control is being performed than when pitch damping control is not being performed, during the performance of slip control of a lockup clutch. Therefore, slip control is likely to be stopped when the torque input to the lockup clutch is likely to fluctuate. In consequence, a control apparatus and a control method for a vehicle that make it possible to stably perform slip control of the lockup clutch while increasing the number of opportunities to perform the slip control and pitch damping control are provided.

Systems and methods for operating an engine of a vehicle that may be automatically stopped and started are disclosed. In one example, a speed at which a vehicle system induced automatic engine stop inhibit request is cleared may be adjusted to permit automatic engine stopping during a wide variety of driving conditions so that fuel may be conserved and the possibility of disturbing vehicle occupants may be reduced.

A transmission gear control apparatus for a vehicle is provided. The vehicle includes an automatic transmission, a torque converter, and an accelerator operation amount sensor. The torque converter is disposed between the engine and the automatic transmission. The transmission gear control apparatus includes an electronic control unit. The electronic control unit is configured to: (i) control switching of a transmission gear stage of the automatic transmission at least on a basis of a change in vehicle speed of the vehicle; (ii) control lockup of a lock-up clutch of the torque converter on a basis of a state of the vehicle; and (iii) control the automatic transmission when the accelerator operation amount is equal to or larger than a specified value such that an upshift of the automatic transmission is performed at a higher vehicle speed as a rotation difference between input and output of the torque converter is reduced.

Systems and methods for improving operation of a hybrid vehicle are presented. In one example, compensation is provided for a dual mass flywheel positioned in a vehicle driveline. The approaches may reduce driveline torque disturbances.

Methods and systems are provided for adjusting powertrain torque in a vehicle based on driver intent. Driver intent is inferred based on foot motion inside a foot well monitored via a foot well region sensor and changes in clearance outside the vehicle monitored via a range sensor. By adjusting powertrain torque based on operator foot motion and traffic movements outside the vehicle, frequency of lash transitions can be reduced and lash transition initiation can be adjusted based on expected changes in torque demand.

Systems and methods for transitioning a torque source between speed control and torque control modes during a vehicle creep mode are disclosed. In one example, torque of an electric machine is adjusted in response to a torque converter model. The torque converter model provides for a locked or unlocked torque converter clutch.

Methods and systems are provided for adjusting powertrain torque in a vehicle based on driver intent. Driver intent is inferred based on foot motion inside a foot well monitored via a foot well region sensor and changes in clearance outside the vehicle monitored via a range sensor. By adjusting powertrain torque based on operator foot motion and traffic movements outside the vehicle, frequency of lash transitions can be reduced and lash transition initiation can be adjusted based on expected changes in torque demand.

A system includes an engine, a generator assembly, a direct current voltage bus, and a controller. The assembly is coupled to and driven via the engine, and has an electric generator, field windings, and a voltage rectifier collectively producing a generator output voltage. An inner control loop of the controller provides a field duty cycle signal to the field windings in response to an adjusted voltage control signal. An outer control loop of the controller provides a torque-based voltage control signal as an input to the inner control loop in response to a commanded engine torque and an estimated generator torque. An output torque of the generator is directly controlled via the outer control loop. The inner control loop calculates the adjusted voltage control signal as a difference between the torque-based voltage control signal and the output voltage.

A system and method for modifying the engine pull-up (EPU) logic within a hybrid vehicle based on max motor torque that accounts for the drop or change in available motor torque due to the opening/slipping of a torque converter bypass clutch during engine starts is disclosed. An engine pull-up threshold is determined from max available motor torque at a virtual impeller speed, where the virtual impeller speed is the impeller speed that would result if the torque converter bypass clutch was open/slipping and transferring the same amount of torque.