Abstract: A hybrid vehicle includes an engine and an electric machine selectively coupled to the engine via a disconnect clutch. At least one controller issues commands to control the engine, the electric machine, and the clutch. During cruise control, the controller controls the torque output of the engine and electric machine, as well as the slipping of the clutch, such that the speed of the vehicle is attempted to be maintained at the cruise control set speed. For example, when the engine is off and additional torque is necessary to maintain the speed, the controller can issue a command to change the state of the engine from off to on. When the vehicle experiences oscillations in road load, the controller delays or inhibits changing the on/off state of the engine for an amount of time that is based on the oscillation associated with road load.

Abstract: A parallel hybrid vehicle includes an engine and a motor separated along a driveshaft by a clutch. The motor can operate (either alone or in combination with the engine) to provide positive drive torque to the wheels. The motor can also act as a generator and provide negative torque when converting mechanical energy from the driveshaft into mechanical energy to be stored in a battery. The clutch selectively couples the motor to the engine. Torque and its effects on the clutch can vary dramatically when the motor changes from providing positive and negative torque, and vice versa, while the engine is running. At least one controller in the vehicle is programmed to, while the engine is running, initiate an increase in pressure at the clutch in response to an anticipated change in torque provided by the motor from positive to negative or from negative to positive.

Abstract: A method according to an exemplary aspect of the present disclosure includes, among other things, controlling a torque output of an electric machine of an electrified vehicle based on estimated loads present during a transmission engagement of the electrified vehicle.

Abstract: Impeller speed, which is difficult to measure when a torque converter includes an impeller clutch, is estimated based on a known relationship among impeller speed, turbine speed, and turbine torque. Turbine torque may be directly measured by a turbine torque sensor or estimated based on other measurements such as output shaft torque or vehicle acceleration. The relationship is stored in a controller in terms of the coefficients of a second order polynomial relating turbine torque to impeller speed and turbine speed. A slip speed is calculated based on a measured input shaft speed and the estimated impeller speed. Closed loop control is used to adjust the impeller clutch torque capacity to maintain a target slip.

Abstract: A control system including a method and apparatus for operating a hybrid vehicle. A disconnect clutch selectively separates an electric machine from a combustion engine. If a wide open throttle or high torque command is requested and the combustion engine is shut down, a 12 volt starter may be used to start the combustion engine while disconnected from the electric machine and all of the electric machine torque available may be used for traction.

Abstract: A vehicle includes an engine, a traction motor, a clutch, and a controller. The clutch selectively couples the traction motor to wheels. The controller, in response to a torque output by the fraction motor achieving a torque limit while operating to partially satisfy a demand for driveline damping and while the clutch is locked, slips the clutch to completely satisfy the demand for driveline damping.

Abstract: Systems and methods for improving transmission gear shifting of a hybrid vehicle are presented. The systems and methods prepare the hybrid vehicle for conditions that may occur after a requested gear shift is performed. In one example, a motor speed that would occur after a downshift, if the downshift were allowed to occur, is determined and control actions may be taken in response to the predicted motor speed.

Abstract: Methods and systems are provided for improving engine restart operations in a hybrid vehicle. While an engine is cranked via motor torque, engine fueling is delayed until the engine speed is sufficiently high and the engine has been rotating in a forward direction continuously for a threshold duration. A disconnect clutch between the engine and motor is slipped while the engine cranks, the clutch engaged only after the engine has run up to the motor speed.

Abstract: Systems and methods for starting an engine of a hybrid vehicle are disclosed. The systems and methods disclosed may apply to series or parallel hybrid driveline configurations. In one example, engine cranking torque may be adjusted in response to a variety of operating conditions so that the engine may be started faster or slower.

Abstract: Systems and methods for improving operation of a driveline disconnect clutch for a hybrid vehicle shifting are presented. In one example, pressure of a working fluid supplied to the driveline disconnect clutch is adjusted in response to a rate of change in accelerator pedal position. Further, pressure of the working fluid may be decreased responsive to selected operating conditions.

Abstract: Systems and methods for improving hybrid vehicle shifting are presented. Specifically, torque supplied to an input shaft of a transmission may be adjusted during torque and inertia phases of a transmission gear shift. The torque supplied to the transmission input shaft may be increased or decreased based on the shift and the shift phase.

Abstract: A method of starting a vehicle may include providing power to a motor to spin the motor at a speed at least equal to a target engine cranking speed while a clutch configured to couple an engine and motor is open. The method may also include cutting power to the motor in response to the motor achieving the speed, and locking the clutch to couple the rotating inertias of the motor and a transmission with the engine to start the engine.

Abstract: Impeller speed, which is difficult to measure when a torque converter includes an impeller clutch, is estimated based on a known relationship among impeller speed, turbine speed, and turbine torque. Turbine torque may be directly measured by a turbine torque sensor or estimated based on other measurements such as output shaft torque or vehicle acceleration. The relationship is stored in a controller in terms of the coefficients of a second order polynomial relating turbine torque to impeller speed and turbine speed. A slip speed is calculated based on a measured input shaft speed and the estimated impeller speed. Closed loop control is used to adjust the impeller clutch torque capacity to maintain a target slip.

Abstract: Methods and systems for controlling a transmission coupled to an engine during an engine start are presented. In one example, a method adjusts a transmission tie-up force in response to an indication of transmission slip. The method may improve vehicle launch for stop/start vehicles.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, compensation for a driveline disconnect clutch is provided. The approaches may reduce driveline torque disturbances.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, application of a driveline disconnect clutch to start an engine is described. The approach applies the driveline disconnect clutch to rotate an engine and at least partially disengages the driveline disconnect clutch to reduce the possibility of a reduction in torque applied to vehicle wheels.

Abstract: An individual driving value is set as a function of an accelerator pedal position. In turn, a powertrain characteristic is set as a function of the individual driving style. The set powertrain characteristic may be modified on the basis of a feedback value corresponding to learned preferences of a driver. The modified powertrain characteristic is then either automatically implemented for operation of a powertrain or communicated as a choice for implementation. The feedback value is updated per a response to automatic implementation or choice communication.

Abstract: Methods and systems are provided for reducing audible clunks and objectionable drive feel in vehicles including start/stop systems. In one example, a vehicle engine is shutdown during vehicle coasting. The vehicle engine is then restarted, while the vehicle is moving with a torque converter clutch disengaged. A transmission clutch pressure is then adjusted during the restart based on a torque converter output speed relative to a torque converter input speed.

Abstract: A method for controlling vehicle regenerative braking includes decreasing regenerative braking, provided a converter clutch is locked, such that regenerative braking torque reaches zero before a converter clutch opens due to vehicle speed reaching a reference speed; decreasing regenerative braking, provided the converter clutch is scheduled to open, such that regenerative braking torque reaches zero before the converter clutch opens due to vehicle speed reaching the reference speed; and braking the vehicle using wheel brakes.

Abstract: Methods and systems are provided for restarting an engine in response to a driver's change-of-mind. In one embodiment, the engine is shutdown during an idle stop with the transmission in a higher gear or with the transmission tied-up to a transmission case. In response to a driver change-of-mind restart request, the transmission is downshifted, or released from the tie-up, to return driveline torque.