Abstract: A vehicle includes an engine, an electric machine, a battery, and at least one controller. The vehicle may further comprise a port for supplying power to a load external to the vehicle. The controller is programmed to operate the engine at a power level based on a difference between a battery voltage and a reference voltage such that a power output by the electric machine reduces the difference. The power level may define an engine operating point that minimizes fuel consumption. The operating point may be an engine torque and an engine speed. The power level may be further based on a state of charge of the battery. The electric machine may be operated to cause the engine to rotate at an engine speed corresponding to the selected power level. The difference may be caused by varying power drawn by a load external to the vehicle.

Abstract: An autonomous vehicle controller includes a memory and a processor programmed to execute instructions stored in the memory. The instructions include determining a plurality of energy cost functions. Each energy cost function is associated with a combination of candidate variables. The instructions further include selecting one of the plurality of energy cost functions as a minimum energy cost function, determining a combination of candidate variables associated with the minimum energy cost function, and controlling acceleration of a host vehicle according to the combination of candidate variables associated with the minimum energy cost function.

Abstract: A vehicle powertrain includes a controller, a torque converter, and an engine and electric machine coupled by a clutch. The torque converter may be configured to couple the electric machine to an output shaft. The controller may be programed to generate a command for the electric machine to output torque to drive the torque converter toward a desired rotational speed, and to modify the command according to a difference between the desired rotational speed and an actual rotational speed to reduce the difference, wherein values of the difference are limited by thresholds that change with powertrain operation.

Abstract: A table of engine torque correction factors is used to compensate for noise factors. In a hybrid vehicle, the motor is used to measure engine torque during periods of constant transmission input shaft torque. By comparing the measured input torque to the requested engine torque, a controller can update the table of correction factors to compensate for changes in the noise factors. A service procedure may be implemented that systematically provides the controller an opportunity to update many values in the table.

Abstract: Systems and methods for operating a hybrid vehicle driveline that includes an engine and a motor are presented. In one example, the systems and methods include one or more speed control modes where torque output of a motor is adjusted responsive to different control parameters in the different control modes.

Abstract: A vehicle comprises a hybrid powertrain includes an electric machine coupled between an automatic gearbox and an engine. The vehicle includes paddle shifters configured to output a driver requested gear change. The hybrid powertrain is configured to selectively operate in an economy mode that optimizes fuel economy. While operating in the economy mode, a controller may selectively inhibit the driver requested gear change when the change may negatively impact fuel economy. In the economy mode, the driver requested gear change may be inhibited during a demand for braking. If the driver requested gear change is a downshift request, the downshift is inhibited and simulated using electric machine torque.

Abstract: A vehicle includes a step-ratio automatic transmission having clutches engageable to provide forward and reverse gears, an electric machine selectively coupled to the transmission, a main pump powered by the electric machine and supplying oil to actuate selected transmission clutches, a gear selector configured for selecting a transmission gear, and a controller configured to stop the electric machine when the gear selector selects park or neutral, to operate the electric machine in a speed control mode using a higher controller gain in response to the gear selector selecting forward or reverse while the electric machine is stopped until the electric machine and the main pump reach a first speed threshold to reduce engagement delay of at least one of the transmission clutches, and to operate the electric machine using a lower controller gain when the electric machine and the main pump exceed the first speed threshold.

Abstract: Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods adjust torque converter clutch opening responsive to whether or not a motor/generator is available to provide a negative torque to a driveline. Further, the motor/generator and the vehicle's engine are operated to provide a desired amount of driveline braking.

Abstract: Methods and systems are provided for operating a hybrid vehicle during operating conditions where vehicle braking is requested. In one example, regenerative braking is permitted during conditions of wheel slip so that a greater portion of a vehicle's kinetic energy may be recovered and stored as electrical energy. Additionally, the amount of regenerative braking may be adjusted responsive to a torque of a differential clutch during wheel slip conditions.

Abstract: A shift strategy is provided for a hybrid electric vehicle to cause a speed of a motor to approach a target motor speed to increase fuel economy for an engine operating in a hybrid drive mode. A controller shifts the transmission according to a magnitude of a driver torque demand, the current rotor or impeller speed, and whether the motor is consuming or producing current. The controller shifts the transmission according to one shift schedule when the motor is motoring, and according to another shift schedule when the motor is generating power.

Abstract: A hybrid powertrain includes a traction battery and a controller. The controller is programmed to, responsive to a current vehicle speed exceeding a first threshold, reduce a parameter indicative of state of charge (SOC) of the battery by an offset amount that varies with an amount of predicted distance for which a predicted vehicle speed profile is less than a second threshold to prompt charging of the battery to increased SOC values.

Abstract: A vehicle includes a motor and a controller. The controller is programmed to, responsive to an autonomous braking request and a predicted average braking torque associated with the request having a magnitude less than a powertrain regenerative torque limit, brake the vehicle only with the motor according to a torque profile adapted from a most efficient torque profile of the motor so as to have an average value falling within a specified range of the average braking torque.

Abstract: A vehicle includes an engine and an electric machine coupled to a gearbox through a torque converter. The vehicle includes a controller programmed to command an engine torque and an electric machine torque to achieve a predetermined positive torque at the input of the torque converter when a driver demand torque at the torque converter input decreases to fall within a range between the predetermined positive torque and a predetermined negative torque.

Abstract: Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, a rear drive unit electric machine, an integrated starter/generator, and a transmission are described. In one example, charging of an electric energy storage device may be allocated between the rear drive unit electric machine and the integrated starter/generator to increase charge stored in the electric energy storage device.

Abstract: A vehicle system may include a controller configured to increase, after a specified delay, an engagement pressure of a torque converter clutch prior to occurrence of the event to a target pressure that is based on a regenerative braking torque estimate associated with the event such that a portion of energy associated with the event is converted to electricity. The controller may increase the engagement pressure in response to an accelerator pedal release and an expected regenerative braking event.

Abstract: A vehicle may include a controller configured to, in response to an accelerator pedal release and an expected regenerative braking event, increase an engagement pressure of a torque converter clutch prior to occurrence of the event to a threshold that is based on a regenerative braking torque estimate associated with the event such that during the event, the clutch transfers more torque than the converter.

Abstract: Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, gears of a transmission may be unlocked from layshafts while an engine is stopped to conserve energy. Alternatively, the gears may be locked and unlocked from layshafts in response to vehicle operating conditions while the engine is stopped to improve driveline response.

Abstract: An autonomous or semi-autonomous vehicle is provided that is capable of braking itself without a driver depressing the brake pedal. The vehicle has a powertrain that includes an engine, a transmission, and a motor with a connected battery to provide regenerative braking capabilities. Friction brakes are provided to apply when necessary, such as when the battery has a high state of charge and further regenerative braking would overcharge the battery. The braking may be activated in response to a sensor detecting a distance to an object in front of the vehicle. A vehicle controller is programmed to automatically control amounts of regenerative braking and friction braking during a braking event based on a comparison between a regenerative torque limit of the powertrain and a desired brake torque over the brake event to safely brake the vehicle during the brake event.

Abstract: A hybrid electric vehicle includes an engine, an electric machine, and a battery, coupled to a controller(s) configured to, in response to a virtual-driver signal, predict and maintain a constant-speed from a plurality of candidate speeds, to have a lowest fuel consumption and a minimum number of battery-charge-cycles, for a predicted distance and wheel-torque-power. A predicted engine-power is established from the wheel-torque-power required to maintain the constant-speed, and to power vehicle accessories and battery charging, such that fuel consumption and battery-charge-cycles are minimized over the predicted distance at the constant-speed. The controller(s) are configured to generate the predicted distance, from one or more of position and moving-map sensors, by detecting a current location, and identifying an open-road distance between the current location and at least one detected and/or predetermined way-point.

Abstract: A vehicle powertrain includes a controller, a torque converter, and an engine and electric machine coupled by a clutch. The torque converter may be configured to couple the electric machine to an output shaft. The controller may be programed to generate a command for the electric machine to output torque to drive the torque converter toward a desired rotational speed, and to modify the command according to a difference between the desired rotational speed and an actual rotational speed to reduce the difference, wherein values of the difference are limited by thresholds that change with powertrain operation.