Abstract: A vehicle includes a drive wheel, an engine, an accelerator pedal, a torque converter, a clutch, and a controller. The drive wheel is configured to propel the vehicle. The engine is configured to generate power and to deliver power to the drive wheel to accelerate the vehicle. The accelerator pedal is configured to generate an acceleration request based on a pedal position. The torque converter is disposed between the engine and the drive wheel. The clutch is disposed between the engine and the drive wheel and is configured to bypass the torque converter. The controller is programmed to, in response to depressing the accelerator pedal to a position that corresponds with accelerating the vehicle at a desired magnitude, adjust the torque of the engine to accelerate the vehicle at the desired magnitude, regardless of the state of the clutch.

Abstract: A method for operating a vehicle that may be automatically stopped and started is described. In one example, the method includes starting an engine via expansion stroke combustion in response to a request to urgently start the engine. In addition, the method includes adjusting a position of a compression relief valve in response to a predicted urgency of an engine start.

Abstract: A hybrid electric vehicle or a battery electric vehicle has an electric machine, a traction battery, and an accessory powered by the traction battery. The vehicle includes a controller that, in response to a driver lifting their foot off the accelerator pedal, increases the negative motor torque produced by the electric machine for charging the traction battery to compensate for a load applied by the accessory. The controller increases negative motor torque as limited by a maximum motor torque limit. The accessory may be an electric air conditioning compressor and/or a DC/DC inverter.

Abstract: A method and system for operating a vehicle that includes an electric machine and an internal combustion engine is described. In one example, the method includes arbitrating between providing torque compensation to a driveline via an internal combustion engine or via an electric machine to improve transmission gear shifting. The method may consider a plurality of vehicle operating conditions to aid the arbitration.

Abstract: A method for operating a vehicle that includes a driveline disconnect clutch is described. In one example, the method adjusts torque of an electric machine in response to a estimated torque capacity of the driveline disconnect clutch. The estimated torque capacity of the driveline disconnect clutch is based on a combined inertia of a dual mass flywheel and the driveline disconnect clutch.

Abstract: A vehicle includes controller programmed to receive a driver-demanded wheel torque command and calculate a shaped wheel torque command based on the driver-demanded wheel torque command. The controller is further programmed to, in response to the driver-demanded wheel torque command changing from a first magnitude that is greater than an estimated wheel torque at a last time step to a second magnitude that is less than the estimated wheel torque at a current time step, set the shaped wheel torque to a minimum of a magnitude of the shaped wheel torque at the last time step and an estimated wheel torque at the current time step. The controller is also programmed to command the first and second actuators to produce the shaped wheel torque.

Abstract: Methods and systems are provided for operating a driveline of a four wheel drive vehicle that includes a high gear ratio and a low gear ratio. The driveline may be operated to shift between the high gear ratio and the low gear ratio while the four wheel drive vehicle is moving. In one example, a clutch is opened during shifting from the high gear ratio to the low gear ratio, which allows the vehicle to continue traveling during the gear ratio change.

Abstract: A vehicle operating method comprising generating a base torque reserve for an engine based on a position of an accelerator pedal and a position rate of change of the accelerator pedal, where the base torque reserve is an air reserve of the engine generated by the engine. The base torque reserve may further be generated based on one or more of a drive mode, a vehicle altitude, a battery state of charge (SOC), and a transmission gear, in at least one example.

Abstract: Methods and systems for operating a driveline that includes one or more electric machine providing torque to one or more axles are described. In one example, a requested vehicle speed is adjusted responsive to at least one of vehicle yaw, vehicle roll, and vehicle pitch so that vehicle speed may be maintained at a requested value.

Abstract: Methods and systems are provided for estimating a maximum available torque reserve prior to a gear upshift and then during the upshift, generating the torque reserve to fill a torque hole. In one example, a method may include estimating a maximum torque reserve based on each of a driver torque demand, an auxiliary system demand, and a maximum generable engine torque and then opportunistically generating the torque reserve.

Abstract: Systems and methods for operating a vehicle that includes an engine and an electric machine are described. In one example, electric machine torque is adjusted according to a wheel torque in a wheel torque creep mode where an engine provides torque to vehicle wheels. Operating the electric machine in this way may allow the electric machine to emulate wheel creep torque that is generated via an engine.

Abstract: Methods and systems are provided for providing off-road capabilities in electric vehicles with a single gear reduction. In one example, when a 4×4 mode is selected in an electric vehicle, a relationship between motor torque and accelerator pedal position is changed so as to increase the vehicle creep wheel torque. A degree of increase of the creep wheel torque is adjusted as a function of the terrain on which the vehicle is off-roading.

Abstract: Systems and methods changing between driveline operating modes of a hybrid vehicle are described. In one example, electrical output to electric power consumers is maintained during closing of a driveline disconnect clutch. Further, engine speed is controlled via a first electric machine to a speed of a second electric machine to provide smooth closing of a driveline disconnect clutch.

Abstract: Methods and systems are provided for controlling a distribution between engine and motor torques for a hybrid electric vehicle operating in a creep mode of operation in response to an engine start request. In one example, responsive to a request to start an engine while a vehicle is being propelled at a predetermined wheel creep torque via an electric motor positioned downstream of a transmission and a torque converter, coordinating an electric motor torque and an engine torque in one of a first mode, second mode, or a third mode depending on whether the electric motor can continue to provide the predetermined wheel creep torque. In this way, engine idle speed may be minimized depending on vehicle operating conditions, which may improve fuel economy.

Abstract: Methods and systems are provided for controlling engine operation in response to a request to shift a transmission gear. In one example, a method may include maintaining operating conditions of an engine and redirecting electric power generated via the engine from a traction motor to a battery in response to a request to shift a transmission while the driveline is operating in a series mode. In this way engine efficiency may be improved and a time frame for shifting a transmission gear may be reduced responsive to a gear shift request while the powertrain is operating in series mode.

Abstract: Systems and methods for operating a vehicle that includes an engine and an electric machine are described. In one example, electric machine torque is adjusted according to a wheel torque in a wheel torque creep mode where an engine provides torque to vehicle wheels. Operating the electric machine in this way may allow the electric machine to emulate wheel creep torque that is generated via an engine.

Abstract: A vehicle includes an actuator, a drivetrain configured to receive mechanical power from the actuator, an accelerator pedal position sensor configured to output a driver-demanded torque, and a controller in electric communication with the sensor and the actuator. The controller is programmed to receive the driver-demanded torque and output a shaped torque command to mitigate driveline disturbances caused by backlash and shaft compliance.

Abstract: A vehicle includes a traction battery and a powertrain. The powertrain including at least one traction motor electrically connected to the battery such that the traction motor discharges the battery when producing positive torque to propel the vehicle and recharges the battery when producing negative torque to slow the vehicle. A vehicle controller is programmed to execute coast (lift-pedal) controls that reduce the charge rate of the battery based on a ratio of energy capacity of the battery to kinetic energy of the vehicle.

Abstract: Methods and systems are provided for providing off-road capabilities in electric vehicles with a single gear reduction. In one example, when a 4×4 mode is selected in an electric vehicle, a relationship between motor torque and accelerator pedal position is changed so as to increase the vehicle creep wheel torque. A degree of increase of the creep wheel torque is adjusted as a function of the terrain on which the vehicle is off-roading.

Abstract: Systems and methods for operating a vehicle that includes an engine and an integrated starter/generator are described. In one example, torque generated via the engine is based on a requested driveline torque and a torque of an electric machine when degradation of an engine sensor is present. The torque generated via the engine may be adjusted responsive to a requested engine torque and a feedback engine torque that is based on output of an engine airflow sensor.