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 control methods can provide for determining a TrnAin torque request from desired vehicle acceleration in a vehicle that utilizes a WTC architecture to allow for smooth transition between different transmission states, such as torque converter bypass clutch states and shifts between transmission gear ratios. The methods provide consistent and smooth vehicle acceleration profile during transmission state transitions. The methods also provide the ability to track the desired vehicle acceleration consistently from virtual driver demand sources, such as adaptive cruise control, autonomous vehicle, or remote parking, without allocating any additional resource to account for transmission state transitions. The proposed methods are applicable to any TC-based automatic transmission drivetrain, such as conventional powertrain, MHT, P4 HEV, or even BEV powertrains where the motor is located on the impeller side of a torque converter.

Abstract: Methods and system for operating a vehicle cooling system are described. In one example, the vehicle cooling system cools a heat generating device via a fan and pump. A speed of the fan is commanded by a feedback controller with possible neural network predictive control to track a variable temperature reference that is based on thermal load estimation. A disturbance observer may be applied to observe thermal load and an observer-based observer may be used to generate the temperature reference so that the power consumption of a fan is minimized.

Abstract: Methods and systems are provided for coordinating engine and motor torque in a hybrid vehicle system. The systems and methods use an engine torque command to obtain a motor torque command, and adjust the engine torque command based on an estimate of a time delay between commanded and actual motor torque prior to the engine command being sent to an engine controller. In this way, crankshaft torque accuracy may be improved.

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 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: 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: 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: Systems and methods for operating an engine that may selectively enter and exit a fuel cut-off mode are described. In one example, the method holds the engine in the fuel cut-off mode even though a propulsive effort pedal is applied. An electric machine may provide torque to a vehicle driveline while the engine is in the fuel cut-off mode.

Abstract: Methods and systems are provided for controlling yaw of a vehicle while maintaining vehicle speed. In one example, equal and opposite vectoring torques are applied to first and second wheels along with a propulsion torque so that a vehicle yaw moment may be induced without accelerating or decelerating the vehicle.

Abstract: Systems and methods for operating a vehicle that includes an engine and an electric machine are described. In one example, torque requests are aligned in time to compensate for a delay that may be caused by broadcasting one or more torque commands over a controller area network or another type of communication link. The torque requests may be aligned via delaying an engine torque request and predicting an electric machine torque.

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: One axle of a hybrid vehicle is powered by an electric motor while a second axle of the vehicle is powered by a powertrain that includes an internal combustion engine. The electrically driven axle can be controlled in a speed control mode or in a torque control mode based on a driver demanded torque. The speed control mode is used when slip is detected at the electrically driven axle. The torque control mode is used when the electrically driven axle has traction. During a transition between these modes, the rate of change of torque is controlled to a predetermined level to mitigate noise, vibration, and harshness.

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.

Abstract: Methods and systems are provided for improving engine restart operations occurring during a transmission shift in a hybrid vehicle. Engine speed is controller during cranking and run-up to approach a transmission input shaft speed that is based on the future gear of the transmission shift. Engine speed is controlled via adjustments to spark, throttle, and/or fuel, to expedite engine speed reaching the synchronous speed.

Abstract: A hybrid vehicle includes an electric machine, an engine selectively coupled to the electric machine by a disconnect clutch, and a controller. The controller is programmed to, in response to a change in the driver-demanded torque necessitating starting of the engine: determine a state of driving (SOD) based on the change in driver-demanded torque, wherein the SOD is indicative of a desired responsiveness of the vehicle, and the desired responsiveness increases as SOD increases; command a speed target to the engine equal to a predicted motor speed associated with the driver-demanded torque plus an offset that is based on the SOD; and command a capacity to the disconnect clutch at a rate and a magnitude based on the SOD.

Abstract: A system and method is disclosed for engine starting and transmission shifting where a controller may be operable to decrease a torque of a motor and operate a starter-generator (ISG) to start an engine responsive to a command to shift the transmission and start the engine. The controller may disengage a second clutch and subsequently shift the transmission to a target gear ratio speed responsive to the torque of the motor achieving zero. The controller may increase respective torques of the motor, ISG, and engine to drive a speed of the motor, ISG, and engine toward a target speed defined by the target gear speed responsive to completion of the shift. The controller may engage the second clutch responsive to the speed of the motor achieving the target speed and engage a disconnect clutch responsive to the respective speeds of the ISG and engine achieving the target speed.

Abstract: Methods and systems are provided for adjusting driver demand wheel torque of a vehicle. The driver demand wheel torque may be adjusted as a function of a minimum wheel torque. The minimum wheel torque may be determined according to a plurality of torques that may be evaluated in three different phases.

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: Systems and methods for operating a driveline of a hybrid vehicle are described. In one example, a torque of an engine is adjusted in response to an error between an actual electric machine torque and a minimum electric machine torque plus an offset torque. The reduction of engine torque may be performed when a driveline is operating in a speed control mode.