A locomotive propulsion system includes an engine assisting apparatus and an engine control unit that monitors an output parameter of a locomotive engine. The control unit determines whether the engine output decreases sufficiently low to at least partially de-fuel the engine and to activate an assisting apparatus. This assisting apparatus rotates a shaft of the engine with or without the engine also rotating the shaft. Rotation of the shaft by the assisting apparatus can be used to power traction motors or other loads of the locomotive while reducing fuel consumption and/or emission generation by the engine.

The present invention relates to an engine torque control method of a mild hybrid electric vehicle including an engine as a power source, the mild hybrid electric vehicle further includes a mild hybrid starter and generator (MHSG) which starts the engine or operates as a generator by an engine torque and a controller which controls the change of a fuel injection mode among a MPI engine mode using a low pressure injector which injects the fuel to an intake port of the engine, a GDI engine mode using a high pressure injector which injects a fuel to a combustion chamber of the engine, and a hybrid MPI and GDI engine mode using both the low pressure injector and the high pressure injector, and the engine torque control method includes: determining whether a fuel injection mode is a MPI engine mode, by the controller, measuring a maintaining period when the MPI engine mode is maintained by a timer when the fuel injection mode is the MPI engine mode, determining whether the fuel injection mode is changed from the MPI engine mode to the GDI engine mode or the hybrid MPI and GDI engine mode, by the controller; and, driving the MHSG by the controller to assist an engine torque when the fuel injection mode is changed from the MPI engine mode to the GDI engine mode or the hybrid MPI and GDI engine mode.

Methods and systems are provided for controlling clutch capacity in a hybrid electric vehicle. In one example, a method includes adjusting values of a transfer function of a clutch of a dual clutch transmission in response to an operating condition of an engine and/or operating condition of an integrated starter/generator coupled to the engine while a vehicle is propelled via an electric machine coupled to the dual clutch transmission, and maintaining a driver demand wheel torque at vehicle wheels via adjusting torque of the electric machine in response to the operating condition of the engine and/or operating condition of the integrated starter generator. In this way the method may apply pressure to one of the clutches where engine speed is independently controlled to maintain positive or negative slip, thus enabling adaptation of positive and negative clutch transfer functions, which may improve driveline operation and shift quality.

A method for controlling a mild hybrid vehicle is disclosed. The method includes: controlling a multi-point injection (MPI) fuel system for supplying fuel to an engine for a low revolutions-per-minute (RPM) operation; subsequently, causing a gasoline direct injection (GDI) fuel system for a high RPM operation; switching to the multi-point injection fuel system when it is determined that the gasoline direct injection fuel system fails. The method further comprises calculating a torque deficiency due to the switching from the GDI fuel system to the MPI fuel system and controlling a starter-generator to generate an assist torque to compensate the torque deficiency.

Methods and systems are provided for adjusting clutch pressures and electric machine torques as a function of a stability metric threshold(s) in order to balance performance and charging of an onboard energy storage device. In one example, a method includes during an upshift of a transmission from a first gear to a second gear, adjusting a clutch pressure of the transmission to adjust slippage of a clutch in response to a vehicle stability control parameter exceeding a threshold. In this way, torque delivered to a transmission output shaft may be reduced, which may increase vehicle stability.

A vehicle control apparatus includes an engine, a refrigerant compressor, a lock up clutch, a throttle valve, and first, second, and third deceleration controllers. The second deceleration controller controls the lock up clutch to a slip state and controls the throttle valve openwise on the condition that the refrigerant compressor is in the stopped state on decelerated travel of a vehicle in a second speed region in which a vehicle speed is lower than a first vehicle speed and higher than a second vehicle speed lower than the first vehicle speed. The second deceleration controller controls the lock up clutch to a disengaged state and controls the throttle valve closewise on the condition that the refrigerant compressor is in the operative state on the decelerated travel of the vehicle in the second speed region.

Systems and methods for operating a driveline of a hybrid vehicle are disclosed. In one example, an engine may enter or stay in one of two cylinder deactivation modes or enter or stay in a combustion mode in response to a request to downshift a transmission while a vehicle in which the engine resides is coasting.

A system for controlling a compressor may include an engine controller that controls a fuel injection amount corresponding to an engine load and an opening amount of a throttle by reflecting a required torque required for an air conditioner (A/C), an operation information detector for detecting operation information according to driving state of the vehicle, a compressor that generates pressure during operation of the A/C, an air conditioner relay which is turned on when the air conditioner operates and is turned off when the A/C is stopped, and a controller which determines an engine negative pressure of an intake manifold, and when the cooling water temperature is lower than the predetermined temperature and the intake manifold pressure is lower than the first threshold value, a cold-start intake manifold negative pressure insufficient event is generated to reduce the A/C duty in accordance with the entry into a negative pressure recovery mode.

The present invention relates to a method for determining engine operation parameter values during and/or after a gear shift operation prior to performing said gear shift operation. The method comprises the steps of, prior to the gear shift operation: determining initial conditions comprising torque demand and engine speed and certain other engine operation parameter values; providing said initial conditions to an engine operation simulation model; providing a torque development course as well as an engine speed development course during the intended gear shift operation to said engine operation simulation model; and determining desired engine operation parameter values by means of said engine operation simulation model based upon the information thus provided to said engine operation simulation model.

A range extender for a vehicle, comprises an electric machine; an engine; and a controller, wherein the controller is configured to control fuelling of the engine, and is configured to control the electric machine to charge a battery of the vehicle using power from the engine and at other times to control the electric machine to drive the engine using power from the battery, wherein the controller is configured to increase the engine speed by controlling the electric machine to drive the engine using power from the battery whilst substantially not fuelling the engine.