A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a dynamic firing level modulation manner. A smoothing torque is determined by adaptive control that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.

Disclosed are a method of and an apparatus for controlling a vibration of a hybrid electric vehicle. An apparatus for controlling a vibration of a hybrid electric vehicle may include: an engine position detector detecting a position of an engine; an air amount detector detecting an air amount flowing into the engine; an accelerator pedal position detector detecting a position of an accelerator pedal; a vehicle speed detector detecting a speed of the hybrid electric vehicle; and a controller. The controller controls operation of a motor based on the position of the engine, the air amount, the position of the accelerator pedal, and the speed of the hybrid electric vehicle.

An internal combustion engine assembly for a motor vehicle is provided. The engine assembly comprising: an engine; an electric motor; and a balance shaft comprising an eccentric mass, wherein the electric motor is configured to selectively rotate the balance shaft in order to balance a vibration characteristic of the engine. A method of operating the engine assembly is also provided.

A misfire detection system and method for a vehicle utilize a controller to obtain a crankshaft speed signal indicative of a rotational speed of an engine crankshaft connected to a device that mitigates vibrational disturbances at the crankshaft caused by misfires of the engine, detect that a first firing event of the engine is a first misfire based on the crankshaft speed signal, monitor a vibrational response of the crankshaft, detect that a consecutive second firing event of the engine is a second misfire based on a first modified crankshaft speed signal and the first set of thresholds, and in response to detecting the second misfire, reset the monitoring of the vibrational response of the crankshaft including modifying the amplitude of the crankshaft speed signal to obtain a second modified crankshaft speed signal and comparing the second modified crankshaft speed signal to a set of thresholds.

A method for mitigating clunk in a driveline of a vehicle system during a declutch event includes determining a current torque request of a prime mover based on an accelerator pedal position of an accelerator pedal of the vehicle system. The method includes determining a clutch pedal position and determining, via a controller, a clutch pedal speed based on a change of the clutch pedal position over time. The method further includes modifying, via the controller, the current torque request to obtain a modified torque request based on the clutch pedal position and the clutch pedal speed such that a stored potential energy in the driveline is minimized by a time that the clutch pedal of the vehicle system is disengaged during the declutch event.

A control apparatus for a hybrid vehicle is configured to control the hybrid vehicle. The control apparatus is provided with: an arithmetic operator configured to arithmetically operate a pulsation compensating torque for compensating a pulsation component; an arithmetic operation controller configured to control the arithmetic operator (i) to arithmetically operate the pulsation compensating torque in a first cycle in a period that does not include a vertex portion in which the pulsation compensating torque is locally maximal or locally minimal and (ii) to arithmetically operate the pulsation compensating torque in a second cycle, a length of which is shorter than that of the first cycle, in a period that includes the vertex portion; and a torque controller configured to control the electric motor to output a torque including the pulsation compensating torque arithmetically operated by the arithmetic operator.

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under a condition that an engine speed is constant, to set the countertorque such that, as the average torque output by the engine becomes larger, the absolute value of the countertorque becomes larger.

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under a condition that an engine speed is constant, to set the countertorque such that, as the average torque output by an engine becomes larger, the absolute value of the countertorque becomes smaller.

A method for mitigating clunk in a driveline of a vehicle system during a declutch event includes determining a current torque request of a prime mover based on an accelerator pedal position of an accelerator pedal of the vehicle system. The method includes determining a clutch pedal position and determining, via a controller, a clutch pedal speed based on a change of the clutch pedal position over time. The method further includes modifying, via the controller, the current torque request to obtain a modified torque request based on the clutch pedal position and the clutch pedal speed such that a stored potential energy in the driveline is minimized by a time that the clutch pedal of the vehicle system is disengaged during the declutch event.

A method of controlling a hybrid vehicle includes commanding a first electric machine to provide a compensating torque. The compensating torque is based on a calculated cylinder pressure. The calculated cylinder pressure is calculated using a dynamic model. The model has an initializing input of engine crank position and real-time inputs of measured speed of the first electric machine and measured speed of the second electric machine.