A control apparatus of a hybrid vehicle has an abnormal sound generation condition determination unit that determines whether or not an abnormal sound generation condition of a gear train is satisfied, and a pressing processor that applies a pressing torque from a first rotary electric machine to the gear train when a retention time, which is a period in which the abnormal sound generation condition continues to be satisfied, exceeds a predetermined value, and that does not apply the pressing torque when the abnormal sound generation condition is not satisfied and when the retention time is within the predetermined value. A pressing torque setting unit sets a pressing torque to be applied by the first rotary electric machine to a direction to suppress an engine cam torque which may rotate an engine output shaft.

Methods and systems are provided for reducing torque pulsations during hybrid engine shutdown and restarts. A valve actuating mechanism may be actuated to operate an engine with a selected valve lift profile during engine restart and shutdown events that is distinct from the valve lift profile applied during cylinder combustion. The selected valve lift profile reduces cylinder pressure during engine shutdown and restarts.

An apparatus for active vibration control of a hybrid electric vehicle including an engine and a motor is disclosed. The apparatus includes: a position sensor to detect position information of the engine or the motor; and a controller to select a reference angle signal based on a signal from the position sensor. The controller performs fast Fourier transform (FFT) analysis by generating a reference angle, extracts a vibration component of each frequency through the FFT analysis, generates a reference signal by performing inverse FFT, and performs active vibration control of each frequency by reflecting a basic amplitude ratio, an adjustable rate according to an engine load, and an engine torque to the reference signal.

A controller includes control means for controlling an electric motor such that a pulsation compensation torque corresponding to a pulsation component of a torque of an internal combustion engine, which appears in a drive shaft, is supplied to the drive shaft as a damping torque for suppressing vibrations of the hybrid vehicle, and determination means for determining whether a torque of the electric motor, excluding the pulsation compensation torque, is smaller than a predetermined value. When it is determined that the torque excluding the pulsation compensation torque is smaller than the predetermined value, the control means controls the electric motor such that the sum of the pulsation compensation torque and a pressing torque corresponding to the predetermined value is supplied to the drive shaft as the damping torque.

A method for active vibration control of a hybrid electric vehicle may include: selecting a reference angle signal based on position information of a motor or an engine; generating a reference angle based on information of the reference angle signal; setting up a period of fast Fourier transform (FFT) and analyzing the FFT signal; setting up a reference spectrum according to an engine speed and an engine load; extracting a vibration component from each frequency based on information of the reference spectrum; selecting and adding a removal object frequency from the vibration of each frequency and performing inverse FFT; determining a basic amplitude ratio according to the engine speed and the engine load and an adjustable rate according to the engine load; and performing active vibration control of each frequency based on the information of the basic amplitude ratio, the adjustable rate, and the engine torque.

A four-wheel drive vehicle is provided, including an engine with an operating mode that is switchable between all-cylinder and reduced-cylinder operating modes, a torque transmission assembly for transmitting an output torque of an engine to main drive wheels and auxiliary drive wheels, a torque ratio adjusting device included in the torque transmission assembly and configured to adjust a ratio of the output torque distributed to the auxiliary drive wheels, and controller that executes a noise suppression module for increasing the torque ratio provided to the auxiliary drive wheels by the torque ratio adjusting device so as to suppress noise generation at the torque transmission assembly, in the all-cylinder and reduced-cylinder operating modes. The noise suppression device changes the torque ratio provided to the auxiliary drive wheels according to engine operating ranges where the torque transmission assembly is in a noise generating state in the all-cylinder and reduced-cylinder operating modes, respectively.

Methods and systems are provided for improving surge control. When surge conditions are anticipated, motor torque usage is increased to discharge a battery to a lower state of charge. When surge conditions actually occur, engine torque output is limited to a higher level than the engine output required to meet the reduced torque demand, while the excess wheel torque is offset by charging the battery to a higher state of charge.

An apparatus for reducing vibrations of a two-cylinder engine for a hybrid electric vehicle includes a reference signal generator for generating a first reference signal and a first reference phase, a speed calculator for calculating a speed of the motor based on the position of the motor, a vibration extractor for extracting a first vibration signal based on the speed of the motor, a variable filter, a filter coefficient updater, a phase calculator, a phase shift compensator, a synchronization signal generator for generating a first synchronization signal synchronized with the first vibration signal based on a first reference phase transferred from the reference signal generator, the second phase difference transferred from the phase calculator and the first compensation value transferred from the phase shift compensator, an inverse phase signal generator, and a torque generator for generating a final command torque based on the first inverse phase signal.

A powertrain assembly includes a transmission, an engine, first and second motor/generators and a controller. The controller includes a processor and memory on which is recorded instructions for executing a method for controlling engine pulse torque cancellation commands. The controller is programmed to determine an engine pulse torque (T.sub.P). The controller is programmed to calculate a first motor torque pulse command (T.sub.A) for the first motor/generator as a product of a first gear factor (G.sub.1), the engine pulse torque (T.sub.P) and a first ratio (I.sub.A/I.sub.E) of a predetermined first moment of inertia (I.sub.A) for the first motor/generator and a predetermined engine moment of inertia (I.sub.E). Similarly, the controller is programmed to calculate a second motor torque pulse command (T.sub.B) for the second motor/generator. The controller is programmed to control the first and second motor/generators in response to the first and second motor torque pulse commands, respectively.

The present disclosure provides a method for controlling a power take-off assembly. The method includes providing a drive unit, a transmission having an output, a speed sensor, a controller including a memory unit and a processor, and the power take-off assembly including a clutch and a solenoid. The method also includes storing a first threshold in the memory unit, determining a current input speed of the drive unit with the speed sensor, and comparing the current input speed to the first threshold. The method further includes controlling an amount of hydraulic pressure supplied to the clutch and engaging the clutch.