A powertrain system including an electric machine rotatably coupled to a crankshaft of an internal combustion engine via a belt is described, wherein the electric machine is disposed to generate torque. A method for controlling the electric machine includes monitoring rotational position of the electric machine, and periodically executing a speed observer to determine a rotational speed of the electric machine based upon the monitored rotational position of the electric machine. An acceleration observer is periodically executed to determine an acceleration rate, wherein the acceleration rate is determined based upon a time-based change in the rotational speed of the electric machine. A virtual inertia term is determined based upon the acceleration rate, and a torque compensation term is determined based upon the virtual inertia term and the acceleration rate. The electric machine is controlled to generate torque based upon the torque compensation term.

A method for vibration dampening of a drive train is disclosed. The method includes determining torsional parameters of the drive train via a state controller based on reconstructed torsional parameters of the at least one flywheel mass detected by at least one observer, determining the reconstructed torsional parameters based on disturbances in both (i) a load torque (M.sub.last) applied at an output of a torque transmission device and (ii) an induced torque (M.sub.ind) transmitted via the torque transmission device, determining a compensation torque via the state controller based on the reconstructed torsional parameters, and controlling an electric machine via the state controller based on the compensation torque to compensate torsional vibrations.

A drive force control system for hybrid vehicles configured to reduce a change in a drive force simultaneous execution of a starting operation of an engine and a shifting operation of a transmission. The drive force control is applied to a hybrid vehicle comprising: an engine connected to front wheels; a first motor connected to rear wheels; and a transmission that changes a speed ratio between the first motor and the rear wheels. A controller restricts execution of any one of an engine staring operation and a shifting operation of the transmission during execution of other one of the engine staring operation and shifting operation of the transmission.

A system and method for modifying the engine pull-up (EPU) logic within a hybrid vehicle based on max motor torque that accounts for the drop or change in available motor torque due to the opening/slipping of a torque converter bypass clutch during engine starts is disclosed. An engine pull-up threshold is determined from max available motor torque at a virtual impeller speed, where the virtual impeller speed is the impeller speed that would result if the torque converter bypass clutch was open/slipping and transferring the same amount of torque.

Systems and methods for operating a hybrid vehicle driveline that includes an engine and a motor are presented. In one example, the systems and methods include one or more speed control modes where torque output of a motor is adjusted responsive to different control parameters in the different control modes.

A method and a system for improving operation of a hybrid vehicle are presented. In one example, torque converter impeller torque from beginning to end of transmission shifting is adjusted in response to variable driveline inertia. The approach may improve transmission shifting and reduce driveline torque disturbances.

The present disclosure provides a shift control method for a hybrid vehicle with a DCT that includes: a shifting state-determining step in which a controller determines whether an inertia phase of power-off down-shift is entered; a motor torque-adjusting step that request to reduce regenerative braking torque of a motor as much as a predetermined requested reduction amount, when the controller determines that the inertia phase has been entered in the shifting state-determining step; and a clutch torque-reducing step that ends the motor torque-adjusting step and reduces torque of an engagement clutch, when the requested reduction amount of the regenerative braking torque of the motor is less than zero while the controller performs the motor torque-adjusting step.

A MGECU in a control device mounted on a vehicle has a feedback control section, a correction torque calculation section, an instruction torque calculation section. The feedback control section calculates a torque to be used for performing a feedback control of an actual rotation speed to follow a target rotation speed. The correction torque calculation section calculates a correction torque based on a change rate of the target rotation speed and inertia of a rotary body which includes the motor generator. When the target rotation speed is changed to decrease a difference between the target rotation speed and the actual rotation speed, the correction torque calculation section reduces the correction torque. The instruction torque calculation section adds the torque calculated by the feedback control section and the correction torque calculated by the correction torque calculation section in order to obtain the instruction torque to be used for the motor generator.

An FF hybrid vehicle control device having an HEV mode and an EV mode as drive modes is provided with a CVT control unit (84) for determining primary pulley pressure (Ppri) and secondary pulley pressure (Psec) with which a belt (6c) of a belt-type continuously variable transmission (6) will be clamped on the basis of a torque component inputted to the belt-type continuously variable transmission (6) during brake deceleration, and the corrected amount of brake torque which is an inertia torque correction component. The CVT control unit (84) reduces the corrected amount of brake torque during brake deceleration when EV mode is selected to be less than the corrected amount of brake torque during brake deceleration when HEV mode is selected.

The present disclosure provides a shift control method for a hybrid vehicle with a DCT that includes: a shifting state-determining step in which a controller determines whether an inertia phase of power-off down-shift is entered; a motor torque-adjusting step that request to reduce regenerative braking torque of a motor as much as a predetermined requested reduction amount, when the controller determines that the inertia phase has been entered in the shifting state-determining step; and a clutch torque-reducing step that ends the motor torque-adjusting step and reduces torque of an engagement clutch, when the requested reduction amount of the regenerative braking torque of the motor is less than zero while the controller performs the motor torque-adjusting step.