Abstract: When a shift lever is in a parking position, a rotation restriction index Jm2 is set based on a drive state of an engine or a first motor (S130, S160, S240, and S290). A current value based on the rotation restriction index Jm2 is set to a current command of the d axis in an electric angle when motoring of the engine in a stop state is started and a second motor is controlled such that the magnetic field direction of a stator of the second motor is fixed. This method can appropriately prevent a power shaft from rotating.

Abstract: In response to a starting instruction of an engine at a gearshift position of a gearshift lever set to a parking position, a motor is controlled to form a fixed magnetic field on a stator of the motor at the level that is capable of preventing rotation of a rotating shaft against a torque applied to the rotating shaft within magnitude less than or equal to magnitude of a rotation restriction control torque based on a temperature of the motor and a discharge power from the battery, a motor is controlled to perform the motoring of the engine while the motor outputs a torque that makes a torque applied to the rotating shaft less than or equal to magnitude of the rotation restriction control torque, and the engine is controlled to be started with the motoring.

Abstract: A torque command (Tht) used in the calculation of a voltage command (Vht) of a voltage-up converter is generated by adding an upper limit value value (Tc_max) of damping control that can be set by a motor drive device with a target drive torque (Tbt). Accordingly, the torque command (Tht) exhibits a waveform absent of variation, differing from a torque command (Tcmd) that is generated by adding damping torque generated based on revolution count variation component with the target drive torque (Tbt). Therefore, the voltage command (Vht) calculated based on the torque command (Tht) exhibits a waveform absent of variation. Accordingly, increase in current passing through the voltage-up converter caused by variation in the voltage command (Vht) can be suppressed. As a result, power loss at the voltage-up converter is reduced and operation of the motor at high efficiency can be realized. Further, the voltage-up converter can be protected from element fracture.

Abstract: At a time of stopping operation of an engine, after elapse of a preset time period since start of self-sustaining operation of the engine at a stop rotation speed Nstop, the drive control sets a torque command Tm1* of a motor MG1 to a rotation speed-decreasing, vibration-suppressing torque and starts decreasing a rotation speed Ne of the engine (steps S100, S140, S150, S170, and S180). The rotation speed-decreasing, vibration-suppressing torque is set to smoothly decrease the rotation speed of the engine and suppress the potential vibration caused by the decreased rotation of the engine. A correction torque Tmod is set based on a crank angle CA and an engine water temperature Tw at the rotation speed Ne of the engine decreasing to a preset reference speed Nref (step S200). The torque command Tm1* of the motor MG1 is then set by adding the set correction torque Tmod to the rotation speed-decreasing, vibration-suppressing torque (step S210).

Abstract: In a power train in which a differential mechanism is coupled with a transmission mechanism, a transmission member is free with no engagement in a second shift portion when a P position or an N position is selected, and a ring gear thereby becomes free in a power split device. During an idle operation with such a shift position, a behavior of an engine rotation speed is retained in a stable manner in the power split device which functions as the differential mechanism through a power supply control (lock control) such that a rotor of a second MG coupled with the ring gear is locked by an electromagnetic force, and then, a learning control of an idle speed control is appropriately implemented.

Abstract: In response to a change of a gearshift position from a parking position to a driving position, the control system of the invention connects a power shaft with a driveshaft linked to drive wheels (steps S310 and S380), while performing rotation restriction control to form a fixed magnetic field on a stator of a second motor and thereby prohibit rotation of a rotor in the second motor (step S300). This arrangement desirably restrains rotation of the power shaft and accordingly prevents the occurrence of a shock in the course of connection of the power shaft with an axle.

Abstract: When a shift lever is in a parking position, a rotation restriction index Jm2 is set based on a drive state of an engine or a first motor (S130, S160, S240, and S290). A current value based on the rotation restriction index Jm2 is set to a current command of the d axis in an electric angle when motoring of the engine in a stop state is started and a second motor is controlled such that the magnetic field direction of a stator of the second motor is fixed. This method can appropriately prevent a power shaft from rotating.

Abstract: In stopping an internal combustion engine, an engine stop is controlled such that, among a plurality of cylinders of the internal combustion engine, a cylinder arranged at a position close to a transmission halts in a compression stroke. More specifically, in stopping an internal combustion engine, at a point when the rotation speed of the internal combustion engine becomes less than a prescribed value (ST3), the remaining rotation angle required for a cylinder #4 close to a transmission to halt in a compression stroke is calculated (ST5). Based on the calculated value of the remaining rotation angle, a crankshaft of the internal combustion engine is forcibly driven by controlling the driving of an electric motor (for example, motor generator) (ST6), so that cylinder #4 closest to the transmission is stopped in a compression stroke.