A control device of a powertrain system executes a control input determination processing and a system control processing. The control input determination processing includes a co-state variable determination processing to update a co-state variable p of an optimization problem for each time step and a control input calculation processing. The co-state variable determination processing includes an initial value determination processing that determines, as an initial value of the co-state variable p, the sum of a base value of the initial value and an external charge/discharge correction value. The base value is a final value or an average value of the co-state variable p during the last control time period. The external charge/discharge correction value is determined based on an external charge/discharge amount obtained by subtracting a SOC at the end of the last control time period from the SOC at the start of the current control time period.

Since a maximum rotation speed of a second rotary machine is set to a lower value when a supercharging pressure is high than when the supercharging pressure is low, an engine torque decreases with an rotation speed of the second rotary machine which is relatively low and the rotation speed is less likely to fall into a high-rotation state. When the supercharging pressure is relatively low and the rotation speed is less likely to reach an upper-limit rotation speed of the second rotary machine, the maximum rotation speed is set to a relatively high value. Accordingly, the engine torque does not decrease to the rotation speed which is relatively high and power performance can be easily secured. As a result, it is possible to prevent a decrease in power performance due to the decrease in the engine torque and to prevent the rotation speed from falling into a high-rotation state.

A hybrid vehicle includes: an engine; a battery; a power converter; a relay; a first controller; and a second controller. The second controller is configured to control the engine and the power converter according to allowable charging power and allowable discharging power received from the first controller. The second controller has, as control modes, a normal mode in which the relay is closed and the battery and the power converter are electrically connected and a batteryless drive mode in which the relay is opened to cause the hybrid vehicle to move with the battery electrically disconnected from the power converter. The second controller is configured to select the batteryless drive mode when at least one of the magnitude of the allowable charging power and the magnitude of the allowable discharging power become smaller than a first predetermined value.

A drive system for a vehicle includes a first planetary device, a second planetary device directly coupled to the first planetary device, a first electromagnetic device at least selectively coupled to the first planetary device and including a first shaft, a second electromagnetic device directly coupled to the second planetary device and including a second shaft, and an output shaft coupled to the first planetary device. The first shaft and the second shaft are radially aligned with the first planetary device and the second planetary device. The output shaft is radially aligned with the first planetary device and the second planetary device.

A drive system for a vehicle includes a first planetary device, a second planetary device directly coupled to the first planetary device, a first electromagnetic device at least selectively coupled to the first planetary device and including a first shaft, a second electromagnetic device directly coupled to the second planetary device and including a second shaft, and an output shaft coupled to the first planetary device. The first shaft and the second shaft are radially aligned with the first planetary device and the second planetary device. The output shaft is radially aligned with the first planetary device and the second planetary device.

A vehicle driving apparatus includes: a rotating machine; a cover covering the rotating machine and including a thick portion having a predetermined thickness in a direction of a rotation axis of the rotating machine; an oil pump attached to the cover; and a relief valve provided in the cover, and configured to discharge an oil supplied from the oil pump. The relief valve includes a cylinder room that is provided in the thick portion. The thick portion is provided with at least one cutout extending from an inner wall of the cylinder room in a direction substantially perpendicular to the rotation axis. The cover is provided with at least one rib each of which is disposed in a position opposed to a corresponding one of the at least one cutout and extends in the direction of the rotation axis.

A torque reducing process reduces torque of a multiphase rotating electric machine when a magnitude of current in a particular phase of the rotating electric machine remains greater than or equal to a given value. A deactivating process deactivates combustion control in a deactivated cylinder and continues combustion control in the remaining cylinders. A fluctuation torque applying process cyclically fluctuates the torque of the rotating electric machine in a cycle that is an integral multiple of a compression top dead center occurrence cycle when the deactivating process is being executed. A prohibiting process prohibits execution of the deactivating process in a predetermined situation where a rotation speed of a rotary shaft of the rotating electric machine is less than or equal to a given speed.

A four-wheel drive system with boosting operation includes: a battery; a voltage boosting device; a front wheel drive unit connected parallel to the battery via the voltage boosting device and including a first motor generator and a first inverter; and a rear wheel drive unit connected parallel to the battery bypassing the voltage boosting device and including a second motor generator and a second inverter. An output power of front wheel drive unit is higher than an output power of rear wheel drive unit, and the output power of rear wheel drive unit is higher than a boosted output power of voltage boosting device. The control method of four-wheel drive system with boosting operation includes controlling the front and rear wheel drive units such that an output power flowing through the voltage boosting device does not exceed a rated boosted output power of voltage boosting device.

When evacuation travel is performed using only a drive power from one drive power source of an engine and a rotary machine, a drive power distribution device is prohibited from switching to a four-wheel-drive state and thus evacuation travel is performed in a two-wheel-drive state in which a loss in a power transmission device is relatively small. Accordingly, in a four-wheel-drive vehicle, it is possible to increase an evacuation-travelable distance when evacuation travel is performed using only the drive power from one drive power source of the engine and the rotary machine.

Methods and systems are provided for improving torque control of a vehicle that includes simulated shifting of a step gear ratio transmission. In one example, a propulsive effort request is gradually incrementally increased or decreased to provide a smooth torque transition, thereby providing a smoother vehicle speed change and improve vehicle drivability.