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.

There are provided a controller and a control method for a hybrid vehicle including an engine with a supercharger serving as a drive power source for travel, a rotary machine serving as a drive power source for travel, and a power storage device configured to transmit and receive electric power to and from the rotary machine. The controller determines whether an operation of the supercharger is limited, compensates for a torque shortage of the engine due to limitation of the operation of the supercharger by a torque of the rotary machine when it is determined that the operation of the supercharger is limited, and curbs a decrease in an amount of electric power stored in the power storage device more when it is determined that the operation of the supercharger is limited than when it is determined that the operation of the supercharger is not limited.

It is determined whether chargeable and dischargeable electric power of a battery which is a power storage device are limited. When it is determined that the chargeable and dischargeable electric power of the battery is limited, an electric power balance target value of the battery during gear shifting control in a stepped gear shifting unit which is a mechanical gear shifting mechanism is calculated. A smaller value is calculated as a change rate limit value when the chargeable and dischargeable electric power is small than when the chargeable and dischargeable electric power is great, and the calculated change rate limit value is used to perform gear shifting control in the stepped gear shifting unit.

When a speed difference between a maximum rotation speed and an engine rotation speed, that is, an actual rotation speed difference, is equal to or less than a margin rotation speed difference, an engine operating point is changed such that the actual rotation speed difference becomes greater than the margin rotation speed difference. Accordingly, the speed difference between the maximum rotation speed and the engine rotation speed is prevented from becoming equal to or less than the margin rotation speed difference. As a result, since a relatively sufficient margin is secured in the difference between the maximum rotation speed and the engine rotation speed, it is possible to prevent the engine rotation speed from falling into a high-rotation state in which the engine rotation speed exceeds the maximum rotation speed.

An MG1 torque at a time of decreasing an engine speed of an engine is made larger when a turbocharging pressure by a turbocharger is higher than when the turbocharging pressure is lower. In this way, even if the losses of pumps of the engine differ due to the remaining turbocharging pressure during a transition of stopping the engine in turbocharging, it is possible to appropriately reduce the engine speed. Therefore, when the engine is being brought to a stop, it is possible to appropriately suppress vibration generated in the vehicle.

A control system for a hybrid vehicle configured to reduce electricity consumption by a motor in a condition where a maximum output torque of an engine is restricted. A controller is configured to: calculate a current maximum torque of the engine when increasing a speed of the engine to achieve an acceleration demand; determine whether the current maximum torque of the engine is less than an inertia torque required to increase the speed of the engine; and adjust the reaction torque of the first motor to a value less than a predetermined value, if the current maximum torque of the engine is less than the inertia torque required to increase the speed of the engine.

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.

A control system for a vehicle includes an electronic control unit. The electronic control unit is configured to i) calculate a target supercharging pressure of an intake air such that, when an internal combustion engine is operated through the homogeneous charge compression ignition, the internal combustion engine achieves a required output while satisfying a predetermined requirement, ii) control an output of the internal combustion engine such that the output approaches the required output in accordance with an actual supercharging pressure in process of changing the actual supercharging pressure to the target supercharging pressure that is achieved by a supercharger, and iii) control a rotary machine such that an output of the rotary machine compensates for part or all of a differential output between the required output and the output in process of changing the actual supercharging pressure to the target supercharging pressure.

A method and system for anti-idling management for a vehicle including an anti-idling system (AIS) is disclosed. Based on inputs from different sources associated with the vehicle, the AIS determines when anti-idling management should be enabled in order to control the engine of the vehicle. In some embodiments, the AIS includes an AIS battery that can be used to power auxiliary vehicle components when the vehicle is stopped via anti-idling control management.

An HV-ECU calculates requested output torque Tec based on requested power and compares the requested output torque with controlled upper limit torque Teth. When requested output torque Tec has attained to controlled upper limit torque Teth, the HV-ECU restricts output torque of engine to controlled upper limit torque Teth and calculates actual output torque Ter at that time. Then, the HV-ECU calculates a difference (differential torque ΔTe) between controlled upper limit torque Teth and actual output torque Ter. The HV-ECU learns controlled upper limit torque Teth based on differential torque ΔTe.