A hybrid vehicle includes an electronic control unit configured to: set a target rotation speed of an engine based on a vehicle speed and a shift position; set a driving force when an upper-limit power is output to a drive shaft as an upper-limit driving force; set a target engine power such that the smaller of the upper-limit driving force and the required driving force is output to the drive shaft; and control the engine, the first motor, and the second motor such that the engine to rotate at the target rotation speed and to output the target power. At this time, the upper-limit power is set to be lower when a coolant temperature of the engine is low than when the coolant temperature is high.

A drivability target engine speed is set based on a shift stage based on an accelerator opening level and a vehicle speed and the vehicle speed, and a base driving force is set based on an accelerator required driving force and the drivability target engine speed. When an elapsed time after an accelerator depression amount increases is less than a threshold value, a correction driving force is set based on an increase in accelerator depression amount and an engine, a first motor, and a second motor are controlled such that an effective driving force obtained by adding the correction driving force to the base driving force is output to a drive shaft for a hybrid vehicle to travel.

A drivability target engine speed is set based on a shift stage based on an accelerator opening level and a vehicle speed and the vehicle speed, and a base driving force is set based on an accelerator required driving force and the drivability target engine speed. When an elapsed time after an accelerator depression amount increases is less than a threshold value, a correction driving force is set based on an increase in accelerator depression amount and an engine, a first motor, and a second motor are controlled such that an effective driving force obtained by adding the correction driving force to the base driving force is output to a drive shaft for a hybrid vehicle to travel.

In a vehicle including an engine, drive wheels, a power transmission system, and an electronic control unit, during shifting of an automatic transmission, a hydraulic command value of a clutch is set to a higher value as an engine power command value is larger, so that a shift or change of the speed ratio proceeds in an electronic continuously variable transmission and the automatic transmission, in accordance with engine power as a product of the engine speed and engine torque, rather than torque of the engine, etc.

A plurality of virtual gear positions are established by an electric continuously variable transmission, and the number of speeds of the virtual gear positions is equal to or larger than the number of speeds of mechanical gear positions of a mechanical stepwise variable transmission. One or two or more virtual gear positions is/are assigned to each mechanical gear position, and shifts among the mechanical gear positions are performed in the same timing as the shift timing of the virtual gear positions. Thus, shifting of the mechanical stepwise variable transmission is accompanied by change of the engine speed Ne, and the driver is less likely to feel uncomfortable even if shift shock occurs during shifting of the mechanical stepwise variable transmission.

A plurality of virtual gear positions are established by an electric continuously variable transmission, and the number of speeds of the virtual gear positions is equal to or larger than the number of speeds of mechanical gear positions of a mechanical stepwise variable transmission. One or two or more virtual gear positions is/are assigned to each mechanical gear position, and shifts among the mechanical gear positions are performed in the same timing as the shift timing of the virtual gear positions. Thus, shifting of the mechanical stepwise variable transmission is accompanied by change of the engine speed Ne, and the driver is less likely to feel uncomfortable even if shift shock occurs during shifting of the mechanical stepwise variable transmission.

A hybrid vehicle drive device includes a power transmission mechanism including a transmission coupled to an engine output shaft, a clutch coupled to a transmission output shaft, a first gear coupled to a clutch output shaft, a final reduction gear that constantly meshes with the first gear, a drive shaft coupled to the final reduction gear, a first rotary element coupled to an electric motor, and a second rotary element that meshes with the final reduction gear and rotates in accordance with the rotation of the rotary element. The power transmission mechanism is disposed so that, when viewed from the rotational axis direction of each gear, a line that connects the rotational axis of the first rotary element and the rotational axis of the second rotary element is inclined to the first gear side in relation to the vertical direction of the vehicle when mounted to a vehicle.

A hybrid vehicle drive device includes a power transmission mechanism including a transmission coupled to an engine output shaft, a clutch coupled to a transmission output shaft, a first gear coupled to a clutch output shaft, a final reduction gear that constantly meshes with the first gear, a drive shaft coupled to the final reduction gear, a first rotary element coupled to an electric motor, and a second rotary element that meshes with the final reduction gear and rotates in accordance with the rotation of the rotary element. The power transmission mechanism is disposed so that, when viewed from the rotational axis direction of each gear, a line that connects the rotational axis of the first rotary element and the rotational axis of the second rotary element is inclined to the first gear side in relation to the vertical direction of the vehicle when mounted to a vehicle.

A method is provided to control a hybrid powertrain comprising an internal combustion engine; a gearbox with input and output shafts; a range gearbox, connected to the output shaft; a first planetary gear, connected to the input shaft; a second planetary gear, connected to the first planetary gear; a first electrical machine, connected to the first planetary gear; a second electrical machine, connected to the second planetary gear; at least one gear pair, connected with the first planetary gear and the output shaft; and at least one gear pair, connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected with the first planetary gear via the input shaft. The method comprises the steps: a) engaging a gear by way of connecting two rotatable components in the first planetary gear; b) connecting the at least one gear pair, connected with the second planetary gear and the output shaft; c) connecting a sixth gear pair, arranged between a countershaft and the range gearbox with the countershaft, so that the countershaft is connected with the output shaft via the range gearbox; d) controlling the range gearbox from a low range position to a neutral state, in which no torque transmission occurs through the range gearbox; e) controlling two rotatable components in the range gearbox towards achieving a synchronized rotational speed with the assistance of the first electrical machine; f) connecting the rotatable components with the use of a shiftable third clutch device; and g) engaging a gear by way of connecting two rotatable components in the second planetary gear.

A method is provided to control a hybrid powertrain comprising an internal combustion engine; a gearbox with input and output shafts; a range gearbox, connected to the output shaft; a first planetary gear, connected to the input shaft; a second planetary gear, connected to the first planetary gear; a first electrical machine, connected to the first planetary gear; a second electrical machine, connected to the second planetary gear; at least one gear pair, connected with the first planetary gear and the output shaft; and at least one gear pair, connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected with the first planetary gear via the input shaft. The method comprises the steps: a) engaging a gear by way of connecting two rotatable components in the first planetary gear; b) connecting the at least one gear pair, connected with the second planetary gear and the output shaft; c) connecting a sixth gear pair, arranged between a countershaft and the range gearbox with the countershaft, so that the countershaft is connected with the output shaft via the range gearbox; d) controlling the range gearbox from a low range position to a neutral state, in which no torque transmission occurs through the range gearbox; e) controlling two rotatable components in the range gearbox towards achieving a synchronized rotational speed with the assistance of the first electrical machine; f) connecting the rotatable components with the use of a shiftable third clutch device; and g) engaging a gear by way of connecting two rotatable components in the second planetary gear.