Control device of vehicle power transmission device

1. A control device of a vehicle power transmission device having an automatic transmission shifted by engagement and release of hydraulic friction engagement devices to selectively establish a plurality of gear stages and an electric motor coupled to an input shaft of the automatic transmission in a power transmittable manner, the control device executing a clutch-to-clutch shift while performing regeneration through the electric motor at the time of a coast down shift of the automatic transmission,

the control device completing regenerative torque reduction control to reduce a regenerative torque of the electric motor in a torque phase of the coast down shift before start of the torque phase in accordance with a drop-off of an output torque of the vehicle power transmission device.

2. The control device of a vehicle power transmission device of claim 1 , wherein the regenerative torque reduction control is started at the time of output of a shift command for executing the clutch-to-clutch shift.

3. The control device of a vehicle power transmission device of claim 2 , wherein the regenerative torque reduction control is provided within a range of a predetermined regenerative torque change rate.

4. The control device of a vehicle power transmission device of claim 2 , wherein learning control of an oil pressure command value of the hydraulic friction engagement devices involved with the clutch-to-clutch shift is provided such that a change in input shaft rotation speed of the automatic transmission converges to a target value or such that an undershoot amount of the input shaft rotation speed of the automatic transmission converges during the coast down shift of the automatic transmission.

5. The control device of a vehicle power transmission device of claim 2 , wherein

the vehicle power transmission device includes a differential portion coupled to an input shaft of the automatic transmission in a power transmittable manner, wherein

the differential portion is an electric differential device having the electric motor coupled in a power transmittable manner on the output side and having a differential mechanism coupled to an engine in a power transmittable manner and a differential electric motor coupled to the differential mechanism in a power transmittable manner such that a differential state of the differential mechanism is controlled by controlling an operating state of the differential electric motor, and wherein

if the differential electric motor outputs a regenerative torque or a drive torque in addition to regeneration through the electric motor at the time of a coast down shift of the automatic transmission, an input torque change rate of the automatic transmission in the regenerative torque reduction control is reduced as compared to the case that the differential electric motor does not output the regenerative torque or the drive torque.

6. The control device of a vehicle power transmission device of claim 5 , wherein if the input torque change rate in the regenerative torque reduction control is reduced, start timing of the regenerative torque reduction control is made earlier as compared to the case of not reducing the input torque change rate.

7. The control device of a vehicle power transmission device of claim 5 , wherein that the differential electric motor outputs the drive torque means that a portion or whole of regenerative electric power from the electric motor is consumed by the differential electric motor because of input limitation of an electric storage device giving/receiving electric power to/from the differential electric motor and the electric motor.

8. The control device of a vehicle power transmission device of claim 1 , wherein the regenerative torque reduction control is started when output of a shift command for executing the clutch-to-clutch shift is predicted.

9. The control device of a vehicle power transmission device of claim 8 , wherein the regenerative torque reduction control is provided within a range of a predetermined regenerative torque change rate.

10. The control device of a vehicle power transmission device of claim 8 , wherein learning control of an oil pressure command value of the hydraulic friction engagement devices involved with the clutch-to-clutch shift is provided such that a change in input shaft rotation speed of the automatic transmission converges to a target value or such that an undershoot amount of the input shaft rotation speed of the automatic transmission converges during the coast down shift of the automatic transmission.

11. The control device of a vehicle power transmission device of claim 8 , wherein

the vehicle power transmission device includes a differential portion coupled to an input shaft of the automatic transmission in a power transmittable manner, wherein

the differential portion is an electric differential device having the electric motor coupled in a power transmittable manner on the output side and having a differential mechanism coupled to an engine in a power transmittable manner and a differential electric motor coupled to the differential mechanism in a power transmittable manner such that a differential state of the differential mechanism is controlled by controlling an operating state of the differential electric motor, and wherein

if the differential electric motor outputs a regenerative torque or a drive torque in addition to regeneration through the electric motor at the time of a coast down shift of the automatic transmission, an input torque change rate of the automatic transmission in the regenerative torque reduction control is reduced as compared to the case that the differential electric motor does not output the regenerative torque or the drive torque.

12. The control device of a vehicle power transmission device of claim 11 , wherein if the input torque change rate in the regenerative torque reduction control is reduced, start timing of the regenerative torque reduction control is made earlier as compared to the case of not reducing the input torque change rate.

13. The control device of a vehicle power transmission device of claim 11 , wherein that the differential electric motor outputs the drive torque means that a portion or whole of regenerative electric power from the electric motor is consumed by the differential electric motor because of input limitation of an electric storage device giving/receiving electric power to/from the differential electric motor and the electric motor.

14. The control device of a vehicle power transmission device of claim 1 , wherein the regenerative torque reduction control is provided within a range of a predetermined regenerative torque change rate.

15. The control device of a vehicle power transmission device of claim 1 , wherein learning control of an oil pressure command value of the hydraulic friction engagement devices involved with the clutch-to-clutch shift is provided such that a change in input shaft rotation speed of the automatic transmission converges to a target value or such that an undershoot amount of the input shaft rotation speed of the automatic transmission converges during the coast down shift of the automatic transmission.

16. The control device of a vehicle power transmission device of claim 1 , wherein

the vehicle power transmission device includes a differential portion coupled to an input shaft of the automatic transmission in a power transmittable manner, wherein

the differential portion is an electric differential device having the electric motor coupled in a power transmittable manner on the output side and having a differential mechanism coupled to an engine in a power transmittable manner and a differential electric motor coupled to the differential mechanism in a power transmittable manner such that a differential state of the differential mechanism is controlled by controlling an operating state of the differential electric motor, and wherein

if the differential electric motor outputs a regenerative torque or a drive torque in addition to regeneration through the electric motor at the time of a coast down shift of the automatic transmission, an input torque change rate of the automatic transmission in the regenerative torque reduction control is reduced as compared to the case that the differential electric motor does not output the regenerative torque or the drive torque.

17. The control device of a vehicle power transmission device of claim 16 , wherein if the input torque change rate in the regenerative torque reduction control is reduced, start timing of the regenerative torque reduction control is made earlier as compared to the case of not reducing the input torque change rate.

18. The control device of a vehicle power transmission device of claim 16 , wherein that the differential electric motor outputs the drive torque means that a portion or whole of regenerative electric power from the electric motor is consumed by the differential electric motor because of input limitation of an electric storage device giving/receiving electric power to/from the differential electric motor and the electric motor.