Methods and system for improving hybrid vehicle transmission gear shifting

Patent metadata

Field	Value
Publication number	US-2018257635-A1
Application number	US-201715454983-A
Country	US
Kind code	A1
Filing date	Mar 9, 2017
Priority date	Mar 9, 2017
Publication date	Sep 13, 2018
Grant date	—

Abstract

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, a rear drive unit electric machine, an integrated starter/generator, and a transmission are described. In one example, inertia torque compensation is provided to counter inertia torque during a power-on upshift.

First claim

1 . A driveline operating method, comprising:
reducing transmission input torque to a transmission instantaneous upper threshold torque during a power-on upshift via a controller, the transmission instantaneous upper threshold responsive to reported transmission torque ratio, transmission torque ratio in a new gear, transmission inertia, and a desired duration of the transmission upshift.

2 . The method of claim 1 , where the reported transmission torque ratio is determined from transmission input speed and transmission output speed, and further comprising;
Reducing transmission input torque to less than a transmission hardware upper threshold.

3 . The method of claim 1 , where the reported transmission torque ratio is determined clutch capacity of an on-coming clutch and a torque ratio of the transmission when the transmission is engaged in the new gear.

4 . The method of claim 1 , where the new gear is a gear engaged immediately after the power-on upshift is complete.

5 . The method of claim 1 , where torque of an engine is adjusted to a value of the transmission instantaneous upper threshold.

6 . The method of claim 1 , where reducing the transmission input torque includes reducing torque of a rear drive unit electric machine or a torque of a motor positioned directly downstream of a transmission output or an electric machine included with an independently driven axle.

7 . The method of claim 1 , where reducing the transmission input torque includes reducing a magnitude of a regenerative torque of a rear drive unit electric machine when the rear drive unit is providing electric power to an electric power storage unit.

8 . A driveline operating method, comprising:
reducing transmission input torque to a transmission instantaneous upper threshold torque during a power-on upshift via a controller, the transmission instantaneous upper threshold a function of reported transmission torque ratio, transmission torque ratio in a new gear, transmission inertia, and a desired duration of the transmission upshift; and commanding a torque capacity of an on-coming clutch via the controller in response to a torque ratio of a transmission when the transmission is engaged in a new gear and in response to a reported torque ratio of the transmission.

9 . The method of claim 8 , further comprising commanding the torque capacity of the on-coming clutch in response to an estimated transmission input torque and an estimated equivalent transmission input torque.

10 . The method of claim 9 , where the estimated equivalent transmission torque is responsive to torque of a rear drive unit electric machine or torque of a motor positioned directly downstream of a transmission or an electric machine included with an independently driven axle.

11 . The method of claim 10 , where the estimated transmission input torque is responsive to transmission clutch slippage.

12 . The method of claim 8 , where the transmission input torque is reduced via reducing torque of a rear drive unit electric machine when the rear drive unit is providing positive torque to the driveline.

13 . The method of claim 8 , where reducing transmission input torque includes providing a regenerative braking torque via a rear drive unit electric machine.

14 . The method of claim 8 , where reducing transmission input torque includes reducing engine and integrated starter/generator torque without adjusting a regenerative braking torque of a rear drive unit electric machine while the rear drive unit electric machine is providing a regenerative braking torque.

15 . A driveline operating method, comprising:
adjusting a transmission instantaneous lower torque threshold via a controller in response to a reported transmission torque ratio, a transmission torque ratio in an old gear, and a transmission input torque without modification, the reported transmission torque ratio responsive to an off-going clutch torque capacity and an estimated transmission input torque; and adjusting torque of an engine responsive to the transmission instantaneous lower torque threshold via the controller.

16 . The method of claim 15 , further comprising adjusting a torque capacity of a transmission clutch in response to the reported transmission torque ratio.

17 . In another representation, the method of claim 15 , further comprises providing the reported torque ratio during engine starting responsive to clutch torque capacities of two transmission clutches.

18 . The method of claim 17 , where the clutch torque capacities of the two transmission clutches are non-zero.

19 . The method of claim 17 , further comprising the reported torque ratio being responsive to two torque ratios of a transmission.

20 . The method of claim 19 , where a first of the two torque ratios is a torque ratio of the transmission operating in a desired gear.

Assignees

• Ford Global Tech Llc

Inventors

• Meyer Jason
• Doering Jeffrey Allen
• Wang Xiaoyong
• Shelton Matthew John
• Teslak Christopher John
• Miller Kenneth James

Classifications

• B60W2710/027

  Clutch torque · CPC title

• B60W2510/0241

  Clutch slip, i.e. difference between input and output speeds · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60W2510/1095

  Inertia · CPC title

• Y10S903/93

  Conjoint control of different elements · CPC title