Shift control for a two-axis automatic transmission for a vehicle
First Claim
1. A shift control method for an automatic transmission provided with a primary shift portion and a secondary shift portion, comprising:
- (a) starting shift control for the secondary shift portion by determining control start timing for friction elements of the primary and secondary shift portions based on vehicle operating conditions, if a shift signal is output, at the point of the output of the shift signal, and if shift control for the secondary shift portion is detected, starting shift control for the primary shift portion, and then determining a primary shift portion target change rate for feedback control of the primary shift portion and a secondary shift portion target change rate for feedback control of the secondary shift portion;
(b) performing feedback control of the primary shift portion according to a change rate of a difference between an input speed and an output speed of the primary shift portion and the primary shift portion target change rate, and the feedback control of the secondary shift portion according to a change rate of a turbine speed and the secondary shift portion target change rate; and
(c) completing a shift of the primary shift portion, then completing a shift of the secondary shift portion.
1 Assignment
0 Petitions
Accused Products
Abstract
A shift control method for an automatic transmission having a primary shift portion and a secondary shift portion is provided that comprises: starting, if a shift signal is output, a shift in the secondary shift portion, and then starting a shift in the primary shift portion; performing feedback control of duty ratios of friction element solenoids for the primary shift portion with a goal of approaching a change rate of a difference between an input speed and an output speed of the primary shift portion to a first target speed change rate, and simultaneously performing feedback control of duty ratios of friction element solenoids for the secondary shift portion with a goal of approaching a change rate of a turbine speed to a second target speed change rate; and completing the shift in the primary shift portion, and then completing the shift in the secondary shift portion.
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Citations
44 Claims
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1. A shift control method for an automatic transmission provided with a primary shift portion and a secondary shift portion, comprising:
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(a) starting shift control for the secondary shift portion by determining control start timing for friction elements of the primary and secondary shift portions based on vehicle operating conditions, if a shift signal is output, at the point of the output of the shift signal, and if shift control for the secondary shift portion is detected, starting shift control for the primary shift portion, and then determining a primary shift portion target change rate for feedback control of the primary shift portion and a secondary shift portion target change rate for feedback control of the secondary shift portion;
(b) performing feedback control of the primary shift portion according to a change rate of a difference between an input speed and an output speed of the primary shift portion and the primary shift portion target change rate, and the feedback control of the secondary shift portion according to a change rate of a turbine speed and the secondary shift portion target change rate; and
(c) completing a shift of the primary shift portion, then completing a shift of the secondary shift portion. - View Dependent Claims (2, 3, 4, 5)
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6. A shift control method for an automatic transmission that is provided with a primary shift portion and a secondary shift portion, comprising:
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(a) starting, if a shift signal is output, a shift in the secondary shift portion, and then starting a shift in the primary shift portion;
(b) performing feedback control of output duty ratios for an on-coming friction element solenoid of the secondary shift portion with a goal of achieving a predetermined first input speed change rate, and simultaneously performing feedback control of output duty ratios for an off-going friction element solenoid of the primary shift portion with a goal of achieving a predetermined second input speed change rate; and
(c) completing the shift in the primary shift portion, and then completing the shift in the secondary shift portion. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. A shift control method for an automatic transmission having a primary shift portion and a secondary shift portion, said method comprising:
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starting shift control for said secondary shift portion and determining a secondary target speed change rate;
starting shift control for said primary shift portion after starting shift control for said secondary shift portion and determining a primary target speed change rate;
performing feedback control for said primary shift portion based on a comparison of a calculated speed change rate and said primary target speed change rate;
performing feedback control of said secondary shift portion simultaneously with said primary shift portion feedback control, the secondary shift portion feedback control being based on a comparison of a calculated change rate of turbine speed and said secondary target speed change rate; and
first completing shifting of said primary shift portion and then completing shifting of said secondary shift portion. - View Dependent Claims (43, 44)
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Specification