Clutch torque trajectory correction to provide torque hole filling during a ratio upshift
First Claim
1. A powertrain comprising:
- a multiple-ratio transmission with oncoming and off-going clutches for effecting a ratio-upshift;
a torque sensor for measuring an actual measured torque value for one of the off-going and oncoming clutches;
a shift controller configured for;
adjusting an estimated oncoming clutch torque in response to the actual measured torque value during a torque phase; and
releasing the off-going clutch if measured off-going clutch torque is less than a threshold.
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Abstract
A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated friction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a torque source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a torque source is modulated. A perceptible transmission output torque reduction during an upshift is avoided. Measured torque values are used during a torque phase of the upshift to correct an estimated oncoming friction element target torque so that transient torque disturbances at an oncoming clutch are avoided and torque transients at the output shaft are reduced.
52 Citations
20 Claims
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1. A powertrain comprising:
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a multiple-ratio transmission with oncoming and off-going clutches for effecting a ratio-upshift; a torque sensor for measuring an actual measured torque value for one of the off-going and oncoming clutches; a shift controller configured for; adjusting an estimated oncoming clutch torque in response to the actual measured torque value during a torque phase; and releasing the off-going clutch if measured off-going clutch torque is less than a threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for controlling oncoming and off-going clutches in a multiple-ratio transmission comprising:
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increasing torque input at a controlled rate during a torque phase of a ratio-upshift; controlling torque input to achieve a desired off-going clutch slip; measuring oncoming and off-going clutch torques; and setting an oncoming feed-forward clutch torque as a function of chosen output shaft torque and a measured off-going clutch torque, followed by an inertia phase of the upshift. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method for controlling oncoming and off-going clutches in a multiple-ratio transmission comprising:
- setting a target input torque during a torque phase of an upshift based on a desired output shaft torque and a desired input shaft slip torque;
calculating an oncoming clutch torque target as a function of a change in off-going clutch torque during the torque phase and a change in torque of the input shaft; ramping the oncoming clutch torque to the torque target; measuring an actual oncoming clutch torque during the torque phase; adjusting the target input torque based on the actual measured oncoming clutch torque; and ramping input torque toward the adjusted target input torque. - View Dependent Claims (17, 18, 19, 20)
- setting a target input torque during a torque phase of an upshift based on a desired output shaft torque and a desired input shaft slip torque;
Specification