EP0435374A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of controlling gear change in an automatic transmission
Assignee: Motors Liquidation Co
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Filing: 1990-12-13
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Granted: —
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Expires: 2010-12-13
Abstract
Abstract In an automatic transmission 16 upshifting is controlled by ramping down the pressure in an off-going clutch C1-CS associated with a high speed ratio and increasing the pressure in an on-coming clutch C1-CS associated with a lower speed ratio. The on-coming clutch C1-CS has commanded pressure at a maximum value for an initial fill time, a lower increasing ramp value during the ramp of the off-going clutch until the on-coming clutch starts to engage, and then a closed-loop control until the clutch reaches a synchronous speed. The closed-loop control parameter is on-coming clutch slip which is controlled to a calculated slip speed profile. Parameters for controlling the quality of a shift such as on-coming clutch initial pressure, off-going clutch initial pressure and on-coming clutch fill time are automatically adjustable during vehicle use to correct shift aberrations which degrade shift quality. A fast adjustment mode is in effect initially to calibrate the transmission control for the engine and vehicle. After a smooth shift is obtained only small adjustments are allowed.
Inventors
- 👤 Carl Albert Lentz
- 👤 Joseph Henry Hunter
- 👤 Jeffrey Kurt Runde
- 👤 Christopher Russell Wiles
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 18:34
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/04; F16H61/06; F16H61/061; F16H2061/0075; F16H2061/0078; F16H2061/0477; F16H59/00; F16H59/36; F16H59/46
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
213 words
A method of controlling the change in an automatic transmission for a vehicle from an off-going fluid pressure operated torque transmitting device (C1-C5) associated with a first speed ratio to an on-coming fluid pressure operated torque transmitting device (C1-C5) associated with a second speed ratio, wherein the off-going torque transmitting device is disengaged substantially concurrently with the engagement of the on-coming torque transmitting device, the automatic transmission including an input (22) and an output (24); the method comprising the steps of establishing a desired pattern of input and output speed functions for the change; disengaging the off-going torque transmitting device (C1-C5) by reducing its pre-change operating pressure on the basis of initial values; engaging the on-coming torque transmitting device (C1-C5) by supplying it with an initial on-coming pressure, and thereafter controlling the on-coming pressure by means of substantially closed-loop control; determining the difference between initial and final closed-loop on-coming pressures, to detect any aberration; and, if the pressure difference exceeds a threshold value, adjusting a stored parameter corresponding to the initial on-coming pressure by an amount related to the difference so as to establish a new initial on-coming pressure for use in a subsequent change so as to reduce the difference and to achieve the desired pattern of input and output speed functions.
Claim 2
Independent Claim
246 words
A method of controlling the change in an automatic transmission for a vehicle from an off-going fluid pressure operated torque transmitting device (C1-C5) associated with a first speed ratio to an on-coming fluid pressure operated torque transmitting device (C1-C5) associated with a second speed ratio, wherein the off-going torque transmitting device is disengaged substantially concurrently with the engagement of the on-coming torque transmitting device, the automatic transmission including an input (22) and an output (24); the method comprising the steps of establishing a desired pattern of input and output speed functions for the change; disengaging the off-going torque transmitting device (C1-C5) by reducing its pre-change operating pressure on the basis of initial values, and engaging the on-coming torque transmitting device (C1-C5) by supplying it with an initial on-coming pressure related to initial values, the initial values affecting the input and output speed functions and being calibrated to approximate the desired pattern; monitoring the transmission input and output speeds and comparing a measured speed function pattern with the desired pattern to detect any aberration; on detection of an aberration carrying out a first adjustment on a stored parameter related to the initial value responsible for such aberration by calculating the change required substantially to eliminate the aberration and altering the stored parameter on the basis thereof; and thereafter when such an aberration is detected in a subsequent change, carrying out a subsequent adjustment of the stored parameter by a small amount to correct the said initial value.
Claim 3
Dependent Claim
48 words
A method according to claim 2, wherein once the first adjustment of the stored parameter is carried out and no aberration is detected in a subsequent change, a further first adjustment is only carried out following the detection of an aberration in at least two consecutive subsequent changes.
Claim 4
Independent Claim
240 words
A method of controlling the change in an automatic transmission for a vehicle from an off-going fluid pressure operated torque transmitting device (C1-C5) associated with a first speed ratio to an on-coming fluid pressure operated torque transmitting device (C1-C5) associated with a second speed ratio, wherein the off-going torque transmitting device is disengaged substantially concurrently with the engagement of the on-coming torque transmitting device, the automatic transmission including an input (22) and an output (24); the method comprising the steps of establishing a desired pattern of input and output speed functions for the change; disengaging the off-going torque transmitting device (C1-C5) by reducing its pre-change operating pressure to an initial off-going pressure on the basis of an initial value and then decreasing the off-going pressure progressively to a final value; engaging the on-coming torque transmitting device (C1-C5) by supplying it with an initial on-coming pressure according to initial values, the values affecting the pattern of the input and output speed functions and being calibrated to approximate the desired pattern; sensing an event displaced in time from the pattern which results from an incorrect off-going ramp pressure; comparing the final value of the off-going pressure to the value at the desired time of the event to derive a pressure difference; and adjusting a stored parameter related to the initial off-going pressure to change the initial off-going pressure value by the derived pressure difference substantially to correct the time of the event.
Claim 5
Dependent Claim
76 words
A method according to claim 4, including the steps of inhibiting the derivation of the pressure difference and the adjustment of the stored parameter when a change from the first speed ratio to the second speed ratio occurs substantially without any aberration, and when an aberration is detected in a subsequent change from the first speed ratio to the second speed ratio, adjusting the stored parameter by a small increment to correct the initial off-going pressure.
Claim 6
Independent Claim
252 words
A method of controlling the change in an automatic transmission for a vehicle from an off-going fluid pressure operated torque transmitting device (C1-C5) associated with a higher speed ratio to an on-coming fluid pressure operated torque transmitting device (C1-C5) associated with a lower speed ratio wherein the off-going torque transmitting device is disengaged substantially concurrently with the engagement of the on-coming torque transmitting device, the automatic transmission comprising an input (22) and an output (24); the method comprising the steps of disengaging the off-going torque transmitting device (C1-C5) by reducing its pre-change operating pressure to a predefined initial off-going pressure, and thereafter effecting a further progressive reduction of the off-going pressure from the initial off-going pressure to complete disengagement of the off-going torque transmitting device; engaging the on-coming torque transmitting device (C1-C5) by supplying it with on-coming pressure for a predetermined on-coming period and thereafter controlling the on-coming pressure to effect a progressive engagement of the on-coming torque transmitting device; monitoring the transmission input and output speeds to detect an aberrant occurrence of a predefined event; adjusting a stored parameter related to the predefined initial off-going pressure so as to increase the initial off-going pressure in response to the occurrence of flare in the transmission input speed during the on-coming period, indicative of the initial off-coming pressure being too low; and adjusting the stored parameter so as to decrease the initial off-going pressure in response to the occurrence of an input speed change indicative of the initial off-going pressure being too high.
Claim 7
Dependent Claim
76 words
A method according to claim 6, wherein the step of adjusting the stored parameter comprises the steps of adjusting the stored parameter to a first value, being a relatively large amount calculated from the times of occurrence of a plurality of the predetermined events during previous changes, prior to a non-aberrant change so as to obtain a non-aberrant change, and to a second value, being a relatively smaller amount after the occurrence of a non-aberrant change.
Claim 8
Dependent Claim
80 words
A method according to claim 6 or 7, wherein the step of adjusting the stored parameter so as to decrease the initial off-going pressure includes the steps of detecting a decrease in transmission input speed after the on-coming period and prior to pulldown, or detecting pulldown more than a prescribed time after the on-coming period, wherein pulldown occurs when the input speed is reduced to substantially less than the product of the transmission output speed and the higher speed ratio.
Claim 9
Dependent Claim
53 words
A method according to claim 6, 7 or 8, wherein an amount by which the stored parameter is decreased is calculated as a function of the difference between the controlled on-coming pressure at the time of the aberrant predefined event and the controlled on-coming pressure at the desired time of the predefined event.
Claim 10
Dependent Claim
53 words
A method according to claim 6, 7 or 8, wherein an amount by which the stored parameter is increased is calculated as a function of the difference between the controlled on-coming pressure at the time of the aberrant predefined event and the controlled on-coming pressure at the desired time of the predefined event.
Claim 11
Independent Claim
49 words
A method according to any one of claims 6 to 10, including the step of adjusting a stored parameter related to the predefined on-coming period so as to increase the on-coming period in response to the occurrence of input speed flare during the change and after the on-coming period.
Claim 12
Dependent Claim
39 words
A method according to claim 11, wherein the amount by which the on-coming period is increased is calculated from the difference between the time at which input speed is at a maximum and the end of the on-coming period.
Claim 13
Independent Claim
44 words
A method according to any one of claims 6 to 12, wherein following the occurrence of an adjustment which decreases the predefined on-coming period, the stored parameter related to the predefined initial off-going pressure is increased so as to increase the initial off-going pressure.
Claim 14
Independent Claim
60 words
A method according to any one of claims 6 to 13, wherein when the input speed change occurs during a closed throttle condition and is accompanied by input deceleration, decrease of the stored parameter related to the initial off-going pressure is inhibited and the stored parameter related to the on-coming period is adjusted so as to decrease the on-coming period.
Claim 15
Independent Claim
73 words
A method according to any one of claims 6 to 14, including the steps of detecting pulldown during the on-coming period, wherein pulldown is determined to have occurred when the input speed is substantially less than the product of the transmission output speed and the higher speed ratio; and in response to the detection of pulldown, the stored parameter related to the on-coming period is adjusted so as to decrease the on-coming period.
Claim 16
Dependent Claim
33 words
A method according to claim 15, wherein the amount by which the on-coming period is decreased is related to the difference between the time of pulldown and the end of the on-coming period.
Claim 17
Independent Claim
319 words
A method of controlling the change in an automatic transmission for a vehicle from an off-going fluid pressure operated torque transmitting device (C1-C5) associated with a higher speed ratio to an on-coming fluid pressure operated torque transmitting device (C1-C5) associated with a lower speed ratio wherein the off-going torque transmitting device is disengaged substantially concurrently with the engagement of the on-coming torque transmitting device, the automatic transmission comprising an input (22) and an output (24); the method comprising the steps of disengaging the off-going torque transmitting device (C1-C5) by reducing its pre-change operating pressure to a predefined initial off-going pressure, and thereafter effecting a further progressive reduction of the off-going pressure from the initial off-going pressure to complete disengagement of the off-going torque transmitting device; engaging the on-coming torque transmitting device (C1-C5) by supplying it with on-coming pressure for a predetermined on-coming period up to an initial on-coming pressure and thereafter controlling the on-coming pressure to effect a progressive engagement of the on-coming torque transmitting device; carrying out a closed-loop control period in which the on-coming pressure is controlled on the basis of the difference between the rate of slip of the on-coming torque transmitting device and a programmed slip rate until the input speed substantially reaches a target value corresponding to the output speed at the lower ratio; adjusting a stored parameter related to the initial on-coming pressure following completion of the change when it is determined either that the on-coming pressure at the end of the closed-loop control period is greater than the on-coming pressure at the beginning of the closed-loop control period by more than a first threshold value or that the on-coming pressure at the end of the closed-loop control period is less than the on-coming pressure at the beginning of the closed loop period by more than a second threshold value, the adjustment enabling subsequent changes to produce more accurately the desired slip rate.
Claim 18
Dependent Claim
76 words
A method according to claim 17, wherein the step of adjusting the stored parameter comprises the steps of adjusting the stored parameter to a first value being a relatively large amount calculated from the on-coming pressures at the times of a plurality of predefined events during previous changes, prior to a non-aberrant change so as to obtain a non-aberrant change, and to a second value, being a relatively smaller amount after the occurrence of non-aberrant change.
Claim 19
Dependent Claim
63 words
A method according to claim 17, wherein the amount by which the stored parameter is adjusted is determined by the steps of calculating the difference between the on-coming pressure at the end of the closed-loop control period and the on-coming pressure at the beginning of the closed-loop control period, and determining the amount of adjustment as a function of the calculated pressure difference.
Claim 20
Independent Claim
271 words
A method of controlling the change in an automatic transmission for a vehicle from an off-going fluid pressure operated torque transmitting device (C1-C5) associated with a higher speed ratio to an on-coming fluid pressure operated torque transmitting device (C1-C5) associated with a lower speed ratio wherein the off-going torque transmitting device is disengaged substantially concurrently with the engagement of the on-coming torque transmitting device, the automatic transmission comprising an input (22) and an output (24); the method comprising the steps of disengaging the off-going torque transmitting device (GIGS) by reducing its pre-change operating pressure to a predefined initial off-going pressure, and thereafter effecting a further progressive reduction of the off-going pressure from the initial off-going pressure to complete disengagement of the off-going torque transmitting device; engaging the on-coming torque transmitting device (C1-C5) by supplying it with on-coming pressure for a predefined on-coming period up to an initial on-coming pressure and thereafter controlling the on-coming pressure to effect a progressive engagement of the on-coming torque transmitting device; carrying out a closed-loop control period in which the on-coming pressure is controlled so as to bring slip of the on-coming torque transmitting device substantially into correspondence with a predefined slip profile appropriate for lowering the input speed to a target value related to the output speed at the lower ratio; and increasing a stored parameter related to the initial on-coming pressure following completion of the change if the input speed falls substantially below the target speed during the closed-loop control period to ensure that in subsequent changes the input speed substantially reaches the target speed at the end of the respective closed-loop control period.
References Cited (Backward Citations)
No citation records indexed.
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