US 5,267,491 A · Control system of an automatic transmission

Abstract

The control system for an automatic transmission shifts the main transmission simultaneously with the auxiliary transmission at the time of a particular shift. At this time, a target gear ratio progress value of the auxiliary transmission is set for a gear ratio progress value indicative of a shift progress state of the main transmission. The main transmission is arranged so as to finish the shift control within a given target period of time, and the auxiliary transmission is arranged to implement the shift control by the feedback control so as to follow the target gear ratio progress value. The shift control of the auxiliary transmission is corrected by the learning control on the basis of a deviation between the target gear ratio progress value and the actual gear ratio progress value.

Claims29

Dependent claims

A control system for an automatic transmission with a main transmission and an auxiliary transmission connected thereto, so adapted as for each of said main transmission and auxiliary transmission to implement a shift by changing an operating state of a hydraulic friction coupling element thereof, said control system comprising:

target value setting means for setting a target value for a shift progress state in which the shift progresses at the time of the shift, when the shift of the automatic transmission as a whole is implemented by shifting said main transmission substantially together with said auxiliary transmission;
feedback control means for implementing feedback control for coupling pressure of said friction coupling element thereof so as to allow an actual shift progress state at the time of the particular shift to follow said target value;
and
first learning control means for correcting the coupling pressure of said friction coupling element of either of said main transmission or said auxiliary transmission by learning control on the basis of a deviation of said actual shift progress state for said target value.

1 more element

A control system for an automatic transmission with a main transmission and an auxiliary transmission connected thereto, each having a multiple shift gear mechanism and a hydraulic friction coupling element for shifting a passage for transmitting power of said multiple shift gear mechanism, said control system comprising:

feedforward control means for implementing feedforward control for a coupling pressure of said friction coupling element for said main transmission so as to finish the shift of said main transmission within a predetermined target time at the time of a particular shift when the automatic transmission is shifted as a whole by shifting said main transmission substantially together with said auxiliary transmission;
target gear ratio progress value determining means for determining a target gear ratio progress value of said auxiliary transmission on the basis of an actual gear ratio progress value of said main transmission;
feedback control means for implementing feedback control for coupling pressure of said friction coupling element thereof so as for a gear ratio progress value of said auxiliary transmission to follow said target gear ratio progress value at the time of the particular shift;
first learning control means for correcting a basic control value by said feedback control means by learning control on the basis of a feedback control correction amount by said feedback control means;
and
second learning control means for correcting a basic control value by said feedforward control means by learning control on the basis of an actual time of finishing the shift of said main transmission.

3 more elements

Dependencies are inferred from the claim text.

Control system of an automatic transmission

Life of this patent

Control system of an automatic transmission

Life of this patent

Abstract

Claims29