Control device and control method of automatic transmission

Abstract

There is a control device and a control method of an automatic transmission including; a plurality of friction engagement devices; a plurality of solenoids whose electrification amount supplied is controlled to adjust engagement force of the friction engagement devices, and which are switched between electrification and non-electrification so as to switch between speed change steps of the automatic transmission; and an abnormality determiner that performs abnormality determination regarding the solenoids based on predetermined condition. The solenoids operate when supplied with an electrification amount that exceeds a predetermined value. The abnormality determination is performed by supplying a solenoid put in a non-electrified state, of the solenoids, with as electrification amount that is less than or equal to the predetermined value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The features, advantages thereof, and technical and industrial significance of this invention will be better understood by reading the following detailed description of preferred embodiments of the invention, when considered in connection with the accompanying drawings, in which:

FIG. 1 is a diagram illustrating a hybrid drive device in accordance with an embodiment of the invention, and is a block diagram illustrating portions of a control system that is provided in the vehicle for controlling the hybrid drive device and the like;

FIG. 2 is an alignment chart showing a relative relationship in rotation speed among the rotating elements of a single-pinion type planetary gear device that functions as a torque combining-distributing mechanism;

FIG. 3 is an alignment chart representing an interrelationship among the rotating elements of a Ravigneaux type planetary gear mechanism that constitutes a transmission;

FIG. 4 shows a shift-purpose hydraulic control circuit for automatically controlling the shift of the transmission by engaging and releasing a first brake and a second brake;

FIG. 5 is a diagram showing a valve characteristic of a normally closed type first linear solenoid valve that establishes an open valve (communicated) state between the input port and the output port during a non-electrified state;

FIG. 6 is a diagram showing a valve characteristic of a normally open type second linear solenoid valve that establishes a closed valve (shut-off) state between the input port and the output port during the non-electrified state;

FIG. 7 is a table illustrating operations of a hydraulic control circuit;

FIG. 8 is a functional block diagram illustrating portions of control functions of electronic control devices shown in FIG. 1;

FIG. 9 is a shift chart that is used in a shift control of the transmission performed by the electronic control devices shown in FIG. 1; and

FIG. 10 is a flowchart illustrating portions of the control operations of the electronic control devices shown in FIG. 1, that is, a control operation for performing the abnormality determination when both the first linear solenoid valve and the second linear solenoid valve are in a non-excited state.

Claims

1. A control device of an automatic transmission, comprising: a plurality of friction engagement devices;a plurality of solenoids whose electrification amount supplied is controlled to adjust engagement force of the friction engagement devices, and which are switched between electrification and non-electrification so as to switch between speed change steps of the automatic transmission; andan abnormality determiner that performs abnormality determination regarding the solenoids based on predetermined condition,

2. The control device of the automatic transmission according to claim 1, wherein each solenoid has a dead band where the solenoid does not operate when the electrification amount supplied is less than or equal to the predetermined value.

3. The control device of the automatic transmission according to claim 1, wherein the abnormality determiner performs the abnormality determination during a run on a speed change step that is achieved when the solenoids are put into a non-electrified state.

4. The control device of the automatic transmission according to claim 3, wherein at least one solenoid of the solenoids is switched in valve state to a position for completely engaging the friction engagement devices when put into the non-electrified state.

5. In an automatic transmission that switches between speed change steps by switching between electrification and non-electrification of a plurality of solenoids whose electrification amount supplied is controlled to adjust engagement force of a plurality of friction engagement devices, a control method of the automatic transmission which control method performs abnormality determination regarding the solenoids, comprising operating the solenoids by supplying thereto an electrification amount that exceeds a predetermined value; andperforming the abnormality determination by supplying a solenoid put in a non-electrified state, of the solenoids, with an electrification amount that is less than or equal to the predetermined value.