Automatic transmission controlling apparatus and method

Abstract

An ECU executes a program including a step (S102) of starting monitoring of the rotational speed of the turbine and the rotational speed of output shaft when direct gear change is started (YES at step S100), a step (S106) of making a control of completely releasing a release element (1), a step (S110) of lowering the control pressure of the release element (2) to a predetermined control pressure,a step (S114) of starting engagement control of an engagement element (1) when a set time Ts (1) elapses (YES at step S112), and a step (S120) of making a control of completely releasing the release element (2) when a set time Ts (2) elapses (YES at step S118), and a step (S124) of starting engagement control of the engagement element (2) if the rotational speed NT of the turbine is a value equalto or more than the remainder of the subtraction, after-gear-change gear position synchronous rotational speed - set value Ns (YES at step S122).

Description

technical field [0001] The present invention relates to control of an automatic transmission, and in particular to control of a speed change that requires replacement of two or more frictional engagement elements in a short time while suppressing a shift shock. Background technique [0002] The components of the automatic transmission of a vehicle include planetary gears and friction engagement elements, which are composed of rotating elements such as sun gears, ring gears, and planetary gears. In such an automatic transmission, any one of a plurality of gear stages is formed by switching a combination of engaged frictional engagement elements to switch a transmission path of torque transmitted from an engine. In particular, in an automatic transmission with a large number of gear stages (for example, a 6-speed automatic transmission), a plurality of clutch elements as input elements and brake elements as counterforce elements are respectively provided. [0003] In such an ...

AI Technical Summary

Problems solved by technology

That is, after the intermediate gear stage is completely formed by switching from the first friction element to the fourth friction element, the switching from the second friction element to the third friction element may be performed, so the period of the shifting operation may become longer.

[0007] In addition, when the first friction element and the second friction element are replaced in parallel, from the time the first friction element and the second friction element are released until the third friction element and the fourth friction element are engaged, in the automatic transmission, there is There are rotating elements that cannot detect the rotational speed, so there may be a shift shock when the third friction element and the fourth friction element are engaged

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