Method for controlling double-clutch speed change device

Abstract

A method of controlling the torque transferred across each of the two clutches of a dual clutch transmission during a two-gear positive downshift, wherein the first of the two clutches drives an initial gear and the final gear and the second of the two clutches drives an intermediate gear. The method includes the steps of determining a clutch torque and slip profile for the changeover of the clutches and determining a target engine speed profile. The torque transfer across each clutch is simultaneously controlled so that the torque output of the transmission will be linearly changed over from the first clutch to the second clutch to cause the engine to track the target engine speed profile. When the first clutch is slipping at a greater rate than the second clutch the method changes over the gears driven by the first clutch by disengaging the synchronizer of the initial gear and engaging the synchronizer of the final gear as the engine continues to tracks the target speed. The torque transfer across each clutch is simultaneously controlled so that the torque output of the transmission will be linearly changed back from the second clutch to the first clutch in an inversely proportional rate to continue to cause the engine to track the target engine speed profile.

Description

technical field [0001] The present invention generally relates to a method of controlling a dual-clutch transmission, and more particularly, the present invention relates to a method for automatically controlling positive torque shifting between two low gears by controlling the torque transmitted on the clutch of the dual-clutch transmission. Background technique [0002] In general, a ground vehicle requires a powertrain consisting of three basic components. These components include powerplants (such as internal combustion engines), transmissions and wheels. Transmission components are often simply referred to as "variator". The conversion takes place in the transmission according to the vehicle's tractive power, engine torque and speed. There are currently two types of transmissions widely used in conventional motor vehicles. The first and earliest type was the manually operated transmission. These transmissions include foot-operated actuating or actuating clutches for...

AI Technical Summary

Problems solved by technology

Since none of the current control methods provide a smooth and efficient transfer of torque from one clutch to the other in a single shift, so that the shift and subsequent change in engine speed is smooth enough to be unnoticeable by the driver, Therefore, the operation of shifting two lower gears causes a greater disruption

More specifically, the positive torque downshifts of existing control methods for two downshifts result in two distinct shifts, each of which causes an accompanying sudden change in vehicle speed

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