Method to control execution of shift to higher gear with released accelerator pedal

Abstract

A method to control the execution of a shift to a higher gear with a released accelerator pedal (22) in a drivetrain (6) provided with a dual-clutch, servo-assisted transmission (7), comprising the steps of: opening, in a first instant (t1), an outgoing clutch (16A); closing, in the first instant (t1), an incoming clutch (16B); synchronizing, between a second instant (t2) and a third instant (t4),a rotation speed ([omega]E) of the internal combustion engine (4) with a rotation speed ([omega]B) of the incoming clutch (16B), namely with the rotation speed ([omega]B) imposed by the gear ratio ofthe following gear (B); completely opening, in the third instant (t4), the outgoing clutch (16A); completely closing, in the third instant (t4), the incoming clutch (16A); keeping the torque (TA) transmitted by the outgoing clutch (16A) constant between the second instant (t2) and a fourth instant (t3); and keeping the torque (TB) transmitted by the incoming clutch (16B) constant between the second instant (t2) and the fourth instant (t3).

Description

[0001] Cross References to Related Applications [0002] This patent application claims priority from Italian Patent Application No. 102019000017543, filed September 30, 2019, the entire disclosure of which is hereby incorporated by reference. technical field [0003] The present invention relates to a method of controlling a shift to a higher gear (i.e. the subsequent or incoming gear is higher than the previous or shifting of the left gear). Background technique [0004] A powertrain with a dual-clutch servo-assisted gearbox includes: a pair of main shafts coaxial with each other, independent of each other and inserted into each other; two coaxial clutches each designed to connect the corresponding main shaft to a drive shaft of the internal combustion engine; and at least one layshaft which transmits motion to the drive wheels and which may be coupled to the main shaft by respective gear trains each defining a gear. [0005] During a gear change, the current gear couple...

AI Technical Summary

Problems solved by technology

[0007] From a control point of view, the mode of execution of this shift to a higher gear with the release of the accelerator pedal is crucial, because with both clutches kept open, the step of regulating the speed of the internal combustion engine is only fully Assigned to the internal combustion engine; it often happens that, in order to then synchronize with a sudden increase, the engine speed is reduced too much to first produce a forward pull, and then the engine speed tries to increase again to reach the speed of the entering clutch The moment of rev produces a strong rearward pull (thus, the overall feeling perceived by the driver is not very comfortable)

Images