METHOD TO CONTROL THE EXECUTION OF A DOWNSHIFT WITH A RELEASED ACCELERATOR PEDAL IN A DRIVETRAIN PROVIDED WITH A DUAL-CLUTCH, SERVO-ASSISTED TRANSMISSION

A method to control the execution of a shift to a lower gear with a released accelerator pedal (22) in a drivetrain (6) provided with a dual-clutch, servo-assisted transmission (7); the following steps ate provided: opening, in a first instant (t1), an outgoing clutch (16A); closing, in the first instant (t1), an incoming clutch (16B); completing the opening of the outgoing clutch (16A) by means of a first linear ramp in a second instant; synchronizing, between the second instant and a third instant (t4), a rotation speed (ωE) of the internal combustion engine (4) with a rotation speed (ωB) of the incoming clutch (16B); closing of the incoming clutch (16B) by means of a second linear ramp starting from a fourth instant (t2), which is prior to or coincides with the second instant; completing the closing of the incoming clutch (16B) in a fifth instant (t3), which coincides with or is subsequent to the second instant; and activating the internal combustion engine (4) so as to generate a torque (TE) between the fourth instant (t2) and the third instant (t4).