Control method for closing a clutch in an automatic manual transmission

A control method for closing a clutch in an automatic manual transmission during a gear shifting to pass from a current gear (A) to a successive gear (B);

• the automatic gear transmission comprising a gearbox, which is provided with at least one primary shaft and at least one secondary shaft connected to driving wheels, and at least one clutch, which is interposed between the primary shaft of the gearbox and a drive shaft of an engine;
• the control method comprising, when, during the closing of the clutch, the rotation speed (ωE) of an engine side of the clutch is close to the rotation speed (ωB) of a gearbox side of the clutch, the steps of:
• determining, by a transmission control unit, a speed difference (Δω) between the rotation speed (ωE) of the engine side of the clutch and the rotation speed (ωB) of the gearbox side of the clutch;
• determining, by the transmission control unit, an acceleration target (αTAR) according to the speed difference (Δω) so that the acceleration target (αTAR) progressively decreases as the speed difference (Δω) decreases;
• determining, by the transmission control unit, a first contribution (TCB-TAR1) of a target torque (TCB-TAR) to be transmitted through the clutch according to the acceleration target (αTAR) and using a closed-loop control;
• determining, by the transmission control unit, a second contribution (TCB-TAR2) of the target torque (TCB-TAR) to be transmitted through the clutch using an open-loop control;
• adding, by the transmission control unit, algebraically the first contribution (TCB-TAR1) of the target torque (TCB-TAR) to be transmitted through the clutch to the second contribution (TCB-TAR2) of the target torque (TCB-TAR) to be transmitted through the clutch (16B), in order to determine the target torque (TCB-TAR) to be transmitted through the clutch;
• and
• controlling a clutch actuator in association with the target torque (TCB-TAR).

A control method for closing a clutch in an automatic manual transmission during a gear shifting to pass from a current gear (A) to a successive gear (B);

• the automatic gear transmission comprising a gearbox, which is provided with at least one primary shaft and at least one secondary shaft connected to driving wheels, and at least one clutch, which is interposed between the primary shaft of the gearbox and a drive shaft of an engine;
• the control method comprising, when, during the closing of the clutch, the rotation speed (ωE) of an engine side of the clutch is close to the rotation speed (ωB) of a gearbox side of the clutch, the steps of:
• determining, by a transmission control unit, a speed difference (Δω) between the rotation speed (ωE) of the engine side of the clutch and the rotation speed (ωB) of the gearbox side of the clutch;
• assigning, by the transmission control unit and when the speed difference (Δω) is comprised between a first threshold and a second threshold lower than the first threshold, to an acceleration target (αTAR) a variable value depending on the speed difference (Δω) so that the acceleration target (αTAR) progressively decreases as the speed difference (Δω) decreases;
• assigning, by the transmission control unit and when the speed difference (Δω) is lower than the second threshold, to the acceleration target (αTAR) a constant and predetermined value;
• determining, by the transmission control unit, a target torque (TCB-TAR) to be transmitted through the clutch according to the acceleration target (αTAR);
• and
• controlling a clutch actuator in association with the target torque (TCB-TAR).