Method of controlling a vehicle equipped with an internal combustion engine with a stop and start system

1. A method of controlling a vehicle equipped with an internal-combustion engine ( 1 ) with a “stop and start” system, wherein the internal-combustion engine ( 1 ) includes a driver-operated gear-selection lever and gearbox ( 17 ) and odd gears (ODD) are coupled to a same first primary shaft of the gearbox ( 17 ) and even gears (EVEN) are coupled to a same second primary shaft of the gearbox ( 17 ), the method comprising steps of:

providing, in a preliminary adjustment phase, a position sensor close to the gear-selection lever and being set-up to read the position of the gear-selection lever;

learning, during vehicle running, respective “duty cycle” values associated with the odd gears (ODD) and even gears (EVEN);

determining a “maximum duty cycle” value (ODD max ) of the “duty cycle” values that correspond to a condition of the odd gears (ODD);

determining a “minimum duty cycle” value (EVEN min ) of the “duty cycle” values that correspond to a condition of the even gears (EVEN);

determining a duty-cycle band to which a “neutral gear” condition (N) corresponds and that is included within a value range extremes of which are represented by the “minimum duty cycle” value (EVEN min ) of the “duty cycle” values that correspond to the “even gears (EVEN)” condition and “maximum duty cycle” value (ODD max ) of the “duty cycle” values that correspond to the “odd gears (ODD)” condition; and

controlling the “stop and start” system by at least one of controlling restarting of the internal-combustion engine ( 1 ) when a driver operates a clutch pedal and enabling switch-off of the internal-combustion engine ( 1 ) on a basis of the duty-cycle hand to which the “neutral gear” condition (N) corresponds.

2. A method according to claim 1 , wherein the method comprises further steps of:

determining, in a preliminary “set up and adjustment” phase, a first “duty-cycle threshold” value (Δ OS ) for the odd gears (ODD) and second “duty-cycle threshold” value (Δ ES ) for the even gears (EVEN);

calculating a first end value (ODD max +Δ OS ) for the odd gears (ODD) through an algebraic addition of the first “duty-cycle threshold” value (Δ OS ) for the odd gears (ODD) and “maximum duty cycle” value (ODD max ) of the “duty cycle” values that correspond to the “odd gears (ODD)” condition;

calculating a second end value (EVEN min −Δ ES ) for the even gears (EVEN) through an algebraic difference between the “minimum duty cycle” value (EVEN min ) of the “duty cycle” values that correspond to the “even gears (EVEN)” condition and second “duty-cycle threshold” value (Δ ES ) for the even gears (EVEN);

determining the duty-cycle band to which the “neutral gear” condition (N) corresponds and included within a value range extremes of which are represented by the first end value (ODD max +Δ OS ) for the odd gears (ODD) and second end value (EVEN min −Δ ES ) for the even gears (EVEN); and

controlling the “stop and start” system by the at least one of controlling restarting of the internal-combustion engine ( 1 ) when the driver operates the clutch pedal and enabling switch-off of the internal-combustion engine ( 1 ) on the basis of the duty-cycle band to which the “neutral gear” condition (N) corresponds.

3. A method according to claim 1 , wherein the method comprises further steps of:

determining, in a preliminary “set up and adjustment” phase, a first “duty-cycle tolerance” value (Δ OA ) for the odd gears (ODD) and second “duty-cycle tolerance” value (Δ EA ) for the even gears (EVEN);

calculating a further first end value (ODD max +Δ OA ) for the odd gears (ODD) through an algebraic addition of the first “duty-cycle tolerance” value (Δ OA ) for the odd gears (ODD) and “maximum duty cycle” value (ODD max ) of the “duty cycle” values that correspond to the “odd gears (ODD)” condition;

calculating a further second end value (EVEN min −Δ EA ) for the even gears (EVEN) through an algebraic difference between the “minimum duty cycle” value (EVEN min ) of the “duty cycle” values that correspond to the “even gears (EVEN)” condition and second “duty-cycle tolerance” value (Δ EA ) for the even gears (EVEN);

determining a further duty-cycle band on the basis of the further first end value (ODD max +Δ OA ) for the odd gears (ODD) and further second end value (EVEN min −Δ EA ) for the even gears (EVEN); and

controlling the restarting of the internal-combustion engine ( 1 ) when the driver operates the clutch pedal on the basis of die further duty-cycle band.

4. A control method according to claim 2 , wherein the first “duty-cycle tolerance” value (Δ OA ) for the odd gears (ODD) is different than the first “duty-cycle threshold” value (Δ OS ) for the odd gears (ODD) and the second “duty-cycle tolerance” value (Δ EA ) for the even gears (EVEN) is different than the second “duty-cycle threshold” value (Δ ES ) for the ever gears (EVEN).

5. A method according to claim 1 , wherein the method comprises further steps of:

storing the “duty cycle” values respectively associated with the odd gears (ODD) and even gears (EVEN) engaged during die vehicle running in an electronic-control unit ( 21 ); and

updating, during the normal vehicle running, the “duty cycle” values respectively associated with the odd gears (ODD) and even gears (EVEN) that are stored in the electronic-control unit ( 21 ).

6. A control method according to claim 5 , wherein the step of updating, during the normal vehicle running, the “duty cycle” values respectively associated with the odd gears (ODD) and even gears (EVEN) that are stored in the electronic-control unit ( 21 ) comprises sub-steps of:

verifying a plurality of reference conditions; and

enabling the continuous updating of the “duty cycle” values respectively associated with the odd gears (ODD) and even gears (EVEN) that are stored in the electronic-control unit ( 21 ) only in the case in which all of the reference conditions are successfully verified.

7. A control method according to claim 6 , wherein the method comprises further sub-steps of:

determining, in the preliminary “set up and adjustment” phase, an enabling time of predetermined duration; and

enabling the continuous updating of the “duty cycle” values respectively associated with the odd gears (ODD) and even gears (EVEN) that are stored in the electronic-control unit ( 21 ) only in the case in which all of the reference conditions are successfully verified for a period of time greater than the enabling time.

8. An electronic-control unit that is set to implement a method of controlling a vehicle equipped with an internal-combustion engine ( 1 ) with a “stop and start” system, wherein the internal-combustion engine ( 1 ) includes a driver-operated gear-selection lever, gearbox ( 17 ) and odd gears (ODD) are coupled to a same first primary shaft of the gearbox ( 17 ) and even gears (EVEN) are coupled to a same second primary shaft of the gearbox ( 17 ), and the method includes steps of:

providing, in a preliminary adjustment phase, a position sensor close to the gear-selection lever and being set-up to read the position of the gear-selection lever;

learning, during vehicle running, respective “duty cycle” values associated with the odd gears (ODD) and even gears (EVEN);

determining a “maximum duty cycle” value (ODD max ) of the “duty cycle” values that correspond to a condition of the odd gears (ODD);

determining a “minimum duty cycle” value (EVEN min ) of the “duty cycle” values that correspond to a condition of the even gears (EVEN);

determining a duty-cycle hand to which a “neutral gear” condition (N) corresponds and that is included within a value range extremes of which are represented by the “minimum duty cycle” value (EVEN min ) of the “duty cycle” values that correspond to the “even gears (EVEN)” condition and “maximum duty cycle” value (ODD max ) of the “duty cycle” values that correspond to the “odd gears (ODD)” condition; and

controlling the “stop and start” system by at least one of controlling restarting of the internal-combustion engine ( 1 ) when a driver operates a clutch pedal and enabling switch-off of the internal-combustion engine ( 1 ) on a basis of the duty-cycle hand to winch the “neutral gear” condition (N) corresponds.