Method for managing the "stop-and-start" mode in a motor vehicle equipped with an internal combustion engine

• US 20060150937A1
• Filed: 12/13/2005
• Published: 07/13/2006
• Est. Priority Date: 12/23/2004
• Status: Active Grant

• Current Assignee: Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.)
• Original Assignee: Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.)
• Inventors: Lupo, Savino Luigi, Pennese, Michele
• Granted Patent: US 7,347,175 B2
• Time in Patent Office: Days
• US Class Current: 123/179.400
• CPC Class Codes: F01P 7/048 using electrical drives
• CPC Class Codes: F02D 2250/31 Control of the fuel pressure
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02D 41/1494 Control of sensor heater
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/222 relating to the failure of sensors or parameter detection devices
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0818 Conditions for starting or stopping the engine or for deactivating the idle-start-stop mode
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]
• CPC Class Codes: F02N 2200/0809 Electrical loads
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for managing the “stop-and-start” mode in a motor vehicle equipped with an internal combustion engine; the method provides for the “stop-and-start” mode to be enabled or disabled as a function of a state of charge (SOC) of a battery of the motor vehicle, as a function of a state of motion of a driveshaft of the internal combustion engine and as a function of the electric power consumed overall by the electrical consumers of the motor vehicle.

Claims

1. Method for managing the “

stop-and-start”

mode in a motor vehicle (27) equipped with an internal combustion engine (1);

the method comprises the phases of;

determining a state of charge (SOC) of a battery (20) of the motor vehicle (27);

determining a state of motion of a driveshaft (15) of the internal combustion engine (1); and

determining the electric power consumed overall by the electrical consumers of the motor vehicle (27);

the method is characterised by the fact that it comprises the further phases of;

enabling or disabling the “

stop-and-start”

mode as a function of the state of charge (SOC) of the main battery (20), as a function of the state of motion of the driveshaft (15) of the engine (1), and as a function of the electric power consumed overall by the electrical consumers of the motor vehicle (27); and

determining the state of motion of the driveshaft (15) by selecting one of the following alternatives;

the driveshaft (15) is stationary, the driveshaft (15) is in the starting phase, the driveshaft (15) is in rotation but is not capable of being self-sustaining, the driveshaft (15) is in rotation and capable of being self-sustaining, and the driveshaft (15) is in the stopping phase.

2. Method according to claim 1, wherein, if the driveshaft (15) is stationary or in the stopping phase, then the pressure value in a fuel injection circuit is periodically checked and, on the basis of the pressure value in the fuel injection circuit, signals are given to switch a fuel pump (22) on and off.

3. Method according to claim 2, wherein the fuel pump (22) is switched off if the pressure value in the injection circuit is greater than a first predetermined threshold value and the fuel pump (22) is switched on if the pressure value in the injection circuit is below a second predetermined threshold value.

4. Method according to claim 1, wherein, if the driveshaft (15) is stationary or in the stopping phase, then a heater (24) for the mixture concentration gauge (11) in an exhaust system (10) is operated at low power in such a manner as to ensure a predetermined minimum temperature.

5. Method according to claim 1, wherein, if the driveshaft (15) is stationary or in the stopping phase, then an electric fan (25) coupled to a liquid coolant radiator (26) is operated at low power in such a manner as to ensure a predetermined maximum temperature.

6. Method according to claim 1, wherein, if the driveshaft (15) is in the starting phase, then a signal is given to switch on a fuel pump (22), an electric fan (25) coupled to a liquid coolant radiator (26) is operated at low power in such a manner as to ensure a predetermined maximum temperature, and a heater (24) for the mixture concentration gauge (11) in an exhaust system (10) is operated at nominal power.

7. Method according to claim 6, wherein, if the driveshaft (15) is in the starting phase, then any electrical consumers that are not essential to safety or to the running of the motor vehicle (27) are operated at reduced power or are switched off.

8. Method according to claim 1, wherein, if the driveshaft (15) is in rotation and capable of being self-sustaining, then a fuel pump (22) is operated at nominal power, an electric fan (25) coupled to a liquid coolant radiator (26) is operated at nominal power, and a heater (24) for the mixture concentration gauge (11) in an exhaust system (10) is operated at nominal power.

9. Method according to claim 1, wherein, if the driveshaft (15) is in rotation and capable of being self-sustaining and the state of charge (SOC) of the battery (20) of the motor vehicle (27) is between a lower battery threshold value and an upper battery threshold value, then “

stop-and-start”

mode is enabled, an electrical energy generator (19) is controlled in order to perform normal recharging of the battery (20), and regenerative braking mode, if present, is enabled.

10. Method according to claim 9, wherein the state of charge (SOC) of the battery (20) of the motor vehicle (27) corresponding to the upper battery threshold value is less than the maximum possible value corresponding to the fully charged battery (20).

11. Method according to claim 1, wherein, if the driveshaft (15) is in rotation and capable of being self-sustaining and the state of charge (SOC) of the battery (20) of the motor vehicle (27) is greater than an upper battery threshold value, then “

stop-and-start”

mode is enabled, an electrical energy generator (19) is controlled in order to suspend recharging of the battery (20), and regenerative braking mode, if present, is disabled.

12. Method according to claim 11, wherein the state of charge (SOC) of the battery (20) of the motor vehicle (27) corresponding to the upper battery threshold value is less than the maximum possible value corresponding to a fully charged battery (20).

13. Method according to claim 1, wherein, if the driveshaft (15) is in rotation and capable of being self-sustaining and the state of charge (SOC) of the battery (20) of the motor vehicle (27) is below a lower battery threshold value, then “

stop-and-start”

mode is disabled, an electrical energy generator (19) is controlled in order to perform maximum possible recharging of the battery (20) and regenerative braking mode, if present, is enabled.

14. Method according to claim 13, wherein, if the driveshaft (15) is in rotation and capable of being self-sustaining and the state of charge (SOC) of the battery (20) of the motor vehicle (27) is below a lower battery threshold value, then any electrical consumers that are not essential to safety or to the running of the motor vehicle (27) are operated at reduced power or are switched off.

15. Method according to claim 1, wherein the state of health (SOH) of the main battery (20) is determined;

“

stop-and-start”

mode is disabled irrespective of other factors if the state of health (SOH) of the battery (20) is below a predetermined caution threshold value.

16. Method according to claim 15, wherein, if the state of health (SOH) of the battery (20) is below a predetermined alarm threshold value, then the electrical supply to any electrical consumers that are not essential to safety or to the running of the motor vehicle (27) is shut off.

17. Method according to claim 15, wherein the state of health (SOH) of the battery (20) is stated as a percentage.

18. Method according to claim 1, wherein, on every start, the value of a parameter indicating the quality of start is determined;

“

stop-and-start”

mode is disabled irrespective of other factors if the mean of recent values of the parameter indicating the quality of start is below a predetermined threshold value.

19. Method according to claim 1, wherein “

stop-and-start”

mode is disabled irrespective of other factors if a maximum defrosting function of a windscreen (30) of the motor vehicle (27) is activated.

20. Method according to claim 1, wherein “

stop-and-start”

mode is disabled irrespective of other factors if a demisting function of a rear window (31) of the motor vehicle (27) is activated.

21. Method according to claim 1, wherein “

stop-and-start”

mode is disabled irrespective of other factors if a malfunction of the mixture concentration gauge (11) in an exhaust system (10) is signalled.

22. Method according to claim 1, wherein “

stop-and-start”

mode is disabled irrespective of other factors if a condition of incomplete adjustment of mixture concentration is signalled.

23. Method according to claim 1, wherein “

stop-and-start”

mode is disabled irrespective of other factors if faults in the sensors and/or actuators of the internal combustion engine (1) are signalled that may have a negative impact on the control of pollutant emissions during starting of the engine (1).

24. Method according to claim 23, wherein “

stop-and-start”

mode is disabled irrespective of other factors if a fault in a phase sensor of the internal combustion engine (1) is signalled.

25. Method according to claim 23, wherein “

stop-and-start”

mode is disabled irrespective of other factors if a fault in the injectors (12) of the internal combustion engine (1) is signalled.

26. Method according to claim 23, wherein “

stop-and-start”

mode is disabled irrespective of other factors if a fault in the ignition coils of the internal combustion engine (1) is signalled.