Method and device for determining the starting capability of a vehicle

• US 7,026,787 B2
• Filed: 03/05/2002
• Issued: 04/11/2006
• Est. Priority Date: 05/26/2001
• Status: Expired due to Term

• Current Assignee: Chemtron Research LLC (Intellectual Ventures LLC)
• Original Assignee: DaimlerChrysler AG (Mercedes-Benz Group AG)
• Inventors: Zimmermann, Roger, Mäckel, Rainer
• Primary Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US10/478,993
• Publication Number:
  US 20040239332A1
• Time in Patent Office: 1,498 Days
• Field of Search: 320/104, 320/132, 320/149, 320150-153, 324/427, 324/429, 324/430, 324/431, 324/327
• US Class Current: 320/104
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: F02N 11/10 Safety devices F02N11/08 takes precedence
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]

Abstract

A method for determining the ability of a vehicle to start, in order to detect the operational capability of a battery, in particular of a vehicle battery, in a particularly simple and reliable way. Current values and voltage values of the battery are sensed during a predefined time window, in particular while the vehicle is being started. An internal resistance of the battery is determined by reference to the current values and the voltage values by means of linear regression, and a reference resistance value for the starting behavior of the vehicle is determined by reference to a maximum value for the current and a minimum value for the voltage which are sensed within the predefined time window. A value which represents the ability to start is determined by reference to a comparison between the internal resistance and the reference resistance value.

Claims

1. A method for determining the ability of a vehicle to start, comprising the steps of:

sensing current values (I) and voltage values (U) of a battery during a predefined time window,

determining an internal resistance (R_I) of the battery by reference to the current values (I) and the voltage values (U) by means of linear regression,

determining a reference resistance value (R_S) for the starting behavior of the vehicle by reference to a maximum value (I_MAX) for the current (I) and a minimum value (U_MIN) for the voltage (U) which are sensed within the predefined time window and

determining a value which represents the ability to start by reference to a comparison between the internal resistance (R_I) and the reference resistance value (R_S).

2. The method as claimed in claim 1, wherein a value for the internal resistance (R_I) of the battery is monitored to determine whether it drops below the reference resistance value (R_S).

3. The method as claimed in claim 2, wherein as a function of an instantaneously determined temperature (T1) of at least one of the battery and the starter circuit, the value which represents the ability to start is determined for another temperature (T2, T3) by reference to the value, which represents this temperature (T1), for the internal resistance (R_I) or reference resistance value (R_S).

4. The method as claimed in claim 1, wherein a signal message (M) is output in when the value for the internal resistance (R_I) of the battery is equal to or greater than the reference resistance value (R_S).

5. The method according to claim 4, wherein a temperature (T) of at least one of the battery and a starter circuit of the vehicle is determined.

6. The method according to claim 1, wherein a temperature (T) of at least one of the battery and a starter circuit of the vehicle is determined.

7. The method as claimed in claim 1, wherein as a function of an instantaneously determined temperature (T1) of at least one of the battery and the starter circuit, the value which represents the ability to start is determined for another temperature (T2, T3) by reference to the value, which represents this temperature (T1), for the internal resistance (R_I) or reference resistance value (R_S).

8. The method as claimed in claim 1, wherein charge start (L) of the battery is monitored and is linked to the internal resistance (R_I) of the battery in such a way that, when the value drops below a limiting value (G_U) for the internal resistance (R_I) for a given charge state (L), the battery is disconnected from the on-board electrical system.

9. A device for determining the ability of a vehicle to start, said device comprising:

a current sensor for sensing current values (I) and a voltage sensor for sensing voltage values (U) of a battery during a predefined time window;

an evaluation unit for determining an internal resistance (R_I) of the battery by reference to the current values (I) and the voltage values (U) by means of linear regression, and for determining a reference resistance value (R_S) for the starting behavior of the vehicle by reference to a maximum value (I_MAX) for the current (I) and a minimum value (U_MIN) for the voltage (U) which are sensed within the predefined time window, whereby it is possible to determine a value which represents the ability to start by reference to a comparison between the internal resistance (R_I) and the reference resistance value (R_S).

16. The device according to claim 9, including means for monitoring a value for the internal resistances of the battery to determine whether said internally resistance of a battery drops below the reference resistance value.

17. The device claimed at claim 9, further including a means for outputting a signal message when the value for the internal resistances of the battery is equal to or greater than the reference resistances value.

18. The device claimed at claim 9, further including a sensor for determining a temperature of at least one of the battery and a starter circuit of the vehicle.

10. A method for determining the starting status of an automobile, comprising the steps of:

measuring current and voltage values of a battery;

determining an internal resistance of the battery as a function of said current and voltage values;

providing a reference resistance value as a function of a maximum current value and a minimum voltage value during a predetermined interval;

comparing said internal resistance value with said reference resistance value.

11. The method as claimed in claim 10, wherein a value for the internal resistance (R_I) of the battery is monitored to determine whether it drops below the reference resistance value (R_S).

12. The method as claimed in claim 10, wherein, a signal message (M) is output in when the value for the internal resistance (R_I) of the battery is equal to or greater than the reference resistance value (R_S).

13. The method according to claim 10, wherein a temperature (T) of at least one of the battery and a starter circuit of the vehicle is determined.

14. The method as claimed in claim 10, wherein, as a function of an instantaneously determined temperature (T1) of at least one of the battery and the starter circuit, the value which represents the ability to start is determined for another temperature (T2, T3) by reference to the value, which represents this temperature (T1), for the internal resistance (R_I) or reference resistance value (R_S).

15. The method as claimed in claim 10, wherein charge start (L) of the battery is monitored and is linked to the internal resistance (R_I) of the battery in such a way that, when the value drops below a limiting value (G_U) for the internal resistance (R_I) for a given charge state (L), the battery is disconnected from the on-board electrical system.