Method and apparatus for identification of an external power supply in a motor vehicle

• US 6,662,123 B2
• Filed: 03/09/2001
• Issued: 12/09/2003
• Est. Priority Date: 03/09/2000
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH, Daimler Chrysler Company LLC (Stellantis NV)
• Original Assignee: Robert Bosch GmbH, Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Kneifel, Marcus, Maeckel, Rainer
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): Kim, Paul L.
• Application Number:
  US09/801,832
• Publication Number:
  US 20010035757A1
• Time in Patent Office: 1,005 Days
• Field of Search: 702/63, 702/64, 324/426, 324/430, 701/29, 701/34, 701/35, 701/36, 307/10.3, 307/9.1, 307/10.7, 307/10.1, 429/90
• US Class Current: 702/60
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits

Abstract

A device for identification of an external start is fitted in a vehicle which has an electrical on-board power supply system (14) fed with an on-board power supply system voltage of about 12.5 V via a vehicle battery (10). A negative pole (11) of the battery (10) is connected to a vehicle earth (15). A monitoring unit (13) is arranged between a positive pole (12) of the battery (10) and the on-board power supply system (14). A conventional voltage sensor (20) for detection of the on-board power supply system voltage, a similarly conventional current sensor (21) for detection of the current flowing out of the battery, and a conventional temperature sensor (22) for detection of the operating temperature of the battery (10) are provided in the monitoring unit (13). The main measurement variable is the on-board power supply system voltage; the battery current and the battery temperature represent auxiliary measurement variables in a monitoring algorithm. Furthermore, the monitoring unit (13) contains a microcontroller (23), which can identify a change in the on-board power supply system load via a CAN bus (25). As is indicated by the dashed line (26), the on-board power supply system load can also be detected directly via a controllable switch (24).

Claims

1. A device for detecting presence of an external power supply connected to a motor vehicle which has an electrical on-board power supply system and a battery, for providing an on-board power supply system voltage, said device comprising:

a monitoring unit arranged between the battery and the on-board power supply system;

said monitoring unit having at least one sensor for detection of an on-board power supply system voltage; and

said monitoring unit also having a computer for automatically identifying changes in the on-board power supply system voltage and determining presence of an external power supply connected to the vehicle, based on said changes.

2. The device according to claim 1, wherein the monitoring unit has or interacts with at least one further sensor for detecting an on-board power supply current flowing out of the battery or into the on-board power supply system.

3. The device according to claim 2, wherein the monitoring unit includes means for identifying changes in the on-board power supply system load, based on the on-board power supply system voltage and the on-board power supply system current.

4. The device according to claim 1, wherein the monitoring unit has or interacts with a sensor for detecting an operating temperature of the battery.

5. The device according to claim 3, wherein:

the computer comprises a microcontroller; and

the computer automatically determines changes in electrical on-board power supply system variables.

6. The device according to claim 5, further comprising a controllable switch for actively changing the on-board power supply system load, which switch interacts with the microcontroller.

7. The device according to claim 5, wherein:

the microcontroller is connected to a CAN bus for data transmission in the vehicle; and

any change in the on-board power supply system load is identified by means of data provided via the CAN bus.

8. The device according to claim 1, further comprising a timer for detection of time duration of any drop in voltage in the on-board power supply system voltage.

9. The device according to claim 1, wherein said computer comprises:

means for storage of a value of at least one of the on-board power supply system voltage and the on-board power supply system load; and

means for comparing the stored value with one of a sensed present on-board power supply system voltage or on-board power supply system load, and for determining presence of said external power supply based on a result of said comparison.

10. A method of operating a device for detecting presence of an external power supply connected to a motor vehicle which has an engine with an electrical voltage generator operated by the engine and an electrical on-board power supply system with a battery, for providing an on-board power supply system voltage, said device comprising a monitoring unit arranged between the battery and the on-board power supply system;

said monitoring unit having at least one sensor for detection of an on-board power supply system voltage; and

said monitoring unit also having a computer for automatically identifying changes in the on-board power supply system voltage and determining presence of an external power supply connected to the vehicle;

said method comprising;

monitoring at least one of electrical on-board power supply system variables and a state of the monitoring unit during a starting phase of the monitoring unit;

monitoring at least one of electrical on-board power supply system variables before starting the engine;

monitoring of at least one of the battery state variables during an engine starting phase; and

said computer detecting connection of an external power supply based on an analysis of said monitored variables.

11. The method according to claim 10, further comprising:

monitoring at least one battery state variable after an engine start, until the vehicle starts to be driven.

12. The method according to claim 10, wherein:

the first monitoring step is performed only once during starting of the monitoring unit; and

the second and third monitoring steps are performed repeatedly until a defined final state is reached.

13. The method according to claim 10, wherein:

the first monitoring step checks whether the monitoring unit is activated from a sleep mode or from a power-on-reset mode; and

in the event of a power-on-reset mode, a further check is made whether a presettable minimum voltage drop duration has been exceeded.

14. The method according to claim 10, wherein:

before the monitoring unit enters a sleep mode, one of a most recently measured on-board power supply system voltage and an on-board power supply system voltage detected cyclically by means of regular waking up from the sleep mode, is stored; and

a regularly detected present on-board power supply system voltage is compared with the stored value.

15. The method according to claim 14, wherein the on-board power supply system load is also detected and is compared to a corresponding value.

16. The method according to claim 10, wherein:

the second monitoring step checks whether the on-board power supply system voltage, when the engine is not running, is greater than a first threshold value which is between a battery normal voltage and a generator normal voltage; and

if so, a further check is made whether an engine start will be carried out within a first time window which can be predetermined.

17. The method according to claim 16, wherein, if no engine start takes place within a first time window, a further check is made to determine whether the on-board power supply system voltage has fallen again, without the on-board power supply system load having changed.

18. The method according to claim 16, wherein if the on-board power supply system voltage does not exceed the first threshold value, another check is carried out to determine whether the on-board power supply system voltage, when the engine is not running, has increased within a second predeterminable time window which is between approximately five and ten seconds.

19. The method according to claim 18, wherein a further check is made to determine whether the on-board power supply system voltage is greater than a second threshold value.

20. The method according to claim 10, wherein the second monitoring step checks whether the on-board power supply system voltage is greater than a third threshold value, with the on-board power supply system load remaining constant and without the generator supplying any power.

21. The method according to claim 10, wherein:

in the third monitoring step, electrical internal resistance of the battery is detected and stored during an engine start that has been carried out; and

a check is then made to determine whether a presently measured value of the internal resistance is less than the stored value.

22. The method according to claim 10, wherein:

in the third monitoring step, operating temperature of the battery is also detected; and

a comparison is made to determine whether the operating temperature is greater than a specified value.

23. The method according to claim 22, wherein at least one of a detected internal resistance and detected operating temperature of the battery is stored in the event of a first starting attempt.

24. The method according to claim 23, wherein battery parameters of a most recent starting attempt are used as a reference for comparison.

25. The method according to claim 10, wherein a switch signal from one of a vehicle trunk lid and a hood of the vehicle is evaluated to establish whether they are open.

26. The method for identification of an externally caused push against a motor vehicle, as an additional monitoring step in a method according to claim 10, wherein

at least one wheel rotation speed and engine rotation speed of the motor vehicle are monitored;

and

if a wheel rotation speed value >

0 is detected and an engine rotation speed value=0 is detected at the same time, it is concluded that the motor vehicle is being pushed by an external source, in particular that the motor vehicle is being towed.