Method for monitoring a power supply of a control unit in a motor vehicle

• US 20040017205A1
• Filed: 09/02/2003
• Published: 01/29/2004
• Est. Priority Date: 06/02/2001
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schumacher, Hartmut, Sievers, Falko, Seibold, Jochen, Tschentscher, Harald, Nitsche, Gerald, Taufer, Peter
• Granted Patent: US 6,949,932 B2
• Time in Patent Office: Days
• US Class Current: 324/522
• CPC Class Codes: G01R 19/1659 to indicate that the value is within or outside a predetermined range of values (window) G01R19/16514, G01R19/16519, G01R19/16528 and G01R19/16533 take precedence
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass

Abstract

In a method of monitoring a voltage supply of a control unit in a motor vehicle, a supply module which provides the voltages is connected to the components of the control unit via a RESET line and the RESET line is tested every time the control unit is started or all monitoring limits of the supply module show no fault again after the faults of the monitored voltages have been filtered. This test occurs by forced periodic pulses which are generated on the basis of a shift in the limits of the monitoring bands of the supply voltages. The reference voltages VREGUL and VREF are kept independent of each other here in order to prevent system perturbations.

Claims

1. A method of monitoring a voltage supply of a control unit in a motor vehicle, the supply module (1) interrupting the functions of the control unit components via a RESET line (7) upon a fault being detected in the voltages generated by a supply module (1) in the control unit, the voltages being monitored for faults via bands (19, 20) and specified values (18), wherein a test of the RESET line (7) of the control unit is initiated, the supply module (1) then interrupting the functions of the components over the RESET line (7) for a predefined time period using periodic pulses, and a processor (2) counting the time between the interrupts to monitor the operation of the RESET line (7).

2. The method as recited in claim 1, wherein the limits (19, 20) of the bands are alternately shifted above and below the specified values (18, 23) during the test to force the interrupt.

3. The method as recited in claim 1 or 2, wherein the test is executed at the time of each startup of the control unit.

4. The method as recited in one of claims 1 through 3, wherein the components are stopped for each fault in the monitored voltages until all monitoring functions of the supply module (1) signal no fault in the voltages.

5. The method as recited in one of claims 1 through 4, wherein the supply module (1) provides two reference voltages that are independent of one another, the first reference voltage being used for regulating the voltages and the second reference voltage being used for monitoring the regulating voltage.

6. The method as recited in one of claims 1 through 5, wherein a warning is issued and/or functions of the control unit are blocked in the event of a failed test.

7. A control unit for carrying out the method as recited in one of claims 1 through 6, wherein the control unit has a supply module (1), which supplies the components (2 through 6, 50 through 52) of the control unit with the required voltages and is connected to the components (2 through 6, 50 through 52) via the RESET line (7), and a processor (2) of the control unit has means for performing the test of the RESET line (7).

8. The control unit as recited in claim 7, wherein the supply module (1) has means for providing at least two independent reference voltages (VREF, VREGUL).

9. The control unit as recited in claim 8, wherein the supply module (1) has at least two voltage sources (35, 36) that are independent of one another for providing the reference voltages (VREGUL, VREF).

10. The control unit as recited in claim 8, wherein the supply module (1) has one voltage source (39) and at least two impedance transformers (37, 38) for providing the reference voltages.

11. A supply module as recited in one of claims 7 through 11.