Diagnostic device for a multi-voltage vehicle electrical system, a multi-voltage vehicle electrical system, and a method for operating a multi-voltage vehicle electrical system

• US 9,310,411 B2
• Filed: 09/04/2012
• Issued: 04/12/2016
• Est. Priority Date: 10/07/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Seg Automotive Germany GMBH
• Original Assignee: Robert Bosch GmbH
• Inventors: Mehringer, Paul, Merkle, Michael, Eschenhagen, Marc
• Primary Examiner(s): Edwards, Jerrah
• Assistant Examiner(s): WEBER, TAMARA L
• Application Number:
  US14/349,299
• Publication Number:
  US 20140350781A1
• Time in Patent Office: 1,316 Days
• US Class Current: 1/1
• CPC Class Codes: B60L 1/00 Supplying electric power to auxiliary equipment of vehicles circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: B60R 16/0232 for measuring vehicle parameters and indicating critical, abnormal or dangerous conditions
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: G01R 19/14 Indicating direction of current; Indicating polarity of voltage
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/50 Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections testing of sparking plugs H01T13/58
• CPC Class Codes: G06N 20/00 Machine learning

Abstract

A diagnostic device is provided for a multi-voltage electrical system of a motor vehicle which has a first subnetwork acted on by a first voltage and a second subnetwork acted on by a second voltage, the first voltage being higher than the second voltage, and the first and the second subnetwork having a shared ground connection. The diagnostic device includes a second ground connection, a measuring unit configured to measure a current flow via the second ground connection, and a diagnostic unit configured to diagnose a disturbance in the shared ground connection and/or in the second ground connection on the basis of the measured current flow via the second ground connection as a function of at least one operating state of the vehicle electrical system.

Claims

1. A diagnostic device for a multi-voltage electrical system of a motor vehicle having an internal combustion engine, the multi-voltage vehicle electrical system including a first subnetwork acted on by a first voltage and at least one other subnetwork acted on by at least one other voltage, the first voltage being higher than the at least one other voltage, and the first subnetwork and the at least one other subnetwork having a shared first ground connection, the diagnostic device comprising:

at least one second ground connection; and

processing circuitry that is programmed to perform a diagnostic function, wherein;

the diagnostic function includes diagnosing a disturbance in at least one of the shared first ground connection and the at least one second ground connection based on (a) an obtained measurement of a current flow via the at least one second ground connection, and (b) at least one operating state of the multi-voltage vehicle electrical system; and

the at least one second ground connection and the shared first ground connection are connected in parallel such that currents flowing via a starter situated in the second subnetwork and a generator situated in the first subnetwork flow via the shared first ground connection and the at least one second ground connection when the internal combustion engine is started under the conditions of the shared first ground connection being undisrupted and the at least one second ground connection being undisrupted.

2. The diagnostic device as recited in claim 1, wherein the at least one second ground connection and the shared first ground connection are connected in parallel in such a way that during a cold start with the aid of the starter, a larger portion of the flowing currents flows via the shared first ground connection and the remaining, smaller portion of the flowing currents flows via the at least one second ground connection.

3. The diagnostic device as recited in claim 2, wherein:

the generator is a starter generator; and

the at least one second ground connection and the shared first ground connection are connected in parallel in such a way that during a warm start with the aid of the starter generator, a larger portion of the flowing currents flows via the at least one second ground connection and the remaining, smaller portion of the flowing currents flows via the shared first ground connection.

4. The diagnostic device as recited in claim 3, wherein the shared first ground connection is provided on the internal combustion engine of the motor vehicle, and wherein at least one component of the first subnetwork and at least one component of the at least one other subnetwork are connected to the shared first ground connection.

5. The diagnostic device as recited in claim 3, wherein the at least second ground connection is a ground connection of the generator which is conductively connected to the internal combustion engine.

6. The diagnostic device as recited in claim 3, wherein the first voltage is 48 V and the at least one other voltage is one of 12 V or 14 V.

7. The diagnostic device as recited in claim 3, wherein the first subnetwork is acted on by the first voltage with the aid of at least one voltage source, and the at least one other subnetwork is acted on by the at least one other voltage with the aid of at least one other voltage source.

8. A multi-voltage electrical system for a motor vehicle, comprising:

a first subnetwork acted on by a first voltage;

at least one other subnetwork acted on by at least one other voltage, wherein the first voltage is higher than the at least one other voltage, and the first subnetwork and the at least one other subnetwork have a shared first ground connection; and

a diagnostic device including;

at least one second ground connection; and

processing circuitry that is programmed to perform a diagnostic function, wherein;

the diagnostic function includes diagnosing a disturbance in at least one of the shared first ground connection and the at least one second ground connection based on (a) an obtained measurement of a current flow via the at least one second ground connection, and (b) at least one operating state of the multi-voltage vehicle electrical system; and

the at least one second ground connection and the shared first ground connection are connected in parallel such that currents flowing via a starter situated in the second subnetwork and a generator situated in the first subnetwork flow via the shared first ground connection and the at least one second ground connection when the internal combustion engine is started under the conditions of the shared first ground connection being undisrupted and the at least one second ground connection being undisrupted.

9. A method for operating a diagnostic device for a multi-voltage electrical system of a motor vehicle having an internal combustion engine, the multi-voltage vehicle electrical system including a first subnetwork acted on by a first voltage and at least one other subnetwork acted on by at least one other voltage, the first voltage being higher than the at least one other voltage, and the first subnetwork and the at least one other subnetwork having a shared first ground connection, the diagnostic device including at least one second ground connection, and processing circuitry programmed to perform a diagnostic function, the method comprising:

obtaining, by the processing circuitry, a measurement of a current flow via the at least one second ground connection; and

diagnosing, by the processing circuitry performing the diagnostic function, a disturbance in at least one of the shared first ground connection and the at least one second ground connection on the basis of the obtained measurement and as a function of whether the internal combustion engine is started in one of a cold start condition or a warm start condition.