Managing Steering with Short From Battery to Ground

• US 20140350794A1
• Filed: 05/23/2013
• Published: 11/27/2014
• Est. Priority Date: 05/23/2013
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Bickel, Thomas J., Wilke, Amanda J., Stahl, Wendell D., Genseal, Andrew G., Uddin, Md Nasir, Richards, Dane S., Nelson, Jennie L.
• Granted Patent: US 9,139,223 B2
• Time in Patent Office: Days
• US Class Current: 701/42
• CPC Class Codes: B62D 5/04 electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
• CPC Class Codes: B62D 5/0481 monitoring the steering system, e.g. failures
• CPC Class Codes: B62D 6/00 Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00
• CPC Class Codes: H02H 3/16 responsive to fault current to earth, frame or mass with balanced or differential arrangement H02H3/26 ; monitoring earth connection H02H5/105

Abstract

A redundancy system for a steering system having a primary controller and a primary power source is provided. The redundancy system may include a secondary controller coupled to a secondary power source and configured to manage control of the steering system, and an interface circuit disposed between at least a first node and a second node. The first node may be in electrical communication with the primary power source, and the second node may be in electrical communication with the secondary power source. The interface circuit may be configured to selectively engage a self-test of the primary power source and the secondary power source, isolate a short at the first node from the secondary power source, and isolate a short at the second node from the primary power source.

Claims

1. A method of providing redundant control of a steering system using one of a first controller and a second controller, the method comprising the steps of:

providing an interface circuit between at least a first node and a second node of the steering system, the first node being electrically disposed between a primary power source and the first controller, the second node being electrically disposed between a secondary power source and the second controller;

automatically engaging a self-test of the primary power source and the secondary power source upon machine startup;

in response to a short at the first node, engaging the interface circuit to isolate the short from the secondary power source, and engage the second controller to operate the steering system; and

in response to a short at the second node, engaging the interface circuit to isolate the short from the primary power source, and enable the first controller to operate the steering system.

2. The method of claim 1, wherein the interface circuit includes one or more self-test elements that are electronically actuatable for engaging the self-test.

3. The method of claim 2, wherein the self-test element includes one or more of a relay and a switch that is electronically engageable between an opened state and a closed state, the self-test element being automatically engaged into the opened state upon machine startup.

4. The method of claim 1, wherein the interface circuit includes at least a fusible link configured to prevent dissipation of current from the primary power source through a short at the second node, and enable the first controller to maintain operation of the steering system.

5. The method of claim 1, wherein the interface circuit includes at least a blocking device configured to prevent dissipation of current from the secondary power source through a short at the first node, and enable the second controller to operate the steering system.

6. A redundancy system for a steering system having a primary controller and a primary power source, the redundancy system comprising:

a secondary controller coupled to a secondary power source and configured to manage control of the steering system; and

an interface circuit disposed between at least a first node and a second node, the first node being in electrical communication with the primary power source, the second node being in electrical communication with the secondary power source, the interface circuit being configured to selectively engage a self-test of the primary power source and the secondary power source, isolate a short at the first node from the secondary power source, and isolate a short at the second node from the primary power source.

7. The redundancy system of claim 6, wherein the self-test element employs one or more of a relay and a switch, and is electronically engageable between an opened state and a closed state.

8. The redundancy system of claim 6, wherein the self-test element is automatically engaged into an opened state upon machine startup to diagnose any deficiencies in the primary power source and the secondary power source.

9. The redundancy system of claim 6, wherein each of the primary power source and the secondary power source comprises one or more batteries capable of supplying a direct current (DC) to a common bus extending between the first node and the second node.

10. The redundancy system of claim 6, wherein the interface circuit includes at least a fusible link employing one or more of a fuse and a breaker configured to prevent dissipation of current from the primary power source through a short at the second node.

11. The redundancy system of claim 6, wherein the interface circuit includes at least a blocking device employing one or more of a fuse, a diode, a transistor, a switch, and a breaker configured to prevent dissipation of current from the secondary power source through a short at the first node.

12. The redundancy system of claim 6, wherein a first protective element is disposed between the primary power source and the primary controller, a second protective element is disposed between the secondary power source and the secondary controller, each of the first protective element and the second protective element having a current limit approximate to that of a fusible link of the interface circuit disposed between the first node and the second node.

13. A control system, comprising:

a primary power source in communication with a common bus associated with the control system;

a secondary power source in selective communication with the common bus;

a first controller in communication with a first node of the common bus configured to manage control of a steering system;

a second controller in communication with a second node of the common bus configured to manage control of the steering system; and

an interface circuit disposed between the first node and the second node, the interface circuit having a blocking device configured to isolate a short at the first node from the secondary power source, a fusible link configured to isolate a short at the second node from the primary power source, and a self-test element configured to selectively engage a self-test of the primary power source and the secondary power source.

14. The control system of claim 13, wherein the self-test element employs one or more of a relay and a switch, and is electronically engageable between an opened state and a closed state.

15. The control system of claim 13, wherein the self-test element is automatically engaged into an opened state upon machine startup to diagnose any deficiencies in the primary power source and the secondary power source.

16. The control system of claim 13, wherein each of the primary power source and the secondary power source comprises one or more batteries supplying a direct current (DC) to the common bus, the first node being in communication with a positive terminal of the batteries of the primary power source, and the second node being in communication with a positive terminal of the batteries of the secondary power source.

17. The control system of claim 13, wherein the fusible link employs one or more of a fuse and a breaker and is configured to prevent dissipation of current from the primary power source through a short at the second node.

18. The control system of claim 13, wherein the blocking device employs one or more of a fuse, a diode, a transistor, a switch, and a breaker and is configured to prevent dissipation of current from the secondary power source through a short at the first node.

19. The control system of claim 13, wherein a first protective element is disposed between the primary power source and the first controller, a second protective element is disposed between the secondary power source and the second controller, each of the first protective element and the second protective element having a current limit approximate to that of the fusible link.

20. The control system of claim 13, wherein the common bus is in electrical communication with an alternator configured to supply a bus voltage during normal operating conditions.