System and method for enhanced engine monitoring and protection

• US 6,131,539 A
• Filed: 06/30/1999
• Issued: 10/17/2000
• Est. Priority Date: 06/30/1999
• Status: Expired due to Term

• Current Assignee: MTU America, Inc. (Rolls-Royce Holdings Plc)
• Original Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Inventors: Thomas, Eric D.
• Primary Examiner(s): Wolfe, Willis R.
• Assistant Examiner(s): Harris, Katrina B.
• Application Number:
  US09/345,052
• Time in Patent Office: 475 Days
• Field of Search: 123/41.15, 123/196 S, 123/198 D, 701/112
• US Class Current: 123/41.15
• CPC Class Codes: F01M 1/22 rendering machines or engines inoperative or idling on pressure failure
• CPC Class Codes: F01P 11/18 concerning coolant pressure, coolant flow, or liquid-coolant level
• CPC Class Codes: F01P 2025/04 Pressure
• CPC Class Codes: F01P 2025/62 Load
• CPC Class Codes: F01P 2025/64 Number of revolutions
• CPC Class Codes: F01P 2031/22 using warning lamps
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system and method for monitoring and controlling an engine based on an engine fluid pressure include sensing an engine fluid pressure, determining a current value for an engine operating parameter, determining whether the engine fluid pressure has crossed a first threshold corresponding to the current value of the engine operating parameter, determining whether the engine fluid pressure has crossed a second threshold corresponding to the current value of the engine operating parameter, generating a warning signal when the fluid pressure has crossed the first threshold but has not crossed the second threshold, and generating a shutdown signal when the fluid pressure has crossed the second threshold. In one embodiment, the second threshold is determined based on the first threshold by applying a constant offset value.

Claims

1. A method for controlling an engine, the method comprising:

sensing an engine fluid pressure;

determining a current value for an engine operating parameter;

determining whether the engine fluid pressure has crossed a first threshold corresponding to the current value of the engine operating parameter;

determining whether the engine fluid pressure has crossed a second threshold corresponding to the current value of the engine operating parameter;

generating a warning signal when the fluid pressure has crossed the first threshold but has not crossed the second threshold; and

generating a shutdown signal when the fluid pressure has crossed the second threshold.

2. The method of claim 1 wherein the step of sensing an engine fluid pressure comprises sensing an engine coolant pressure.

3. The method of claim 1 wherein the step of sensing an engine fluid pressure comprises sensing an engine oil pressure.

4. The method of claim 1 wherein the step of generating a warning signal comprises activating a visual indicator.

5. The method of claim 1 wherein the step of generating a shutdown signal comprises reducing available engine torque.

6. The method of claim 1 wherein the step of determining a current value for an engine operating parameter comprises determining a current engine speed.

7. The method of claim 1 wherein the step of determining whether the engine fluid pressure has crossed a second threshold comprises determining the second threshold based on the first threshold for the current value of the engine operating parameter.

8. The method of claim 1 wherein the step of determining whether the engine fluid pressure has crossed a first threshold comprises determining whether the engine fluid pressure is below the first threshold.

9. A system for monitoring and controlling an engine, the system comprising:

an engine fluid pressure sensor for measuring an engine fluid pressure;

an engine operating parameter sensor for measuring an engine operating parameter; and

a controller in communication with the engine fluid pressure sensor and the engine operating parameter sensor, the microprocessor including control logic for comparing the engine fluid pressure to an associated first engine pressure threshold, comparing the engine fluid pressure to an associated second engine pressure threshold, and generating an engine warning signal when the engine fluid pressure crosses the first threshold but before the engine fluid pressure crosses the second threshold.

10. The system of claim 9 wherein the engine fluid pressure is an engine coolant pressure.

11. The system of claim 9 wherein the engine fluid pressure is an engine oil pressure.

12. The system of claim 9 further comprising:

an engine warning indicator in communication with the controller, the engine warning indicator being activated when the engine fluid pressure is below the first threshold to alert an engine operator.

13. The system of claim 9 wherein the controller further comprises control logic for generating an engine shutdown signal when the engine fluid pressure crosses the second threshold.

14. The system of claim 13, wherein the controller further comprises control logic for controlling the engine based on the engine shutdown signal.

15. A computer readable storage medium having information stored thereon representing instructions executable by an engine controller in communication with at least one pressure sensor for detecting an engine malfunction, the computer readable storage medium comprising:

instructions for determining at least one fluid pressure;

instructions for determining a current value for an engine operating parameter;

instructions for determining a first pressure threshold value corresponding to the current value of the engine operating parameter;

instructions for determining a second pressure threshold value based on the first threshold;

instructions for comparing the at least one fluid pressure to the first and second thresholds to determine when the fluid pressure crosses the first and second thresholds;

instructions for generating an engine warning signal indicative of the fluid pressure crossing the first pressure threshold; and

instructions for generating an engine shut-down signal indicative of the fluid pressure crossing the second pressure threshold.

16. The computer readable storage medium of claim 15 further comprising:

instructions for initiating a timer when one of the first and second thresholds is crossed.