METHOD AND APPARATUS FOR THREE DIMENSIONAL CALIBRATION OF AN ON-BOARD DIAGNOSTICS SYSTEM

• US 20110251816A1
• Filed: 06/22/2011
• Published: 10/13/2011
• Est. Priority Date: 10/01/2008
• Status: Active Grant

• Current Assignee: Toyota Motor Corporation
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Tracey, Timothy D.
• Granted Patent: US 8,155,924 B2
• Time in Patent Office: Days
• US Class Current: 702/96
• CPC Class Codes: F02D 2200/1012 Engine speed gradient
• CPC Class Codes: F02D 2200/1015 Engines misfires
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• 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: F02D 41/2416 Interpolation techniques

Abstract

The present invention relates to a method and apparatus for three dimensional calibration of an on-board diagnostics system. In one embodiment, the present invention is a method for calibrating an on-board diagnostic system for an automobile including the steps of generating a three dimensional surface corresponding to an engine operating under a first condition, generating a three dimensional surface corresponding to the engine operating under a second condition, and generating a three dimensional threshold surface using the three dimensional surface corresponding to the engine operating under the first condition and the three dimensional surface corresponding to the engine operating under the second condition.

Claims

1. A method for calibrating an automobile diagnostic system with a calibration unit, the method comprising:

collecting first automobile data based on an automobile operating under a first condition;

generating interpolated first automobile data by performing three dimensional interpolation on the first automobile data; and

generating threshold automobile data using the interpolated first automobile data.

2. The method claim 1 further comprising:

collecting second automobile data based on an automobile operating under a second condition; and

generating interpolated second automobile data by performing three dimensional interpolation on the second automobile data;

wherein generating threshold automobile data uses the interpolated first automobile data or the interpolated second automobile data.

3. The method of claim 2 wherein the automobile operating under the first condition is an automobile operating under a non-malfunctioning condition and the automobile operating under the second condition is an automobile operating under a malfunctioning condition.

4. The method of claim 2 wherein the first automobile data and the second automobile data corresponds to crankshaft acceleration data.

5. The method of claim 2 wherein generating threshold automobile data includes adding or subtracting an offset to the interpolated first automobile data or the interpolated second automobile data.

6. The method of claim 5 further comprising generating an engine control unit (“

ECU”

) map using the threshold automobile data.

7. The method of claim 5 wherein the offset is user variable for generating desired threshold automobile data.

8. The method of claim 2 further comprising displaying the threshold automobile data as a three dimensional threshold surface on a display for visual inspection.

9. The method of claim 2 wherein:

collecting first automobile data includes using a first parameter and a second parameter, the value of the first parameter being varied while the value of the second parameter being held substantially constant; and

collecting second automobile data includes using the first parameter and the second parameter, the value of the first parameter being varied while the value of the second parameter being held substantially constant.

10. The method of claim 9 wherein:

collecting first automobile data includes using a plurality of values of the second parameter; and

collecting second automobile data includes using a plurality of values of the second parameter.

11. The method of claim 10 wherein the first parameter corresponds to engine load and the second parameter corresponds to engine speed.

12. A system for calibrating an automobile having an engine and an engine control unit (“

ECU”

), the system comprising;

a calibration unit configured to be connected to the engine or the ECU of the automobile, the calibration unit configured to

collect first engine data based on the engine operating under a first condition,

interpolate the first engine data three dimensionally, and

generate threshold engine data using the interpolation of the first engine data.

13. The system of claim 12 wherein the calibration unit is further configured to:

collect second engine data based on the engine operating under a second condition, and

interpolate the second engine data three dimensionally,

wherein the threshold engine data is generated using the interpolation of the first engine data or the interpolation of the second engine data.

14. The system of claim 13 wherein:

the first engine data and the second engine data corresponds to crankshaft acceleration data, and

each of the first engine data and each of the second engine data correlate with an engine speed value and an engine load value.

15. The system of claim 13 wherein the engine operating under the first condition is an engine operating under a non-malfunctioning condition and the engine operating under the second condition is an engine operating under a malfunctioning condition.

16. The system of claim 13 wherein generating the threshold engine data includes applying at least one offset to the interpolation of the first engine data or to the interpolation of the second engine data.

17. The system of claim 16 wherein the at least one offset is adjustable by a user of the calibration unit.

18. The system of claim 13 further comprising a display configured to display the interpolation of the first engine data, the interpolation of the second engine data or the threshold engine data for visual inspection.

19. The system of claim 12 wherein the ECU is configured to receive the threshold engine data from the calibration unit for monitoring the operation of the engine.

20. A method for calibrating an automobile engine monitoring system with a calibration unit, the method comprising:

collecting crankshaft acceleration data for an engine operating under a non-malfunctioning condition, each of the crankshaft acceleration data for the engine operating under the non-malfunctioning condition correlated with an engine speed value and an engine load value;

interpolating the crankshaft acceleration data for the engine operating under the non-malfunctioning condition in three dimensions;

collecting crankshaft acceleration data for an engine operating under a malfunctioning condition, each of the crankshaft acceleration data for the engine operating under the malfunctioning condition correlated with an engine speed value and an engine load value;

interpolating the crankshaft acceleration data for the engine operating under the malfunctioning condition in three dimensions; and

generating threshold automobile data by offsetting from the three dimensional interpolation of the crankshaft acceleration data for the engine operating under the non-malfunctioning condition or the three dimensional interpolation of the crankshaft acceleration data for the engine operating under the malfunctioning condition.