Method and apparatus for calibrating a position sensor used in engine control

• US 6,351,704 B1
• Filed: 03/31/2000
• Issued: 02/26/2002
• Est. Priority Date: 03/31/2000
• Status: Expired due to Term

• Current Assignee: Bombardier Motor Corp (Bombardier Incorporated)
• Original Assignee: Bombardier Motor Corporation Of America
• Inventors: Koerner, Scott A.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US09/540,691
• Time in Patent Office: 697 Days
• Field of Search: 123/396, 123/399, 123/400, 123/361, 701/102, 701/103, 701/114, 701/115, 73/17.5, 73/18.8
• US Class Current: 701/115
• CPC Class Codes: F02B 61/045 for outboard marine engines
• CPC Class Codes: F02D 11/106 Detection of demand or actuation
• CPC Class Codes: F02D 2250/16 End position calibration, i.e. calculation or measurement of actuator end positions, e.g. for throttle or its driving actuator
• CPC Class Codes: G01D 18/008 with calibration coefficients stored in memory
• CPC Class Codes: G01D 5/165 by relative movement of a point of contact or actuation and a resistive track

Abstract

A system and method is provided for calibrating a position sensor having a variable output corresponding to the variable position of a movable member. The system and method establishes for the position sensor a first output corresponding to a first given position of the movable member. The system and method stores the first output from a first operating session in memory to use in establishing the first output for a second operating session. The system and method may also use a biasing factor in establishing the first output for a second operating session. The system and method may also establish a second output corresponding to a second given position of the movable member as a function of a second output from a previous operating session or as a function of a biasing factor. The system and method may be used to control an internal combustion engine.

Claims

1. A method of calibrating a throttle control having a variable output corresponding to position of a movable member, comprising:

establishing a subsequent value for the first output of the throttle during a subsequent operating session as a function of the at least one first output stored in the memory from the previous operating session and a biasing factor.

2. The method as recited in claim 1, comprising:

assigning an initial value to the first output for use in subsequent operating sessions.

3. The method as recited in claim 1, comprising:

establishing a second output of a throttle corresponding to a second position of a moveable member, the second output being a function of a correction factor and at least one second output stored in memory from a previous operating session.

4. The method as recited in claim 1, the first output being an average of a plurality of first outputs stored in memory from previous operating sessions and a correction factor.

5. The method as recited in claim 1, comprising:

establishing a maximum output of the throttle corresponding to the first position;

establishing the maximum output as the first output if the subsequent value for the first output is greater than the maximum output; and

storing the first output in memory.

6. The method as recited in claim 5,

establishing a minimum output of the throttle corresponding to the first position;

determining an actual output of the throttle;

reestablishing the first output as the output corresponding to the first position of the member if the actual output is greater than or equal to the first output; and

establishing the actual output as the output corresponding to the first position of the member and storing the output corresponding to the first position of the member if the actual output is less than the first output and greater than or equal to the minimum output of the throttle corresponding to the first position, and

storing the first output in memory.

7. The method as recited in claim 6, comprising:

performing a diagnostic test if the first output is less than the minimum output value of the throttle corresponding to the first position.

8. A control system for an internal combustion engine, comprising:

a variable position throttle that produces an output corresponding to the variable position throttle position;

electronic memory; and

an electronic control unit that controls internal combustion engine operation in response to the variable output from the throttle, the electronic control unit being calibrated between a first output corresponding to a first position of the variable position throttle and a second output corresponding to a second position of the variable position throttle,

wherein a plurality of first outputs from a plurality of engine operating sessions are stored in memory or a plurality of second outputs from a plurality of engine operating sessions are stored in memory, and

the first output for a subsequent engine operating session is established as a function of the plurality of first outputs stored in memory from the plurality of engine operating sessions or the second output for a subsequent engine operating session is established as a function of the plurality of second outputs stored in memory from the plurality of previous engine operating sessions.

9. The control system as recited in claim 8, wherein the throttle:

establishes a minimum output of the throttle corresponding to the first position of the variable position throttle;

determines an actual output of the throttle;

reestablishes the first output as the output corresponding to the first position of the variable position throttle if the actual output is greater than or equal to the first output value; and

establishes the actual output as the output corresponding to the first position of the throttle if the actual output is less than the first output and greater than or equal to the minimum output of the throttle corresponding to the first position of the throttle.

10. The control system as recited in claim 8, comprising:

an indicator, to indicate to an operator the need to perform a diagnostic test if the first output is less than the minimum output of the throttle corresponding to the first position of the throttle.

11. The control system as recited in claim 8, wherein the first output or second output for a second engine operating session is established as a function of a biasing factor.

12. The control system as recited in claim 11, wherein the throttle:

establishes a maximum output of the throttle corresponding to the first position of the variable position throttle; and

establishes the maximum output as the first output for the second engine operating session if the first output is greater than the maximum output.

13. The control system as recited in claim 8, wherein the memory is configured as an array of memory elements, such that a first output from a previous engine operating session is stored in at least one of the memory elements.

14. The control system as recited in claim 13, comprising:

an index counter that repeats a defined number sequence and establishes at the start of each operating session the memory element in the array of memory elements that will store first output values during that engine operating session.

15. The control system as recited in claim 8, wherein the first position of the throttle corresponds to a neutral or idle position and the second position corresponds to a full load or wide-open throttle position.

16. The control system as recited in claim 15, wherein the internal combustion engine is controlled in response to a signal representing a position of the variable position throttle as a percentage of the full or wide-open throttle position.

17. The control system as recited in claim 16, wherein the signal representing the position of the variable position throttle as a percentage of the full load or wide-open throttle position is a function of the difference between the variable output and the first output, divided by the difference between the second output and the first output.

18. A motor system, comprising:

an internal combustion engine;

a variable position throttle, operable to provide an indication of a desired internal combustion engine operating condition and to produce a variable output corresponding to the variable position throttle position; and

an electronic control unit, having memory, that controls internal combustion engine operation in response to the variable output from the throttle, the electronic control unit being calibrated between a first output corresponding to a first position of the variable position throttle and a second output corresponding to a second position of the variable position throttle,

wherein the first output from a first engine operating session is stored in memory or the second output from a first engine operating session is stored in memory, and

the first output for a second engine operating session is established as a function of the first output stored in memory from the first engine operating session and a biasing factor or the second output for a second engine operating session is established as a function of the second output stored in memory from the first engine operating session and a biasing factor.

19. The motor system as recited in claim 18, wherein the throttle:

establishes a maximum output of the throttle corresponding to the first position of the variable position throttle; and

establishes the maximum output as the first output for the second engine operating session if the first output is greater than the maximum output value.

20. The motor as recited in claim 18, wherein the throttle:

establishes a minimum output of the throttle corresponding to the first position of the variable position throttle;

determines an actual output of the throttle;

reestablishes the first output as the output corresponding to the first position of the variable position throttle if the actual output is greater than or equal to the first output; and

establishes the actual output as the output corresponding to the first position of the throttle if the actual output is less than the first output and greater than or equal to the minimum output of the throttle corresponding to the first position of the throttle.

21. The motor system as recited in claim 18, wherein the memory is configured as an array of memory elements, such that a first output from a previous engine operating session is stored in at least one of the memory elements.

22. The motor system as recited in claim 21, comprising:

an index counter that repeats a defined number sequence and establishes at the start of each operating session the memory element in the array of memory elements that will store first output values during that engine operating session.

23. A method of operating a powered watercraft, comprising the acts of:

storing in a memory a plurality of first output values of a throttle, wherein a first output corresponds to an output of the throttle at a first throttle position; and

establishing a value for the first output for a current operating session as a function of the plurality of first output values stored in the memory.

24. The method as recited in claim 23, wherein each of the plurality of first output values were stored in memory during separate previous engine operating sessions.

25. The method as recited in claim 23, wherein establishing further comprises establishing the value for the first output as a function of a biasing factor.

26. The method as recited in claim 23, further comprising the act of establishing an actual throttle position as a function of the value of the first output of the current engine operating session and an actual output of the throttle at the actual throttle position.

27. The method as recited in claim 23, wherein the first throttle position comprises an idle position of the throttle.

28. The method as recited in claim 23, further comprising the acts of:

establishing a maximum output value corresponding to the first throttle position; and

identifying whether or not the current first output value is greater than the maximum output value during each operating session.

29. The method as recited in claim 28, further comprising the act of reestablishing the current first output value as the maximum output value when the current first output value is greater than the maximum output value.

30. The method as recited in claim 28, further comprising the act of storing the value of the first output of the current engine operating session in memory.

31. An internal combustion engine, comprising:

a variable position throttle operable to produce a throttle position signal; and

an electronic control system coupled to the throttle, the system being operable to control the speed of the engine by establishing actual throttle position as a percentage of full throttle, the percentage of full throttle being a function of the throttle position signal, a first output corresponding to a minimum throttle position, and a second output corresponding to a maximum throttle position, wherein the electronic control system automatically calibrates the first and second outputs during periodic operating sessions, the first output being calibrated as a function of a previous first output stored in memory from a previous engine operating session and the second output being calibrated as a function of a previous second output stored in memory from a previous engine operating session.

32. The engine as recited in claim 31, wherein the electronic control system calibrates the first and second outputs during each operating session.

33. The engine as recited in claim 31, wherein the electronic control system calibrates the first and second outputs as a function of a plurality of previous first and second outputs respectively, each of the plurality of previous first and second outputs corresponding to a different previous engine operating session.

34. The engine as recited in claim 31, wherein the electronic control system calibrates the first and second outputs as a function of a biasing factor.