System and method for automatically calibrating control devices for computer applications

• US 6,086,236 A
• Filed: 12/04/1997
• Issued: 07/11/2000
• Est. Priority Date: 12/04/1997
• Status: Expired due to Term

• Current Assignee: Logitech Europe S A (Logitech International SA)
• Original Assignee: Logitech, Inc. (Logitech International SA)
• Inventors: De Raad, Geurt B., Pchenitchnikov, Andrei E.
• Primary Examiner(s): Grant, William
• Assistant Examiner(s): Robinson, Victoria
• Application Number:
  US08/985,393
• Time in Patent Office: 950 Days
• Field of Search: 364/148.01, 364/528.1, 396/508, 396/463, 702/105
• US Class Current: 700/28
• CPC Class Codes: G05B 19/0423 Input/output
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry

Abstract

A control device provides software applications with a set of calibrated axis values that are indicative of a minimum, a center, and a maximum value on an axis. These values are continuously tracked and corrected while the control device is in use. As the user manipulates the control device, input axis values are monitored for calibration drift. When such calibration drift is detected, the minimum and the maximum axis values are automatically adjusted, while the center axis value is adjusted only when such center axis value remains substantially constant for a given time. If the operating system of the computer has default axis values for an uncalibrated axis, the adjusted axis values are scaled accordingly so as not to interfere with such default axis values.

Claims

1. A system for automatically calibrating an output of a control device for computer applications, comprising:

a first module, including an input and an output, for producing a minimum axis value, the input coupled to receive an input axis value from the control device;

a second module, including an input and an output, for producing a maximum axis value, the input coupled to receive the input axis value from the control device;

a third module, including an input and an output, the input coupled to receive the input axis value from the control device, the third module for producing a center axis value in response to the input axis value remaining substantially constant for a predetermined interval of time; and

a fourth module, including at least two inputs and an output, a first input coupled to receive the input axis value from the control device, a second input coupled to the outputs of the first, the second, and the third modules for receiving the minimum, the maximum, and the center axis values, respectively, the fourth module for processing the input axis value and the minimum, the maximum, and the center axis values to produce, at the output of the fourth module, a calibrated axis value that is scaled within a default axis value range.

2. The system of claim 1, further including:

a processor; and

a memory, coupled to the processor for storing the first, second, third, and fourth modules, the modules comprising a sequence of instructions, which, when executed by the processor, cause the processor to perform the steps of;

receiving the input axis value from the control device;

generating the minimum axis value and the maximum axis value from the input axis value and predetermined axis values;

generating the center axis value from the input axis value and the predetermined axis values if the input axis value remains substantially constant for a predetermined interval of time; and

processing the input axis value and the minimum, maximum, and center axis values to produce the calibrated axis value.

3. The system of claim 2, wherein the step of generating the minimum axis value further includes the steps of:

monitoring a first range of axis values having boundaries determined by the predetermined axis values; and

setting the minimum axis value equal to the input axis value when the input axis value is in the first range.

4. The system of claim 3, wherein a first boundary on the first range is equal to Min_theoretical and a second boundary on the first range is equal to Min_start, wherein ##EQU6##

5. The system of claim 4, wherein T is in the range from about 0.25 to about 0.5.

6. The system of claim 2, wherein the step of generating the maximum axis value further includes the steps of:

monitoring a second range of axis values having boundaries determined by the predetermined axis values; and

setting the maximum axis value equal to the input axis value when the input axis value is in the second range.

7. The system of claim 6, wherein a first boundary on the second range is equal to Max_theoretical and a second boundary on the second range is equal to Max_start, wherein ##EQU7##

8. The system of claim 7, wherein T is in the range from about 0.25 to about 0.5.

9. The system of claim 2, wherein the step of generating the center axis value further includes the steps of:

monitoring a third range of axis values having boundaries determined by the predetermined axis values; and

setting the center axis value equal to the input axis value when the input axis value is in the third range.

10. The system of claim 9, wherein a first boundary for the third range is equal to Min_acceptable, wherein Min_acceptable =(1-T) Mid_start and a second boundary for the third range is equal to Max_acceptable, wherein ##EQU8##

11. The system of claim 9, wherein the maximum axis value is set equal to the input axis value only after the input axis value remains substantially constant for a predetermined interval of time.

12. The system of claim 10, wherein T is in the range from about 0.1 to about 0.25.

13. The system of claim 2, wherein the input axis value is substantially constant if the condition |Axis_current -Axis_old |≦

V is satisfied.

14. The system of claim 13, wherein the tolerance V is equal to 1.

15. The system of claim 2, wherein the interval of time required for the input axis value to remain substantially constant is about 15 seconds.

16. The system of claim 2, wherein the step of processing the input axis value and the minimum, the maximum, and the center axis values to produce the calibrated axis value further includes the step of scaling the calibrated axis value to a value within the default axis value range.

17. The system of claim 16, wherein the calibrated axis value is scaled to fit in a first portion of the default range using the linear fitting

18. The system of claim 16, wherein the calibrated axis value is scaled to fit in a second portion of the default range by using the linear fitting

19. The system of claim 16, wherein the calibrated axis value is scaled to fit in the default range by using the linear fitting

20. A computer-readable medium having stored thereon instructions which, when executed by a processor, cause the processor to perform the steps of:

receiving an input axis value from a control device;

generating a minimum axis value and a maximum axis value from the input axis value and predetermined axis values;

generating a center axis value from the input axis value and the predetermined axis values if the input axis value remains substantially constant for a predetermined interval of time; and

processing the input axis value and the minimum, maximum, and center axis values to produce a calibrated axis value.

21. The computer-readable medium of claim 20, wherein the step of generating a minimum axis value further includes the steps of:

monitoring a first range of axis values having boundaries determined by the predetermined axis values; and

setting the minimum axis value equal to the input axis value when the input axis value is in the first range.

22. The computer-readable medium of claim 21, wherein a first boundary on the first range is equal to Min_theoretical and a second boundary on the first range is equal to Min_start, wherein ##EQU9##

23. The computer-readable medium of claim 22, wherein T is in the range from about 0.25 to about 0.5.

24. The computer-readable medium of claim 20, wherein the step of generating a maximum axis value further includes the steps of:

monitoring a second range of axis values having boundaries determined by the predetermined axis values; and

setting the maximum axis value equal to the input axis value when the input axis value is in the second range.

25. The computer-readable medium of claim 24, wherein a first boundary on the second range is equal to Max_theoretical and a second boundary on the second range is equal to Max_start, wherein ##EQU10##

26. The computer-readable medium of claim 25, wherein T is in the range from about 0.25 to about 0.5.

27. The computer-readable medium of claim 20, wherein the step of generating a center axis value further includes the steps of:

monitoring a third range of axis values having boundaries determined by the predetermined axis values; and

setting the center axis value equal to the input axis value when the input axis value is in the third range.

28. The computer-readable medium of claim 27, wherein a first boundary for the third range is equal to Min_acceptable, wherein Min_acceptable =(1-T)Mid_start and a second boundary for the third range is equal to Max_acceptable, wherein ##EQU11##

29. The computer-readable medium of claim 27, wherein the maximum axis value is set equal to the input axis value only after the input axis value remains substantially constant for a predetermined interval of time.

30. The computer-readable medium of claim 28, wherein T is in the range from about 0.1 to about 0.25.

31. The computer-readable medium of claim 20, wherein the input axis value is substantially constant if the condition |Axis_current -Axis_old |≦

V is satisfied.

32. The computer-readable medium of claim 31, wherein the tolerance V is equal to 1.

33. The computer-readable medium of claim 20, wherein the interval of time required for the input axis value to remain substantially constant is about 15 seconds.

34. The computer-readable medium of claim 20, wherein the step of processing the input axis value and the minimum, the maximum, and the center axis values to produce a calibrated axis value further includes the step of scaling the calibrated axis value to a value within a default range.

35. The computer-readable medium of claim 34, wherein the calibrated axis value is scaled to fit in a first portion of the default range using the linear fitting

36. The computer-readable medium of claim 34, wherein the calibrated axis value is scaled to fit in a second portion of the default range by using the linear fitting

37. The computer-readable medium of claim 34, wherein the calibrated axis value is scaled to fit in the default range by using the linear fitting

38. A method of automatically calibrating the output of a control device for computer applications, comprising the steps of:

receiving an input axis value from the control device;

generating a minimum axis value and a maximum axis value from the input axis value and predetermined axis values;

generating a center axis value from the input axis value and the predetermined axis values if the input axis value remains substantially constant for a predetermined interval of time; and

processing the input axis value and the minimum, maximum, and center axis values to produce a calibrated axis value.

39. The method of claim 38, wherein the step of generating a minimum axis value further includes the steps of:

monitoring a first range of axis values having boundaries determined by the predetermined axis values; and

setting the minimum axis value equal to the input axis value when the input axis value is in the first range.

40. The method of claim 39, wherein a first boundary on the first range is equal to Min_theoretical and a second boundary on the first range is equal to Min_start, wherein ##EQU12##

41. The method of claim 40, wherein T is in the range from about 0.25 to about 0.5.

42. The method of claim 38, wherein the step of generating a maximum axis value further includes the steps of:

monitoring a second range of axis values having boundaries determined by the predetermined axis values; and

setting the maximum axis value equal to the input axis value when the input axis value is in the second range.

43. The method of claim 42, wherein a first boundary on the second range is equal to Max_theoretical and a second boundary on the second range is equal to Max_start, wherein ##EQU13##

44. The method of claim 43, wherein T is in the range from about 0.25 to about 0.5.

45. The method of claim 38, wherein the step of generating a center axis value further includes the steps of:

monitoring a third range of axis values having boundaries determined by the predetermined axis values; and

setting the center axis value equal to the input axis value when the input axis value is in the third range.

46. The method of claim 45, wherein a first boundary for the third range is equal to Min_acceptable, wherein Min_acceptable =(1-T)Mid_start and a second boundary for the third range is equal to Max_acceptable, wherein ##EQU14##

47. The method of claim 45, wherein the maximum axis value is set equal to the input axis value only after the input axis value remains substantially constant for a predetermined interval of time.

48. The method of claim 46, wherein T is in the range from about 0.1 to about 0.25.

49. The method of claim 38, wherein the input axis value is substantially constant if the condition |Axis_current -A_old |≦

V is satisfied.

50. The method of claim 49, wherein the tolerance V is equal to 1.

51. The method of claim 38, wherein the interval of time required for the input axis value to remain substantially constant is about 15 seconds.

52. The method of claim 38, wherein the step of processing the input axis value and the minimum, the maximum, and the center axis values to produce a calibrated axis value further includes the step of scaling the calibrated axis value to a value within a default range.

53. The method of claim 52, wherein the calibrated axis value is scaled to fit in a first portion of the default range using the linear fitting

54. The method of claim 52, wherein the calibrated axis value is scaled to fit in a second portion of the default range by using the linear fitting

55. The method of claim 52, wherein the calibrated axis value is scaled to fit in the default range by using the linear fitting

56. A system for automatically calibrating the output of a control device for computer applications, comprising:

means for receiving an input axis value from the control device;

means for generating a minimum axis value and a maximum axis value from the input axis value and predetermined axis values;

means for generating a center axis value from the input axis value and the predetermined axis values if the input axis value remains substantially constant for a predetermined interval of time; and

means for processing the input axis value and the minimum, maximum, and center axis values to produce a calibrated axis value.