Presence sensing system and method

• US 20020041231A1
• Filed: 08/21/2001
• Published: 04/11/2002
• Est. Priority Date: 08/25/2000
• Status: Active Grant

• Current Assignee: Omron Scientific Technologies Incorporated (Omron Corporation)
• Original Assignee: Scientific Technologies Incorporated (Omron Corporation)
• Inventors: Drinkard, John
• Granted Patent: US 6,753,776 B2
• Time in Patent Office: Days
• US Class Current: 340/541
• CPC Class Codes: G08B 13/193 using focusing means

Abstract

A presence sensing system provides one or more visible indicators useful for indicating a relative location of objects sensed within the scanning field of view. For example, the system may have an indicator array or an integrated display assembly in which individual indicators or indicator positions correspond to defined portions of the system'"'"'s field of view. In this manner, the presence sensing system can indicate where one or more sensed objects lie within its field of view. The system may monitor or otherwise scan an angular field of view and may have an indicator array comprising a plurality of individual indicators, each one corresponding to a portion of the monitored area. With this configuration, the system selectively illuminates or otherwise activates those indicators in the array corresponding to the relative angles of detected objects within its field of view.

Claims

1. A presence sensing system for monitoring a protected area in machine guarding applications, said presence sensing system comprising:

a detection system to detect objects in at least a portion of the protected area;

one or more indicators to visibly indicate relative positions of objects detected within the protected area.

2. The presence sensing system of claim 1 wherein said one or more indicators comprise an array of indicators.

3. The presence sensing system of claim 2 wherein each indicator in said array of indicators is associated with a sector of said protected area, such that said indicator is activated in response to an object being detected in the associated sector.

4. The presence sensing system of claim 2 wherein said array of indicators functions as a detection angle indicator by indicating detection angles of objects detected within the protected area.

5. The presence sensing system of claim 2 wherein said array of indicators comprises one or more displays, and wherein individual indicators in said array comprise selectively activated regions of said one or more displays.

6. The presence sensing system of claim 2 wherein said array of indicators comprises a plurality of discrete indicators.

7. The presence sensing system of claim 6 wherein each said discrete indicator comprises an LED.

8. The presence sensing system of claim 2 wherein said array of indicators comprises an arrangement of indicators corresponding to a sectorized layout of the protection area.

9. The presence sensing system of claim 8 wherein said arrangement of indicators comprises an arced array of indicators.

10. The presence sensing system of claim 1 further comprising a controller to selectively activate said one or more indicators in dependence on where an object is detected in said protected area.

11. The presence sensing system of claim 10 wherein said controller selectively activates said one or more indicators responsive to said detection system detecting objects in the protected area based on associating given indicators with given sectors in the protected area.

12. The presence sensing system of claim 1 further comprising a machine interface to assert an output signal responsive to detecting one or more objects in the protected area.

13. The presence sensing system of claim 1 wherein said detection system comprises an array-based detection system to monitor at least a portion of the protected area.

14. The presence sensing system of claim 13 wherein said array-based detection system comprises an array of detection circuits.

15. The presence sensing system of claim 1 wherein said detection system comprises:

a scanning laser to sweep a laser beam through at least a portion of the protected area; and

a detection circuit responsive to return reflections of the laser beam.

16. The presence sensing system of claim 15 wherein said one or more indicators function as beam angle indicators operative to indicate relative angles at which said presence sensing system detects objects within the protected area.

17. The presence sensing system of claim 1 wherein said detection system monitors a field of view, and wherein said field of view comprises at least a portion of the protected area.

18. The presence sensing system of claim 17 wherein said field of view comprises a plurality of sectors and said one or more indicators comprises a plurality of indicators configured in an array corresponding to said sectors.

19. The presence sensing system of claim 18 wherein individual ones of said plurality of indicators correspond to specific portions of said field of view, and wherein said presence sensing system activates one or more said indicators based on the sectors in which an object is detected in the field of view.

20. The presence sensing system of claim 1 wherein said one or more indicators function as diagnostic indicators operative to indicate diagnostic information to an operator of said presence sensing system.

21. The presence sensing system of claim 20 wherein said one or more indicators function as said diagnostic indicators based on indicating binary values representing encoded diagnostic information.

22. The presence sensing system of claim 1 wherein said presence sensing system controls said one or more indicators based on distances of objects detected within the protected area.

24. The machine guarding system of claim 23 wherein the signal generator generates a laser beam signal that is directed through at least a portion of the protected area.

25. The machine guarding system of claim 23 wherein the signal generator comprises a scanning laser that sweeps a laser beam across at least a portion of the protected area;

and wherein the at least one indicator comprises a series of indicators disposed along a curved path and wherein the respective indicators are operative to indicate the relative positions of one or more objects detected by the laser beam signal.

26. The machine guarding system of claim 25 wherein the protected area comprises a plurality of sectors and said scanning laser sweeps the laser beam across the sectors, and wherein individual ones of said series of indicators correspond to designated ones of the sectors, such that said machine guarding system activates one or more of said series of indicators depending on in which sectors objects are detected.

28. The presence sensing system of claim 27 wherein said plurality of indicators comprise an array of discrete indicators.

29. The presence sensing system of claim 28 wherein said array of discrete indicators comprises an arrangement of individual indicators having an arrangement corresponding to said associated sectors comprising the field of view.

30. The presence sensing system of claim 27 wherein said plurality of indicators comprises at least one visible display having a plurality of indicator positions that may be selectively activated by said controller.

31. The presence sensing system of claim 27 wherein said plurality of indicators comprises an array of indicators, each said indicator corresponding to an associated sector of said field of view, such that said array of indicators functions as a detection angle indicator, and wherein said presence sensing system indicates a relative position of objects detected in the field of view based on indicating detection angles to the objects via said detection angle indicator.

23. A machine guarding system for detecting and locating objects within a protected area of a machine, comprising:

a signal generator for generating a signal, directing the signal through at least a portion of the protected area, and detecting the presence of an object within the protected area; and

at least one indicator for indicating the relative position of an object within the protected area in response to the object being detected by the signal.

27. A presence sensing system comprising:

a detection system operative to detect a presence of one or more objects within a field of view of said presence sensing system;

a plurality of indicators to visibly indicate a relative position of an object detected within the field of view; and

a controller to associate individual ones of said indicators with corresponding sectors of the field of view, and to activate selected ones of said indicators in dependence on the sectors in which objects are detected by said presence sensing system.

32. A method of providing location information for objects detected within a field of view of a presence sensing system having a plurality of detection indicators, the method comprising:

associating individual ones of said detection indicators with corresponding areas within said field of view; and

activating one or more of said detection indicators based on where objects are detected within said field of view.

33. The method of claim 32 wherein said field of view comprises a plurality of sectors, and wherein associating individual ones of said detection indicators with corresponding areas within said field of view comprises associating successive ones of said detection indicators with successive ones of said sectors.

34. The method of claim 32 wherein said detection indicators comprise an array of indicators corresponding to a plurality of sectors within an angular field of view, and further comprising operating said detection indicators as detection angle indicators, such that said location information comprises an indication of relative angle between said presence sensing system and detected objects.

35. The method of claim 32 further comprising indicating system information via said detection indicators by activating said detection indicators in coded patterns corresponding to defined system information codes.

36. The method of claim 32 further comprising controlling activation of said detection indicators based on a distance to a detected object.

37. The method of claim 32 further comprising controlling activation of said detection indicators based on a current operating mode of said presence sensing system.

38. The method of claim 37 wherein controlling activation of said detection indicators based on a current operating mode of said system comprises activating one or more ones of said detection indicators in response to objects detected within said field of view during at least one mode of said presence sensing system.

40. The method of claim 39 further comprising detecting objects within the field of view by sweeping a laser beam through said sectors comprising the field of view and detecting return reflections from objects within said sectors.

41. The method of claim 40 wherein sweeping a laser beam through said sectors and detecting return reflections from objects within said sectors comprises:

emitting laser beam pulses at defined angular steps, said steps dividing each one of said sectors into discrete detection points; and

detecting return reflections at each said angular step.

42. The method of claim 41 wherein associating successive ones of said detection angle indicators with successive sectors comprising the field of view comprises assigning a given one of said detection angle indicators to a given range of said angular steps, such that one or more discrete detection points correspond to each one of said detection angle indicators.

43. The method of claim 39 further comprising physically arranging said detection angle indicators along a curved path.

44. The method of claim 43 further comprising defining said curved path such that said array corresponds to an included angle of the field of view.

39. A method of indicating relative detection angles between a presence sensing system having an array of detection angle indicators and an object detected in a field of view monitored by said presence sensing system, the method comprising:

associating successive ones of said detection angle indicators with successive sectors comprising the field of view; and

activating the detection angle indictors associated with sectors in which said presence sensing system detects one or more objects, such that said presence sensing system indicates relative detection angles to said one or more objects.