Portable measurement apparatus for determinging the dimensions of an object and associated method

• US 6,373,579 B1
• Filed: 05/26/1999
• Issued: 04/16/2002
• Est. Priority Date: 05/26/1999
• Status: Expired due to Term

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Orr, Raymond Andrew, Ober, Lawrence Richard
• Primary Examiner(s): Rosenberger, Richard A.
• Application Number:
  US09/320,357
• Time in Patent Office: 1,056 Days
• Field of Search: 356/3.09, 356/379, 356/380, 356/381, 356/383, 356/627, 356/634, 356/635, 356/628, 356/629, 250/559.07, 250/559.38
• US Class Current: 356/627
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/46 Indirect determination of position data

Abstract

The present invention provides an apparatus and method for determining the dimension of an object. The apparatus of the present invention includes a transmitter that is positioned at a first point of interest on an object. The transmitter transmits a scanning light beam rotated at a predetermined angular velocity. Located at a second point of interest on the object is a target. At least a portion of the target defines a first plane that reflects the scanning light beam as the scanning light beam traverses across the target. To receive the reflected signal from the target, the apparatus of the present invention further includes a receiver positioned at the first point of interest. Additionally, the apparatus of the present invention includes a processor for processing the reflected signal and determining the dimensions of the object. In operation, the scanning light beam scans the target, where the radius of the arc that the light beam traverses across the target defines the dimension of the object. To determine the radius of the arc, the apparatus of the present invention uses the known width of the target, the angular velocity of the scanning light beam, and the time required for the scanning light beam to traverse the target. In addition to determining a dimension of an object, the present invention also provides apparatus and method for calibrating the measurement system and determining when the system is in steady state operation.

Claims

1. An apparatus for measuring a volume of an object as represented by different dimensions of the object defined by the distance between two points of interest at different locations on the object, wherein said apparatus comprises:

a transmitter positioned at a first point of interest, wherein said transmitter produces a scanning light beam rotated at a predetermined angular velocity;

a target for positioning at different points of interest on the object, wherein at least a portion of said target defines a first plane, and wherein at least a portion of said target along the first plane reflects the scanning light beam as the scanning light beam traverses the first plane of said target;

a receiver positioned at the first point of interest, wherein said receiver receives a reflected light beam reflected by the first plane of said target; and

a processor in electrical communication with said receiver, wherein as said target is placed at different points of interest on said object such that the first point of interest and the different points of interest respectively define the width height, and length of the object said processor determines the width, height, and length of the object by calculating the distance between the first point of interest and the different points of interest, and wherein said processor multiplies the width, height, and length together to thereby determine the volume of the object.

2. An apparatus according to claim 1, wherein the first plane of said target has a known width, wherein said processor further comprises a counter in electrical communication with said receiver, and wherein said counter accumulates the time required for the scanning light beam to traverse the known width of the first plane of said target.

3. An apparatus according to claim 1, wherein the first plane of said target has a known width, and wherein said processor determines the dimension of the object defined by the distance between said transmitter and said target based on the known width of the first plane of said target, the angular velocity at which said transmitter rotates the scanning light beam, and the time required for the scanning light beam to traverse the known width of the first plane of said target.

4. An apparatus according to claim 1, wherein said transmitter transmits a scanning laser beam.

5. An apparatus according to claim 1, wherein said transmitter rotates the light beam through a rotational arc.

6. An apparatus according to claim 5, wherein the first plane of said target is aligned with said transmitter such that a light beam intersecting a midpoint of the rotational arc is substantially perpendicular to the first plane of said target.

7. An apparatus according to claim 6, wherein the first plane of said target has a known width and a midpoint, and wherein the midpoint of said target is substantially aligned with a light beam intersecting the midpoint of the rotational arc.

8. An apparatus according to claim 5, wherein the first plane of said target has a known width and a midpoint, wherein said transmitter in an alignment mode provides a stationary light beam that intersects the midpoint of the rotational arc such that the midpoint of said target can be aligned to the stationary light beam to thereby align said target and said transmitter.

9. An apparatus according to claim 1, wherein said target comprises at least two reflective transition points spaced apart at a known distance, wherein the scanning light beam traverses across the reflective transition points, and wherein said receiver receives signals indicating when the scanning light beam traverses the reflective transition points.

10. An apparatus according to claim 9, wherein the reflective transition points of said target comprise a plurality of nonreflective portions spaced apart from each other by reflective portions having known widths such that each nonreflective portion separated by a reflective portion of known width defines a target.

11. An apparatus according to claim 10, wherein as the scanning light beam traverses across each of the plurality of reflective portions of said target, said receiver receives a respective reflected light beam associated with each of the plurality of reflective portions, wherein said processor determines a respective distance between the first point of interest and the point of interest where said target is located based on each of the reflected signals from each of the reflective portions of said target, and wherein said processor averages these determined respective distances together to determine an average distance between the first point of interest where said transmitter and receiver are located and the point of interest at which said target is located.

12. An apparatus according to claim 1, wherein said target comprises a reflective portion and a nonreflective portion having a known width, wherein the scanning light beam traverses across the target and the receiver receives signals indicating when the scanning light beam traverses from the reflective portion to the nonreflective portion and when the scanning light beam traverses from the nonreflective portion to the reflective portion of said target.

13. An apparatus according to claim 1 further comprising a display electrically connected to said processor, wherein said display receives and displays the determined dimension of the object.

14. An apparatus according to claim 1 further comprising an indicator electrically connected to said processor, wherein said indicator indicates to a user when said processor has determined the dimension of the object.

15. An apparatus according to claim 1, wherein said target is positioned at a known distance from said transmitter, wherein said transmitter in a calibration mode scans said target with the scanning light beam, wherein said receiver receives a reflected signal from said target, and wherein said processor determines the time required for said transmitter to scan said target for the known distance between said target and transmitter and stores the time and known distance in a calibration table.

16. An apparatus according to claim 15, wherein said target is systematically placed at differing known distances from said transmitter, wherein said processor determines a time required for the scanning light beam to traverse the target at each of the differing known distances and stores the time and known distance in a calibration table.

17. An apparatus according to claim 1, wherein said processor in a steady state determination mode repeatedly calculates the distance between the two points of interest and compares the calculated distances to thereby determine when said transmitter produces a scanning light beam rotated at a predetermined angular velocity thereby indicating that the transmitter is operating in a steady state mode.

18. An apparatus according to claim 1 further comprising a sensor connected to said processor for sensing the operating temperature of said apparatus and a memory device.

19. An apparatus according to claim 18, wherein said memory device contains a stored table of calibration data, and wherein said processor compensates for the calculated dimension of the object based on the operating temperature of the apparatus and the table of calibration data.

20. An apparatus according to claim 17, wherein said apparatus is at a predetermined temperature, wherein said target is positioned at a known distance from said transmitter, wherein said transmitter in a temperature calibration mode scans said target with the scanning light beam, wherein said receiver receives a reflected signal from said target, and wherein said processor determines the time required for said transmitter to scan said target for the known distance between said target and transmitter and stores the time, temperature, and known distance in a calibration table.

21. An apparatus according to claim 1 further comprising a memory device. wherein said processor stores the dimension of the object in said memory device.

22. An apparatus according to claim 1 further comprising a housing having securing means for housing the transmitter and receiver and a reference point located on an external portion of said housing, wherein the reference point engages the first point of interest of the object and is a defined distance from said transmitter, and wherein said processor compensates for the distance between the reference point and said transmitter in determining the dimension of the object.

23. A method for measuring a volume of an object as represented by different dimensions of the object defined by the distance between two points of interest at different locations on the object, wherein said method comprises the steps of:

transmitting a scanning light beam rotated at a predetermined angular velocity from a first point of interest;

systematically positioning a target at different points of interest on the object such that the first point of interest and the different points of interest respectively define the width, height, and length of the object, wherein at least a portion of said target defines a first plane for reflecting the scanning light beam;

at least partially reflecting the scanning light beam as the scanning light beam traverses the first plane of the target at each different point of interest on the object;

receiving at the first point of interest a reflected light beam reflected by the first plane of the target as the target is placed at each different point of interest on the object;

determining the width, height, and length of the object by calculating the distance between the first point of interest and the different points of interest; and

multiplying the width, height, and length to thereby determine the volume of the object.

24. A method according to claim 23, wherein the first plane of said target has a known width, and wherein said method further comprises the step of counting the time required for the scanning light beam to traverse the known width of the first plane of the target.

25. A method according to claim 23, wherein the first plane of said target has a known width, and wherein said determining step comprising determining the dimension of the object based on the known width of the first plane of the target, the angular velocity at which the scanning light beam is rotated, and the time required for the scanning light beam to traverse the known width of the first plane of the target.

26. A method according to claim 23, wherein said transmitting step comprises transmitting a scanning laser beam.

27. A method according to claim 23, wherein said transmitting step comprises rotating the light beam through a rotational arc.

28. A method according to claim 27 further comprising the step of aligning the first plane of the target with the transmitter such that a light beam intersecting a midpoint of the rotational arc is substantially perpendicular to the first plane of the target.

29. A method according to claim 28, wherein the first plane of the target has a known width and a midpoint, and wherein said aligning step comprises substantially aligning the midpoint of the target with a light beam intersecting the midpoint of the rotational arc.

30. A method according to claim 27, wherein the first plane of the target has a known width and a midpoint, wherein said transmitting step in an alignment mode comprises transmitting a stationary light beam that intersects the midpoint of the rotational arc, and wherein said aligning step comprises aligning the midpoint of the target to the stationary light beam to thereby align the target and the transmitter.

31. A method according to claim 23, wherein the target includes at least two reflective transition points spaced apart at a known distance, wherein said transmitting step comprises transmitting a scanning light beam that traverses across the reflective transition points, and wherein said reflecting step comprising reflecting the scanning light beam as it traverses the reflective transition points.

32. An apparatus according to claim 31, wherein the reflective transition points of the target comprises a plurality of nonreflective portions spaced apart from each other by reflective portions having known widths such that each nonreflective portion is separated by a reflective portion of known width defines a target, wherein as the scanning light beam traverses across each of the plurality of reflective portions of the target, said receiving step receives a respective reflected light beam associated with each of the plurality of reflective portions, wherein said determining step determines a respective distance between the first point of interest and the point of interest where the target is located based on each of the reflected signals from each of the reflective portions of the target, and wherein said determining step averages these determined respective distances together to determine an average distance between the first point of interest and the point of interest at which the target is located.

33. A method according to claim 23, wherein said target comprises a reflective portion and a nonreflective portion having a known width, wherein said transmitting step comprises transmitting a scanning light beam that traverses across the target, and wherein said reflecting step comprises reflecting signals indicating when the scanning light beam traverses from the reflective portion to the nonreflective portion and when the scanning light beam traverses from the nonreflective portion to the reflective portion of the target.

34. A method according to claim 23 further comprising the step of displaying the determined dimension of the object determined in said determining step.

35. A method according to claim 23 further comprising the step of indicating to a user when said determining step determines the dimension of the object.

36. A method according to claim 23 further comprising the step of placing the transmitter and target at a known distance apart, wherein said transmitting step in a calibration mode comprises transmitting a scanning light beam at the target, wherein said reflecting step comprises reflecting a reflected signal, wherein said receiving step comprises receiving the reflected signal, and wherein said determining step comprises determining the time required for the scanning light beam to scan the target for the known distance.

37. A method according to claim 36, wherein said placing step comprises systematically placing the transmitter and target at different known distances, wherein said determining step comprises determining the time required for the scanning light beam to scan the target for each of the known distances, and wherein said method further comprises storing the time required for the scanning light beam to scan the target and the known distances in a table.

38. A method according to claim 23, wherein said determining step in a steady state determination mode comprises repeatedly determining the distance between the two points of interest, and wherein said method further comprises the step of comparing the distances determined in said determining step to thereby determine when the transmitting step produces a scanning light beam rotated at a predetermined angular velocity.

39. A method according to claim 23 further comprising sensing the operating temperature at which the scanning light beam is transmitted.

40. A method according to claim 39 further comprising storing a table of temperature calibration data, and wherein said method further comprises after said determining step the step of compensating the determined dimension of the object from said determining step based on the operating temperature scanning laser beam and the table of calibration data.

41. A method according to claim 39 further comprising the step of placing the apparatus at a predetermined temperature and placing the target at a known distance from the transmitter, wherein said transmitting step transmits a scanning light beam at said target, wherein said receiving step receives a reflected signal from the target, wherein said determining step determines the time required for said transmitter to scan the target for the known distance between the target and transmitter, and wherein said method further comprising storing the time, temperature, and known distance in a calibration table.

42. A method according to claim 23 further comprising after said determining step the step of storing the dimension of the object.

43. A method according to claim 23 wherein said transmitting step comprises transmitting a scanning light beam from an offset point located at a known reference distance from the first point of interest, and wherein said method further comprises the step of compensating the dimension of the object determined in said determining step for the known reference distance between the offset point and the first point of interest.