DISTANCE MEASUREMENT INSTRUMENT WITH SCANNING FUNCTION

• US 20190310352A1
• Filed: 06/21/2019
• Published: 10/10/2019
• Est. Priority Date: 12/05/2013
• Status: Active Grant

• Current Assignee: Trimble AB (Trimble Inc.)
• Original Assignee: Trimble AB (Trimble Inc.)
• Inventors: Nordenfelt, Mikael, Hertzman, Mikael
• Granted Patent: US 11,774,557 B2
• Time in Patent Office: Days
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G02B 26/108 having one or more prisms as scanning elements

Abstract

A measurement instrument is disclosed. The measurement instrument comprises a front lens assembly, a distance measurement module and a deflection module. The front lens assembly comprises an optical path along an instrument optical axis and the distance measurement module is configured to transmit and receive optical radiation along a measurement path. The deflection module is arranged between the distance measurement module and the front lens assembly to deflect the measurement path across the instrument optical axis.

Claims

1-16. -16. (canceled)

17. A measurement instrument, comprising:

an alidade, a base, and a center unit, wherein the center unit is mounted on the alidade for rotation about a first axis and on the base for rotation about a second axis,

a first controllable drive for rotating the center unit about the first axis,

a second controllable drive for rotating the alidade about the second axis,

a front lens assembly having an optical path along an instrument optical axis,

a distance measurement module operative to transmit optical radiation along a transmit path and receive optical radiation along a receive path,

a deflection module located within the center unit and positioned on an optical path between the distance measurement module and the front lens assembly, the deflection module having at least one deflection element configured to deflect the transmit path across the instrument optical axis so as to provide a scanning function,

a mixer positioned on the optical path between the distance measurement module and the front lens assembly, the mixer configured to merge the transmit path and the receive path to form a measurement beam, and

a synchronizer to synchronize operation of the first controllable drive, the second controllable drive, the deflection module, and the distance measurement module so as to obtain a grid of distance measurements having a selected angular spacing.

18. The instrument of claim 17, wherein the at least one deflection element is configured to provide rotational motion such that at least one of the transmit path or the receive path is deflected with rotation of the at least one deflection element.

19. The instrument of claim 17, further comprising a drive element operative to rotate the at least one deflection element.

20. The instrument of claim 19, wherein the drive element is operative to produce at least one of an oscillating rotational motion of the at least one deflection element, a continuous rotational motion of the at least one deflection element, or a directed rotational motion of the at least one deflection element to a selected orientation.

21. The instrument of claim 19, further comprising a drive controller operative to control rotational motion of the at least one deflection element by the drive element.

22. The instrument of claim 17, further comprising an angle sensor operative to detect an angle of rotation of the at least one deflection element.

23. The instrument of claim 17, wherein the at least one deflection element is configured to provide translational displacement such that at least one of the transmit path or the receive path is deflected with translational displacement of the at least one deflection element.

24. The instrument of claim 17, further comprising a drive element operative to translate the at least one deflection element.

25. The instrument of claim 24, wherein the drive element is operative to produce a translational displacement of the at least one deflection element.

26. The instrument of claim 24, further comprising a drive controller operative to control translational displacement of the at least one deflection element by the drive element.

27. The instrument of claim 17, further comprising a displacement sensor operative to detect a translational displacement of the at least one deflection element.

28. The instrument of claim 17, wherein the at least one deflection element comprises at least one of a prism, a multi-faceted mirror, or a disk having a scalloped curving mirrored surface.

29. The instrument of claim 17, further comprising a deflection lens assembly, wherein optical displacement due to the at least one deflection element is converted to optical deflection, to produce angular deflection of the transmit path across the instrument optical axis.

30. The instrument of claim 17, wherein the distance measurement module is operated at a controlled repetition rate to acquire a sequence of distance measurements, the at least one deflection element is operated at a controlled deflection rate, or a deflection plane is oriented such that a sweep of the instrument optical axis at a given velocity about one of the first axis and the second axis enables acquisition of the sequence of distance measurements spaced apart in a two-dimensional polar grid.

31. The instrument of claim 17, wherein the at least one deflection element is configured to displace the transmit path and wherein the front lens assembly is configured to convert a displacement of the transmit path to an angular deflection across the instrument optical axis.

32. A measurement instrument, comprising:

an alidade, a base, and a center unit, wherein the center unit is mounted on the alidade for rotation about a first axis and on the base for rotation about a second axis,

a first controllable drive for rotating the center unit about the first axis,

a second controllable drive for rotating the alidade about the second axis,

a front lens assembly having an optical path along an instrument optical axis,

a distance measurement module operative to transmit optical radiation along a transmit path and receive optical radiation along a receive path,

a deflection module located within the center unit and positioned on an optical path between the distance measurement module and the front lens assembly, the deflection module having at least one deflection element configured to deflect at least one of the transmit path or the receive path across the instrument optical axis so as to provide a scanning function, and

a synchronizer to synchronize operation of the first controllable drive, the second controllable drive, the deflection module, and the distance measurement module so as to obtain a grid of distance measurements having a selected angular spacing.

33. The instrument of claim 32, wherein the at least one deflection element is configured to provide rotational motion such that at least one of the transmit path or the receive path is deflected with rotation of the at least one deflection element.

34. The instrument of claim 32, wherein the at least one deflection element is configured to provide translational displacement such that at least one of the transmit path or the receive path is deflected with translational displacement of the at least one deflection element.

35. A measurement instrument, comprising:

an alidade, a base, and a center unit, wherein the center unit is mounted on the alidade for rotation about a first axis and on the base for rotation about a second axis orthogonal to the first axis,

a first controllable drive configured to rotate the center unit about the first axis,

a second controllable drive configured to rotate the alidade about the second axis,

a front lens assembly having an optical path along an instrument optical axis,

a distance measurement module configured to transmit optical radiation along a transmit path and receive optical radiation along a receive path,

a deflection module located within the center unit and positioned on an optical path between the distance measurement module and the front lens assembly, the deflection module having a deflection element configured to deflect the transmit path across the instrument optical axis, and

a synchronizer configured to synchronize operation of the first controllable drive, the second controllable drive, the deflection module, and the distance measurement module so as to obtain a grid of distance measurements having a selected angular spacing.

36. The instrument of claim 35, wherein the deflection element is configured to provide at least one of rotational motion such that the transmit path is deflected with rotation of the deflection element or translational displacement such that the transmit path is deflected with translational displacement of the deflection element.