Surveying instrument

Abstract

To provide a surveying instrument capable of shortening the measurement time.SOLUTION: A surveying instrument comprises: a distance measurement section 19 including a light projection section 28 for emitting distance measurement light and a light reception section 31 for receiving reflected distance measurement light from an object to be measured; a deflection optical member configured to be rotated in a vertical direction via a hollow vertical rotation shaft 11; a vertical rotation driving section 13 for rotating the deflection optical member in the vertical direction; a frame section 5 provided with the deflection optical member; a horizontal rotation driving section 8 for rotating the frame section 5 in a horizontal direction; an image pickup section 21 configured to capture an image of the object to be measured based on external light passing through the vertical rotation shaft; and an arithmetic control section 17 configured to calculate a distance to the object to be measured based on a light reception result of the reflected distance measurement light received by the light reception section 31. The distance measurement section 19 and the image pickup section 21 are disposed at positions opposite to each other across the deflection optical member. The deflection optical member has two reflection surfaces for reflecting the distance measurement light, the reflected distance measurement light, and the external light at a right angle. The arithmetic control section 17 simultaneously performs distance measurement via one of the reflection surfaces and image capture via the other reflection surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surveying instrument capable of acquiring three-dimensional point cloud data and images of a measurement object. [Background technology]

[0002] A 3D laser scanner is one example of a surveying device used to obtain the shape of an object to be measured and 3D point cloud data. Another type of surveying device is a laser scanner with a built-in or external camera, and by using a laser scanner and a camera, it is possible to obtain an image with 3D coordinates.

[0003] However, in conventional surveying devices, measurement by a laser scanner and image capture by a camera are carried out separately, so one process cannot be carried out until the other process is completed, which takes a long time to measure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-117013 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a surveying instrument that reduces the measurement time. [Means for solving the problem]

[0006] The present invention relates to a surveying instrument comprising a distance measurement unit having a light-projecting unit that emits distance-measuring light and a light-receiving unit that receives the reflected distance-measuring light from the object to be measured, a deflection optical element that rotates vertically via a hollow vertical rotation axis, a vertical rotation drive unit that rotates the deflection optical element vertically, a base unit on which the deflection optical element is mounted, a horizontal rotation drive unit that rotates the base unit horizontally, an imaging unit that can capture an image of the object to be measured based on external light that has passed through the vertical rotation axis, and an arithmetic and control unit that calculates the distance to the object to be measured based on the result of reception of the reflected distance-measuring light by the light-receiving unit, wherein the distance measurement unit and the imaging unit are positioned opposite each other across the deflection optical element, the deflection optical element has two reflective surfaces that reflect the distance-measuring light, the reflected distance-measuring light, and the external light at right angles, and the arithmetic and control unit is configured to simultaneously perform distance measurement via one of the reflective surfaces and imaging via the other reflective surface.

[0007] The present invention also relates to a surveying instrument configured so that the distance measurement unit and the imaging unit are positioned so that the point cloud acquisition origin of the distance measurement unit and the entrance pupil position of the imaging unit coincide or approximately coincide.

[0008] The present invention also relates to a surveying instrument configured so that the distance measuring section further comprises a beam splitter that transmits the distance measuring light and reflects the reflected distance measuring light.

[0009] The present invention also relates to a surveying instrument that further has a second concave lens that reduces the diameter of the external light, and is configured to expand the imaging range of the imaging unit via the second concave lens.

[0010] The present invention also relates to a surveying instrument that further has a first concave lens that expands the diameter of the distance measuring light, and is configured to expand the measurement range of the distance measuring unit via the first concave lens.

[0011] The present invention also relates to a surveying instrument in which the first concave lens and the second concave lens are each arranged closer to the object to be measured than the deflection optical element and are configured to rotate integrally with the deflection optical element.

[0012] The present invention also relates to a surveying instrument in which the first concave lens and the second concave lens are each disposed closer to the light receiving side than the deflection optical member.

[0013] The present invention also relates to a surveying instrument in which the first concave lens and the second concave lens are configured to rotate integrally with the deflection optical member.

[0014] The present invention also relates to a surveying instrument in which the distance measurement unit is a two-dimensional distance measurement sensor capable of acquiring distance measurement data in a planar manner.

[0015] The present invention also relates to a surveying instrument configured so that the distance measuring sensor is a flash lidar, and the light projecting unit has at least one light emitting element that emits the distance measuring light.

[0016] The present invention also relates to a surveying instrument, wherein the light projecting unit further includes an MEMS mirror capable of deflecting the distance measuring light in two axial directions.

[0017] The present invention also relates to a surveying instrument in which the deflection optical element is a quadrangular prism formed by joining two triangular prisms, and reflective surfaces are formed on the front and back surfaces of the joined surface of the quadrangular prism.

[0018] The present invention also relates to a surveying instrument in which the deflection optical member is a triangular prism in the shape of a right-angled isosceles triangle, and a reflecting surface is formed on each of the front and back surfaces of the long sides of the triangular prism.

[0019] The present invention also relates to a surveying instrument in which the deflecting optical member is a plate-like mirror, and reflective surfaces are formed on both the front and back surfaces of the mirror.

[0020] Furthermore, the present invention relates to a surveying instrument configured such that the base portion has a recess formed therein in which the deflection optical element is housed, and the edge of the recess is tapered to form a tapered portion. [Effects of the Invention]

[0021] According to the present invention, the distance measuring device includes a light projecting unit that emits distance measuring light and a light receiving unit that receives the reflected distance measuring light from an object to be measured, a deflection optical member that is rotated in a vertical direction via a hollow vertical rotation shaft, a vertical rotation drive unit that rotates the deflection optical member in the vertical direction, a base unit on which the deflection optical member is provided, a horizontal rotation drive unit that rotates the base unit in a horizontal direction, an imaging unit that can capture an image of the object to be measured based on external light that has passed through the vertical rotation shaft, and a calculation control unit that calculates the distance to the object to be measured based on the result of reception of the reflected distance measuring light by the light receiving unit. The distance measurement unit and the imaging unit are arranged at positions facing each other with the deflection optical element in between, and the deflection optical element has two reflective surfaces that reflect the distance measurement light, the reflected distance measurement light, and the external light at right angles, and the calculation control unit is configured to simultaneously perform distance measurement via one of the reflective surfaces and imaging via the other reflective surface. This makes it possible to simultaneously perform measurement and imaging, thereby shortening the measurement time and eliminating or reducing the parallax between the distance measurement unit and the imaging unit, thereby providing the excellent effect of improving the coloring accuracy of the point cloud. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a front cross-sectional view showing a surveying instrument according to a first embodiment. [Figure 2] 1 is a cross-sectional plan view showing a surveying instrument according to a first embodiment. [Figure 3] FIG. 10 is an explanatory diagram showing the optical systems of a distance measurement unit and an imaging unit according to a second embodiment. [Figure 4] FIG. 10A is an explanatory diagram showing the optical system of the distance measurement unit and the imaging unit according to the third embodiment, and FIG. 10B is a view taken along the arrow A in FIG. [Figure 5] FIG. 10(A) is an explanatory diagram showing the optical system of the distance measurement unit and the imaging unit according to a modified example of the third embodiment, and FIG. 10(B) is a view taken along the arrow B in FIG. [Figure 6] FIG. 10(A) is an explanatory diagram showing the optical system of the distance measurement unit and the imaging unit according to the fourth embodiment, and FIG. 10(B) is a view taken along the arrow C in FIG. [Figure 7]FIG. 10(A) is an explanatory diagram showing the optical system of the distance measurement unit and the imaging unit according to the fifth embodiment, and FIG. 10(B) is a view taken along the arrow D in FIG. [Figure 8] FIG. 10(A) is an explanatory diagram showing the optical system of the distance measurement unit and the imaging unit according to the sixth embodiment, and FIG. 10(B) is a view taken along the arrow E in FIG. [Figure 9] FIG. 13 is an explanatory diagram showing the optical systems of a distance measurement unit and an imaging unit according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0024] First, a surveying instrument according to a first embodiment of the present invention will be described with reference to FIGS.

[0025] The surveying instrument 1 is, for example, a laser scanner, and is composed of a leveling unit 2 attached to a tripod (not shown), and a surveying instrument main body 3 attached to the leveling unit 2.

[0026] The leveling unit 2 has a leveling screw 10, and the leveling screw 10 is used to level the surveying instrument main body 3 horizontally.

[0027] The surveying instrument main body 3 is equipped with (contains) a fixed section 4, a base section 5, a horizontal rotation shaft 6, a horizontal rotation bearing 7, a horizontal rotation motor 8 as a horizontal rotation drive section, a horizontal angle encoder 9 as a horizontal angle detector, a vertical rotation shaft 11, a vertical rotation bearing 12, a vertical rotation motor 13 as a vertical rotation drive section, a vertical angle encoder 14 as a vertical angle detector, a rotation section 15, an operation panel 16 that serves both as an operation section and a display section, a calculation control section 17, a memory section 18, a distance measurement section 19, an imaging section 21, etc. The calculation control section 17 may be a CPU specialized for this instrument or a general-purpose CPU.

[0028] The horizontal rotation bearing 7 is fixed to the fixed part 4. The horizontal rotation shaft 6 has a vertical axis 6a, and the horizontal rotation shaft 6 is rotatably supported by the horizontal rotation bearing 7. In addition, the base frame part 5 is supported by the horizontal rotation shaft 6, and the base frame part 5 rotates integrally with the horizontal rotation shaft 6 in the horizontal direction.

[0029] The horizontal rotation motor 8 is provided between the horizontal rotation bearing 7 and the base frame 5, and the horizontal rotation motor 8 is controlled by the arithmetic and control unit 17. The arithmetic and control unit 17 causes the horizontal rotation motor 8 to rotate the base frame 5 about the axis 6a.

[0030] The relative rotation angle of the base unit 5 with respect to the fixed unit 4 is detected by the horizontal angle encoder 9. A detection signal from the horizontal angle encoder 9 is input to the arithmetic and control unit 17, which calculates horizontal angle data. The arithmetic and control unit 17 performs feedback control on the horizontal rotation motor 8 based on the horizontal angle data.

[0031] The base 5 is provided with the vertical rotation shaft 11 having a horizontal axis 11a. The vertical rotation shaft 11 is rotatable via the vertical rotation bearing 12. The intersection of the axis 6a and the axis 11a is the emission position of the distance measuring light, and is also the mechanical center of the surveying device main body 3, i.e., the origin of the coordinate system (point cloud acquisition origin).

[0032] A recess 22 is formed in the base frame portion 5. The vertical rotation shaft 11 is hollow, and one end of the vertical rotation shaft 11 extends into the recess 22. The rotating portion 15 is fixed to the one end of the vertical rotation shaft 11, and the rotating portion 15 is housed in the recess 22 and rotates integrally with the vertical rotation shaft 11.

[0033] Furthermore, tapered portions 24 are formed on the edges of the upper, front, and rear sides of the recess 22. The tapered portions 24 are formed on both sides of the rotating unit 15, and are configured so as not to obstruct the measurement range of the distance measurement unit 19 or the imaging range of the imaging unit 21. The angle of the tapered portions 24 is designed appropriately depending on the angle of view of the distance measurement unit 19 and the imaging unit 21.

[0034] The rotating unit 15 has a reflecting prism 25 as a deflecting optical element and two concave lenses 26a, 26b as wide-angle optical elements. The reflecting prism 25 is a substantially cubic square prism formed by joining two triangular prisms, and the joining surfaces of each triangular prism serve as reflecting surfaces. The reflecting surfaces are formed on the front and back surfaces of the joining surfaces, and the reflecting prism 25 has two reflecting surfaces 25a, 25b.

[0035] The concave lenses 26a and 26b are each parallel to the axis 11a and are provided adjacent to the surface of the reflecting prism 25 that faces the reflecting surfaces 25a and 25b. That is, the concave lenses 26a and 26b are arranged closer to the object to be measured than the reflecting prism 25. The concave lenses 26a and 26b are concave lenses whose surfaces facing the reflecting prism 25 are concave. Therefore, the reflecting surface 25a on the front side faces the first concave lens 26a, and the reflecting surface 25b on the back side faces the second concave lens 26b.

[0036] The concave lenses 26a and 26b may be a single lens or a lens group made up of a combination of multiple lenses. The first concave lens 26a and the second concave lens 26b have the same focal length and are arranged so that their focal positions coincide with each other.

[0037] The vertical angle encoder 14 is provided at the other end of the vertical rotation shaft 11. The imaging unit 21 is provided inside the vertical rotation shaft 11. The optical axis of the imaging unit 21 coincides with the axis center 11a, and the position at which the imaging unit 21 is provided is set according to the focal length of the imaging unit 21. For example, when using an imaging unit 21 with a long focal length, the imaging unit 21 is provided at a position away from the other end of the vertical rotation shaft 11, i.e., outside the vertical rotation shaft 11.

[0038] Furthermore, the distance measurement unit 19 is provided on the opposite side of the imaging unit 21 with the reflecting prism 25 in between. The distance measurement unit 19 is, for example, a Flash LiDAR (Light Detection And Ranging) that can acquire distance measurement data in a planar manner, and has a light projecting unit 28 that emits distance measurement light 27 and a light receiving unit 31 that receives reflected distance measurement light 29 reflected by the object to be measured. Note that other two-dimensional sensors such as a TOF camera may also be used as the distance measurement unit 19.

[0039] The vertical rotation motor 13 is provided on the vertical rotation shaft 11, and the vertical rotation motor 13 is controlled by the arithmetic and control unit 17. The arithmetic and control unit 17 rotates the vertical rotation shaft 11 using the vertical rotation motor 13, and the rotation unit 15, i.e., the reflecting prism 25 and the concave lenses 26a, 26b, rotates around the axis 11a.

[0040] The rotation angle of the reflecting prism 25 is detected by the vertical angle encoder 14, and the detection signal is input to the calculation control unit 17. The calculation control unit 17 calculates vertical angle data of the rotating unit 15 based on the detection signal, and performs feedback control on the vertical rotation motor 13 based on the vertical angle data.

[0041] The horizontal angle data, vertical angle data, and measurement results calculated by the calculation control unit 17 are stored in the storage unit 18. Various storage means can be used for the storage unit 18, such as a hard disk drive (HDD) as a magnetic storage device, a CD or DVD as an optical storage device, a memory card as a semiconductor storage device, a USB memory, etc. The storage unit 18 may be detachable from the base unit 5, or may be capable of transmitting data to an external storage device or external data processing device via a communication means (not shown).

[0042] The storage unit 18 stores various programs such as a sequence program for controlling distance measurement operation, a calculation program for calculating distance by distance measurement operation, a calculation program for calculating an angle based on horizontal angle data and vertical angle data, a program for calculating three-dimensional coordinates of a desired measurement point based on distance and angle, an imaging program for controlling the imaging operation by the imaging unit 21, a point cloud data creation program for creating three-dimensional point cloud data of a full 360° circumference based on measurement (distance measurement and angle measurement) results, a coloring program for creating colored point cloud data based on point cloud data and images captured by the imaging unit 21, and a three-dimensional coordinate assignment program for assigning three-dimensional coordinates to each pixel of the images captured by the imaging unit 21 based on the point cloud data. Furthermore, various processes are performed by the calculation control unit 17 executing the various programs.

[0043] The operation panel 16 is, for example, a touch panel, and serves as both an operation unit for giving distance measurement instructions and changing measurement conditions, such as the amount of overlap between adjacent images, and a display unit for displaying distance measurement results and images, etc.

[0044] Next, the distance measurement unit 19 will be described. The light-projecting unit 28 of the distance measurement unit 19 has a light-projecting optical axis 32. The light-projecting unit 28 has, in order from the light-emitting side, a light-emitting unit provided on the light-projecting optical axis 32, a beam splitter 34, the reflecting prism 25 provided on the transmitted optical axis of the beam splitter 34, and the first concave lens 26a provided on the reflected optical axis of the reflecting prism 25.

[0045] In this embodiment, the light projection optical axis 32, the light projection optical axis 32 that has passed through the beam splitter 34, and the light projection optical axis 32 that has been reflected by the reflecting prism 25 are collectively referred to as the light projection optical axis 32. In this embodiment, the optical axis that passes through the beam splitter 34 and coincides with a light reception optical axis 35 (described later) is referred to as the light projection optical axis 32.

[0046] The light emitting unit is composed of one light emitting element 33, and the light emitting element 33 is, for example, a laser diode (LD) that emits near-infrared light of a predetermined wavelength at a predetermined divergence angle as the distance measuring light 27. The light emitting element 33 may be arranged so that the optical axis of the distance measuring light 27 coincides with the light projection optical axis 32, or so that the optical axis of the distance measuring light 27 is parallel to the light projection optical axis 32 and the distance between the optical axes is a known distance.

[0047] The beam splitter 34 has optical properties of transmitting the distance measuring light 27 and reflecting the reflected distance measuring light 29, and the transmitted optical axis of the beam splitter 34 coincides or approximately coincides with the axis 11a.

[0048] The reflecting surface 25a reflects the distance measuring light 27 at a right angle, and the first concave lens 26a expands the diameter of the distance measuring light 27 so that it has a predetermined divergence angle (measurement range).

[0049] The first concave lens 26a has optical characteristics such that the focal position (entrance pupil position 20) when receiving reflected distance measuring light 29 coincides or approximately coincides with the mechanical center (point cloud acquisition origin 23) of the surveying device main body 3. In this embodiment, the spread angle of the first concave lens 26a is 75°, and the distance measuring unit 19 can measure within a range of 75° x 75°.

[0050] Increasing the spread angle of the distance measuring light 27 widens the measurement range, but reduces the number of measurement results (point cloud density) obtained, and shortens the measurable distance. On the other hand, decreasing the spread angle of the distance measuring light 27 narrows the measurement range, but increases the number of measurement results (point cloud density), and lengthens the measurable distance. Therefore, the spread angle of the distance measuring light 27 (the optical characteristics of the first concave lens 26a) is appropriately designed within the range of 20° to 180° depending on the distance to the measurement object and the application. The angle of the tapered portion 24 is also appropriately designed in accordance with the optical characteristics of the first concave lens 26a and the second concave lens 26b (described later).

[0051] The light receiving unit 31 has a light receiving optical axis 35. The light receiving unit 31 also has, in order from the light receiving side, a light receiving sensor 36 provided on the light receiving optical axis 35, a light receiving lens group 37, the beam splitter 34, the reflecting prism 25 provided on the reflected optical axis of the beam splitter 34, and the first concave lens 26a provided on the reflected optical axis of the reflecting prism 25.

[0052] In this embodiment, the receiving optical axis 35, the receiving optical axis 35 reflected by the beam splitter 34, and the receiving optical axis 35 reflected by the reflecting prism 25 are collectively referred to as the receiving optical axis 35.

[0053] Furthermore, a filter for removing external light, such as a band-pass filter, may be separately provided in the optical path of the light receiving unit 31. By providing a band-pass filter, external light (background light) can be prevented from being received by the light receiving sensor 36 together with the reflected distance measuring light 29.

[0054] The light receiving sensor 36 is, for example, a two-dimensional LiDAR sensor (ToF sensor) having an imaging element made up of a large number of pixels, and is configured so that each light receiving element receives the reflected distance measurement light 29 and each light receiving element emits a light receiving signal. The light receiving signal output by each element includes position information on the light receiving sensor 36, making it possible to identify the position of each light receiving element within the light receiving sensor 36. The light receiving sensor 36 may also be configured by arranging a plurality of single-element sensors.

[0055] The light receiving lens group 37 is composed of a plurality of concave and convex lenses, and is configured to make the reflected distance measuring light 29 reflected by the beam splitter 34 incident on the light receiving sensor 36 at a predetermined angle of incidence.

[0056] Next, we will explain the imaging unit 21. The imaging unit 21 has an imaging optical axis 38. The imaging unit 21 also has, in order from the light receiving side, an imaging element 39 provided on the imaging optical axis 38, an imaging lens group 41, the reflecting prism 25, and the second concave lens 26b provided on the reflected optical axis of the reflecting prism 25.

[0057] In this embodiment, the imaging optical axis 38 and the optical axis that is incident on the reflecting prism 25 and reflected so as to coincide with the imaging optical axis 38 are collectively referred to as the imaging optical axis 38. An IR cut filter for removing infrared and near-infrared wavelengths may be provided in the optical path of the imaging unit 21. By providing an IR cut filter, it is possible to prevent infrared or near-infrared light from being received by the imaging element 39 together with external light 42.

[0058] The imaging element 39 is a CCD or CMOS sensor that is a collection of pixels, and the position of each pixel can be specified on the imaging element 39. For example, each pixel has pixel coordinates with the center of the imaging element 39 (the imaging optical axis 38) as the origin, and the position on the imaging element 39 is specified by the pixel coordinates.

[0059] The imaging lens group 41 is composed of a plurality of concave and convex lenses, and is configured to receive the external light 42 reflected by the reflecting surface 25b at a predetermined angle of incidence onto the imaging element 39.

[0060] The reflecting surface 25b reflects at a right angle the external light 42 incident along the imaging optical axis 38. The second concave lens 26b collects the external light 42 within a predetermined angular range and makes it incident on the reflecting prism 25.

[0061] The second concave lens 26b has the same focal length as the first concave lens 26a, and the entrance pupil position 20 when receiving the external light 42 coincides or substantially coincides with the mechanical center of the surveying device main body 3 and the point cloud acquisition origin 23 of the distance measurement unit 19. For example, the angle of view of the imaging unit 21 is appropriately set in the range of 20° to 180° so as to be the same as or substantially the same as the measurement range of the distance measurement unit 19. In this embodiment, the angle of view of the second concave lens 26b is 75°, and the imaging unit 21 has an imaging range of 75° x 75°.

[0062] The distance measurement unit 19 and the imaging unit 21 are each controlled by the arithmetic and control unit 17 .

[0063] First, the operation of the distance measurement unit 19 will be described. The light-emitting element 33 emits the distance measurement light 27 on or parallel to the light-projecting optical axis 32. The distance measurement light 27 is emitted, for example, in pulses, passes through the beam splitter 34, enters the reflecting prism 25, and is reflected at a right angle by the reflecting surface 25a. The distance measurement light 27 reflected by the reflecting surface 25a is expanded by the first concave lens 26a to a predetermined spread angle and is then irradiated onto the measurement object. The distance measurement light 27 is irradiated onto a plane parallel to the axis 11a, and as the reflecting prism 25 rotates around the axis 11a, the distance measurement light 27 is irradiated all around the axis 11a.

[0064] The reflected distance measuring light 29 reflected by the object to be measured is reduced in diameter by the first concave lens 26a, enters the reflecting prism 25, and is reflected at a right angle by the reflecting surface 25a. The reflected distance measuring light 29 reflected by the reflecting surface 25a is reflected at a right angle by the beam splitter 34, passes through the light receiving lens group 37, and is received by the light receiving sensor 36.

[0065] The light receiving optical axis 35 of the reflected distance measuring light 29 reflected by the reflecting surface 25a is coaxial with the light projecting optical axis 32 transmitted through the beam splitter 34. That is, the light projecting optical axis 32 and the light receiving optical axis 35 coincide with the axis center 11a.

[0066] The calculation control unit 17 measures distance for each pulse of the distance measuring light 27 (time of flight) based on the time difference between the light emission timing of the light emitting element 33 and the light reception timing of the light receiving sensor 36 (i.e., the round trip time of the pulsed light) and the speed of light, and calculates the distance to the object to be measured for each element. That is, distance measurement is performed simultaneously by each element of the light receiving sensor 36 for each pulse, and multiple distance measurement results can be obtained.

[0067] Furthermore, by rotating the base unit 5 and the rotating unit 15 (the reflecting prism 25) at a constant speed while emitting the distance measuring light 27 at a predetermined pulse interval, the vertical rotation of the rotating unit 15 and the horizontal rotation of the base unit 5 cooperate to irradiate the distance measuring light 27 over a full 360° circumference. Furthermore, by detecting the vertical angle and horizontal angle for each pulse of light and for each element using the vertical angle encoder 14 and the horizontal angle encoder 9, vertical angle data and horizontal angle data can be acquired for each element. The vertical angle data, horizontal angle data, and distance measuring data for each element can be used to acquire the three-dimensional coordinates of the object to be measured and three-dimensional point cloud data corresponding to the object to be measured. The acquired point cloud data is stored in the memory unit 18.

[0068] The timing of light emission of the light emitting element 33, that is, the pulse interval, can be changed via the operation panel 16.

[0069] In parallel with the distance measurement operation, the external light 42 incident on the second concave lens 26b is condensed (reduced in diameter) and enters the reflecting prism 25, where it is reflected at a right angle by the reflecting surface 25b. The external light 42 reflected by the reflecting surface 25b passes through the hollow interior of the vertical rotation shaft 11, transmits through the imaging lens group 41, and is received by the imaging element 39, whereby an image centered on the imaging optical axis 38 is acquired. The acquired image is stored in the storage unit 18.

[0070] When measurement by the distance measurement unit 19 and image capture by the image capture unit 21 are completed, the horizontal rotation motor 8 and the vertical rotation motor 13 are driven. The horizontal rotation of the base unit 5 and the vertical rotation of the rotation unit 15 cooperate to move to the next position, where measurement and image capture are performed again, i.e., measurement is performed. The above process is repeated until measurement and image capture of the entire 360° circumference are completed. It is desirable to drive the horizontal rotation motor 8 and the vertical rotation motor 13 so that adjacent measurement results and images overlap within a predetermined range.

[0071] The calculation control unit 17 creates colored point cloud data or a coordinate-coded image having three-dimensional coordinates for each pixel based on the measurement results acquired by the distance measurement unit 19 and the image acquired by the imaging unit 21.

[0072] Here, the reflecting surfaces 25a and 25b are reflecting surfaces formed on the front and back of the joint surface of the reflecting prism 25, and the position of the intersection between the projection optical axis 32 (the receiving optical axis 35) and the reflecting surface 25a coincides or approximately coincides with the position of the intersection between the imaging optical axis 38 and the reflecting surface 25b.

[0073] Therefore, the measurement results and images acquired by the distance measurement unit 19 and the imaging unit 21 at the same time are measurement results and images that are 180° out of position, so by acquiring measurement results and images that are 180° out of position based on the detection results of the vertical angle encoder 14, the measurement range of the distance measurement unit 19 and the imaging range of the imaging unit 21 can be matched, and the positions of the measurement results and images can be matched.

[0074] As described above, in the first embodiment, the distance measurement unit 19 and the imaging unit 21 are arranged in symmetrical positions on either side of the reflecting prism 25, and measurement results and images at different positions 180° apart can be obtained simultaneously via the two reflecting surfaces 25a, 25b formed on the front and back of the reflecting prism 25.

[0075] Therefore, since there is no need to perform measurement and imaging separately at different times, the measurement time can be shortened.

[0076] Furthermore, the distance measurement unit 19 and the imaging unit 21 are arranged so that the point cloud acquisition origin 23 of the distance measurement unit 19 and the entrance pupil position 20 of the imaging unit 21 coincide or nearly coincide, so that the parallax between the distance measurement unit 19 and the imaging unit 21 can be eliminated or made extremely small.

[0077] Therefore, a wide range of the image acquired by the imaging unit 21 can be used for coloring the point cloud data acquired by the distance measurement unit 19, thereby improving the accuracy of coloring the point cloud data or the accuracy of assigning three-dimensional coordinates to each pixel of the 360° image. Also, the amount of overlap between adjacent images can be reduced, thereby shortening the measurement time.

[0078] Furthermore, since the distance measurement unit 19 and the imaging unit 21 each have the concave lenses 26a, 26b, they can measure and image a range greater than the spread angle of the light-emitting element 33, so that the number of measurements and images required to obtain point cloud data for the entire circumference can be reduced, thereby shortening the measurement time.

[0079] Furthermore, since the tapered portion 24 is formed on the edge of the recess 22 of the base portion 5, it is possible to prevent the base portion 5 from blocking the distance measurement light 27 irradiated from the first concave lens 26a and the external light 42 incident on the second concave lens 26b.

[0080] Next, a second embodiment of the present invention will be described with reference to Fig. 3. In Fig. 3, the same components as those in Fig. 2 are given the same reference numerals, and their description will be omitted.

[0081] In the second embodiment, the rotating portion 15 has a reflecting mirror 45 as a deflecting optical member, and reflecting surfaces 45a and 45b are formed on the front and back surfaces of the reflecting mirror 45, respectively.

[0082] Also, the imaging optical axis 38 of the imaging unit 21 coincides with the axis 11a, and the light projection optical axis 32 (light reception optical axis 35) of the distance measurement unit 19 is offset from the imaging optical axis 38 by the thickness of the reflecting mirror 45, for example, by about 1 mm to 3 mm. The other configurations are the same as those of the first embodiment.

[0083] In the second embodiment, the point cloud acquisition origin 23 of the distance measurement unit 19 and the entrance pupil position 20 of the imaging unit 21 are shifted by the thickness of the reflecting mirror 45. However, since the thickness of the reflecting mirror 45 is about 1 mm to 3 mm and the amount of shift is small, the point cloud acquisition origin 23 and the entrance pupil position 20 can be considered to substantially coincide with each other.

[0084] Therefore, the parallax between the distance measurement unit 19 and the imaging unit 21 can be reduced, and the accuracy of coloring point cloud data or the accuracy of assigning three-dimensional coordinates to each pixel of the panoramic image can be improved.

[0085] In the second embodiment, the deflection optical member is the lightweight and inexpensive reflecting mirror 45. Therefore, the weight of the rotating part 15 can be reduced, the wobble of the vertical rotation axis 11 (see FIG. 1) can be suppressed, and the manufacturing cost of the surveying device main body 3 (see FIG. 1) can be reduced.

[0086] Next, a third embodiment of the present invention will be described with reference to Figures 4(A) and 4(B). In Figures 4(A) and 4(B), the same components as those in Figure 2 are designated by the same reference numerals, and their description will be omitted.

[0087] In the third embodiment, the light emitting section of the light projecting section 28 is made up of two light emitting elements 46 (light emitting elements 46a, 46b). The other configurations are the same as those of the first embodiment.

[0088] The light-emitting elements 46a and 46b each emit a distance measurement light 27. The optical axis of the distance measurement light 27 is parallel to the light projection optical axis 32 and is disposed symmetrically with respect to the light projection optical axis 32. The distance between the optical axis of each distance measurement light 27 and the light projection optical axis 32 is known.

[0089] In the third embodiment, the light emitting unit is made up of the two light emitting elements 46a, 46b, and the distance measuring light 27 is also emitted from each of the light emitting elements 46a, 46b. Therefore, the amount of light of the distance measuring light 27 can be increased, so that the reach of the distance measuring light 27 can be increased and a sufficient amount of light of the reflected distance measuring light 29 can be obtained even when the measurement range is widened.

[0090] Furthermore, since the point cloud acquisition origin 23 of the distance measurement unit 19 and the entrance pupil position 20 of the imaging unit 21 can be made to coincide or approximately coincide, the parallax between the distance measurement unit 19 and the imaging unit 21 can be eliminated or approximately eliminated, thereby improving the accuracy of coloring the point cloud data or the accuracy of assigning three-dimensional coordinates to each pixel of the panoramic image.

[0091] 5(A) and 5(B) show a modification of the third embodiment, in which the light receiving unit 31 does not have a beam splitter 34, and the reflected distance measuring light 29 reflected by the reflecting surface 25a is directly incident on the light receiving sensor 36 via the light receiving lens group 37.

[0092] The light-emitting elements 46a and 46b are disposed symmetrically with respect to the light-projecting optical axis 32, sandwiching the light-receiving lens group 37 or the light-receiving sensor 36 therebetween. It is desirable that the light-emitting elements 46a and 46b are disposed so that the distance measurement light 27 is not received by the light-receiving lens group 37.

[0093] In the above-described modified example, the amount of light of the distance measuring light 27 can be increased, so that the reach of the distance measuring light 27 can be increased, the measurable distance can be extended, and a sufficient amount of light can be received from the reflected distance measuring light 29 even when the measurement range is expanded.

[0094] Next, a fourth embodiment of the present invention will be described with reference to Figures 6(A) and 6(B). In Figures 6(A) and 6(B), the same components as those in Figures 4(A) and 4(B) are designated by the same reference numerals, and their description will be omitted.

[0095] In the fourth embodiment, a reflecting prism 47 serving as a deflecting optical member is a triangular prism in the shape of a right-angled isosceles triangle, and reflecting surfaces 47a and 47b are formed on the front and back surfaces, respectively.

[0096] Also, the first concave lens 48a is disposed between the beam splitter 34 and the reflecting prism 47, and the second concave lens 48b is disposed between the imaging lens group 41 and the reflecting prism 47. That is, the first concave lens 48a and the second concave lens 48b are each disposed closer to the light receiving side than the reflecting prism 47. Also, the reflecting prism 47, the first concave lens 48a, and the second concave lens 48b form a rotating unit 15. The other configurations are the same as those of the third embodiment.

[0097] In the fourth embodiment, the first concave lens 48a is disposed closer to the light receiving sensor 36 than in the third embodiment, and the second concave lens 48b is disposed closer to the image pickup element 39. Therefore, the first concave lens 48a and the second concave lens 48b can be made smaller, which makes it possible to reduce the cost and the weight of the rotating unit 15.

[0098] Furthermore, since the reflecting prism 47 is a triangular prism, it can be made lighter in weight than when a square prism is used, and the weight of the rotating portion 15 can be further reduced.

[0099] In the fourth embodiment, the reflecting prism 47 is a triangular prism, but it may be a square prism as in the third embodiment. By using a square prism for the reflecting prism 47, both the reflected distance measuring light 29 and the external light 42 pass through the prism, and therefore the reflected distance measuring light 29 and the external light 42 can be deflected in the same manner.

[0100] Therefore, the point cloud acquisition origin 23 of the distance measurement unit 19 and the entrance pupil position 20 of the imaging unit 21 can be made to coincide or approximately coincide, and the parallax between the distance measurement unit 19 and the imaging unit 21 can be reduced.

[0101] Next, a fifth embodiment of the present invention will be described with reference to Figures 7(A) and 7(B). In Figures 7(A) and 7(B), the same components as those in Figures 6(A) and 6(B) are designated by the same reference numerals, and their description will be omitted.

[0102] In the fifth embodiment, the rotating unit 15 is composed of only a reflecting prism 47. A first concave lens 48a is fixedly provided between the beam splitter 34 and the reflecting prism 47, and a second concave lens 48b is fixedly provided between the imaging lens group 41 and the reflecting prism 47. In other words, the first concave lens 48a and the second concave lens 48b are configured so as not to rotate integrally with the reflecting prism 47. The other configurations are the same as those of the fourth embodiment.

[0103] In the fifth embodiment, the rotating part 15 is made up of only the reflecting prism 47, so that the weight of the rotating part 15 can be reduced and the wobble of the vertical rotating shaft 11 (see FIG. 1) can be suppressed.

[0104] Next, a sixth embodiment of the present invention will be described with reference to Figures 8(A) and 8(B). In Figures 8(A) and 8(B), the same components as those in Figures 7(A) and 7(B) are designated by the same reference numerals, and their description will be omitted.

[0105] In the sixth embodiment, the distance measurement unit 19 does not have a concave lens for expanding the measurement range, but the other configurations are the same as those of the fifth embodiment.

[0106] In the distance measurement unit 19 of the sixth embodiment, the concave lens, which is a transmission component commonly used in the light projecting unit 28 and the light receiving unit 31, is omitted.

[0107] Therefore, the occurrence of return light of the distance measurement light 27 reflected by the concave lens can be suppressed, thereby suppressing the occurrence of distance measurement errors caused by the return light being received by the light receiving sensor 36, thereby improving distance measurement accuracy.

[0108] Next, a seventh embodiment of the present invention will be described with reference to Fig. 9. In Fig. 9, the same components as those in Fig. 2 are given the same reference numerals, and their description will be omitted.

[0109] In the seventh embodiment, the light projecting unit 28 of the distance measuring unit 19 is composed of, in order from the light emitting side, a light emitting element 33 provided on the light projecting optical axis, a collimator lens 51, an MEMS mirror 53, a beam splitter 34, the reflecting prism 25 provided on the transmitted optical axis of the beam splitter 34, and the first concave lens 26a provided on the reflected optical axis of the reflecting prism 25. The other configurations are the same as those of the first embodiment.

[0110] The collimator lens 51 is configured to collimate the distance measurement light 27 emitted from the light emitting element 33. The MEMS mirror 53 is a two-axis MEMS (Micro Electro Mechanical System) mirror, and its tilt angle can be changed in two orthogonal axis directions.

[0111] By driving the MEMS mirror 53, the distance measurement light 27 can be scanned in two axial directions (two-dimensionally) within a predetermined range without driving the horizontal rotation motor 8 (see Figure 1) and the vertical rotation motor 13 (see Figure 1).

[0112] In the seventh embodiment, the distance measuring light 27 can be scanned two-dimensionally by driving the MEMS mirror 53, so that even if the irradiation range of the distance measuring light 27 is narrower than the shooting range of the imaging unit 21, a measurement range equivalent to the shooting range can be measured.

[0113] Therefore, the spread angle of the distance measuring light 27 emitted from the first concave lens 26a can be reduced and the amount of reflected distance measuring light 29 received can be increased, thereby extending the reach of the distance measuring light 27 and increasing the measurable distance.

[0114] Furthermore, by reducing the spread angle of the distance measuring light 27, the density of the point cloud acquired by the distance measuring unit 19 can be increased.

[0115] In the seventh embodiment, the MEMS mirror 53 is a biaxial MEMS mirror, but it is also possible to provide two uniaxial MEMS mirrors so that the distance measuring light 27 can be scanned in two axial directions.

[0116] Furthermore, it goes without saying that the deflection optical members, wide-angle optical members, light emitting sections, etc. in the first to seventh embodiments can be appropriately combined in combinations other than those in the above-mentioned embodiments. [Explanation of symbols]

[0117] 1 Surveying equipment 3 Surveying device body 17 Calculation control unit 19 Distance measurement unit 21 Imaging unit 25 Reflecting Prism 27 Ranging light 29 Reflected ranging light 42 Plenty of light

Claims

1. a deflection optical element that is rotated vertically via a hollow vertical rotation axis; a vertical rotation drive unit that rotates the deflection optical element vertically; a base unit on which the deflection optical element is mounted; a horizontal rotation drive unit that rotates the base unit horizontally; an imaging unit that can capture an image of the object to be measured based on external light that has passed through the vertical rotation axis; and an arithmetic control unit that calculates the distance to the object to be measured based on the result of reception of the reflected distance measuring light by the light receiving unit, wherein the distance measuring unit and the imaging unit are positioned opposite each other across the deflection optical element, and the deflection optical element has two reflective surfaces that reflect the distance measuring light, the reflected distance measuring light, and the external light at right angles, and the arithmetic control unit is configured to simultaneously perform distance measuring via one of the reflective surfaces and imaging via the other reflective surface.

2. 2. The surveying instrument according to claim 1, wherein the distance measurement unit and the imaging unit are arranged so that the point cloud acquisition origin of the distance measurement unit and the entrance pupil position of the imaging unit coincide or approximately coincide.

3. 3. The surveying instrument according to claim 2, wherein the distance measuring unit further comprises a beam splitter that transmits the distance measuring light and reflects the reflected distance measuring light.

4. 3. The surveying instrument according to claim 2, further comprising a second concave lens for reducing the diameter of the external light, and configured to expand the imaging range of the imaging unit via the second concave lens.

5. 5. A surveying instrument according to claim 4, further comprising a first concave lens for expanding the diameter of the distance measuring light, and configured to expand the measurement range of the distance measuring unit via the first concave lens.

6. 6. The surveying instrument according to claim 5, wherein the first concave lens and the second concave lens are arranged closer to the object to be measured than the deflection optical element and are configured to rotate integrally with the deflection optical element.

7. 6. The surveying instrument according to claim 5, wherein the first concave lens and the second concave lens are disposed closer to the light receiving side than the deflection optical member.

8. 8. A surveying instrument according to claim 7, wherein the first concave lens and the second concave lens are configured to rotate integrally with the deflection optical member.

9. 2. The surveying instrument according to claim 1, wherein the distance measurement unit is a two-dimensional distance measurement sensor capable of acquiring distance measurement data in a plane.

10. 10. The surveying instrument according to claim 9, wherein the distance measuring sensor is a flash lidar, and the light projecting unit has at least one light emitting element that emits the distance measuring light.

11. The surveying instrument according to claim 2 , wherein the light projecting unit further comprises a MEMS mirror capable of deflecting the distance measuring light in two axial directions.

12. The surveying instrument according to any one of claims 1 to 11, wherein the deflection optical element is a quadrangular prism formed by joining two triangular prisms, and a reflective surface is formed on each of the front and back surfaces of the joined surface of the quadrangular prism.

13. The surveying instrument according to any one of claims 1 to 11, wherein the deflection optical element is a triangular prism in the shape of a right-angled isosceles triangle, and a reflective surface is formed on the front and back surfaces of the long sides of the triangular prism.

14. 12. The surveying instrument according to claim 1, wherein the deflection optical member is a plate-shaped mirror, and a reflecting surface is formed on each of the front and rear surfaces of the mirror.

15. A surveying instrument according to any one of claims 1 to 11, wherein the support portion is formed with a recess in which the deflection optical element is housed, and the edge of the recess is tapered to form a tapered portion by cutting out.

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