JP2023050683A - Survey instrument - Google Patents

Abstract

To provide a survey instrument which offers reduced errors in ranging results by making a ranging light beam profile uniform.SOLUTION: A survey instrument is provided, comprising a ranging light emission unit having a light-emitting unit for emitting ranging light toward a survey target object and a one-dimensional diffusion optical element for diffusing the ranging light in a one-dimensional direction, a ranging light receiving unit having a light receiving element for receiving reflected ranging light from the survey target object, and an arithmetic control unit 17 configured to control the light-emitting unit and compute the distance to the survey target object based on a result of reception of the reflected ranging light by the light receiving element. The light-emitting unit has at least two light-emitting elements that are stacked in one direction, and the one-dimensional diffusion optical element is configured to diffuse the ranging light in the lamination direction of the light-emitting elements.SELECTED DRAWING: Figure 1

Description

The present invention relates to a surveying instrument capable of acquiring three-dimensional coordinates of an object to be measured.

Surveying devices such as laser scanners and total stations are light wave distance measuring devices that detect the distance to an object by prism distance measurement using a retroreflective prism as the object to be measured, or by non-prism distance measurement that does not use a reflecting prism. have.

2. Description of the Related Art As a light source for a surveying instrument, there is a multi-stack laser in which a plurality of light emitting elements, such as laser diodes, are stacked to emit light simultaneously. A multi-stack laser increases the amount of light emitted from a plurality of light-emitting elements to increase the distance that can be measured.

However, even if each light-emitting element is controlled to emit light at the same time, the timing of light emission may be shifted due to manufacturing errors or the like. In addition, due to this deviation, a difference of about ±10 mm, for example, may occur in the distance measurement value for each light emitting element.

On the other hand, in the case of prism ranging using a measuring object such as a reflecting prism having retroreflectivity, the ranging light is reflected while maintaining the beam profile (intensity distribution) of the ranging light. Therefore, when performing prism measurement using a multi-stack laser as a light source, there is a risk that an error will occur in the distance measurement result depending on which part of the distance measurement light is reflected, that is, the light of which light emitting element is reflected.

Japanese Patent Application Laid-Open No. 2021-25993 JP 2018-91764 A

SUMMARY OF THE INVENTION The present invention provides a surveying apparatus that uniformizes the beam profile of distance measuring light and reduces errors in distance measurement results.

The present invention comprises a distance measuring light emitting part having a light emitting part for emitting distance measuring light to an object to be measured, a one-dimensional diffusion optical element for diffusing the distance measuring light in one dimension, and a distance measuring light from the object to be measured. A distance measuring light receiving unit having a light receiving element for receiving reflected distance measuring light, and an operation for controlling the light emitting unit and calculating the distance to the object to be measured based on the result of receiving the reflected distance measuring light with respect to the light receiving element. a control unit, wherein the light emitting unit has at least two light emitting elements stacked in one direction, and the one-dimensional diffusion optical element is configured to diffuse the distance measuring light in the stacking direction of the light emitting elements. It relates to a surveying instrument.

In the present invention, the object to be measured is a corner cube having retroreflectivity, and the distance measuring light diffused by the one-dimensional diffusion optical element is an overlapping light emitted from each light emitting element. A surveying instrument configured to measure the corner cube at the overlapped portion.

Further, the present invention includes a mounting portion which is rotated horizontally about a horizontal rotation axis by a horizontal rotation motor, and a vertical rotation motor provided in the mounting portion which is vertically rotated about the vertical rotation axis. A scanning mirror that irradiates a corner cube and receives the reflected ranging light from the corner cube, a horizontal angle encoder that detects the horizontal angle of the mounting portion, and a vertical angle that detects the vertical angle of the scanning mirror. An encoder is further provided, and the arithmetic control unit determines the center-of-gravity position of the corner cube based on the amount of received light of the reflected distance measuring light, the horizontal angle, and the vertical angle when the corner cube is scanned with the distance measuring light. The present invention relates to a surveying instrument configured to calculate and measure the angle of the corner cube based on the position of the center of gravity.

Further, in the present invention, the arithmetic control unit determines whether or not the corner cube has been measured in the overlapping portion based on the amount of received light of the reflected distance measuring light, and it is determined that the distance has not been measured in the overlapping portion. The present invention relates to a surveying instrument configured to discard the results of distance measurement.

Further, according to the present invention, the arithmetic control unit calculates the center-of-gravity position of the corner cube based on the light amount distribution obtained when the corner-cube is scanned with the distance-measuring light, and calculates a preset threshold value from the center-of-gravity position. A surveying device configured to determine whether or not the corner cube has been measured in the overlapping portion based on whether or not it is positioned within the range, and to discard distance measurement results determined not to have been measured in the overlapping portion. It is related to

In the surveying apparatus according to the present invention, the distance measuring light emitting section further comprises a driving mechanism, and the driving mechanism inserts and removes the one-dimensional diffusion optical element with respect to the optical axis of the distance measuring light. It is related.

Further, the present invention relates to a surveying instrument, wherein the distance measuring light receiving section further includes a light receiving prism that causes the light receiving element to receive the reflected distance measuring light after internally reflecting the reflected distance measuring light a plurality of times.

According to the present invention, a distance measuring light emitting unit having a light emitting unit that emits distance measuring light to an object to be measured and a one-dimensional diffusion optical element that diffuses the distance measuring light in a one-dimensional direction; A distance measuring light receiving unit having a light receiving element for receiving the reflected distance measuring light from the distance measuring light, and the light emitting unit is controlled to calculate the distance to the object to be measured based on the result of receiving the reflected distance measuring light with respect to the light receiving element. The light emitting unit has at least two light emitting elements stacked in one direction, and the one-dimensional diffusion optical element diffuses the distance measuring light in the stacking direction of the light emitting elements. Since each distance measuring light is superimposed on each other, the beam profile of the distance measuring light can be made uniform, and a uniform distance measurement result can be obtained regardless of the number of laminated light emitting elements. effective.

1 is a front sectional view showing a surveying instrument according to an embodiment of the present invention; FIG. 3A and 3B are configuration diagrams showing a distance measuring unit according to an embodiment of the present invention; FIG. (A) is the beam profile of the ranging light when the one-dimensional diffusion optical element is not used, (B) is the beam profile of the ranging light when the one-dimensional diffusion optical element is used, and (C) is Profile cross-sectional intensity of each range-finding light at line A. (A) is an explanatory diagram showing the relationship between the distance measuring light and the corner cube when the one-dimensional diffusing optical element is not used, and (B) is an explanatory view showing the distance measuring light and the corner cube when the one-dimensional diffusing optical element is used. It is an explanatory diagram showing the relationship between. (A) is an explanatory diagram showing the case where a corner cube is scanned with distance measuring light when a one-dimensional diffusing optical element is not used, and (B) is a distribution diagram showing the relationship between the angle and the amount of received light at this time. be. (A) is an explanatory diagram showing the case where a corner cube is scanned with distance measuring light when a one-dimensional diffusion optical element is used, and (B) is a distribution diagram showing the relationship between the angle and the amount of received light at this time. be. FIG. 5 is a configuration diagram showing a distance measuring section according to a modification of the embodiment of the present invention; It is the profile cross-sectional intensity of each range-finding light according to the modified example of the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, referring to FIG. 1, a surveying instrument according to a first embodiment of the present invention will be described.

The surveying instrument 1 is, for example, a laser scanner, and comprises a leveling section 2 attached to a tripod (not shown) and a surveying instrument main body 3 attached to the leveling section 2 .

The leveling section 2 has a leveling screw 10, and the leveling of the surveying instrument main body 3 is performed by the leveling screw 10. As shown in FIG.

The surveying instrument main body 3 includes a fixed portion 4, a frame portion 5, a horizontal rotary shaft 6, a horizontal rotary bearing 7, a horizontal rotary motor 8 as a horizontal rotary drive portion, and a horizontal angle detector as a horizontal angle detector. An encoder 9, a vertical rotary shaft 11, a vertical rotary bearing 12, a vertical rotary motor 13 as a vertical rotation driving section, a vertical angle encoder 14 as a vertical angle detection section, a scanning mirror 15 as a vertical rotation section, It has an operation panel 16 that serves as both an operation unit and a display unit, an arithmetic control unit 17, a storage unit 18, a distance measurement unit 19, and the like. As the arithmetic control section 17, a CPU specialized for this apparatus or a general-purpose CPU is used.

The horizontal rotation bearing 7 is fixed to the fixed part 4 . The horizontal rotary shaft 6 has a vertical axis 6a, and is rotatably supported by the horizontal rotary bearing 7. As shown in FIG. Further, the frame portion 5 is supported by the horizontal rotation shaft 6 so that the frame portion 5 rotates integrally with the horizontal rotation shaft 6 in the horizontal direction.

The horizontal rotation motor 8 is provided between the horizontal rotation bearing 7 and the frame portion 5 , and the horizontal rotation motor 8 is controlled by the arithmetic control portion 17 . The calculation control unit 17 causes the horizontal rotation motor 8 to rotate the support unit 5 around the axis 6a.

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

Further, the mounting portion 5 is provided with the vertical rotary shaft 11 having a horizontal axis 11a. The vertical rotary shaft 11 is rotatable via the vertical rotary bearing 12 . The intersection of the axis 6a and the axis 11a is the emission position of the distance measuring light, and is the origin of the coordinate system of the surveying instrument main body 3.

A concave portion 22 is formed in the support portion 5 . One end of the vertical rotary shaft 11 extends into the recess 22 , and the scanning mirror 15 is fixed to the one end, and the scanning mirror 15 is accommodated in the recess 22 . Also, the vertical angle encoder 14 is provided at the other end of the vertical rotary shaft 11 .

The vertical rotary shaft 11 is provided with the vertical rotary motor 13 , and the vertical rotary motor 13 is controlled by the arithmetic control section 17 . The arithmetic control unit 17 rotates the vertical rotation shaft 11 by the vertical rotation motor 13, and the scanning mirror 15 is rotated around the axis 11a.

The rotation angle of the scanning mirror 15 is detected by the vertical angle encoder 14 and the detection signal is input to the arithmetic control section 17 . The arithmetic control unit 17 calculates vertical angle data of the scanning mirror 15 based on the detection signal, and performs feedback control for the vertical rotation motor 13 based on the vertical angle data.

Further, the horizontal angle data, vertical angle data and measurement results calculated by the arithmetic control unit 17 are stored in the storage unit 18 . As the storage section 18, various storage means such as an HDD as a magnetic storage device, a CD and a DVD as an optical storage device, a memory card as a semiconductor storage device, and a USB memory are used. The storage unit 18 may be detachable from the mounting unit 5, or may transmit data to an external storage device or an external data processing device via communication means (not shown).

The storage unit 18 stores a control program for controlling the driving of the light emitting elements of the light emitting unit, a sequence program for controlling the distance measurement operation, a calculation program for calculating the distance by the distance measurement operation, horizontal angle data and vertical angle data. Calculation program for calculating angle based on distance, program for calculating 3D coordinates of desired measurement point based on distance and angle, calculation program for calculating center of gravity of measurement object based on measurement result, received light intensity of reflected ranging light Various programs such as a control program for discarding distance measurement results having errors are stored. Further, various processes are executed by executing various programs by the arithmetic control unit 17 .

The operation panel 16 is, for example, a touch panel, and serves both as an operation unit for instructing distance measurement and for changing measurement conditions, such as measurement point intervals, and as a display unit for displaying distance measurement results, images, and the like.

Next, the distance measuring section 19 will be described with reference to FIGS. 2(A) and 2(B).

The distance measuring section 19 has a distance measuring light emitting section 23 and a distance measuring light receiving section 24 . The distance measuring light emitting portion 23 and the distance measuring light receiving portion 24 constitute a distance measuring portion.

The distance measuring light emitting section 23 has a distance measuring optical axis 38 . The distance measuring light emitting portion 23 includes a light emitting portion 25 provided on the distance measuring optical axis 38, a collimator lens 26, the beam shaping optical element 27, and the reflected optical axis of the beam shaping optical element 27. It has a one-dimensional diffusion optical element 28 provided thereon, a reflecting prism 29 as a deflecting member, and a fixing member 31 for fixing the reflecting prism 29 . Also, the scanning mirror 15 is provided on the distance measuring optical axis 38 reflected by the reflecting prism 29 . The fixing member 31 is made of a transparent material such as a glass plate. A window portion 32 made of a transparent material and rotating integrally with the scanning mirror 15 is provided on the reflecting optical axis of the scanning mirror 15 .

The collimator lens 26 , the beam shaping optical element 27 , the one-dimensional diffusion optical element 28 , the reflecting prism 29 and the like constitute a projection optical system 33 . In this embodiment, the distance measuring optical axis 38, the distance measuring optical axis 38 reflected by the beam shaping optical element 27, and the distance measuring optical axis 38 reflected by the reflecting prism 29 are collectively referred to. is defined as the distance measuring optical axis 38 .

Also, the distance measuring light receiving section 24 has a light receiving optical axis 39 . The distance measuring light receiving section 24 has a light receiving element 34 provided on the light receiving optical axis 39 and a light receiving prism 35, and is provided on the light receiving optical axis 39 reflected by the light receiving prism 35 and has a predetermined NA. has a light receiving lens 36 having a The light receiving prism 35 and the light receiving lens 36 constitute a light receiving optical system 37 . In this embodiment, the light receiving optical axis 39 and the reflected light axis reflected by the light receiving prism 35 are collectively referred to as the light receiving optical axis 39 .

The light emitting section 25 is a multi-stack laser light source in which a plurality of light emitting elements, such as laser diodes (LD) are stacked. The light-emitting unit 25 is composed of, for example, three stacked light-emitting elements. Laser beams are simultaneously emitted from each light-emitting element, and the synthesized pulsed light is emitted as distance measuring light 41 (described later). controlled to do so. The three light emitting elements simultaneously emit light to emit the synthesized distance measuring light 41, thereby securing the amount of light of the distance measuring light 41 emitted from the light emitting unit 25 and enabling long-distance measurement by the surveying device 1. and

The number of light emitting elements constituting the light emitting section 25 may be two, four or five. The distance to the light emitting element is appropriately set according to the assumed distance to the object to be measured.

The beam-shaping optical element 27 is, for example, a reflective or transmissive anamorphic prism. The distance measuring light 41 emitted from the light emitting unit 25 and collimated by the collimator lens 26 has an elliptical beam shape. It is configured to deflect at right angles while correcting to shape.

The one-dimensional diffusion optical element 28 is configured to diffuse the distance measuring light 41 deflected by the beam shaping optical element 27 in a predetermined direction (one-dimensional direction). In this embodiment, the direction in which the distance measuring light 41 is diffused by the one-dimensional diffusion optical element 28 is the lamination direction (stacking direction) of the light emitting elements of the light emitting section 25 .

As the one-dimensional diffusion optical element 28, various lenses and optical elements such as cylindrical lenses, lenticular lenses, micro-cylindrical lens arrays, elliptical diffusion films, binary optical elements, and diffractive optical elements can be used. A micro-cylindrical lens array is an array of micro-cylindrical lenses. Further, in the following description, as the one-dimensional diffusion optical element 28, any one of an ellipsoidal diffusion film, a binary optical element, and a diffractive optical element is used.

The distance measuring section 19 is controlled by the arithmetic control section 17 . When the pulsed distance measuring light 41 is emitted from the light emitting unit 25 onto the distance measuring optical axis 38 , the distance measuring light 41 is collimated by the collimator lens 26 and converted into a beam by the beam shaping optical element 27 . It is deflected at right angles while its shape is corrected. The distance measuring light 41 reflected by the beam shaping optical element 27 is diffused one-dimensionally by the one-dimensional diffusion optical element 28 and reflected by the reflecting prism 29 at right angles. The distance measuring optical axis 38 of the distance measuring light 41 emitted from the reflecting prism 29 through the fixing member 31 coincides with the axis 11a, and the distance measuring light 41 is transmitted by the scanning mirror 15. It is deflected at a right angle and illuminates the object to be measured through the window portion 32 . As the scanning mirror 15 rotates about the axis 11a, the distance measuring light 41 rotates (scans) within a plane that is orthogonal to the axis 11a and includes the axis 6a.

The window portion 32 is provided at a predetermined angle with respect to the optical axis of the distance measuring optical axis 38 so that the distance measuring light 41 reflected by the window portion 32 does not enter the light receiving element 34. ing.

The distance measuring light 41 (hereinafter referred to as reflected distance measuring light 42 ) reflected by the object to be measured is reflected at right angles by the scanning mirror 15 , passes through the light receiving optical system 37 and is received by the light receiving element 34 . The light receiving element 34 is, for example, an avalanche photodiode (APD) or an equivalent photoelectric conversion element.

The arithmetic control unit 17 measures each pulse of the distance measuring light 41 based on the time difference between the light emission timing of the light emitting unit 25 and the light reception timing of the light receiving element 34 (that is, the round trip time of the pulsed light) and the speed of light. Execute distance (Time Of Flight). The light emission timing of the light emitting unit 25, that is, the pulse interval can be changed via the operation panel 16. FIG.

The distance measuring unit 19 is provided with an internal reference light optical system (described later), and based on the time difference between the light receiving timings of the internal reference light (described later) received from the internal reference light optical system and the reflected distance measuring light and the speed of light, By performing distance measurement, more accurate distance measurement becomes possible.

The mounting portion 5 and the scanning mirror 15 rotate at a constant speed, respectively. 41 is scanned in two dimensions. By detecting the vertical angle and horizontal angle with the vertical angle encoder 14 and the horizontal angle encoder 9 for each pulsed light, vertical angle data and horizontal angle data can be obtained. From the vertical angle data, horizontal angle data, and distance measurement data, the three-dimensional coordinates of the object to be measured and the three-dimensional point cloud data corresponding to the object to be measured can be acquired.

Next, the light receiving optical system 37 will be described. 2A and 2B, only the principal ray of the distance measuring light 41 (the distance measuring optical axis 38) and the principal ray of the reflected distance measuring light 42 (the light receiving optical axis 39) are shown. is described.

The light-receiving prism 35 is a quadrilateral prism having a predetermined refractive index. A second surface 35b on which the reflected ranging light 42 is reflected, a third surface 35c on which the reflected ranging light 42 reflected by the second surface 35b and the first surface 35a is incident, and reflected by the third surface 35c. and a fourth surface 35d as a transmission surface through which the reflected distance measuring light 42 is transmitted. The reflected distance measuring light 42 transmitted through the fourth surface 35 d enters the light receiving element 34 .

A retroreflective reference prism 43 is provided below the scanning mirror 15 . Part of the distance measuring light 41 is incident on the reference prism 43 in the process of rotating the distance measuring light 41 through the scanning mirror 15 . The distance measuring light 41 retroreflected by the reference prism 43 enters the light receiving optical system 37 via the scanning mirror 15 and is received by the light receiving element 34 .

Here, the optical path length from the light emitting section 25 to the reference prism 43 and the optical path length from the reference prism 43 to the light receiving element 34 are known. Therefore, the distance measuring light 41 reflected by the reference prism 43 can be used as the internal reference light 44 . An internal reference beam optical system 45 is composed of the scanning mirror 15 and the reference prism 43 .

Next, with reference to FIGS. 3 to 6, the case where the surveying device 1 having the distance measuring section 19 performs measurement will be described. Various operations of the distance measuring unit 19 are performed by the arithmetic control unit 17 executing various programs. In addition, below, the case where a prism measurement is performed is demonstrated.

The distance measuring light 41 emitted from each light emitting element of the light emitting section 25 is applied to the collimator lens 26, the beam shaping optical element 27, the one-dimensional diffusion optical element 28, the reflecting prism 29, the fixed member 31, and the scanning light. An object to be measured, for example, a corner cube 46 is irradiated via the mirror 15 . The reflected distance measuring light 42 reflected by the corner cube 46 and incident on the light receiving optical system 37 via the scanning mirror 15 is refracted while passing through the light receiving lens 36 and the first surface 35a. The reflected distance measuring light 42 is sequentially reflected by the second surface 35b, the first surface 35a, and the third surface 35c inside the light receiving prism 35, passes through the fourth surface 35d, and is received by the light receiving prism 35. Light is received by element 34 .

The arithmetic control unit 17 calculates the three-dimensional coordinates of the corner cube 46 based on the distance measurement result of the distance measurement unit 19 and the detection results of the horizontal angle encoder 9 and the vertical angle encoder 14 .

The corner cube 46 is measured by scanning the entire circumference or the periphery of the corner cube 46 with the distance measuring light 41, and measuring the position where the reflected distance measuring light 42 is received as the position of the corner cube 46. may

Here, FIG. 3A shows the beam profile of the distance measuring light 41 when the one-dimensional diffusion optical element 28 is not used, and FIG. 4 shows the beam profile of the distance measuring light 41 in the case of FIG. 3C shows a comparison of beam profile cross-sectional intensities of each distance measuring light 41 at the position of line A. The case where the one-dimensional diffusion optical element 28 is not used is shown.

As shown in FIGS. 3A to 3C, when the one-dimensional diffusion optical element 28 is not used, the distance measuring light 41 of each light emitting element is independent while maintaining its shape. is ejected. Further, since the beam profile cross-sectional intensity at this time is also detected independently for each distance measuring light 41 of each light emitting element, the beam intensity of the beam cross section of the distance measuring light 41 varies greatly.

On the other hand, when the one-dimensional diffusion optical element 28 is used, the distance measuring light 41 of each light-emitting element is expanded in one-dimensional direction, for example, the stacking direction of the light-emitting elements. The distance measuring light 41 is superimposed, averaged, and emitted. In addition, since the profile cross-sectional intensity at this time is also detected in a state in which the distance measuring light 41 of each light emitting element overlaps and is averaged, the beam intensity of the beam cross section of the distance measuring light 41 becomes substantially constant.

4A and 4B show the beam profile of the distance measuring light 41 and the position of the corner cube 46 when the one-dimensional diffusion optical element 28 is used and when it is not used. shows the relationship between 4(A) and 4(B), 47 indicates the light receiving range of the light receiving element 34. As shown in FIG.

As shown in FIG. 4A, the distance measuring light 41 consists of distance measuring lights 41a to 41c pulsed from three light emitting elements. On the other hand, an error occurs in the results of distance measurement based on the distance measurement lights 41a to 41c due to an error in light emission timing of each light emitting element due to a manufacturing error or the like.

Therefore, when the corner cube 46 reflects the distance measuring light 41a (corner cube 46a) and when the corner cube 46 reflects the distance measuring light 41c (corner cube 46c), the corner cube 46 is When the distance measuring light 41b is reflected (corner cube 46b), an error of about ±5 mm is produced.

On the other hand, as shown in FIG. 4B, the distance measuring lights 41a to 41c diffused only in the lamination direction (one direction) of the light emitting elements by the one-dimensional diffusion optical element 28 overlap each other and are synthesized. , is homogenized. Further, an overlapping portion 41d where all of the distance measuring lights 41a to 41c are overlapped is received within the light receiving range 47. As shown in FIG.

As long as the distance measuring light 41 of the overlapping portion 41d is reflected, regardless of the position of the corner cube 46 (corner cubes 46d to 46i) where the light is reflected, as shown in FIG. Since the beam profile of the distance measuring light 41 is substantially uniform, no error occurs in the distance measurement result.

On the other hand, when the corner cube 46 is measured while the distance measuring light 41 is scanned by the cooperation of the mounting portion 5 and the scanning mirror 15, the distance measuring light 41a is measured like the corner cubes 46k and 46j. . . 41c or any two of the distance measuring lights 41a to 41c are overlapped.

In this case, compared with the case where the corner cube 46 reflects the distance measuring light 41 of the overlapping portion 46d, an error occurs in the distance measurement result. On the other hand, when the light-receiving element 34 receives the reflected distance measuring light 42, the amount of received light varies. Therefore, the arithmetic control unit 17 can determine whether the corner cube 46 reflects the distance measuring light 41 of the overlapping portion 41 d based on the difference in the amount of received light of the reflected distance measuring light 42 . Further, the calculation control section 17 can discard the distance measurement result determined to have been measured by the distance measurement light 41 other than the overlapping portion 41d as an erroneous distance measurement result.

Alternatively, it may be determined whether or not the corner cube 46 has been measured by the distance measuring light 41 of the overlapping portion 41d based on the light amount distribution when the corner cube 46 is scanned with the distance measuring light 41. . In this case, the horizontal angle and vertical angle of the center of gravity of the corner cube 46 are calculated based on the horizontal and vertical angles of each point from which the light intensity distribution is obtained, and within a predetermined angle range centered on the center of gravity (previously It can be determined whether or not the corner cube 46 has been measured by the distance measuring light 41 of the overlapped portion 41d, depending on whether the corner cube 46 is located within the set threshold range).

The calculation control unit 17 calculates the position of the center of gravity of the corner cube 46 based on the horizontal angle and vertical angle of each point from which the light intensity distribution is obtained, and based on a preset angle threshold value, each distance measurement result is the above-mentioned It is possible to determine whether or not the center of gravity of the corner cube 46 is within a threshold range, and to discard the distance measurement results determined to be outside the threshold range as erroneous distance measurement results.

5(A) and 5(B) show the horizontal position of the support portion 5 when the corner cube 46 is measured while scanning the distance measuring light 41 without using the one-dimensional diffusion optical element 28. 4 is a graph showing the relationship between the vertical angle of the scanning mirror 15 and the received light amount of the reflected distance measuring light 42. FIG. 6A and 6B show the mounting portion 5 when the one-dimensional diffusion optical element 28 is provided and the corner cube 46 is measured while scanning the distance measuring light 41. 4 is a graph showing the relationship between the horizontal angle, the vertical angle of the scanning mirror 15, and the received light quantity of the reflected distance measuring light 42;

5(B) and 6(B), the triangular plot 48 indicates the amount of light received in the V-axis direction (vertical direction), and the cross plot 49 indicates the amount of received light in the H-axis direction (horizontal direction). It shows the amount of received light.

As shown in FIG. 5B, when the one-dimensional diffusing optical element 28 is not provided and the received light signal is discretely sampled, the received light amount in the H-axis direction becomes a continuous distribution, but the received light amount in the V-axis direction becomes a continuous distribution. The amount of light, that is, the amount of received light in the stacking direction of the light emitting elements has a discontinuous distribution. Therefore, the error in calculating the position of the center of gravity of the corner cube 46 becomes large, and the angle measurement result of the corner cube 46 also has an error.

On the other hand, as shown in FIG. 6B, when the one-dimensional diffusing optical element 28 is provided, if the received light signal is discretely sampled, the amount of received light in both the V-axis direction and the H-axis direction becomes a continuous distribution. Therefore, it is possible to prevent an error in calculating the center of gravity position of the corner cube 46, and an error in the angle measurement result of the corner cube 46 can also be prevented.

As described above, in this embodiment, as the light emitting section 25, a multi-stack laser light source is used in which a plurality of light emitting elements are stacked in one direction and each light emitting element emits light at the same time. Therefore, by summing the received light signals emitted from each light emitting element and received by the light receiving element 34, the amount of received light can be substantially increased by approximately the number of light emitting elements. can be done. As a result, the reachable distance of the range-finding light 41 can be extended, and the range-measurable distance can be extended.

Further, since the one-dimensional diffusion optical element 28 for diffusing the distance measuring light 41 only in the lamination direction (one direction) of the light emitting elements is used in the light projecting optical system 33, the light emitted from each light emitting element All the distance measuring lights 41a to 41c are superimposed to form the overlapping portion 46d with a uniform beam profile.

Therefore, if the distance measuring light 41 of the overlapping portion 46d is used, even if the corner cube 46 is measured at any portion, a uniform distance measuring result can be obtained regardless of the number of laminated light emitting elements. Distance accuracy can be improved.

Further, even when the corner cube 46 is measured by scanning the distance measuring light 41, a distribution of the amount of light received continuously in both the V-axis direction and the H-axis direction can be obtained. An accurate center-of-gravity position can be calculated, and angle measurement accuracy of the corner cube 46 can be improved. Since the one-dimensional diffusion optical element 28 can improve the accuracy of distance measurement and the accuracy of angle measurement, the measurement accuracy of the surveying instrument 1 can be improved.

Further, when the corner cube 46 is measured by the distance measuring light 41 other than the overlapping portion 46d, the reflection measurement is more effective than when the corner cube 46 is measured by the distance measuring light 41 of the overlapping portion 46d. A difference occurs in the received light amount of the distance light 42 .

Therefore, by discarding the measurement results of the corner cube 46 measured by the distance measuring light 41 other than the overlapping portion 46d based on the difference in the amount of received light of the reflected distance measuring light 42, the measurement results having errors can be eliminated. It can be removed, and the measurement accuracy can be improved.

Also, the one-dimensional diffusion optical element 28 is a one-dimensional diffusion optical element that diffuses the distance measuring light 41 only in one direction, and is more effective than a two-dimensional diffusion optical element that diffuses the distance measurement light 41 in two directions. The beam diameter of the distance light 41 can be reduced.

Therefore, the received light amount of the reflected distance measuring light 42 can be increased, and the range-measurable distance can be extended.

The light receiving prism 35 is used as the light receiving optical system 37, and the reflected distance measuring light 42 is internally reflected within the light receiving prism 35 a plurality of times. Thereby, the optical path of the reflected distance measuring light 42 is bent, and the optical path length corresponding to the focal length of the light receiving lens 36 is secured.

Therefore, since the length of the light receiving optical system 37 in the optical axis direction can be shortened, the size of the optical system of the distance measuring unit 19 can be reduced, and the overall size of the surveying instrument can be reduced.

In this embodiment, the light emitting section 25 is a multi-stack laser light source in which three light emitting elements are stacked. On the other hand, the light emitting section 25 may be a multi-stack laser light source in which two light emitting elements are stacked, or may be a multi-stack laser light source in which four or five light emitting elements are stacked.

In this embodiment, the one-dimensional diffusing optical element 28 is provided on the distance measuring optical axis 38, but the one-dimensional diffusing optical element 28 is moved to the distance measuring optical axis 38 by a driving mechanism such as a solenoid. It may be made removable with respect to. By making the one-dimensional diffusion optical element 28 insertable and removable, the one-dimensional diffusion optical element 28 can be inserted onto the distance measuring optical axis 38 when performing prism measurement, and the one-dimensional diffusion optical element 28 can be inserted when performing non-prism measurement. The dimensional diffusion optical element 28 can be removed from the distance measuring optical axis 38, and the distance measuring light 41 can be selectively used according to the object to be measured, thereby improving workability.

In this embodiment, the surveying instrument 1 is a laser scanner, but it goes without saying that the construction of this embodiment can also be applied to a total station.

In this embodiment, the one-dimensional diffusing optical element 28 is arranged between the beam shaping optical element 27 and the reflecting prism 29, but the one-dimensional diffusing optical element 28 may be arranged at another position. . For example, the one-dimensional diffusing optical element 28 may be placed between the collimator lens 26 and the beam shaping optical element 27, as shown in FIG.

Further, if the use of the surveying instrument 1 is limited to prism measurement only, that is, if the one-dimensional diffusion optical element 28 is fixed with respect to the distance measuring optical axis 38, the one-dimensional diffusion optical element 28 is It may be arranged between the fixed member 31 and the scanning mirror 15 , or may be arranged between the scanning mirror 15 and the window portion 32 . Further, instead of the one-dimensional diffusion optical element 28, a thin film having an optical action of diffusing light in one-dimensional direction is formed on the reflecting prism 29, the fixed member 31, the scanning mirror 15, and the window portion 32. can be formed to

In this embodiment, the one-dimensional diffusion optical element 28 is an elliptical diffusion film, a binary optical element, or a diffraction optical element. A lens array may also be used.

When a cylindrical lens, a lenticular lens, and a micro-cylindrical lens array are used and these are further optimized by making them aspherical, the beam profile of the range-finding light 41 can be obtained like the profile cross-sectional intensity of each range-finding light shown in FIG. can be made uniform over the entire area, the measurement accuracy can be further improved.

1 Surveying Device 3 Surveying Device Main Body 5 Mounting Section 8 Horizontal Rotation Motor 9 Horizontal Angle Encoder 13 Vertical Rotation Motor 14 Vertical Angle Encoder 15 Scanning Mirror 17 Calculation Control Unit 19 Distance Measuring Unit 23 Distance Measuring Light Emitting Unit 24 Distance Measuring Light Receiving Unit 25 light emitting unit 28 one-dimensional diffusion optical element 41 ranging light 42 reflected ranging light 46 corner cube

Claims (7)

A distance measuring light emitting part having a light emitting part for emitting distance measuring light to a measurement object, a one-dimensional diffusion optical element for diffusing the distance measuring light in a one-dimensional direction, and a distance measuring light reflected from the measurement object. and an arithmetic control unit that controls the light emitting unit and calculates the distance to the object to be measured based on the result of receiving the reflected distance measuring light with respect to the light receiving element. A surveying instrument according to claim 1, wherein the light emitting section has at least two light emitting elements stacked in one direction, and the one-dimensional diffusion optical element is configured to diffuse the distance measuring light in the stacking direction of the light emitting elements. The measurement object is a corner cube having retroreflectivity, and the distance measuring light diffused by the one-dimensional diffusion optical element has an overlapping portion where all the lights emitted from the light emitting elements overlap, 2. A surveying instrument according to claim 1, configured to range said corner cube at said overlapping portion. A mount horizontally rotated about a horizontal rotation axis by a horizontal rotation motor, and vertically rotated about a vertical rotation axis by a vertical rotation motor provided in the mount, and irradiates the corner cube with the distance measuring light. and a scanning mirror for receiving the reflected ranging light from the corner cube, a horizontal angle encoder for detecting the horizontal angle of the mounting portion, and a vertical angle encoder for detecting the vertical angle of the scanning mirror. The calculation control unit calculates the position of the center of gravity of the corner cube based on the amount of received light of the reflected distance measuring light, the horizontal angle and the vertical angle when the corner cube is scanned with the distance measuring light, and calculates the position of the center of gravity of the corner cube. 3. The surveying instrument of claim 2, wherein the surveying instrument is configured to measure the angle of the corner cube based on position. The arithmetic control unit determines whether or not the corner cube has been measured in the overlapping portion based on the amount of received light of the reflected distance measuring light, and outputs the distance measurement result determined that the distance was not measured in the overlapping portion. 4. A surveying instrument according to claim 2 or 3, adapted to be discarded. The arithmetic control unit calculates the position of the center of gravity of the corner cube based on the light amount distribution obtained when the corner cube is scanned with the distance measuring light, and the position of the center of gravity is within a preset threshold range from the position of the center of gravity. 4. The surveying according to claim 3, wherein it is determined whether or not the corner cube has been measured in the overlapping portion by whether Device. According to any one of claims 1 to 5, the distance measuring light emitting unit further comprises a driving mechanism, and the driving mechanism is configured to insert and remove the one-dimensional diffusion optical element with respect to the optical axis of the distance measuring light. The surveying instrument according to any one of the items. 7. The range-finding light receiver according to claim 1, further comprising a light-receiving prism that causes the light-receiving element to receive the reflected range-finding light after internally reflecting the reflected range-finding light multiple times. surveying equipment.

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