JP2022132526A - Target device and measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique to measure the posture of a measurement object using a laser beam.

SOLUTION: A target device 130 includes a spiral target 120 with a spiral rugged structure on a surface, and a reflection prism 110 disposed on a spiral axis of the spiral target 120. On the premise that a distance between a position of a particular part of the spiral rugged structure viewed from a particular direction and a position of a reflection center of the reflection prism 110 is L, and a rotation angle of the spiral target with respect to a reference rotation position around the spiral axis is θ, a relation between L and θ is obtained in advance.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to surveying technology for detecting the orientation of a target.

In surveying using a TS (total station), a target device having a rod-shaped member with a reflecting prism is used (see, for example, Patent Document 1). In surveying using this target device, the tip of a vertical rod-shaped member is placed in contact with the ground, and the reflecting prism is used as a target for positioning by TS. Get coordinates. By performing this work at various locations on the land to be surveyed, the land is surveyed.

In the above work, the worker holds the target device in his/her hand and surveys at a plurality of positions while moving on foot. At this time, the worker is guided to the next survey position from the TS side using a terminal or the like held by the worker. At this time, it is convenient to know the horizontal angle (direction in the horizontal plane) of the target device with respect to the TS. The horizontal angle is usually detected using a magnetic sensor or a gyro sensor. A technique for detecting an orientation using GPS is also known.

JP 2009-229192 A

Detection of horizontal angles by magnetic sensors is affected by metal structures. For example, near bridges, they are affected by reinforcing bars and steel frames in concrete. There is also a technique of driving corrugated steel material into the ground to reinforce the ground, but the steel material in the ground may affect the accuracy of the magnetic sensor. Also, the gyro sensor has a problem of output drift. Although there is a gyro sensor that improves on this point, it is expensive and large. GPS cannot be used (or even if it can be used, its accuracy is reduced) in places where navigation satellites cannot be seen (valleys, under bridges, in tunnels, indoors, underground, forests, etc.).

The above problem also occurs when it is desired to know the orientation of a UAV (Unmanned aerial vehicle) with respect to the TS. For example, techniques for tracking UAVs by TS are known (US2014/0210663). In this technology, it is important to know the attitude of the UAV with respect to the TS, but detection of the attitude using the above-mentioned azimuth sensor, gyro sensor, and GPS causes problems similar to those described above.

In view of such a background, an object of the present invention is to provide a technology capable of measuring the orientation of a survey object using laser light.

The present invention comprises a helical target having a helical uneven structure on its surface, and a reflecting prism arranged on the helical axis of the helical target, and the helical uneven structure is viewed from a specific direction. The relationship between L and θ is obtained in advance, where L is the distance between the position of the portion and the position of the center of reflection of the reflecting prism, and θ is the rotation angle of the spiral target with respect to the reference rotation position around the spiral axis. It is a target device that is

The present invention is a surveying method for surveying a target device having a helical target having a helical uneven structure on its surface and a reflecting prism arranged on the helical axis of the helical target with a surveying instrument, The surveying device includes a functional unit that performs positioning using distance measuring light and a laser scanner unit that performs laser scanning, and measures the position of a specific portion of the spiral concave-convex structure and the reflection of the reflecting prism when viewed from a specific direction. The relationship between L and θ is obtained in advance, where L is the distance between the target and the center position, and θ is the rotation angle of the helical target with respect to the reference rotational position around the helical axis. The position of the reflecting prism is measured by positioning using distance measuring light, the position of the specific portion is measured by laser scanning using the laser scanner unit of the surveying instrument, and the measured reflecting prism is measured. and the measured position of the specific portion, and based on the calculated distance and the previously acquired relationship between the L and the θ of the target device It is a surveying method for obtaining a rotation angle about the spiral axis with respect to the reference rotation position.

According to the present invention, it is possible to obtain a technique capable of measuring the attitude of an object to be surveyed using a laser beam.

1 is a conceptual diagram of an embodiment; FIG. 1 is a perspective view of a surveying instrument according to an embodiment; FIG. 1 is a front view of a surveying instrument according to an embodiment; FIG. FIG. 2 is a principle diagram showing a mechanism for measuring the horizontal angle of a helical target; 4 is a graph showing the relationship between the horizontal angle (horizontal axis) and the distance L (vertical axis) between the position of the trough of the spiral target and the position of the center of reflection of the omni-reflecting prism. FIG. 4 is a diagram illustrating a method of obtaining a horizontal angle of a target device in an absolute coordinate system; FIG. 10 illustrates a method for determining the location of the troughs of a spiral target; 1 is a block diagram of a surveying instrument; FIG. 4 is a flow chart showing an example of a procedure of processing; It is a figure which shows an example of the display screen of a terminal. It is a figure which shows an example of the display screen of a terminal. FIG. 10 is a conceptual diagram showing an outline of another embodiment; FIG. 10 is a conceptual diagram showing an outline of another embodiment; It is a figure which shows the waveform pattern of the cross-sectional shape of a helical target. FIG. 5 is a diagram showing the relationship between the optical axis of the distance measuring light of the TS function unit and the laser scanning direction; FIG. 2 is a principle diagram showing a mechanism for measuring the horizontal angle of a helical target; FIG. 2 is a principle diagram showing a mechanism for measuring the horizontal angle of a helical target;

1. First embodiment (outline)
FIG. 1 shows an overview of the embodiment. FIG. 1 shows an all-around reflecting prism 110, which is a first target to be laser-positioned, and a helical target, which is a second target having a surface of a helical structure, in which the positional relationship between the all-around reflecting prism 110 is specified. 120, a target device 130 in which detection of the rotational position about the axis of the helical structure is performed based on the position of the omni-reflecting prism 110 and the positional relationship of the concave-convex structure in the helical structure.

In FIG. 1, the surveying instrument 400 measures the position and horizontal angle (orientation in the horizontal direction) of the target device 130 . Here, the surveying instrument 400 is horizontally installed at a position whose coordinates are known in the absolute coordinate system, and the azimuth in the horizontal direction in the absolute coordinate system is determined. This is the same as in a surveying instrument such as a normal TS.

The absolute coordinate system is the coordinate system used in GNSS. In the absolute coordinate system, coordinates are specified by longitude, latitude, and altitude above mean sea level. A local coordinate system determined on the spot can also be used as the coordinate system.

(surveying instrument)
The surveying instrument 400 will be described below. A surveying instrument 400 has a configuration in which a TS function section 200 and a laser scanner section 300 are combined. The TS function unit 200 functions as a TS (total station). TS is described, for example, in Japanese Patent Application Laid-Open Nos. 2009-229192 and 2012-202821.

The laser scanner unit 300 performs processing (laser scanning) for obtaining a laser scanning point group. Techniques related to laser scanners are described, for example, in Japanese Unexamined Patent Application Publication No. 2010-151682, Japanese Unexamined Patent Application Publication No. 2008-268004, and US Pat. No. 8,767,190. Further, as the laser scanner, it is also possible to employ a form in which scanning is performed electronically, as described in US Publication No. US2015/0293224.

The surveying instrument 400 will be described below with reference to FIGS. 2 and 3. FIG. The surveying instrument 400 has a horizontal rotating section 11 . The horizontal rotation unit 11 is held on a base 12 so as to be horizontally rotatable. The pedestal 12 is fixed to the top of a tripod (not shown). The horizontal rotation part 11 has a substantially U-shape with two extensions extending upward. is maintained in a state in which it is possible to control

The horizontal rotation unit 11 electrically rotates horizontally with respect to the base 12 . The vertical rotating part 13 is rotated in a vertical plane by a motor. Angle control in the horizontal plane of the horizontal rotation section 11 is performed by a horizontal rotation driving section 207 (see FIG. 8) incorporated in the horizontal rotation section 11 . The angle control of the vertical rotation section 13 in the vertical plane is performed by a vertical rotation driving section 208 (see FIG. 8) incorporated in the horizontal rotation section 11 .

The horizontal rotation section 11 is provided with a horizontal rotation angle control dial 14a and an elevation angle control dial 14b. By operating the horizontal rotation angle control dial 14a, the horizontal rotation angle of the horizontal rotation section 11 is adjusted, and by operating the elevation angle control dial 14b, the elevation angle of the vertical rotation section 13 in the vertical plane ( elevation and depression) adjustments are made.

A sighting device 15a for roughly aiming is arranged on the upper part of the vertical rotation part 13 . Further, the vertical rotating portion 13 is provided with an optical sighting device 15b (see FIG. 3) having a narrower field of view than the sighting device 15a and a telescope 16 capable of more precise sighting.

An optical system for guiding an image captured by the sighting device 15 b and the telescope 16 to the eyepiece 17 is housed inside the vertical rotating portion 13 . The image captured by the sighting device 15 b and the telescope 16 can be visually recognized by looking through the eyepiece 17 . The image captured by the telescope 16 can be captured by a camera 211 (see FIG. 8) arranged inside the vertical rotating section 13 .

The telescope 16 also serves as an optical system for laser light for distance measurement and tracking light for tracking and capturing an object for distance measurement (for example, a dedicated reflecting prism serving as a target). The optical system is designed so that the optical axes of the ranging light and the tracking light are aligned with the optical axis of the telescope 16 . The structure of this portion is the same as the commercially available TS.

Displays 18 and 19 are attached to the horizontal rotating section 11 . The display 18 is integrated with the operation section 210 . The operation unit 210 has a numeric keypad, a cross operation button, etc., and various operations and data input related to the surveying instrument 400 are performed. The displays 18 and 19 display various information necessary for operating the surveying instrument 400, survey data, and the like. The reason why there are two displays on the front and rear is that the displays can be viewed from either the front or the rear without rotating the horizontal rotation section 11 .

A laser scanner unit 300 is fixed to the upper portion of the horizontal rotation unit 11 . The laser scanner section 300 has a first tower section 301 and a second tower section 302 . The first tower section 301 and the second tower section 302 are connected at a joint section 303, and the space above the joint section (the space between the first tower section 301 and the second tower section 302) is scanned. It is covered with a protective case 304 made of a member that transmits laser light. Inside the protective case 304 , a columnar rotating part 305 that horizontally protrudes from the first tower part 301 is arranged. The tip of the rotating part 305 has an obliquely cut off shape, and an oblique mirror 306 is fixed to the tip.

The rotating part 305 is driven by a motor housed in the first tower part 301, and rotates about its extending direction (horizontal direction) as a rotation axis. In addition to the motor, the first tower section 301 houses a drive circuit for driving the motor, a control circuit for the motor, a sensor for detecting the rotation angle of the rotating section 305, and peripheral circuits for the sensor.

Inside the second tower part 302, there are a light emitting part for emitting laser scanning light, a light receiving part for receiving laser scanning light reflected from an object, an optical system related to the light emitting part and the light receiving part, a scanning point It contains a distance calculator that calculates the distance to. The laser scanner unit 300 also includes a scan point position calculator that calculates the three-dimensional coordinates of the scan point based on the rotation angle of the rotation unit 305, the horizontal rotation angle of the horizontal rotation unit 11, and the distance to the scan point.

The laser scanning light is a single line, is irradiated from the inside of the second tower section 302 toward the oblique mirror 306 , is reflected there, and is irradiated to the outside through the transparent case 304 . The laser scanning light is pulse-lighted from the light-emitting portion at a repetition frequency of several kHz to several hundreds of kHz, is irradiated horizontally to the oblique mirror 306 at the tip of the rotating rotating portion 305, and is reflected at right angles there. As the rotating part 305 rotates around the horizontal axis, the laser scanning light is scanned along the vertical plane and pulse-irradiated radially in spots.

In the surveying instrument 400, when radial laser scanning from the laser scanner unit 300 is performed on a vertical plane, laser scanning is performed along the vertical line (see FIG. 15). That is, the radial laser scanning light from the laser scanner unit 300 forms a set of bright points (reflection points) distributed on the vertical line on the vertical surface. As shown in FIG. 15, the positional relationship between the TS function unit 200 and the laser scanner unit 300 is set so that the vertical line formed by the bright spots of the laser scanning light from the laser scanner unit 300 and the optical axis of the telescope 16 intersect. It is

That is, the surveying instrument 400 is set so that the optical axis of the telescopic pole 16 is included in the fan-shaped scanning plane (the plane swept by the scanning laser light) on which the laser scanning from the laser scanner unit 300 is performed. In this configuration, the scanning direction in the elevation angle direction of the laser scanner unit 300 is orthogonal to the horizontal direction, and the horizontal angle of the scanning light (direction in the horizontal direction) and the horizontal angle of the optical axis of the telescope 16 (the TS function unit 200 horizontal angle) match.

Further, by performing the above-described laser scanning while rotating the horizontal rotation unit 11 horizontally, the laser scanning is performed within a required range.

The scanning light reflected from the object traces a path opposite to that of the irradiation light and is received by the light receiving section inside the second tower section 302 . The scanning point (reflecting point of the scanning light) can be measured by the timing of light emission and light reception of the scanning light, as well as the angular position (elevation angle: angle of elevation or angle of depression) of the rotating section 305 and the horizontal rotation angle of the horizontal rotating section 11 at that time. done. The principle of positioning is the same as that of the distance measuring unit 202, which will be described later.

The target device 130 is used for positioning work at a civil engineering construction site or the like. During this operation, positioning is performed by the TS function unit 200 targeting the all-around reflection prism 110 . The target device 130 includes a rod-shaped member 131 serving as a support member, an all-around reflection prism 110 fixed to the top of the rod-shaped member 131, a spiral target 120 fixed to the top of the all-around reflection prism 110, and an upper portion of the spiral target 120. It has a terminal 132 that is fixed via a support to the base.

The total reflection prism 110 changes the direction of incident light by 180° and reflects it. As the total reflection prism 110, a normal product used for surveying using TS is adopted. Here, the reflection center P of the omni-reflection prism 110 is adjusted to be on the spiral axis of the spiral target 120 . A reflecting prism that is not of the all-round reflection type can also be used, but there is a limit to the range of angles that can be handled. Spiral target 120 will be described later.

The terminal 132 includes an image display device such as a liquid crystal display. This image display device provides a guide display that guides the operator handling the target device 130 to the position of the positioning work using the all-around reflection prism 110 . This guide display will be described later. A tablet or a smartphone is used as the terminal 132 . A dedicated terminal may be prepared as the terminal 132 .

For example, the case of piling work will be described. Piling work is the work of identifying a predetermined position on a drawing at a construction site or a civil engineering work site and driving a marker stake there (or attaching some kind of marker). is. In this work, the work of searching for a stakeout point→specifying it→stakeout at that position is performed for a plurality of stakeout candidate positions. At this time, the target device 130 is used to specify the staked points.

For example, the worker moves on foot to the planned pile driving position while holding the rod-shaped member 131 by hand. At this time, the operator uses the guide display on the terminal 132 to move to the target position. At this time, a guide display is created using information on the direction (orientation) in the horizontal direction of the target device 130 obtained using the spiral target 120 . A technique related to this guide display will be described later.

The stake-out point is specified by bringing the tip of the rod-shaped member 131 into contact with the ground surface, standing the target device 100 there, and performing positioning of the total reflection prism 110 by the TS function unit 200 . This work is the same as normal survey work using TS.

(spiral target)
FIG. 4 shows a side view (perpendicular to the helical axis) of the target device 130 composed of the omni-reflection prism 110 and the helical target 120 fixed thereon. The target device 130 has a level (not shown), and is installed so that the helical axis (Z-axis in FIG. 4) of the helical target 120 is vertical.

A helical shaft is a helical structure shaft, and an example of a helical shaft is a rotation shaft of a screw. The target device 130 is fixed on top of a rod-shaped member that serves as a support member, but the rod-shaped member is omitted in FIG. The terminal 132 and its supporting structure are also omitted from the drawing.

The helical target 120 has a helical axis extending in the extending direction of the rod-shaped member 131 . The helical structure is set so that the phase advances by one period (phase difference of 2π) for one rotation around the axis. In other words, when the spiral is rotated once around the spiral axis, the same shaped portion seen from the side moves in the direction of the spiral axis with a phase difference of 2π. Although the structure of the spiral is not limited to this, this structure is the simplest.

The shape of the uneven cross-section of the spiral surface is a triangular wave shape in which triangles are repeated. The surface of the spiral target 120 serves as a reflecting surface for laser scanning light. For the surface of the helical target 120, a material and state are selected that reflect the laser scanning light in an appropriate reflection state.

Now, consider the state of (A) as a reference state. Here, it is assumed that the helical axis of the helical target 120 is vertical. In the lower part of (A), the direction of the viewpoint viewed vertically from above is conceptually shown.

Here, consider a case where the target device 130 (spiral target 120) is rotated 1/4 to the right (90 degrees clockwise) when viewed vertically from above from the state of (A). In this case, it can be seen that the helical structure advances upward (in the positive direction of the Z-axis) with a phase difference of π/2. That is, the appearance state shifts from (A) to (B).

In this case, the position (BTM) of the trough of the spiral target 120 on the vertical line including the optical axis of the TS function unit 200 moves from state (A) to state (B). Considering the period of the spiral, the movement amount at this time is equivalent to 1/4 period. The phenomenon that the trough position (BTM) advances due to the rotation of the spiral is based on the same principle as the trough portion of the screw thread advances as the screw rotates.

Here, if the direction of rotation is reversed, the trough position (BTM) moves in the opposite direction (negative direction of the Z-axis). In this way, the trough position (BTM) on the vertical line that intersects the optical axis of the TS function unit 200 moves along the spiral axis (Z-axis) as the spiral target 120 rotates.

That is, the distance L between the trough position (BTM) of the helical structure on the helical axis and the center of reflection of the all-around reflecting target 110 changes as the helical target 120 rotates. FIG. 4 shows a state in which L=L1 in the state of (A) becomes L=L2 (L1<L2) by rotating the helical target 120 by 1/4.

Here, it is assumed that the state of FIG. 4A is the front view of the helical target 120 viewed from the surveying instrument 400, and the horizontal rotation angle Dm of the helical target 120 with respect to the surveying instrument 400 is 0°. Then, from the state of FIG. 4A, assuming that the clockwise direction is +rotation and the reverse rotation direction is −rotation when viewed from the vertically upward direction, the distance between the above distance L and the horizontal rotation angle Dm is as shown in FIG. There is a relationship

By the way, the position of the trough on the spiral axis of the spiral target 120, that is, the height V1 in the vertical direction can be specified by laser scanning according to the principle described later. On the other hand, the position (height V2) of the reflection center P of the omnidirectional reflection target 110 on the spiral axis can be specified by the TS function unit 200 . Therefore, the value of L in FIG. 4 can be calculated from V1-V2.

Therefore, the relationship shown in FIG. 5 is acquired in advance. Then, the value of L is calculated from the difference between the vertical position of the valley (BTM) obtained from the laser scanning of the spiral target 120 and the vertical position of the reflection center P of the omnidirectional reflection target 110 obtained by the TS function unit 200. By applying this value of L to the relationship in FIG. 5, the horizontal angle Dm (see FIG. 6), which is the horizontal orientation of the spiral target 120 (target device 130) with respect to the surveying instrument 400, can be obtained.

The horizontal angle Hm of the TS function unit 200 with respect to the reference direction (for example, the north direction) is obtained when the surveying instrument 400 is installed and is known. Therefore, the horizontal angle Ht in the absolute coordinate system of the target device 130 can be obtained from the relationship shown in FIG.

A method for calculating Ht will be described below. First, it is assumed that the horizontal angle Hm of the TS function unit 200 is measured as an angle in the clockwise direction with north as a reference. Since the surveying instrument 400 is calibrated to determine the horizontal angle reference when it is installed, the horizontal angle Hm is obtained from the output of the horizontal angle detection unit 205 .

Dm is the angle formed by the reference direction of the horizontal angle of the target device 130 (the front direction in this case) and the optical axis of the TS function unit 200 . Dm is obtained from the relationship in FIG. 5 by determining the vertical distance L between the valley position BTM in FIG.

Here, Ht is an angle measured clockwise with north as a reference, and is calculated from the horizontal angles Hm and Dm by the formula shown in FIG. Thus, the horizontal angle Ht (orientation in the horizontal direction) in the absolute coordinate system of the target device 130 is calculated.

FIG. 4 can be regarded as a method of obtaining the horizontal angle of the helical target 120 (target device 130) based on the phase difference of the helical with respect to the reflection center P of the omni-reflecting prism 110. FIG. That is, in FIGS. 4A and 4B, the state of the phase of the helical concave-convex structure (triangular wave structure) with respect to the position on the vertical line of the reflection center P of the total reflection prism 110 is different. Specifically, in the state of (B), the phase of the spiral (the phase of the triangular wave) with respect to the center of reflection P is advanced by 1/4 period (π/2) with respect to the state of (A). There is a unique relationship between this phase state difference and the rotational position (horizontal angle) of the helical target 120 . This univocal relationship is shown in FIG.

That is, in the example of FIG. 4, the difference in the phase state of the helical structure is detected as the difference in the trough position BTM, and L is used as a specific parameter. This phase difference can be grasped by parameters that characterize the corrugations of the helical structure in addition to the troughs. According to this technique, by obtaining in advance the relationship between the shape of the unevenness of the helical structure and the angle of horizontal rotation, the horizontal angle of the helical target can be calculated from the uneven shape of the helical structure viewed from the direction perpendicular to the helical axis. A rotational position can be determined.

(How to find the position of the valley)
A method for obtaining the position of the valley of the spiral target 120 in FIG. 4 (the position of the valley on the vertical line intersecting the optical axis of the TS function unit 200) will be described. The processing related to the calculation of the position of the valley is performed by the position calculation section 217 of a specific portion within the surveying instrument 400 .

FIG. 7 describes the principle of the process of locating the troughs of the spiral. In this technique, the laser scanner unit 300 performs linear laser scanning along a vertical line that intersects the optical axis of the TS function unit 200 . 7(A) shows the helical target 120, FIG. 7(B) shows the distribution of laser scan points on the helical structure surface at the first rotation angle, and FIG. 7(C) , the distribution of laser scan points on the helical surface at a second rotation angle.

In this example, planes are employed as slopes of spiral crests. Therefore, the equation of the line along the slope is obtained from multiple scan points along the surface of the spiral, the three-dimensional position of the valley is obtained from the intersection of two vertically adjacent lines, and the coordinates in the vertical direction are obtained. . The location of the valley (BTM) is thus determined. As a method of finding the position of the valley (BTM), it is also possible to find the positions of the tops of two mountains sandwiching the valley and find the intermediate value between them.

Then, the distance L between the position of the valley (BTM) in the vertical direction and the reflection center P of the total reflection prism 110 is calculated. ) is obtained (Dm in FIG. 6).

As described above, the rotational position of the helical target around the helical axis is specified using the periodicity in the axial direction of the helical structure of the helical target.

(TS/laser scanner combined type surveying instrument)
The internal configuration of the surveying instrument 400 in FIG. 1 will be described. FIG. 8 shows a block diagram (configuration diagram) of the surveying device 400. As shown in FIG.

The TS function unit 200 includes a storage unit 201, a distance measurement unit 202, a tracking light transmission unit 203, a tracking light reception unit 204, a horizontal angle detection unit 205, an elevation angle detection unit 206, a horizontal rotation drive unit 207, and a vertical rotation drive unit. 208, displays 18 and 19, an operation unit 210, a camera 211, an arithmetic control unit 212, a communication unit 216, and a position calculation unit 217 of a specific portion. Further, the calculation control section 212 includes a positioning calculation section 213 , a scan density setting section 214 and a horizontal angle calculation section 215 . At least one of the positioning calculation unit 213 , the scan density setting unit 214 , and the horizontal angle calculation unit 215 can be configured separately from the calculation control unit 212 .

The storage unit 201 is configured by a data storage device such as a semiconductor memory circuit. The storage unit 209 stores data necessary for the operation of the surveying instrument 400, an operation program, and data obtained by the operation.

The distance measuring unit 202 measures the distance between the surveying instrument 400 and the distance measuring object (the all-around reflecting prism 110). A predetermined position such as the position of the light emitting unit of the distance measuring unit 202 or the imaging position within the telescope 16 is used as the origin of distance measurement.

The distance measuring unit 202 includes a light-emitting element (laser diode or the like) that emits distance-measuring light, a peripheral circuit of the light-emitting element, and a light-receiving element (photo diode, etc.), a peripheral circuit of the light receiving element, and an arithmetic circuit for calculating the distance to the object based on the output of the light receiving element.

Positioning processing in the distance measurement unit 202 is performed as follows. The distance measuring light from the light emitting element is divided into two by an optical system such as a half mirror, one of which is irradiated to the positioning target, and the other of which is guided to a reference optical path (not shown). The optical path length of the reference optical path is known, and the distance measuring light transmitted through the reference optical path is guided to the light receiving element as the reference distance measuring light. The light receiving element receives the distance measuring light reflected from the positioning object and the reference distance measuring light transmitted through the reference optical path.

Since the distance measuring light reflected by the positioning target and the reference distance measuring light from the reference optical path arrive at the light receiving element at different timings, there is a phase difference between the output signals (detection signals) of both light receiving elements. . The distance to the positioning object is calculated from this phase difference. Calculation of this distance is performed by an arithmetic circuit in the distance measurement unit 202 .

The tracking light transmitting unit 203 emits tracking light for tracking the target (the all-around reflecting prism 110), which is a positioning object. The tracking light receiving section 204 receives tracking light reflected from the target. The tracking light receiving unit 204 is composed of a CCD or CMOS image sensor. The horizontal angle and the elevation angle of the optical axis of the distance measuring unit 202 are controlled so that the reflected light from the target of the tracking light becomes the center of the field of view. The horizontal angle and elevation angle of the optical axis are controlled by the horizontal rotation drive section 207 and the vertical rotation drive section 208 based on control signals generated by the arithmetic control section 212 .

The horizontal angle detection unit 205 detects the horizontal angle of the horizontal rotation unit 11 (see FIG. 1). A horizontal angle is detected by a rotary encoder. The horizontal angle detection unit 205 also detects the horizontal rotation angle of the laser scanner unit 300 . The elevation angle detection unit 206 detects the elevation angle (angle of elevation and angle of depression) of the vertical rotation unit 13 . A vertical angle is detected by a rotary encoder.

The horizontal rotation driving section 207 drives the horizontal rotation of the horizontal rotation section 11 . Drive is provided by a motor. The horizontal rotation section 207 also horizontally rotates the laser scanner section 300 . The vertical rotation drive unit 208 drives the vertical rotation (elevation angle and depression angle operation) of the vertical rotation unit 13 . Drive is provided by a motor.

The displays 18 and 19 display various image information necessary for operating the surveying instrument 400 and image information of survey results. A liquid crystal display or an organic EL display is adopted as the displays 18 and 19 . The operation unit 210 is an operation interface having various buttons and the like for operating the surveying instrument 400 . A camera 211 captures the image captured by the telescope 16 .

The arithmetic control unit 212 has a function as a computer including a CPU, a memory, and various interfaces, and controls the overall operation of the surveying instrument 400 . A mode is also possible in which a part of the calculation in the calculation control unit 212 is performed by a dedicated IC such as an FPGA. This is the same for the position calculator 217 of a specific portion. The calculation control section 212 includes a positioning calculation section 213 , a scan density setting section 214 and a horizontal angle calculation section 215 .

The positioning calculation unit 213 performs calculations related to positioning of the object (for example, the total reflection prism 110) measured by the distance measurement unit 202 (measurement of the position of the object with respect to the surveying instrument 400). Calculations related to the positioning of the object in the positioning calculation unit 213 are performed as follows. In this process, the distance measuring unit 202 measures distance data based on the distance measurement data of the object obtained by the distance measuring unit 202 and the direction of the optical axis of the distance measuring light obtained by the horizontal angle detecting unit 205 and the elevation angle detecting unit 206. The position of the distanced object (omnidirectional reflection target 110) is calculated. That is, the position (three-dimensional coordinates) of the object with respect to the surveying instrument 400 is calculated from the distance and direction.

The scan density setting unit 214 sets the scan density of the laser scanning of the spiral target 120 by the laser scanner unit 300 according to the distance from the surveying instrument 400 measured by the distance measuring unit 202 to the total reflection prism 110 . With this setting, the scan speed is adjusted so that the scan density does not become sparse even if the distance increases, and a scan density above a certain density is obtained. A specific scan density is determined by the calculation accuracy of the trough portion of the spiral target, but it is preferable to experimentally find it in advance so as to obtain the required accuracy. As a guideline, the scan density is set so that three or more scan points are obtained on the slope forming the spiral.

The horizontal angle calculator 215 calculates the distance L between the trough of the spiral target 120 and the center of reflection P of the omni-reflection prism 110, and calculates the angle Dm ( ) is calculated, and Ht is calculated based on the principle of FIG. A communication unit 216 communicates with an external device such as the terminal 132 in FIG. The specific portion position calculator 217 calculates the position of the specific portion in the helical axis direction of the helical structure of the helical target 120 according to the principle of FIG. In this example, the trough portion of the helical structure is used as this specific portion. The method of determining the location of the trough is described above in connection with FIG. Since the laser scanner unit 300 has already been described with reference to FIG. 1, description thereof will be omitted here.

(Example of processing at terminal 132)
The terminal 132 acquires the position data of the target device 130 and the data of Dm and Ht in FIG. 6 from the surveying instrument 400 . Then, the terminal 132 creates, for example, the image of FIG. 10 and displays it on its own display. Using this image as a reference, the worker moves the target device 130 to a position for piling or surveying. A method for creating the image shown in FIG. 10 will be described below.

FIG. 10 shows an example of a screen display in which the upper direction is the front of the target device 130 . First, the current position of the target device 130 in the absolute coordinate system is precisely measured by the TS function unit 200 and the data is obtained from the surveying instrument 400 . Moreover, the target position (the position where the pile is driven) is specified on the drawing in advance, and the data thereof is also acquired. The front direction Ht (see FIG. 6) of the target device 130 in the absolute coordinate system is calculated on the surveying instrument 400 side.

Therefore, the current position of the target device 130, the target position, and the direction of the front of the target device 130 in the absolute coordinate system are entered on the map software, and based on Ht, the display screen is rotated so that the top is the front, and based on Dm , the direction of the surveying instrument 400 is displayed, and the screen of FIG. 10 is obtained.

Since Dm in FIG. 10 is not obtained from a magnetic sensor, a gyro sensor, or a GPS sensor, the problem of reduced accuracy mentioned in the problem column is avoided.

FIGS. 11A and 11B show another example of the guide display on the display of the terminal 132 during piling work.

(Example of processing)
An example of surveying processing using the surveying instrument 400 will be described below. FIG. 9 is a flow chart showing the procedure of this process. An operation program related to the processing in FIG. 9 is stored in the storage unit 210 and executed by the arithmetic control unit 212 in FIG. A configuration in which the operating program is stored in an appropriate storage area or storage medium is also possible. It is also possible to store this operation program in an external server or the like and provide it from there.

Here, with reference to FIG. 1, an example of the procedure of processing in the case of performing piling work at a civil engineering construction site will be described. First, an operator places the target device 130 vertically at a certain place (initial position) (step S101). Here, a spirit level is arranged on the target device 130, and the worker uses it to bring the tip of the rod-like member 131 into contact with the ground while keeping the target device 130 vertical.

Next, the all-around reflection prism 110 is tracked using the automatic target tracking function of the TS function unit 200, and the position of the all-around reflection prism 110 is measured by the TS function unit 200 (step S102). Next, using the laser scanner unit 300, laser scanning is performed on a vertical line that intersects the optical axis of the distance measuring light of the TS function unit 200 (step S103). At this time, scanning conditions are set such that a specific or higher scanning density is obtained along the spiral axis of the spiral target 120 .

Next, the position on the vertical line of the trough of the helical structure of the helical target 120 is specified according to the principle of FIG. 7 (step S104). This process is performed by the specific portion position calculator 217 that calculates the position of the specific portion in the spiral axis direction of the spiral structure. Next, the difference L between the position P of the center of reflection of the all-around reflecting prism 110 on the vertical line obtained in step S102 and the position of the valley obtained in step S104 is obtained, and from the relationship shown in FIG. to the surveying instrument 400 (step S105). At this time, Ht is also calculated. The processing of steps S104 and S105 is performed by the horizontal angle calculator 215 .

Once Dm and Ht are obtained, they are sent to terminal 132 . The terminal 132 that receives the information of Dm and Ht creates, for example, the display contents of FIG. 10 and displays it on the display of the terminal 132 (step S106). The operator sees the display in FIG. 10 and moves the target device 130 to the target position.

2. Second Embodiment FIG. 12 shows an example in which the present invention is applied to a technique of projecting an image from a projector to a positioning position (for example, Japanese Patent No. 6130078). In this case, information on the height of the projector from the projection plane (for example, the floor) and the orientation of the projector in the horizontal direction are necessary in order to set the size and orientation of the image to be projected appropriately.

In the case of FIG. 12, the three-dimensional position (horizontal position and height) of a projector 520 equipped with a communication device is obtained by positioning the total reflection prism 110 by the surveying instrument 400, which is installed at a known position and whose reference orientation has been determined. is identified. On the other hand, from the relationship between the position of the total reflection prism 110 positioned by the TS function unit 200 and the position of the trough of the spiral obtained by laser scanning the spiral target 120 from the laser scanner unit 300, the horizontal position of the projector 520 is determined. An orientation in the direction is specified.

Information about the three-dimensional position and horizontal orientation of the projector 520 is calculated by the survey instrument 520 and sent to the projector 520 . Upon receiving this information, the projector 520 adjusts the image to be projected, its projection position, and the scale and orientation of the projected image.

3. Third Embodiment For example, the present invention can also be used for a technique for identifying the horizontal direction of a moving object. In this case, a target obtained by coupling the omni-reflection prism 110 and the spiral target 120 in the vertical direction is fixed to the moving object. At this time, the target is fixed to the moving body so that the helical axis is vertical. For example, a gimbal mechanism is used so that the helical axis of the target is always vertical even if the moving body is tilted. Note that in the case of a structure in which the target tilts together with the moving body, the rotation of the moving body about the yaw axis is detected.

In FIG. 13, a UAV (Unmanned Aerial Vehicle) 500 is attached with a target device 510 in which a total reflection prism 110 and a spiral target 120 are combined via a gimbal mechanism 501. The case of detecting orientation in the horizontal direction is shown.

In this case, the surveying instrument 400 is horizontally installed at a position whose coordinates are known in the absolute coordinate system, and the azimuth in the horizontal direction in the absolute coordinate system is determined. Then, the total reflection prism 110 in the flying UAV 500 is tracked and positioned by the TS function unit 200 . Further, the horizontal angle (corresponding to Dm in FIG. 6) of the UAV 500 with respect to the surveying instrument 400 is obtained according to the principle explained in the first embodiment by laser scanning the helical target 120 in the helical axis direction by the laser scanner unit 300 . Also, the horizontal angle Ht of the UAV 500 in the absolute coordinate system is obtained according to the principle of FIG.

4. Fourth Embodiment Directional detection with a helical target is not limited to the horizontal direction. For example, the surveying instrument 400 shown in FIG. 1 is laid down 90 degrees and used. In this case, the target device 130 is also turned horizontally by 90° and used. In this case, the angle around the horizontal axis (elevation angle) of the target device 130 can be measured.

5. Fifth Embodiment It is also possible to detect the rotation angle only with a spiral target without using a reflecting prism. A spiral target 120 is shown in FIG. In this case, by performing a laser scan in the vertical direction aiming at the spiral axis of the spiral target 120, the point cloud data of the peaks and valleys of the spiral and the flat portion (the portion of the outer peripheral surface of the cylinder or cylinder) can be obtained according to the principle of FIG. get.

Then, based on this point cloud data, L (L1) in FIG. 16 is obtained. For the starting point of L, select a structural portion that can be identified as the BTM and whose position on the helical axis does not change even when the helical target 120 is rotated. In the example of FIG. 16, the starting point of L is the boundary portion between the helical structure and the non-helical structure, and the distance from there to the trough position (BTM) of the helical structure is the measured value of L.

Since L depends on the rotation angle Dm of the helical target 120, Dm can be obtained by obtaining L. This example can be regarded as a case where the reference for quantitatively evaluating the position of the trough of the helical structure is the lower end portion of the helical target 120 .

It is also possible to acquire the distance La of the flat portion in the direction of the spiral axis from the laser scan data of the flat portion that can be identified as the peak-valley portion instead of the peak-valley portion of the spiral structure. Since La and Dm have a proportional relationship as shown in FIG. 5, Dm can be obtained by obtaining La.

FIG. 17 shows a case where an annular protrusion 121 is provided at the end of the spiral target 120. As shown in FIG. The annular protrusion 121 does not have a helical structure, and even if the helical target 120 is rotated, the position of the ridge in the direction of the helical axis does not change. Moreover, the height of the crest of the annular protrusion 121 is set to a value different from the height of the crest of the spiral structure, so that it can be distinguished from the spiral structure portion by laser scanning.

Here, when the spiral target 120 rotates, the distance L between the crest position of the annular protrusion 121 and the bottom position BTM of the trough of the spiral structure changes. As in this case and in FIG. 5, the rotation angles Dm and L of the helical target 120 have a specific relationship (in this case also a proportional relationship). Therefore, Dm can be measured by the following procedure. First, the relationship between Dm and L is acquired in advance. In the measurement, laser scanning is performed in the vertical direction aiming at the spiral axis of the spiral target 120, and according to the principle shown in FIG. Ask. Then, the distance L in the spiral axis direction (in this case, the distance in the vertical direction) between the crest position of the annular protrusion 121 and the bottom position BTM of the trough of the spiral structure is calculated, and Dm is calculated from the relationship shown in FIG. get

(Other 1)
Examples of the waveform shown by the cross-sectional structure of the helical target (the structure of the cross section cut along a plane including the helical axis) include the waveform shown in FIG. 14 . In either case, the relationship between the phase state of the waveform and the rotation angle around the spiral axis must be obtained and known in advance. Waveforms include not only triangular waveforms as in the example of FIG. 4, but also sinusoidal waveforms, sawtooth waveforms, rectangular waveforms, and the like.

A form in which the periodicity of the helical structure has a specific frequency structure and the distribution of laser scanning points is obtained by frequency analysis is also possible. For example, it is possible to adopt a case where the helical structure has a waveform obtained by synthesizing a plurality of different frequencies. In this case, there is a specific relationship between the result of frequency analysis and the rotation angle of the helical structure, which is obtained in advance. Then, the horizontal angle of the helical target is obtained from the result of the frequency analysis.

Although FIG. 5 shows the case where the relationship between L and the horizontal angle of the helical target is linear, it is possible for this relationship to be non-linear instead of linear. Importantly, the relationship between L and the horizontal angle of the helical target is specified in advance and is known information.

(Other 2)
FIG. 4 shows an example focusing on the position of the trough of the helical structure, but it is also possible to focus on the top of the mountain. In this case, the distance L between the position of the crest of the spiral target 120 and the position of the center of reflection of the omni-reflecting prism 110 is used.

(Other 3)
As the laser scanner unit 300, it is also possible to use a configuration that simultaneously irradiates a plurality of scan beams in a fan shape in the horizontal direction (horizontal direction). In this case, one of the laser scanning beams is irradiated within a vertical plane including the optical axis of the telescope 16 (the optical axis of the distance measuring beam).

In this example, laser scanning along the vertical plane (laser scanning in the vertical direction) is performed not only in one line but also in left and right oblique directions at the same time.

For example, consider laser scanning light (laser scanning light with an elevation angle of 0°) horizontally emitted from the surveying instrument 400 at a certain timing. Here, it is assumed that the horizontal angle viewed from the surveying instrument 400 is measured with the front as a reference (0°), the right direction as +, and the left direction as -. Then, it is assumed that seven laser scanning beams are simultaneously irradiated at intervals of 2°. In this case, seven laser scanning beams are simultaneously irradiated in the direction of a fan-shaped range of horizontal angles of -6°, -4°, -2°, 0°, +2°, +4°, and +6°. Note that this is just an example, and the number of laser scanning beams irradiated at the same time and their angular relationship are not limited to the above case.

(Other 4)
A configuration in which the TS function unit 200 is not used is also possible. In this case, the positioning of the total reflection prism 110 is performed by the laser scanner unit 300 . Positioning of the all-around reflection prism 110 by the laser scanner unit 300 will be described below.

In this case, first, a laser scan is performed on an area including the all-around reflecting prism 110 . Since the reflected light from the all-around reflection prism 110 is relatively strong, the scan point with the strongest reflected light is extracted from the obtained scan points, and that scan point is used as the all-around reflection prism. 110 is identified as the center of reflection.

During laser scanning, if the reflected light from the omnidirectional reflection prism 110 is too strong and the input resistance of the light receiving element of the laser scanner unit is exceeded, the emission intensity of the laser scanning or scanning light through a neutral density filter may be reduced. Deal with it by dropping it.

(Other 5)
The separation distance between P and BTM in the three-dimensional space can also be adopted as L in FIG. In this case, where the coordinates of BTM are (x ₁ , y ₁ , z ₁ ) and the coordinates of P are (x ₂ , y ₂ , z ₂ ), L = ((x ₁ -x ₂ ) ² +(y ₁ - Calculate L by y ₂ ) ² +(z ₁ −z ₂ ) ² ) ^1/2 .

(Other 6)
The helical target 120 has a cylindrical or columnar shape with a helical structure on the outer circumference, but the cross-sectional shape taken in a direction perpendicular to the helical axis is not limited to a circle, but an ellipse, a polygon, or a polygon with rounded corners. etc. is also possible.

INDUSTRIAL APPLICABILITY The present invention is applicable to techniques for measuring the orientation of an object.

11... Horizontal rotating part, 12... Pedestal, 13... Vertical rotating part, 14a... Horizontal rotation angle control dial, 14b... Elevation angle control dial, 15a... Sighting device, 15b... Sighting device 15b, 16... Telescope, 17... Eyepiece Parts 18, 19... Display 110... Total reflection prism 120... Spiral target 130... Target device 131... Rod-shaped member 132... Terminal 200... TS function part 300... Laser scanner part 301... Third 1 tower section, 302 ... second tower section, 303 ... coupling section, 304 ... protective case, 305 ... rotating section, 306 ... oblique mirror, 400 ... surveying instrument, 500 ... UAV 501 ... gimbal mechanism, 510 ... target device.

Claims (2)

a spiral target having a spiral uneven structure on its surface;
a reflective prism positioned on the helical axis of the helical target;
L is the distance between the position of the specific portion of the helical concave-convex structure and the position of the center of reflection of the reflecting prism when viewed from a specific direction, and the rotation of the helical target about the helical axis with respect to a reference rotational position With the angle θ,
A target device in which the relationship between said L and said θ is acquired in advance. a spiral target having a spiral uneven structure on its surface;
A surveying method for surveying a target device comprising a reflecting prism arranged on the spiral axis of the spiral target with a surveying instrument,
The surveying device includes a functional unit that performs positioning using ranging light and a laser scanner unit that performs laser scanning,
L is the distance between the position of the specific portion of the spiral concave-convex structure and the position of the reflection center of the reflecting prism when viewed from a specific direction, and the rotation of the spiral target about the spiral axis with respect to a reference rotational position With the angle θ,
The relationship between the L and the θ is obtained in advance,
measuring the position of the reflecting prism by positioning using the ranging light of the surveying device;
Measuring the position of the specific part by laser scanning using the laser scanner unit of the surveying instrument,
calculating the distance between the measured position of the reflecting prism and the measured position of the specific portion;
A surveying method for obtaining a rotation angle of the target device about the spiral axis with respect to the reference rotation position based on the calculated distance and the relationship between the L and the θ obtained in advance.

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