Surveying system, surveying method, and surveying program

Abstract

To provide a surveying system, a surveying method, and a surveying program for increasing measurement precision of a measurement point.SOLUTION: In a surveying system 1 that has a target device 3 having a pole 14, and a target 15 in which distance from a low end of the pole is known, and a surveying device 2 capable of measuring the target, a lower end of the pole is allowed to match a predetermined measurement point 13, and the surveying device calculates an O-M vector for connecting a machine center of the surveying device and a measurement position of the target, and an M-P vector for connecting the measurement position and the measurement point, calculates an angle φ between a plane that is orthogonal to the M-P vector and passes the measurement position and the O-M vector, calculates a measurement error between the measurement position and an optical center of the target on the basis of the angle φ, corrects the measurement position on the basis of the measurement error, and calculates three-dimensional coordinates of the measurement point on the basis of the corrected measurement position.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a surveying system, a surveying method, and a surveying program capable of measuring the three-dimensional coordinates of a desired measurement point. [Background technology]

[0002] When surveying a desired measurement point, the survey is generally carried out using a prism having retroreflective properties, etc. In prism surveying using a prism, for example, a pole with a prism at a known position is installed at the measurement point, and the prism is leveled so that it is positioned vertically above the measurement point via a bubble tube, etc., and then the prism is measured using a surveying device such as a total station.

[0003] However, when prism measurement is performed at a plurality of measurement points, it is necessary to carry out leveling each time the measurement point is moved, which takes time for measurement and reduces workability.

[0004] In addition, when the measurement point is a corner of a room, the pole cannot be vertically aligned, and when the prism cannot be placed vertically above the measurement point, it is difficult to perform a survey using the prism.

[0005] Furthermore, there is a surveying instrument that is equipped with an inclination angle detector on the pole, detects the inclination angle of the pole using the inclination angle detector, and corrects the measurement value based on the detected inclination angle, making it possible to measure the corners of a room, etc. However, this surveying instrument has the risk of producing errors in the measurement results depending on the direction of inclination. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6721479 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention provides a surveying system, a surveying method, and a surveying program that improve the measurement accuracy of measurement points. [Means for solving the problem]

[0008] The present invention relates to a surveying system having a target device having a pole and a target whose distance from the bottom end of the pole is known, and a surveying instrument capable of measuring the target, wherein the bottom end of the pole is aligned with a predetermined measurement point, the surveying instrument calculates an OM vector connecting the instrument center of the surveying instrument and the measurement position of the target, and an MP vector connecting the measurement position and the measurement point, calculates the angle φ between the OM vector and a plane that is perpendicular to the MP vector and passes through the measurement position, calculates the measurement error between the measurement position and the optical center of the target based on the angle φ, corrects the measurement position based on the measurement error, and calculates the three-dimensional coordinates of the measurement point based on the corrected measurement position.

[0009] The present invention also relates to a surveying system configured so that the target device swings the pole while aligning the lower end of the pole with a predetermined measurement point, the surveying instrument measures the target at at least three points, calculates three-dimensional coordinates of a virtual measurement point based on the measurement positions of each target, and calculates the MP vector based on the measurement positions of the target and the virtual measurement point.

[0010] The present invention also relates to a surveying system in which the target device further has an inclination sensor, and the surveying device is configured to calculate the MP vector based on the measurement position and the attitude of the pole detected by the inclination sensor.

[0011] The present invention also relates to a surveying system configured such that the surveying instrument calculates the degree of coincidence between the measurement point and the virtual measurement point as an accuracy, and when the accuracy meets a preset threshold value, corrects the measurement position of each target, recalculates the virtual measurement point as a measurement point based on each corrected measurement position, and performs an operation to complete the measurement.

[0012] The present invention also relates to a surveying system in which the surveying instrument corrects all measurement positions of the target each time the virtual measurement point is calculated, recalculates the virtual measurement point based on the corrected measurement positions, calculates the degree of agreement between the measurement point and the virtual measurement point as an accuracy, and when the accuracy meets a preset threshold value, regards the virtual measurement point as a measurement point and performs an operation to complete the measurement.

[0013] The present invention also relates to a surveying system in which the surveying instrument is configured to calculate the distance from the bottom end of the pole to the target as the radius, calculate the center of a sphere fitting to each measurement position as the measurement point, calculate a reference sphere normalized with the radius of the sphere being 1, calculate the area of ​​the smallest curved surface that includes all the points on the surface of the reference sphere, and calculate the accuracy based on a comparison between the curved surface and a preset reference curved surface.

[0014] The present invention also relates to a surveying system in which the surveying instrument further has a tracking function and is configured so as to be able to measure the target while tracking it.

[0015] The present invention also relates to a surveying system configured such that, each time the surveying device measures the target, it sequentially calculates a sphere fitting to the measurement positions of at least three consecutively measured targets, and determines whether the target device has been installed at the measurement point based on whether the distance between the centers of each sphere converges within a predetermined threshold range.

[0016] The present invention also relates to a surveying method having the steps of: calculating, with the lower end of the pole aligned with a predetermined measurement point, an OM vector connecting the instrument center of the surveying instrument and the measurement position of a target provided at the upper end of the pole, and an MP vector connecting the measurement position and the measurement point; calculating the angle φ between the OM vector and a plane that is perpendicular to the MP vector and passes through the measurement position; calculating the measurement error between the measurement position and the optical center of the target based on the angle φ; correcting the measurement position based on the measurement error; and calculating the three-dimensional coordinates of the measurement point based on the corrected measurement position.

[0017] The present invention also relates to a surveying method which further comprises the steps of swinging the pole while aligning the lower end of the pole with a predetermined measurement point, measuring the target at at least three points, calculating three-dimensional coordinates of a virtual measurement point based on the measurement positions of each target, and calculating the MP vector based on the measurement positions of the target and the virtual measurement point.

[0018] The present invention also relates to a surveying method further comprising the steps of receiving the attitude of the pole from an inclination sensor provided on the pole, and calculating the MP vector based on the received attitude of the pole.

[0019] Furthermore, the present invention relates to a surveying program that causes the surveying instrument to execute the following processes while aligning the bottom end of the pole with a specified measurement point: calculating an OM vector connecting the instrument center of the surveying instrument and the measurement position of a target attached to the top end of the pole, and an MP vector connecting the measurement position and the measurement point, calculating the angle φ between the OM vector and a plane that is perpendicular to the MP vector and passes through the measurement position, calculating the measurement error between the measurement position and the optical center of the target based on the angle φ, correcting the measurement position based on the measurement error, and calculating the three-dimensional coordinates of the measurement point based on the corrected measurement position. Effect of the Invention

[0020] According to the present invention, a surveying system having a target device having a pole and a target whose distance from the bottom end of the pole is known, and a surveying instrument capable of measuring the target, is configured to align the bottom end of the pole with a predetermined measurement point, and the surveying instrument calculates an OM vector connecting the instrument center of the surveying instrument and the measurement position of the target, and an MP vector connecting the measurement position and the measurement point, calculates an angle φ between the OM vector and a plane that is perpendicular to the MP vector and passes through the measurement position, calculates a measurement error between the measurement position and the optical center of the target based on the angle φ, corrects the measurement position based on the measurement error, and calculates three-dimensional coordinates of the measurement point based on the corrected measurement position.Therefore, even if a measurement error exists between the measurement position of the target measured by the surveying instrument and the optical center of the target, the measurement error can be corrected, and the measurement accuracy of the measurement point can be improved.

[0021] In addition, according to the present invention, with the bottom end of the pole aligned with a specified measurement point, the process includes the steps of calculating an OM vector connecting the instrument center of the surveying instrument and the measurement position of a target attached to the top end of the pole, and an MP vector connecting the measurement position and the measurement point, calculating the angle φ between the OM vector and a plane that is perpendicular to the MP vector and passes through the measurement position, calculating the measurement error between the measurement position and the optical center of the target based on the angle φ, correcting the measurement position based on the measurement error, and calculating the three-dimensional coordinates of the measurement point based on the corrected measurement position.Therefore, even if a measurement error exists between the measurement position of the target measured by the surveying instrument and the optical center of the target, the measurement error can be corrected, and the measurement accuracy of the measurement point can be improved.

[0022] Furthermore, according to the present invention, with the bottom end of the pole aligned with a specified measurement point, the surveying instrument executes the following processes: calculation of an OM vector connecting the instrument center of the surveying instrument and the measurement position of a target attached to the top end of the pole, and an MP vector connecting the measurement position and the measurement point, calculation of the angle φ between the OM vector and a plane that is perpendicular to the MP vector and passes through the measurement position, calculation of the measurement error between the measurement position and the optical center of the target based on the angle φ, correction of the measurement position based on the measurement error, and calculation of the three-dimensional coordinates of the measurement point based on the corrected measurement position. Therefore, even if a measurement error exists between the measurement position of the target measured by the surveying instrument and the optical center of the target, the measurement error can be corrected, and the measurement accuracy of the measurement point can be improved. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram showing a surveying system according to a first embodiment. [Diagram 2] 1 is a schematic block diagram showing a surveying instrument according to a first embodiment. [Diagram 3] FIG. 1A is an explanatory diagram showing the swinging of the target device, and FIG. 1B is an explanatory diagram showing a sphere that is fitted to the measurement results. [Figure 4] FIG. 4 is an explanatory diagram for explaining a method for determining accuracy of a measurement point according to the first embodiment. [Diagram 5] FIG. 4 is an explanatory diagram for explaining a measurement position and an optical center position according to the first embodiment. [Figure 6] 4 is a flowchart for explaining measurement by the survey system according to the first embodiment. [Figure 7] 10 is a flowchart for explaining measurement by a survey system according to a second embodiment. [Figure 8] FIG. 11 is a schematic diagram showing a surveying system according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0025] First, a surveying system according to a first embodiment of the present invention will be described with reference to FIG.

[0026] The surveying system 1 has a surveying device 2 and a target device 3. The surveying device 2 is, for example, a total station with a tracking function, and is composed of a leveling unit 5 attached to a tripod 4, and a surveying device main body 6 attached to the leveling unit 5 and capable of horizontally rotating with respect to the leveling unit 5. The surveying device 2 is installed at a reference point having known three-dimensional coordinates.

[0027] The leveling unit 5 has a sensor (not shown) for detecting the inclination of the leveling unit 5 and a motor (not shown) for driving a leveling screw that levels the leveling unit 5, and is configured to automatically level the leveling unit 5 based on the detection results of the sensor.

[0028] The surveying instrument main body 6 has a telescope unit 7 that can rotate vertically relative to the surveying instrument main body 6. The telescope unit 7 also incorporates a distance measuring unit 8 (described later) and a tracking unit 9 (described later). The distance measuring unit 8 is configured to emit a distance measuring light 11 on a distance measuring optical axis, and measure the distance to the object to be measured based on the reflected distance measuring light reflected by the object to be measured. The tracking unit 9 is configured to emit a tracking light 12 on a tracking optical axis (on the distance measuring optical axis) that is coaxial with the distance measuring light 11, and perform tracking based on the reflected tracking light reflected by the object to be measured.

[0029] The target device 3 has a rod-shaped pole 14 installed at the measurement point 13, and a prism 15 as a target (measurement object) provided at the upper end of the pole 14. The lower end of the pole 14 is cone-shaped with a diameter decreasing downward, and the lower end is a pointed end. The prism 15 is, for example, a 360° full-circumference prism combining a plurality of retroreflection prisms 15a to 15n. The optical center of the prism 15 is located on the axis of the pole 14, and the distance from the lower end of the pole 14 to the optical center of the prism 15 is known. In FIG. 1, a cross section of the prism 15 is shown as the prism 15.

[0030] Next, the configuration of the surveying instrument 2 will be described with reference to FIG.

[0031] The surveying instrument 2 has a horizontal rotation drive unit 16 for rotating the surveying instrument main body 6 relative to the leveling unit 5, a horizontal angle detector 17 for detecting the rotation angle (horizontal angle) of the surveying instrument main body 6, a vertical rotation drive unit 18 for rotating the telescope unit 7 relative to the surveying instrument main body 6, and a vertical angle detector 19 for detecting the rotation angle (vertical angle) of the telescope unit 7. The surveying instrument 2 also has an arithmetic and control unit 21, a memory unit 22, a display unit 23, and an operation unit 24.

[0032] Furthermore, the horizontal rotation drive unit 16 and the vertical rotation drive unit 18 constitute the drive unit of the surveying instrument 2, and the horizontal angle detector 17 and the vertical angle detector 19 constitute an angle measurement unit for detecting the irradiation direction of the distance measuring light 11.

[0033] A CPU specialized for this embodiment, or a general-purpose CPU, an embedded CPU, a microprocessor, etc., is used as the arithmetic control unit 21. Furthermore, a semiconductor memory such as a RAM, a ROM, a Flash ROM, or a DRAM, a magnetic memory such as a HDD, an optical memory such as a CD-ROM, etc. are used as the storage unit 22.

[0034] The memory unit 22 stores a sequence program for controlling a measurement operation, a distance measurement program for calculating a distance by a distance measurement operation, an angle measurement program for calculating the irradiation direction (angle) of the distance measurement light 11 and the tracking light 12 based on the detection results of the horizontal angle detector 17 and the vertical angle detector 19, a measurement program for calculating three-dimensional coordinates of the prism 15 based on the distance and angle, a leveling program for causing the leveling unit 5 to perform leveling, a tracking program for causing the tracking unit 9 to track the prism 15, and a program for calculating three-dimensional coordinates of a virtual measurement point based on measurement results (distance measurement results and angle measurement results) of at least three different points of the prism 15. Various programs are stored in the memory, such as a calculation program for calculating the accuracy of the virtual measurement point 13 based on the horizontal rotation drive unit 16, a calculation program for calculating the degree of coincidence between the virtual measurement point 13 and the measurement point 13 as an accuracy, a judgment program for judging whether the calculated accuracy satisfies a preset threshold value, a correction program for correcting the calculation result (three-dimensional coordinates) of the virtual measurement point, a calculation program for calculating the three-dimensional coordinates of the measurement point 13 based on the corrected virtual measurement point, a notification program for notifying of the completion of measurement, a drive control program for controlling the horizontal rotation drive unit 16, the vertical rotation drive unit 18, etc., and a display program for displaying the measurement results, etc. on the display unit 23.

[0035] The storage unit 22 also stores measurement data (distance measurement data and angle measurement data) obtained when the prism 15 is measured, three-dimensional coordinate data of the measurement point 13 calculated based on the measurement data, and other data. Also stored are a threshold value for determining the accuracy of the center position of the sphere relative to the measurement point 13, which will be described later, and an approximate formula for correction. The accuracy indicates how well the position of a virtual measurement point 13a determined by calculation matches the measurement point 13, that is, the degree of agreement between the measurement point 13 and the virtual measurement point 13a. The calculation control unit 21 deploys and executes various programs stored in the storage unit 22, and executes various processes.

[0036] Next, measurement using the surveying system 1 will be described with reference to the flowcharts of FIGS. 3(A), 3(B), 4, 5 and 6. FIG.

[0037] STEP 01 First, the arithmetic and control unit 21 causes the telescope unit 7 to collimate the prism 15 and start measuring and tracking the prism 15.

[0038] The surveying device 2 measures the prism 15 (distance measurement, angle measurement) at a predetermined interval, for example, 20 Hz, while tracking the prism 15. Therefore, three-dimensional coordinates (point cloud) of a plurality of points along the trajectory 25 of the prism 15 are obtained. The measurement interval is not limited to 20 Hz, and an appropriate interval such as 10 Hz, 30 Hz, etc. can be selected.

[0039] In the measurement of the prism 15, there may be a mismatch between the timing of measuring the distance and the timing of measuring the angle for the prism 15. In this case, the measurement accuracy of the prism 15 can be improved by discarding the measurement results with the mismatched timing.

[0040] STEP: 02 With the surveying device 2 tracking the prism 15, the operator carries the target device 3 toward the predetermined measurement point 13.

[0041] STEP:03 The distance (offset length R) from the lower end of the pole 14 to the optical center of the prism 15 is known. The calculation control unit 21 calculates a sphere 26 with a radius of the offset length R, and fits the sphere 26 to a group of at least three consecutive points set in advance. As shown in FIG. 3(B), for example, when fitting the sphere 26 based on four points, in the nth measurement, the sphere 26 is fitted to four points: the prism 15n measured in the nth measurement, the prism 15n-1 measured in the n-1th measurement, the prism 15n-2 measured in the n-2th measurement, and the prism 15n-3 measured in the n-3th measurement, three times before. That is, the sphere 26 is fitted to the four points measured in succession in sequence.

[0042] Alternatively, the calculation control unit 21 calculates the sphere 26, which has a radius equal to the offset length R and passes through the three-dimensional coordinates of the measured four points of the prisms 15n, 15n-1, 15n-2, and 15n-3.

[0043] Moreover, the calculation control unit 21 sequentially calculates the sphere 26 that is fitted to four points and also calculates the center of the sphere 26 every time the prism 15 is measured.

[0044] STEP 04: The calculation control unit 21 judges whether the sphere 26 that fits the four points exists, and whether the distance between the centers of the spheres 26 that are sequentially calculated converges to a preset threshold value or less.

[0045] If the sphere 26 fitting to the four points cannot be calculated, or if the successively calculated centers of the sphere 26 do not converge to the threshold value or less, the calculation control unit 21 determines that the target device 3 is moving and discards the measurement results. After discarding the measurement results, calculation of the sphere 26 and calculation of the center of the sphere 26 are continued.

[0046] Furthermore, if a sphere 26 exists that fits the four points and the center of the sphere 26 converges below a predetermined threshold value, the calculation control unit 21 determines that the target device 3 is installed at the measurement point 13, i.e., the lower end of the pole 14 coincides with the measurement point 13.

[0047] STEP: 05 After setting up the target device 3, the worker swings the target device 3 at a predetermined angle in a predetermined direction with the lower end of the pole 14 aligned with the measurement point 13. For example, as shown in Fig. 3(A), the target device 3 is swung in a cross shape by ±15°.

[0048] The swing of the target device 3 is not limited to a cross shape, and for example, the target device 3 may be tilted so that the prism 15 draws a circle, or the target device 3 may be tilted so that the prism 15 draws a figure eight. Furthermore, the prism 15 may be tilted to draw a triangular trajectory and pass through one point in the triangle. That is, it is sufficient that the swing direction has a two-dimensional spread. Furthermore, the tilt angle of the target device 3 is not limited to ±15°, and may be greater than 15° or less than 15°.

[0049] From the time when it is determined that the target device 3 is placed at the measurement point 13, the arithmetic and control unit 21 sequentially stores and accumulates the measurement results of the prism 15 as a point cloud in the storage unit 22.

[0050] STEP 06: The calculation control unit 21 calculates the sphere 26 that fits the accumulated point cloud, and calculates the center of the sphere 26, that is, the lower end of the pole 14, as a virtual measurement point 13a.

[0051] STEP: 07 After calculating the virtual measurement point 13a, the calculation control unit 21 calculates the accuracy A of the virtual measurement point 13a. Here, the accuracy A of the virtual measurement point 13a is a value indicating the degree of agreement between the calculated virtual measurement point 13a and the actual measurement point 13.

[0052] 3B, for example, the calculation control unit 21 calculates the accuracy A of the measurement point 13 based on the spread of the measurement results (point cloud) of the prism 15 at four consecutive points on the sphere 26 having the virtual measurement point 13a as the center and the offset length R as the radius. That is, the calculation control unit 21 calculates the accuracy A of the virtual measurement point 13a based on the spread of all the point clouds stored in the memory unit 22 after the target device 3 is installed.

[0053] In the above method, first, the calculation control unit 21 normalizes the sphere 26 to a reference sphere 27 as shown in Fig. 4. The reference sphere 27 is normalized with an offset length R = 1, and is a sphere with a center at the virtual measurement point 13a and a radius of 1. That is, the three-dimensional coordinates of the point cloud obtained by measuring the prism 15 and located on the surface of the sphere 26 are converted into a point cloud 28 located on the surface of the reference sphere 27, centered on the virtual measurement point 13a.

[0054] Next, the calculation control unit 21 calculates the area S of the smallest curved surface 29 that includes all the point group 28 located on the surface of the reference sphere 27. The curved surface 29 is a curved surface that forms a part of the surface of the reference sphere 27. The memory unit 22 stores a reference curved surface 31 for comparison with the area S. The reference curved surface 31 is a curved surface that forms a part of the surface of the reference sphere 27 and has an area B. Here, the area B is a size that allows a desired fitting accuracy to be obtained when the reference sphere 27 is fitted to the point group 28.

[0055] The accuracy A of the virtual measurement point 13a can be expressed as accuracy A = area S / area B. The calculation control unit 21 calculates the accuracy A of the virtual measurement point 13a based on the area S of the curved surface 29 and the area B of the reference curved surface 31.

[0056] STEP:08 When the accuracy A of the virtual measurement point 13a is calculated, the calculation control unit 21 judges whether the accuracy A of the virtual measurement point 13a satisfies a predetermined threshold, for example, whether it is 1 or more. That is, the calculation control unit 21 judges whether the area S is equal to or larger than the area B. When the accuracy is 1 or more, it can be judged that the reference sphere 27 has been fitted to the point cloud 28 with a desired fitting accuracy.

[0057] If it is determined that the accuracy A is less than 1, i.e., the size of the area S is smaller than the area B and does not satisfy the threshold value, the target device 3 is swung more to increase the area S, and the processes of STEP: 05 to STEP: 08 are executed again. That is, every time a measurement of the prism 15 is performed, fitting of the sphere 26 is executed for each measurement result, and the calculation of the virtual measurement point 13a and fitting of the sphere 26 are repeated until the accuracy becomes 1 or more.

[0058] An alarm may be used to notify the worker whether the certainty A has met the threshold value. For example, the sound may be made lower as the certainty A becomes farther from 1 and higher as the certainty A becomes closer to 1, or the sound may be generated intermittently, with the interval between sounds being wider as the certainty A becomes farther from 1 and narrower as the certainty A becomes closer to 1. Alternatively, a light may be made to flash, with the frequency of the flashing increasing as the certainty A becomes farther from 1 and the frequency of the flashing decreasing as the certainty A becomes closer to 1, or the color of the light may be changed when the certainty A becomes 1.

[0059] Also, as an alarm, the value of area S / area B may be displayed as a percentage on the display unit 23, and when area S / area B≦1, it may become 100%. Furthermore, as an alarm, when the accuracy A meets a threshold value, the process may simply proceed to the next step, or the measurement result may be displayed on the display unit 23. It goes without saying that various measurement completion actions such as sound, light, display, etc. may be combined.

[0060] STEP:09 If it is determined that the accuracy A is 1 or more, that is, the size of the area S is equal to or larger than the area B and satisfies the threshold value, the calculation control unit 21 determines that the virtual measurement point 13a coincides or approximately coincides with the measurement point 13, and performs a correction for the measurement point 13.

[0061] 5, the measurement position M measured as the center of the prism 15 by the surveying instrument 2 does not necessarily coincide with the actual center position (optical center) M' of the prism 15. For example, when the apparent direction of the prism 15 changes, the incident position of the distance measuring light 11 to the prism 15 also changes, so that a deviation (measurement error) occurs between the reflection position of the distance measuring light 11 in the prism 15, i.e., the measurement position M and the center position M' of the prism 15.

[0062] If the instrument center of the surveying instrument 2 installed at the reference point is O, the measurement position of the prism 15 measured by the surveying instrument 2 is M, the position of the actual center (optical center) of the prism 15 is M', and the calculated virtual measurement point 13a, i.e., the position of the tip (lower end) of the pole 14, is P, the direction vector connecting the instrument center O and the measurement position M is the OM vector 32, the direction vector connecting the measurement position M and the measurement point P is the MP vector 33, and the direction vector connecting the measurement position M and the prism center M' is the MM' vector 34. Note that the three-dimensional coordinates of the reference point are known, and the height of the surveying instrument 2, i.e., the height of the instrument center O, is also known, so the three-dimensional coordinates of the instrument center O are known. Also, the inclination of the OM vector 32 can be calculated based on the three-dimensional coordinates of the instrument center O and the measurement position M, and the MP vector 33 can be calculated based on the three-dimensional coordinates of the measurement position M and the measurement point P.

[0063] In this case, if the angle between the OM vector 32 and a plane that is perpendicular to the MP vector 33 and passes through the measurement position M is φ, and the angle between the OM vector 32 and the MP vector 33 is θ, the angle φ can be calculated as φ=90°-θ.

[0064] The calculation control unit 21 calculates the distance (measurement error) between the measurement position M and the prism center M' based on the angle φ, that is, the measurement error Δe in the direction of the MP vector 33. As a method for calculating Δe, for example, the method for calculating the measurement error shown in Patent Document 1 can be used.

[0065] When there is a difference in height between the surveying instrument 2 and the prism 15, which has a structure in which rotation in the axial direction of the pole 14 is fixed, the measurement error Δe is uniquely determined by the angle φ, the size of the prism 15, the refractive index of the prism 15, the inclination angle with respect to the entrance surface of the prism 15, and the horizontal distance between the apex of each retroreflective prism 15a to 15n and the optical center M' of the prism 15.

[0066] On the other hand, parameters other than the angle φ can be obtained from the specifications of the prism 15 used and can be substituted, so the measurement error Δe of the prism 15 can be expressed as a function of the angle φ only, i.e., Δe = e(φ).

[0067] The measurement error Δe can be divided into a horizontal measurement error Δd and a vertical measurement error Δh. Here, it is known that the measurement error Δh is approximately proportional to the magnitude of the angle φ, and the measurement error Δh can be approximated by a linear function of the angle φ. It is also known that the measurement error Δd is approximately equal to a quadratic function of the angle φ, and the measurement error Δd can be approximated by a quadratic function of the angle φ.

[0068] Furthermore, Δd and Δh depend on the specifications of the prism 15, such as the size and refractive index, the inclination angle of the incident surface of the prism 15 with respect to the optical axis of the distance measuring light, and the angle φ. Therefore, by calculating an approximation formula for the measurement error Δd and the measurement error Δh in advance based on the specifications of the prism 15 and storing it in the memory unit 22, the measurement error Δd and the measurement error Δh can be easily calculated based on the approximation formula. The calculation control unit 21 calculates the measurement error Δd and the measurement error Δh based on the approximation formula, and calculates the measurement error Δe based on the measurement error Δd and the measurement error Δh.

[0069] When the measurement error Δe is calculated, the calculation control unit 21 corrects the measurement results (three-dimensional coordinates) by the measurement error Δe in the direction of the MP vector 33 for all the measurement results of the point cloud 28 stored and accumulated in the memory unit 22, i.e., for all the measurement positions M, and updates the three-dimensional coordinates of the measurement positions M. The updated measurement positions M are saved in the memory unit 22 as the three-dimensional coordinates of the optical center M'. The three-dimensional coordinates of the measurement positions M are not overwritten by the three-dimensional coordinates of the optical center M'. That is, the memory unit 22 stores the measured three-dimensional coordinates of the measurement positions M and the corrected and updated three-dimensional coordinates of the optical center M'.

[0070] STEP 10: The calculation control unit 21 calculates the sphere 26 that fits to each corrected measurement position M, i.e., each optical center M', and recalculates the center of the sphere 26 as the three-dimensional coordinates of the virtual measurement point 13a. The calculated three-dimensional coordinates of the virtual measurement point 13a are stored in the memory unit 22 as the measurement point 13.

[0071] The calculated measurement point 13 is calculated in the same manner as the virtual measurement point 13a in STEP:06. However, since it is determined in STEP:08 that the accuracy A satisfies the threshold value, the recalculated three-dimensional coordinates of the center of the sphere 26 can be regarded as the three-dimensional coordinates of the measurement point 13.

[0072] STEP 11 When the measurement of the measurement point 13 is completed, the calculation control unit 21 performs an operation to complete the measurement. The operation to complete the measurement may be, for example, to notify the operator of the completion of the measurement by an audible alarm or a light alarm. The above-mentioned alarms may be issued from the surveying device 2 or from an alarm notification mechanism separately provided in the target device.

[0073] If there are other measurement points to be measured based on the alarm notification, the operator repeats the processes in STEP: 02 to STEP: 11. If there are no other measurement points to be measured, the operator ends the measurement process.

[0074] Incidentally, after determining whether or not the accuracy A is satisfied in STEP:08, if the recalculation of the center of the sphere 26 is performed immediately and in a short time, the notification of the measurement completion in STEP:11 may be omitted.

[0075] As described above, in the first embodiment, while the surveying device 2 is tracking and measuring the prism 15, the three-dimensional coordinates of the measurement point 13 can be calculated simply by aligning the lower end of the pole 14 with the measurement point 13 and swinging the target device 3 so as to have a two-dimensional spread.

[0076] Therefore, it is not necessary to level the target device 3 so that the prism 15 is positioned vertically above the measurement point 13, thereby shortening the working time. Also, it is possible to measure the measurement point 13 where the target device 3 cannot be installed vertically, such as on a wall or in a corner of a room, thereby improving the working efficiency.

[0077] In addition, in the first embodiment, the calculation control unit 21 automatically determines whether the target device 3 is installed at the measurement point 13 based on whether a sphere 26 exists that fits at least three points measured in succession and whether the center of the sphere 26 converges.

[0078] Therefore, since there is no need to notify the surveying instrument 2 of the completion of installation every time the target instrument 3 is installed at the measurement point 13, the work time can be shortened and improved.

[0079] When the sphere 26 is fitted to three points, two three-dimensional coordinates of the center of the sphere 26, i.e., the measurement point 13 where the target device 3 is installed, are obtained. On the other hand, when the top and bottom of the prism 15 and the bottom end of the pole 14 are clearly defined, such as when measuring a floor, the three-dimensional coordinates of the measurement point 13 can be uniquely determined.

[0080] Furthermore, in the first embodiment, it is possible to calculate an accuracy indicating the degree to which the virtual measurement point 13a obtained by calculation matches the actual measurement point 13, and only calculation results in which the accuracy satisfies a threshold value (is 1 or greater) are used, thereby enabling measurement of the measurement point 13 with high accuracy.

[0081] In addition, in the first embodiment, a measurement error Δe, which is the amount of deviation between the measurement position M measured by the surveying device 2 and the optical center M' of the prism 15, is calculated based on the specifications of the prism 15 and the angle φ between the OM vector 32 and a plane perpendicular to the MP vector 33, and the measurement result (measurement position M) is corrected based on the measurement error Δe.

[0082] Therefore, the deviation between the measurement position caused by the apparent direction of the prism 15 as seen from the surveying instrument 2 and the optical center of the prism 15 can be corrected, and the calculation accuracy of the center of the sphere 26, i.e., the measurement point 13, can be further improved.

[0083] In the first embodiment, when a start command is input, measurement and tracking are continued even when the target device 3 is moved and installed. On the other hand, it is also possible to perform only tracking of the prism 15 when the target device 3 is moved, and to measure the prism 15 after the target device 3 is installed.

[0084] In addition, in the first embodiment, it is determined whether the target device 3 is moving or has been placed at the measurement point 13 based on whether the sphere 26 exists that fits to a point group of at least three consecutive points, or whether the center of the sphere 26 that is successively fitted to the three points converges to a predetermined threshold value or less each time the prism 15 is measured.

[0085] On the other hand, while tracking the prism 15, the surveying device 2 measures the prism 15 at predetermined time intervals, for example every 2 seconds, and each time the calculation control unit 21 measures the prism 15, it calculates the center of the sphere 26 that fits to the measurement results of at least three consecutive measurements of the prism 15 as the virtual measurement point 13a, and when the accuracy A of the virtual measurement point 13a meets a predetermined threshold, it may be determined that the target device 3 has been installed at the measurement point 13.

[0086] Alternatively, while tracking the prism 15, the surveying device 2 measures the prism 15 at predetermined time intervals, and each time the calculation control unit 21 measures the prism 15, it calculates the center of the sphere 26 that fits to the measurement result a predetermined time ago or a predetermined number of times ago (for example, 5 seconds ago or 5 times ago) as the virtual measurement point 13a, and when the accuracy A of the virtual measurement point 13a meets a predetermined threshold value, it is determined that the target device 3 has been placed at the measurement point 13, and calculates the center of the sphere 26 that fits to the latest measurement result as the measurement point 13.

[0087] In either case, simply by installing the target device 3 at the measurement point 13, measurement of the measurement point 13 is performed automatically, so after installing the target device 3, there is no need to instruct the surveying device 2 to start measurement, improving workability.

[0088] When it is determined that the target device 3 is placed at the measurement point 13, the measurement of the measurement point 13 may be started after a predetermined time has elapsed. That is, after the predetermined time has elapsed, the arithmetic and control unit 21 may perform the processes of STEP: 05 to STEP: 11.

[0089] Furthermore, the calculation of the measurement error Δe in the first embodiment and the correction of the measurement position M using the measurement error Δe can be applied to other embodiments as well. For example, when the target device 3 is leveled in a vertical position, the MP vector 33 becomes a vertical vector, which eliminates the need for calculation, and therefore the measurement error Δe can be easily calculated.

[0090] Next, a second embodiment of the present invention will be described with reference to the flow chart of FIG.

[0091] In FIG. 7, STEP:21 to STEP:26 are similar to STEP:01 to STEP:06 in FIG. 6 of the first embodiment, STEP:27 and STEP:28 are similar to STEP:09 and STEP:10, and STEP:29 to STEP:31 are similar to STEP:07, STEP:08, and STEP:11.

[0092] That is, the timing of correction of the measurement results of the prism 15 (see FIG. 1) and the timing of recalculation of the center of the sphere 26 (see FIG. 3) are different from those in the first embodiment.

[0093] In the second embodiment, the calculation control unit 21 (see FIG. 2) calculates the sphere 26 that fits to the accumulated point cloud 28 (see FIG. 4), and corrects the measurement result (measurement position M) of the prism 15 every time the calculation control unit 21 calculates the center of the sphere 26 as the virtual measurement point 13a (STEP: 27). Moreover, the calculation control unit 21 recalculates the center of the sphere 26 based on the corrected and updated measurement position M, i.e., the optical center M' (STEP: 28).

[0094] After recalculating the center of the sphere 26, the calculation control unit 21 calculates the accuracy A with the calculated center of the sphere 26 as the virtual measurement point 13a (STEP: 29), and judges whether the accuracy A exceeds a predetermined threshold value (STEP: 30). If the accuracy A exceeds the predetermined threshold value, the calculation control unit 21 executes an action to complete the measurement for the operator (STEP: 31), and ends the measurement. If the accuracy A does not exceed the predetermined threshold value, STEP: 25 to STEP: 30 are executed again.

[0095] In the first embodiment, an alarm may be issued after the accuracy A meets a predetermined threshold value, but in the second embodiment, an alarm may be issued as an action to complete measurement.

[0096] In the second embodiment, the three-dimensional coordinates of the measurement point 13 where the pole 14 (see FIG. 1) is installed can be calculated simply by swinging the target device 3 (see FIG. 1). This eliminates the need to level the target device 3, thereby enabling the shortening of work time and the improvement of work efficiency.

[0097] In addition, each time the three-dimensional coordinates of the virtual measurement point 13a are calculated, all measurement results (measurement position M) are corrected and the virtual measurement point 13a is recalculated based on the corrected measurement position, thereby further improving the precision (accuracy) of the virtual measurement point 13a.

[0098] In addition, whether or not the target device 3 has been installed at the measurement point 13 is automatically determined based on whether or not the center of the sphere 26 converges, so there is no need to input the start of measurement and the completion of measurement for each measurement point 13, thereby shortening and improving the work time.

[0099] Furthermore, since the amount of deviation between the measurement position of the prism 15 and the optical center of the prism 15 can be calculated as a measurement error Δe, even if the target device 3 is tilted and the measurement position of the prism 15 is misaligned with the optical center of the prism 15, the three-dimensional coordinates of the optical center of the prism 15 can be obtained, and the measurement accuracy of the measurement point 13 can be further improved.

[0100] Next, a third embodiment of the present invention will be described with reference to Fig. 8. In Fig. 8, the same elements as those in Fig. 1 are given the same reference numerals, and the description thereof will be omitted.

[0101] In the third embodiment, the target device 3 has a tilt sensor 35 provided at the middle of the pole 14. The tilt sensor 35 is, for example, an IMU using an acceleration sensor or a gyro sensor, and is capable of detecting the attitude of the pole 14, i.e., the tilt angle and tilt direction of the pole 14. In addition, the target device 3 has a communication unit (not shown) and is capable of transmitting the tilt angle and tilt direction detected by the tilt sensor 35 to the surveying device 2.

[0102] The surveying device 2 (arithmetic and control unit 21) calculates an OM vector 32 and an MP vector 33 in the same manner as in the first and second embodiments, based on the measurement result of the prism 15 and the tilt angle and tilt direction of the pole 14 received from the target device 3, and calculates an angle φ between the OM vector 32 and a plane that is perpendicular to the MP vector 33 and passes through the measurement position M. In addition, the arithmetic and control unit 21 calculates a measurement error Δe between the measurement position M of the prism 15 measured by the surveying device 2 and the optical center M' of the prism 15, based on the angle φ.

[0103] The calculation control unit 21 displaces the pole 14 downward from the measurement position M along the inclination direction, that is, along the MP vector 33 by Δe from the measurement position M, and calculates the three-dimensional coordinates of the optical center M′.

[0104] In addition, the calculation control unit 21 measures the three-dimensional coordinates of the measurement point 13 where the target device 3 is installed based on the three-dimensional coordinates of the optical center M', the known distance from the optical center of the prism 15 to the lower end of the pole 14, and the inclination angle and inclination direction of the pole 14 received from the target device 3.

[0105] In the third embodiment as well, the amount of deviation between the measurement position M and the optical center M' can be calculated as a measurement error Δe based on the measurement result of the prism 15 and the tilt angle and tilt direction of the pole 14. Therefore, even if the target device 3 is tilted and the measurement position M of the prism 15 is misaligned from the optical center M' of the prism 15, the three-dimensional coordinates of the optical center of the prism 15 can be obtained, and the measurement accuracy of the measurement point 13 can be improved.

[0106] Furthermore, since there is no need to set the target device 3 in a vertical position every time the target device 3 is placed at the measurement point 13, the measurement time can be shortened and the workability can be improved.

[0107] In the third embodiment, the tilt sensor 35 is provided in the target device 3, and the measurement error Δe is calculated based on the measurement result of the prism 15 and the detection result of the tilt sensor 35, i.e., the tilt angle and tilt direction of the pole 14. On the other hand, if the attitude of the pole 14, i.e., the tilt angle and tilt direction, can be detected or calculated by a device other than the tilt sensor 35, the measurement error Δe, which is the deviation between the measurement position M of the prism 15 of the present invention and the optical center M' of the prism 15, can be calculated, and the measurement result of the prism 15 can be corrected. [Explanation of symbols]

[0108] 1. Surveying System 2 Surveying equipment 3 Target Device 8 Ranging section 9 Tracking part 11 Ranging light 12 Tracking light 13 Measurement points 14. Paul 15 Prism 21 Calculation control unit 22 Memory section 26 balls 28 point cloud 32 OM Vector 33MP Vector 35 Tilt Sensor

Claims

1. A surveying system having a target device having a pole and a target whose distance from the bottom end of the pole is known, and a surveying instrument capable of measuring the target, wherein the bottom end of the pole is aligned with a predetermined measurement point, the surveying instrument calculates an O-M vector connecting the instrument center of the surveying instrument and the measurement position of the target, and an M-P vector connecting the measurement position and the measurement point, calculates an angle φ between the O-M vector and a plane that is perpendicular to the M-P vector and passes through the measurement position, calculates a measurement error between the measurement position and the optical center of the target based on the angle φ, corrects the measurement position based on the measurement error, and calculates the three-dimensional coordinates of the measurement point based on the corrected measurement position.

2. The surveying system of claim 1, wherein the target device is configured to swing the pole while aligning the lower end of the pole with a predetermined measurement point, the surveying instrument measures the target at at least three points, calculates three-dimensional coordinates of a virtual measurement point based on the measurement positions of each target, and calculates the M-P vector based on the measurement positions of the target and the virtual measurement point.

3. The surveying system according to claim 1, wherein the target device further comprises a tilt sensor, and the surveying device is configured to calculate the MP vector based on the measured position and the attitude of the pole detected by the tilt sensor.

4. The surveying system according to claim 2, wherein the surveying device is configured to calculate the degree of coincidence between the measurement point and the virtual measurement point as an accuracy, and when the accuracy meets a preset threshold value, correct the measurement position of each target, recalculate the virtual measurement point as the measurement point based on each corrected measurement position, and perform an operation to complete the measurement.

5. The surveying system according to claim 2, wherein the surveying device is configured to correct all measurement positions of the target each time the virtual measurement point is calculated, recalculate the virtual measurement point based on the corrected measurement position, calculate the degree of coincidence between the measurement point and the virtual measurement point as an accuracy, and when the accuracy satisfies a preset threshold value, regard the virtual measurement point as the measurement point and perform an operation to complete the measurement.

6. The surveying system according to claim 4 or claim 5, wherein the surveying device is configured to: define a distance from the bottom end of the pole to the target as a radius; calculate the center of a sphere that fits to each measurement position as the measurement point; calculate a reference sphere normalized with the radius of the sphere being 1; calculate the area of ​​the smallest curved surface that includes all the points on the surface of the reference sphere; and calculate the accuracy based on a comparison between the curved surface and a preset reference curved surface.

7. 7. The surveying system according to claim 6, wherein the surveying instrument further has a tracking function, and is configured to be able to measure the target while tracking it.

8. The surveying system of claim 7, wherein the surveying device is configured to sequentially calculate a sphere fitting to the measurement positions of at least three consecutively measured targets each time the target is measured, and to determine whether the target device is installed at the measurement point based on whether the distance between the centers of each sphere converges within a predetermined threshold range.

9. A surveying method comprising the steps of: calculating, with the bottom end of a pole aligned with a specified measurement point, an O-M vector connecting the instrument center of a surveying instrument and a measurement position of a target attached to the top end of the pole, and an M-P vector connecting the measurement position and the measurement point; calculating an angle φ between the O-M vector and a plane that is perpendicular to the M-P vector and passes through the measurement position; calculating a measurement error between the measurement position and the optical center of the target based on the angle φ; correcting the measurement position based on the measurement error; and calculating three-dimensional coordinates of the measurement point based on the corrected measurement position.

10. The surveying method according to claim 9, further comprising the steps of: swinging the pole while aligning the lower end of the pole with a predetermined measurement point, and measuring the target at at least three points; calculating three-dimensional coordinates of a virtual measurement point based on the measurement positions of each target; and calculating the M-P vector based on the measurement positions of the target and the virtual measurement point.

11. 10. The surveying method according to claim 9, further comprising the steps of: receiving an attitude of the pole from an inclination sensor provided on the pole; and calculating the MP vector based on the received attitude of the pole.

12. A surveying program that causes the surveying instrument to execute the following processes while aligning the bottom end of the pole with a specified measurement point: calculating an O-M vector connecting the instrument center of the surveying instrument and the measurement position of a target provided at the top end of the pole, and an M-P vector connecting the measurement position and the measurement point; calculating an angle φ between the O-M vector and a plane that is perpendicular to the M-P vector and passes through the measurement position; calculating a measurement error between the measurement position and the optical center of the target based on the angle φ; correcting the measurement position based on the measurement error; and calculating the three-dimensional coordinates of the measurement point based on the corrected measurement position.

Images