RU2383862C1 - Method for alignment of metering instrument and device for its realisation (versions) - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention is related to the field of geodesic instrument making, namely to instruments, which are used to measure distances along sighting line for alignment of reflectors, sighting marks and targets. Method for alignment of metering instrument includes preliminary alignment of instrument in point of area, where linear and angular elements of alignment error are measured versus selected initial side of measured angle or line of area. On completion of measurements, values are reduced with account of data on elements of alignment error, and then, taking errors into account, vertical axis of instrument rotation is finally set into upright position. Method is realised with device that represents optical aligner equipped with micrometre, optical element of which is a grid with count index. Aligner comprises electronic system of data registration and processing, which includes code sensor, units of heights input, units for calculation of distances, scale image factor, directional angles, corrections of measured directions and unit of linear error element correction.

EFFECT: reduced time inputs for proper installation of instrument into working position and improved accuracy of measurements.

3 cl, 10 dwg

Description

The invention relates to the field of geodetic instrument engineering and can be used when installing a geodetic instrument in a working position, namely when centering the instrument in order to eliminate centering errors in the values measured by the instrument. The predominant use of the invention is in electronic geodetic instruments, for example electronic total stations, light-range finders, in laser instruments that specify horizontal directions, etc., for centering reflectors, target marks and targets. In addition, the invention can be used for centering optical devices, mainly theodolites.

A known method of measuring horizontal angles with automatic centering of the theodolite and signals, including centering the theodolite and supports at the observed points, sequential rearrangement of the theodolite and signals in the supports (see Borshch-Komponets V.I., Navitny AM, Knysh G.M. Mine surveying. A textbook for technical schools. - M .: Nedra, 1985, p.119-120).

The disadvantage of this method is the relatively high complexity of the measurement, as well as the use of several tripods for measurements in order to reinstall theodolite and signals on them.

There is also a method of centering a geodetic instrument using an optical plummet, taken as a prototype, in which the tripod is mounted so that one of its legs is at some distance from the point at which the centering is performed, and the tripod is moved for the other two legs, achieving a vertical position axis of the optical plummet near the centering point and observing the horizontal position of the tripod head. After the pre-installation of the tripod is completed, its legs are strengthened, continuing to center the device when they are pressed into the ground. Then, loosening the set screw, the measuring device is moved to the tripod head until the center of the optical center line grid is aligned with the center point (see, for example, Fedorov V.I., Titov A.I., Holdobaev V.A. Workshop on engineering geodesy and aero geodesy : Textbook for universities. - M .: Nedra, 1987, p.56, §21).

The disadvantages of this method are the following: a relatively large amount of time for forced centering by the method of successive approximations, since each time the vertical axis of rotation of the measuring device is brought into a vertical position, the instrument is not aligned horizontally. In turn, leveling the device leads to a violation of the centering, etc. In addition, the effect of the residual centering error remains unknown.

Known devices for centering geodetic instruments and equipment containing seats for the unambiguous installation of measuring instruments, which ensures centering with high accuracy (see Geodetic methods for studying the deformation of structures / A.K. Zaitsev, S.V. Marfenko, D.Sh. Mikhelev et al. - M .: Nedra, 1991, p.29-32).

The disadvantage of these devices is the need for their stationary fixing on special stable bases, which excludes the possibility of their use in the production of mass measurements.

Known devices for the automatic centering of theodolite and signals (sighting targets), consisting of a telescope rotationally connected to the buck, which is inserted into the stand sleeve of the angle measuring device or signal, two crosswise cylindrical levels attached to the buck. When using the specified device, leveling and centering of the stand mounted on a tripod is carried out, in which the measuring device or signal is then installed (see Gusev N.A. Surveying and geodetic instruments and devices. - M .: Nedra, 1968, p. 304–306 )

The disadvantage of these devices is a long centering process, including reinstallation of the equipment, as well as the effect on the measurement accuracy of the residual unknown centering error.

Known optical plummet (prototype), consisting of a telescope, the axis of which is aligned with the vertical axis of rotation of the device, a grid, a prism that changes the direction of the axis of the telescope, while the plane formed by the axis of the telescope coincides with the collimation plane of the device or forms a well-known angle (see, for example, Zakharov A.I. Geodetic instruments: Reference. - M .: Nedra, 1989, p. 46, fig. 26, fig. 27).

A disadvantage of the known optical plummet is that it does not allow to measure and thereby take into account the magnitude of the centering errors, as a result of which it is necessary to perform a careful installation of the measuring device over a fixed point in the terrain, which leads to a significant investment of time. In addition, even after careful centering, the residual centering error, especially for accurate and high-precision measurements at short distances in cramped conditions, affects the accuracy of measuring directions (readings along the horizontal circle of the instrument), horizontal angles and distances and is unknown to the observer.

To eliminate these drawbacks, a method is proposed for centering the measuring device by the analytical method of reducing the values measured by the device taking into account the linear and angular elements of the centering error, which are determined respectively by the mismatch of the projection of the vertical axis of rotation of the device with a fixed terrain point and the angle between the position of the linear element and the collimation plane of the device combined with one of the sides of the measured horizontal angle, taken as the original.

The essence of the method, the use of which eliminates the influence of the centering error of the device on the accuracy of the measured values, as well as the design of devices designed to implement the method, are explained in the diagrams shown in figures 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10.

Designations used in figure 1:

- x _B Au _B and x _C Au _C - conventional rectangular coordinate systems, the x axis of which is oriented by the projection of the side of the measured angle onto the horizontal plane or the direction determined by the reading along the horizontal circle of the measuring device;

- A _O , B _O and C _O are points fixed on the terrain at which the centering of the geodetic instrument or sighting target is performed;

- A, B and C - points that are actual projections of the vertical axis of rotation of the device (point A) and sighting targets (points B and C);

- a, b, and c are linear elements of the centering error, respectively, at points A _O , B _O, and C _O ;

- γ _aB and γ _b are the corner elements of the centering error at the points A _O and B _O in the coordinate system x _B Au _B for the determined direction A _O B _O (N _OAB );

- γ _ac and γ _c are the angular elements of the centering error at the points A _O and C _O in the coordinate system x _C Au _C for the determined direction A _O C _O (N _OAC );

- N and N _O with indices of the side of the measured horizontal angle (direction) - respectively measured and determined direction;

- β and β _O are the respectively measured and determined horizontal angles, calculated as the differences of the corresponding directions;

- L and L _O with direction indices - respectively measured and determined distances;

- Δβ _AB and Δβ _AC are the angular corrections in the measured directions, respectively, in N _AB and N _AC ;

- α _оАB and α _оАC - conditional directional angles of the corresponding sides of the measured horizontal angle (direction) in the adopted conventional systems of rectangular coordinates.

Designations in figure 2:

1 - telescope lens;

2 - eyepiece of the telescope;

3 - a grid of a telescope;

4 - a prism that changes the direction of the axis of the telescope;

5 - drum micrometer linear displacements;

6 - input unit height measuring device (target);

7 - encoder linear displacement;

8 - input unit directions of the corner elements of the centering;

9 is a unit for calculating the distances from the subject to the point of front focus of the telescope lens;

10 - block calculating the scale factor of the image;

11 - block correction of the linear element of the error of centering;

12 - unit for calculating the angular element of the error of centering;

13 is a unit for recording the measured directions of the angular element of the centering error (registration system related to the measuring device);

14 - analog block calculating the coordinates of the defined points;

15 - unit for recording measured distances (registration system related to the measuring device);

16 - block calculating the directional angles of the determined directions;

17 - unit for calculating corrections in the measured directions;

18 - unit for calculating the determined distances;

19 is a block for calculating horizontal angles;

20 is a block calculating the determined directions;

21 - a unit for recording measured directions (a registration system related to a measuring device similar to block 13);

22 - storage device (registration system related to the measuring device);

A - projection of the actual position of the vertical axis of rotation

measuring device;

A _O is the point in the terrain at which the instrument is centered;

l is a linear element of the centering error (general notation).

Figure 3 presents a view of the field of view of the telescope optical plummet:

A and A _O are respectively the projection of the actual position of the vertical axis of rotation of the measuring device and the point of the terrain at which centering is performed;

- pos. a - after preliminary centering of the measuring device;

- pos. b - after combining the collimation plane of the centrir telescope with the direction of the linear element of the centering error;

- pos. in - after combining the center of the grid with point A _O ;

γ is the angular element of the centering error;

l is a linear element of the centering error.

Figure 4 presents the optical scheme of the telescope of the optical plummet with the path of the rays (without a prism). The diagram does not reflect the sign rule adopted in geometric optics, since the problem is solved only taking into account the geometry of the optical rays. Designations in figure 4:

1 - lens;

2 - an eyepiece;

A is a projection of the actual position of the vertical axis of rotation of the measuring device and the axis of the telescope of the optical plummet;

And _About - the point of terrain in which the centering of the measuring device or the target is made;

AA _O = l is a linear element of the error of centering;

l 'is the linear element of the error of centering the device in the image space (in the grid plane);

F and F 'are the points of the front and rear foci of the lens, respectively;

ƒ and ƒ 'are the front and rear focal lengths of the lens, respectively;

z is the distance from the subject to the center of the lens;

s and s' are the distances from the terrain point and from the image of this point, respectively, to the front and rear foci of the lens;

t is the change in distance s in the space of objects;

- indices 1 and 2 of the parameters - respectively, the initial position of the subject and its position after moving towards the lens.

In figure 5, the notation of the positions correspond to the notation shown in figure 2. Additional item:

23 is an optical element of a micrometer.

Figure 6 presents the grid 3 and the optical element 23 of the micrometer (see figure 5). The view of the grid field of view is shown at positions a, b and c:

- pos. a - after preliminary centering of the measuring device;

- pos. b - after combining the collimation plane of the centrir telescope with the direction of the linear element of the centering error;

- pos. c - after combining the index of the optical element of the micrometer with the point of the terrain in which the centering is performed.

In Fig. 7, the designations correspond to the designations shown in Fig. 2. Additional item:

24 - block correction of the distance from the subject to the front focus of the telescope lens.

In Fig. 8, the designations correspond to the designations shown in Fig. 2.

In Fig. 9, the designations correspond to the designations shown in Fig. 2. Additional item:

25 - optical element of the micrometer (plane-parallel plate).

Figure 10 presents the optical plummet and view of the field of view in the plane of the grid. Designations correspond to the designations shown in figure 2. Additional item:

26 - viewfinder (optical element, such as a rectangular prism).

Figure 1 shows the general case of measurements, corresponding to one of the possible algorithms for calculating corrections to the values measured by the device, determined by its purpose, when a measuring device, for example an electronic total station, is installed at point A _{O of the} area, and sighting targets at points B _O and C _O , in particular reflectors. Due to the centering error, the device and the target targets deviate from the true position of the indicated points and are located at points A, B and C., respectively.

In the adopted conditional coordinate systems xAy, the horizontal angles γ corresponding to the corner elements of the centering error are conditional directional angles of the linear elements of the centering error starting from points A, B and C to points A _O , B _O and C _O.

The algorithm for calculating the determined directions, horizontal angles and distances is based on solving direct and inverse geodesic problems (see, for example, Afanasyev V.G., Egorov A.P. Geodesy and surveying in transport construction. M .: Nedra, 1978, § 14, p.21-23).

In the conventional system of rectangular coordinates x _B Au _B from the solution of the direct geodesic problem, the coordinates of the points A _O and B _O 'are found.

In formulas (1) - (4), by the condition for choosing a system of rectangular coordinates x _A = 0, y _A = 0, x _B = L _AB , y _B = 0.

From the solution of the inverse geodesic problem, the conditional directional angle α _{oAB of the} determined side A _O B _{O of the} measured horizontal angle (direction) is found:

и полученного дирекционного угла α_oAB:The correction Δβ _{AB is} calculated as the difference of the conditional directional angles of the axis Ax _B of the coordinate system x _B Ay _B

and the obtained directional angle α _oAB :

Moreover, if α _{oAB is} more than 270 °, but less than 360 °, then 360 ° is subtracted from the obtained direction angle in formula (6). If α _{oAB is} greater than 0 °, but less than 90 °, then the correction value is equal to the obtained direction angle.

The determined direction N _{OAB is} obtained from the measured direction N _{AB by} introducing into it the correction calculated by formula (6):

The determined distance L _{AB is} found from the solution of the inverse geodesic problem by the formula

Similar calculations are performed for the determined side A _O C _{O of the} measured horizontal angle in a conventional rectangular coordinate system x _C Au _c .

In the conditional system of rectangular coordinates x _C Au _C, from the solution of the direct geodesic problem, the coordinates of the points A _O and C _{0 are found} :

In formulas (9) - (12), by the condition for choosing a system of rectangular coordinates, x _A = 0, y _A = 0, x _C = L _AC , y _C = 0.

From the solution of the inverse geodesic problem, the conditional directional angle α _{oAC of the} determined side A _O C _{O of the} measured horizontal angle (direction) is found:

и полученного дирекционного угла α_oAC:The correction Δβ _{AC is} calculated as the difference of the conditional directional angles of the axis Ax _C of the coordinate system x _C Ay _C

and the obtained directional angle α _oAC :

The conditions for calculating the correction are the same as indicated for formula (6). The determined direction N _{OAC is} obtained from the measured direction N _{AC by} introducing into it the obtained correction:

The determined distance L _{OAC is} found from the solution of the inverse geodesic problem by the formula

From the obtained values of the directions N _OAB and N _{OAC, the} value of the determined horizontal angle is calculated:

In the case when the observed points B and C on the terrain are strictly fixed and they do not center the sighting target (mark, reflector, etc.), then in coordinates calculation formulas (1) - (4) and (9) - ( 12), as well as in the formulas for calculating the distances (8) and (16), take b = 0, c = 0, i.e. x _Bo = L _AB ; y _Bo = 0; x _Co = L _AC ; y _Co = 0.

Using the centering method with the algorithm for analytical reduction of the measured values taking into account centering errors will significantly reduce the complexity of installing the measuring device, since the values of the linear centering elements are not eliminated by mechanical actions with the device, but their values and the corresponding angular position are determined directly in the measurement process relative to the selected side of the measured horizontal angle, taken as the original, and exclude The effect of centering errors is introduced by introducing appropriate corrections into all measured values determined by the purpose of the device. The accuracy of centering by the method of analytical reduction is determined not by the values of the elements of the error of centering, but only by the errors in the determination of these elements. For example, the value of the linear element of the centering error can be equal to 10-20 mm (or more) with the required accuracy of the mechanical centering equal to 0.2-0.5 mm.

As the analysis of formulas (5), (8), (13) and (16) shows, the angular element of the centering error is sufficient to measure with an accuracy of 0.5 ° -1 °, which is technically easy to implement. The requirements for the required accuracy of measuring a linear element of the centering error are practically determined by the requirements for the accuracy of the measured values and do not depend on the value of the linear element itself. Since Δβ is small, the effect of centering error in one direction (reference) can be estimated by the formula

where a is a linear element of the error of centering; γ is the angular element of the centering error; L is the length of the direction (side of the measured angle); ρ is the number of seconds in radian equal to 206265 ".

Taking into account the small influence on the Δβ value, the errors of measurement of the angular centering element, as well as the errors of distance measurement, can be written for the error of correction in the direction that

where m _a is the measurement error of the linear element of the centering error.

Since the measured horizontal angle is formed by two sides, in the general case it can be accepted that the error in the measured angle due to the measurement error of the linear element will double and amount to 2m _Δβ .

On the other hand, following the principle of “insignificant error”, the fraction of 2m _Δβ in the error in measuring the horizontal angle should be

where m _β is the specified accuracy of horizontal angle measurement; λ is a coefficient characterizing the allowable share of one of the errors that make up the total measurement error of any quantity. Most often take λ = 3.

In view of (19) and (20), we can write for m _a

Suppose that a horizontal angle close to 180 ° is measured (the worst conditions), the sides of the angle are 50 m each, λ = 3, γ = 90 °, the specified accuracy of measuring the horizontal angle is 5 ". For the indicated measurement conditions, m _a = 0, 2 mm.

Providing in this case centering with an accuracy of 0.2 mm is practically difficult to implement, however, measuring a linear element with an accuracy of 0.2 mm is technically feasible, even with greater accuracy than that obtained in the example.

To implement the inventive method, an optical plummet is proposed (Fig. 2), equipped with a micrometer for measuring linear displacements, the optical element of which is mounted with the possibility of translational movement in the direction transverse to the axis of the telescope, an electronic system formed by the height input unit of the measuring device (sighting target), linear encoder encoder, input units for the directions of the corner elements of centering, calculating the distance from the subject to the front focus of the lens computation of the image scale, correction of the linear element of the error of centering, calculation of the angular element of the error of centering, the analog unit for calculating the coordinates of the defined points, the blocks for calculating the directional angles of the determined directions, corrections to the measured directions, the determined distances, horizontal angles, the determined directions and the storage device, when the drum of the micrometer is connected with a code encoder of displacement, which is installed with the possibility of transmitting a signal to the unit correction of the magnitude of the linear element of the error of centering, the said correction unit is installed with the possibility of receiving a signal from the unit for calculating the scale factor of the image, which is installed with the possibility of receiving a signal from the unit for calculating the distance from the object to the front focus of the telescope lens, the said unit is installed with the possibility of receiving a signal from enter the height of the measuring device, blocks for correction and calculation of the corner elements of the centering error are installed with the possibility of information transfer to the analog block, which calculates the coordinates of the defined points, the said block for calculating the angular elements of the centering error is installed with the ability to receive information from the input units of the directions of the angular elements of the centering error and the directions of the corner elements of the centering error, and the aforementioned analog block is installed with the possibility of receiving a signal from the block recording measured distances and transmitting information to blocks for calculating directional angles, determined for example phenomena and determined distances, the directional angle calculation unit is installed with the possibility of interaction with the unit for calculating corrections in the measured directions, which is installed with the possibility of transmitting a signal to the unit for calculating the determined directions, said unit is installed with the possibility of transmitting a signal to the unit for calculating horizontal angles and receiving a signal from the unit registration of measured directions, the storage unit of the measuring device is installed with the possibility of receiving signals from blocks of calculation tions determines the direction of horizontal angles and determines the distance.

Figure 2 shows the optical center of the measuring device, consisting of a telescope including a lens 1, an eyepiece, 2, a grid 3, a micrometer for measuring linear displacements with a drum 5, mechanically connected to the grid, which is a movable optical element of the micrometer, prism 4, changing the direction of the axis of the telescope. The drum 5 of the micrometer is connected to a code sensor 7, which registers the linear displacements of the grid 3, the signal from which is sent to the block 11 for correcting the value of the linear element of the centering error. Block 11 also receives the value of the scale factor of the image determined by the computing unit 10 by the value of the height of the device specified by block 6 and the differences of the heights of the device specified in block 9. In block 8, the measured directions of the linear elements of the centering error are generated (or they are selected from the system 13 measuring device that records samples in a horizontal circle). In block 12, the information which comes from blocks 8 and 13, the calculation of the angular elements of the centering error is performed. Information from the sides 11 and 12, as well as the values of the measured distances of the registration system 15 of the measuring device, enter the analog block 14 for calculating the conditional rectangular coordinates. Information from block 14 goes to blocks 18 and 16. Based on the values of the received coordinates, block 18 calculates the determined distances, and block 16 calculates the conditional directional angles and transfers their value to block 17. In block 17, corrections to the measured directions and values are calculated which enter block 20. The values of the measured directions from the registration system 21 of the measuring device are entered in the same block. In block 20, operations are performed to calculate the determined directions, the determined horizontal angles as the differences of the determined directions. The resulting distances (block 18), horizontal angles (block 19) and directions (block 20) are received in block 22 of the storage device of the measuring device.

The implementation of the centering method using the claimed device is as follows.

After pre-installation of the measuring device and sighting targets (pre-centering), measure the height z of the measuring instrument and sighting targets, defined as the distance from the point of terrain in which the centering is performed to the lower mechanical part of the vertical axis of rotation of the device from the lens side of the optical center (figure 2 ) The obtained values are entered into block 6. Then the collimation plane of the telescope of the measuring device is combined with the measured direction (Fig. 3, pos. A) and the count is recorded along the horizontal circle of the device. The image of the projection of the vertical axis of the plummet (the vertical axis of rotation of the measuring device or the target) is located in the center of the grid (point A), the image of a fixed point A _{On the} ground due to the centering error l does not coincide with point A and falls into an arbitrary place of the grid. Next, the collimation plane of the telescope telescope is combined with the direction of the linear element of the centering error and register the count along the horizontal circle of the device (Fig.3, pos. B). By rotating the drum 5 micrometer, the center of the grid 3 is aligned with point A _O (Fig. 3, item c). The linear element of the centering error measured by the micrometer in the image space is recorded in block 7. Corresponding information is also received from the targeting units in the same block. In block 8, the values of the angular elements of the centering error are entered both from the registration system of the measured directions of the measuring device (block 13), as well as similar information from the sighting targets. Further processing of the obtained data is carried out by the electronic system shown in figure 2, the purpose of the elements of which is indicated above, in accordance with the established algorithm for solving the problem, determined by the sequence of solutions according to formulas (1) - (17).

Consider the principle of determining the scale factor of the image K (correction factor) of the linear element of the centering error, illustrated in figure 4.

The optical scheme of the telescope of the optical plummet is presented in figure 4 without a prism.

The same value of the linear centering error will be displayed in the grid plane by different values if the height of the device z changes by an amount t in the space of the object, for example, when the measuring device is installed at other points during transitions from station to station.

и, кроме того, изменится линейный размер изображения линейного элемента на величину

, т.е. изменится масштаб изображения. Элементы построения изображения после изменения высоты прибора показаны на схеме с индексом 2.In accordance with the scheme, after preliminary centering at point A _O, lens 1 constructs an image of the region at point A _O (in Fig. 4, the image is constructed according to the rules of geometric optics). The specified ratio of the parameters of the image is determined on the diagram with index 1 for the corresponding values. When changing the height z of the measuring device, the image of the linear element will shift along the axis of the telescope by

and, in addition, the linear image size of the linear element will change by

, i.e. zooms out. Elements of image construction after changing the height of the device are shown in the diagram with index 2.

Based on the geometric path of the rays, we can write that

The minus sign at the value of t corresponds to the scheme shown in figure 4. In the general case, the plus sign should be written in the corresponding formulas, and calculations should be made taking into account the actual sign of t.

:The total longitudinal displacement S of the image in the plane of the grid 2 is defined as displacement by

:

The change in the transverse magnitude of the image of a linear element (zooming) can be represented in relative form in the form of a coefficient K:

The magnification of the image of the subject in the plane of the grid of threads is determined by the ratio

The total magnification of the telescope of the optical plummet is selected so that it is equal to 2 ^x -3 ^x . This is regulated by the selection of the focal length of the eyepiece 2, and also taking into account a certain average height z of the instrument for the measurement conditions. Thus, for the optical plummet you can set some constant value for increasing the telescope for a given height of the device

In this case, the scale factor of the image in the plane of the telescope grid will be constant and equal to

When changing the height of the device by

scale factor changes. Given the formula (30)

The micrometer scale of the optical plummet is designed taking into account the value of K _O , as well as taking into account the total increase in the telescope of the plummet.

If in this case we measure in the grid plane the value l _{ism of} any segment, then its actual value l _о will be determined taking into account the current value of the scale factor:

Suppose that the optical plummet is calculated for ƒ = 150 mm, s _о = 1000 mm (z _o = 1145 mm); K _O = 0.1500. Suppose further that the linear error of centering when installing the device at the station after preliminary centering was l = 10 mm. For these conditions, the image size of the linear element of the centering error in the plane of the grid 3 of the telescope telescope will be

Suppose that when measuring the height of the device, a value of z = 1270 mm was obtained. Thus, the height difference Δs = (z _i -z _o ) = (1270-1145) = 125 mm.

For these conditions, the value of the scale factor is equal to

The image size of the linear element of the centering error in the grid plane is equal to

Relation (33) allows us to determine the true value of a linear element:

Suppose that the height of the device was measured with an error of 5 mm and the measurement result was 1265 mm. In this case, the calculation

При вычислении линейного элемента в данном случае получим

.scale factor will give the result

When calculating the linear element in this case we get

.

The calculation results, which are close to practically possible to obtain them, show that the error in measuring the height of the device weakly affects the error in measuring the value of the linear element of the centering error. Moreover, it is practically feasible to measure the height of the device and with a smaller error than in the example, for example, 1-3 mm. That is, practically this error can be reduced to negligible to determine the true value of the linear element of the centering error.

In view of the foregoing, in the passport data of the optical plummet (measuring device) the following data should be indicated, which are permanent for the device and stored in its electronic system:

- the focal length of the telescope telescope lens;

- a fixed distance from the subject to the front focus point of the lens of the telescope telescope;

- the magnification factor of the image for fixed values of the focal length of the lens and the distance from the subject to the focal point of the lens of the telescope telescope;

- the required accuracy of measuring the height of the device (in the instructions for use of the device).

When using an electronic total station, the process of introducing corrections to the measured value of a linear element can be easily automated by supplementing the flowchart for processing the measurement results with the corresponding blocks for calculating the coefficient K according to the algorithm of formula (32) and the block for calculating the true value of a linear element according to formula (33). Corresponding electronic units for receiving and processing information, interfaced with similar units of the measuring device and the optical center of the measuring device, may also contain sighting targets. In this case, the final processing of information (reduction of the measured directions, horizontal angles and distances) can be performed after field work or in the course of their implementation when connecting the measured data storage devices of the target targets to the information processing system of the measuring device.

The electronic system for recording and processing information can be structurally and functionally combined with the corresponding electronic system of the measuring device. Many computational operations, for example, the calculation of horizontal angles, directional angles, coordinates of points, etc., are performed directly by the measuring device.

When determining the angular element of the error in centering the target, it should be borne in mind that the value of the measured angle element must be changed to 180 °, since the sight on the measuring device from the target is carried out in the direction opposite to the positive direction of the x axis.

Figure 2 presents a diagram of the device, the optical element of the micrometer which is a grid 3 of the telescope, mechanically connected with the drum of the micrometer. A similar problem, i.e. the determination of the values of the elements of the centering error can be solved with the same degree of accuracy when using other optical elements. Let's consider some of them.

Figure 5 presents a diagram of a device in which the optical element of the micrometer is a glass plate 23, similar to the grid 3 of the telescope. As the specified additional element 23, and the grid 3 have fixed indices, the planes of which are facing each other. Element 23 is connected to the drum of the micrometer. The action of the device, including the process of processing and accumulating information, is similar to the action of the device shown in figure 2. It is convenient that in the field of view the index of the grid 3 remains stationary, and the index of the element 23 will occupy different positions relative to the specified fixed index. Fig. 6 (pos. A) shows the field of view of the optical plummet after bringing the device into working position with preliminary centering at point A _O. After pointing the collimation plane of the centering telescope in the direction of the fixed point A _O (pos. B) by the action of a 5 micrometer drum, the reference index of the optical element of the micrometer is combined with the point A _O (pos. C), as a result of which the preliminary value of the linear element of the centering error is determined.

Similarly, the problem of reducing the elements of the centering error is also solved when using a prism 4 as a movable optical element of the micrometer, which changes the direction of the optical axis of the center telescope (see Fig. 8). Prism 4 is installed with the possibility of translational movement along the axis of the telescope of the optical plummet or rotational motion in the collimation plane of the optical plummet. With the indicated displacements of prism 4, the image of the terrain point at which the instrument is centered, after preliminary centering and alignment of the collimation plane of the center telescope with the direction of the linear element of the centering error, is introduced into the center of the grid 3. Further processing of the measurement results is carried out according to the algorithm established above, presented in the description the claimed device (see figure 2).

Figure 9 presents a diagram of the claimed optical plummet, in which the optical element of the micrometer is element 25, made, for example, in the form of a plane-parallel plate mounted with the possibility of rotational movement in the collimation plane of the telescope, or, as an alternative to plane-parallel plate, in the form of optical wedges mounted translationally along the axis of the telescope.

The action of known optical micrometers containing plane-parallel plates or optical wedges is based on the parallel movement of optical beams during rotation of a plane-parallel plate or during translational displacement of optical wedges. These devices are known and widely used in reading systems of accurate and high-precision geodetic instruments.

When the plane-parallel plate is tilted relative to the initial path of the optical rays by any angle due to the refraction of the rays, the optical beams (images) shift on the working faces of the plate, depending on the angle of inclination of the plate, the refractive index of the glass, and its transverse dimensions. Optical wedges form a plane-parallel plate when combined. When the optical wedges are removed from each other as a result of the refraction of the optical rays determined by the wedge parameters, the image is also parallel to the original image shift (see, for example, Gusev N.A. Surveying and geodetic instruments and devices. - M.: Nedra, 1968, p. .114-125, §42, §43).

When moving the optical element 25, the image of the terrain point at which the centering is performed is combined with the reference horizontal index of the grid 3, as when using the optical elements 23 (Fig. 5) and 4 (Fig. 8).

The optical element 25 (plane-parallel plate or optical wedges) can be placed both in front of the lens 1 and between other optical elements of the telescope optical telescope, including between the grid 3 and the eyepiece 2. The placement of the moving optical micrometer element between the grid and the eyepiece is preferred , since in this case it is possible to reduce the size of this element, since with this arrangement of the optical element with a micrometer, a reduced value of the linear element that centering errors. For example, the location of the optical element of the micrometer in front of the lens is practically difficult, since the size of such an element must be very large for the relatively large linear elements of the centering error allowed in the claimed method, for example 10-20 mm

When using a plane-parallel plate or optical wedges as optical elements of a micrometer, preliminary alignment of the measuring device is performed taking into account the possible measurement range of the optical micrometer.

As a second variant of the claimed device, an optical plummet is proposed (Fig. 7), in which the movable optical element of the micrometer is combined with the lens 1 and prism 4, mounted with the possibility of simultaneous translational movement along the vertical position of the optical plummet. When moving the indicated elements of the micrometer, after preliminary centering the device and combining the collimation plane of the centering telescope with the direction of the linear element of the centering error, the image of the linear element in the collimation plane moves. A 5 micrometer drum acts until the fixed point A _O is aligned with the center of the grid 3.

The composition of the electronic circuit of the second embodiment of the claimed device is identical to the electronic circuit of the first embodiment of the claimed device, with the exception of the unit for correcting the distance from the subject to the front focus of the lens (block 24, Fig. 7), which is additionally introduced to account for changes in the distance from the subject to the front focus of the lens.

The purpose of this block is explained as follows.

When moving the optical element of the micrometer (prism 4 and lens 1) to measure the value of the linear element of the centering error, the height of the device changes by a value d equal to the amount of movement of the optical element of the micrometer. In order to take into account changes in the height of the device, the electronic information processing system of the optical plummet is provided with a parameter s correction unit 24, which receives the values of the corresponding distances from the object to the front focus of the lens from block 9, as well as the values of the measured linear element of the centering error corresponding to the actual displacement d of the optical element micrometer recorded in block 7. The value of the distance s after its correction will be equal to

The value of d in the formula (34) and further in the formula (35) should always be taken with a minus sign for the given optical plummet scheme. In other schemes, it is possible that the value of d should be taken with a plus sign.

Information from block 24 is transmitted to block 10 calculating the scale factor of the image, the calculation algorithm of which is determined by the ratio

and then from block 10, the value of the scale factor is sent to block 11 for calculating the true value of the linear element of the centering error. Further information processing is similar to that considered for the first embodiment of the claimed device.

As mentioned above, a device for measuring the linear and angular elements of the centering error, it is advisable to install and on the target. In this regard, each sighting target is equipped with one of the variants of the claimed devices with an autonomous electronic circuit for accumulating measurement information. Information storages are used to register the obtained values of the elements of the error in centering the target targets in the electronic system of the measuring device. Obviously, there is no need to use the considered devices for sighting purposes if sighting targets are installed at the facility permanently or are installed with forced centering.

Information from sighting targets can be obtained both visually and then manually entered into the electronic system of the measuring device. So, for example, the telescope grid 3, which is the optical element of the micrometer (see Fig. 10), can have a linear scale for recording the magnitude of the linear element of the centering error, and the magnitude of the angular element of the centering error can be obtained by turning the grid around its axis with the micrometer drum until it is aligned points A _O with the axis of the scale. In the initial state, the linear scale of the grid occupies a position at which its axis coincides with the collimation plane of the centir, i.e. coincides with the vertical plane. The rotation of the grid is recorded using the 5 micrometer drum (visually or automatically), the reading on the scale is also recorded visually on the linear scale of the grid 3 or automatically. Automatic registration of the linear reference can be achieved, for example, using a movable grid 23 (Fig. 5) with a reference index associated with the drum 5 of the micrometer. In this case, the device will need to use two micrometers: one for recording angular, and the second for recording linear displacements.

When using the circuits of the claimed devices for sighting purposes, in order to install the collimation plane of the plummet on the vertical axis of rotation of the measuring device, it is advisable to install a viewfinder 26 in front of the plummet lens, made, for example, in the form of a prism that can be inserted into the field of view of the telescope centering and turning in its collimation plane. An optical plummet with a viewfinder is intended for use in optical plummet targets, when it is necessary to aim at the vertical axis of the measuring device in the opposite direction of the conventional rectangular coordinate system selected at the x axis.

The above data processing scheme for the first and second device variants is built taking into account the calculation algorithm given in the description of the method. The calculation algorithm may be somewhat different. For example, the horizontal angle can be obtained not as the difference in directions according to formula (17), but as the difference in the directional angles of the corresponding directions, if the station adopts a common conditional system of rectangular coordinates, one of the axes of which coincides with one of the sides of the measured angle. In this case, to calculate the coordinates, for example, point C _O , in the coordinate system x _B Au _B (Fig. 1), it is first necessary to determine the coordinates of point C in this coordinate system, calculate the directional direction angle of the linear element c in the same coordinate system, then the coordinates of point C to calculate the desired coordinates of the point C _O.

If the collimation planes of the measuring device and the telescope of the optical plummet do not coincide, but form some angle known for the given design of the measuring device, then a correction for the value of this angle is introduced into the value of the angular element of the centering error. If necessary, these actions are also carried out on sighting targets equipped with the optical centering designs discussed above with electronic or visual recording of the values of the linear and angular elements of the centering error.

The proposed device is intended primarily for use in electronic total stations, however, it can be used in electronic theodolites, light range finders, optical theodolites and range finders with electronic or visual recording of measurement results, as well as in other devices, including optical-mechanical, the installation of which in the working position requires centering at a fixed point in the terrain.

The implementation of the method of centering the measuring device by the method of reducing the measured values, taking into account the values and position relative to the collimation plane of the measuring device, the elements of centering errors will reduce the time for high-quality installation of the device in the working position and significantly improve the accuracy of measurements. In this case, the preliminary centering should only ensure that the image of the point at which the device is centered falls within the field of view of the centering telescope grid.

Claims (3)

1. A method of centering a measuring device, mainly a geodesic, for example an electronic total station, comprising preliminary and then final installation of the vertical axis of rotation of the device in a vertical position and combining the projection of the vertical axis of rotation of the device with a fixed terrain point, characterized in that after the centering of the measuring device is measured distance from the point of terrain at which the centering is performed to the fixed mechanical part of the measuring device a) measure the values of the linear and angular elements of the centering error, determined respectively by the mismatch of the projection of the vertical axis of rotation of the device with a fixed terrain point and the angle between the direction of the linear element and the collimation plane of the device, combined with one of the sides of the measured angle, taken as the initial one, and correct the linear element taking into account changes in the height of the measuring device relative to its nameplate value and analytically reduce the measured values taking into account the values of the elements of the centering error. 2. A device for centering a measuring device, comprising an optical plummet including a telescope with a lens, an eyepiece, a reticle, a prism that changes the direction of the axis of the telescope, the axis of which is aligned with the vertical axis of rotation of the device, characterized in that the telescope is equipped with a micrometer, comprising an optical element coupled to the drum of the micrometer and mounted to move relative to the axis of the telescope by the drum of the micrometer, wherein said device It includes an electronic system for recording and processing data, partially combined with an electronic system for recording and processing data of the measuring device, and containing a unit for entering the height of the measuring device, a code sensor that records the movements of the optical element of the micrometer, a unit for inputting the directions of the angular elements of the centering error, a distance calculation unit from the subject to the front focus point of the telescope lens, block for calculating the scale factor of the image, block magnitude correction s linear element of the error of centering, block for calculating the angular element of the error of centering, block for recording the measured directions of the corner element of the error in centering, analog block for calculating the coordinates of the points being determined, block for recording the measured distances, block for calculating the directional angles of the determined directions, block for calculating the corrections of the measured directions, block for calculating the determined distances, horizontal angle calculation unit, determined direction calculation unit, reg block strata of the measured directions and a storage device, wherein said micrometer drum is connected to a code displacement sensor, which is installed with the possibility of transmitting a signal to the block for correcting the value of the linear element of the centering error, said correction block is installed with the possibility of receiving a signal from the block for calculating the scale factor of the image, which is installed with the possibility of receiving a signal from the unit for calculating the distances from the subject to the point of front focus of the telescope lens, mentioning The plugged-in unit is installed with the possibility of receiving a signal from the height input unit of the measuring device, the correction and calculation units of the centering elements of the centering error are installed with the possibility of transmitting information to an analog unit that calculates the coordinates of the points to be determined, and the unit for calculating the corner elements of the centering error is installed with the ability to receive information from blocks input directions of the corner elements of the centering and directions of the corner elements of the error of centering, and yn the curled analog block is installed with the possibility of receiving a signal from the block for recording the measured distances and transmitting information to the blocks for calculating the directional angles of the determined directions and the determined distances, the block for calculating the directional angles is installed with the ability to interact with the block for calculating the corrections in the measured directions, which is installed with the possibility of transmitting the signal to a unit for calculating determined directions, said unit is installed with the possibility of transmitting a signal to a unit for calculating horizontal total angles and signal reception from the measured direction recording unit, the measuring device memory unit is installed with the ability to receive determined directions, horizontal angles and determined distances from the calculation units, while the moving optical element of the micrometer connected to the drum of the micrometer is a grid with an index and scale or a plane-parallel plate mounted in the optical path of the rays with the possibility of rotational motion in the collimation plane of the telescope, or pticheskie wedges mounted for translational movement along the axis of the telescope, or prism installed with the possibility of translational or rotational movement in the plane of the collimating telescope. 3. A device for centering a measuring device, comprising an optical plummet including a telescope with a lens, an eyepiece, a reticle, a prism that changes the direction of the axis of the telescope, the axis of which is aligned with the vertical axis of rotation of the device, characterized in that the telescope is equipped with a micrometer, containing an optical element associated with the drum of the micrometer, including a telescope lens and a prism mounted with the possibility of simultaneous movement relative to the axis of the telescope, about an adjustable micrometer drum, said device including an electronic data recording and processing system, partially combined with an electronic data recording and processing system of the measuring device, and comprising a height input unit for the measuring device, a code sensor recording the movements of the micrometer optical element, and a direction input unit the angular elements of the centering error, the unit for calculating the distances from the subject to the front focus point of the telescope lens, the subtracting unit the scale factor of the image, block for correcting the value of the linear element of the error of centering, block for correcting the distance from the object to the front focus of the telescope lens, a unit for calculating the angular element of the centering error, a unit for recording the measured directions of the angular element of the centering error, an analog unit for calculating the coordinates of the defined points, registration unit measured distances, a unit for calculating the directional angles of the determined directions, a unit for calculating corrections and measured directions, a unit for calculating determined distances, a unit for calculating horizontal angles, a unit for calculating determined directions, a unit for recording measured directions and a storage device, wherein said micrometer drum is connected to a code encoder for displacement, which is installed with the possibility of transmitting a signal to the block for correcting the value of a linear error element centering and on the block correction of distances from the subject to the front focus of the lens, the said block correction of the magnitude of the linear ele The centering error component is installed with the possibility of receiving a signal from the scale factor for calculating the image coefficient, which is installed with the possibility of receiving a signal from the above-mentioned unit for correcting distances from the subject to the front focus point of the telescope lens, and the unit for calculating the distances from the object to the front focus of the lens is set to receive the signal from the height input unit and transmitting information to the said unit for correcting the distance from the subject to the front focus point of the lens will measure of the unit, the correction and calculation blocks of the angular elements of the centering error are installed with the possibility of transmitting information to an analog unit that calculates the coordinates of the points to be determined, the aforementioned unit for calculating the corner elements of the centering error is installed with the ability to receive information from the input units of the directions of the angular centering elements and the directions of the angular error centering, and the aforementioned analog block is installed with the possibility of receiving a signal from the register block radios of the measured distances and information transfer to the blocks for calculating the directional angles of the determined directions and the determined distances, the block for calculating the directional angles is installed with the possibility of interaction with the block for calculating the corrections in the measured directions, which is installed with the possibility of transmitting a signal to the block for calculating the determined directions, the said block is installed with the possibility transmitting a signal to a block for calculating horizontal angles and receiving a signal from a block for recording measured directions, block apominayuschego meter device is arranged to receive a defined direction calculating blocks of horizontal angles and distances determined.

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