A three-dimensional coordinate measurement method and device for an inertial navigation trolley based on a laser range finder

Abstract

The application discloses a kind of based on laser range finder's inertial navigation car three-dimensional coordinate measurement method and device, will be equipped with inertial navigation, odometer, computer and laser range finder's inertial navigation car to the vicinity of parallel to CPIII control point, target ruler is inserted into CPIII control point pre-embedded piece hole;Laser beam emitted by laser range finder is aligned with the axis of target ruler;Obtain the elevation of laser beam light spot on target ruler, CPIII control point number and the installation height of laser range finder;From the storage CPIII project file, extract the mileage, plane coordinate and elevation of CPIII control point, calculate the plane coordinate and elevation of track center line point, to obtain the geometric shape information and geometric state information of track line.The mode of the application can replace electronic total station, with small size, high measurement accuracy, strong adaptability, low cost, easy operation and other advantages.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of railway track measurement, and in particular to a simple measurement method for determining the planar coordinates and elevation of the track center point parallel to the CPIII control point mileage position of an inertial navigation trolley based on a laser range finder, a target ruler and a CPIII control point, so as to replace the total station instrument to provide the three-dimensional coordinate absolute measurement data of a limited number of key points for the "relative + absolute" track detection of the inertial navigation trolley. BACKGROUND

[0002] With the multiple speed-up of China's railway transportation and the rapid expansion of the high-speed railway network, the precision and operation efficiency of track geometry state detection work are highly required in railway construction and daily maintenance. The traditional track detection technology and equipment based on total station and CPIII engineering survey network gradually become a short board in railway construction and operation maintenance due to the defects such as high labor cost, slow measurement speed, easy to be affected by sunshine, climate and human factors, etc. Therefore, relevant scientific researchers at home and abroad have made great efforts to study the scientific research of inertial navigation equipment in track detection application, trying to make up for the shortcomings of existing track detection equipment by using the advantages of high relative accuracy, mobile measurement and being not affected by environment and human factors, so as to improve the precision and speed of track detection work, effectively reduce the labor cost, and greatly improve the work efficiency.

[0003] Inertial navigation is the abbreviation of inertial navigation technology, and its working principle is to measure the angular rate and acceleration of the carrier by gyroscopes and accelerometers, and to obtain the azimuth angle, attitude angle, velocity and position information of the carrier through integral operation. Inertial navigation belongs to a kind of mobile relative measurement equipment, which has the advantages of high precision, fast speed, strong autonomy, not affected by environment and human factors, etc., and can realize the rapid mobile measurement of track line. The inertial navigation measurement belongs to relative measurement, and its shortcomings are that it cannot provide accurate observation point position coordinates and elevation, and the measurement data contains uncertain drift error, which is called inertial navigation drift. The inertial navigation drift is inevitable due to the working principle of inertial navigation. The key component in inertial navigation is gyroscope, and the size of inertial navigation drift depends on the quality of gyroscope. Gyroscope is divided into mechanical gyroscope, laser gyroscope, optical fiber gyroscope, micro-mechanical electronic gyroscope and piezoelectric gyroscope. The mechanical gyroscope is no longer used due to its too complex production process and high cost. The laser gyroscope has the best measurement precision and stability, but its price is high, which is difficult to popularize; the optical fiber gyroscope has high precision and moderate price; the micro-mechanical electronic gyroscope has small size and low cost, but it is affected by environmental temperature change and vibration interference; the piezoelectric gyroscope is a solid-state gyroscope, which measures the rotation speed of the object by the piezoelectric effect of the crystal under external force. The piezoelectric gyroscope has the smallest size and the lowest price, but its measurement precision and stability are the worst. The inertial navigation used in track detection at present is mainly optical fiber inertial navigation.

[0004] Since the track detection requires measuring absolute coordinates and elevation, the point positioning equipment and the inertial navigation equipment are combined for use, on the one hand, the inertial navigation and the moving mode are used to measure the plane displacement and the height difference of most track lines, on the other hand, the point positioning equipment is used to determine the absolute plane position and the elevation of a few control points, so as to realize the absolute control of the inertial navigation measurement data. The commonly used point positioning equipment is mainly the traditional total station and the RTK receiver, wherein the measurement accuracy of the total station is the highest, reaching the millimeter level, but the price is very high. The price of the RTK receiver is low, but the measurement accuracy is only the centimeter level. At present, some equipment manufacturers have marketed the track detection equipment based on the total station and the inertial navigation, which is called the inertial navigation trolley.

[0005] The total station is the most commonly used measuring equipment in the track detection work, the CPIII control point is used for free station setting, and then the handcart with the installed prism is measured to determine the plane position coordinates and the elevation of the track center line. The moving measurement of the inertial navigation can realize the relative measurement of most line points, through the accurate measurement of the absolute coordinates of a few control points by using the total station, the relative measurement data of the inertial navigation is supplemented and corrected, so that the detection result meets the technical requirements. In order to effectively control the inertial navigation drift, the total station needs to be used to measure a control point every certain distance; this kind of measurement mode of the combination of the inertial navigation and the total station is called the "relative + absolute" type track detection.

[0006] In addition, the size of the inertial navigation drift is related to the length of the measurement time, the longer the measurement time is, the larger the drift error is, and vice versa. If the speed of the inertial navigation trolley is improved, the measurement time can be shortened, so as to improve the measurement accuracy. For example, if the measurement speed is doubled, the distance of the continuous measurement of the inertial navigation can also be doubled. In this way, the work efficiency is also doubled.

[0007] The total station adopts the polar coordinate measurement method, the relative position coordinates of the observation point are determined through the measurement of the azimuth angle, the inclination angle and the slant distance between the total station and the observation point. The total station belongs to a kind of precision electric control measuring instrument integrating the slant distance and the angle accurate measurement, the production price is very high, and multiple people need to cooperate to operate, which is time-consuming and labor-consuming.

[0008] The "relative + absolute" measurement of the inertial navigation trolley requires less control points, which greatly reduces the use rate and the cost performance of the total station. If a kind of simple structure and low price alternative measuring equipment is developed to meet the measurement demand of the inertial navigation trolley for the absolute coordinates and the elevation of a few control points, the production cost of the inertial navigation trolley can be further reduced, the operation process can be simplified, and the popularization and use of the future inertial navigation trolley can be promoted. SUMMARY

[0009] In order to solve the above-mentioned defects in the prior art, the purpose of the present application is to provide a simple method for measuring the position of an inertial navigation vehicle in a plane coordinate and an elevation parallel to a CPIII control point based on a laser range finder, a target ruler and the CPIII control point, which can replace an expensive total station to provide absolute measurement data of the control point for the inertial navigation vehicle in a relative and absolute measurement mode, thereby simplifying the overall structure of the inertial navigation vehicle, reducing the cost, reducing the number of personnel and improving the work efficiency.

[0010] The purpose of the present application is achieved by the following technical solutions.

[0011] In one aspect of the present application, a three-dimensional coordinate measurement method of an inertial navigation vehicle based on a laser range finder is provided, which comprises the following steps:

[0012] The inertial navigation vehicle equipped with an inertial navigation system, an odometer, a computer and a laser range finder is driven to the vicinity of a CPIII control point parallel to the CPIII control point and parked;

[0013] A target ruler is vertically or horizontally inserted into a pre-buried hole of the CPIII control point in the direction of the track;

[0014] The inertial navigation vehicle is moved, and the laser beam emitted by the laser range finder is aligned with the central axis of the target ruler, and then the vehicle is parked;

[0015] The elevation of the laser beam spot in the scale on the surface of the target ruler and the number of the CPIII control point are manually read, and the elevation of the laser beam spot in the scale on the surface of the target ruler, the number of the CPIII control point and the installation height of the laser range finder are input into the computer of the inertial navigation vehicle;

[0016] The computer of the inertial navigation vehicle extracts the mileage, plane coordinate and elevation of the CPIII control point from the CPIII engineering file according to the number of the CPIII control point, and calculates the plane coordinate and the elevation of the center line point of the track in combination with the elevation of the target ruler, the installation height of the laser range finder, the slant distance between the inertial navigation vehicle and the laser beam spot measured by the laser range finder, the azimuth angle, the inclination angle and the roll angle sent by the inertial navigation system.

[0017] Preferably, the installation direction of the laser range finder is perpendicular to the running direction of the inertial navigation vehicle and faces the CPIII control point side, and the installation height of the laser range finder is slightly higher than the height of the CPIII control point pre-buried part.

[0018] Preferably, the emission direction of the laser beam emitted by the laser range finder is perpendicular to the running direction of the inertial navigation vehicle and parallel to the tread surface of the running wheel of the inertial navigation vehicle, so that the horizontal angle of the laser beam is always the same as the horizontal angle of the track surface.

[0019] As preferred, the laser range finder measures the distance between the center of the inertial navigation trolley and the target ruler, and the three-dimensional coordinates of the track center point parallel to the CPIII control point position are decomposed into the measurements of the azimuth angle, the inclination angle, the roll angle, and the longitudinal, lateral and vertical distance components between the observation point and the CPIII control point.

[0020] The component measurement method is that the azimuth angle, the inclination angle and the roll angle are measured by using the inertial navigation device, the lateral and vertical distances are measured by using a laser range finder and a target ruler, and the longitudinal distance is adjusted to zero by moving the inertial navigation trolley.

[0021] As preferred, the inertial navigation is measured in the combined measurement mode of the inertial measurement unit (IMU) and GNSS, the azimuth angle, the inclination angle and the roll angle are calculated by using two groups of GNSS plane coordinates at a certain distance, and the lateral acceleration and the vertical acceleration are output by the inertial measurement unit (IMU).

[0022] In another aspect of the present application, a laser range finder-based inertial navigation trolley three-dimensional coordinate measurement device of the method is provided, which comprises an inertial navigation trolley arranged on a track, a laser range finder, a computer and an inertial navigation device arranged above the inertial navigation trolley, and a CPIII control pile arranged on one side of the track, wherein a hole for inserting a target ruler is reserved in the CPIII control pile, the target ruler is inserted into the hole and is parallel to the laser beam emitted by the laser range finder.

[0023] As preferred, the target ruler adopts a rectangular sheet structure with scales, and a cylindrical body with the same aperture as the embedded part hole of the CPIII control pile is arranged at the bottom of the target ruler, and the target ruler is inserted into the embedded part hole arranged horizontally outside the CPIII control pile.

[0024] As preferred, the target ruler adopts a rectangular sheet structure with scales, and a cylindrical body with the same aperture as the embedded part hole of the CPIII control pile is arranged at the bottom of the target ruler, and the target ruler is inserted into the embedded part hole arranged horizontally outside the CPIII control pile.

[0025] The present application has the following beneficial effects due to the above technical solutions:

[0026] The inertial navigation trolley based on the CPIII control point track center line plane coordinate and elevation measurement method described in the embodiments of the present application can produce the following calculation effects:

[0027] 1. The track center line plane coordinate and elevation measurement method of the present application uses a laser range finder and a target ruler to measure the maximum geometric variable between the track center line and the CPIII control point, including the slant distance and the height difference, so as to replace the use of a total station.

[0028] 2. The track center line plane coordinate and elevation measurement method fully utilizes inertial navigation or IMU or GNSS or designed line to determine the azimuth angle, inclination angle and roll angle of the track line, reads the CPIII control point mileage, plane coordinate and elevation data stored in the form of files, combines the trigonometric function algorithm, calculates the plane coordinate and elevation of the track center point, thereby simplifying the basic functions and structures of the laser measurement device, and achieving the purposes of reducing the volume, reducing the cost and simplifying the operation process.

[0029] 3. The track center line plane coordinate and elevation measurement device is a fixed component, and does not need to be adjusted during use, thereby facilitating the use of the staff.

[0030] 4. The track center line plane coordinate and elevation measurement device has multiple different track line azimuth angle, inclination angle and roll angle determination methods, and is suitable for different system structures and different scene applications.

[0031] 5. The track center line plane coordinate and elevation measurement method and device can be used in multiple cases such as railway straight lines, circular curves and transition curves, realizes accurate measurement of the track center line position coordinate and elevation of the CPIII control point, has a simple and fast measurement process, high measurement precision and strong adaptability. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings, which are included to provide a further understanding of the application and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principle of the application, and in the drawings:

[0033] Figure 1 is a specific embodiment of the method applied to the inertial navigation trolley elevation measurement;

[0034] Figure 2 is a specific embodiment of the method applied to the inertial navigation trolley plane coordinate measurement;

[0035] Figure 3 is a schematic diagram of the target ruler arranged on the CPIII embedded part on the ballast retaining wall top surface;

[0036] Figure 4 is a schematic diagram of the target ruler arranged on the CPIII pile side embedded part;

[0037] Figure 5 is an operation flow diagram of the method applied to the inertial navigation point position measurement;

[0038] Figure 6(a) abstractly shows the geometric relationship between the laser ranging device, the target, the CPIII control point, and the track center point in the horizontal plane when the track is a straight line (superelevation is zero). Point A is the position of the laser ranging device, point B is the position of the laser spot on the target, point C is the position of the CPIII control point, and point D is the position of the track center point. L is the horizontal distance between points A and B, H A , H B , H C , H D are the elevations of points A, B, C, and D, respectively.

[0039] Figure 6(b) abstractly shows the geometric relationship between the laser ranging device, the target, the CPIII control point, and the track center point in the horizontal plane when the track is a curve (superelevation is not zero). Point A is the position of the laser ranging device, point B is the position of the laser spot on the target, point C is the position of the CPIII control point, and point D is the position of the track center point. L is the horizontal distance between points A and B, and γ is the angle of inclination of the laser beam.

[0040] Figure 7(a) shows the geometric relationship between the laser ranging device and the track center point in the vertical plane when the longitudinal slope is not taken into account.

[0041] Figure 7(b) shows the geometric relationship between the laser ranging device and the track center point in the vertical plane when the longitudinal slope is taken into account.

[0042] Figure 8(a) shows the geometric relationship between the laser ranging device, the projected length S, the track azimuth angle Ψ, and the track center point in the horizontal plane when the longitudinal slope is not taken into account.

[0043] Figure 8(b) shows the geometric relationship between the laser ranging device, the projected point A' of point A in the track top surface, the projected length S, the track azimuth angle Ψ, and the track center point in the horizontal plane when the longitudinal slope is taken into account.

[0044] In the figures: 1 is the inertial navigation trolley, 2 is the inertial navigation device, 3 is the running wheel, 4 is the computer, 5 is the laser ranging device, 6 is the target, 7 is the CPIII embedded part, 8 is the CPIII control pile, and 9 is the track. DETAILED DESCRIPTION

[0045] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions thereof are used to explain the present application and are not intended to limit the present application.

[0046] The three-dimensional coordinate measuring device for the inertial navigation trolley based on the laser ranging device provided by the embodiments of the present application is as follows: Figure 1 , Figure 2The diagram shows a frontal and top view of an inertial navigation trolley when the CPIII control point is facing the left side of a large-mileage inertial navigation system (INS). The measuring device includes an INS trolley 1 mounted on track 9, a laser rangefinder 5, a computer 4, and an INS 2 located above the INS trolley 1. The INS trolley 1 includes three running wheels (E, F, G) and one guide wheel H; the three running wheels and one guide wheel ensure that the INS trolley can travel along track 9. It also includes a CPIII control stake 8 located on one side of track 9, with a pre-drilled hole for inserting a target scale 6, which is inserted into the hole and parallel to the laser beam emitted by the laser rangefinder 5. The laser rangefinder 5 is installed perpendicular to the direction of travel of the INS trolley 1 and facing the CPIII control point, with its installation height slightly higher than the height of the CPIII control point.

[0047] The laser rangefinder 5 is horizontally mounted at point A in the middle of the inertial navigation trolley 1. Its laser beam emission direction is perpendicular to the trolley's travel direction, facing the side where the CPIII control point is located, and parallel to the tread surface of the trolley's wheels, ensuring that the horizontal angle of the laser beam is always the same as the horizontal angle of the track surface. The laser rangefinder is mounted on a vertically positioned support rod. The installation height h1 of the laser rangefinder should be freely adjustable. Before use, the laser rangefinder should be adjusted to a suitable height so that the laser beam can illuminate the middle of the target scale placed at the top of the CPIII control point C. B represents the position of the light spot in the target scale, and h2 is the height of the light spot in the target scale. When the horizontal angle of the track at the stored position of the trolley is zero, the height of point A is equal to the height of point B. This ensures that the laser beam emitted by the laser rangefinder can illuminate the surface of the target scale 6 placed above the CPIII embedded part 7 at the CPIII control point. The installation height of the laser rangefinder should be directly readable through the height scale on the support column.

[0048] The inertial navigation vehicle is equipped with an inertial navigation system and a computer. The inertial navigation system is connected to the computer via a data cable and outputs measurement data such as the azimuth angle, tilt angle and roll angle of the inertial navigation vehicle in real time. The laser rangefinder is connected to the computer via a data cable and outputs slant distance measurement data in real time.

[0049] like Figure 3 As shown, the target ruler adopts a rectangular sheet structure with graduations. In one embodiment, the target ruler with graduations has a rectangular sheet shape with a length of about 30cm and a width of about 3cm, and is made of stainless steel. The bottom of the target ruler is equipped with a cylinder with a length of about 5cm and a diameter of the same as the hole diameter of the CPIII control pile pre-embedded part, which can be vertically inserted into the hole of the CPIII control pile pre-embedded part set on the top of the retaining wall. The bottom of the target ruler is in contact with the top surface of the CPIII control pile pre-embedded part. The surface of the target ruler has metric graduations for directly reading the height difference between the laser spot and the top of the CPIII control pile pre-embedded part. The graduation at the bottom of the target ruler is zero.

[0050] likeFigure 4 As shown in another embodiment, the target ruler has a rectangular sheet shape with a length of about 40 cm and a width of about 3 cm, and is made of stainless steel material; a cylindrical body with a length of about 5 cm and a diameter same as that of the CPIII control pile embedded member hole is arranged at the middle of the back of the target ruler, and can be transversely inserted into the CPIII control pile embedded member hole arranged horizontally outside the CPIII control pile; the surface of the target ruler is provided with a metric scale, which is used for reading the height difference of the laser spot from the CPIII embedded member; and the scale at the middle of the target ruler corresponding to the center position of the embedded member hole is zero.

[0051] As shown in another embodiment, the target ruler has a rectangular sheet shape with a length of about 40 cm and a width of about 3 cm, and is made of stainless steel material; a cylindrical body with a length of about 5 cm and a diameter same as that of the CPIII control pile embedded member hole is arranged at the middle of the back of the target ruler, and can be transversely inserted into the CPIII control pile embedded member hole arranged horizontally outside the CPIII control pile; the surface of the target ruler is provided with a metric scale, which is used for reading the height difference of the laser spot from the CPIII embedded member; and the scale at the middle of the target ruler corresponding to the center position of the embedded member hole is zero. Figure 5 As shown in another embodiment, the target ruler has a rectangular sheet shape with a length of about 40 cm and a width of about 3 cm, and is made of stainless steel material; a cylindrical body with a length of about 5 cm and a diameter same as that of the CPIII control pile embedded member hole is arranged at the middle of the back of the target ruler, and can be transversely inserted into the CPIII control pile embedded member hole arranged horizontally outside the CPIII control pile; the surface of the target ruler is provided with a metric scale, which is used for reading the height difference of the laser spot from the CPIII embedded member; and the scale at the middle of the target ruler corresponding to the center position of the embedded member hole is zero.

[0052] Step 1, the inertial navigation car 1 equipped with inertial navigation 2, odometer 3, computer 4 and laser range finder 5 is driven to the vicinity of the CPIII control point parallelly, and parked; wherein the laser range finder is horizontally fixed on the vertically arranged support rod at the middle of the car frame of the inertial navigation car.

[0053] Step 2, the measuring personnel vertically or horizontally inserts a target ruler 6 facing the track direction into the CPIII embedded hole of the CPIII control point CPIII embedded member 7 arranged on the top surface of the ballast retaining wall 8.

[0054] Step 3, the measuring personnel slowly pushes the inertial navigation car to make the laser beam emitted by the laser range finder 5 align with the central axis of the target ruler 6 vertically arranged on the CPIII control point C position, and then parks.

[0055] The direction of the laser beam emitted by the laser range finder should be perpendicular to the running direction of the inertial navigation car, and parallel to the tread surface of the running wheel of the inertial navigation car to the side of the CPIII control point; the laser range finder should be parallel to the bottom surface of the running wheel of the inertial navigation car, so that the horizontal angle of the laser beam is always the same as the horizontal angle of the track surface, which can be measured by the roll angle γ output by the inertial navigation; the laser beam should be parallel to the base surface of the inertial navigation car; the installation angle of the laser range finder is fixed, and the height is adjustable and provided with a scale for manually reading the actual installation height of the laser range finder. Before use, the height of the laser range finder should be adjusted to the middle position of the target ruler arranged above the CPIII control pile, and the actual installation height of the laser range finder is read from the scale.

[0056] Step 4, the height difference h2 of the laser beam spot B on the scale of the target ruler 6, the CPIII control point number and the installation height h1 of the laser range finder are manually read, and the read data is input into the computer 4 of the inertial navigation car; the computer of the inertial navigation car 1 obtains the elevation of the laser beam spot on the scale of the target ruler, the CPIII control point number and the installation height of the laser range finder.

[0057] Step 5: Store the CPIII control point data file containing the serial number, identification number, mileage, plane coordinates (X, Y), and elevation (H) of all CPIII control points. The control point file is in CSV format and can be edited using general editing software or Excel. Before measurement, the control point file should be imported into the inertial navigation trolley computer via USB flash drive. The inertial navigation trolley computer extracts the mileage (M) of CPIII control point C from the internally stored CPIII project file based on the manually entered CPIII point number. C Plane coordinates X C Y C and elevation H C Combining manually input elevation h2, laser rangefinder installation height h1, slant distance L between point A and spot B of the inertial navigation trolley measured by laser rangefinder 5, azimuth angle Ψ, tilt angle θ, and roll angle γ transmitted by inertial navigation 2, the plane coordinates X of the track centerline point D are calculated using trigonometric functions. D Y D and elevation H D .

[0058] The computer is connected to the inertial navigation system via a serial data cable to receive measurement data output by the inertial navigation system in real time, including azimuth angle Ψ, tilt angle θ, and roll angle γ.

[0059] A laser rangefinder measures the distance between the center of the inertial navigation vehicle (INS) and the target scale. The three-dimensional coordinate measurement of the track center point parallel to the CPIII control point is decomposed into the measurement of the azimuth, tilt, and roll angles between the observation point and the CPIII control point, as well as the measurement of longitudinal, lateral, and vertical distance components. The three-dimensional coordinate measurement of the track center point parallel to the CPIII control point is further decomposed into the measurement of three angles and three distance components between the observation point and the CPIII control point, and the reading of the laser spot position on the target scale surface. Based on the three angles and three distances and the known three-dimensional coordinates of the CPIII control point, using the computer configured on the INS and trigonometric function algorithms, the plane coordinates and elevation of the track center point parallel to the CPIII control point can be calculated.

[0060] The three angles refer to the azimuth, tilt, and roll angle of the track. These can be provided by the inertial navigation system on the inertial navigation trolley, or extracted in advance from the design drawings and stored in the document along with the coordinates of the CPIII control points for real-time retrieval.

[0061] The three distances refer to the longitudinal, lateral, and vertical distances of the reference track between the control point and the observation point. The longitudinal distance can be reduced to zero by moving the inertial navigation trolley to a position parallel to the CPIII control point; the lateral distance is measured by a laser rangefinder installed in the middle of the inertial navigation trolley; and the vertical distance is measured by a target scale vertically placed above the CPIII control point.

[0062] The basic principle of the application is that a target ruler is vertically arranged above the CPIII control point, the slant distance L and the inclination angle γ between the device point A and the target spot B are measured by using a laser measuring device, the spot height difference h2 and the installation height hi of the laser measuring device point A are combined, the planar coordinates (X C , Y C ) and H C of the CPIII control point C are known, and the direction angle Ψ, the inclination angle θ and the roll angle γ of the location where the track is located are used to calculate the planar coordinates (X D , Y D ) and the elevation H D of the track center point D by using a trigonometric function calculation method.

[0063] In order to clearly show the geometric relationship among points A, B, C and D, the transverse section, the longitudinal section and the horizontal section are used to abstractly show the schematic diagram, and the direction angle Ψ, the inclination angle θ and the roll angle γ are zero and not zero respectively.

[0064] Fig. 6 (a) and (b) abstractly show the laser measuring device point A, the target spot point B, the CPIII control point C, the track center point D, the measurement slant distance L and the laser beam inclination angle γ, the slant distance L, and the projection points A', B', C' and D' of points A, B, C and D and the projection length L' in the horizontal reference plane. Among them, Fig. 6 (a) shows the case when the superelevation and the slope of the track are both zero. At this time, the projection point A' overlaps with the projection point D', and the projection point B' overlaps with the projection point C', and the relationship among the elevations of the four points is:

[0065] H A = H D + hi (1)

[0066] H B = H C + h2 (2)

[0067] H A = H B (3)

[0068] The elevation of the D point is derived from the formula (1), (2) and (3) as follows:

[0069] H D = H C + h2-h1 (4)

[0070] Fig. 6 (b) abstractly shows the transverse section geometric relationship when the slope and the superelevation of the track line are not equal to zero, and the inclination angle θ and the roll angle γ output by the inertial navigation are not equal to zero. At this time, the height HA H B , the projection point A' and D' do not overlap, but B' and C' overlap, and the height relationship between the points is:

[0071] H A = H D + h1-cosγ (5)

[0072] H B = H A + L-sinγ (6)

[0073] H B = H c + h2 (7)

[0074] The height of point D is derived from equations (5), (6), and (7):

[0075] H D = H C + h2-h1-cosγ-L-sinγ (8)

[0076] In order to facilitate the determination of the planar coordinates of the track center point, Figure 7(a) shows the geometric relationship between the laser measurement device measurement point A and the track center line measurement point D in the vertical section without considering the influence of the longitudinal slope gradient. The rail top surface in the straight line section is parallel to the horizontal reference surface, and the track center point D and the projection point A' overlap. The planar coordinates X D , Y D of point D are equal to the planar coordinates X A , Y A of point A. The height difference between points A and D is h2.

[0077] Figure 8(a) abstractly shows the geometric relationship when the CPIII reference point is located on the left side of the track, when the track line azimuth is Ψ, and is in a flat slope state, and the superelevation is zero, the AC line horizontal distance is L, the azimuth is 90°+Ψ, and the planar projection of A and the track center point D coincides. The geometric relationship between the planar coordinates of point D and the C reference point is:

[0078] X D = X C + ΔX = X C + L-sin(90+Ψ) = X C + L-cosΨ (9)

[0079] Y D = Y C + ΔY = Y C + L-cos(90+Ψ) = Y C - L-sinΨ (10)

[0080] Figure 8(a) shows the geometric relationship when the CPIII reference point is located on the left side of the track, the track line azimuth is Ψ, and the horizontal angle γ is not zero, the AC line horizontal distance is L' = L-cosγ, and the point A coincides with the planar projection of the track center point D.

[0081] X D = X C + L' - cos Ψ = X C + L-cosγ-cosΨ (11)

[0082] Y D = X C - L' - sin Ψ = X C - L-cosγ-sinΨ (12)

[0083] Figure 7(b) shows the geometric relationship when the CPIII reference point is located on the left side of the track, the track line azimuth is Ψ, and the horizontal angle γ is not zero, the AC line horizontal distance is L', the azimuth is 90°+Ψ, and the point A is different from the planar projection of the track center point D by ΔM.

[0084] ΔM = h1-sinθ (13)

[0085] The D point mileage is:

[0086] M D = M C - h1-sinθ (14)

[0087] The projection height of the point A to the track plane is:

[0088] h'1 = h1-cosθ (15)

[0089] Figure 8(b) shows the geometric relationship between the laser measurement device point A, the projection point A' of the point A in the track top surface, the projection length L', the track direction angle Ψ, and the track center line point D in the horizontal plane. The geometric relationship between the D point planar coordinates and the C reference point is:

[0090] X D = X C + ΔX + ΔM-sin Ψ = X C + L' - cos Ψ + ΔM-sin Ψ (16)

[0091] Y D = Y C - ΔY - ΔM-cos Ψ = Y C - L' - sin Ψ - ΔM-cos Ψ (17)

[0092] Substitute formula (13) into formula (16) and (17), deduce the plane coordinate calculation formula of point D:

[0093] X D = X C +(L*cosγ-h1*cosγ)*cosΨ+h1*cosθ*sinΨ (18)

[0094] Y D = Y C -(L*cosγ-h1*cosγ)*sinΨ-h1*cosθ*cosΨ (19)

[0095] Substitute formula (13) into formula (5) to obtain the elevation calculation formula of point D:

[0096] H D = H C +h2-h1*cosθ*cosγ-L*sinγ (20)

[0097] In the formula, X D , Y D are the plane coordinates of CPIII control points; L is the slant distance; γ is the roll angle; Ψ is the azimuth angle; θ is the inclination angle; L is the slant distance; h1 is the installation height of the laser range finder.

[0098] Up to now, the mileage M D , the plane coordinates X D , Y D and the elevation H D of the parallel and CPIII control point track line center line D can be calculated, which are further used for further fusion calculation with inertial navigation data and GNSS data to obtain higher-precision track shape and unevenness measurement results.

[0099] The application is not limited to three-dimensional coordinate measurement for track azimuth angle, inclination angle and roll angle inertial navigation trolley equipped with high-precision inertial navigation equipment, and can also be used for detection systems combined with inertial measurement unit (IMU) and GNSS-RTK or low-cost detection systems equipped with only GNSS-RTK. Since the IMU cannot output the azimuth angle, inclination angle and roll angle of the track line, the measurement coordinates (X i , Y i , H i ) and (X i-1 , Y i-1 , H i-1 ) of two groups of GNSS-RTK with a distance of more than 5 meters can be used to calculate the azimuth angle Ψ and the inclination angle θ of the track line near the measurement point, and the lateral acceleration a x and the vertical acceleration a z output by the IMU are used to calculate the roll angle γ of the current track:

[0100]

[0101]

[0102]

[0103] Furthermore, when inertial navigation and GNSS-RTK conditions are lacking, the direction angle Ψ given in the route design drawing can be used directly. 设计 Inclination angle θ 设计 and roll angle γ 设计 The location calculation is performed by first calculating the track azimuth angle Ψ corresponding to each CPIII control point based on the design route or ledger data. 设计 Inclination angle θ 设计 and roll angle γ 设计 This information, along with the CPIII control point's number, mileage, horizontal coordinates, and elevation, is stored in the CPIII control point data file. During the measurement process, the computer can directly read the CPIII control point number entered manually.

[0104] It should be noted that, depending on the implementation needs, each step / component in this invention can be broken down into more steps / components, or two or more steps / components or parts of the operation of a step / component can be combined into a new step / component to achieve the purpose of this invention.

[0105] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Those skilled in the art can make variations and modifications to the present invention using the methods and techniques disclosed above, or modify it into equivalent embodiments with equivalent changes, without departing from the spirit and technical solution of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention's technical solution, shall still fall within the protection scope of the present invention's technical solution.

Claims

1. A three-dimensional coordinate measurement method for a laser range finder-based inertial navigation trolley, characterized in that, The application relates to a method for measuring the three-dimensional coordinates of a track center point. The inertial navigation trolley is moved to the vicinity of the CPIII control point in parallel to the track, and is parked; A target scale is vertically or horizontally inserted into the pre-embedded hole of the CPIII control point; The inertial navigation trolley is moved, and is parked after the laser beam emitted by the laser range finder is aligned with the axis of the target scale; The elevation of the laser beam spot in the scale of the target scale and the number of the CPIII control point are manually read, and the elevation of the laser beam spot in the scale of the target scale, the number of the CPIII control point and the installation height of the laser range finder are input into the computer of the inertial navigation trolley; The computer of the inertial navigation trolley extracts the mileage, plane coordinates and elevation of the CPIII control point from the CPIII engineering file according to the number of the CPIII control point, and calculates the plane coordinates and elevation of the track center point according to the elevation of the target scale, the installation height of the laser range finder, the slant distance between the inertial navigation trolley and the laser beam spot measured by the laser range finder, the azimuth angle, the inclination angle and the roll angle sent by the inertial navigation.

2. The three-dimensional coordinate measurement method of the laser range finder-based inertial navigation trolley according to claim 1, characterized in that, The installation direction of the laser range finder is perpendicular to the moving direction of the inertial navigation trolley and faces the CPIII control point side, and the installation height of the laser range finder is higher than the height of the CPIII control point pre-embedded part.

3. The three-dimensional coordinate measurement method of the laser range finder-based inertial navigation trolley according to claim 1, characterized in that, The emission direction of the laser beam emitted by the laser range finder is perpendicular to the moving direction of the inertial navigation trolley and is parallel to the tread surface of the moving wheel of the inertial navigation trolley, so that the horizontal angle of the laser beam is always the same as the horizontal angle of the track surface.

4. The three-dimensional coordinate measurement method of the laser range finder-based inertial navigation trolley according to claim 1, characterized in that, The laser range finder measures the distance between the center of the inertial navigation trolley and the target scale, and decomposes the measurement of the three-dimensional coordinates of the track center point in parallel to the CPIII control point position into the measurement of the azimuth angle, the inclination angle and the roll angle between the observation point and the CPIII control point, and the longitudinal distance, the lateral distance and the vertical distance components; The azimuth angle, the inclination angle and the roll angle are measured by the inertial navigation, the lateral distance and the vertical distance are measured by using one laser range finder and one target scale, and the longitudinal distance is adjusted to zero by moving the inertial navigation trolley.

5. The three-dimensional coordinate measurement method of the laser range finder-based inertial navigation trolley according to claim 4, characterized in that, The plane coordinates of the track center point at the position of the inertial navigation trolley are calculated by the following formula: wherein L is the slant range; and is the roll angle; and is the tilt angle; L is the slant range; and h1 is the installation height of the laser range finder.

6. The three-dimensional coordinate measurement method of the laser range finder-based inertial navigation trolley according to claim 5, characterized in that, The elevation of the track center point at the position of the inertial navigation trolley is calculated by the following formula: wherein is the elevation; is the elevation of the CPIII control point position point C, and h2is the height of the spot in the target scale.

7. The three-dimensional coordinate measurement method of claim 5, wherein, The inertial navigation adopts a combined measurement mode of an inertial measurement unit (IMU) and GNSS, and calculates an azimuth angle Ψ, an inclination angle and a roll angle using two sets of GNSS plane coordinates at a certain distance from each other The inertial measurement unit (IMU) outputs a lateral acceleration and a vertical acceleration According to the following formula wherein , are two sets of GNSS plan coordinates at a distance from each other; are two sets of elevations at a distance from each other.

8. A laser range finder based inertial navigation trolley three dimensional coordinate measuring apparatus according to any one of claims 1 to 7, wherein, The application further relates to an inertial navigation trolley device for measuring the three-dimensional coordinates of a track center point.

9. The laser range finder based inertial navigation trolley three-dimensional coordinate measuring apparatus according to claim 8, characterized in that, The target scale is in the shape of a rectangular sheet with scales, and the bottom of the target scale is provided with a cylindrical body with the same diameter as the pre-embedded hole of the CPIII control pile, and the target scale is horizontally inserted into the pre-embedded hole outside the CPIII control pile.

10. The laser range finder based inertial navigation trolley three-dimensional coordinate measuring apparatus according to claim 8, characterized in that, The target scale is in the shape of a rectangular sheet with scales, and the bottom of the target scale is provided with a cylindrical body with the same diameter as the pre-embedded hole of the CPIII control pile, and the target scale is horizontally inserted into the pre-embedded hole outside the CPIII control pile. The target scale is in the shape of a rectangular sheet with scales, and the bottom of the target scale is provided with a cylindrical body with the same diameter as the pre-embedded hole of the CPIII control pile, and the target scale is horizontally inserted into the pre-embedded hole outside the CPIII control pile.

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