Calibration method for orthogonal-motion detection apparatus

Abstract

A calibration method for an orthogonal-motion detection apparatus, which relates to the technical field of detection apparatus calibration. The method comprises an application-field calibration method and a manufacturing-factory calibration method. The field calibration comprises: using a mounting bracket to fix a detection apparatus in an application field, and using a field calibration tool to perform calibration; and after removing the field calibration tool, connecting a center hole of a joint of a sliding rod to an object subjected to measurement, and on the basis of calibration parameters, calculating the real-time coordinates of the center hole of the joint of the sliding rod in an established rectangular coordinate system, wherein the change in the coordinate value of the real-time coordinates is a change in the position of said object. The manufacturing-factory calibration comprises: using a manufacturing-factory calibration tool with an anti-rotation structure to fix a detection apparatus and perform calibration; and removing the detection apparatus, and mounting the detection apparatus in an application field by means of a mounting bracket, and then connecting a center hole of a joint of a sliding rod to an object subjected to measurement, and performing measurement. The calibration method for a detection apparatus is provided, and a solution for the separation of a calibration place and an application place is provided, thereby effectively reducing errors in secondary positioning.

Description

A calibration method for an orthogonal motion detection device Technical Field

[0001] The present invention relates to the technical field of detection device calibration, and in particular to a calibration method for an orthogonal motion detection device. Background Art

[0002] Applications require monitoring of the movement of the point rail and center rail, as well as the parameters and status of their contact with the stock rail, wing rail, or both. Several monitoring methods and equipment have been proposed. Among them, Dalian University of Technology and Xi'an Railway Signal Co., Ltd. have each proposed converting the movement of the point rail into a composite motion of rotation and sliding. Based on the detected rotational and sliding parameters, the projections of the point rail in the direction along the stock rail or wing rail and in the orthogonal direction perpendicular to the direction of the stock rail or wing rail are calculated. In other words, the movement of the point rail is equivalent to a composite motion in predetermined orthogonal directions.

[0003] In the prior art, Dalian University of Technology has proposed a calculation method for an integrated real-time measurement device for the longitudinal creep and close clearance of a point rail, with invention patent application number CN201910630367.4. Specifically, calibration is first performed. The calibration model is constructed based on the law of cosines and a search method. Based on the displacement data obtained from two calibration positions, an equation is established with the eccentricity a between the axis of the action guide rod and the axis of the rotating shaft as the only unknown parameter. The design value a0 of the eccentricity is used as the initial value. Through continuous optimization using the search method, a theoretical value a of the eccentricity that meets the accuracy requirements is obtained, and calculations can then begin.

[0004] Xi'an Railway Signal Co., Ltd. has developed a device for converting orthogonal compound motion into sliding and rotating motion, and a motion parameter detection device. The device converts the motion of the point rail or center rail into a compound motion of rotation and linear motion and realizes the detection output of rotation angle and linear displacement. The invention patent number is CN202311488340.9. Specifically, the device for converting orthogonal compound motion into sliding and rotating motion includes a base, a bearing fixed inside the base, and a rotating shaft inside the bearing; the bottom of the rotating shaft extends to the outside of the base, and the portion located outside the base is penetrated by a transverse hole in the horizontal direction, and a sliding rod is provided inside the transverse hole through a sliding assembly for horizontal sliding; one end of the sliding rod is connected to a joint bearing, and the joint bearing hole is connected to the test piece; the bottom of the rotating shaft is provided with a groove in the vertical direction that divides the transverse hole into two sections, and an anti-rotation block is fixed in the groove to abut the sliding rod; when the test piece performs horizontal orthogonal compound motion, the joint bearing converts the orthogonal compound motion of the test piece into sliding of the sliding rod in the transverse hole and rotation of the rotating shaft. The detection device includes a magnetic grid for detecting the sliding displacement of the sliding rod in the transverse hole and a magnetic column for detecting the rotation angle of the rotating shaft; the magnetic grid is fixedly set on the sliding rod, and the magnetic grid is parallel to the axis of the transverse hole. The device is also provided with a first sensor aligned with the magnetic grid, and the first sensor is used to detect the sliding displacement of the magnetic grid; the magnetic column is fixedly set on the axis of the rotating shaft, and a second sensor opposite to it is fixed above it, and the second sensor is used to detect the rotation angle of the magnetic column. The orthogonal motion parameters of the measured object are calculated by the rotation angle of the magnetic column and the sliding displacement of the magnetic grid. The company also proposed a method suitable for detecting the orthogonal displacement of orthogonal composite moving objects. The displacement of the point rail or the center rail on the orthogonal axis is calculated by the detected rotation angle and linear displacement data. The invention patent application number is 202310779837.X.

[0005] All of the above calculation methods require calibration before starting continuous measurement. The calibration models are based on the law of cosines, which calculate the required parameters. Orthogonal displacement calculations are then performed based on these parameters. During the parameter calculation process, the law of cosines is used to construct an equation for the distance from the initial point to the origin, forming a quadratic equation. After solving the equation, the correct solution is determined and selected.

[0006] However, solving quadratic equations involves square root calculations, which limits software programming. The correct solution may be selected incorrectly, leading to errors in subsequent measurement and calculation results. Secondly, due to secondary positioning errors during calibration and installation, whether the calibration parameters can be correctly transferred to the user state depends on the measurement and calculation methods, as well as the fixed installation method. The measurement method is determined by the selected sensor, which can be either absolute or relative. Relative sensors can cause deviations between the calibration and measurement benchmarks. If the calibration and calculation methods are closely related to the fixed position of the detection device, secondary positioning errors may also lead to significant deviations in the results. Summary of the Invention

[0007] To solve the above problems, the present invention provides a calibration method for an orthogonal motion detection device. The present invention provides a calibration method based on a detection device previously applied for, provides a solution for separating the calibration site and the application site, can quickly perform calibration, and effectively reduce secondary positioning errors.

[0008] To achieve the above objectives, the present invention provides the following technical solutions.

[0009] The present invention provides a calibration method for an orthogonal motion detection device, including an application site calibration method and a manufacturing plant calibration method.

[0010] The on-site calibration method includes the following steps:

[0011] Use a mounting bracket to fix the detection device on the measurement reference;

[0012] The on-site calibration tool is installed and fixed in an appropriate position relative to the measurement reference; the on-site calibration tool includes a calibration fixture and a calibration plate; the calibration fixture is used to fix the calibration plate, and the calibration plate has at least two calibration points. The direction of the line connecting the calibration points is perpendicular or parallel to the measurement direction of interest, or maintains a specified angle;

[0013] The sliding rod in the detection device is retracted to the limit position, the detection device is powered on, the two sensors are activated, and the sliding rod is extended so that the center hole of the sliding rod joint is connected to the two calibration points respectively. The two sensors respectively obtain the displacement of the center hole of the sliding rod joint from the limit position to the two calibration points, as well as the two rotation angles measured by the rotation angle sensor;

[0014] Construct a rectangular coordinate system with the rotation angle sensor axis as the coordinate origin and the focus direction as the coordinate axis. Based on the displacement of the sliding rod joint center hole from the extreme position to the two calibration points and the two rotation angles, obtain the distance from the sliding rod joint center hole to the coordinate origin and the angle between the rotation angle sensor zero angle and the coordinate axis when the sliding rod is at the extreme position as calibration parameters to complete the calibration.

[0015] Remove the on-site calibration tooling, connect the center hole of the sliding rod joint to the object to be measured, and calculate the real-time coordinates of the center hole of the sliding rod joint in the established rectangular coordinate system. The change in the coordinate value of the real-time coordinate is the measured value of the position change of the object to be measured.

[0016] The manufacturing plant calibration method includes the following steps:

[0017] The detection device and mounting bracket have interlocking anti-rotation structures that restrict them to fixed relative positions. The calibration fixture at the manufacturing plant has the same anti-rotation structure and detection device mounting structure as the mounting bracket, and has at least two calibration points. Using the mounted detection device as a reference, the connection between the calibration points is parallel, perpendicular, or at a specified angle to the intended application area.

[0018] The detection device is fixedly installed on the calibration fixture of the manufacturing plant, the sliding rod in the detection device is retracted to the limit position, the detection device is powered on, the two sensors are activated, the sliding rod is extended, and the center hole of the sliding rod joint is connected to the two calibration points respectively. The two sensors respectively obtain the displacement of the center hole of the sliding rod joint from the limit position to the two calibration points, as well as the two rotation angles measured by the rotation angle sensor;

[0019] Construct a rectangular coordinate system with the rotation angle sensor axis as the coordinate origin and the focus direction as the coordinate axis. Based on the displacement of the sliding rod joint center hole from the extreme position to the two calibration points and the two rotation angles, obtain the distance from the sliding rod joint center hole to the coordinate origin and the angle between the rotation angle sensor zero angle and the coordinate axis when the sliding rod is at the extreme position as calibration parameters to complete the calibration.

[0020] The detection device is removed from the calibration tooling at the manufacturing plant and fixedly installed on the mounting bracket at the installation application site. The sliding rod in the detection device is retracted to the limit position, the detection device is powered on, the two sensors work, the center hole of the sliding rod joint is connected to the object to be measured, and the real-time coordinates of the center hole of the sliding rod joint are calculated in the established rectangular coordinate system. The change in the coordinate value of the real-time coordinate is the measured value of the position change of the object to be measured.

[0021] Preferably, the object to be measured is a switch rail or a point rail;

[0022] When performing calibration on site, the detection device is fixedly mounted on the outside of the stock rail or wing rail using the mounting bracket. The on-site calibration tool is installed and fixed on the stock rail or wing rail during the calibration process to perform on-site calibration. After calibration, the on-site calibration tool is removed, the center hole of the sliding rod joint is connected to the measured point rail or heart rail, and the displacement of the measured heart rail or point rail is determined according to the calibration parameters.

[0023] When the manufacturing plant performs calibration, the manufacturing plant calibration fixture with an anti-rotation structure is used to fix the detection device and calibrate it. After calibration, the detection device is installed on the base rail or wing rail through a mounting bracket with the same anti-rotation structure, and the center hole of the sliding rod joint is connected to the point rail or heart rail to be measured to measure the position change.

[0024] Preferably, the calculation of the distance from the center hole of the sliding rod joint to the coordinate origin and the angle between the zero angle of the angle sensor and the coordinate axis when the sliding rod is at the extreme position according to the calibration algorithm includes the following steps:

[0025] Construct a coordinate system with the base rail or wing rail direction as the X-axis, the rotation center of the detection device as the coordinate origin, and the Y-axis perpendicular to the base rail or wing rail. The direction of the line connecting the two calibration points is parallel to the coordinate axis X-axis. Then, the Y coordinates of the two calibration points are equal in the calibrated coordinate system, and the difference in the X coordinates is equal to the distance between the two calibration points.

[0026] The rotation center of the detection device is set to O. The distance from the rotation center O of the detection device to the center hole of the sliding rod joint when the sliding rod is at the retracted limit position is R. The calibration points are A and B, and the distance is m. When the center hole of the sliding rod joint moves to A and B, the displacement relative to the retracted limit position is L1 and L2 respectively. The angle values ​​measured by the angle sensor are α1 and α2 respectively. Then, if the angle zero position of the angle sensor is OP and is located between the X-axis and OB, then ∠POA=α1, ∠POB=α1, and the angle between the angle zero position of the angle sensor and the direction of the base rail or wing rail is the angle β between OP and the X-axis;

[0027] According to the law of sine: (L1+R) / sin(β+α2)=m / sin(α1-α2)=(L2+R) / sin(180°-(β+α1))

[0028] That is: m*sin(β+α2)=(L1+R)*sin(α1-α2) m*sin(180°-(β+α1))=(L2+R)*sin(α1-α2)

[0029] According to the projection relationship of OA and OB on the X-axis and Y-axis, (L2+R)*sin(β+α2)=(L1+R)*sin(β+α1) (L2+R)*cos(β+α2)=m+(L1+R)*cos(β+α1)

[0030] In addition: sin(β+α2)=sinβcos(α2)+cosβsin(α2) sin(β+α1)=sinβcos(α1)+cosβsin(α1) cos(β+α2)=cosβcos(α2)-sinβsin(α2) cos(β+α1)=cosβcos(α1)-sinβsin(α1)

[0031] Then: m*sin(180°-(β+α1))=(L2+R)*sin(α1-α2) m*sin(β+α2)=(L1+R)*sin(α1-α2)

[0032] Subtracting both sides of the equal sign, we get: m*(sin(β+α1)-sin(β+α2))=(L2-L1)*sin(α1-α2)

[0033] Then: m*(2cos((2*β+α1+α2) / 2)sin((α1-α2) / 2)=(L2-L1)*sin(α1-α2) cos((2*β+α1+α2) / 2)=(L2-L1)*sin(α1-α2) / (2*m*sin((α1-α2) / 2))

[0034] Then: β+(α1+α2) / 2=2kπ±arccos((L2-L1)*sin(α1-α2)) / (2*m*sin((α1-α2) / 2)))

[0035] Then, the calculation formula for the angle β between the zero position of the angle sensor and the direction of the base rail or wing rail is: β=2kπ±arccos((L2-L1)*sin(α1-α2) / (2*m*sin((α1-α2) / 2)))-(α1+α2) / 2

[0036] Among them, 0°≤β≤90°;

[0037] The calculation formula for R is obtained according to m*sin(β+α2)=(L1+R)*sin(α1-α2) or m*sin(180°-(β+α1))=(L2+R)*sin(α1-α2).

[0038] Preferably, the calculation of the distance from the center hole of the sliding rod joint to the coordinate origin and the angle between the zero angle of the angle sensor and the coordinate axis when the sliding rod is at the extreme position according to the calibration algorithm includes the following steps:

[0039] Construct a coordinate system with the base rail or wing rail direction as the X-axis, the rotation center of the detection device as the coordinate origin, and the Y-axis perpendicular to the base rail or wing rail. The Y coordinates of the two calibration points are equal in the calibrated coordinate system, and the difference in X coordinates is equal to the distance between the two calibration points.

[0040] The rotation center of the detection device is set to O. The distance from the rotation center O of the detection device to the center hole of the sliding rod joint when the sliding rod is at the retracted limit position is R. The calibration points are A and B, and the distance is m. When the center hole of the sliding rod joint moves to A and B, the displacement relative to the retracted limit is L1 and L2 respectively. The angle values ​​measured by the angle sensor are α1 and α2 respectively. Then, if the angle zero position of the angle sensor is OP and is located between the X-axis and OB, then ∠POA=α1, ∠POB=α1, and the angle between the angle zero position of the angle sensor and the direction of the base rail or wing rail is the angle β between OP and the X-axis;

[0041] Construct a circle with OA as its diameter and determine that the point of intersection of this circle and OB is C; in triangle ABC, ∠BAC = ∠a, ∠ACB = ∠c, and ∠ABC = ∠b;

[0042] Using the law of sines:

[0043] Then, the three internal angles in the triangle are: ∠b=α2+β

[0044] Substituting into the sine formula we get:

[0045] According to the trigonometric function formula sin(90°+α)=cosα, sin(90°-α)=cosα, the formula changes to:

[0046] Where, 0°≤β≤90°; the calculation formula for the angle β between the zero position of the angle sensor and the direction of the base rail or wing rail is obtained from the above formula;

[0047] The calculation formula for R is obtained according to m*sin(β+α2)=(L1+R)*sin(α1-α2) or m*sin(180°-(β+α1))=(L2+R)*sin(α1-α2).

[0048] Preferably, if the angle zero position OP of the angle sensor is not between the X-axis and OB, the angle zero position of the angle sensor is rotated to meet the requirements, and physical angle rotation or numerical compensation is performed; wherein, the numerical compensation method is to subtract the angle value to be rotated from the output angle of the angle sensor. After the angle sensor is powered off and then powered on again, if the rotated angle zero position cannot be maintained, the angle of the angle zero position needs to be recorded in the software, and in subsequent calculations, it needs to be used as a calculation parameter together with the angle β between the angle zero position of the angle sensor and the direction of the basic track or wing track.

[0049] Preferably, the on-site calibration tool is installed and fixed on the basic rail or wing rail during the calibration process; the on-site calibration tool includes a hook head assembly and a calibration plate; the hook head assembly is clamped to the basic rail or wing rail, and the calibration plate is located on the other side of the basic rail or wing rail; the hook head assembly includes a calibration hook head, a hook head bolt and a nut; when in use, the calibration hook head and the hook head parts of the hook head bolt are respectively close to the two sides and the rail bottom of the basic rail or wing rail, the bolt part of the hook head bolt passes through the calibration hook head, and the end of the bolt part of the hook head bolt is fixed to the calibration hook head through the nut; the calibration plate is an L-shaped or T-shaped component; one side of the calibration plate is detachably fixed to the calibration hook head, and the other side is provided with calibration points, and the connecting direction of the calibration points is parallel to the extension direction of the basic rail or wing rail.

[0050] Preferably, the base of the detection device is provided with an anti-rotation structure, which cooperates with the mounting bracket to prevent the detection device from rotating relative to the mounting bracket, and includes an anti-rotation slot or a positioning pin.

[0051] Preferably, the mounting bracket includes a mounting hook head and a mounting hook head bolt; when in use, the mounting hook head and the hook head parts of the mounting hook head bolt are respectively close to the two sides and the rail bottom of the basic rail or wing rail, the bolt part of the mounting hook head bolt passes through the mounting hook head, and the end of the bolt part of the mounting hook head bolt is fixed to the mounting hook head by a nut; a mounting plate extends outward from the mounting hook head; and a mounting hole for fixing the detection device is provided on the mounting plate.

[0052] Preferably, the calibration tooling includes a limit sleeve for limiting the sliding rod to be retracted to the extreme position. During the calibration process and on-site restoration process, when the sliding rod needs to be retracted to the extreme position, the limit sleeve is clamped on the outer periphery of the sliding rod and the limit sleeve is removed after completion.

[0053] Beneficial effects of the present invention:

[0054] The present invention proposes a calibration method for an orthogonal motion detection device, which is applicable to two scenarios. The first is on-site calibration, which uses an on-site calibration tool to achieve calibration after the detection device is installed on-site. After installation, the angle of the rotating shaft and the fixed part of the detection device relative to the base rail or wing rail is fixed. These parameters are calculated through calibration to avoid secondary positioning errors. The second is calibration in a laboratory or manufacturing plant using a manufacturing plant calibration tool. The tool has a fixed installation structure for the detection device and has the same anti-rotation structure as the mounting bracket of the detection device. After calibration is completed, the mounting bracket can be used to restore to the same fixed angle as during calibration at the application site, and the sliding rod can be restored to the retracted limit position. In this way, the calibration state can be restored on-site after calibration in the laboratory, avoiding calibration under harsh conditions on site and affecting the calibration accuracy, thereby shortening the on-site construction time. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG1 is a flow chart of a calibration process of an orthogonal motion detection device according to Embodiment 1 of the present invention;

[0056] FIG2 is a diagram showing the relationship between calibration parameters and sensor values ​​in Examples 1 and 2 of the present invention;

[0057] FIG3 is a schematic structural diagram of an on-site calibration tool according to Example 1 of the present invention;

[0058] FIG4 is a schematic diagram of the detection device of Example 1 of the present invention being calibrated using an on-site calibration tool after being installed on-site;

[0059] 5 is a schematic diagram of the assembly of the anti-rotation slot and the anti-rotation socket between the base of the detection device and the mounting bracket according to Example 1 of the present invention;

[0060] FIG6 is a schematic diagram of the detection device of Example 1 of the present invention being calibrated using a calibration tool at a manufacturing plant;

[0061] 7 is a diagram showing the relationship between calibration parameters and sensor values ​​when the angle zero position is located between the coordinate origin and the line connecting the two calibration points according to Example 3 of the present invention;

[0062] 8 is a diagram showing the relationship between calibration parameters and sensor values ​​when the line connecting the coordinate origin and the two calibration points is between the angle zero position and the positive direction of the X-axis in Example 3 of the present invention;

[0063] FIG9 is a schematic diagram of a mounting bracket for the anti-rotation bayonet.

[0064] In the figure: 1. Detection device; 1-1. Anti-rotation structure on the base of the detection device; 2. Mounting bracket; 2-1. Installing hook head; 2-2. Installing hook head bolt; 3. Sliding rod; 4. On-site calibration tooling; 4-1. Calibration plate; 4-2. Calibration hook head; 4-3. Hook head bolt; 4-4. Nut; 5. Calibration tooling at the manufacturing plant; 5-1. Anti-rotation structure on the calibration tooling at the manufacturing plant. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0066] Example 1

[0067] Since there are secondary positioning errors in calibration and installation, whether the calibration parameters can be correctly transferred to the use state is related to the measurement method, calculation method, and fixed installation method. The measurement method is determined by the selected sensor. The sensor includes absolute value sensors and relative value sensors. The relative value sensor may cause deviations in the calibration benchmark and the measurement benchmark. If the calibration and calculation method are closely related to the fixed position of the detection device, the secondary positioning error may also cause obvious result deviations. If the calibration is performed after the detection equipment is fixed and installed, and then the measurement and detection state is directly entered, there will be no secondary positioning error, and there will be no influence of the relative value sensor zero position change. In theory, a relatively ideal result can be obtained, but in actual operation, there are still difficulties that are difficult to overcome. For example, on-site calibration is inconvenient, the operation is difficult, and the calibration accuracy is poor, which affects the accuracy of subsequent measurements. To this end, a calibration method for an orthogonal motion detection device of the present invention, the specific process is shown in Figure 1. The calibration object in this embodiment, that is, the detection device, is the same as the structure and working principle of the previously applied Chinese patent CN202311488340.9. This embodiment specifically includes the following steps:

[0068] S1: Use a mounting bracket to fix the detection device 1 on the outside of the stock rail or wing rail.

[0069] S2: Fix the on-site calibration tool 4 on the basic rail or wing rail; the on-site calibration tool 4 includes a hook head assembly and a calibration plate 4-1; the hook head assembly is clamped to the basic rail or wing rail, and the calibration plate 4-1 is located on the other side of the basic rail or wing rail; there are at least two calibration points on the calibration plate 4-1, and the connection direction of the calibration points is parallel to the extension direction of the basic rail or wing rail.

[0070] S3: Retract the sliding rod 3 in the detection device 1 to the extreme position, power on the detection device 1, and work the two sensors. Extend the sliding rod 3 so that the ends of the sliding rod 3 are connected to the two calibration points respectively. The two sensors respectively obtain the displacement of the end of the sliding rod 3 from the extreme position to the two calibration points, as well as the two angles measured by the angle sensor.

[0071] S4: Construct a rectangular coordinate system with the axis of the angle sensor as the coordinate origin, and the directions parallel to the basic rail or wing rail and perpendicular to the basic rail or wing rail as the coordinate axes. According to the displacement of the end of the sliding rod 3 from the extreme position to the two calibration points, and the two angles, obtain the distance from the end of the sliding rod 3 to the coordinate origin and the angle between the zero angle of the angle sensor and the coordinate axis when the sliding rod 3 is in the extreme position as calibration parameters to complete the calibration.

[0072] S5: Remove the on-site calibration tooling, connect the end of the sliding rod 3 to the measured point rail or center rail, and calculate the real-time coordinates of the end of the sliding rod 3 in the established rectangular coordinate system. The change in the coordinate value of the real-time coordinate is the change in the position of the measured point rail or center rail.

[0073] When calibrating directly on site, an on-site calibration tool 4 is used. The structural diagram of the on-site calibration tool is shown in Figure 3. The on-site calibration tool 4 includes a hook head assembly and a calibration plate 4-1. The hook head assembly includes a calibration hook head 4-2, a hook head bolt 4-3 and a nut 4-4. When in use, the hook head 4-1 and the hook head portion of the hook head bolt 4-3 are respectively pressed against the two sides and the rail bottom of the base rail or wing rail, the bolt portion of the hook head bolt 4-3 passes through the calibration hook head 4-2, and the end of the bolt portion of the hook head bolt 4-3 is fixed to the calibration hook head 4-2 by the nut 4-4. The calibration plate 4-1 is an L-shaped component. One side of the calibration plate 4-1 is detachably fixed to the calibration hook head 4-2, and the other side is provided with calibration points, and the connection direction of the calibration points is parallel to the extension direction of the base rail or wing rail. A fixing plate is provided on one side of the calibration plate 4-1, and a fixing hole for fixing the detection device 1 is provided on the fixing plate.

[0074] As shown in Figure 4, the mounting bracket 2 includes a mounting hook head 2-1 and a mounting hook head bolt 2-2; when in use, the mounting hook head 2-1 and the hook head parts of the mounting hook head bolt 2-2 are respectively close to the two sides and the rail bottom of the basic rail or the wing rail, the bolt part of the mounting hook head bolt 2-2 passes through the mounting hook head 2-1, and the end of the bolt part of the mounting hook head bolt 2-2 is fixed to the mounting hook head 2-1 by a nut; a mounting plate extends outward from the mounting hook head 2-1; a mounting hole for fixing the detection device 1 is provided on the mounting plate.

[0075] To reduce the workload and working hours under harsh conditions on site, the calibration work can be carried out at the manufacturing plant and the calibration status can be restored at the installation site. The following steps are included:

[0076] S1: The detection device 1 and mounting bracket 2 have interlocking anti-rotation structures, allowing them to be installed only in a fixed relative position. The manufacturing plant calibration fixture has the same anti-rotation structure as the mounting bracket and the fixed mounting structure of the detection device 1. It also has at least two calibration points. Using the detection device 1 as a reference, the connection between these points is parallel to the direction of extension of the base rail or wing rail at the intended application site. The assembled anti-rotation structure 1-1 on the detection device base and the anti-rotation structure 5-1 on the manufacturing plant calibration fixture are shown in Figure 6.

[0077] S2: Fix the detection device 1 on the calibration tool 4 of the manufacturing plant, retract the sliding rod 3 in the detection device 1 to the extreme position, power on the detection device 1, and work the two sensors to extend the sliding rod 3 so that the ends of the sliding rod 3 are respectively connected to the two calibration points. The two sensors respectively obtain the displacement of the end of the sliding rod 3 from the extreme position to the two calibration points, as well as the two angles measured by the angle sensor.

[0078] S3: Construct a rectangular coordinate system with the axis of the angle sensor as the coordinate origin and the directions parallel to the basic rail or wing rail and perpendicular to the basic rail or wing rail as coordinate axes. According to the displacement of the end of the sliding rod 3 from the extreme position to the two calibration points, and the two angles, obtain the distance from the end of the sliding rod 3 to the coordinate origin and the angle between the zero angle of the angle sensor and the coordinate axis when the sliding rod 3 is in the extreme position as calibration parameters to complete the calibration.

[0079] S4: Remove the detection device 1 from the calibration tool 4 in the manufacturing plant, and fix it on the mounting bracket 2 at the installation application site. Retract the sliding rod 3 in the detection device 1 to the extreme position, power on the detection device 1, and work with the two sensors. Connect the end of the sliding rod 3 to the point rail or heart rail to be measured, and calculate the real-time coordinates of the center hole of the sliding rod joint in the established rectangular coordinate system. The change in the coordinate value of the real-time coordinate is the change in the position of the point rail or heart rail to be measured.

[0080] Specifically, an anti-rotation slot is provided on the mounting base of the detection device 1, an anti-rotation socket corresponding to the anti-rotation slot is designed on the calibration tooling of the manufacturing plant, and an anti-rotation socket corresponding to the anti-rotation slot of the detection device 1 is also provided on the mounting bracket. After the anti-rotation slot is inserted into the anti-rotation socket, the shell of the detection device 1 cannot rotate. 5 and 6 , there are at least two calibration points and a fixing hole for the detection device 1 on the calibration tooling of the manufacturing plant, and the connection line of the calibration points and the anti-rotation bayonet have a fixed angle (such as vertical or parallel). After the anti-rotation slot of the detection device 1 is clamped with the anti-rotation bayonet of the calibration tooling of the manufacturing plant, the detection device 1 is fixed to the calibration tooling of the manufacturing plant using the fastening hole so that it cannot move relative to it, and the sliding rod of the detection device 1 is respectively connected to the calibration points of an appropriate number and position. The detection device 1 is powered on and works when the sliding rod is retracted to the extreme position, and the calibration parameters are calculated according to the sensor values ​​of the detection device 1 to obtain the calibration parameters of the angle sensor and the calibration parameters of the linear displacement sensor. After calibration, the detection device 1 can be installed and operated on site. After the mounting bracket 2 is fixed to the base rail or wing rail, the anti-rotation slot of the detection device 1 is clamped with the anti-rotation bayonet of the mounting bracket 2 and the detection device 1 is fixed to the mounting bracket 2. Then, for the angle sensor, the angle of the detection device 1 relative to the coordinate axis when it is installed on the calibration tool 4 in the manufacturing plant and on the mounting bracket 2 is the same or the deviation is a preset fixed value. Retract the sliding rod 3 to the extreme position or use a limit sleeve to limit the extreme position, then power on the detection device 1 to start working, connect the sliding rod 3 to the object to be measured, and the coordinate value of the object to be measured in the constructed coordinate system can be measured in real time. The schematic diagram of the mounting bracket of the anti-rotation bayonet is shown in Figure 9.

[0081] The manufacturing plant calibration tooling has a fixed installation structure for the detection device 1, and has a bayonet that matches the slot on the detection device 1. The detection device 1 slot is fixed with the bayonet after being matched with the bayonet. At least two calibration points are set on the manufacturing plant calibration tooling. The angle between the connection line of the calibration points and the specified part of the detection device 1 is the same as the angle between the specified part and the extension direction of the base rail or wing rail after the detection device 1 is fixedly installed on the mounting bracket, or the deviation is a preset fixed value. The calibration point is usually a hole with a fixed diameter, which is connected with the center hole of the sliding rod joint of the detection device using a connecting pin. The detection device 1 outputs the sensor detection value corresponding to the calibration point. According to the calibration algorithm, the calibration parameters can be calculated using appropriate calibration points.

[0082] Specifically, the relationship between the calibration parameters in S3 and S4 and the sensor measured values ​​is shown in FIG2 . The calculation process of the calibration parameters includes the following steps:

[0083] Construct a coordinate system with the basic rail or wing rail direction as the X-axis, the detection device rotation center as the coordinate origin, and the direction perpendicular to the basic rail or wing rail as the Y-axis. The direction of the line connecting the two calibration points is parallel to the coordinate axis X-axis. Then the Y coordinates of the two calibration points are equal in the calibrated coordinate system, and the difference in X coordinates is equal to the distance between the two calibration points; the detection device rotation center is set to O, and the distance from the detection device rotation center O to the center hole of the sliding rod joint is R when the sliding rod is in the retracted limit position. The calibration points are A and B, and the distance is m. When the center hole of the sliding rod joint moves to A and B, the displacement relative to the retracted limit position is L1 and L2 respectively. The angle values ​​measured by the angle sensor are α1 and α2 respectively. Then, if the angle zero position of the angle sensor is OP and is located between the X-axis and OB, then ∠POA=α1, ∠POB=α1, and the angle between the angle zero position of the angle sensor and the basic rail or wing rail direction is the angle β between OP and the X-axis;

[0084] According to the law of sine: (L1+R) / sin(β+α2)=m / sin(α1-α2)=(L2+R) / sin(180°-(β+α1))

[0085] That is: m*sin(β+α2)=(L1+R)*sin(α1-α2) m*sin(180°-(β+α1))=(L2+R)*sin(α1-α2)

[0086] According to the projection relationship of OA and OB on the X-axis and Y-axis, (L2+R)*sin(β+α2)=(L1+R)*sin(β+α1) (L2+R)*cos(β+α2)=m+(L1+R)*cos(β+α1)

[0087] In addition, there are: sin(β + α2) = sinβcos(α2) + cosβsin(α2); sin(β + α1) = sinβcos(α1) + cosβsin(α1); cos(β + α2) = cosβcos(α2) - sinβsin(α2); cos(β + α1) = cosβcos(α1) - sinβsin(α1).

[0088] Then: m*sin(180° - (β + α1)) = (L2 + R)*sin(α1 - α2); m*sin(β + α2) = (L1 + R)*sin(α1 - α2).

[0089] Subtracting the two sides of the equal sign respectively gives: m*(sin(β + α1) - sin(β + α2)) = (L2 - L1)*sin(α1 - α2).

[0090] Then: m*(2cos((2*β + α1 + α2) / 2)sin((α1 - α2) / 2)) = (L2 - L1)*sin(α1 - α2); cos((2*β + α1 + α2) / 2) = (L2 - L1)*sin(α1 - α2) / (2*m*sin((α1 - α2) / 2)).

[0091] Then: β + (α1 + α2) / 2 = 2kπ ± arccos((L2 - L1)*sin(α1 - α2)) / (2*m*sin((α1 - α2) / 2))).

[0092] Then, the calculation formula for the included angle β between the zero position of the angle of the angle sensor and the direction of the stock rail or wing rail is: β = 2kπ ± arccos((L2 - L1)*sin(α1 - α2) / (2*m*sin((α1 - α2) / 2))) - (α1 + α2) / 2

[0093] where, 0° ≤ β ≤ 90°;

[0094] Obtain the calculation formula for R according to m*sin(β + α2) = (L1 + R)*sin(α1 - α2) or m*sin(180° - (β + α1)) = (L2 + R)*sin(α1 - α2).

[0095] If the OP position does not match Figure 2, the angle sensor can be rotated to the zero position shown in Figure 2. There are at least three rotation methods. The first is to physically rotate the relevant parts. The second is to implement this through the function of the angle sensor, which is equivalent to physical implementation. The third is to subtract the angle value to be rotated from the output angle of the angle sensor. If the zero position of the angle cannot be maintained after the sensor is powered off and then powered on again, the angle of the zero position must be recorded in the software and used as a calculation parameter together with β in subsequent calculations.

[0096] Example 2

[0097] The relationship between the calibration parameters in S3 and S4 and the values ​​measured by the sensors is shown in FIG2 . The relationship between the angle between the zero position of the angle sensor and the direction of the base rail or wing rail and the distance from the rotation center of the detection device to the extreme position is constructed, including the following steps:

[0098] Construct a coordinate system with the base rail or wing rail direction as the X-axis, the rotation center of the detection device as the coordinate origin, and the Y-axis perpendicular to the base rail or wing rail. The Y coordinates of the two calibration points are equal in the calibrated coordinate system, and the difference in X coordinates is equal to the distance between the two calibration points.

[0099] The rotation center of the detection device is set to O. The distance from the rotation center O of the detection device to the center hole of the sliding rod joint when the sliding rod is at the retracted limit position is R. The calibration points are A and B, and the distance is m. When the center hole of the sliding rod joint moves to A and B, the displacement relative to the retracted limit is L1 and L2 respectively. The angle values ​​measured by the angle sensor are α1 and α2 respectively. Then, if the angle zero position of the angle sensor is OP and is located between the X-axis and OB, then ∠POA=α1, ∠POB=α1, and the angle between the angle zero position of the angle sensor and the direction of the base rail or wing rail is the angle β between OP and the X-axis;

[0100] Construct a circle with OA as its diameter and determine that the point of intersection of this circle and OB is C; in triangle ABC, ∠BAC = ∠a, ∠ACB = ∠c, and ∠ABC = ∠b;

[0101] Using the law of sines:

[0102] Then, the three internal angles in the triangle are: ∠b=α2+β

[0103] Substituting into the sine formula we get:

[0104] According to the trigonometric function formula sin(90°+α)=cosα, sin(90°-α)=cosα, the formula changes to:

[0105] Where, 0°≤β≤90°; the calculation formula for the angle β between the zero position of the angle sensor and the direction of the base rail or wing rail is obtained from the above formula;

[0106] The calculation formula for R is obtained according to m*sin(β+α2)=(L1+R)*sin(α1-α2) or m*sin(180°-(β+α1))=(L2+R)*sin(α1-α2).

[0107] Example 3

[0108] When the OP position does not match Figure 2, calibration calculations can be performed according to Figure 7 or Figure 8 or other situations, but the principles are basically the same. The angle of the sliding rod measured by the angle sensor is used to express the angle relationship between the sliding rod and the positive direction of the X-axis, and the displacement value of the sliding rod is used to express the distance from the coordinate center to the center of the sliding rod joint. Then, the coordinate value of the center of the sliding rod joint is calculated in a predetermined coordinate system (rectangular coordinate system or polar coordinate system).

[0109] For a detection device with the CN202310779837.X structure, the position of the center hole of the sliding rod joint can be calculated using polar coordinates and converted into rectangular coordinates in the corresponding rectangular coordinate system, which is the position of the measured part connected to the center hole of the sliding rod joint.

[0110] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A calibration method for an orthogonal motion detection device, characterized in that, Including the following steps: Calibrating a detection device that performs orthogonal motion based on an application site or a manufacturing plant; wherein, when calibrating at the application site, the detection device is fixedly installed at the application site using a mounting bracket, and a on-site calibration tooling is used for calibration; when calibrating at the manufacturing plant, a manufacturing plant calibration tooling with an anti-rotation structure is used to fix the detection device and perform calibration; Taking the intersection point of the detection axis of the angular sensor in the detection device and the detection plane as the coordinate origin, and taking the concerned motion direction as the coordinate axis direction to form a rectangular coordinate system; both the on-site calibration tooling and the manufacturing plant calibration tooling include at least two calibration point positions, and the connecting line direction of the calibration point positions is parallel or perpendicular to the coordinate axis or has a preset numerical angle; Retracting the sliding rod in the detection device to the limit position, powering on the detection device, and operating two sensors. Extend the sliding rod so that the central holes of the sliding rod joints are respectively connected to the two calibration point positions. Obtain the displacements of the central holes of the sliding rod joints from the limit position to the two calibration point positions through the two sensors respectively, and the two rotation angles measured by the angular sensor; According to the calibration algorithm, calculate the distance from the central hole of the sliding rod joint to the coordinate origin and the angle between the zero angle of the angular sensor and the coordinate axis when the sliding rod is at the limit position, and use them as calibration parameters to complete the calibration; When calibrating at the application site, remove the on-site calibration tooling, connect the central hole of the sliding rod joint to the object to be measured, and calculate the real-time coordinates of the central hole of the sliding rod joint in the established rectangular coordinate system based on the calibration parameters. The change in the coordinate values of the real-time coordinates is the change in the position of the object to be measured; when calibrating at the manufacturing plant, remove the detection device from the manufacturing plant calibration tooling, install the detection device on the application site through a mounting bracket with the same anti-rotation structure, connect the central hole of the sliding rod joint to the object to be measured, and perform position change measurement.

2. The calibration method of the orthogonal motion detection device according to claim 1, characterized in that, The object to be measured is the switch rail or the stock rail of a turnout; When calibrating at the application site, fixedly install the detection device on the outside of the stock rail or wing rail through a mounting bracket. The on-site calibration tooling is installed and fixed on the stock rail or wing rail during the calibration process to perform on-site calibration; after calibration, remove the on-site calibration tooling, connect the central hole of the sliding rod joint to the switch rail or stock rail to be measured, and determine the displacement of the stock rail or switch rail to be measured according to the calibration parameters; When calibrating at the manufacturing plant, use a manufacturing plant calibration tooling with an anti-rotation structure to fix the detection device and perform calibration; after calibration, install the detection device on the stock rail or wing rail through a mounting bracket with the same anti-rotation structure, connect the central hole of the sliding rod joint to the switch rail or stock rail to be measured, and perform position change measurement.

3. The calibration method of the orthogonal motion detection device according to claim 2, characterized in that, The step of calculating the distance from the central hole of the sliding rod joint to the coordinate origin and the angle between the zero angle of the angular sensor and the coordinate axis when the sliding rod is at the limit position according to the calibration algorithm includes the following steps: Construct a coordinate system with the direction of the stock rail or wing rail as the X axis, the rotation center of the detection device as the coordinate origin, and the direction perpendicular to the stock rail or wing rail as the Y axis. The connecting line direction of the two calibration point positions is parallel to the coordinate axis X, then the Y coordinates of the two calibration point positions in the calibrated coordinate system to be solved are equal, and the difference in the X coordinates is equal to the distance between the two calibration point positions; Set the rotation center of the detection device as O. The distance from the rotation center O of the detection device to the center hole of the sliding rod joint is R when the sliding rod is in the retracted limit position. The calibration points are A and B respectively, and the distance between them is m. When the center hole of the sliding rod joint moves to A and B, the displacements relative to the retracted limit position are L1 and L2 respectively. The rotation angle values measured by the rotation angle sensor are α1 and α2 respectively. Then, if the zero angle position of the rotation angle sensor is OP and is between the X-axis and OB, then ∠POA = α1, ∠POB = α1, and the included angle between the zero angle position of the rotation angle sensor and the direction of the basic rail or wing rail is the included angle β between OP and the X-axis; According to the sine theorem: (L1 + R) / sin(β + α2) = m / sin(α1 - α2) = (L2 + R) / sin(180° - (β + α1)) That is: m * sin(β + α2) = (L1 + R) * sin(α1 - α2) m * sin(180° - (β + α1)) = (L2 + R) * sin(α1 - α2) According to the projection relationship of OA and OB on the X-axis and Y-axis, then: (L2 + R) * sin(β + α2) = (L1 + R) * sin(β + α1) (L2 + R) * cos(β + α2) = m + (L1 + R) * cos(β + α1) In addition: sin(β + α2) = sinβcos(α2) + cosβsin(α2) sin(β + α1) = sinβcos(α1) + cosβsin(α1) cos(β + α2) = cosβcos(α2) - sinβsin(α2) cos(β + α1) = cosβcos(α1) - sinβsin(α1) Then: m * sin(180° - (β + α1)) = (L2 + R) * sin(α1 - α2) m * sin(β + α2) = (L1 + R) * sin(α1 - α2) Subtract the two sides of the equal sign respectively to get: m * (sin(β + α1) - sin(β + α2)) = (L2 - L1) * sin(α1 - α2) Then: m * (2cos((2 * β + α1 + α2) / 2)sin((α1 - α2) / 2) = (L2 - L1) * sin(α1 - α2) cos((2 * β + α1 + α2) / 2) = (L2 - L1) * sin(α1 - α2) / (2 * m * sin((α1 - α2) / 2)) Then: β + (α1 + α2) / 2 = 2kπ ± arccos((L2 - L1) * sin(α1 - α2)) / (2 * m * sin((α1 - α2) / 2))) Then, the calculation formula for the included angle β between the zero angle position of the rotation angle sensor and the direction of the basic rail or wing rail is: β = 2kπ ± arccos((L2 - L1) * sin(α1 - α2) / (2 * m * sin((α1 - α2) / 2))) - (α1 + α2) / 2 Where, 0° ≤ β ≤ 90°; The calculation formula of R is obtained according to m*sin(β + α2) = (L1 + R)*sin(α1 - α2) or m*sin(180° - (β + α1)) = (L2 + R)*sin(α1 - α2).

4. The calibration method of the orthogonal motion detection device according to claim 2, characterized in that According to the calibration algorithm, when calculating the sliding rod at the limit position, the distance from the center hole of the sliding rod joint to the coordinate origin and the included angle between the zero angle of the rotation angle sensor and the coordinate axis include the following steps: Construct a coordinate system with the direction of the basic rail or wing rail as the X-axis, the rotation center of the detection device as the coordinate origin, and the direction perpendicular to the basic rail or wing rail as the Y-axis. The Y coordinates of the two calibration points are equal in the calibrated coordinate system to be solved, and the difference in the X coordinates is equal to the distance between the two calibration points; Let the rotation center of the detection device be O. The distance from the rotation center O of the detection device to the center hole of the sliding rod joint is R when the sliding rod is in the retracted limit position. The calibration points are A and B respectively, and the distance is m. When the center hole of the sliding rod joint moves to A and B, the displacements relative to the retracted limit are L1 and L2 respectively, and the rotation angle values measured by the rotation angle sensor are α1 and α2 respectively. Then, if the zero angle position of the rotation angle sensor is OP and is between the X-axis and OB, then ∠POA = α1, ∠POB = α1, and the included angle between the zero angle position of the rotation angle sensor and the direction of the basic rail or wing rail is the included angle β between OP and the X-axis; Construct a circle with OA as the diameter, and determine that the intersection point of this circle and OB is C; in triangle ABC, ∠BAC = ∠a, ∠ACB = ∠c, and ∠ABC = ∠b; Using the sine theorem, we have: Then, the three interior angles in the triangle are: ∠b＝α2+β Substituting into the sine formula gives: From the trigonometric function transformation formula sin(90° + α) = cosα, sin(90° - α) = cosα, the formula is transformed into: Among them, 0° ≤ β ≤ 90°; the calculation formula of the included angle β between the zero angle position of the rotation angle sensor and the direction of the basic rail or wing rail is obtained from the above formula; The calculation formula of R is obtained according to m*sin(β + α2) = (L1 + R)*sin(α1 - α2) or m*sin(180° - (β + α1)) = (L2 + R)*sin(α1 - α2).

5. The calibration method of the orthogonal motion detection device according to claim 3 or 4, characterized in that If the zero angle position OP of the rotation angle sensor is not between the X-axis and OB, then rotate the zero angle position of the rotation angle sensor to meet the requirements through physical angle rotation or numerical compensation; among them, the numerical compensation method is to subtract the angle value that needs to be rotated from the output angle of the rotation angle sensor. When the rotation angle sensor is powered off and then powered on again, if the rotated zero angle position cannot be maintained, the rotation angle of the zero angle position needs to be recorded in the software, and it needs to be used as a calculation parameter together with the included angle β between the zero angle position of the rotation angle sensor and the direction of the basic rail or wing rail in subsequent calculations.

6. The calibration method of the orthogonal motion detection device according to claim 2, characterized in that, The on-site calibration tooling is installed and fixed on the stock rail or wing rail during the calibration process; the on-site calibration tooling includes a hook head assembly and a calibration plate; the hook head assembly is clamped to the stock rail or wing rail, and the calibration plate is located on the other side of the stock rail or wing rail; the hook head assembly includes a calibration hook head, a hook head bolt and a nut; during use, the hook head part of the calibration hook head and the hook head bolt respectively abut against both sides and the bottom of the stock rail or wing rail, the bolt part of the hook head bolt passes through the calibration hook head, and the end of the bolt part of the hook head bolt is fixed to the calibration hook head through the nut; the calibration plate is an L-shaped or T-shaped member; one side of the calibration plate is detachably fixed to the calibration hook head, the other side is provided with calibration points, and the connecting line direction of the calibration points is parallel to the extending direction of the stock rail or wing rail.

7. The calibration method of the orthogonal motion detection device according to claim 2, characterized in that, The base of the detection device is provided with an anti-rotation structure, which cooperates with the mounting bracket to prevent the detection device from rotating relative to the mounting bracket, including an anti-rotation card slot or a positioning pin; the manufacturing plant calibration tooling is provided with an anti-rotation structure matching the detection device.

8. The calibration method of the orthogonal motion detection device according to claim 7, characterized in that, The mounting bracket includes a mounting hook head and a mounting hook head bolt; during use, the hook head part of the mounting hook head and the mounting hook head bolt respectively abut against both sides and the bottom of the stock rail or wing rail, the bolt part of the mounting hook head bolt passes through the mounting hook head, and the end of the bolt part of the mounting hook head bolt is fixed to the mounting hook head through a nut; the mounting hook head extends outwards with a mounting plate; the mounting plate is provided with mounting holes for fixing the detection device.

9. The calibration method of the orthogonal motion detection device according to claim 1, characterized in that, The calibration tooling includes a limit sleeve, which is used to limit the limit position of the sliding rod retracting. When the sliding rod needs to retract to the limit position during the calibration process and the on-site restoration process, the limit sleeve is clamped on the outer periphery of the sliding rod, and the limit sleeve is removed after completion.

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