Beidou-vision fusion box girder hoisting monitoring method and system and risk assessment method

Abstract

The invention provides a Beidou-vision fusion box girder hoisting monitoring method and system and a risk assessment method, and belongs to the technical field of suspension bridge construction. The hoisting monitoring method comprises the following steps: performing time calibration on position data acquired by a Beidou positioning system and image data acquired by image acquisition equipment to form calibrated position data and calibrated image data; respectively calculating a first central position coordinate under the Beidou positioning system and a second spatial position coordinate under the image acquisition equipment according to the calibration position data and the calibration image data; according to the weight of the first central position, the weight of the second spatial position, the coordinates of the first central position and the coordinates of the second spatial position, position data acquired by the Beidou positioning system and image data acquired by the image acquisition device are fused; therefore, mutual coupling of the position data acquired by the Beidou positioning system and the image data acquired by the image acquisition equipment is realized, and the adjustment precision of the standard section of the box girder is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of suspension bridge construction, and relates to a box girder hoisting technology in suspension bridge construction, in particular to a Beidou-vision fusion box girder hoisting monitoring method and system and a risk assessment method. BACKGROUND

[0002] Suspension bridge is one of the landmark achievements of modern long-span bridge engineering. Among them, the bridge deck of the suspension bridge is paved by the box girder, and the box girder is used to bear the vehicle load acting on the bridge deck and transmit the vehicle load to the main cable through the sling, and the vehicle load is transmitted to the main cable saddle above the main cable tower through the main cable, and then transmitted to the main cable tower through the main cable saddle, and finally transmitted to the ground through the main cable tower.

[0003] In the construction of long-span suspension bridges, the hoisting of the box girder is a crucial link in the construction of the superstructure of the suspension bridge. It is to hoist the box girder standard segment pre-installed in the factory on site by large hoisting equipment. In the process of hoisting the box girder standard segment, the attitude of the box girder standard segment will directly affect the linear smoothness and structural safety of the main girder body. For example, if the attitude deviation of the box girder standard segment exceeds the standard, it is easy to cause the stress concentration of the sling, the local stress of the main girder body exceeds the limit, and the hoisting accident is caused.

[0004] At present, there are many technologies for monitoring in the process of hoisting the box girder standard segment, such as GPS positioning technology for monitoring the hoisting height, angle sensor for monitoring the hoisting attitude, and force sensor for monitoring the lifting force of the sling. Through monitoring, not only can the hoisting and splicing deviation of the box girder standard segment be reduced, but also the safety risks existing in the construction can be found in time according to the monitoring data. In the prior art, the adjustment scheme for the box girder standard segment in the hoisting process is often determined according to a single data, for example, the hoisting height of the box girder standard segment is monitored by GPS positioning technology, the attitude of the box girder standard segment is monitored by image acquisition equipment, and the box girder standard segment is adjusted according to the two monitoring results. In fact, the hoisting of the box girder standard segment is a coupling effect under multiple conditions. The isolated adjustment by a single data not only causes contradictions between the adjustment schemes due to the different standards of different measurement methods, but also affects the accuracy of the adjustment of the box girder standard segment in the hoisting process. SUMMARY

[0005] In view of the above background technology, the prior art for adjusting the box girder standard segment in the hoisting process often only considers a single data without considering the mutual coupling between the data, which not only causes contradictions between the adjustment schemes due to the different standards of different measurement methods, but also affects the accuracy of the adjustment of the box girder standard segment in the hoisting process. In view of these technical problems, the present application provides a Beidou-vision fusion box girder hoisting monitoring method and system and a risk assessment method.

[0006] The application solves the technical problems of the prior art that only considering single data may cause contradictions between the adjustment schemes and affect the adjustment accuracy of the box girder standard segment.

[0007] To solve the above technical problems, the application adopts the following technical scheme: The Beidou-vision fusion box girder hoisting monitoring method comprises the following steps: S1: arranging a Beidou positioning system and a marker point on the box girder standard segment and arranging an image acquisition device on the hoisting equipment; S2: before hoisting the box girder standard segment, performing initial calibration on the box girder standard segment by the position data collected by the Beidou positioning system; S3: during the hoisting process of the box girder standard segment, collecting the position data of the box girder standard segment by the Beidou positioning system and collecting the image data of the marker point on the box girder standard segment by the image acquisition device; Time calibration is performed on the position data collected by the Beidou positioning system and the image data collected by the image acquisition device to obtain calibrated position data and calibrated image data; The first central position coordinates of the box girder standard segment under the Beidou positioning system are determined according to the calibrated position data, and the second spatial position coordinates of the box girder standard segment under the image acquisition device are determined according to the calibrated image data; S4: calculating the weight of the first central position and the weight of the second spatial position, and calculating the fusion position coordinates according to the weight of the first central position, the first central position coordinates, the weight of the second spatial position and the second spatial position coordinates; S5: adjusting the box girder standard segment during the hoisting process of the box girder standard segment according to the fusion position coordinates.

[0008] Further limited, the Beidou positioning system comprises a Beidou positioning terminal and a Beidou positioning base station, and the step S1 is specifically: One Beidou positioning terminal is arranged at each of the four corner points of the box girder standard segment, and a Beidou positioning base station is arranged on the working plane of the box girder that has been hoisted; Marker points are arranged at the four corner points of the box girder standard segment, and the positions of the marker points do not coincide with the positions of the Beidou positioning terminals; The image acquisition device is arranged at the top point of each sling, and the position of the image acquisition device corresponds to the position of the marker point, and the image acquisition device is used to collect the image data of the corresponding marker point.

[0009] Further limited, the step S2 is specifically: Before hoisting the box girder standard segment, horizontal position data of each corner point of the box girder standard segment is collected by a Beidou positioning terminal, horizontal position data of a working plane of the box girder is collected by a Beidou positioning base station, and the horizontal position data of each corner point of the box girder standard segment is calibrated based on the horizontal position data of the working plane of the box girder.

[0010] With further limitation, the time calibration of the position data collected by the Beidou positioning system and the image data collected by the image acquisition device in the step S3 specifically includes: Taking two adjacent time points t i and t i+1 when collecting the position data by the Beidou positioning system as the reference, the image data collected by the image acquisition device is determined by using the following formula: In the formula, I is the image data collected by the image acquisition device at the time t, unit: pixel; is the image data collected by the image acquisition device at the time t , unit: pixel; is the image data collected by the image acquisition device at the time (i+1), unit: pixel; t i and t i+1 are two adjacent time points when collecting the position data by the Beidou positioning system, unit: second.

[0011] With further limitation, the determination process of the first central position coordinates and the second spatial position coordinates in the step S3 is as follows: The coordinates of the central position of the box girder standard segment are calculated according to the calibrated position data, which are taken as the first central position coordinates (X BD , Y BD , Z BD ); The extrinsic matrix T of the image acquisition device is obtained, and the second spatial position coordinates (X vis , Y vis , Z vis ) are determined according to the calibrated image data (u, v, p) by using the following formula: In the formula, u is the pixel of the mark point in the X direction in the calibrated image data, unit: piece; v is the pixel of the mark point in the Y direction in the calibrated image data, unit: piece; p is the pixel of the mark point in the Z direction in the calibrated image data, unit: piece; and T is the extrinsic matrix of the image acquisition device, dimensionless.

[0012] Further, in the step S4, the weight of the first center position includes a first horizontal center position weight ω1 and a first vertical center position weight ω3; and the weight of the second spatial position includes a second horizontal spatial position weight ω2 and a second vertical spatial position weight ω4. The first horizontal center position weight ω1 and the second horizontal spatial position weight ω2 are determined according to a first horizontal confidence C SBD and a second horizontal confidence C Svis . The first horizontal confidence C SBD is determined according to the standard deviation of (X BD , Y BD ) in the first center position coordinates, and the second horizontal confidence C Svis is determined according to the standard deviation of (X vis , Y vis ) in the second spatial position coordinates. The first vertical center position weight ω3 and the second vertical spatial position weight ω4 are determined according to a first vertical confidence C ZBD and a second vertical confidence C Zvis . The first vertical confidence C ZBD is determined according to the standard deviation of Z BD in the first center position coordinates, and the second vertical confidence C Zvis is determined according to the standard deviation of Z vis in the second spatial position coordinates.

[0013] Further, in the step S4, the fused position coordinates (X R , Y R , Z R ) calculated according to the weight of the first center position, the first center position coordinates, the weight of the second spatial position and the second spatial position coordinates are: X R = ω1 × X BD + ω2 × X vis Y R = ω1 × Y BD + ω2 × Y vis Z R = ω3 × Z BD + ω4 × Z vis wherein ω1 is the first horizontal center position weight, dimensionless; ω2 is the second horizontal spatial position weight, dimensionless; ω3 is the first vertical center position weight, dimensionless; ω4 is the second vertical spatial position weight, dimensionless; X BD , Y BD , Z BDX, Y, Z respectively are the values of the first center position coordinates in X direction, Y direction and Z direction, unit: meter; X vis , Y vis , Z vis X, Y, Z respectively are the values of the second spatial position coordinates in X direction, Y direction and Z direction, unit: meter. R , Y R , Z R X, Y, Z respectively are the values of the fusion position coordinates in X direction, Y direction and Z direction, unit: meter.

[0014] The Beidou-vision fusion box girder hoisting monitoring system formed based on the above Beidou-vision fusion box girder hoisting monitoring method, comprising: A calibration module: used for initial calibration of the box girder standard segment before hoisting, by position data collected by the Beidou positioning system and image data of the marker points collected by the image acquisition device, wherein the Beidou positioning system and the marker points are arranged on the box girder standard segment, and the image acquisition device is arranged on the hoisting device; A data acquisition and processing module: used for collecting position data of the box girder standard segment by the Beidou positioning system and collecting image data of the marker points on the box girder standard segment by the image acquisition device during the hoisting process of the box girder standard segment; time calibration is performed on the position data collected by the Beidou positioning system and the image data collected by the image acquisition device to obtain calibrated position data and calibrated image data; the first center position coordinates of the box girder standard segment under the Beidou positioning system are determined according to the calibrated position data, and the second spatial position coordinates of the box girder standard segment under the image acquisition device are determined according to the calibrated image data; A fusion calculation module: used for calculating the weight of the first center position and the weight of the second spatial position, and calculating the fusion position coordinates according to the weight of the first center position, the first center position coordinates, the weight of the second spatial position and the second spatial position coordinates; And an adjusting module: used for adjusting the box girder standard segment during the hoisting process of the box girder standard segment according to the fusion position coordinates.

[0015] The Beidou-vision fusion box girder hoisting risk assessment method comprises the following steps: Angle sensors are arranged in the X direction and the Y direction of the box girder standard segment respectively; a force sensor is arranged at the top of the sling; the angle of the box girder standard segment in the X direction is monitored according to the angle sensor in the X direction, and the angle of the box girder standard segment in the Y direction is monitored according to the angle sensor in the Y direction; the tension of the sling is monitored according to the force sensor; The risk monitoring target function of the box girder standard segment is established based on the angle of the box girder standard segment in the X direction, the angle of the box girder standard segment in the Y direction, the tension of the sling and the first central position coordinate and the second spatial position coordinate in the above-mentioned Beidou-vision fusion box girder hoisting monitoring method, and the target monitoring value is determined based on the risk monitoring target function; wherein the risk monitoring target function of the box girder standard segment is: In the formula, The target monitoring value, unit: meter; The risk weight component of the box girder standard segment in the horizontal direction, dimensionless; The position deviation of the box girder standard segment in the X direction, unit: meter, The position deviation of the box girder standard segment in the Y direction, unit: meter, The risk weight component of the box girder standard segment in the vertical direction, dimensionless; The elevation deviation of the box girder standard segment, unit: meter, The angle deviation of the box girder standard segment in the X direction, unit: °; The angle deviation of the box girder standard segment in the Y direction, unit: °; L1 is the width of the box girder standard segment, unit: meter; L2 is the length of the box girder standard segment, unit: meter; The tension risk weight component of the sling, dimensionless; The tension deviation of the sling, unit: KN; K is the stiffness of the sling, unit: kN / m; The target monitoring value is normalized to obtain a risk prediction index E; and the risk in the hoisting process of the box girder standard segment is evaluated based on the risk prediction index E.

[0016] Further limited, the risk in the hoisting process of the box girder standard segment is evaluated based on the risk prediction index E specifically as follows: If 0.3 >= E > 0, the attitude deviation of the box girder standard segment is small, and there is no hoisting risk; If 0.7 >= E > 0.3, the attitude deviation of the box girder standard segment is within the allowable deviation, and the hoisting risk is in the key observation stage; If E > 0.7, the attitude deviation of the box girder standard segment exceeds the allowable deviation, and there is a hoisting risk.

[0017] Compared with the prior art, the beneficial effects of the present application are as follows: ​​​1. The Beidou-vision fusion box girder hoisting monitoring method of the application, when hoisting the box girder standard segment, time calibrates the position data collected by the Beidou positioning system and the image data collected by the image acquisition device to form calibrated position data and calibrated image data, calculates the first central position coordinates under the Beidou positioning system and the second spatial position coordinates under the image acquisition device according to the calibrated position data and the calibrated image data; then determines the weight of the first central position and the weight of the second spatial position, and fuses the position data collected by the Beidou positioning system and the image data collected by the image acquisition device according to the weight of the first central position, the weight of the second spatial position, the first central position coordinates and the second spatial position coordinates, so as to realize the mutual coupling of the position data collected by the Beidou positioning system and the image data collected by the image acquisition device, solve the technical problems that the existing technology only considers single data and the adjustment schemes appear contradictory, and affect the adjustment accuracy of the box girder standard segment, and improve the adjustment accuracy of the box girder standard segment.

[0018] 2. The Beidou-vision fusion box girder hoisting risk assessment method of the application, which establishes a risk monitoring target function according to the angle deviation monitored by the angle sensor, the tension deviation of the sling monitored by the force sensor, and the first central position coordinates and the second spatial position coordinates, calculates a target monitoring value based on the risk monitoring target function, normalizes the target monitoring value to obtain a risk prediction index, and uses the risk prediction index to predict the risk in the box girder standard segment hoisting process, so as to realize the risk assessment of the Beidou-vision fusion box girder hoisting and improve the safety of the box girder standard segment hoisting. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic diagram of the Beidou-vision fusion box girder hoisting monitoring method of the application; Figure 2 It is a schematic diagram of the Beidou-vision fusion box girder hoisting monitoring system of the application; Figure 3 It is a schematic diagram of the risk assessment method of the application; Figure 4 It is a schematic diagram of the box girder standard segment hoisting and monitoring; Figure 5 It is a distribution schematic diagram of the Beidou positioning terminal, the marker point and the angle sensor on the box girder standard segment; Figure 6 It is a top plane schematic diagram on the box girder standard segment; BRIEF DESCRIPTION OF DRAWINGS 1-box girder standard segment, 2-Beidou positioning terminal, 3-Beidou positioning base station, 4-span cable crane, 5-image acquisition device, 6-marker point, 7-angle sensor, 8-sling. DETAILED DESCRIPTION

[0020] The technical solutions of the present application will be further explained in combination with the drawings and specific embodiments, but the present application is not limited to the following described embodiments.

[0021] Referring to Figure 4 , Figure 5 and Figure 6 , when the box girder standard segment 1 is hoisted, two side-by-side cross-cable cranes 4 are arranged, wherein one end of the two cross-cable cranes 4 is slidably connected with the main cable on one side, and the other end of the two cross-cable cranes 4 is slidably connected with the main cable on the other side, two lifting ropes 8 are arranged on each of the two cross-cable cranes 4, i.e. a total of four lifting ropes 8, the lifting ropes 8 are connected at the lifting points of the box girder standard segment 1, wherein one lifting point is arranged at each of the four corner points of the box girder standard segment 1, i.e. the positions of the four lifting points correspond to the positions of the four lifting ropes 8.

[0022] In the present application, the data acquisition device includes a Beidou positioning system, an image acquisition device 5, an angle sensor 7 and a force sensor, wherein the Beidou positioning system includes a Beidou positioning terminal 2 and a Beidou positioning base station 3, the Beidou positioning terminal 2 has four, which are arranged at the four corner points of the box girder standard segment 1 to be hoisted, and at the same time, a marker point 6 is arranged at the four corner points of the box girder standard segment 1 to be hoisted, the marker point 6 is a solid dot; the angle sensor 7 has two, which are arranged along the X direction and the Y direction of the box girder standard segment 1, preferably, one of the angle sensors 7 is arranged at the middle position of the long side of the box girder standard segment 1 along the X direction of the box girder standard segment 1, i.e. the long side direction of the box girder standard segment 1 is the X direction, and the other angle sensor 7 is arranged at the middle position of the short side of the box girder standard segment 1 along the Y direction of the box girder standard segment 1, i.e. the short side direction of the box girder standard segment 1 is the Y direction. The force sensor has four, which are arranged at the top of the four lifting ropes 8. The image acquisition device 5 has four, which are arranged at the top of the four lifting ropes 8, and the positions of the image acquisition devices 5 correspond to the positions of the marker points 6, i.e. one image acquisition device 5 corresponds to one marker point 6, and the camera of each image acquisition device 5 directly faces the corresponding marker point 6.

[0023] Referring to Figure 1 , the present application proposes a Beidou-vision fusion box girder hoisting monitoring method, which includes the following steps: S1: a Beidou positioning system and a marker point 6 are arranged on the box girder standard segment 1, and an image acquisition device 5 is arranged on the hoisting equipment; specifically, step S1 is that one Beidou positioning terminal 2 is arranged at each of the four corner points of the box girder standard segment 1, and a Beidou positioning base station 3 is arranged on the working plane of the box girder which has been hoisted; a marker point 6 is arranged at each of the four corner points of the box girder standard segment 1, and the position of the marker point 6 does not coincide with the position of the Beidou positioning terminal 2; an image acquisition device 5 is arranged at the top of each sling 8, and the position of the image acquisition device 5 corresponds to the position of the marker point 6, and the image acquisition device 5 is used to acquire image data of the corresponding marker point 6. The Beidou positioning terminal 2 and the Beidou positioning base station 3 both use GNSS technology to acquire position data; the image acquisition device 5 is an industrial camera or other devices capable of image acquisition which are well known to those skilled in the art.

[0024] S2: before hoisting the box girder standard segment 1, the box girder standard segment 1 is initially calibrated by the position data acquired by the Beidou positioning system; specifically, step S2 is that before hoisting the box girder standard segment 1, the horizontal position data of each corner point of the box girder standard segment 1 is acquired by the Beidou positioning terminal 2, and the horizontal position data of the working plane of the box girder is acquired by the Beidou positioning base station 3, and the horizontal position data of each corner point of the box girder standard segment 1 is calibrated based on the horizontal position data of the working plane of the box girder. The Beidou positioning base station 3 is arranged at the center position of the working plane of the box girder, and the data acquired by the Beidou positioning base station 3 is the center position data of the working plane of the box girder. Wherein, the calibration of the horizontal position data of each corner point of the box girder standard segment 1 is specifically that the construction personnel adjusts the position of the box girder standard segment 1 by using the hoisting equipment according to the horizontal position data of the working plane of the box girder, until the center position data of the box girder standard segment 1 corresponds to the horizontal position data of the working plane.

[0025] S3: during hoisting of the box girder standard segment 1, the position data of the box girder standard segment 1 is acquired by the Beidou positioning terminal 2, and the image data of the marker point 6 on the box girder standard segment 1 is acquired by the image acquisition device 5; The position data of the box girder standard segment 1 acquired by each Beidou positioning terminal 2 is subjected to abnormal data elimination by using the 3σ criterion, so as to realize denoising of the position data; the image data of the marker point 6 on the box girder standard segment 1 acquired by the image acquisition device 5 is subjected to denoising by using the Gaussian filter denoising+Canny edge detection mode; wherein, the image data of the marker point 6 on the box girder standard segment 1 acquired by the image acquisition device 5 is used to determine the elevation data of the hoisting of the box girder standard segment 1, and the calculation formula of the elevation data is: In the formula, is the elevation data of the hoisting of the box girder standard segment 1, unit: meter; k is the number of pixels of the marker point 6 increased per meter of hoisting, unit: piece / meter; is the increment of the number of marking points 6 in the hoisting process, unit: pieces; b is the initial elevation data of the box girder standard segment 1, unit: meters; The time calibration is taken as two adjacent time points t i and t i+1 of the position data collected by the Beidou positioning system as the reference, and the image data collected by the image acquisition device 5 is determined by using the following formula: In the formula, is the image data collected by the image acquisition device 5 at time t, unit: pixels; is the image data collected by the image acquisition device 5 at time t , unit: pixels; is the image data collected by the image acquisition device 5 at time (i+1), unit: pixels; t i and t i+1 are two adjacent time points when the position data is collected by the Beidou positioning system, unit: seconds; According to the calibration position data, the first center position coordinates of the box girder standard segment 1 under the Beidou positioning system are determined, and according to the calibration image data, the second spatial position coordinates of the box girder standard segment 1 under the image acquisition device 5 are determined; S4: Calculate the weight of the first center position and the weight of the second spatial position, and calculate the fusion position coordinates according to the weight of the first center position, the first center position coordinates, the weight of the second spatial position and the second spatial position coordinates; S5: According to the fusion position coordinates, adjust the box girder standard segment 1 in the hoisting process of the box girder standard segment 1.

[0026] In the above step S3, the determination process of the first center position coordinates and the second spatial position coordinates is as follows: According to the calibration position data, the coordinates at the center position of the box girder standard segment 1 are calculated as the first center position coordinates (X BD , Y BD , Z BD ), wherein the first center position coordinates (X BD , Y BD , Z BD ) are the average values of the measurement data of the four Beidou positioning terminals 2, and specifically, the first center position coordinates (X BD , Y BD , Z BD ) are calculated by the following formula: in,( ) is the first Beidou positioning terminal 2 in t i Location data measured at any time; ) for the second Beidou positioning terminal 2 in t i Location data measured at any time; ) is the third Beidou positioning terminal 2 in t i Location data measured at any time; ) is the fourth Beidou positioning terminal 2 in t i Location data measured at any given time; Obtain the extrinsic parameter matrix T of image acquisition device 5, and determine the second spatial position coordinates (X) based on the calibration image data (u, v, p) using the following formula. vis Y vis Z vis ); In the formula, u represents the number of pixels of marker point 6 in the X direction in the calibration image data (unit: pixels); v represents the number of pixels of marker point 6 in the Y direction in the calibration image data (unit: pixels); p represents the number of pixels of marker point 6 in the Z direction in the calibration image data (unit: pixels); and T is the external parameter matrix of the image acquisition device 5, which is dimensionless. The calibration image data (u, v, p) is determined by averaging the number of pixels of marker point 6 in the X, Y, and Z directions acquired by the four image acquisition devices 5.

[0027] In step S4 above, the weight of the first center position includes the weight of the first horizontal center position ω1 and the weight of the first vertical center position ω3; the weight of the second spatial position includes the weight of the second horizontal spatial position ω2 and the weight of the second vertical spatial position ω4. The weights ω1 for the first level center position and ω2 for the second level spatial position are both based on the first level confidence level C. SBD Second level credibility C Svis Certain; Level 1 confidence level C SBD It is based on the coordinates of the first center position (X) BD Y BD The second level confidence level C is determined by the standard deviation of the standard deviation. Svis It is based on the (X) coordinates in the second spatial location. vis Y vis The standard deviation is determined by the standard deviation of the sample. The weight ω3 for the first vertical center position and the weight ω4 for the second vertical spatial position are both based on the first vertical reliability C. ZBD Second vertical credibility C Zvis Certain; First vertical confidence level C ZBD It is based on the Z coordinate of the first center position.BD second vertical reliability C Zvis is determined according to the standard deviation of Z vis in the second spatial position coordinate.

[0028] first horizontal reliability C BD , Y BD in the first central position coordinate. SBD The calculation formula of C In the formula, is the standard deviation calculated by using (X BD , Y BD ) in the first central position coordinate, unit: m; is the first horizontal reliability, unit: m -1 ; second horizontal reliability C vis is determined according to the standard deviation of (X vis , Y vis ) in the second spatial position coordinate. Svis The calculation formula of C In the formula, is the standard deviation calculated by using (X vis , Y vis ) in the second spatial position coordinate, unit: m; is the second horizontal reliability, unit: m -1 ; first vertical reliability C ZBD is determined according to the standard deviation of Z BD in the first central position coordinate. In the formula, is the standard deviation calculated by using Z BD in the first central position coordinate, unit: m; is the first vertical reliability, unit: m -1 ; second vertical reliability C Zvis is determined according to the standard deviation of Z vis in the second spatial position coordinate. In the formula, is the standard deviation calculated by using Z vis in the second spatial position coordinate, unit: m; is the second vertical reliability, unit: m -1 .

[0029] According to the first horizontal confidence C SBD and the second horizontal confidence C Svis The calculation formula of the first horizontal center position weight ω1 is: According to the first horizontal confidence C SBD and the second horizontal confidence C Svis The calculation formula of the second horizontal spatial position weight ω2 is: According to the first vertical confidence C ZBD and the second vertical confidence C Zvis The calculation formula of the first vertical center position weight ω3 is: According to the first vertical confidence C ZBD and the second vertical confidence C Zvis The calculation formula of the second vertical spatial position weight ω4 is: In the above step S4, the fusion position coordinates (X R , Y R , Z R ) calculated according to the first center position weight, the first center position coordinates, the second spatial position weight and the second spatial position coordinates are: X R = ω1 × X BD + ω2 × X vis Y R = ω1 × Y BD + ω2 × Y vis Z R = ω3 × Z BD + ω4 × Z vis In the formula, ω1 is the first horizontal center position weight, dimensionless; ω2 is the second horizontal spatial position weight, dimensionless; ω3 is the first vertical center position weight, dimensionless; ω4 is the second vertical spatial position weight, dimensionless; X BD , Y BD , Z BD are respectively the values of the first center position coordinates in the X direction, the Y direction and the Z direction, unit: meter; X vis , Y vis , Z vis are respectively the values of the second spatial position coordinates in the X direction, the Y direction and the Z direction, unit: meter; X R , Y R , ZR respectively are the values of the fusion position coordinates in the X direction, Y direction and Z direction, unit: meter.

[0030] In order to determine the reliability of the Beidou-vision fusion box girder hoisting monitoring method, avoid the problem of abnormal data collected by the Beidou positioning system or the image acquisition device 5 leading to deviation of the monitoring result, increase the threshold verification mechanism, calculate the horizontal deviation 、 , if or , it is determined that the data collected by the Beidou positioning system or the image acquisition device 5 is abnormal, and the previous frame (previous time) is used for calculation.

[0031] If the change trend of the data collected by the Beidou positioning system or the image acquisition device 5 for 10 consecutive frames is opposite, the hoisting process is abnormal and needs to be hoisted again.

[0032] Referring to Figure 2 , the application also proposes a Beidou-vision fusion box girder hoisting monitoring system formed based on the above-mentioned Beidou-vision fusion box girder hoisting monitoring method, which comprises a calibration module, a data acquisition and processing module, a fusion calculation module and an adjustment module. The calibration module is used to calibrate the box girder standard section 1 before hoisting, by collecting position data by the Beidou positioning system and collecting image data of the marker point 6 by the image acquisition device 5, wherein the Beidou positioning system and the marker point 6 are arranged on the box girder standard section 1, and the image acquisition device 5 is arranged on the hoisting device. The data acquisition and processing module is used to collect position data of the box girder standard section 1 by the Beidou positioning system and collect image data of the marker point 6 on the box girder standard section 1 by the image acquisition device 5 during the hoisting process of the box girder standard section 1; the position data collected by the Beidou positioning system and the image data collected by the image acquisition device 5 are time calibrated to obtain calibrated position data and calibrated image data; the first center position coordinates of the box girder standard section 1 under the Beidou positioning system are determined according to the calibrated position data, and the second spatial position coordinates of the box girder standard section 1 are determined according to the calibrated image data. The fusion calculation module is used to calculate the weight of the first center position and the weight of the second spatial position, and calculate the fusion position coordinates according to the weight of the first center position, the first center position coordinates, the weight of the second spatial position and the second spatial position coordinates. The adjustment module is used to adjust the box girder standard section 1 during the hoisting process of the box girder standard section 1 according to the fusion position coordinates.

[0033] It should be noted that the Beidou-vision fusion box girder hoisting monitoring system of the present application is completely corresponding to the content of the above-mentioned Beidou-vision fusion box girder hoisting monitoring method. For the specific content of the calibration module, the data acquisition and processing module, the fusion calculation module and the adjustment module not disclosed in detail in the Beidou-vision fusion box girder hoisting monitoring system of the present application, see the description of the above-mentioned Beidou-vision fusion box girder hoisting monitoring method part, the present application will not be repeated here.

[0034] Referring to Figure 3 The present application also proposes a Beidou-vision fusion box girder hoisting risk assessment method, comprising the following steps: An angle sensor 7 is arranged in the X direction and the Y direction of the box girder standard segment 1; a force sensor is arranged at the top of the sling 8; the angle of the box girder standard segment 1 in the X direction is monitored according to the X direction angle sensor 7, and the angle of the box girder standard segment 1 in the Y direction is monitored according to the Y direction angle sensor 7; the tension of the sling 8 is monitored according to the force sensor; A risk monitoring target function of the box girder standard segment 1 is established based on the angle of the box girder standard segment 1 in the X direction, the angle of the box girder standard segment 1 in the Y direction, the tension of the sling 8, and the first central position coordinate and the second spatial position coordinate in the above-mentioned Beidou-vision fusion box girder hoisting monitoring method: In the formula, is the target monitoring value, unit: meter; is the risk weight component of the box girder standard segment 1 in the horizontal direction, dimensionless; is the position deviation of the box girder standard segment 1 in the X direction, unit: meter, ; is the position deviation of the box girder standard segment 1 in the Y direction, unit: meter, ; is the risk weight component of the box girder standard segment 1 in the vertical direction, dimensionless; is the elevation deviation of the box girder standard segment 1, unit: meter, ; is the angle deviation of the box girder standard segment 1 in the X direction, unit: °; is the angle deviation of the box girder standard segment 1 in the Y direction, unit: °; L1 is the width of the box girder standard segment 1, unit: meter; L2 is the length of the box girder standard segment 1, unit: meter; is the tension risk weight component of the sling 8, dimensionless; is the tension deviation of the sling 8, the unit is KN; K is the stiffness of the sling 8, the unit is kN / m; through the historical data of the risk of the horizontal direction of the box girder standard segment 1 in the hoisting process of the box girder standard segment 1, the historical data of the risk of the horizontal direction of the box girder standard segment 1 and the historical data of the risk of the sling 8, it can be obtained that the data of the three risks are quite, therefore, take , which can balance the influence of the three on the hoisting risk.

[0035] The target monitoring value is normalized to obtain a risk prediction index E; and the risk in the hoisting process of the box girder standard segment 1 is evaluated based on the risk prediction index E.

[0036] The calculation formula for normalizing the target monitoring value is: E=E p / E max In the formula, E is the risk prediction index, dimensionless; E p is the target monitoring value, the unit is meter; E max is the maximum value of the target monitoring value, the unit is meter.

[0037] Specifically, the risk in the hoisting process of the box girder standard segment 1 is evaluated based on the risk prediction index E as follows: If 0.3≥E>0, the posture deviation of the box girder standard segment 1 is small, and there is no hoisting risk; If 0.7≥E>0.3, the posture deviation of the box girder standard segment 1 is within the allowable deviation, and the hoisting risk is in the key observation stage; If E>0.7, the posture deviation of the box girder standard segment 1 exceeds the allowable deviation, and there is a hoisting risk.

[0038] In the evaluation process, the allowable upper limit deviation of the horizontal deviation is 8mm, the allowable upper limit deviation of the elevation deviation is 5mm, and the allowable upper limit deviation of the angle deviation of is 0.3°, and the allowable upper limit deviation of the tension deviation of the sling 8 is 50KN.

[0039] The above content is only used to illustrate the technical solutions of the present application, and is not limited to the present application; although the present application has been described in detail with reference to the foregoing, those skilled in the art should understand that they can still modify the technical solutions described above, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present application.

Claims

1. A Beidou-vision fusion box girder hoisting monitoring method, characterized in that, The method comprises the following steps: S1: arranging a Beidou positioning system and a marker point (6) on a box girder standard segment (1), and arranging an image acquisition device (5) on a hoisting device; S2: before hoisting the box girder standard segment (1), performing initial calibration on the box girder standard segment (1) by using position data collected by the Beidou positioning system; S3: during hoisting of the box girder standard segment (1), collecting position data of the box girder standard segment (1) by using the Beidou positioning system, and collecting image data of the marker point (6) on the box girder standard segment (1) by using the image acquisition device (5); performing time calibration on the position data collected by the Beidou positioning system and the image data collected by the image acquisition device (5) to obtain calibrated position data and calibrated image data; determining a first central position coordinate of the box girder standard segment (1) in the Beidou positioning system according to the calibrated position data, and determining a second spatial position coordinate of the box girder standard segment (1) according to the calibrated image data; S4: calculating a weight of the first central position and a weight of the second spatial position, and calculating a fusion position coordinate according to the weight of the first central position, the first central position coordinate, the weight of the second spatial position and the second spatial position coordinate; S5: adjusting the box girder standard segment (1) during hoisting of the box girder standard segment (1) according to the fusion position coordinate.

2. The Beidou-vision fusion box girder hoisting monitoring method according to claim 1, characterized in that, The Beidou positioning system comprises a Beidou positioning terminal (2) and a Beidou positioning base station (3), The step S1 specifically comprises: arranging one Beidou positioning terminal (2) at each of four corner points of the box girder standard segment (1), and arranging the Beidou positioning base station (3) on a working plane of a box girder that has been hoisted; arranging a marker point (6) at each of the four corner points of the box girder standard segment (1), and the position of the marker point (6) does not coincide with the position of the Beidou positioning terminal (2); arranging an image acquisition device (5) at the top of each hoisting cable (8), and the position of the image acquisition device (5) corresponds to the position of the marker point (6), and the image acquisition device (5) is used to collect image data of the corresponding marker point (6).

3. The Beidou-vision fusion box girder hoisting monitoring method according to claim 2, characterized in that, The step S2 specifically comprises: before hoisting the box girder standard segment (1), collecting horizontal position data of each corner point of the box girder standard segment (1) by using the Beidou positioning terminal (2), collecting horizontal position data of the working plane of the box girder by using the Beidou positioning base station (3), and taking the horizontal position data of the working plane of the box girder as a reference to calibrate the horizontal position data of each corner point of the box girder standard segment (1).

4. The Beidou-vision fusion box girder hoisting monitoring method according to claim 1, characterized in that, In the step S3, the time calibration on the position data collected by the Beidou positioning system and the image data collected by the image acquisition device (5) specifically comprises: When collecting position data with the Beidou positioning system, two adjacent times t i and t i+1 are taken as the reference, and the image data collected by the image collection device (5) is determined using the following formula: In the formula, is the image data collected by the image acquisition device (5) at time t, in units of pixels; is the image data collected by the image acquisition device (5) at time t , in units of pixels; is the image data collected by the image acquisition device (5) at time (i+1), in units of pixels; t i and t i+1 are two adjacent times when the Beidou positioning system collects position data, in units of seconds.

5. The Beidou-vision fusion box girder hoisting monitoring method according to claim 1, characterized in that, In the step S3, the determination process of the first central position coordinate and the second spatial position coordinate is as follows: According to the calibration position data, coordinates at the center position of the box girder standard segment (1) are calculated as first center position coordinates (X BD , Y BD , Z BD ). An extrinsic matrix T of the image capturing device (5) is acquired and the second spatial position coordinates (X vis , Y vis , Z vis ) are determined from the calibration image data (u, v, p) using the following equation: In the formula, u is the number of pixels of the marker point (6) in the X direction in the calibrated image data, and the unit is piece; v is the number of pixels of the marker point (6) in the Y direction in the calibrated image data, and the unit is piece; p is the number of pixels of the marker point (6) in the Z direction in the calibrated image data, and the unit is piece; and T is an external parameter matrix of the image acquisition device (5), and is dimensionless. ​ ​ 6. The Beidou-vision fusion box girder hoisting monitoring method according to claim 5, characterized in that, The weight of the first center position includes a first horizontal center position weight ω1 and a first vertical center position weight ω3, and the weight of the second spatial position includes a second horizontal spatial position weight ω2 and a second vertical spatial position weight ω4. The first horizontal center position weight ω1 and the second horizontal spatial position weight ω2 are both determined according to the first horizontal confidence C SBD and the second horizontal confidence C Svis ; the first horizontal confidence C SBD is determined according to the standard deviation of (X BD , Y BD ) in the first center position coordinate, and the second horizontal confidence C Svis is determined according to the standard deviation of (X vis , Y vis ) in the second spatial position coordinate; The first vertical center position weight ω3 and the second vertical spatial position weight ω4 are each determined according to a first vertical confidence C ZBD and a second vertical confidence C Zvis The first vertical confidence C ZBD is determined according to a standard deviation of Z BD in the first center position coordinates, and the second vertical confidence C Zvis is determined according to a standard deviation of Z vis in the second spatial position coordinates.

7. The Beidou-vision fusion box girder hoisting monitoring method according to claim 6, characterized in that, The fused position coordinates (X R , Y R , Z R ) calculated according to the weight of the first center position, the first center position coordinates, the weight of the second spatial position, and the second spatial position coordinates in the step S4 are: X R = ω1 x X BD + ω2 x X vis Y R = ω1 x Y BD + ω2 x Y vis Z R = ω3 x Z BD + ω4 x Z vis In the formula, ω1 is a first horizontal center position weight, dimensionless; ω2 is a second horizontal spatial position weight, dimensionless; ω3 is a first vertical center position weight, dimensionless; ω4 is a second vertical spatial position weight, dimensionless; X BD , Y BD , and Z BD are values of the first center position coordinates in the X direction, the Y direction, and the Z direction, respectively, with units of meters; X vis , Y vis , and Z vis are values of the second spatial position coordinates in the X direction, the Y direction, and the Z direction, respectively, with units of meters; X R , Y R , and Z R are values of the fused position coordinates in the X direction, the Y direction, and the Z direction, respectively, with units of meters.

8. The Beidou-vision fusion box girder hoisting monitoring system formed based on the Beidou-vision fusion box girder hoisting monitoring method of claim 1, characterized in that, Comprise: The calibration module is used for initial calibration of the box girder standard segment (1) by position data collected by the Beidou positioning system and image data of the marker points (6) collected by the image acquisition device (5) before hoisting of the box girder standard segment (1), wherein the Beidou positioning system and the marker points (6) are arranged on the box girder standard segment (1), and the image acquisition device (5) is arranged on the hoisting device; The data acquisition and processing module is used for collecting position data of the box girder standard segment (1) by the Beidou positioning system and collecting image data of the marker points (6) on the box girder standard segment (1) by the image acquisition device (5) during hoisting of the box girder standard segment (1); the position data collected by the Beidou positioning system and the image data collected by the image acquisition device (5) are time calibrated to obtain calibrated position data and calibrated image data; the first center position coordinates of the box girder standard segment (1) under the Beidou positioning system are determined according to the calibrated position data, and the second spatial position coordinates of the box girder standard segment (1) under the image acquisition device (5) are determined according to the calibrated image data; The fusion calculation module is used for calculating the weight of the first center position and the weight of the second spatial position, and calculating the fusion position coordinates according to the weight of the first center position, the first center position coordinates, the weight of the second spatial position and the second spatial position coordinates; And the adjusting module is used for adjusting the box girder standard segment (1) during hoisting of the box girder standard segment (1) according to the fusion position coordinates.

9. A Beidou-vision fusion box girder hoisting risk assessment method, characterized in that, Comprise the following steps: Angle sensors (7) are arranged in the X direction and the Y direction of the box girder standard segment (1); a force sensor is arranged at the top of the sling (8); the angle of the box girder standard segment (1) in the X direction is monitored according to the angle sensor (7) in the X direction, and the angle of the box girder standard segment (1) in the Y direction is monitored according to the angle sensor (7) in the Y direction; the tension of the sling (8) is monitored according to the force sensor; A risk monitoring target function of the box girder standard segment (1) is established based on the angle of the box girder standard segment (1) in the X direction, the angle of the box girder standard segment (1) in the Y direction, the tension of the sling (8), and the first center position coordinates and the second spatial position coordinates in the Beidou-vision fusion box girder hoisting monitoring method of claim 1; wherein, is the target monitoring value, unit: meter; is the risk weight component of the box girder standard segment (1) in the horizontal direction, dimensionless; is the position deviation of the box girder standard segment (1) in the X direction, unit: meter, ; is the position deviation of the box girder standard segment (1) in the Y direction, unit: meter, ; is the risk weight component of the box girder standard segment (1) in the vertical direction, dimensionless; is the elevation deviation of the box girder standard segment (1), unit: meter, ; is the angle deviation of the box girder standard segment (1) in the X direction, unit: °; is the angle deviation of the box girder standard segment (1) in the Y direction, unit: °; L1 is the width of the box girder standard segment (1), unit: meter; L2 is the length of the box girder standard segment (1), unit: meter; is the tension risk weight component of the sling (8), dimensionless; is the tension deviation of the sling (8), unit: KN; K is the stiffness of the sling (8), unit: kN / m; The target monitoring value is normalized to obtain a risk prediction index E; the risk of the box girder standard segment (1) during hoisting is evaluated based on the risk prediction index E.

10. The Beidou-vision fusion box girder hoisting risk assessment method according to claim 9, characterized in that, The risk of the box girder standard segment (1) during hoisting is evaluated based on the risk prediction index E, which is specifically: If 0.3≥E>0, the attitude deviation of the box girder standard segment (1) is small, and there is no hoisting risk; If 0.7≥E>0.3, the attitude deviation of the box girder standard segment (1) is within the allowable deviation, and the hoisting risk is in the stage of key observation; If E>0.7, the attitude deviation of the box girder standard segment (1) is large, and the hoisting risk is in the stage of high risk observation. If E > 0.7, the attitude deviation of the standard segment (1) of the box girder exceeds the allowable deviation, and there is a risk of hoisting.

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