Multi-source settlement monitoring and early warning device

Abstract

The utility model discloses a multi-source settlement monitoring and early warning device which comprises a multi-rotor unmanned aerial vehicle (1), a radar (2), a laser range finder (4) and a plurality of reflectors (3), the radar (2) and the laser range finder (4) are both fixed on the lower side of the unmanned aerial vehicle (1), and the signal output end of the radar (2) and the signal output end of the laser range finder (4) are both connected with a control system of the unmanned aerial vehicle (1); a three-dimensional electric holder (5) is arranged at the bottom of the unmanned aerial vehicle (1), a control interface of the three-dimensional electric holder (5) is connected with a control system of the unmanned aerial vehicle (1), and the radar (2) and the laser range finder (4) are both fixed to the rotating end of the three-dimensional electric holder (5). The reflector (3) is a corner reflector. The device has the advantages of low debugging difficulty during installation, low maintenance difficulty after installation, convenience in use and good monitoring effect.

Description

Technical Field

[0001] The utility model belongs to the field of ground subsidence monitoring, and in particular relates to a multi-source subsidence monitoring and early warning device. Background Art

[0002] The traditional ground subsidence monitoring system detects the state of soil subsidence through multiple sensors buried deep below the ground. The signals are summarized at the terminal and the subsidence information is output. The disadvantage is that after the sensor fails, it needs to be removed and replaced, which is troublesome to repair. Sometimes it even requires the destruction of the hard paving materials on the ground, which is not only troublesome, but also requires the restoration of the ground, which is also costly.

[0003] In recent years, with the development of drone technology, a system that uses drones to monitor ground subsidence has emerged, such as an automatic subsidence monitoring system with application number 201811190336.3. First, a reference point is established in a geologically stable area, and a laser emitting device is set above the reference point. The laser emitting device emits a horizontal laser. By setting a laser receiving device on the drone, the flight height of the drone relative to the reference point is determined; by setting a passive reflector on the ground in the monitoring area and setting a millimeter-wave radar on the drone, the height of the drone relative to the monitoring area is determined. By comparing the flight height of the drone relative to the reference point and the height of the drone relative to the monitoring area, it can be concluded whether subsidence has occurred in the monitoring area.

[0004] The equipment of the above-mentioned automatic settlement monitoring system is arranged on the ground, and no excavation or restoration of the ground is required for maintenance, which is convenient for maintenance. However, there are also the following defects:

[0005] 1) When the laser emitting device is installed, there is a slight tilt, and the set laser will be tilted accordingly. When the UAV is at different positions on the laser route, it is at different altitudes. That is, the flight altitude value of the UAV relative to the reference point obtained during monitoring is not fixed, which may lead to incorrect conclusions. This will put extremely high demands on the installation of the laser emitting device, and the debugging of the monitoring system during installation is extremely difficult.

[0006] 2) In the city, there are a large number of buildings, and the flight of drones needs to avoid obstacles and fly at a high altitude. Correspondingly, the laser launcher needs to be set at a higher place, relying on a high tower or other buildings. However, no matter what, there is an intermediate structure between the laser launcher and the ground of the reference point. Even if the reference point does not sink, the intermediate structure may be deformed. This deformation can be caused by many factors, such as aging, thermal expansion and contraction. When the intermediate structure is deformed, even if the laser launcher is initially installed accurately and emits a horizontal laser, after a period of time, the laser launcher will no longer emit a horizontal laser, which also causes the flight altitude value of the drone relative to the reference point obtained during monitoring to change, resulting in incorrect conclusions. Therefore, it is necessary to regularly re-debug the laser launcher, and the difficulty of debugging is extremely great, which makes the maintenance of the monitoring system difficult.

[0007] 3) The distance between the benchmark point established in the geologically stable area and the monitoring area in the geologically unstable area is often relatively large. There are a large number of buildings in the city. In order to make the laser emitted by the laser emitting device pass through the monitoring area, it is necessary to find a suitable installation location. The choice of this installation location is very small, and sometimes it cannot even be found, which also brings difficulties to the installation of the monitoring system.

[0008] 4) Since the laser beam of the laser emitting device is thin and the UAV is flying at a high altitude, it is difficult for the personnel on the ground controlling the flight posture of the UAV to observe the UAV and make it difficult for the UAV to fly exactly on the laser route. In addition, the angle must be adjusted to align the laser receiving device with the laser. In addition, the air flow speed at high altitude is relatively fast, and the flight posture of the UAV itself is not easy to control, making the monitoring system inconvenient to use.

[0009] 5) Since the altitude measurement of the UAV depends on the passive reflector set in the monitoring area, the UAV can only measure at a specific position in the monitoring area (directly above the passive reflector). It is a single-source monitoring and cannot detect multiple positions in the monitoring area and then determine the overall settlement state of the monitoring area, so the monitoring effect is good. Utility Model Content

[0010] The purpose of the utility model is to provide a multi-source settlement monitoring and early warning device. The utility model has the advantages of low debugging difficulty during installation, low maintenance difficulty after installation, convenient use and good monitoring effect.

[0011] The technical solution of the utility model is: a multi-source settlement monitoring and early warning device, including a multi-rotor UAV, a radar, a laser rangefinder and multiple reflectors, the radar and the laser rangefinder are both fixed on the lower side of the UAV, and the signal output end of the radar and the signal output end of the laser rangefinder are both connected to the control system of the UAV.

[0012] In the aforementioned multi-source settlement monitoring and early warning device, a three-dimensional electric gimbal is provided at the bottom of the drone, the control interface of the three-dimensional electric gimbal is connected to the control system of the drone, and the radar and laser rangefinder are both fixed at the rotating end of the three-dimensional electric gimbal.

[0013] In the aforementioned multi-source subsidence monitoring and early warning device, the reflector is a corner reflector.

[0014] In the aforementioned multi-source subsidence monitoring and early warning device, there are three reflectors.

[0015] Compared with the prior art, the utility model has multiple reflectors set on the geologically stable area outside the monitoring area. When the UAV flies over the monitoring area, the distance between the UAV and each reflector can be measured by the onboard radar to determine the height of the UAV relative to the fixed point on the geologically stable area. The onboard laser rangefinder measures the height of the UAV relative to the ground of the monitoring area, and the difference between the two heights is monitored to determine whether the ground in the monitoring area has settled. The utility model has the following advantages:

[0016] 1) There is almost no requirement for the installation accuracy of the reflector, as long as it is roughly facing the sky above the monitored area, which greatly reduces the difficulty of debugging when installing the early warning device.

[0017] 2) Due to the low installation accuracy of the reflector, even if there is an intermediate structure for installation between the reflector and the ground, after the intermediate structure is deformed, the radar's transmission signal can still return to the original path after being reflected by the reflector and be received by the radar, so there is no need to re-debug the transmitter, reducing the maintenance difficulty of the early warning device.

[0018] 3) The utility model can determine the height of the UAV relative to a fixed point in a geologically stable area through the distance between the three transmitters and the radar. The UAV does not need to fly at a fixed height. When there are obstacles such as buildings between the transmitter and the UAV, obstacle avoidance can be achieved by raising the flying altitude of the UAV. The installation position of the reflector is not demanding and the site selection range is large, making the installation of the early warning device easy.

[0019] 4) Since the radar has a detection angle, as long as the reflector is within the detection angle range, the radar can determine the distance between the UAV and the transmitter. The position and direction of the UAV do not need to be strictly controlled, which makes it convenient for ground personnel to control the UAV and makes the early warning device easy to use.

[0020] 5) Since the UAV can obtain the height of any position above the monitoring area compared with the fixed point in the geologically stable area, the laser rangefinder detects the distance between the current UAV and the ground of the detection area, so that the utility model can judge the settlement state of any position in the monitoring area, and can perform multi-point measurement and multi-source monitoring to better determine the overall settlement state of the monitoring area, and the monitoring effect is good.

[0021] In summary, the utility model has the advantages of low debugging difficulty during installation, low maintenance difficulty after installation, easy use and good monitoring effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the principle of the utility model in use.

[0023] Figure 2 This is a schematic diagram of the structure of a drone.

[0024] Figure 3 It is a schematic diagram of ground distance measurement when the UAV fuselage is tilted.

[0025] The markings in the attached figure are: 1-UAV, 2-radar, 3-reflector, 4-laser rangefinder, 5-3D electric pan / tilt, 6-monitoring area, 7-geologically stable area. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0027] Embodiment 1. A multi-source settlement monitoring and early warning device, such as Figure 1 As shown, it includes a multi-rotor UAV 1, a radar 2, a laser rangefinder 4 and three reflectors 3, and the signal output end of the radar 2 and the signal output end of the laser rangefinder 4 are both connected to the control system of the UAV 1.

[0028] A three-dimensional electric pan-tilt platform 5 is provided at the bottom of the drone 1, and the radar 2 and the laser rangefinder 4 are both fixed to the rotating end of the three-dimensional electric pan-tilt platform 5. The control interface of the three-dimensional electric pan-tilt platform 5 is connected to the control system of the drone 1. The three-dimensional electric pan-tilt platform 5 is an existing technology, and the aerial camera is fixed to the drone through the three-dimensional electric pan-tilt platform 5.

[0029] The reflector 3 is a corner reflector.

[0030] The drone 1 is a DJI M30 quad-rotor drone.

[0031] Example 2. The method of using Example 1 comprises the following steps:

[0032] a. Establish a three-dimensional coordinate system, with the X-axis and Y-axis of the three-dimensional coordinate system parallel to the horizontal plane.

[0033] b. Find or establish three reference points in the geologically stable area 7. The three reference points are distributed around the monitoring area 6. The three reflectors 3 are fixed to the reference points respectively. The coordinates of the three reflectors 3 in the three-dimensional coordinate system are (x1, y1, z1), (x2, y2, z2), and (x3, y3, z3). The origin of the three-dimensional coordinate system is located on the reflector 3 with the largest horizontal height.

[0034] c. The UAV 1 enters the airspace above the monitoring area 6 , and the altitude of the UAV 1 is controlled so that there are no obstacles between the UAV 1 and the multiple reflectors 3 .

[0035] d. The distance between the drone 1 and the three reflectors 3 is detected by the radar 2, and the three distance values ​​are sent to the control system of the drone 1. The control system calculates the coordinates (x4, y4, z4) of the drone 1 in the three-dimensional coordinate system based on the three distance values ​​and the straight-line distances between adjacent reflectors 3. The drone 1 sends the coordinates (x4, y4, z4) to the receiving end on the ground that is compatible with the drone. Figure 1 As shown in the figure, three reflectors 3 and the drone 1 form a triangular pyramid. Since the positions of the three reflectors 3 are fixed, the distances between adjacent reflectors 3 are fixed, that is, the lengths of the three bases of the triangular pyramid are fixed, and the lengths of the three edges of the triangular pyramid are known, the coordinates of the drone 1 in the coordinate system are unique and can be calculated.

[0036] e. The distance z5 between the drone 1 and the ground is detected by the laser rangefinder 4. The drone 1 sends z5 to the receiving end on the ground that is matched with the drone. By monitoring whether the difference between z5 and z4 (z4 takes the absolute value) changes, it is determined whether the ground in the monitoring area 6 has settled. For example, when monitoring in January last year, the difference between z5 and z4 was 20 meters, and when monitoring in January this year, the difference between z5 and z4 was 19.5 meters. The difference change reached 0.5 meters, which is a large change, proving that the ground has settled; on the contrary, if the difference change is only 0.1 meters, the change is small and within the error range, then it cannot be concluded that the ground has settled.

[0037] In step d, after the drone 1 maintains the hovering state, the detection direction of the radar 2 is changed by the three-dimensional electric pan / tilt platform 5, so that the radar 2 is directed toward the three reflectors 3 in sequence, and three distance values ​​are obtained. Since the radar 2 has a detection angle, the detection direction of the radar 2 does not need to be completely aligned with the reflector 3, and the distance value can be monitored as long as the reflector 3 is within the detection angle.

[0038] In the step e, after the drone 1 maintains the hovering state, the laser rangefinder 4 is swung back and forth once around an axis parallel to the X-axis and once around an axis parallel to the Y-axis through the three-dimensional electric gimbal 5. During the swinging process, the laser rangefinder 4 is continuously started and multiple values ​​are measured, and the smallest value is used as the distance z5 between the drone 1 and the ground.

[0039] like Figure 3 As shown, due to the large and unstable air currents at high altitudes, the fuselage of the drone 1 may be tilted when it is in a hovering state, and the tilt direction is unknown. At this time, there is an angle between the emission direction of the laser rangefinder 4 and the ground, which will cause the measured distance to far exceed the actual distance between the drone 1 and the ground, and the error will increase. By swinging the laser rangefinder 4 in two directions, multiple measurement values ​​are obtained, and the smallest value is used as the distance z5 between the drone 1 and the ground, the error can be reduced and the accuracy of the conclusion can be improved.

[0040] Example 3. Using the method of Example 2, multiple locations in the monitoring area are measured to obtain multiple differences between z5 and z4: △11, △11....△1n. During the next monitoring, the same multiple locations are measured again to obtain multiple differences between z5 and z4: △21, △21....△2n. The overall settlement state of the monitoring area is determined by combining the changes in multiple differences: (△11-△21), (△12-△22)...(△1n-△2n), and the distribution state of multiple locations.

Claims

1. A multi-source settlement monitoring and early warning device, characterized in that: The invention comprises a multi-rotor unmanned aerial vehicle (1), a radar (2), a laser rangefinder (4) and a plurality of reflectors (3), wherein the radar (2) and the laser rangefinder (4) are both fixed on the lower side of the unmanned aerial vehicle (1), and the signal output end of the radar (2) and the signal output end of the laser rangefinder (4) are both connected to the control system of the unmanned aerial vehicle (1).

2. The multi-source settlement monitoring and early warning device according to claim 1 is characterized in that: A three-dimensional electric pan-tilt platform (5) is provided at the bottom of the unmanned aerial vehicle (1); a control interface of the three-dimensional electric pan-tilt platform (5) is connected to a control system of the unmanned aerial vehicle (1); and a radar (2) and a laser rangefinder (4) are both fixed to a rotating end of the three-dimensional electric pan-tilt platform (5).

3. The multi-source settlement monitoring and early warning device according to claim 2 is characterized in that: The reflector (3) is a corner reflector.

4. The multi-source settlement monitoring and early warning device according to claim 2 is characterized in that: There are three reflectors (3).

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