Metal ball calibration device and method applied to millimeter wave ceilometer

Abstract

The invention provides a metal ball calibration device and method applied to a millimeter wave ceilometer, and the device comprises an upper pedestal which is fixed at the bottom of the millimeter wave ceilometer; the lower base is fixed on the ground and is rotationally connected with the upper base; the end part of a main body of the driver is hinged in the lower base, and the end part of a driving part of the driver is hinged in the upper base. According to the technical scheme, conversion of the millimeter wave ceilometer between the calibration state and the working state can be achieved, and when the millimeter wave ceilometer is calibrated, by inclining the angle of the millimeter wave ceilometer, on one hand, the length of the rope between the unmanned aerial vehicle and the metal ball can be reduced; the length of the rope meets the requirement that the unmanned aerial vehicle is located outside the beam irradiation range of the millimeter-wave ceilometer; as the unmanned aerial vehicle is located outside the beam irradiation range, interference sources are reduced, and the test precision is improved; furthermore, due to the reduction of the length of the rope, the controllable degree of the unmanned aerial vehicle on the metal ball is also improved, the accuracy of position control on the metal ball is greatly improved, and the test efficiency is improved.

Description

Technical Field

[0001] The present invention generally relates to the field of meteorological instrument measurement, and in particular to a metal ball calibration device and method for a millimeter wave cloud meter. Background Art

[0002] Millimeter-wave ceilometers use a vertical, overhead observation mode to continuously detect the vertical profiles of various types of non-precipitating clouds and light precipitation. Calibration of millimeter-wave ceilometers requires the use of a metal sphere to simulate the reflective properties of clouds. This process involves suspending the sphere vertically above the millimeter-wave ceilometer via a drone. The millimeter-wave ceilometer collects the reflected signal from the sphere and compares it with the theoretical value. Calibration coefficients are then applied to ensure the millimeter-wave ceilometer's measurement accuracy. However, this method of suspending the sphere vertically overhead has significant flaws.

[0003] First, the distance between the metal ball and the millimeter-wave ceilometer needs to meet far-field test conditions. Under normal conditions, when the millimeter-wave ceilometer is observing vertically overhead, the drone needs to carry the metal ball to a very high position, which places high demands on the performance of the drone. Secondly, to prevent the scattering of the drone itself from affecting the test results, the connection rope between the drone and the metal ball needs to be greater than or equal to three times the spatial resolution of the millimeter-wave ceilometer, which results in a longer rope used for the connection. In this case, the swing amplitude of the metal ball in the air will increase due to the influence of the ambient wind. During the test, the metal ball can easily swing outside the illumination range of the millimeter-wave ceilometer beam, resulting in the inability to measure correct echo data, further reducing the calibration accuracy. Therefore, how to reduce the flight altitude of the drone while avoiding the scattered echo of the drone body and reducing the impact of the ambient wind on the calibration of the metal ball are issues that need to be considered at present. Summary of the Invention

[0004] In view of the above problems in the prior art, the present invention provides a metal ball calibration device for millimeter wave cloud meter, comprising:

[0005] an upper base, fixed to the bottom of the millimeter wave cloud meter;

[0006] A lower base, fixed on the ground and rotatably connected to the upper base;

[0007] The driver has a main body end hinged in the lower base, and a driving part end hinged in the upper base. By having the above technical features, the millimeter wave cloud meter can be switched between the calibration state and the working state. When the millimeter wave cloud meter is calibrated, the driver tilts the millimeter wave cloud meter to a certain angle, which can reduce the flying height of the UAV on the one hand, and reduce the length of the rope between the UAV and the metal ball on the other hand, so that the rope length is sufficient to ensure that the UAV is outside the beam illumination range of the millimeter wave cloud meter. Moreover, since the UAV is outside the beam illumination range, the interference source is reduced, and the test accuracy is improved. Furthermore, the reduction in flying height and rope length also improves the controllability of the UAV over the metal ball, greatly improving the accuracy of the metal ball control and improving the test efficiency.

[0008] In some embodiments, the upper base comprises:

[0009] An upper chassis, which is fixed to the bottom of the millimeter wave cloud meter; and further comprising:

[0010] A plurality of auxiliary connecting arms are provided, and one end of each auxiliary connecting arm is fixed to the edge of the upper chassis and to the peripheral side of the millimeter wave cloud meter.

[0011] Therefore, by fixing the millimeter-wave cloud meter to the sides and bottom at the same time, the fixing area of the millimeter-wave cloud meter is increased, and the fixing strength of the upper base and the millimeter-wave cloud meter is further improved, so that when the tilt angle of the millimeter-wave cloud meter is adjusted, the state of the millimeter-wave cloud meter is more stable.

[0012] In some embodiments, each auxiliary connecting arm is slidably connected to a stopper along its length, and a stopper sleeve is fixed to the upper surface of the lower base in an area corresponding to each stopper, into which the stopper is inserted. As a result, the upper base and the lower base are connected only via the rotating portion and the driver, resulting in a limited connection area. When the millimeter-wave cloud meter remains in a vertical position, the stopper can be inserted into the corresponding stopper sleeve, thereby increasing the connection area between the upper base and the lower base. This not only limits the mutual rotation between the upper base and the lower base, but also improves the stability of the connection and retention between the upper base and the lower base, thereby improving the overall retention stability of the millimeter-wave cloud meter.

[0013] In some embodiments, a pin is inserted into one side of the limiting sleeve and penetrates both the limiting sleeve and the limiting member, thereby limiting the separation of the limiting member from the limiting sleeve and further improving the stability of the upper base and the lower base.

[0014] In some embodiments, each stopper is further secured to an extension that provides auxiliary ground support. Thus, when the stopper is inserted into the corresponding stopper sleeve, the extension rests on the ground around the lower base, thereby increasing the support area between the lower base and the ground and ensuring the stability of the millimeter wave cloud meter.

[0015] In some embodiments, the millimeter wave cloud meter is internally installed with an inclinometer, so that the staff can conveniently understand the tilt angle of the millimeter wave cloud meter through the inclinometer and calculate relevant parameters based on the angle.

[0016] A metal ball calibration method for a millimeter wave cloud meter comprises the following steps:

[0017] Installing a calibration device, installing the calibration device on the bottom of the millimeter wave cloud meter, fixing the millimeter wave cloud meter in a calibration area through the calibration device, and adjusting the tilt azimuth and angle of the millimeter wave cloud meter;

[0018] Calculate flight parameters and determine the latitude and longitude range and altitude of the metal ball based on the tilt azimuth and angle of the millimeter wave cloud meter, the diameter of the metal ball, and the length of the rope between the drone and the metal ball;

[0019] Perform calibration operations, turn on the millimeter-wave cloud meter, and receive and display echo signals in real time on the millimeter-wave cloud meter terminal. Based on flight parameters, the drone lifts the metal ball to the corresponding area using a rope. The drone is controlled to adjust the position of the metal ball until the echo signal is maximized, and the drone's position information is recorded.

[0020] Analyze the calibration results, calculate the straight-line distance between the metal ball and the millimeter-wave cloud meter based on the UAV position information, rope length, and the tilt angle of the millimeter-wave cloud meter, and analyze the difference between the theoretical echo and the measured echo based on the parameter information of the millimeter-wave cloud meter and the metal ball to determine the calibration coefficient of the millimeter-wave cloud meter.

[0021] Therefore, compared with traditional calibration methods, this method greatly reduces the flight altitude of the UAV and the length of the rope connecting the UAV and the metal ball by adjusting the antenna pointing of the millimeter-wave cloud meter. Furthermore, the reduction in flight altitude and rope length indirectly improves the controllability of the UAV in fine-tuning the metal ball, reduces the impact of ambient wind on the metal ball, and improves the stability and accuracy of the calibration process.

[0022] In some embodiments, the end of the rope connecting the drone to the metal ball is fixed inside the metal ball. As the metal ball is a highly reflective target, placing the rope end inside the metal ball reduces obstruction of the outer contour of the metal ball, thereby ensuring clarity and stability of signal reflection from the metal ball.

[0023] In some embodiments, the length of the rope is sufficient to ensure that the metal ball is within the beam illumination range of the millimeter-wave ceilometer. Therefore, the oblique positioning of the millimeter-wave ceilometer makes it easier for the antenna pointing area to escape the drone's illumination. Compared to traditional vertical flight calibration methods, this significantly reduces the drone's flight altitude and the length of the rope.

[0024] It should be understood that the contents described in the Summary of the Invention section are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram showing the working state of a metal ball calibration device applied to a millimeter wave cloud meter according to an embodiment of the present invention is shown;

[0026] Figure 2 A schematic diagram of an initial state of a metal ball calibration device applied to a millimeter wave cloud meter according to an embodiment of the present invention is shown;

[0027] Figure 3 A flow chart of a metal ball calibration method applied to a millimeter wave cloud meter according to an embodiment of the present invention is shown;

[0028] Figure 4 A schematic diagram showing the principle of a metal ball calibration method applied to a millimeter wave cloud meter according to an embodiment of the present invention is shown.

[0029] Explanation of symbols

[0030] 1. Millimeter-wave cloud meter body; 2. Upper base; 21. Upper chassis; 22. Auxiliary connecting arm; 3. Lower base; 31. Support; 4. Driver; 51. Limiting piece; 52. Limiting sleeve; 53. Pin; 54. Extension; 61. Metal ball; 62. Drone; 63. Rope. DETAILED DESCRIPTION

[0031] Hereinafter, preferred embodiments (or implementations) of the present invention will be described in detail with reference to the accompanying drawings.

[0032] Reference below Figures 1-4 The following describes a device and method for calibrating a metal ball 61 used in a millimeter wave cloud meter according to the present invention.

[0033] Figure 1 FIG1 shows a schematic diagram of the working state of a metal ball 61 calibration device applied to a millimeter wave cloud meter according to an embodiment of the present invention. Figure 1As shown, the present embodiment provides a metal ball 61 calibration device for use with a millimeter wave cloud meter, which is fixed to the bottom of the millimeter wave cloud meter body 1. The device includes an upper base 2 located at the bottom of the millimeter wave cloud meter body 1, and a lower base 3 fixed to the ground. The upper base 2 and the lower base 3 are hinged to each other on their sides, and a driver 4 is provided in the middle area of the lower base 3 and connected between the upper base 2 and the lower base 3. The driver 4 can drive the hinged opening and closing of the upper base 2 and the lower base 3 through its own extension and contraction, and control the tilt angle of the millimeter wave cloud meter body 1.

[0034] In some embodiments, the driver 4 is a linear driver 4, which can be a pneumatic cylinder or an oil cylinder. In this embodiment, the driver 4 is preferably an oil cylinder, which has the advantages of large output force, smooth and precise movement, and flexible speed regulation. Since the millimeter wave cloud meter body 1 is cylindrical and its top antenna area occupies a large space, the support and positioning of the oil cylinder are used to ensure the stability of the tilt adjustment of the millimeter wave cloud meter body 1. The end of the oil cylinder body is hinged in the lower base 3, and the end of the telescopic part of the oil cylinder body is hinged in the upper base 2. Through the extension and retraction of the oil cylinder body, the upper base 2 and the lower base 3 are hingedly opened and closed, further realizing the tilt adjustment of the millimeter wave cloud meter body 1.

[0035] Furthermore, the upper base 2 includes an upper chassis 21 fixed to the bottom of the millimeter wave cloud meter body 1. The upper chassis 21 is coaxially arranged with the millimeter wave cloud meter body 1 and fixed to the millimeter wave cloud meter body 1 by bolts. The end of the above-mentioned oil cylinder telescopic shaft is hinged to the upper chassis 21. A plurality of auxiliary connecting arms 22 are also spaced apart on the circumference of the upper chassis 21. One end of the auxiliary connecting arm 22 is fixed to the edge of the upper chassis 21, and the body thereof is attached to the circumference of the millimeter wave cloud meter body 1 and fixed to the millimeter wave cloud meter by bolts. By fixing the plurality of auxiliary connecting arms 22 to the millimeter wave cloud meter, the support area of the upper base 2 and the millimeter wave cloud meter body 1 is increased, so that the fixation between the upper base 2 and the millimeter wave cloud meter body 1 is more firmly, so that the position of the millimeter wave cloud meter body 1 remains more stable when it is tilted.

[0036] Furthermore, in order to facilitate understanding of the tilt angle of the millimeter wave cloud meter body 1, an inclinometer is also installed inside the millimeter wave cloud meter body 1. The inclinometer can be a displayable inclinometer, so that the staff can observe the tilt angle of the millimeter wave cloud meter body 1 outside the millimeter wave cloud meter body 1.

[0037] Furthermore, a plurality of pillars 31 are dispersedly fixed on the lower base 3. When the upper chassis 21 rotates to a state parallel to the lower base 3, the upper surface of the pillars 31 is supported on the bottom surface of the upper chassis 21, thereby sharing the supporting pressure of the driver 4 and ensuring the stability of the rotation support of the upper chassis 21 and the lower base 3.

[0038] Figure 2 The figure shows a schematic diagram of the initial state of a metal ball 61 calibration device applied to a millimeter wave cloud meter according to an embodiment of the present invention. Each auxiliary connecting arm 22 is arranged along the length direction of the millimeter wave cloud meter body 1, and a strip-shaped limiting member 51 is provided on the side thereof facing away from the millimeter wave cloud meter body 1. The limiting member 51 is slidably connected to the auxiliary connecting arm 22 along the length direction of the auxiliary connecting arm 22, and a limiting sleeve 52 is provided on the upper surface of the lower base 3 and in the corresponding area of each limiting member 51. The lower end face of the limiting sleeve 52 is fixed to the lower base 3 and can accommodate the lower end face of the limiting member 51 to be inserted into the corresponding limiting sleeve 52. When the limiting member 51 is inserted into the corresponding limiting sleeve 52, the contact area between the upper base 2 and the lower base 3 is increased, thereby ensuring the stability of the connection between the upper base 2 and the lower base 3, and also limiting the opening and closing between the upper base 2 and the lower base 3.

[0039] Furthermore, a pin 53 is inserted into one side of the limiting sleeve 52, which penetrates the limiting sleeve 52 and the limiting member 51 at the same time. Under the restriction of the pin 53, the support area of the upper base 2 and the lower base 3 is increased, thereby ensuring the stability of the connection between the upper base 2 and the lower base 3, thereby ensuring the stability of the millimeter wave cloud meter support.

[0040] Furthermore, each limiting member 51 has an extension portion 54 extending toward the ground on the side facing away from the millimeter wave cloud meter body 1. When the lower end of the limiting member 51 is inserted into the limiting sleeve 52, the extension portion 54 is supported on the ground to increase the contact range between the lower base 3 and the ground, further improving the stability and firmness of the millimeter wave cloud meter.

[0041] Figure 3 A flow chart of a method for calibrating a metal ball 61 applied to a millimeter wave cloud meter according to an embodiment of the present invention is shown. A method for calibrating a metal ball 61 applied to a millimeter wave cloud meter provided in this embodiment, when applied to the calibration device described above, includes the following steps:

[0042] S1: Install the calibration device and determine the tilt parameters. Based on the installation environment of the millimeter-wave ceilometer 1, determine the specific coordinates, intended tilt direction, and angle of the millimeter-wave ceilometer 1. Then, use the calibration device to secure the upper base 2 to the bottom of the millimeter-wave ceilometer 1 and the lower base 3 to the ground according to the connection relationship disclosed above. The tilt angle α of the millimeter-wave ceilometer 1 is then adjusted.

[0043] S2: Calculate flight parameters. Based on the tilt azimuth and angle of the millimeter-wave cloud meter body 1, the elevation position and height of the metal ball 61 are calculated. The fixed position of the millimeter-wave cloud meter body 1 is determined, along with its latitude and longitude parameters (x, y), the diameter of the metal ball 61, and the length of the rope 63 between the drone 62 and the metal ball 61. Figure 4A schematic diagram showing the principle of a method for calibrating a metal ball 61 applied to a millimeter wave cloud meter body 1 according to an embodiment of the present invention is shown. Figure 4 As shown, the projection ray of the electromagnetic beam of the millimeter wave cloud meter body 1 in the horizontal direction is obtained by the point-slope principle, and the latitude and longitude range and altitude of the final location of the metal ball 61 are determined.

[0044] The metal ball 61 is a commonly used high-reflectivity target, typically made of a metal such as stainless steel. It has a smooth surface, a regular spherical geometry, and a hole for threading the rope 63. The metal ball 61 can strongly reflect the electromagnetic waves emitted by the millimeter-wave cloud meter body 1, generating a clear and stable echo signal.

[0045] Metal ball 61 is suspended from drone 62, which must be capable of carrying the weight of both ball 61 and rope 63. Drone 62 must be able to carry ball 61 to a height above the required far-field test altitude and hover for a period of time. This requires a flight time of at least one hour. Drone 62 must also be equipped with a positioning system and altitude detection, providing real-time latitude, longitude, and altitude data and enabling automatic positioning based on the set latitude, longitude, and altitude.

[0046] Since the latitude and longitude range of the final location of the metal ball 61 is known, the length of the rope 63 connecting the drone 62 and the metal ball 61 can be adjusted so that when the drone 62 suspends the metal ball 61, the height of the drone 62 is outside the beam illumination range of the millimeter wave cloud meter body 1, so as to avoid the scattering of the drone 62 itself affecting the receiving signal of the millimeter wave cloud meter body 1, causing final data interference.

[0047] S3: Perform calibration operations. According to the proposed data, the drone 62, rope 63, and metal ball 61 are fixed to each other, and the end of the rope 63 is fixed inside the metal ball 61 to avoid the rope 63 being blocked by the external structure of the metal ball 61 and affecting the echo data. The millimeter wave cloud meter body 1 is turned on and the echo signal is received and displayed in real time at the terminal of the millimeter wave cloud meter body 1. Turn on the drone 62 and make it fly to the proposed longitude and latitude parameters, and ensure that the metal ball 61 is suspended in the preset area. Control the drone 62 to adjust the position of the metal ball 61 until the echo signal is maximized, and record the position information of the drone 62.

[0048] S4: Analyze the calibration results. Based on the position of the drone 62, the length of the rope 63, and the tilt angle of the millimeter-wave ceilometer 1, the straight-line distance between the metal ball 61 and the millimeter-wave ceilometer 1 is calculated. Based on the parameters of the millimeter-wave ceilometer 1 and the metal ball 61, the difference between the theoretical echo and the measured echo is analyzed to determine the calibration coefficient of the millimeter-wave ceilometer 1.

[0049] Due to the tilt of the millimeter wave cloud meter body 1, the flight altitude of the drone 62 is greatly reduced compared with the traditional calibration method, and the length of the rope 63 connecting the drone 62 and the metal ball 61 is reduced. Furthermore, the shortened length of the rope 63 indirectly improves the controllability of the drone 62 in fine-tuning the metal ball 61, reduces the range of influence of the ambient wind on the rope 63, and improves the stability and accuracy of the test.

[0050] In this specification, the terms "connect," "install," and "fix" should be understood broadly. For example, "connect" can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0051] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A metal ball calibration device for millimeter wave cloud meter, characterized in that: include: An upper base (2) is fixed to the bottom of the millimeter wave cloud meter; A lower base (3) is fixed on the ground and is rotatably connected to the upper base (2); The driver (4) has a main body end hinged in the lower base (3), and a driving part end hinged in the upper base (2).

2. The metal ball calibration device for millimeter wave cloud meter according to claim 1, characterized in that: The upper base (2) comprises: An upper chassis (21) is fixed to the bottom of the millimeter wave cloud meter; and further comprises: A plurality of auxiliary connecting arms (22) are provided, and one end of each auxiliary connecting arm (22) is fixed to the edge of the upper chassis (21) and to the peripheral side of the millimeter wave cloud meter.

3. The metal ball calibration device for millimeter wave cloud meter according to claim 2, characterized in that: Each auxiliary connecting arm (22) is slidably connected to a limiting member (51) along its length direction, and a limiting sleeve (52) is fixed on the upper surface of the lower base (3) in an area corresponding to each limiting member (51) and inserted into the limiting member (51).

4. The metal ball calibration device for millimeter wave cloud meter according to claim 3, characterized in that: A latch (53) is inserted into one side of the limiting sleeve (52) and penetrates both the limiting sleeve (52) and the limiting member (51).

5. The metal ball calibration device for millimeter wave cloud meter according to claim 3, characterized in that: Each limiting member (51) is also fixedly connected to an extension portion (54) for auxiliary ground support.

6. The metal ball calibration device for millimeter wave cloud meter according to claim 1, characterized in that: An inclinometer is installed inside the millimeter wave cloud meter.

7. A metal ball calibration method for a millimeter wave cloud meter, applied to the calibration device according to any one of claims 1 to 6, comprising the following steps: Installing a calibration device, installing the calibration device on the bottom of the millimeter wave cloud meter, fixing the millimeter wave cloud meter in a calibration area through the calibration device, and adjusting the tilt azimuth and angle of the millimeter wave cloud meter; Calculating flight parameters, and determining the latitude and longitude range and altitude of the metal ball (61) according to the tilt azimuth and angle of the millimeter wave cloud meter, the diameter of the metal ball (61), and the length of the rope (63) between the drone (62) and the metal ball; The calibration operation is performed, the millimeter wave cloud meter is turned on, and the echo signal is received and displayed in real time on the millimeter wave cloud meter terminal. According to the flight parameters, the drone (62) lifts the metal ball (61) to the corresponding area through the rope (63), controls the drone (62) to adjust the position of the metal ball (61) until the echo signal is maximum, and records the position information of the drone (62); The calibration results are analyzed, and the straight-line distance between the metal ball (61) and the millimeter wave cloud meter is calculated according to the position information of the UAV (62), the length of the rope (63) and the tilt angle of the millimeter wave cloud meter. Based on the parameter information of the millimeter wave cloud meter and the metal ball, the difference between the theoretical echo and the measured echo is analyzed to determine the calibration coefficient of the millimeter wave cloud meter.

8. The metal ball calibration method for millimeter wave cloud meter according to claim 7, characterized in that: The end of the rope (63) connecting the drone (62) and the metal ball (61) is fixed inside the metal ball (61).

9. The metal ball calibration method for millimeter wave cloud meter according to claim 8, characterized in that: The length of the rope (63) is only sufficient to ensure that the metal ball (61) is located within the range of the millimeter wave cloud meter beam.

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