A dual-mode hydrological radar measuring device based on closed-loop attitude adjustment

Abstract

This utility model discloses a dual-mode hydrological radar measurement device based on closed-loop attitude adjustment, belonging to the field of hydrological monitoring technology. It includes a sealed electronic cabin and an attitude adjustment mechanism. A pitch angle adjustment component is located between a bottom fixed base and a rotating base, used to drive the bottom fixed base to pitch and swing horizontally. An azimuth angle adjustment component is connected between the rotating base and the top fixed base, used to drive the rotating base to rotate horizontally vertically. Through a periodic task scheduling mechanism and pre-emptive closed-loop attitude adjustment, it can automatically and cyclically switch between water level measurement mode and flow velocity measurement mode under unattended conditions. Before each measurement, the radar beam is precisely adjusted to the optimal incident angle of the corresponding mode. Simultaneously, the "attitude adjustment first, measurement later" execution logic ensures that each data acquisition is performed under optimal physical conditions, fundamentally improving the measurement accuracy of water level and flow velocity parameters and realizing fully automated continuous hydrological monitoring.

Description

Technical Field

[0001] This utility model relates to the field of hydrological monitoring technology, and more specifically, to a dual-mode hydrological radar measurement device based on closed-loop attitude adjustment. Background Technology

[0002] In the field of hydrological monitoring, non-contact radar measurement technology is widely used due to its high accuracy and low maintenance requirements. Frequency-modulated continuous wave radar calculates distance by measuring the frequency difference between the transmitted wave and the echo, making it suitable for high-precision water level monitoring; Doppler radar measures the radial velocity of the water surface by detecting the frequency shift of the echo signal, making it suitable for flow velocity monitoring.

[0003] Existing technical solutions typically have the following limitations: 1. Fixed Measurement Mode and Beam Pointing: Most hydrological radar equipment has a single function, or although it integrates dual-mode functionality, the spatial pointing angle of its radar antenna is fixed in its mechanical structure. A fixed beam pointing cannot simultaneously meet the optimal incident angle requirements of different measurement modes. The optimal condition for water level measurement is that the radar beam axis is as perpendicular to the water surface as possible to maximize echo energy and simplify the ranging algorithm; while the accuracy of water surface velocity measurement depends on a non-perpendicular, specific incident angle, and requires the beam's projection direction on the horizontal plane to be aligned with the water flow direction.

[0004] 2. Complex installation and calibration with unreliable accuracy: The absolute measurement accuracy of the equipment heavily depends on the initial mechanical leveling and alignment during installation. Even a slight installation tilt can introduce systematic errors. For applications requiring alternating water level and flow velocity measurements, existing solutions typically cannot automatically switch beam directions, relying on manual intervention and making automated continuous monitoring difficult.

[0005] 3. Lack of long-term attitude stability assurance: After long-term outdoor deployment, the installation foundation of the equipment may deform due to changes in ambient temperature, foundation settlement, or structural stress relaxation, causing a slow drift in the radar beam direction. Traditional fixed devices do not have the ability to detect and compensate for such drift, affecting the reliability of long-term measurement data.

[0006] In view of this, the present invention is proposed to solve the above-mentioned technical problems. Utility Model Content

[0007] The purpose of this invention is to provide a dual-mode hydrological radar measurement device based on closed-loop attitude adjustment, so as to solve the technical problem in the prior art where the non-contact radar beam pointing is fixed and it is not convenient to automatically complete the beam pointing switching.

[0008] To achieve the above objectives, this utility model provides the following technical solution: A dual-mode hydrological radar measurement device based on closed-loop attitude control includes: The sealed electronic compartment contains a radar signal processing and control circuit board, which integrates a three-axis accelerometer, a dual-channel micro servo motor driver, a dual-mode radar RF module, and a main control microprocessor. The bottom of the sealed electronic compartment is the radar wave radiation and reception interface. The attitude adjustment mechanism includes a bottom fixed base, a rotating base, a top fixed base, a pitch angle adjustment component, and an azimuth angle adjustment component. The pitch angle adjustment component is located between the bottom fixed base and the rotating base and is used to drive the bottom fixed base to pitch and swing in the horizontal direction. The azimuth angle adjustment component is connected between the rotating base and the top fixed base and is used to drive the rotating base to rotate horizontally in the vertical direction. The sealed electronic compartment is fixed to the bottom of the bottom fixed base.

[0009] Furthermore, the sealed electronic compartment includes a lower ABS plate, a middle frame, and an upper cover. The radar signal processing and control circuit board is fixed to the inner plane of the lower ABS plate by the first bolt, and the outer surface of the lower ABS plate is the radar wave radiation and reception interface. The lower end of the middle frame is fixedly connected to the edge of the bottom ABS plate by a second bolt; The top cover is fixedly connected to the upper end face of the middle frame by the third bolt, and the top cover is fixedly connected to the bottom of the bottom fixing base.

[0010] Furthermore, the pitch angle adjustment component includes two lower semi-circular racks and a lower micro servo motor, with the two lower semi-circular racks symmetrically fixed on the bottom fixed base; The lower micro servo motor is fixedly installed at the bottom of the rotating base. The output shaft of the lower micro servo motor is equipped with a lower drive gear, which meshes with the tooth surface of the lower semi-circular rack. The lower part of the rotating base and the rotation center of the bottom fixed base have bearings, which are rotatably connected by a fourth bolt passing through the inner ring of the bearing.

[0011] Furthermore, the azimuth adjustment component includes two upper semi-circular racks and an upper micro servo motor, with the two upper semi-circular racks symmetrically fixed on the top fixed base; The upper micro servo motor is fixedly installed on the upper part of the rotating base. The upper drive gear is provided on the output shaft of the upper micro servo motor, and the upper drive gear meshes with the tooth surface of the upper semi-circular rack. The lower part of the top fixed base and the upper part of the rotating base have bearings, which are rotatably connected by a fifth bolt passing through the inner ring of the bearing.

[0012] Furthermore, the triaxial accelerometer is soldered onto the radar signal processing and control circuit board. The attitude data output by the triaxial accelerometer is the spatial orientation of the radar wave radiation and receiving interface, including the pitch angle and azimuth angle.

[0013] Furthermore, the side wall of the mid-frame is provided with a waterproof interface, and an aviation plug for power and signal line access is installed inside the waterproof interface.

[0014] Furthermore, the dual-mode radar RF module is electrically connected to the main control microprocessor. The dual-mode radar RF module supports frequency-modulated continuous wave water level measurement mode and continuous wave Doppler flow velocity measurement mode. In the frequency-modulated continuous wave water level measurement mode, the dual-mode radar RF module collects echo signals and transmits them to the main control microprocessor, which then calculates the water level data. In the Doppler flow velocity measurement mode, the dual-mode radar RF module collects echo signals and transmits them to the main control microprocessor, which then calculates the surface flow velocity data.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. A complete closed-loop negative feedback control system was constructed, consisting of "three-axis accelerometer sensing - main control microprocessor deviation calculation - dual servo motor drive adjustment". It can sense the spatial attitude of the radar beam transmitting surface in real time and actively compensate for beam pointing drift caused by factors such as initial installation error, changes in ambient temperature, and foundation settlement. This eliminates systematic errors in long-term operation and ensures the long-term stability of hydrological monitoring data.

[0016] 2. Adopting an integrated design, the dual-mode radar RF module, attitude sensor, dual-axis drive mechanism and waterproof sealing structure are integrated into a single sealed electronic compartment, avoiding the complex wiring and sealing risks of external gimbals. The overall structure is compact, with a size of only 155mm×105mm×80mm, which is convenient for field installation and deployment.

[0017] 3. The requirements for the absolute levelness and initial orientation accuracy of the installation foundation are significantly relaxed, allowing for a certain degree of initial installation deviation. These deviations can be automatically calibrated by the system during its first run. This feature simplifies the complex procedures of on-site installation and commissioning, eliminating the need for professional personnel to perform high-precision mechanical leveling and alignment, reducing the technical requirements for installers, minimizing measurement errors caused by human error, shortening the project construction cycle, and lowering the overall deployment cost.

[0018] 4. Through a built-in periodic task scheduling mechanism and pre-closed-loop attitude adjustment, it can automatically and cyclically switch between water level measurement mode and flow velocity measurement mode under unattended conditions. Before each measurement, the radar beam is precisely adjusted to the optimal incident angle for the corresponding mode (vertical incident for water level measurement, specific oblique incident for flow velocity measurement), solving the problem that existing fixed-beam devices cannot simultaneously achieve optimal geometric conditions for both measurement modes. At the same time, the "attitude adjustment first, measurement later" execution logic ensures that each data acquisition is performed under optimal physical conditions, fundamentally improving the measurement accuracy of water level and flow velocity parameters and realizing fully automated continuous hydrological monitoring. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but do not constitute an undue limitation of the present invention. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings: Figure 1 A schematic diagram of the structure of a dual-mode hydrological radar measurement device based on closed-loop attitude adjustment provided in an embodiment of this application; Figure 2 An exploded view of a dual-mode hydrological radar measurement device based on closed-loop attitude adjustment provided in an embodiment of this application.

[0020] Reference numerals: 1. Bottom ABS plate; 2. Radar signal processing and control circuit board; 3. Middle frame; 4. Aviation connector; 5. Top cover; 6. Bottom fixing base; 7. Lower semi-circular rack; 8. Lower micro servo motor; 9. Rotating base; 10. Upper micro servo motor; 11. Upper semi-circular rack; 12. Top fixing base; 13. Second bolt; 14. First bolt; 15. Third bolt; 16. Fourth bolt; 17. Fifth bolt. Detailed Implementation

[0021] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0022] See Figures 1 to 2As shown, a dual-mode hydrological radar measurement device based on closed-loop attitude adjustment includes a sealed electronic cabin and an attitude adjustment mechanism. A radar signal processing and control circuit board 2 is fixedly installed inside the sealed electronic cabin. The circuit board 2 integrates a triaxial accelerometer, a dual-channel micro servo motor driver, a dual-mode radar RF module, and a main control microprocessor. The bottom of the sealed electronic cabin serves as the radar wave radiation and reception interface. The attitude adjustment mechanism includes a bottom fixed base 6, a rotating base 9, a top fixed base 12, a pitch angle adjustment component, and an azimuth angle adjustment component. The pitch angle adjustment component is located between the bottom fixed base 6 and the rotating base 9, driving the bottom fixed base 6 to pitch and swing horizontally. The azimuth angle adjustment component is connected between the rotating base 9 and the top fixed base 12, driving the rotating base 9 to rotate horizontally vertically. The sealed electronic cabin is fixed to the bottom of the bottom fixed base 6.

[0023] In the above scheme, the top fixed base 12 is fixedly installed directly above the channel. When adjusting the pitch angle, the bottom fixed base 6 is driven to swing in the horizontal direction through the pitch angle adjustment component, which in turn causes the sealed electronic cabin to swing. When adjusting the azimuth angle, the rotating base 9 is driven to rotate horizontally in the vertical direction through the azimuth angle adjustment component, which in turn causes the rotating base 9, the pitch angle adjustment component, the bottom fixed base 6, and the sealed electronic cabin to rotate as a whole. Based on the feedback information from the built-in attitude sensor, the radar antenna transmitting surface is automatically and accurately adjusted to the optimal spatial angle preset for this mode, thereby realizing high-precision, high-stability, and fully automated continuous monitoring of dual-mode hydrological parameters.

[0024] The main control microprocessor is configured to: based on the real-time attitude data of the radar wave radiation and receiving interface fed back by the triaxial accelerometer, control the pitch angle adjustment component and azimuth angle adjustment component respectively through dual-channel micro servo motor drivers to adjust the radar wave radiation and receiving interface to the target attitude corresponding to the current measurement mode. After the deviation between the real-time attitude and the target attitude is less than the preset threshold, control the dual-mode radar RF module to switch to the corresponding measurement mode and perform hydrological parameter measurement.

[0025] See some possible implementations. Figure 2 As shown, the sealed electronic compartment includes a lower ABS plate 1, a middle frame 3, and an upper cover 5. The radar signal processing and control circuit board 2 is fixed to the inner plane of the lower ABS plate 1 by a first bolt 14. The outer surface of the lower ABS plate 1 is the radar wave radiation and reception interface. The lower end of the middle frame 3 is fixedly connected to the edge of the lower ABS plate 1 by a second bolt 13. The upper cover 5 is fixedly connected to the upper end face of the middle frame 3 by a third bolt 15. The upper cover 5 is fixedly connected to the bottom of the bottom fixing base 6.

[0026] See some possible implementations. Figure 2As shown, the pitch angle adjustment assembly includes two lower semi-circular racks 7 and a lower micro servo motor 8. The bottom fixed base 6 has two arc-shaped mounting surfaces. The two lower semi-circular racks 7 are symmetrically fixed on the arc-shaped mounting surfaces on both sides of the bottom fixed base 6. The lower micro servo motor 8 is fixedly mounted on the bottom of the rotating base 9. A lower drive gear is provided on the output shaft of the lower micro servo motor 8. The lower drive gear meshes with the tooth surface of the lower semi-circular rack 7. The lower part of the rotating base 9 and the rotation center of the bottom fixed base 6 have bearings, which are rotatably connected by a fourth bolt 16 passing through the inner ring of the bearing.

[0027] In the above scheme, when adjusting the pitch angle, the lower micro servo motor 8 is started. The lower micro servo motor 8 drives the lower drive gear to rotate through its output shaft. The lower drive gear meshes with the lower semi-circular rack 7. The lower drive gear rotates along the lower semi-circular rack 7, causing the bottom fixed base 6 to swing, thereby causing the bottom fixed base 6 and the entire lower part to pitch and swing. The pitch swing angle range is ±35 degrees.

[0028] See some possible implementations. Figure 2 As shown, the azimuth adjustment assembly includes two upper semi-circular racks 11 and an upper micro servo motor 10. The top fixed base 12 has two arc-shaped mounting surfaces. The two upper semi-circular racks 11 are symmetrically fixed on the arc-shaped mounting surfaces on both sides of the top fixed base 12. The upper micro servo motor 10 is fixedly mounted on the upper part of the rotating base 9. An upper drive gear is provided on the output shaft of the upper micro servo motor 10. The upper drive gear meshes with the tooth surface of the upper semi-circular rack 11. The lower part of the top fixed base 12 and the upper part of the rotating base 9 have bearings, which are rotatably connected by a fifth bolt 17 passing through the inner ring of the bearing. The two outputs of the dual-channel micro servo motor driver are electrically connected to the lower micro servo motor 8 and the upper micro servo motor 10, respectively.

[0029] In the above scheme, when adjusting the azimuth angle, the upper micro servo motor 10 is started. The upper micro servo motor 10 drives the upper drive gear to rotate through its output shaft. The upper drive gear meshes with the upper semi-circular rack 11. The upper drive gear rotates along the upper semi-circular rack 11, driving the rotating base 9 to rotate, thereby driving the rotating base 9 and the entire lower part to rotate horizontally. The horizontal rotation angle range is ±10 degrees.

[0030] The triaxial accelerometer is soldered onto the radar signal processing and control circuit board 2. The attitude data output by the triaxial accelerometer is the spatial orientation of the radar wave radiation and receiving interface, including the pitch angle and azimuth angle.

[0031] See some possible implementations. Figure 2As shown, the side wall of the middle frame 3 is provided with a waterproof interface, and an aviation plug 4 for power and signal line access is installed inside the waterproof interface.

[0032] The dual-mode radar RF module is electrically connected to the main control microprocessor. The dual-mode radar RF module supports frequency modulation continuous wave water level measurement mode and continuous wave Doppler flow velocity measurement mode. In the frequency modulation continuous wave water level measurement mode, the dual-mode radar RF module collects echo signals and transmits them to the main control microprocessor, which then calculates the water level data. In the Doppler flow velocity measurement mode, the dual-mode radar RF module collects echo signals and transmits them to the main control microprocessor, which then calculates the surface flow velocity data.

[0033] Working principle (1) Mapping management of measurement modes and target attitude: The dual-mode radar RF module supports frequency modulated continuous wave (FMCW) water level measurement mode and continuous wave Doppler current velocity measurement mode, as well as their respective unique optimal measurement attitude angles (including pitch and azimuth). These attitude angles are pre-calibrated based on a physical model of the interaction between the radar beam and the water surface. For example, water level measurement requires the beam to be as vertical as possible (pitch angle 0°), while current velocity measurement requires a specific oblique incidence angle (e.g., pitch angle 35°). The system drives the entire measurement task sequence by periodically switching between the two modes through a configurable timer.

[0034] (2) Closed-loop attitude control based on real-time feedback: This is the core of realizing the "attitude adjustment" function. The dual-mode hydrological radar measurement device based on closed-loop attitude adjustment provided in this application takes the radar signal processing and control circuit board 2 as the control center to form a closed-loop negative feedback control system.

[0035] ① Feedback unit: A three-axis accelerometer (such as MMA8452Q) integrated on the radar signal processing and control circuit board 2 senses the spatial attitude of the bottom ABS plate 1 (i.e., the radar wave emitting surface) in real time.

[0036] ②Control unit: The main control microprocessor compares the real-time attitude data read by the three-axis accelerometer with the target attitude in the current measurement mode and calculates the attitude deviation.

[0037] ③ Execution Unit: Based on the attitude deviation, the upper micro servo motor 10 and the lower micro servo motor 8 are driven to move. The upper micro servo motor 10 and the lower micro servo motor 8 perform azimuth rotation and pitch swing respectively through the meshing of the upper drive gear with the upper semi-circular rack 11 and the meshing of the lower drive gear with the lower semi-circular rack 7, thereby changing the radar beam direction.

[0038] ④ The above process continues to cycle (measure-compare-adjust-remeasure) until the deviation between the real-time attitude and the target attitude is less than the set threshold, forming a high-precision "attitude lock" state. This closed-loop mechanism can not only actively align with the preset angle, but also continuously counteract attitude drift caused by installation errors, structural deformation, or external disturbances.

[0039] (3) Precise radar measurement after attitude stabilization: The control program triggers the corresponding radar measurement only after the closed-loop system confirms that the attitude has stabilized within the target tolerance range. At this time, the radar RF front-end is switched to the working state matching the current mode (FMCW or continuous wave Doppler mode), transmits signals and collects water surface echoes. Subsequently, the signal processing algorithm analyzes the echoes and finally calculates the water level or flow velocity data. This "attitude adjustment first, measurement later" sequence ensures that each data acquisition is performed under optimal geometric conditions.

[0040] Specifically: Step S101: The dual-mode hydrological radar measurement device based on closed-loop attitude adjustment is powered on, the main control microprocessor starts, executes the hardware self-test program, and confirms that the MMA8452Q accelerometer sensor, motor drive circuit, and radar RF module are communicating normally. Subsequently, the user-preset operating parameters are loaded.

[0041] Step S102: Measurement mode cycle switching and target attitude setting. The radar signal processing and control circuit board 2 internally maintains a periodic timer and a two-state (water level, flow velocity) mode state machine. Whenever a measurement cycle T ends, the timer overflows, triggering an interrupt, and the state machine automatically switches to another measurement mode. Based on the currently active mode identifier, the radar signal processing and control circuit board 2 retrieves the corresponding set of target attitude angles (target elevation angle θ_target, target azimuth angle φ_target) from the memory.

[0042] Step S103: Read the current real-time attitude data. The main control microprocessor reads the three-axis digital acceleration values ​​output by the MMA8452Q accelerometer sensor via the I2C bus. Using embedded attitude calculation software, the real-time elevation angle θ_current and azimuth angle φ_current of the current radar beam reference plane are calculated.

[0043] Step S104: Calculate the attitude angle deviation. Calculate the difference between the current attitude angle and the target attitude angle respectively: pitch angle deviation Δθ = θ_target - θ_current; azimuth angle deviation Δφ = φ_target - φ_current.

[0044] Step S105: Determine if the attitude meets the measurement requirements. Compare the calculated absolute value of the attitude angle deviation with a preset allowable error threshold ε. The value of ε ranges from 0.1° to 0.5°, and is preferably 0.2° in this embodiment. The judgment condition is: |Δθ|<ε and |Δφ|<ε. If the condition is met, proceed to step S108. If the condition is not met, proceed to the attitude adjustment stage. The angle adjustment accuracy of the attitude adjustment mechanism is better than 0.1°, which can meet the requirements of hydrological measurement for beam pointing accuracy.

[0045] Step S106: Generate motor servo control commands. Based on the deviation (Δθ, Δφ), the main control microprocessor runs a digital closed-loop control algorithm to calculate the required rotation direction and angle for the upper micro servo motor 10 and the lower micro servo motor 8. Subsequently, the corresponding control signals are sent to the upper micro servo motor 10 and the lower micro servo motor 8 through the motor drive circuit.

[0046] Step S107: Closed-loop adjustment of actuator motion and attitude. The upper micro servo motor 10 and / or the lower micro servo motor 8 drive the upper drive gear and / or the lower drive gear to rotate according to the received signal. Through meshing with the upper semi-circular rack 11 and the lower semi-circular rack 7, the attitude is adjusted. After the attitude changes, the process immediately returns to step S103, forming a closed-loop negative feedback.

[0047] Step S108: Initiate radar measurement in the corresponding mode. Once the attitude is stable, the main control microprocessor controls the radar radio frequency module to switch to the mode corresponding to the current cycle (FMCW mode or Doppler mode), emitting electromagnetic waves and receiving water surface echoes.

[0048] Step S109: Radar signal processing and hydrological parameter calculation. The radar echo signal is processed and then subjected to digital signal analysis. In water level measurement mode, the water level value H is calculated. In flow velocity measurement mode, the surface flow velocity V is calculated.

[0049] Step S110: Data Output and Entry into the Next Measurement Cycle. Upload the calculated hydrological data. After completing this measurement, the cycle timer is reset and restarts, waiting for the next cycle T to arrive, automatically switching modes and starting a new round of the process.

[0050] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A dual-mode hydrological radar measurement device based on closed-loop attitude adjustment, characterized in that, include: A sealed electronic cabin is provided, and a radar signal processing and control circuit board (2) is fixedly installed inside the sealed electronic cabin. The radar signal processing and control circuit board (2) integrates a three-axis accelerometer, a dual-channel micro servo motor driver, a dual-mode radar radio frequency module and a main control microprocessor. The bottom of the sealed electronic cabin is the radar wave radiation and reception interface. The attitude adjustment mechanism includes a bottom fixed base (6), a rotating base (9), a top fixed base (12), a pitch angle adjustment component, and an azimuth angle adjustment component. The pitch angle adjustment component is disposed between the bottom fixed base (6) and the rotating base (9) and is used to drive the bottom fixed base (6) to pitch and swing around the horizontal direction. The azimuth angle adjustment component is connected between the rotating base (9) and the top fixed base (12) and is used to drive the rotating base (9) to rotate horizontally around the vertical direction. The sealed electronic cabin is fixed to the bottom of the bottom fixed base (6).

2. The dual-mode hydrological radar measurement device based on closed-loop attitude adjustment according to claim 1, characterized in that, The sealed electronic compartment includes a bottom ABS plate (1), a middle frame (3) and a top cover (5). The radar signal processing and control circuit board (2) is fixed to the inner plane of the bottom ABS plate (1) by a first bolt (14). The outer surface of the bottom ABS plate (1) is the interface for the radiation and reception of radar waves. The lower end of the middle frame (3) is fixedly connected to the edge of the bottom ABS plate (1) by the second bolt (13); The upper cover (5) is fixedly connected to the upper end face of the middle frame (3) by the third bolt (15), and the upper cover (5) is fixedly connected to the bottom of the bottom fixing base (6).

3. The dual-mode hydrological radar measurement device based on closed-loop attitude adjustment according to claim 2, characterized in that, The pitch angle adjustment assembly includes two lower semi-circular racks (7) and a lower micro servo motor (8). The two lower semi-circular racks (7) are symmetrically fixed on the bottom fixed base (6). The lower micro servo motor (8) is fixedly installed at the bottom of the rotating base (9). A lower drive gear is provided on the output shaft of the lower micro servo motor (8). The lower drive gear meshes with the tooth surface of the lower semi-circular rack (7). The lower part of the rotating base (9) and the rotation center of the bottom fixed base (6) are connected by bearings, and are rotated by a fourth bolt (16) passing through the inner ring of the bearing.

4. The dual-mode hydrological radar measurement device based on closed-loop attitude adjustment according to claim 3, characterized in that, The azimuth adjustment assembly includes two upper semi-circular racks (11) and an upper micro servo motor (10). The two upper semi-circular racks (11) are symmetrically fixed on the top fixed base (12). The upper micro servo motor (10) is fixedly installed on the upper part of the rotating base (9). An upper drive gear is provided on the output shaft of the upper micro servo motor (10). The upper drive gear meshes with the tooth surface of the upper semi-circular rack (11). The lower part of the top fixed base (12) and the upper part of the rotating base (9) have bearings, which are rotatably connected by a fifth bolt (17) passing through the inner ring of the bearing.

5. The dual-mode hydrological radar measurement device based on closed-loop attitude adjustment according to claim 1, characterized in that, The triaxial accelerometer is soldered onto the radar signal processing and control circuit board (2). The attitude data output by the triaxial accelerometer is the spatial orientation of the radar wave radiation and receiving interface, including the pitch angle and azimuth angle.

6. The dual-mode hydrological radar measurement device based on closed-loop attitude adjustment according to claim 2, characterized in that, The side wall of the middle frame (3) is provided with a waterproof interface, and an aviation plug (4) for power and signal line access is installed in the waterproof interface.

7. The dual-mode hydrological radar measurement device based on closed-loop attitude adjustment according to claim 5, characterized in that, The dual-mode radar RF module is electrically connected to the main control microprocessor. The dual-mode radar RF module supports frequency modulation continuous wave water level measurement mode and continuous wave Doppler flow velocity measurement mode. In the frequency modulation continuous wave water level measurement mode, the dual-mode radar RF module collects echo signals and transmits them to the main control microprocessor, which then calculates the water level data. In the Doppler flow velocity measurement mode, the dual-mode radar RF module collects echo signals and transmits them to the main control microprocessor, which then calculates the surface flow velocity data.

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