Method and system for expanding effective measurement range of high-precision clinometer

Abstract

The invention discloses a method and system for expanding the effective measurement range of a high-precision inclinometer, and the method comprises the steps: S1, installing the inclinometer on a Y-axis rotary table of a double-axis mechanical rotary table, and fixing a mechanical rotary table base on a target surface; s2, controlling the double-shaft mechanical turntable to adjust the pose of the inclinometer, so that the initial inclination angle data of the inclinometer is within the measuring range of the inclinometer; s3, biaxial inclination angle data of the inclinometer and biaxial rotation angle data, measured by the encoder, of the mechanical rotary table are collected in real time; s4, fusing the inclination angle data and the rotation angle data based on a coordinate transformation model, and calculating an actual inclination angle of the target surface relative to the horizontal plane; and S5, if the data of the clinometer exceed the preset threshold value, controlling the mechanical turntable to reversely adjust the pose, and repeating the steps S3 to S4 until dynamic compensation is completed. The precision short plate of the mechanical rotary table is stripped from the system, so that the whole system reaches the arc second level measurement precision, the large measurement range of + / -dozens of degrees allowed by the physical structure of the mechanical rotary table is obtained, and the performance which cannot be achieved by a traditional single sensor is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of precision measurement and sensor technology, and particularly relates to a method and system for expanding the effective measurement range of a high-precision inclinometer. BACKGROUND

[0002] High-precision inclinometers are widely used in large structure monitoring, precision instrument leveling, specific target pose measurement and other fields. These fields have high requirements for the measurement accuracy and range of the inclinometer. The measurement accuracy is required to be above the angle second level, and the measurement range is required to cover 10° to 90°.

[0003] However, high precision and large range of the measurement device are often contradictory in actual engineering. In order to pursue high measurement accuracy, the measurement range needs to be sacrificed.

[0004] In order to achieve high measurement accuracy of the angle second level, the physical measurement range of the internal sensing element of the inclinometer is usually designed to be very small (for example, ±0.5° or ±5°), which seriously limits its application in large inclination or attitude change scenarios.

[0005] For example, on a large dual-reflector antenna, it is necessary to monitor the dynamic changes of the main surface and the secondary surface attitude angle of the antenna in the 15° to 90° pitch angle range (with a precision requirement of within 1 angle second), so as to adjust the relative pose of the main surface and the secondary surface of the antenna in real time, and ensure that the antenna reaches the high pointing accuracy requirement of the angle second level. However, the existing high-precision inclinometer with a precision within 1 angle second cannot meet the application requirements due to insufficient range.

[0006] Therefore, there is an urgent need for a high-precision inclinometer measurement range expansion scheme that sacrifices small measurement accuracy to obtain a large measurement range. SUMMARY

[0007] In view of the problems in the prior art, the purpose of the present application is to provide a method for expanding the effective measurement range of a high-precision inclinometer to meet the application requirements of the inclinometer in a large range and high-precision angle measurement scenario. Another purpose of the present application is to provide a system for expanding the effective measurement range of a high-precision inclinometer to implement the above method.

[0008] To achieve the above purpose, the present application provides a method for expanding the effective measurement range of a high-precision inclinometer, comprising: S1 mounting the inclinometer on a Y-axis turntable of a dual-axis mechanical turntable, and fixing the base of the mechanical turntable to a target surface; S2 controlling the dual-axis mechanical turntable to adjust the pose of the inclinometer, so that the initial inclination data is within the range of the inclinometer; S3 real-time acquisition of the dual-axis inclination data of the inclinometer , and the dual-axis rotation angle data of the mechanical turntable measured by the encoder ; S4 uses a coordinate transformation model to fuse tilt and rotation data to calculate the actual tilt angle of the target surface relative to the horizontal plane. If the inclinometer data exceeds the preset threshold, control the mechanical turntable to adjust the posture in the opposite direction, and repeat steps S3 and S4 until dynamic compensation is completed.

[0009] Furthermore, the coordinate transformation model described in step S4 is as follows: ; in, For inclinometer measurement data, Turntable rotation angle data measured by the encoder.

[0010] Furthermore, the initial pose adjustment in step S2 includes horizontal calibration: placing the turntable on a standard horizontal platform, adjusting the inclinometer to a dual-axis error ≤ 0.5'', and setting the encoder initial value to zero.

[0011] Furthermore, in step S5, dynamic compensation is achieved through closed-loop control, and the output speed range of the mechanical turntable is from 0.002° / s to 2° / s.

[0012] Furthermore, in step S4, before data fusion, digital filtering and calibration error compensation need to be performed on the tiltmeter and encoder data.

[0013] Furthermore, the method is implemented through a dual-thread architecture, wherein the first thread handles real-time data acquisition and turntable control, and the second thread handles data fusion and human-computer interaction.

[0014] Furthermore, the tiltmeter has a range of ±0.5° and an accuracy of ≤0.5'', and the encoder has a resolution of ≥24bit and an accuracy of ≤0.5''.

[0015] A system for extending the effective measurement range of a high-precision tiltmeter by implementing the above method includes: High-precision inclinometer: used to measure the micro-tilt angle data of a target surface relative to the horizontal plane; Dual-axis mechanical turntable: includes X-axis and Y-axis turntables, used to support and adjust the tiltmeter's posture; High-precision encoder: used to measure the dual-axis rotational angle data of a mechanical turntable; Main control computer: runs human-computer interaction software for data acquisition, algorithm fusion, and turntable control; The system calculates the actual tilt angle of the target plane by fusing data from the inclinometer and encoder.

[0016] Furthermore, the dual-axis mechanical turntable adopts a two-stage reduction drive structure, including a servo motor, a planetary reducer and a gear reducer, with an output speed range of 0.002° / s to 2° / s.

[0017] Furthermore, the system includes a data acquisition and processing module, a human-computer interaction module, a turntable control module, a data storage module, and a communication module.

[0018] This invention removes the precision bottleneck of the mechanical turntable from the system, ultimately enabling the system to achieve an arcsecond-level measurement accuracy. At the same time, it obtains a large measurement range of ± tens of degrees allowed by the physical structure of the mechanical turntable, achieving performance that traditional single sensors cannot match. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a dual-axis mechanical rotary table tooling structure; Figure 2 This is a schematic diagram of a dual-axis mechanical turntable structure; Figure 3 This is the control block diagram of the inclinometer measurement system; Figure 4 This is a block diagram of the inclinometer measurement system. Figure 5 This is a schematic diagram of the coordinate transformation of the inclinometer system; Figure 6 This is a flowchart of the calibration and measurement process for the inclinometer measurement system; Figure 7 A schematic diagram of an embodiment for measuring the attitude of the sub-surface of a large dual-reflector antenna; Figure 8 for Figure 7 A partially enlarged schematic diagram of the tilt measurement system. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] The following combination Figures 1-8 Specific embodiments of the present invention will be described in detail below. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the present invention.

[0024] This invention extends the tilt angle measurement range of a tiltmeter by designing a dual-axis mechanical turntable. Considering the significant difficulty in manufacturing a large-angle mechanical turntable with arcsecond-level precision, a combination of a "standard precision mechanical turntable + high-precision encoder" is employed. The high-precision encoder records the turntable error, and the tiltmeter measurement data and encoder measurement data are fused. Finally, an algorithm is used to obtain the actual measurement result. The mechanical turntable used in this invention is a standard precision mechanical turntable, the encoder is a high-precision encoder, and the tiltmeter is a high-precision tiltmeter.

[0025] This invention provides a method for extending the effective measurement range of a high-precision tiltmeter, comprising: S1 mounts the inclinometer on the Y-axis turntable of the dual-axis mechanical turntable and fixes the mechanical turntable base to the target surface; S2 controls the dual-axis mechanical turntable to adjust the tiltmeter's position and posture, ensuring that its initial tilt angle data is within the tiltmeter's measurement range; S3 acquires dual-axis tilt angle data from the tiltmeter in real time. and encoder-measured dual-axis rotation data of the mechanical turntable. ; S4 uses a coordinate transformation model to fuse tilt and rotation data to calculate the actual tilt angle of the target surface relative to the horizontal plane. If the inclinometer data exceeds the preset threshold, control the mechanical turntable to adjust the posture in the opposite direction, and repeat steps S3 and S4 until dynamic compensation is completed.

[0026] This invention mainly comprises four parts: a high-precision inclinometer, a standard-precision dual-axis mechanical turntable, a high-precision encoder, and human-machine interaction software. The high-precision inclinometer (range ±0.5°, accuracy ≤0.5'') and the high-precision encoder (resolution ≥24bit, accuracy ≤0.5'') are pre-designed devices, while the dual-axis mechanical turntable and the human-machine interaction software are innovatively designed.

[0027] The design of a typical dual-axis mechanical rotary table includes the design of a dual-axis vertically intersecting fixture, the selection and design of a reducer and motor, and the design of a dual-axis rotary table control system. The dual-axis vertically intersecting fixture structure is designed using SOLIDWORKS as a three-dimensional structure with planar intersections, facilitating the installation of the inclinometer, encoder, reducer, and motor. The reducer and motor are selected based on parameters such as the reducer speed ratio and motor speed range, ultimately achieving an output speed range of 0.002° / s to 2° / s for both axes.

[0028] A dual-axis rotary table control system requires selecting a suitable controller based on the motor drive type, encoder communication type, and programming method. This controller then enables coordinated control of the two-axis mechanical rotary table. While the control precision of the mechanical rotary table itself doesn't need to be extremely high, the dual-axis measurement accuracy of the encoder must be guaranteed. A standard precision mechanical rotary table refers to one that achieves angular component-level transmission accuracy through conventional worm gear or gear transmission mechanisms. A high-precision encoder refers to an encoder with a measurement accuracy reaching the arcsecond or even sub-arcsecond level. A high-precision inclinometer refers to an inclinometer with a measurement accuracy reaching the arcsecond or even sub-arcsecond level.

[0029] The human-computer interaction software design includes software data interface design, algorithm design, and visual control interface design. The data interface serves as a bridge for communication and data exchange between various parts of the system. Based on the application scenarios of high-precision inclinometers in large bridges, radar antennas, etc., the data interface supports remote transmission and real-time acquisition of inclinometer and encoder measurement data.

[0030] Algorithm design is the core of data processing and functional logic. The data directly measured in this invention includes inclinometer measurement data and dual-axis encoder measurement data. The actual measurement result of the target surface is determined jointly by the inclinometer measurement data and the rotation angle position of the dual-axis mechanical turntable. The final measurement result is calculated by designing relevant algorithms. The visual control interface design includes real-time visualization of inclinometer and turntable dual-axis data display, display of the system's final measurement result, and other related content. It also includes functions such as inclinometer range exceeding warning and manual control of the dual-axis mechanical turntable.

[0031] The dual-axis mechanical rotary table design includes: 1. Turntable structure design In high-precision tilt measurement, for tilt measurement objects with a large dynamic range, a dual-axis mechanical turntable is needed to perform coarse compensation of the dynamic range to ensure that the high-precision tilt meter always works within the effective measurement range.

[0032] The dual-axis mechanical rotary table tooling structure designed in this invention is as follows: Figure 1As shown, its structure mainly consists of five components: a fixed base, an X-axis gear reducer, an X-axis turntable, a Y-axis gear reducer, and a Y-axis turntable. One end of the X-axis gear reducer is mounted on the fixed base, and the other end is connected to the X-axis turntable; one end of the Y-axis gear reducer is mounted on the X-axis turntable, and the other end is connected to the Y-axis turntable. Furthermore, the X-axis and Y-axis gear reducers have reserved mounting interfaces for planetary gear reducers and servo motors; the fixed base and X-axis turntable have reserved mounting interfaces for encoders; and the Y-axis turntable has reserved a mounting interface for an inclinometer, facilitating the installation of the inclinometer, encoder, planetary gear reducer, and servo motor.

[0033] The assembly drawing of the dual-axis mechanical rotary table of the present invention is as follows: Figure 2 As shown, the mechanical turntable has dual rotational degrees of freedom around the X and Y axes, which are driven by a geared motor. Considering the difficulty of direct high-precision positioning of the mechanical turntable (there is currently no sub-arcsecond mechanical turntable), a high-precision encoder is cleverly used to accurately measure the dual axes of the turntable, while the adjustment accuracy of the mechanical turntable is not required to be too high. The coarse adjustment accuracy is within the range of ±0.1°.

[0034] To ensure both rapid response and accurate positioning of the turntable, it is necessary to maximize the dual-axis output speed of the turntable (range from 0.002° / s to 2° / s). Therefore, a two-stage reduction drive consisting of a servo motor, a planetary reducer, and a gear reducer is selected. The servo motors include an X-axis servo motor and a Y-axis servo motor; the planetary reducers include an X-axis planetary reducer and a Y-axis planetary reducer; the gear reducers include an X-axis gear reducer and a Y-axis gear reducer; and the encoders include an X-axis encoder and a Y-axis encoder.

[0035] 2. System Parameter Determination and Connection To achieve an output speed of 0.002° / s to 2° / s for the mechanical rotary table, the constant torque output speed range of the motor needs to be determined based on the servo motor's torque-speed curve. This allows for the calculation of the planetary reducer's speed ratio. Using a servo motor with a rated speed of 3000 RPM as the power source, its constant torque output speed range is 0 RPM to 3000 RPM. To avoid overheating at low speeds, the speed range is limited to 3 RPM to 3000 RPM (corresponding to 18° / s to 18000° / s). The required reducer speed ratio is 9000. Considering the large reduction ratio, a two-stage transmission of 10×900 is used. The reduction ratio of 10 is achieved through a gear reducer, and the reduction ratio of 900 is achieved through a planetary reducer.

[0036] A dual-axis mechanical rotary table needs to have automatic control and high-precision angle measurement functions. Servo motors are driven by servo drivers, dual-axis automatic control is achieved through a dual-axis motion control card, and dual-axis angle measurement is achieved through a high-precision encoder. The servo control system connection diagram is as follows: Figure 3As shown, the servo motor and the driver are connected via a power line and a serial bus, the driver and the motion control card are connected via a serial bus, the encoder and the motion control card are connected via a serial bus, and the motion control card and the main control computer are connected via an Ethernet cable.

[0037] Measurement system design: 1. System Algorithm Design A simplified diagram of the coordinate transformation of the inclinometer measurement system is shown below. Figure 5 As shown in the figure, the horizontal coordinate system is marked as O. h X h Y h Z h And mark the initial tilt angle of the inclinometer as .

[0038] The coordinate system O2X2Y2Z2 is derived from the coordinate system O h X h Y h Z h Rotate around the X-axis Then rotate around the Y-axis We obtain that coordinate system O1X1Y1Z1 is formed by rotating coordinate system O2X2Y2Z2 around the Y-axis. Obtain the target plane coordinate system O. p X p Y p Z p It is a rotation of coordinate system O1X1Y1Z1 around the X-axis get.

[0039] According to coordinate transformation theory, the target plane coordinate system O p X p Y p Z p Relative to the horizontal coordinate system O h X h Y h Z h The rotation matrix R can be expressed as: (1) in, and These are the rotation matrices around the X and Y axes, respectively: , (2) According to matrix rotation theory, two consecutive rotations around the Y-axis and The transformations can be combined into a rotation about the Y-axis. The transformation will If we label it as φ, then we have: (3) Replace φ in equation (3) with The final expression for the rotation matrix R is: (4) Let the unit vector of the horizontal plane normal direction be denoted as... The unit vector of the normal direction of the target plane is denoted as ,Right now: (5) because , If all are unit vectors, then their product of magnitudes and lengths... If the value is 1, then the tilt angle of the target plane is... , The angle EL between two vectors can be obtained using the dot product formula: (6) The final mathematical model for the inclination angle of the target plane is as follows: (7) 2. System calibration and measurement process The system for extending the effective measurement range of a high-precision inclinometer requires horizontal calibration before use. The calibration method is to place the system on a standard horizontal platform, adjust the position and orientation of the dual-axis mechanical turntable and the inclinometer so that the inclinometer is in a standard horizontal state (dual-axis error is less than or equal to the maximum measurement error), and set the initial value of the dual-axis encoder of the mechanical turntable to 0 in this state.

[0040] When measuring the target plane, first ensure that there is enough installation area on the target plane, fully fit the base of the system of the present invention to the target plane, and fix the base with clamps or bolts.

[0041] Then, a static measurement threshold for the inclinometer is defined. The threshold range should not be set too large or too small. If the threshold is set too large, or even close to the maximum range, it will cause some measurement results to be distorted during dynamic measurement because the mechanical turntable cannot adjust in time. If the threshold is set too small, or even close to the error range of the mechanical turntable, it will cause the inclinometer to frequently adjust the mechanical turntable during dynamic measurement, or even cause the mechanical turntable to vibrate, leading to the failure of the dynamic measurement process. In this invention, the static measurement threshold of the inclinometer is preferably set to about 2 / 3 of the maximum range. By defining the static measurement threshold of the inclinometer, the system can perform dynamic compensation within the maximum range and check whether the current dual-axis reading of the inclinometer exceeds the threshold. If it exceeds the range, the dual-axis rotation angle of the mechanical turntable is adjusted to bring the inclinometer back within the range.

[0042] Next, the main control computer reads the initial data from the inclinometer and the mechanical turntable encoder, and calculates the initial tilt measurement result of the target plane according to the tilt angle mathematical model in equation (7). For example, the tilt reading of a dual-axis inclinometer with a range of ±0.5° and a measurement accuracy of 0.001° is: , The Y-axis encoder reading of the mechanical turntable, with a measurement accuracy of 0.001°, is... The X-axis encoder reading is Therefore, according to equation (7), the initial value of the inclination angle of the target plane can be calculated to be 31.392. .

[0043] Finally, the main control computer initiates the closed-loop control program for the mechanical turntable, monitoring the inclinometer measurement data in real time and adjusting the mechanical turntable as needed. When the measurement data exceeds the static measurement threshold, the dual-axis mechanical turntable is automatically controlled to adjust its axis angle in the opposite direction of tilting until the inclinometer measurement data returns to the static measurement threshold range. The main control computer then reads the real-time data from the inclinometer and mechanical turntable encoders and calculates the tilt angle data of the target plane based on the algorithm. The calibration and measurement process of the inclinometer measurement system is as follows: Figure 6 As shown.

[0044] Closed-loop control of a mechanical turntable can employ a PID control algorithm. PID control generates a control signal based on the current error, the error integral, and the rate of change of the error. The mathematical expression for a continuous-time position-type PID controller is: (8) In the formula, For controller output, This represents the current position error. For proportional gain, The integral time constant is... The differential time constant is For time, any time in the integral formula is represented by... express.

[0045] To facilitate control implementation, equation (8) is transformed into a difference form mathematical expression as follows: (9) In the formula, The sampling period is For sampling sequence number, For the first The positional error during the sampling, the positional error of any sequence in the summation formula is used... express, For the first Position error during the second sampling.

[0046] In this invention, after the mechanical turntable completes the initial tilt angle measurement, its dynamic position error can be directly measured by a tiltmeter. When the tiltmeter measurement value is within the static measurement threshold, the current position error of the mechanical turntable is considered to be 0, and no adjustment is required; when the tiltmeter measurement value exceeds the static measurement threshold, the Y-axis tilt angle measured by the tiltmeter is regarded as the current angular position error of the mechanical turntable on the Y-axis, and the X-axis tilt angle measured by the tiltmeter is divided by... The cosine result of the target surface tilt angle corresponding to the sampling sequence is regarded as the current angular position error of the X-axis turntable of the mechanical turntable.

[0047] Determining PID controller parameters is a systematic process, typically involving theoretical calculations and experimental tuning, with experimental tuning being more commonly used in practice. Regarding equation (9)... , , The parameter values ​​can be determined by conducting relevant experimental tests according to the classic Ziegler-Nichols method. The experimental steps are as follows: 1) System initialization: Set the controller to pure proportional control (i.e., the integral time constant in equation (9) Let the time be infinity, and the time of differentiation be T. D Set to 0); 2) Critical oscillation test: (1) Adjust the proportional gain of the controller Set it to a small value to stabilize the system; gradually increase it. (3) Record the critical gain at this point until the system output exhibits constant amplitude oscillation (i.e., critical oscillation); and critical oscillation period ; 3) Determine parameters: Based on the ZN rule, based on and set up , , The parameter values ​​are respectively , , .

[0048] This invention relates to a system for extending the effective measurement range of a high-precision inclinometer, with the following architecture design: This system employs a dual-thread architecture, separating the real-time-critical data acquisition and turntable control logic from the lower refresh rate data fusion logic. The main program coordinates the threads, manages global data, and provides the human-machine interface. During data measurement and monitoring in the inclinometer measurement system, it is necessary to read inclinometer and encoder data in real time and determine whether to adjust the dual-axis mechanical turntable based on the real-time monitoring data. Then, the algorithm is invoked to fuse the inclinometer and encoder data to obtain the final measurement result. The entire process is a real-time closed-loop control process. Figure 3This is a control block diagram of the inclinometer measurement system.

[0049] To improve the measurement and early warning effects of the tilt monitoring instrument and ensure its accurate and timely reflection of the structure's tilt status, it needs to be used in conjunction with developed software. This software, combined with the tilt monitoring instrument, improves the accuracy and real-time performance of the monitoring data and enhances the responsiveness of the early warning system. This invention uses Python as the system programming language and QT5 as the system interface development tool. Based on the requirements analysis, the system framework mainly includes a data acquisition and processing module, a human-computer interaction module, a turntable control module, a data storage module, and a communication module. Figure 4 This is a block diagram of the inclinometer measurement system. The functions of each module are as follows: Data acquisition and processing module: It reads sensor data using a hardware interface, uses digital filtering algorithms to filter the acquired data to improve measurement accuracy, and uses calibration coefficients to calibrate the sensor data to eliminate system errors.

[0050] Human-computer interaction module: Uses a graphics library to draw real-time measurement curves of the inclinometer and displays measurement data; uses text boxes or labels to display real-time values; displays processed data in graphical and numerical formats for easy user observation.

[0051] Turntable control module: It checks whether the current dual-axis reading of the inclinometer exceeds the threshold. If it exceeds the range, it adjusts the dual-axis rotation angle of the mechanical turntable. Through interface elements, such as buttons and sliders, it receives user input to control the inclinometer and adjusts it to the range.

[0052] Data storage module: Uses file storage algorithms to store the collected data locally and provides functions such as querying and exporting.

[0053] Communication module: Uses interfaces such as serial communication and Ethernet communication to enable communication with other devices or computers.

[0054] Specific embodiments of the present invention: This invention can be directly applied to the attitude measurement of the sub-reflector of large dual-reflector antennas. The structure of a large dual-reflector antenna mainly consists of an azimuth mount, an elevation mount, a back mount, a main reflector, support legs, and a sub-reflector. Pointing accuracy is a crucial technical performance indicator for large antennas; the highest pointing accuracy requirement for large-aperture, high-frequency antennas is at the arcsecond level. However, due to the influence of gravity, temperature, and wind disturbance, the relative attitude of the main and sub-reflectors of a large antenna undergoes slight deformation, severely affecting the antenna's pointing accuracy. Currently, there is still no highly effective measurement scheme, both domestically and internationally, for the high-precision measurement of the sub-reflector attitude of large antennas. The proposed invention can effectively measure the tilt attitude of the sub-reflector of large antennas.

[0055] like Figure 7The diagram shown is a schematic representation of an embodiment for measuring the attitude of the sub-surface of a large dual-reflector antenna. Figure 8 for Figure 7 A partially enlarged schematic diagram of the tilt measurement system. This is shown when the antenna is in elevation. (The position is directly measured by the pitch encoder) In order to measure the attitude deflection angle Δ of the sub-reflector caused by environmental factors such as gravity, when the position is obtained directly by the pitch encoder. The tilt measurement system is mounted on the back of the sub-reflector of a large antenna. The tilt measurement system is adjusted by a mechanical turntable (rotating along the X-axis). Y-axis rotation ), so that the system's built-in inclinometer is within the static measurement threshold, and the inclinometer reading is ( , The actual tilt angle of the sub-reflector can be calculated according to equation (7). If the value is given, then the tilt angle of the secondary surface caused by environmental factors such as gravity can be expressed as:

[0056] (10) After determining the attitude tilt angle of the sub-reflector of a large antenna, the attitude tilt angle of the sub-reflector can be compensated by adjusting the antenna sub-reflector control mechanism, thereby effectively improving the pointing accuracy of the large antenna.

[0057] Technical effects of the invention: (1) It creatively solved the core technical problem that it was impossible to achieve both high precision and large range in inclinometers. This invention deviates from the traditional high-cost technical path of "developing a high-precision mechanical turntable," instead proposing a novel approach: "ordinary precision actuator + high-precision angle sensing + intelligent data fusion." By using a high-precision encoder (accuracy ≤ 0.5″) to measure the actual rotation angle (including error) of an ordinary precision mechanical turntable in real time and accurately, and then fusing this data with micro-angle measurements from a high-precision inclinometer (accuracy ≤ 0.5″), the invention cleverly eliminates the precision limitation of the mechanical turntable from the system. Ultimately, the system achieves an overall measurement accuracy at the arcsecond level (″), while simultaneously obtaining a large measurement range of ± tens of degrees allowed by the physical structure of the mechanical turntable, achieving performance unattainable by traditional single-sensor systems.

[0058] (2) It significantly reduces the difficulty of system implementation and manufacturing cost, resulting in extremely high cost-effectiveness. The core of this invention lies in the fact that it does not require extremely high motion control precision from the mechanical turntable itself, but only needs to ensure its structural stability and driving function (such as a wide speed range adjustment from 0.002° / s to 2° / s). This greatly reduces the difficulty and cost of machining and assembly. The ultimate accuracy of the system does not depend on expensive ultra-precision bearings and guide rails, but is guaranteed by "standard parts" such as mass-producible high-precision encoders and inclinometers. This design makes it possible to achieve a high-performance measurement system with a low-cost mechanical structure, possessing extremely high engineering application value and market competitiveness.

[0059] (3) It realizes an automated and intelligent measurement process, improving efficiency and reliability. The system achieves closed-loop control throughout the entire process through human-machine interface software. The software monitors the inclinometer data in real time, and once it approaches its ±0.5° limit range, it automatically or manually controls the turntable to return to its original position via a warning prompt. This ensures the high-precision inclinometer always operates within its optimal linear range, avoiding measurement errors or sensor damage caused by exceeding the range. This adaptive posture adjustment capability frees operators from tedious manual leveling and repeated trial and error, reducing human intervention and improving the automation, efficiency, and reliability of the measurement process.

[0060] (4) The system has an advanced architecture, and the measurement data is fused and processed, resulting in more accurate and reliable results. The advantages of this invention lie not only in "range expansion" but also in "accuracy preservation." Its algorithm does not simply add the data from the inclinometer and encoder; instead, it employs deep data fusion based on coordinate transformation and error compensation. This algorithm effectively handles and mitigates the effects of systematic errors such as mechanical turntable backlash and minute deformations, thus achieving a higher overall system accuracy than simple mechanical superposition. The final output is the optimal estimate processed by the intelligent algorithm, rather than a simple accumulation of the original data.

[0061] (5) The technology is highly versatile and has good scalability and platform potential. The system architecture and method proposed in this invention have high versatility. The described dual-axis mechanical turntable design, data interface protocol, and core data fusion algorithm can serve as a general-purpose technical platform. By replacing inclinometers, encoders, or mechanical turntables with different ranges and accuracies, specialized measurement systems suitable for different scenarios (such as civil engineering monitoring, high-end equipment manufacturing, and aerospace leveling) can be quickly derived. The platform has high reusability and is easy to expand applications.

[0062] This invention relates to a method and system for extending the effective measurement range of a high-precision inclinometer. The core technology lies in combining a high-precision inclinometer, a standard-precision mechanical turntable, and a high-precision encoder in a specific system architecture and algorithm logic, thereby extending the inclinometer's measurement range through indirect measurement. The system includes a high-precision inclinometer, a standard-precision dual-axis mechanical turntable, a high-precision encoder, and human-machine interface software. The high-precision inclinometer and encoder are provided by the equipment manufacturer, while the dual-axis mechanical turntable and human-machine interface software are designed independently by this invention. The main function of the high-precision inclinometer is to accurately measure the tilt angle data of the target surface relative to the horizontal plane within a limited measurement range and feed it back to the main control computer. The main function of the dual-axis mechanical turntable is to support the high-precision inclinometer and adaptively adjust its posture. The main function of the high-precision encoder is to accurately measure the dual-axis rotation angle data of the mechanical turntable and feed it back to the human-machine interface software. The main function of the human-machine interface software is to fuse relevant measurement data according to the algorithm, accurately calculate the actual tilt angle data of the target surface, and visualize the relevant measurement data through the human-machine interface. This invention presents a high-precision inclinometer measurement range extension scheme that sacrifices a small amount of measurement accuracy to obtain a larger measurement range. It successfully extends the effective measurement range of the high-precision inclinometer by several orders of magnitude while maintaining arcsecond-level measurement accuracy, which has great practical significance and promotional value.

[0063] Any process or method described in the flowcharts of this invention or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, which can be implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device. The computer-readable medium can be any medium containing a program for storage, communication, propagation, or transmission for use by the execution system, apparatus, or device, including read-only memory, magnetic disks, or optical disks.

[0064] In the description of this specification, references to terms such as "embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, those skilled in the art can combine or combine the different embodiments or examples described in this specification and the features therein without causing contradiction.

[0065] While embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and alterations to the above embodiments within the scope of the present invention.

Claims

1. A method for extending the effective measurement range of a high-precision tiltmeter, characterized in that, The method includes: S1 mounts the inclinometer on the Y-axis turntable of the dual-axis mechanical turntable and fixes the mechanical turntable base to the target surface; S2 controls the dual-axis mechanical turntable to adjust the tiltmeter's position and posture, ensuring that its initial tilt angle data is within the tiltmeter's measurement range; S3 acquires dual-axis tilt angle data from the tiltmeter in real time. and encoder-measured dual-axis rotation data of the mechanical turntable. ; S4 uses a coordinate transformation model to fuse tilt and rotation data to calculate the actual tilt angle of the target surface relative to the horizontal plane. If the inclinometer data exceeds the preset threshold, control the mechanical turntable to adjust the posture in the opposite direction, and repeat S3-S4 until dynamic compensation is completed.

2. The method for extending the effective measurement range of a high-precision tiltmeter according to claim 1, characterized in that, The coordinate transformation model described in step S4 is as follows: in, For inclinometer measurement data, Turntable rotation angle data measured by the encoder.

3. The method for extending the effective measurement range of a high-precision tiltmeter according to claim 1, characterized in that, The initial pose adjustment in step S2 includes horizontal calibration: placing the turntable on a standard horizontal platform, adjusting the inclinometer to a dual-axis error ≤ 0.5'', and setting the encoder initial value to zero.

4. The method for extending the effective measurement range of a high-precision tiltmeter according to claim 1, characterized in that, In step S5, dynamic compensation is achieved through closed-loop control, and the output speed range of the mechanical turntable is from 0.002° / s to 2° / s.

5. The method for extending the effective measurement range of a high-precision tiltmeter according to claim 1, characterized in that, Before data fusion in step S4, digital filtering and calibration error compensation need to be performed on the tiltmeter and encoder data.

6. The method for extending the effective measurement range of a high-precision tiltmeter according to claim 1, characterized in that, The method is implemented through a dual-thread architecture, where the first thread handles real-time data acquisition and turntable control, and the second thread handles data fusion and human-computer interaction.

7. The method for extending the effective measurement range of a high-precision tiltmeter according to claim 1, characterized in that, The tiltmeter has a range of ±0.5° and an accuracy of ≤0.5'', while the encoder has a resolution of ≥24bit and an accuracy of ≤0.5''.

8. A system for extending the effective measurement range of a high-precision inclinometer, characterized in that, The system is used to implement the method for extending the effective measurement range of a high-precision tiltmeter according to any one of claims 1-7, the system comprising: High-precision inclinometer: used to measure the micro-tilt angle data of a target surface relative to the horizontal plane; Dual-axis mechanical turntable: includes X-axis and Y-axis turntables, used to support and adjust the tiltmeter's posture; High-precision encoder: used to measure the dual-axis rotational angle data of a mechanical turntable; Main control computer: runs human-computer interaction software for data acquisition, algorithm fusion, and turntable control; The system calculates the actual tilt angle of the target plane by fusing data from the inclinometer and encoder.

9. The system for extending the effective measurement range of a high-precision tiltmeter according to claim 8, characterized in that, The dual-axis mechanical turntable adopts a two-stage reduction drive structure, including a servo motor, a planetary reducer and a gear reducer, with an output speed range of 0.002° / s to 2° / s.

10. The system for extending the effective measurement range of a high-precision tiltmeter according to claim 8, characterized in that, The system includes a data acquisition and processing module, a human-computer interaction module, a turntable control module, a data storage module, and a communication module.

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