Automatic precise wire shifting test method and device for positive and negative vertical line monitoring system

Abstract

The invention relates to an automatic precise wire shifting test method and device for a positive and negative vertical line monitoring system, and aims to solve the problems of low displacement precision, inaccurate direction control, large disturbance, non-reproducibility, error-prone data recording and the like in the traditional manual wire shifting calibration. The device comprises a base module, a two-dimensional precision motion execution module, a micro-force clamping type end effector, a high-precision grating ruler displacement measurement module and an integrated control and data processing module. Full-closed-loop control is realized by adopting an absolute grating ruler independent of a driving system, constant-force clamping is realized through a V-shaped double-roller micro-force clamping jaw and a force feedback closed loop, the stable state of a vertical line is judged based on S-shaped trajectory planning and spectral analysis, and an automatic multi-point toggle test is executed. According to the invention, micron-sized displacement application and measurement, affine transformation coordinate correction for eliminating installation alignment errors, disturbance minimization in a test process and synchronous and automatic recording of data can be realized, and the calibration precision, repeatability and intelligent level of the plumb line coordinatograph are improved.

Description

Technical Field

[0001] This invention belongs to the field of measurement and monitoring technology, and specifically relates to an automated and precise wire-pulling test method and device for a plumb line monitoring system. Background Technology

[0002] In the safety monitoring system of long-span, high-risk hydraulic structures, especially large hydropower stations and reservoir dams, long-term and accurate monitoring of structural deformation is a core element in ensuring their service safety and assessing their health status. Among numerous deformation monitoring technologies, the plumb line monitoring system remains the benchmark method and key technology for measuring the internal horizontal displacement of tall structures such as dams, particularly the displacement components along and perpendicular to the dam axis, due to its inherent advantages such as intuitive principle, reliable structure, and high measurement accuracy. This system consists of a precision steel wire suspended in an observation corridor inside the dam body and telemetry coordinate instruments installed at different elevations. The coordinate instruments can automatically and in real time read the two-dimensional coordinates of the plumb line relative to a fixed measuring point, thereby retrieving the horizontal displacement of the corresponding elevation section of the dam body. Given the extreme importance of this monitoring data, which directly affects the accuracy of dam safety assessment and early warning decisions, ensuring the long-term stability and reliability of the plumb line telemetry coordinate instruments themselves becomes the fundamental guarantee for the effectiveness of the entire monitoring system.

[0003] Traditional manual wire-pulling testing methods are essentially non-standardized manual operations that rely on the operator's personal experience and skills. They suffer from inherent limitations in multiple dimensions, including displacement accuracy, direction control, system disturbance handling, and operational reproducibility. This mismatch between low-precision testing methods and the high-precision objects being tested makes the entire testing process a weak link in the dam automation monitoring data chain that urgently needs strengthening.

[0004] Therefore, how to abandon the traditional extensive manual operation mode and develop an automated displacement excitation that can apply micron-level, controllable, orthogonal, micro-disturbance to the vertical line and accurately reset it, and simultaneously realize intelligent data recording and processing, so as to build a scientific, rigorous and standardized on-site calibration system for vertical coordinate instruments, has become a key challenge and an urgent technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] To achieve the above objectives, this application provides the following technical solution: According to a first aspect of the present invention, the present invention claims protection for an automated precision wire-pulling test device for a positive and negative plumb line monitoring system, comprising: A base module for stably fixing the device to the vertical coordinate instrument to be measured or to the surface of a fixed structure adjacent to it; The motion execution module is mounted on the base module and is configured to perform precise translational motion in a two-dimensional orthogonal coordinate system; An end effector module is disposed on the moving part of the motion execution module and is used to clamp and release the vertical line with a controlled force; The displacement measurement module is used to measure the absolute position coordinates of the end effector module in the two-dimensional orthogonal coordinate system in real time. The control and data processing module establishes electrical connections and data communication with the motion execution module, the end effector module, and the displacement measurement module, respectively, to precisely control the displacement output of the motion execution module according to the preset test procedure, and to synchronously collect the position feedback data of the displacement measurement module.

[0006] Furthermore, the base module includes: A rigid frame body with a C-shaped or U-shaped geometry, wherein the openings of the frame body are configured to allow the device to be installed from the side of a vertical line without removing the vertical line from its upper and lower fixed ends. At least three independently height-adjustable magnetic fixing feet are provided at the bottom of the frame body. Each magnetic fixing foot has a built-in permanent magnet for magnetically attracting the device to a ferromagnetic surface. The height adjustment mechanism of the foot is used to precisely adjust the initial horizontal posture of the device. The base module also integrates a dual-axis digital tilt sensor, which is electrically connected to the control and data processing module. It is used to output the pitch and roll angle data of the device in real time to assist in the adjustment of the initial horizontal attitude or to input parameters for coordinate transformation algorithms.

[0007] Furthermore, the motion execution module is composed of X-axis linear motion units and Y-axis linear motion units orthogonally stacked, and each linear motion unit includes: Fixed guide rail base; A slide table that reciprocates linearly along the guide rail base; A pre-tightened rolling guide pair used to achieve high rigidity and smooth movement between the guide rail base and the slide table; A drive mechanism consisting of a brushless DC servo motor, a high-precision ball screw pair, and a zero-backlash coupling is used to drive the slide table movement; The displacement measurement module is a direct measurement system independent of the drive mechanism of the motion execution module. Specifically, it includes an X-axis linear displacement sensor and a Y-axis linear displacement sensor respectively installed between the fixed guide rail base and the motion slide of the X-axis linear motion unit and the Y-axis linear motion unit; the linear displacement sensor is an optical grating ruler system or a magnetic grating ruler system.

[0008] Furthermore, the grating ruler system includes a fixed scale grating and a reading head that moves with the slide table; the scale grating is an absolute coded grating ruler made of a substrate material with a low coefficient of thermal expansion, capable of providing absolute position information that is known upon power-on; and the installation position of the reading head follows Abbe's principle, such that its measuring axis is collinear or parallel to the point of action of the perpendicular line clamped by the end effector module in space and is closest to it. The end effector module includes: The Z-axis micro-motion feed unit is used to drive the clamping component to slowly and gently approach the vertical line without impact after the motion execution module completes the two-dimensional planar positioning; and The micro-force gripper unit mounted on the Z-axis micro-motion feed unit is used to perform clamping and releasing operations on the vertical line.

[0009] Furthermore, the micro-force gripper unit adopts a parallel two-finger structure, with each of its two gripping finger tips equipped with a pair of freely rotatable micro rollers arranged in a V-shaped groove. The V-shaped groove arrangement of the micro rollers is configured to automatically position the vertical line to the center of the V-groove during gripping, and the rotatable characteristic of the rollers is used to avoid sliding friction and torsional stress on the surface of the vertical line during gripping. The opening and closing motion of the micro-force gripper unit is driven by a voice coil motor, and a micro-force sensor is integrated in its transmission chain; the control and data processing module performs closed-loop control on the drive current of the voice coil motor based on the real-time feedback signal of the micro-force sensor, so as to achieve constant force clamping on the vertical line.

[0010] Furthermore, the control software embedded within the control and data processing module includes: The multi-axis motion control unit contains a trajectory planner that uses an S-shaped acceleration and deceleration curve algorithm to generate a smooth motion trajectory to suppress mechanical shock and vibration. The feedback signal of its position control loop comes directly from the displacement measurement module to form a fully closed-loop control. The system state identification unit includes a vertical line stability determination algorithm module. This module, after the positioning motion is completed, performs spectral analysis on the high-frequency sampled position data from the displacement measurement module and, based on a preset stability threshold, objectively determines whether the vertical line has returned to a static equilibrium state. The data synchronization and recording unit, upon receiving a stable trigger signal from the system status identification unit, synchronously latches the absolute coordinate readings currently measured by the displacement measurement module, the internal high-precision timestamp, and the measurement readings of the vertical coordinate instrument obtained through the external communication interface within the same system clock cycle.

[0011] According to a second aspect of the present invention, the present invention claims protection for an automated and precise wire-pulling test method for a plumb line monitoring system, comprising the following steps: Device installation and initialization: Install the automated precision line-pulling test device for the positive and negative plumb line monitoring system near the plumb line coordinate instrument to be tested, and perform power-on initialization and horizontal attitude adjustment on the device; Automatic centering and micro-force clamping: The motion execution module of the control device moves the end effector module to the vicinity of the vertical line, and further controls the end effector module to perform stable constant force clamping on the vertical line with a preset micro-target clamping force; Zero-point reference establishment: After clamping is completed and the vertical system is waited for to reach static equilibrium, the absolute coordinate value measured by the displacement measurement module at this moment is recorded and defined as the zero-point reference of the test sequence. Automated multi-point toggle test sequence: For each preset target test point, the following sub-steps are automatically executed in a loop: driving the end effector module to precisely position to the target location, waiting for the vertical system to enter a new static equilibrium state, and simultaneously acquiring and recording the actual coordinate readings of the current device and the readings of the measured vertical coordinate instrument; and Coordinate system relationship identification and data correction: After completing at least three non-collinear test points, the changes in multiple sets of device coordinate readings and the measured coordinate instrument readings are used to establish and solve an affine transformation model between coordinate systems. This model is then used to correct the test data to eliminate alignment errors generated during device installation.

[0012] Furthermore, the automatic centering and micro-force clamping steps specifically include: The Z-axis micro-feed unit within the end effector module is controlled to drive the micro-force gripper unit to approach the vertical line at a preset, extremely low speed. The output signal of the force sensor in the micro-force gripper unit is continuously monitored. When the force value exceeds the preset contact threshold, the feeding of the Z-axis micro-motion feed unit is stopped immediately. The constant force clamping program is started, and the current of the voice coil motor that drives the opening and closing of the micro-force gripper unit is controlled in a closed loop to make the actual clamping force applied to the vertical line accurately and stably stabilized at the preset target force value.

[0013] Furthermore, the waiting step in the automated multi-point toggle test sequence sub-step for the vertical line system to enter a new static equilibrium state is implemented through a vertical line stability determination algorithm, including: After the positioning motion is completed, a sequence of minute position fluctuation data output by the displacement measurement module is continuously collected at a high sampling rate; Online spectral analysis is performed on the position fluctuation data sequence to calculate the power spectral density of the position signal within the natural vibration frequency range of the vertical line; The power spectral density is compared with a preset stability threshold. When the power spectral density is lower than the stability threshold for several consecutive time windows, it is determined that the vertical system has reached a static equilibrium state.

[0014] Furthermore, the method also includes a test result evaluation and report generation step, which includes: Using the identified transformation matrix M and offset vector O, the displacement readings applied by the device in each test are transformed into a coordinate system aligned with the measured vertical coordinate instrument to obtain the corrected true applied displacement value. The corrected actual applied displacement value is compared one-to-one with the reading change value of the measured vertical coordinate instrument to calculate the key performance indicators of the coordinate instrument, such as linearity error, indication error, repeatability, and inter-axis coupling, and a calibration report is generated.

[0015] This invention relates to an automated and precise plumb line alignment test method and apparatus for a plumb line monitoring system, aiming to solve the problems of low displacement accuracy, inaccurate direction control, large disturbances, non-reproducibility, and error-prone data recording in traditional manual plumb line alignment. The invention includes a base module, a two-dimensional precision motion execution module, a micro-force clamping end effector, a high-precision grating ruler displacement measurement module, and an integrated control and data processing module. It employs an absolute grating ruler independent of the drive system to achieve full closed-loop control, uses a V-shaped double-roller micro-force gripper and force feedback closed loop to achieve constant force clamping, and determines the plumb line stability state based on S-shaped trajectory planning and spectrum analysis to perform automated multi-point alignment tests. This invention enables micron-level displacement application and measurement, affine transformation coordinate correction to eliminate installation alignment errors, minimizes test process disturbances, and synchronous automatic data recording, improving the accuracy, repeatability, and intelligence level of plumb line coordinate instrument calibration. Attached Figure Description

[0016] Figure 1 A structural block diagram of an automated precision wire-pulling test device for a positive and negative plumb line monitoring system, as claimed in an embodiment of the present invention; Figure 2 A flowchart illustrating the workflow of an automated and precise wire-pulling test method for a positive and negative plumb line monitoring system, as claimed in an embodiment of the present invention. Figure 3 The second flowchart is a claimed embodiment of the present invention for an automated and precise wire-pulling test method for a plumb line monitoring system. Figure 4The third flowchart is a method for automated and precise wire-pulling testing of a plumb line monitoring system, as claimed in an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0019] To periodically calibrate the measurement accuracy and response linearity of plumb line coordinate instruments, existing industry standards and engineering practices commonly employ an on-site manipulation test method. Specifically, this method involves on-site technicians using simple tools to manually manipulate a naturally suspended plumb line along a predetermined direction by a nominal displacement value, such as 5 mm or 10 mm, without interrupting normal monitoring. After manipulation and stabilization, the operator reads and records the change in the coordinate instrument's reading through the monitoring system and compares it with the applied nominal displacement value to determine whether the coordinate instrument is functioning correctly and whether its response is accurate. At a specific stage of technological development, this manual on-site testing method, due to its simplicity, low cost, and lack of complex equipment, to a certain extent met the basic needs for functional verification of coordinate instruments, providing a direct and feasible verification method for early dam safety monitoring.

[0020] However, with the deepening of dam safety monitoring theory, the development of automated monitoring technology, and increasingly stringent requirements for data quality in the engineering field, the inherent imprecision and non-standardization of the traditional manual line-pulling test method have gradually exposed profound internal contradictions when facing the demands of modern high-precision and high-reliability monitoring. The core of this contradiction lies in the fact that this method attempts to calibrate and verify a precision quantitative measuring instrument with micrometer-level accuracy using a qualitative or semi-qualitative operation where the process cannot be precisely controlled and the results are difficult to quantitatively reproduce. This presents a natural logical dilemma in metrology. The reasons are twofold: First, the accuracy of the applied displacement cannot be guaranteed. Operators rely on visual observation of the ruler scale to control the adjustment distance, which inevitably introduces multiple uncertainties such as parallax, estimation errors, and operational jitter. This results in an unknown and uncontrollable deviation between the actual applied displacement and the nominal value, which may even be on the same order of magnitude as the measurement tolerance of the coordinate instrument itself, thus significantly reducing the validity of the comparison results. Second, the orthogonality of the adjustment direction is difficult to achieve precisely. Within the complex and confined spaces of a dam's gallery, operators struggle to ensure that the adjustment direction is strictly parallel or orthogonal to the dam's coordinate system. Even a slight angular deviation will couple the displacement component in one direction to the measurement reading in another, introducing significant systematic errors. This is extremely detrimental to accurately assessing the independent response characteristics of the coordinate instrument across different axes. Furthermore, manual operation inevitably applies a momentary impact disturbance to the slender plumb line, rather than a gradual static displacement. This easily induces high-frequency oscillations and torsions in the plumb line, requiring a considerable amount of time to recover stability. This not only significantly reduces testing efficiency but also causes discrepancies between the system state during testing and static monitoring. In addition, the method's non-reproducibility is another fundamental drawback. Once the adjustment is complete and released, it is almost impossible for the plumb line to accurately return to its initial equilibrium position. This means that each test is a one-off, irreversible operation, making it impossible to perform repeatable or comparative tests on multiple directions or multiple displacements on the same reference. This severely restricts the ability to comprehensively and systematically calibrate the coordinate instrument's performance.

[0021] According to the first embodiment of the present invention, referring to Figure 1 This invention claims protection for an automated precision wire-pulling test device for a plumb line monitoring system, comprising: A base module for stably fixing the device to the vertical coordinate instrument to be measured or to the surface of a fixed structure adjacent to it; The motion execution module is mounted on the base module and is configured to perform precise translational motion in a two-dimensional orthogonal coordinate system; An end effector module is disposed on the moving part of the motion execution module and is used to clamp and release the vertical line with a controlled force; The displacement measurement module is used to measure the absolute position coordinates of the end effector module in the two-dimensional orthogonal coordinate system in real time. The control and data processing module establishes electrical connections and data communication with the motion execution module, the end effector module, and the displacement measurement module, respectively, to precisely control the displacement output of the motion execution module according to the preset test procedure, and to synchronously collect the position feedback data of the displacement measurement module.

[0022] Furthermore, the base module includes: A rigid frame body with a C-shaped or U-shaped geometry, wherein the openings of the frame body are configured to allow the device to be installed from the side of a vertical line without removing the vertical line from its upper and lower fixed ends. At least three independently height-adjustable magnetic fixing feet are provided at the bottom of the frame body. Each magnetic fixing foot has a built-in permanent magnet for magnetically attracting the device to a ferromagnetic surface. The height adjustment mechanism of the foot is used to precisely adjust the initial horizontal posture of the device. The base module also integrates a dual-axis digital tilt sensor, which is electrically connected to the control and data processing module. It is used to output the pitch and roll angle data of the device in real time to assist in the adjustment of the initial horizontal attitude or to input parameters for coordinate transformation algorithms.

[0023] In this embodiment, the base module includes a rigid frame body with a C-shaped or U-shaped geometry and at least three independently height-adjustable magnetic fixing feet located at the bottom of the frame body. The C-shaped or U-shaped opening design of the frame body is designed to allow the device to be easily installed from the side of the plumb line without removing the plumb line from its upper and lower fixed ends. The frame body is preferably made of a material with high specific stiffness and low coefficient of thermal expansion, such as aged 7075-T6 aluminum alloy or Invar steel, to ensure the dimensional stability of the device under changes in ambient temperature. The ends of the magnetic fixing feet are provided with spherical or hemispherical contact ends and have built-in permanent magnets, such as neodymium iron boron magnets, which are magnetically attracted to the ferromagnetic metal panel of the plumb line coordinate instrument. The height adjustment mechanism of the feet, such as a precision threaded pair, is used to precisely adjust the initial horizontal attitude of the device during installation. In a preferred embodiment of the present invention, a dual-axis digital tilt sensor is also integrated on the base module. The tilt sensor is electrically connected to the control and data processing module. Its real-time output pitch and roll angle data can be used to assist operators in making quick and accurate leveling adjustments, or as initial parameter input for coordinate transformation algorithms.

[0024] Furthermore, the motion execution module is composed of X-axis linear motion units and Y-axis linear motion units orthogonally stacked, and each linear motion unit includes: Fixed guide rail base; A slide table that reciprocates linearly along the guide rail base; A pre-tightened rolling guide pair used to achieve high rigidity and smooth movement between the guide rail base and the slide table; A drive mechanism consisting of a brushless DC servo motor, a high-precision ball screw pair, and a zero-backlash coupling is used to drive the slide table movement; The displacement measurement module is a direct measurement system independent of the drive mechanism of the motion execution module. Specifically, it includes an X-axis linear displacement sensor and a Y-axis linear displacement sensor respectively installed between the fixed guide rail base and the motion slide of the X-axis linear motion unit and the Y-axis linear motion unit; the linear displacement sensor is an optical grating ruler system or a magnetic grating ruler system.

[0025] In this embodiment, the motion execution module is specifically composed of an X-axis linear motion unit and a Y-axis linear motion unit orthogonally stacked. The X-axis and Y-axis linear motion units are structurally and performance-equal. Each unit includes a fixed guide rail base, a slide table that reciprocates linearly along the guide rail base, and a drive mechanism for driving the slide table. To ensure motion smoothness and positioning stiffness, a pre-tightened crossed roller bearing guide rail pair is used between the guide rail base and the slide table. The drive mechanism consists of a brushless DC servo motor, a high-precision ball screw pair, and a zero-backlash coupling for connecting the motor output shaft and the screw. The brushless DC servo motor integrates a high-resolution rotary encoder to form the inner loop of motor control, namely the speed loop and the current loop. By strictly configuring the guide rail directions of the two sets of linear motion units to be mutually perpendicular, a platform capable of achieving high-precision, high-response speed motion in a two-dimensional Cartesian coordinate system is constructed.

[0026] The displacement measurement module does not rely on the rotary encoder of the drive motor for position calculation. Instead, it employs a high-precision linear displacement sensor, independent of the drive chain, that directly measures the absolute displacement of the slide table. Specifically, an independent optical scale system or magnetic scale system is installed between the fixed guide rail base of the X-axis linear motion unit and the moving slide table. Each optical scale system includes a fixed scale grating and a reading head that moves with the slide table. The scale grating is preferably an absolute coded grating scale using a low-expansion glass substrate, which provides absolute position information immediately upon power-on, avoiding the zero-homing operation required by incremental encoders. The resolution of the optical scale system is set to 0.1 micrometers or higher, and its accuracy level after metrological calibration should be significantly better than the nominal accuracy of the measured vertical coordinate instrument. The installation position of the optical scale reading head strictly follows the Abbe principle, that is, its measuring axis and the point of action of the end effector module clamping the vertical line are as collinear or parallel as possible in space and as close as possible to minimize the Abbe error caused by angular deviations during slide table movement.

[0027] Furthermore, the grating ruler system includes a fixed scale grating and a reading head that moves with the slide table; the scale grating is an absolute coded grating ruler made of a substrate material with a low coefficient of thermal expansion, capable of providing absolute position information that is known upon power-on; and the installation position of the reading head follows Abbe's principle, such that its measuring axis is collinear or parallel to the point of action of the perpendicular line clamped by the end effector module in space and is closest to it. The end effector module includes: The Z-axis micro-motion feed unit is used to drive the clamping component to slowly and gently approach the vertical line without impact after the motion execution module completes the two-dimensional planar positioning; and The micro-force gripper unit mounted on the Z-axis micro-motion feed unit is used to perform clamping and releasing operations on the vertical line.

[0028] Furthermore, the micro-force gripper unit adopts a parallel two-finger structure, with each of its two gripping finger tips equipped with a pair of freely rotatable micro rollers arranged in a V-shaped groove. The V-shaped groove arrangement of the micro rollers is configured to automatically position the vertical line to the center of the V-groove during gripping, and the rotatable characteristic of the rollers is used to avoid sliding friction and torsional stress on the surface of the vertical line during gripping. The opening and closing motion of the micro-force gripper unit is driven by a voice coil motor, and a micro-force sensor is integrated in its transmission chain; the control and data processing module performs closed-loop control on the drive current of the voice coil motor based on the real-time feedback signal of the micro-force sensor, so as to achieve constant force clamping on the vertical line.

[0029] In this embodiment, the end effector module features a meticulously designed structure to achieve micro-disturbance and highly repeatable clamping of the vertical line. The end effector module includes a Z-axis micro-feed unit and a micro-force gripper unit mounted thereon. The Z-axis micro-feed unit, such as a piezoelectric ceramic linear actuator with a stroke of several hundred micrometers, is used to achieve a final, slow, and impact-free flexible approach of the gripper towards the vertical line after two-dimensional motion positioning. The micro-force gripper unit employs a parallel two-finger structure, with each of its two gripping fingers equipped with a pair of freely rotatable micro-rollers arranged in a V-shaped groove. The rollers are made of a polymer material with a low coefficient of friction and high wear resistance, such as polyetheretherketone (PEEK), and are embedded in micro-ball bearings. This V-shaped double-roller structure automatically positions the vertical line to the center of the V-groove during clamping, and the rotatable nature of the rollers avoids sliding friction and torsional stress on the surface of the vertical line during clamping. The opening and closing motion of the grippers is driven by a voice coil motor, and a miniature force sensor, such as a force-sensitive element based on strain gauge technology, is integrated into its transmission chain. This force sensor can monitor the actual clamping force applied to the vertical line by the gripping fingertips in real time. Based on the feedback signal from the force sensor, the control and data processing module performs closed-loop control on the drive current of the voice coil motor, thereby achieving constant force clamping on the vertical line with extremely high accuracy and repeatability, fundamentally avoiding interference with the vertical line's balance state caused by excessive or inconsistent clamping forces.

[0030] Furthermore, the control software embedded within the control and data processing module includes: The multi-axis motion control unit contains a trajectory planner that uses an S-shaped acceleration and deceleration curve algorithm to generate a smooth motion trajectory to suppress mechanical shock and vibration. The feedback signal of its position control loop comes directly from the displacement measurement module to form a fully closed-loop control. The system state identification unit includes a vertical line stability determination algorithm module. This module, after the positioning motion is completed, performs spectral analysis on the high-frequency sampled position data from the displacement measurement module and, based on a preset stability threshold, objectively determines whether the vertical line has returned to a static equilibrium state. The data synchronization and recording unit, upon receiving a stable trigger signal from the system status identification unit, synchronously latches the absolute coordinate readings currently measured by the displacement measurement module, the internal high-precision timestamp, and the measurement readings of the vertical coordinate instrument obtained through the external communication interface within the same system clock cycle.

[0031] In this embodiment, the control and data processing module is the central hub for realizing the automation and intelligent functions of this invention. Its hardware core is an embedded controller with real-time processing capabilities, such as a System-on-a-Chip (SoC) based on a Field-Programmable Gate Array (FPGA) and an Advanced Reduced Instruction Set Machine (ARM) processor architecture. The controller reads the absolute position data of the two-axis linear encoders through a dedicated high-speed digital interface, sends motion commands to the two-axis servo drivers via a Digital-to-Analog Converter (DAC) or fieldbus, and acquires feedback signals from the force sensors via an Analog-to-Digital Converter (ADC). The controller internally runs a complex and precise control software, which functionally includes at least a multi-axis motion control unit, a system status identification unit, a data synchronization and recording unit, and a human-machine interface and task management unit.

[0032] The multi-axis motion control unit is responsible for parsing the upper-level task commands into smooth motion trajectories. Internally, it includes a trajectory planner that employs an S-shaped acceleration / deceleration curve algorithm. By continuously and smoothly controlling acceleration, it effectively suppresses mechanical shocks and vibrations during motion, thereby minimizing dynamic excitation on the suspended vertical system. The feedback signal of its position control loop comes directly from the grating ruler system, forming a fully closed-loop control system. This ensures a high degree of consistency between the actual position and the commanded position of the end effector, eliminating errors caused by backlash, elastic deformation, and thermal expansion of mechanical transmission components such as ball screws.

[0033] The system state identification unit is the key innovation that distinguishes this invention from simple motion platforms. It contains a vertical line stability determination algorithm module. This module is automatically activated after the controller completes a positioning motion. It continuously acquires the position readings of the grating ruler at a high sampling rate and performs online Fast Fourier Transform (FFT) or other forms of spectral analysis on the data sequence of small position fluctuations over a recent period. It calculates the power spectral density of the position signal within the natural vibration frequency range of the vertical line and compares it with a preset stability threshold. Only when the spectral energy is continuously below this threshold for several time windows does the controller determine that the vertical line has recovered from motion disturbance to a static equilibrium state and sends a "stability" trigger signal to the data synchronization and recording unit. This determination method based on quantitative indicators replaces the traditional manual operation method that relies on subjective experience and observation, ensuring the objectivity and consistency of data acquisition.

[0034] The data synchronization and recording unit is responsible for establishing a precise time and data link. Upon receiving a "stable" trigger signal from the system status identification unit, this unit synchronously latches the current absolute coordinate readings of the two-axis grating scales, the internal high-precision timestamp, and the measurement readings of the plumb line coordinate instrument received via an external communication interface or input by the operator within the same system clock cycle. This external communication interface can be RS-485, Ethernet, or a wireless communication module, used for direct communication with the host computer or data acquisition unit of the dam safety monitoring system to achieve automatic acquisition of plumb line coordinate instrument readings. All this correlated data is packaged into a complete test record and stored in the controller's built-in non-volatile memory.

[0035] According to a second embodiment of the present invention, referring to Figure 2 This invention claims protection for an automated and precise wire-pulling test method for a plumb line monitoring system, comprising the following steps: The device is installed and initialized by installing the automated precision line-pulling test device for the positive and negative plumb line monitoring system near the plumb line coordinate instrument to be tested, and then powering on the device for initialization and adjusting its horizontal attitude. Automatic centering and micro-force clamping: The motion execution module of the control device moves the end effector module to the vicinity of the vertical line, and further controls the end effector module to perform stable constant force clamping on the vertical line with a preset micro-target clamping force; Once the reference zero point is established, after clamping is completed and the vertical system is waited for to reach static equilibrium, the absolute coordinate value measured by the displacement measurement module at this moment is recorded and defined as the reference zero point of the test sequence. The automated multi-point toggle test sequence automatically and cyclically drives the end effector module to precisely position itself at the target location for each preset target test point, waits for the vertical system to enter a new static equilibrium state, and simultaneously collects and records the actual coordinate readings of the current device and the readings of the measured vertical coordinate instrument. Coordinate system relationship identification and data correction: After completing at least three non-collinear test points, the changes in multiple sets of device coordinate readings and the measured coordinate instrument readings are used to establish and solve an affine transformation model between coordinate systems. This model is then used to correct the test data to eliminate alignment errors generated during device installation.

[0036] Furthermore, referring to Figure 3 The automatic centering and micro-force clamping steps specifically include: The Z-axis micro-feed unit within the end effector module is controlled to drive the micro-force gripper unit to approach the vertical line at a preset, extremely low speed. The output signal of the force sensor in the micro-force gripper unit is continuously monitored. When the force value exceeds the preset contact threshold, the feeding of the Z-axis micro-motion feed unit is stopped immediately. The constant force clamping program is started, and the current of the voice coil motor that drives the opening and closing of the micro-force gripper unit is controlled in a closed loop to make the actual clamping force applied to the vertical line accurately and stably stabilized at the preset target force value.

[0037] Furthermore, referring to Figure 4 The waiting step in the automated multi-point toggle test sequence sub-step for the vertical line system to enter a new static equilibrium state is implemented through a vertical line stability determination algorithm, including: After the positioning motion is completed, a sequence of minute position fluctuation data output by the displacement measurement module is continuously collected at a high sampling rate; Online spectral analysis is performed on the position fluctuation data sequence to calculate the power spectral density of the position signal within the natural vibration frequency range of the vertical line; The power spectral density is compared with a preset stability threshold. When the power spectral density is lower than the stability threshold for several consecutive time windows, it is determined that the vertical system has reached a static equilibrium state.

[0038] Furthermore, the method also includes a test result evaluation and report generation step, which includes: Using the identified transformation matrix M and offset vector O, the displacement readings applied by the device in each test are transformed into a coordinate system aligned with the measured vertical coordinate instrument to obtain the corrected true applied displacement value. The corrected actual applied displacement value is compared one-to-one with the reading change value of the measured vertical coordinate instrument to calculate the key performance indicators of the coordinate instrument, such as linearity error, indication error, repeatability, and inter-axis coupling, and a calibration report is generated.

[0039] In this embodiment, the specific steps include: Step 1: Device Installation and Initialization. Move the device laterally close to the plumb line, ensuring the C-shaped frame opening accommodates the plumb line. Attach the magnetic mounting feet to appropriate positions on the plumb line coordinate instrument panel. Referencing the readings from the integrated dual-axis tilt sensors, the operator adjusts the height of each foot to ensure the device base is level. Power on the device; the control system executes a self-test program and drives the X and Y axis motion units back to their respective mechanical origins or absolute encoder zero points.

[0040] The second step is automatic centering and micro-force clamping. The operator issues commands through the human-machine interface, or the device automatically identifies the approximate position of the vertical line using its built-in vision sensor. The controller drives the motion execution module to move the end effector near the vertical line. Then, the Z-axis piezoelectric actuator is activated, causing the gripper to approach the vertical line at an extremely low speed. During this process, the force sensor continuously monitors the contact force; once the detected force exceeds a set micro-threshold, the Z-axis feed immediately stops. Subsequently, the controller executes a constant-force clamping program, using a voice coil motor in closed-loop control to clamp the vertical line with a preset, extremely small target force value.

[0041] The third step is to establish the reference zero point. After clamping is completed, the controller activates the vertical stability determination algorithm. After the algorithm determines that the vertical system has reached static equilibrium, the controller records the absolute coordinate values ​​(X0, Y0) measured by the X-axis and Y-axis grating scale system at this moment and defines them as the reference zero point or absolute reference origin for this complete test sequence.

[0042] The fourth step is the automated multi-point displacement test sequence. The operator inputs the coordinates of one or more test points through a human-machine interface. These coordinates are the target displacement vectors (ΔX_dam, ΔY_dam) defined in an ideal dam coordinate system. For each test point in the sequence, the controller executes the following sub-steps: Sub-step one: Coordinate transformation and trajectory generation. The controller uses an internally stored coordinate transformation matrix, initially set to an identity matrix, to transform the displacement vector in the target dam coordinate system into the device's own coordinate system, and calculates the target position (X_target, Y_target) accordingly. Subsequently, the trajectory planner generates a smooth S-shaped trajectory from the current position to the target position.

[0043] Sub-step two: Precise positioning and stabilization waiting. The motion control unit drives the servo motor to move the end effector to the target position strictly according to the generated trajectory. After positioning is completed, the vertical stability determination algorithm is called again to wait for and confirm that the vertical line has entered a new static equilibrium state.

[0044] Sub-step three: Synchronous data acquisition. Once the system is stable, the data synchronization and recording unit immediately performs a data latching operation, recording the actual grating ruler readings (X_actual, Y_actual) and high-precision timestamps in the current device coordinate system, and simultaneously triggering the acquisition of the vertical coordinate instrument readings (X_sensor, Y_sensor).

[0045] Sub-step four: Precise reset. After data acquisition is complete, the controller drives the end effector to precisely return to the previously established reference zero point (X0, Y0) along a smooth trajectory, and waits for the system to stabilize again, preparing for the execution of the next test point.

[0046] Coordinate system relationship identification and data correction. After completing tests at at least three non-collinear test points, the controller or the accompanying host computer software executes the coordinate system relationship identification algorithm. This algorithm uses multiple sets of device coordinate reading vectors P_device = (X_actual – X0, Y_actual – Y0) with applied displacement and their corresponding change vectors of the measured coordinate instrument readings ΔP_sensor = (X_sensor - X_sensor_initial, Y_sensor - Y_sensor_initial) to establish and solve an affine transformation model: P_device = M * ΔP_sensor + O. Here, M is a 2x2 transformation matrix containing the rotation angles and scaling factors for both axes due to device installation; O is a 2x1 offset vector. After obtaining the optimal estimates of matrix M and vector O using the least squares method, the transformation relationship is established. Using this identified transformation relationship, any precise displacement applied in the device coordinate system can be accurately converted to the dam coordinate system aligned with the plumb line coordinate instrument, thereby eliminating the unavoidable alignment error during device installation and obtaining the true displacement value applied to the vertical line in the dam coordinate system during each adjustment test.

[0047] Test result evaluation and report generation. The actual applied displacement values ​​of all test points after coordinate system correction are compared one-to-one with the reading changes of the vertical coordinate instrument. The key performance indicators of the coordinate instrument in each axis, such as linearity error, indication error, repeatability, and inter-axis coupling, are calculated, and finally a quantitative and comprehensive calibration report is generated.

[0048] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0049] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units described above can be implemented in hardware or as software functional units. The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

[0050] The specific embodiments of the invention have been described in detail above, but they are only examples, and this application is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the invention are also within the scope of this application. Therefore, all equivalent changes, modifications, and improvements made without departing from the spirit and principles of this application should be covered within the scope of this application.

Claims

1. An automated precision line test device for a positive and negative drop line monitoring system, comprising: Comprise: a base module for stably fixing the device to the surface of the vertical coordinate instrument to be tested or its adjacent fixed structure; a motion execution module installed on the base module and configured to enable precise translational motion in a two-dimensional orthogonal coordinate system; an end effector module arranged on the moving component of the motion execution module for clamping and releasing the plumb line with controlled force; a displacement measurement module for measuring the absolute position coordinates of the end effector module in the two-dimensional orthogonal coordinate system in real time; a control and data processing module electrically connected and in data communication with the motion execution module, end effector module and displacement measurement module, respectively, for accurately controlling the displacement output of the motion execution module and synchronously collecting the position feedback data of the displacement measurement module according to the preset test procedure.

2. The automated precision pole testing device for a positive and negative pole monitoring system of claim 1, wherein, The base module comprises: a rigid frame body with a C-shaped or U-shaped geometric configuration, the opening of the frame body being configured to allow the device to be installed from the side of the plumb line without detaching the plumb line from its upper and lower fixed ends; at least three magnetically fixed feet with adjustable height arranged at the bottom of the frame body, each of the magnetically fixed feet being internally provided with a permanent magnet for attracting the device to a ferromagnetic surface by magnetic force, and the height adjustment mechanism of the feet being used for accurately adjusting the initial horizontal attitude of the device; a dual-axis digital inclination sensor integrated on the base module, the inclination sensor being electrically connected with the control and data processing module for outputting the pitch angle and roll angle data of the device in real time to assist the adjustment of the initial horizontal attitude or for parameter input of the coordinate conversion algorithm.

3. The automated precision line testing device for a positive and negative drop line monitoring system of claim 1, wherein, The motion execution module is composed of orthogonal superposition of X-direction linear motion unit and Y-direction linear motion unit, each of the linear motion units comprising: a fixed guide rail base; a sliding table for linear reciprocating motion along the guide rail base; a pre-tightening rolling guide rail pair for realizing high rigidity and smooth motion between the guide rail base and the sliding table; a driving mechanism composed of brushless DC servo motor, high-precision ball screw pair and zero-backlash shaft coupling for driving the sliding table to move; The displacement measurement module is a direct measurement system independent of the driving mechanism of the motion execution module, which specifically comprises X-direction linear displacement sensor and Y-direction linear displacement sensor respectively installed between the fixed guide rail base and the moving sliding table of the X-direction linear motion unit and the Y-direction linear motion unit; the linear displacement sensor is a grating ruler system or a magnetic grating ruler system.

4. The automated precision pole testing device for a positive and negative pole monitoring system of claim 3, wherein, The grating ruler system comprises a fixed ruler grating and a reading head moving with the sliding table; the ruler grating is an absolute encoding grating ruler with low thermal expansion coefficient base material, which can provide absolute position information as soon as it is powered on; and the installation position of the reading head follows the Abbe principle, so that its measurement axis is collinear or parallel to the action point of the end effector module clamping the plumb line in space and is closest to it; The end effector module comprises: A Z-direction micro-feeding unit is configured to drive the clamping component to slowly and gently approach the plumb line after the motion execution module completes the two-dimensional planar positioning. A micro-force gripper unit is mounted on the Z-direction micro-feeding unit and is configured to perform clamping and releasing operations on the plumb line.

5. The automated precision line testing device for a positive and negative drop line monitoring system of claim 4, wherein, The micro-force gripper unit adopts a parallel double-finger structure, and each of the two clamping fingers is provided with a pair of V-shaped notched micro-rollers that can rotate freely. The V-shaped notched micro-rollers are configured to automatically position the plumb line to the center of the V-shaped notch during clamping, and the rotatable feature of the rollers is used to avoid generating sliding friction and torsional stress on the surface of the plumb line during clamping.

6. The apparatus of claim 1, wherein, The opening and closing movement of the micro-force gripper unit is driven by a voice coil motor, and a micro-force sensor is integrated in the transmission chain of the voice coil motor. The control and data processing module performs closed-loop control on the driving current of the voice coil motor based on the real-time feedback signal of the micro-force sensor to achieve constant force clamping of the plumb line. The control software running inside the control and data processing module includes: A multi-axis motion control unit includes a trajectory planner adopting an S-shaped acceleration and deceleration curve algorithm to generate a smooth motion trajectory to suppress mechanical impact and vibration, and the feedback signal of the position control loop is directly derived from the displacement measurement module to constitute a full-closed-loop control.

7. An automated precision line test method for a positive and negative drop line monitoring system, comprising: A system state recognition unit includes a plumb line stable state judgment algorithm module to objectively determine whether the plumb line has returned to a static equilibrium state by performing frequency spectrum analysis on the high-frequency sampled position data of the displacement measurement module based on a preset stable threshold after the positioning motion is completed; and A data synchronization and recording unit synchronously latches the absolute coordinate reading measured by the displacement measurement module, the internal high-precision time stamp, and the measurement reading of the plumb line coordinate instrument obtained through the external communication interface in the same system clock cycle after receiving the stable trigger signal sent by the system state recognition unit. The method comprises the following steps: Device installation and initialization: install the device as claimed in any one of claims 1 to 6 near the plumb line coordinate instrument to be tested, and perform power-on initialization and horizontal posture adjustment on the device; Automatic centering and micro-force clamping: control the motion execution module of the device to move the end effector module to the vicinity of the plumb line, and further control the end effector module to stably clamp the plumb line with a preset small target clamping force; Reference zero point establishment: after clamping is completed and the plumb line system reaches a static equilibrium state, record the absolute coordinate value measured by the displacement measurement module at this moment, and define it as the reference zero point of the test sequence; Automatic multi-point pulling test sequence: for each preset target test point, automatically execute the following sub-steps in a cycle: drive the end effector module to precisely position to the target position, wait for the plumb line system to enter a new static equilibrium state, and synchronously collect and record the actual coordinate reading of the device and the reading of the measured plumb line coordinate instrument; and Coordinate system relationship identification and data correction: after at least three non-collinear test points are completed, the change in the collected multiple sets of device coordinate readings and the measured coordinate instrument readings is used to establish and solve an affine transformation model between the coordinate systems, and the model is used to correct the test data to eliminate alignment errors caused by device installation.

8. The method of claim 7, wherein, The automatic centering and micro-force clamping step specifically includes: Controlling the Z-direction micro-motion feeding unit in the end effector module to drive the micro-force clamping jaw unit to approach the plumb line at a preset extremely low speed; Continuously monitoring the output signal of the force sensor in the micro-force clamping jaw unit, and immediately stopping the feeding of the Z-direction micro-motion feeding unit when a force value exceeding a preset contact threshold is detected; Starting a constant force clamping program to accurately stabilize the actual clamping force applied to the plumb line at a preset target force value by closed-loop control of the current of the voice coil motor driving the micro-force clamping jaw unit to open and close.

9. The method of claim 8, wherein, The waiting for the plumb line system to enter a new static equilibrium state in the automatic multi-point dialing test sequence sub-step is achieved by a plumb line stable state judgment algorithm, which includes: After the positioning motion is completed, continuously collecting the small position fluctuation data sequence output by the displacement measurement module at a high sampling rate; Performing online spectral analysis on the position fluctuation data sequence to calculate the power spectral density of the position signal in the plumb line inherent vibration frequency range; Comparing the power spectral density with a preset stability threshold, and when the power spectral density is continuously lower than the stability threshold in several time windows, it is determined that the plumb line system has reached a static equilibrium state.

10. The method of claim 9, wherein, It also includes a test result evaluation and report generation step, which includes: Using the identified transformation matrix M and offset vector O, converting the displacement readings applied by the device in each test to the coordinate system aligned with the measured plumb line coordinate instrument to obtain the corrected true applied displacement value; Comparing the corrected true applied displacement value with the reading change value of the measured plumb line coordinate instrument one by one to calculate the key performance indicators of the coordinate instrument, such as linearity error, indication error, repeatability, and inter-axis coupling, and generate a test and calibration report.

Images