An automated ultrasonic testing system for large castings

Abstract

The application relates to the technical field of automatic nondestructive testing, in particular to an automatic ultrasonic detection system for large castings, which comprises the following modules: an acoustic coupling quantification module: through the collected real-time interface wave amplitude and stability indexes, a real-time acoustic coupling quality index is generated; a speed modulation decision module: according to the coupling quality index and a preset threshold value, a speed scaling coefficient is generated; a scanning speed generation module: combining the speed scaling coefficient and a basic scanning speed, an instantaneous scanning speed instruction is generated; a coupling recovery control module: when the speed scaling coefficient is zero, a micro-motion strategy is triggered to recover the coupling; the application converts the ultrasonic signal into a quality index to dynamically modulate the scanning speed by establishing an acoustic coupling quantification model, realizes real-time coupling of physical perception and motion control, overcomes the defect that data loss is caused by the fact that traditional fixed-speed scanning cannot perceive surface obstacles, and ensures the detection reliability on complex surfaces.

Description

Technical Field

[0001] This invention relates to the field of automated nondestructive testing technology, specifically to an automated ultrasonic testing system for large castings. Background Technology

[0002] In current applications of automated ultrasonic testing for large castings, a fixed working mode of offline path planning and execution is commonly used. In this mode, the industrial robot strictly follows a pre-set trajectory and constant speed to scan, and does not have the ability to perceive and respond to the physical state in real time during the testing process.

[0003] While this solution offers a certain level of automation on ideal workpieces with smooth and flat surfaces, its inherent defects are particularly pronounced for large castings with random acoustic obstacles such as oxide scale, residual molding sand, and uneven coatings. A constant scanning speed cannot adapt to localized and transient surface acoustic characteristics; when the probe passes through an obstacle area, acoustic coupling failure is highly likely, resulting in the permanent loss of critical detection data. To mitigate the risk of coupling failure, operators are often forced to run the entire system at a conservative scanning speed far below the ideal value, leading to extremely low overall detection efficiency. Existing automated systems lack quantitative assessment and proactive recovery mechanisms for coupling states; once coupling is interrupted, manual intervention is often required, severely diminishing the value of automation.

[0004] Therefore, how to establish an adaptive scanning method that can couple physical perception and motion control in real time to resolve the technical contradiction between detection efficiency and coupling reliability in fixed scanning mode has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an automated ultrasonic testing system for large castings. Specifically, the technical solution of this invention includes:

[0006] The acoustic coupling quantization module is used to acquire ultrasonic signals in real time to obtain the real-time interface wave amplitude, and combine the real-time interface wave amplitude, the preset reference interface wave amplitude, the real-time calculated interface wave amplitude stability index, and the preset maximum allowable amplitude standard deviation to generate the real-time acoustic coupling quality index.

[0007] The velocity modulation decision module is used to generate a velocity scaling factor based on the real-time acoustic coupling quality index generated by the acoustic coupling quantization module and based on a preset coupling failure judgment threshold and a high coupling quality threshold.

[0008] The scan speed generation module is used to combine the speed scaling coefficient generated by the speed modulation decision module with a preset base scan speed to generate an instantaneous scan speed command.

[0009] The coupling recovery control module is used to trigger a preset acoustic coupling recovery micro-motion strategy in response to an event that the speed scaling factor generated by the speed modulation decision module is zero, and to terminate the micro-motion strategy when the real-time acoustic coupling quality index generated by the acoustic coupling quantization module recovers to above the coupling failure judgment threshold.

[0010] Preferably, the speed modulation decision module generates the speed scaling factor, including:

[0011] If the real-time acoustic coupling quality index is not lower than the high coupling quality threshold, then the velocity scaling factor is determined to be a preset maximum value;

[0012] If the real-time acoustic coupling quality index is lower than the high coupling quality threshold but not lower than the coupling failure determination threshold, then the velocity scaling factor is calculated based on the real-time acoustic coupling quality index and the preset velocity attenuation index.

[0013] If the real-time acoustic coupling quality index is lower than the coupling failure determination threshold, then the velocity scaling factor is set to zero.

[0014] Preferably, the interface wave amplitude stability index refers to the standard deviation of the real-time interface wave amplitude collected within a preset time window.

[0015] Preferably, the reference interface wave amplitude and the standard deviation of the maximum permissible amplitude are baseline values ​​obtained by performing a calibration procedure before the start of the detection task.

[0016] Preferably, the velocity decay index is a preset nonlinear adjustment constant that is adaptively selected based on the obstacle distribution characteristics on the surface of the casting to be tested.

[0017] Preferably, the coupling recovery control module is further configured to:

[0018] If the real-time acoustic coupling quality index fails to recover to above the coupling failure judgment threshold within the preset time or number of attempts, the current coordinates and surrounding area are marked as areas to be reviewed, and subsequent path scanning continues.

[0019] Preferably, the setting of the coupling failure determination threshold is determined based on the requirements of the minimum detectable defect signal-to-noise ratio in the non-destructive testing process standard.

[0020] Preferably, the acoustic coupling recovery micro-motion strategy involves controlling the detection system to execute a predefined search path near the current stopping point.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. This invention establishes an acoustic coupling quantization model to convert real-time ultrasonic signals from the physical world into a standardized quality index, and uses this as a basis to dynamically modulate the scanning speed of the robot. This overcomes the defects of coupling failure and data loss caused by the inability to perceive surface obstacles in the traditional fixed-speed scanning mode. Through adaptive control of real-time coupling, it ensures the continuity and reliability of data in the process of detecting complex surfaces.

[0023] 2. This invention employs a piecewise, nonlinear speed modulation decision logic, which can maintain maximum efficiency when the coupling quality is good, smoothly decelerate to attempt adaptive recovery when the quality slightly deteriorates, and only stop when there is a complete failure. Compared with conservative low-speed scanning or simple threshold emergency stop, this invention maximizes scanning efficiency while ensuring detection reliability, and avoids unnecessary emergency stops and frequent acceleration and deceleration, thus improving the stability and smoothness of automated scanning.

[0024] 3. This invention dynamically sets the reference benchmark through a mandatory pre-task calibration procedure, eliminating systematic errors introduced by differences in equipment or workpieces, and greatly enhancing the system's adaptability to different testing environments. At the same time, it directly links the core coupling failure judgment threshold with the signal-to-noise ratio requirements in industry non-destructive testing process standards, ensuring that while pursuing efficiency, the validity of the system's test results strictly adheres to industry standards, thus solving the core pain point of automated systems.

[0025] 4. This invention integrates an acoustic coupling recovery micro-motion strategy and an anomaly handling process after recovery failure. When coupling is interrupted, the system can actively attempt to restore coupling through micro-motion search, significantly reducing manual intervention. If recovery fails, the system automatically marks the area to be reviewed and continues subsequent tasks, avoiding interruption of the entire automated process due to local faults. This design greatly improves the robustness and intelligence level of the entire automated inspection process for large castings. Attached Figure Description

[0026] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0027] Figure 1 This is a structural diagram of the system of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. Example 1:

[0029] Please see Figure 1 An automated ultrasonic testing system for large castings includes:

[0030] The acoustic coupling quantization module is used to acquire ultrasonic signals in real time to obtain the real-time interface wave amplitude, and combine the real-time interface wave amplitude, the preset reference interface wave amplitude, the real-time calculated interface wave amplitude stability index, and the preset maximum allowable amplitude standard deviation to generate the real-time acoustic coupling quality index.

[0031] The velocity modulation decision module is used to generate a velocity scaling factor based on the real-time acoustic coupling quality index generated by the acoustic coupling quantization module and based on the preset coupling failure judgment threshold and high coupling quality threshold.

[0032] The scan speed generation module is used to combine the speed scaling factor generated by the speed modulation decision module with the preset base scan speed to generate an instantaneous scan speed command.

[0033] The coupling recovery control module is used to trigger a preset acoustic coupling recovery micro-motion strategy in response to an event where the speed scaling factor generated by the speed modulation decision module is zero, and to terminate the micro-motion strategy when the real-time acoustic coupling quality index generated by the acoustic coupling quantization module recovers to above the coupling failure judgment threshold.

[0034] This embodiment provides an automated ultrasonic testing system for large castings. The system aims to address the inherent limitations of traditional offline path planning and fixed-mode execution, which are unable to cope with random acoustic obstacles such as oxide scale and residual molding sand commonly found on the surface of large castings, leading to acoustic coupling failure and loss of testing data. This invention establishes a novel adaptive scanning method based on real-time acoustic characteristics. By deeply coupling robot motion control with ultrasonic physical sensing in real time, the system can intelligently adapt to local and transient surface acoustic characteristics, thereby resolving the technical contradiction between testing efficiency and coupling reliability.

[0035] In this embodiment, the automated ultrasonic testing system includes an acoustic coupling quantization module, a velocity modulation decision module, a scan velocity generation module, and a coupling recovery control module.

[0036] The acoustic coupling quantization module aims to transform real-time acquired, physical-level ultrasound signals into a standardized mathematical index that can be used for advanced control decisions. This module is used to achieve signal conversion and quantization from physical sensing to digital control. In this embodiment, the module extracts the real-time interface wave amplitude from real-time acquired ultrasound A-scan signals. And combined with a preset reference value, namely the amplitude of the reference interface wave. And the quantification of coupling stability, i.e., the interface wave amplitude stability index. and the standard deviation of the maximum permissible amplitude To jointly calculate and generate a real-time acoustic coupling quality index To achieve the above objectives, this embodiment constructs a measurement model, the mathematical form of which is as follows:

[0037] ;

[0038] in, The real-time acoustic coupling quality index (RCI) is a quantitative score of the acoustic coupling state between the probe and the casting surface at the current moment. Its purpose is to provide a direct, dimensionless decision-making basis for subsequent velocity control; it is a range... The scalar values ​​between these are derived from real-time calculations by this module based on the following parameters;

[0039] Real-time interface wave amplitude refers to the amplitude of the echo signal generated by the interface between the probe and the surface of the casting in the current ultrasonic A-scan signal. Its function is to directly reflect the acoustic energy transmission efficiency of the coupling interface; it is obtained by real-time measurement by the ultrasonic signal acquisition hardware of the system.

[0040] The reference interface wave amplitude refers to the baseline value of the interface wave amplitude measured under ideal coupling conditions. Its function is to provide a reference for... It provides a standardized, dimensionless reference; its source is a reference value obtained through a mandatory calibration procedure before the start of the testing task.

[0041] Interface wave amplitude stability index refers to the stability of the wave amplitude within a very short recent time window. Inside, a series of measurements were obtained The standard deviation of the value quantifies the jitter of the coupling state; its source is based on historical data from this module. The data was calculated.

[0042] The maximum permissible standard deviation refers to the deviation from the standard deviation of the maximum permissible range. The corresponding stability benchmark represents the critical fluctuation level of the coupling state from stability to unacceptable; its source is also set through the calibration procedure.

[0043] Using this formula, the acoustic coupling quantization module transforms complex physical phenomena into a single, intuitive quality index. It is then continuously output to the speed modulation decision module;

[0044] The speed modulation decision module aims to dynamically and intelligently determine a scanning speed adjustment strategy adapted to the current state based on the real-time quality of acoustic coupling. In this embodiment, the module receives the real-time acoustic coupling quality index generated by the acoustic coupling quantization module. As input, and based on two preset key thresholds, namely the coupling failure determination threshold. With high coupling quality threshold To generate a speed scaling factor This coefficient constitutes the decision-making link from coupling quality perception to scanning behavior regulation;

[0045] The scanning velocity generation module aims to perform the final motion command calculation, transforming the abstract decisions of the upper-level modules into specific velocity commands that the robot controller can directly execute. In this embodiment, this module uses the dimensionless velocity scaling coefficient generated by the velocity modulation decision module. With a user-preset base scan speed By combining these, an instantaneous scan speed command is generated. Its calculation logic is as follows:

[0046] ;

[0047] in, Instantaneous scan velocity command refers to the real-time velocity vector that the system ultimately outputs to the robot motion control module. Its function is to achieve precise and dynamic control of the robot's motion; its source is the calculation result of this module.

[0048] The base scan speed refers to the highest scan speed vector that the user expects to achieve under ideal coupling conditions. Its direction is along the basic path planned offline; it is derived from the user's pre-set parameters based on process requirements.

[0049] The speed scaling factor refers to the factor generated by the speed modulation decision module, and its range is within... The dimensionless scalar between these two values ​​serves to dynamically modulate the base velocity; its source is the output of the velocity modulation decision module.

[0050] The coupling recovery control module aims to handle extreme coupling failure situations, ensuring that the system does not lose data when encountering severe obstacles and possesses a certain degree of autonomous recovery capability, thereby guaranteeing the robustness of the entire detection process. In this embodiment, the module continuously monitors the velocity scaling coefficient generated by the velocity modulation decision module. When the coefficient becomes zero, it indicates a severe coupling failure, at which point the module immediately triggers a preset acoustic coupling recovery micro-motion strategy. During the execution of this strategy, the acoustic coupling quantization module continues to calculate... ;once Restored to the coupling failure determination threshold In this way, the coupling recovery control module terminates the micro-motion strategy, and the system resumes normal scanning;

[0051] This invention constructs a complete closed loop of perception, decision-making, and control through the coordinated work of the four modules mentioned above. It integrates ultrasonic physical perception with robot motion control in real time and in depth, enabling the automated inspection system to evolve from a blind path executor into an intelligent agent with local surface state perception and adaptive capabilities. This fundamentally solves the contradiction in the prior art where inspection efficiency must be sacrificed to ensure coupling reliability, thereby maximizing the overall efficiency and robustness of automated ultrasonic inspection of large castings without reducing inspection reliability.

[0052] Implement Column 2:

[0053] The velocity modulation decision module generates velocity scaling factors, including:

[0054] If the real-time acoustic coupling quality index is not lower than the high coupling quality threshold, the velocity scaling factor is set to the preset maximum value.

[0055] If the real-time acoustic coupling quality index is lower than the high coupling quality threshold but not lower than the coupling failure judgment threshold, the velocity scaling factor is calculated based on the real-time acoustic coupling quality index and the preset velocity attenuation index.

[0056] If the real-time acoustic coupling quality index is lower than the coupling failure judgment threshold, the velocity scaling factor is set to zero.

[0057] This embodiment, based on Embodiment 1, provides a more detailed implementation of the speed modulation decision module. To achieve differentiated response strategies under different coupling states—namely, maintaining high speed when coupling is good, smoothly reducing speed during slight drops, and stopping immediately in the event of severe failure—this embodiment generates a speed scaling factor. The decision logic is designed as a piecewise function; this function takes the input real-time acoustic coupling quality index as an example. It is divided into three intervals, each corresponding to a different calculation method:

[0058] ;

[0059] The underlying logic is as follows:

[0060] If the real-time acoustic coupling quality index Not lower than the high coupling quality threshold Then the speed scaling factor is set to the preset maximum value of 1; high coupling quality threshold This refers to a threshold used to define the optimal coupling state, derived from an empirical value set after balancing detection efficiency and system stability; for example, it might be set to 0.9. This value is designed to ensure that full-speed scanning is only performed when acoustic coupling is close to ideal, avoiding frequent speed adjustments due to minor fluctuations, thus guaranteeing the stability of high-speed operation. This corresponds to the ideal condition of a smooth casting surface and sufficient coupling agent, with the system operating at 100% of its base speed. Perform the most efficient scan;

[0061] If the real-time acoustic coupling quality index Below the high coupling quality threshold And not lower than the coupling failure judgment threshold Then according to and the preset speed decay index The speed scaling factor is calculated using parameters; this calculation method achieves a smooth, non-linear transition of speed from 1 to 0 through a normalization and exponentialization process; for example, in a task instance, setting... It is 150mm / s. , , When the probe encounters a small amount of residual sand, When it drops to 0.6, Instantaneous velocity Automatically adjusted to This proactive and smooth deceleration creates conditions for the re-penetration of the coupling agent, thus allowing for the restoration of coupling and avoiding sudden stops caused by minor fluctuations, thereby improving the smoothness of the scan.

[0062] If the real-time acoustic coupling quality index Below the coupling failure threshold If the speed scaling factor is zero, then the speed scaling factor is set to zero; this situation corresponds to the probe encountering severe obstacles such as thick oxide scale, resulting in complete coupling failure; the system will then calculate the instantaneous speed. When the value drops to 0, the robot immediately stops moving forward, thus fundamentally eliminating the risk of data omission.

[0063] Through this segmented, nonlinear speed modulation decision logic, the present invention achieves a refined and differentiated response to changes in coupling quality at different levels. Compared with simple linear control or threshold switching control, this scheme ensures absolute stopping when coupling fails, while making smooth and gradual adaptive adjustments to fluctuations in coupling quality. This avoids unnecessary sudden stops and frequent acceleration and deceleration, greatly improving the stability and smoothness of the automated scanning process, thereby further optimizing detection efficiency while ensuring quality.

[0064] Implement column 3:

[0065] The interface wave amplitude stability index refers to the standard deviation of the real-time interface wave amplitude collected within a preset time window.

[0066] The reference interface wave amplitude and the standard deviation of the maximum permissible amplitude are baseline values ​​obtained by performing a calibration procedure before the start of the testing task;

[0067] This embodiment, based on Embodiment 1, further explains the specific definitions and acquisition methods of key parameters in the acoustic coupling quantization module, aiming to ensure the accuracy, stability, and repeatability of the quantization results of this module;

[0068] Interface wave amplitude stability index The purpose is to introduce a time dimension into the evaluation of coupling quality, in order to distinguish between the two physical states of stable weak coupling and unstable coupling; in this embodiment, It is precisely defined as: within a preset, extremely short time window Inside, a series of real-time interface wave amplitudes were continuously collected. The standard deviation of the value; this design is based on the following technical considerations: a physically stable contact, even with low sound energy transmittance, its The value should also be relatively constant, therefore its standard deviation... It will be very small; conversely, a jittery, unstable contact will lead to... The value jumped drastically, causing its standard deviation to... Significantly increased; therefore, Introduced as a penalty item The calculation can more accurately reflect the true physical state of the coupling;

[0069] Reference interface wave amplitude Standard deviation of maximum permissible amplitude Its purpose is to provide and These two real-time variables provide an objective and consistent evaluation benchmark, eliminating systematic errors introduced by differences in probe model, equipment gain settings, or materials under test. In this embodiment, the source of these two parameters is strictly defined as: benchmark values ​​obtained by performing a mandatory calibration procedure before the start of the testing task. To further clarify the calibration process, the specific steps are as follows: placing the probe on a standard test block with known acoustic characteristics, and under ideal coupling conditions, continuously acquiring a set of interface wave amplitude samples within the calibration time window. ,in Based on this calibration dataset, the amplitude of the reference interface wave is... It is determined to be the mean of this sample group, i.e. Meanwhile, the maximum permissible standard deviation of the amplitude. Then based on the standard deviation of this group of samples And combined with the preset process tolerance coefficient To determine, for example, to set as Or one with Relevant experience points, such as ;

[0070] Through the The precise definition and the , The standardized acquisition method specified in this invention, together with other technologies, improves the accuracy and robustness of the acoustic coupling quantization module; The introduction of this feature allows the quantization model to focus not only on the strength of coupling but also on its stability, resulting in a more comprehensive evaluation dimension. Meanwhile, the mandatory calibration procedure ensures that the decision-making benchmark of the entire adaptive system is dynamically established based on the actual working conditions of the current task, rather than relying on fixed theoretical values. This greatly enhances the adaptability and reliability of the invention under different detection environments.

[0071] Implement Column 4:

[0072] The velocity decay index is a preset nonlinear adjustment constant that is adaptively selected based on the obstacle distribution characteristics on the surface of the casting to be tested.

[0073] The threshold for determining coupling failure is set based on the requirements for the minimum signal-to-noise ratio of detectable defects in the non-destructive testing process standards.

[0074] This embodiment, based on embodiment 2, includes a velocity attenuation index in the velocity modulation decision module. and coupling failure determination threshold Further explanation of the basis and technical implications of setting the two core control parameters;

[0075] Speed ​​decay index The purpose is to provide a means to adjust the nonlinearity of the velocity decay curve to adapt to the obstacle distribution characteristics on the surface of different castings under test; in this embodiment, It is a preset nonlinear adjustment constant that is adaptively selected based on the on-site working conditions; it is a dimensionless value greater than 0. Its technical considerations are as follows:

[0076] When the obstacles on the surface of the casting exhibit a fragmented but dense characteristic, a smaller one should be selected. Value; this makes the velocity decay curve in The value exhibits a large slope as soon as it begins to decrease, achieving a sensitive and rapid deceleration response;

[0077] When obstacles are large but sparsely distributed, a larger one can be selected. This value allows the system to maintain a high speed when dealing with minor coupling fluctuations, only when... Only during severe declines should a sharp deceleration be initiated to avoid overreaction;

[0078] Coupling failure determination threshold Its purpose is to establish a basic criterion for ensuring the validity of detection data in the entire adaptive scanning system; in this embodiment, The setting is not based on arbitrary empirical choices, but rather on the requirements for the minimum detectable defect signal-to-noise ratio in nondestructive testing process standards; specifically, those skilled in the art can establish this through process experiments. The correspondence between the value and the signal-to-noise ratio of the minimum detectable defect echo in the actual detection signal; for example, if the process standard requires a signal-to-noise ratio of not less than 6dB, then the minimum coupling state that just meets this requirement can be used as the reference value. The value is set to ;

[0079] The introduction of these two subordinate features enables the adaptive control model of this invention to possess configurability and compliance. Its configurability allows the system to be optimized for different workpiece surface characteristics, achieving flexible adaptation and finding the optimal balance between efficiency and stability in various scenarios; The strong correlation with testing process standards ensures that while pursuing automation efficiency, the validity and reliability of the test results strictly adhere to industry standards, thus solving the core pain point that automated systems may sacrifice testing quality in pursuit of speed.

[0080] Implementation List 5:

[0081] The coupling recovery control module is also used for:

[0082] If the real-time acoustic coupling quality index fails to recover to above the coupling failure judgment threshold within the preset time or number of attempts, the current coordinates and surrounding area will be marked as the area to be reviewed, and subsequent path scanning will continue.

[0083] The acoustic coupling recovery micro-motion strategy controls the detection system to execute a predefined search path near the current stopping point;

[0084] Based on Example 1, this embodiment further refines and improves the functionality of the coupling recovery control module, aiming to build a complete fault handling mechanism that can actively attempt recovery and ensure process continuity when recovery fails.

[0085] The acoustic coupling recovery micro-motion strategy aims to automatically perform local exploration to attempt to re-establish effective acoustic coupling when the system stops due to complete coupling failure. In this embodiment, the strategy specifically involves controlling the end effector to execute a predefined, minute search path, such as a cross-shaped or spiral trajectory, near the robot's current stopping point. Simultaneously, the acoustic coupling quantization module continuously calculates... Value; once at a certain point in the micro-motion process, Value restored to The system then immediately exits the micro-motion strategy and resumes normal scanning;

[0086] Furthermore, to address the obstacle where even micro-motion strategies fail to restore coupling, the coupling restoration control module also executes a preset exception handling procedure. This procedure is triggered if the failure occurs within a preset time threshold or a preset maximum number of attempts. The value has still not recovered to The above settings for the time threshold and the maximum number of attempts are based on empirical assessments of the time required for coupling agent re-penetration and efficiency considerations to avoid excessive time spent at a single fault point. Once triggered, the system will perform the following two actions:

[0087] Mark the current point's coordinates and surrounding area as the area to be reviewed, and record them in the log file;

[0088] Abandon the recovery attempt at the current point and continue with the subsequent offline planned path scan;

[0089] By combining a proactive micro-motion recovery strategy with a comprehensive failure handling mechanism, this invention significantly improves the robustness and intelligence of the entire automated inspection process. The micro-motion strategy enables the system to autonomously recover from common temporary coupling failures, significantly reducing the number of times manual intervention is required. The marking and continuing mechanism ensures that a single or a few fault points that cannot be automatically recovered will not cause the interruption of the automated scanning task of the entire large casting, ensuring the integrity of the process. Ultimately, the system can autonomously complete the inspection of most areas and accurately record the areas that require manual review, maximizing the efficiency of human-machine collaboration.

[0090] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An automated ultrasonic testing system for large castings, characterized in that, include: The acoustic coupling quantization module is used to acquire ultrasonic signals in real time to obtain the real-time interface wave amplitude, and to generate a real-time acoustic coupling quality index by combining the real-time interface wave amplitude, a preset reference interface wave amplitude, a real-time calculated interface wave amplitude stability index, and a preset maximum allowable amplitude standard deviation. The interface wave amplitude stability index refers to the standard deviation of the real-time interface wave amplitude acquired within a preset time window. The formula for calculating the real-time acoustic coupling quality index is: ； in, The real-time acoustic coupling quality index refers to a quantitative score of the acoustic coupling state between the probe and the casting surface at the current moment. It is within the range scalars between; Real-time interface wave amplitude refers to the amplitude of the echo signal generated by the interface between the probe and the surface of the casting in the current ultrasonic A-scan signal. Reference interface wave amplitude refers to the baseline value of the interface wave amplitude measured under ideal coupling conditions. Interface wave amplitude stability index refers to the stability of the wave amplitude within a very short recent time window. Inside, a series of measurements were obtained Standard deviation of the value; The maximum permissible standard deviation refers to the standard deviation of the range. The corresponding stability benchmark; The velocity modulation decision module is used to generate a velocity scaling factor based on the real-time acoustic coupling quality index generated by the acoustic coupling quantization module and based on a preset coupling failure judgment threshold and a high coupling quality threshold. The setting of the coupling failure judgment threshold is determined according to the requirements of the minimum detectable defect signal-to-noise ratio in the non-destructive testing process standard. The high coupling quality threshold refers to a threshold used to define the optimal coupling state, which is derived from an empirical value set after balancing detection efficiency and system stability. If the real-time acoustic coupling quality index is lower than the coupling failure judgment threshold, the velocity scaling factor is set to zero. The scan speed generation module is used to combine the speed scaling coefficient generated by the speed modulation decision module with a preset base scan speed to generate an instantaneous scan speed command. The coupling recovery control module is used to trigger a preset acoustic coupling recovery micro-motion strategy in response to an event generated by the velocity modulation decision module that the velocity scaling factor is zero, and to terminate the micro-motion strategy when the real-time acoustic coupling quality index generated by the acoustic coupling quantization module recovers to above the coupling failure judgment threshold. The acoustic coupling recovery micro-motion strategy controls the detection system to execute a predefined search path near the current stopping point. While performing the micro-motion, the acoustic coupling quantization module continuously calculates... value.

2. The automated ultrasonic testing system for large castings according to claim 1, characterized in that, The speed modulation decision module generates speed scaling coefficients, including: If the real-time acoustic coupling quality index is not lower than the high coupling quality threshold, then the velocity scaling factor is set to a preset maximum value of 1. If the real-time acoustic coupling quality index is lower than the high coupling quality threshold but not lower than the coupling failure judgment threshold, then the velocity scaling factor is calculated based on the real-time acoustic coupling quality index and the preset velocity attenuation index; the velocity attenuation index is a preset nonlinear adjustment constant adaptively selected based on the obstacle distribution characteristics on the surface of the casting to be tested.

3. The automated ultrasonic testing system for large castings according to claim 1, characterized in that, The reference interface wave amplitude and the standard deviation of the maximum permissible amplitude are baseline values ​​obtained by performing a calibration procedure before the start of the detection task.

4. The automated ultrasonic testing system for large castings according to claim 1, characterized in that, The coupling recovery control module is also used for: If the real-time acoustic coupling quality index fails to recover to above the coupling failure judgment threshold within the preset time or number of attempts, the current coordinates and surrounding area are marked as areas to be reviewed, and subsequent path scanning continues.

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