A low-communication-load attack-resistant security control method for a high-temperature forging three-dimensional measurement system

Abstract

The application discloses a low-communication-load attack-resistant security control method for a high-temperature forging three-dimensional measurement system. The method is used for describing the multi-view image acquisition, stripe demodulation, three-dimensional reconstruction and parameter adjustment process of the high-temperature forging under the continuous-time Markov jump singularly perturbed system (MJSPSs) jointly acted by thermal radiation, strong reflection, local shielding, forging vibration and network attack. Firstly, a dynamic event triggering mechanism (DETM) is introduced to dynamically adjust the data transmission frequency to save network bandwidth. Secondly, a hybrid scheduling protocol (WTOD and RRP switching) is constructed in the multi-channel network environment of the high-temperature forging three-dimensional measurement to coordinate the sensor nodes and prevent denial of service (DoS) and deception attacks. Then, a hidden Markov model (HMM) framework is established to process the three-dimensional measurement working condition mode identification mismatch problem caused by network transmission, and an asynchronous observer is designed to estimate the unobservable state of the three-dimensional morphology of the high-temperature forging. Finally, an integral sliding surface and an asynchronous sliding mode parameter regulator are constructed based on the estimated state. The application effectively guarantees the random stability and hybrid and dissipation performance of the high-temperature forging three-dimensional measurement system under the joint action of high-temperature optical disturbance and complex network attack while reducing the consumption of communication resources.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional vision measurement and measurement system safety control technology for high-temperature forgings, and in particular to a low-communication-load anti-attack safety control method for conditions such as high-temperature thermal radiation, strong reflection, oxide scale interference, forging vibration and communication attacks. Background Technology

[0002] During the forming process of high-temperature forgings, it is necessary to acquire three-dimensional morphology, key dimensions, and surface contours in a timely manner to evaluate forging quality and provide a basis for subsequent processes. Structured light, binocular, or multi-view vision 3D measurement has advantages such as non-contact operation and rich information content. However, in the high-temperature forging environment, heat radiation and strong reflections reduce the contrast of fringe images; oxide scale, steam, and dust cause local occlusion; and forging vibration and positional changes can cause viewpoint mismatch, resulting in a measurement process exhibiting dynamic and random switching characteristics across multiple time scales. Simultaneously, the high-resolution images, fringe features, and point cloud data generated by multiple cameras and projectors are large in volume. If periodic sampling and full transmission are used, it can easily cause congestion of shared communication links and delays in 3D reconstruction. Open measurement communication networks are also susceptible to denial-of-service attacks and spoofing attacks, which can block or tamper with key viewpoint data, leading to missing contours, dimensional deviations, or reconstruction distortion. Existing 3D measurement solutions for high-temperature forging often focus on filtering suppression, fringe enhancement, point cloud repair, or calibration reconstruction, lacking a unified consideration of measurement stability under communication load, node scheduling, and network attack conditions. Therefore, it is necessary to provide a high-temperature forging three-dimensional measurement method that integrates dynamic event triggering, WTOD / RRP hybrid scheduling, attack modeling, modal recognition, asynchronous state observation, and sliding mode adjustment. Summary of the Invention

[0003] To overcome the aforementioned shortcomings of existing technologies, this invention provides a low-communication-load, attack-resistant security control method for a high-temperature forging 3D measurement system. This method addresses the challenges of 3D measurement environments characterized by high-temperature thermal radiation, strong reflections, oxide scale interference, forging vibration, concurrent multi-view data, and open communication links. It combines a dynamic event triggering mechanism, a hybrid scheduling protocol, network attack modeling, hidden Markov mode recognition, asynchronous state observation, and sliding mode adjustment. This reduces the communication load between images and point clouds while improving the stability, integrity, and robustness of high-temperature forging 3D morphology measurement under denial-of-service and spoofing attack conditions.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a low communication load anti-attack security control method for a high-temperature forging three-dimensional measurement system, comprising the following steps:

[0005] S1. Construct a three-dimensional measurement system model for high-temperature forging, and describe the process of multi-view image acquisition, fringe demodulation, three-dimensional reconstruction and projection and imaging parameter adjustment as a continuous-time Markov jump singular perturbation system, and establish the mathematical relationship between system state, measurement output and controlled output;

[0006] S2. Construct a dynamic event trigger evaluation function for the stripe image, contour feature or point cloud data collected by each three-dimensional measurement sensor node, and introduce dynamic auxiliary variables. Determine whether the current sampled data needs to be sent based on the comparison result between the evaluation function and the dynamic auxiliary variables, thereby reducing redundant data transmission under stable measurement conditions.

[0007] S3. When the event triggering condition is met, switch between the weighted first-come, first-served (WTOD) protocol and the round-robin (RRP) protocol based on the relationship between the evaluation function and the set threshold to achieve a hybrid scheduling transmission with priority given to critical viewpoint nodes and round-robin for regular viewpoint nodes; when the triggering condition is not met, keep the measurement data received in the previous moment unchanged.

[0008] S4. To address denial-of-service attacks and spoofing attacks in the communication link of the high-temperature forging three-dimensional measurement system, attack data transmission models are constructed to obtain the actual received output signals of the measurement control terminal.

[0009] S5. Based on the Hidden Markov Model, establish the conditional probability relationship between the actual measurement mode and the identification mode, construct an asynchronous state observer driven by the identification mode, and perform online estimation of the three-dimensional morphology measurement state of high-temperature forgings.

[0010] S6. Based on the state estimate and the identified mode, an asynchronous sliding mode control law is constructed, and the generated control input is applied to the projection and imaging parameter adjustment unit to achieve attack-resistant secure 3D measurement under low communication load conditions.

[0011] Furthermore, a three-dimensional measurement system model for high-temperature forging is constructed in S1 using the following method:

[0012] S11. The three-dimensional measurement process of high-temperature forging is modeled as a continuous-time Markov jump singular perturbation system, where the system modes are used to characterize different measurement conditions such as normal imaging, strong thermal radiation, local occlusion, forging vibration or viewpoint mismatch. The system state equation is expressed as formula (1):

[0013]

[0014] In the formula, This is a three-dimensional measurement of the high-temperature forging process. This is the control input applied to the projection and imaging parameter adjustment unit. Outputs include image, fringe feature, or point cloud measurements. This is a controlled output used to evaluate 3D topography reconstruction errors and measurement stability. A unified input for external disturbances and attacks such as thermal radiation, strong reflection, oxide scale obstruction, and forging vibration. This represents the actual three-dimensional measurement working condition mode. It is a constant matrix with the corresponding dimension under the known corresponding mode;

[0015] S12. Let the singular perturbation matrix be Equation (2):

[0016]

[0017] In the formula, For singular perturbation parameters, and It is a unit array;

[0018] S13. Multiple three-dimensional measurement sensor nodes are arranged in the high-temperature forging measurement area. The nodes include structured light projectors, industrial cameras and acquisition and processing modules. They periodically sample stripe images, contour features or point cloud data from different perspectives and send the sampled data to the measurement control terminal through a shared communication network.

[0019] Furthermore, in S2, a dynamic event-triggered evaluation function is constructed for the three-dimensional measurement data of high-temperature forging, and dynamic auxiliary variables are introduced using the following method:

[0020] S21, Let the first The measurement error of each three-dimensional measurement sensor node at the current sampling time is given by formula (3):

[0021]

[0022] In the formula, This is a continuous three-dimensional measurement signal from the current perspective. This refers to the most recently successfully transmitted sampling signal;

[0023] S22. Construct a dynamic event-triggered evaluation function. As shown in formula (4):

[0024]

[0025] In the formula, For weighted matrices, This is the trigger threshold parameter;

[0026] S23. Constructing dynamic auxiliary variables Its evolution equation can be expressed as formula (5):

[0027]

[0028] In the formula, and Given parameters, It is a diagonal matrix composed of the weight matrices of each three-dimensional measurement sensor node;

[0029] S24. Evaluation function With dynamic auxiliary variables The comparison is performed; when the evaluation function meets the preset triggering conditions, the current three-dimensional measurement sampling data is sent; when the evaluation function does not meet the preset triggering conditions, the data sent at the previous moment remains unchanged, thereby realizing the adaptive adjustment of the three-dimensional measurement data transmission frequency and reducing the communication load.

[0030] Furthermore, in S3, based on the relationship between the evaluation function of the 3D measurement data and the set threshold, the switching between the WTOD protocol and the RRP protocol is performed using the following method:

[0031] S31. Set the first trigger threshold according to the real-time performance, reconstruction accuracy, and safety requirements of three-dimensional measurement in high-temperature forging. Second trigger threshold ,and ;

[0032] S32. When the evaluation function satisfies formula (6), the weighted first-come, first-served (WTOD) protocol is activated to transmit high-priority 3D measurement node data corresponding to occluded boundaries, complex curvature regions, or critical dimension regions:

[0033]

[0034] S33. When the evaluation function does not meet the conditions of step S32, but meets the formula (7), the Round Robin Protocol (RRP) is activated to transmit the data of each conventional viewpoint node of the high-temperature forging three-dimensional measurement system in turn:

[0035]

[0036] S34. When the evaluation function does not satisfy the conditions of steps S32 and S33 at the same time, the current sampling data is not sent, and the data received by the measurement control terminal at the previous moment remains unchanged, so as to reduce redundant communication under stable measurement conditions.

[0037] Furthermore, an attack data transmission model for the communication link of the high-temperature forging three-dimensional measurement system is constructed in S4 using the following method:

[0038] S41. In the WTOD transmission mode of the high-temperature forging three-dimensional measurement system, introduce denial-of-service attack variables. The probability distribution of the data blocking situation satisfies formula (8):

[0039]

[0040] In the formula, This indicates that the current data transmission has been blocked. This indicates that the current transmission is normal;

[0041] S42. In WTOD transmission mode, the first... The actual received signal of a key three-dimensional measurement sensor node in high-temperature forging can be expressed as formula (9):

[0042]

[0043] S43. In the RRP transmission mode of the high-temperature forging three-dimensional measurement system, introduce a deception attack variable. The probability distribution of the injected false data satisfies formula (10):

[0044]

[0045] In the formula, This indicates that the currently transmitted data has been replaced by an attack signal. This indicates that the current transmission is normal;

[0046] S44. In RRP transmission mode, the first... The actual received signal of a conventional three-dimensional measurement sensor node can be expressed as formula (11):

[0047]

[0048] In the formula, For deception attack weighted matrix, Injecting signals to target attacks on high-temperature forging 3D measurement data;

[0049] S45. Based on the denial-of-service attack model and the spoofing attack model, construct the actual received output signal of the measurement control terminal to provide a data basis for subsequent observation of the three-dimensional morphology of high-temperature forgings and generation of parameter adjustment quantities.

[0050] Furthermore, in S5, a conditional probability relationship between the actual 3D measurement mode and the identified mode is established based on a hidden Markov model, and an asynchronous state observer is constructed using the following method:

[0051] S51. Establish actual three-dimensional measurement working condition modes With recognition modality The conditional probability matrix between them satisfies formula (12):

[0052]

[0053] In the formula, This indicates that the actual three-dimensional measurement mode is... The corresponding recognition mode is The probability of;

[0054] S52. The probability parameters of each three-dimensional measurement mode in the conditional probability matrix satisfy formula (13):

[0055]

[0056] S53. Based on the actual received output signal and identified mode of the measurement and control terminal, an asynchronous state observer is constructed, and its expression is formula (14):

[0057]

[0058] In the formula, This is an estimated value for the three-dimensional morphology measurement of high-temperature forgings. For observer output, The observer gain corresponding to the identified three-dimensional measurement mode;

[0059] S54. Since there may be a mismatch between the identified mode and the actual working mode of the high-temperature forging three-dimensional measurement system, the observer gain is scheduled according to the identified mode, thereby forming an asynchronous observation mechanism that adapts to the switching of measurement working conditions.

[0060] Furthermore, in S6, an asynchronous sliding mode control law is constructed based on the estimated three-dimensional morphology state of the high-temperature forging and the identified modes, using the following method:

[0061] S61. Construct an integral sliding surface using the state estimate to comprehensively compensate for high-temperature thermal radiation, strong reflection, oxide scale obstruction, forging vibration, parameter perturbation, and network attacks. Its expression is formula (15):

[0062] in, For a pre-designed constant matrix, For the gain of the sliding mode controller;

[0063] S62. Based on the identified high-temperature forging three-dimensional measurement modal design, an asynchronous sliding mode control law is designed, as shown in formula (16):

[0064]

[0065] In the formula, To provide the state feedback gain corresponding to the identified three-dimensional measurement mode, For sliding mode gain, It is a sliding surface;

[0066] S63. Apply the control input to the projection and imaging parameter adjustment unit to ensure that the high-temperature forging three-dimensional measurement system maintains safe and stable measurement under conditions of high-temperature interference, limited communication bandwidth, and network attacks.

[0067] Compared with existing technologies, the beneficial effects of this application in the three-dimensional measurement of high-temperature forging are as follows:

[0068] This invention combines a dynamic event triggering mechanism, a hybrid scheduling protocol, network attack modeling, hidden Markov mode recognition, asynchronous state observation, and sliding mode adjustment. It can adaptively switch between prioritizing transmission of critical perspectives, ensuring fair access to regular perspectives, and reducing transmissions under stable measurement conditions, based on the urgency of measurement data from various angles of high-temperature forgings. This reduces communication resource consumption for high-resolution images, fringe features, and point cloud data, and improves the stability and robustness of the high-temperature forging 3D measurement system under denial-of-service and spoofing attacks. In corresponding numerical verification, compared to the periodic triggering method, the total number of scalar transmission channels can be reduced from 10,000 to 222, a reduction of approximately 97.8%. Attached Figure Description

[0069] Figure 1 This is the overall control block diagram of the three-dimensional measurement system for high-temperature forging according to the present invention.

[0070] Figure 2 This is a flowchart illustrating the execution of the low-communication-load, attack-resistant, secure three-dimensional measurement method of the present invention.

[0071] Figure 3 A schematic diagram of dynamic event triggering and hybrid scheduling joint decision-making for three-dimensional measurement data of high-temperature forging.

[0072] Figure 4 This diagram illustrates the switching between three transmission states under a hybrid scheduling protocol for a high-temperature forging three-dimensional measurement system.

[0073] Figure 5 This is a schematic diagram showing the correspondence between the actual working conditions and the identified modes in the three-dimensional measurement of high-temperature forging.

[0074] Figure 6 This is a comparison diagram of the communication performance of the present invention when used for three-dimensional measurement of high-temperature forging with existing triggering methods. Detailed Implementation

[0075] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0076] This invention addresses the challenges in high-temperature forging 3D measurement systems, including thermal radiation, strong reflections, oxide scale and dust obstruction, forging vibration, multi-view data concurrency, limited communication resources, shared channel contention, denial-of-service attacks, spoofing attacks, and measurement condition mode recognition mismatch. It proposes a low-communication-load, attack-resistant security control method. This method combines a dynamic event triggering mechanism, a WTOD / RRP hybrid scheduling protocol, network attack modeling, hidden Markov mode recognition, asynchronous state observation, and sliding mode adjustment. This reduces image and point cloud communication overhead while improving the security, stability, and robustness of high-temperature forging 3D morphology measurement.

[0077] The method of the present invention includes the following steps:

[0078] 1. Construct a three-dimensional measurement system model for high-temperature forging.

[0079] First, the multi-view image acquisition, fringe demodulation, three-dimensional reconstruction, and projection and imaging parameter adjustment objects in the three-dimensional measurement process of high-temperature forging are modeled as a continuous-time Markov jump singular perturbation system, and its state equation is expressed as formula (1):

[0080]

[0081] In the formula, This is a three-dimensional measurement of the high-temperature forging process. This is the control input applied to the projection and imaging parameter adjustment unit. Outputs include image, fringe feature, or point cloud measurements. This is a controlled output used to evaluate 3D topography reconstruction errors and measurement stability. A unified input for external disturbances and attacks such as thermal radiation, strong reflection, oxide scale obstruction, and forging vibration. This represents the actual three-dimensional measurement working condition mode. It is a constant matrix with corresponding dimension in the known corresponding modes.

[0082] Furthermore, the singular perturbation matrix used to characterize the scale differences between the fast dynamics of image acquisition and fringe demodulation, and the slow dynamics of 3D reconstruction and parameter adjustment, is expressed as formula (2):

[0083]

[0084] In the formula, For singular perturbation parameters, and and This is the identity matrix of the corresponding dimension;

[0085] Furthermore, the actual working mode of the high-temperature forging three-dimensional measurement system. Described by a continuous-time Markov chain, its mode transition probability satisfies formula (3):

[0086]

[0087] In the formula, This indicates that the high-temperature forging three-dimensional measurement system consists of working condition modes. Switch to operating mode The transfer rate . For time intervals.

[0088] The above modeling method can simultaneously characterize the fast and slow dynamic coupling characteristics of image acquisition, fringe demodulation, 3D reconstruction and parameter adjustment in high-temperature forging 3D measurement, as well as the random mode switching characteristics caused by working conditions such as normal imaging, strong thermal radiation, local occlusion, forging vibration or viewpoint mismatch.

[0089] 2. Construct a dynamic event triggering mechanism for three-dimensional measurement in high-temperature forging.

[0090] To reduce the load on the shared communication link from multi-view high-resolution images, stripe features, and point cloud data, a dynamic event triggering mechanism is constructed for the output data collected by each 3D measurement sensor node.

[0091] Let the first The measurement error of each three-dimensional measurement sensor node at the current sampling time is given by formula (4):

[0092]

[0093] In the formula, This is a continuous three-dimensional measurement signal from the current perspective. This is the most recently successfully transmitted sampling signal.

[0094] A dynamic event-triggered evaluation function is constructed based on measurement error, as shown in formula (5):

[0095]

[0096] In the formula, It is a positive definite weighted matrix. This is the trigger threshold parameter.

[0097] Furthermore, construct dynamic auxiliary variables. Its evolution equation is expressed as formula (6):

[0098]

[0099] In the formula, and The parameters are given based on the real-time performance and accuracy requirements of three-dimensional measurement in high-temperature forging. .

[0100] At each sampling moment of the high-temperature forging three-dimensional measurement system, the measurement error and event trigger evaluation function are first calculated according to formulas (4) and (5), then the dynamic auxiliary variable is updated according to formula (6), and finally, the current sampling data is sent based on the comparison result between the evaluation function and the dynamic auxiliary variable. This is achieved by introducing dynamic auxiliary variables. This allows the trigger threshold to adaptively adjust according to changes in image quality, viewpoint occlusion, and 3D topography, thereby reducing unnecessary data transmission.

[0101] 3. Perform WTOD / RRP hybrid scheduling decisions based on the urgency of 3D measurement data.

[0102] After completing the evaluation function and dynamic auxiliary variable calculation for the three-dimensional measurement data from each perspective, a two-level trigger decision is executed to achieve hybrid scheduling of WTOD and RRP.

[0103] Set the first trigger threshold Second trigger threshold And satisfy .

[0104] When the evaluation function satisfies formula (7), proceed to Case A and enable the Weighted First-Come, First-Served (WTOD) protocol to give priority to the measurement nodes corresponding to occluded boundaries, complex curvature regions, or critical size regions:

[0105]

[0106] When the evaluation function does not satisfy formula (7) but satisfies formula (8), proceed to Case B and enable the Round Robin Protocol (RRP) so that each conventional viewpoint 3D measurement node can obtain a transmission opportunity in turn:

[0107]

[0108] When the evaluation function does not satisfy both formula (7) and formula (8), it enters Case C, does not send the current sampled data, and keeps the data received by the measurement control terminal at the previous moment unchanged, so as to suppress redundant data under stable measurement conditions.

[0109] like Figure 3 As shown, at each sampling moment of the high-temperature forging three-dimensional measurement system, the measurement error and dynamic event triggering evaluation function are first calculated, then the dynamic auxiliary variables are updated, and then the results are compared sequentially. and , The size relationship allows switching between three scenarios: WTOD transmission with priority given to critical viewpoint nodes, RRP transmission with rotation of regular viewpoint nodes, and no updates during stable measurement conditions.

[0110] like Figure 4 As shown in the figure, the switching sequence of the three states, Case A, Case B, and Case C, in the hybrid scheduling protocol of the high-temperature forging 3D measurement system is illustrated. This hybrid scheduling method can dynamically switch transmission strategies based on the degree of viewpoint occlusion, surface curvature, critical size areas, and image quality. In complex or abrupt regions, it prioritizes the protection of critical measurement data, while in stable regions, it ensures fair access to conventional viewpoints and reduces communication load.

[0111] 4. Construct a data transmission model of a high-temperature forging three-dimensional measurement system under attack.

[0112] In the WTOD transmission mode of the high-temperature forging three-dimensional measurement system, a denial-of-service attack variable is introduced. The probability distribution of data blocking conditions satisfies formula (9):

[0113]

[0114] In the formula, This indicates that the three-dimensional measurement data from the key perspective of high-temperature forging is currently blocked. This indicates that the current transmission is normal.

[0115] Under these conditions, the first The actual received signal of a key three-dimensional measurement sensor node in high-temperature forging can be expressed as formula (10):

[0116]

[0117] Furthermore, in the RRP transmission mode of the high-temperature forging three-dimensional measurement system, a deception attack variable is introduced. The probability distribution of the injected false data satisfies formula (11):

[0118]

[0119] In the formula, This indicates that the current three-dimensional measurement data for high-temperature forging has been replaced by an attack signal. This indicates that the current transmission is normal.

[0120] Under these conditions, the first The actual received signal of a conventional three-dimensional measurement sensor node can be expressed as formula (12):

[0121]

[0122] In the formula, For deception attack weighted matrix, Injecting signals to target attacks on three-dimensional measurement data of high-temperature forging.

[0123] Therefore, in the high-temperature forging three-dimensional measurement application of this invention, the measurement control terminal ultimately uses not the ideal output, but the actual received output signal affected by both denial-of-service attacks and spoofing attacks. .

[0124] 5. Modal Identification and Asynchronous State Observation of High-Temperature Forging Three-Dimensional Measurement Conditions Based on Hidden Markov Models (HMMs)

[0125] Because the three-dimensional measurement process of high-temperature forging involves switching between conditions such as normal imaging, strong heat radiation, local occlusion, forging vibration, and viewing angle mismatch, and because thermal disturbances and network transmission can cause delays or loss of measurement modal information, it is difficult for the measurement controller and observer to always synchronously obtain the true measurement modal. Therefore, this invention uses a hidden Markov model to establish the conditional probability relationship between the actual measurement modal and the identified modal.

[0126] Let the actual three-dimensional measurement working condition mode be: The identified modality is Then the conditional probability relationship between the two can be expressed as formula (13):

[0127]

[0128] In the formula, This indicates that the actual three-dimensional measurement mode is... The corresponding recognition mode is The probability of.

[0129] Furthermore, the conditional probability parameters of each high-temperature forging three-dimensional measurement mode satisfy formula (14):

[0130]

[0131] Based on the actual received output signal and identified mode of the measurement and control terminal, an asynchronous state observer is constructed, and its expression is formula (15):

[0132]

[0133] In the formula, This is an estimated value for the three-dimensional morphology measurement of high-temperature forgings. For observer output, The observer gain is the value corresponding to the identified three-dimensional measurement mode.

[0134] Since there may be a mismatch between the identified mode and the actual working mode of the high-temperature forging three-dimensional measurement system, the observer gain is scheduled according to the identified mode, while the measurement process still operates according to the actual working mode, thus forming an asynchronous observation mechanism that adapts to the switching of measurement working conditions.

[0135] like Figure 5 As shown in the figure, the actual working mode of three-dimensional measurement during high-temperature forging is presented. With recognition modality The correspondence. (By...) Figure 5 It is evident that modal identification can, to a certain extent, track the modal change trend under actual working conditions of high-temperature forging three-dimensional measurement. Although there are local mismatches, it can still provide effective modal information for asynchronous observation and parameter adjustment of the three-dimensional morphology of high-temperature forgings.

[0136] 6. Construct an integral sliding mode surface adapted to high-temperature optical interference and generate parameter adjustment values.

[0137] To improve the robustness of the high-temperature forging three-dimensional measurement system to network attacks, thermal radiation, strong reflection, oxide scale obstruction, forging vibration, parameter uncertainty, and modal mismatch, a sliding mode adjustment mechanism is further adopted in this embodiment.

[0138] First, an integral sliding surface is constructed based on the estimated three-dimensional morphology of the high-temperature forging to compensate for high-temperature optical interference and forging vibration. Its expression is formula (16):

[0139]

[0140] In the formula, The parameter matrix of the sliding surface is pre-designed to address high-temperature thermal radiation, strong reflection, local shading, and forging vibration. It is the gain of the sliding mode controller.

[0141] Based on this, an asynchronous sliding mode control law is generated based on the identified three-dimensional measurement working condition modes, expressed as formula (17):

[0142]

[0143] In the formula, To provide the state feedback gain corresponding to the identified three-dimensional measurement mode, For sliding mode gain, For sliding surface, It is a symbolic function.

[0144] By applying the above control inputs to the projection and imaging parameter adjustment units such as structured light projection intensity, camera exposure time, gain, or acquisition timing, the system can maintain the stability and integrity of the three-dimensional morphology measurement of high-temperature forgings even under conditions of discontinuous measurement data updates, network attacks, high-temperature optical interference, and modal mismatch.

[0145] 7. Algorithm Implementation for a Three-Dimensional Measurement System for High-Temperature Forging

[0146] Numerical verification was performed on a high-temperature forging three-dimensional measurement system to illustrate the implementation steps of the proposed method under conditions of measurement mode switching, network attacks, and bandwidth constraints. Figure 4 , Figure 5 and Figure 6 As shown.

[0147] S1. Construct a continuous-time Markov jump singular perturbation system model. Based on formulas (1) and (2), establish the state equation, measurement output equation, and controlled output equation of the three-dimensional measurement process of high-temperature forging. Based on formula (3), set the mode transfer relationship of measurement conditions such as normal imaging, strong thermal radiation, local occlusion, forging vibration, or viewpoint mismatch, thereby describing the random condition switching and fast-slow dynamic coupling behavior.

[0148] S2, calculate the dynamic event trigger evaluation function of the three-dimensional measurement data and update the dynamic auxiliary variables. Calculate the measurement error at the current sampling time according to formula (4), calculate the event trigger evaluation function according to formula (5), and update the dynamic auxiliary variables according to formula (6) so that the trigger threshold is adaptively adjusted according to image quality, viewpoint occlusion and three-dimensional shape status.

[0149] S3, perform hybrid scheduling switching based on the urgency and threshold relationship of the three-dimensional measurement data. When the evaluation function satisfies formula (7), enter Case A, enable the WTOD protocol, and prioritize the transmission of key view measurement data; when the evaluation function does not satisfy formula (7) but satisfies formula (8), enter Case B, enable the RRP protocol, and allow regular view nodes to transmit in turn; when neither of the two is satisfied, enter Case C, and keep the received data from the previous moment unchanged. Figure 4 The image shows the switching results for the three transmission scenarios.

[0150] S4. In the process of three-dimensional measurement and communication during high-temperature forging, an attack data transmission model is constructed. In the WTOD mode, the critical view reception signal model under denial-of-service attack is constructed according to formula (9) and formula (10); in the RRP mode, the conventional view reception signal model under deception attack is constructed according to formula (11) and formula (12), thereby obtaining the actual received output signal of the measurement control terminal.

[0151] S5. Based on HMM, three-dimensional measurement working condition mode identification is performed and an asynchronous state observer is constructed. According to formula (13) and formula (14), the conditional probability relationship between the actual measurement working condition mode and the identified mode is established, and according to formula (15), the asynchronous state observer is constructed to estimate the three-dimensional morphology measurement state of the high-temperature forging online. Figure 5 The diagram shows the correspondence between the actual measured operating mode and the identified mode.

[0152] S6. Construct an integral sliding surface adapted to high-temperature optical interference and generate parameter adjustment quantities. Construct an integral sliding surface according to formula (16), generate asynchronous sliding control input according to formula (17), and apply it to parameter adjustment units such as projection intensity, camera exposure time, gain, or acquisition timing to complete the low communication load anti-attack security control of the high-temperature forging three-dimensional measurement system.

[0153] 8. Explanation of the Implementation Effect of Three-Dimensional Measurement in High-Temperature Forging

[0154] To verify the effectiveness of the present invention in a high-temperature forging three-dimensional measurement system, the method was compared and verified, and compared with periodic triggering method and static event triggering method. Figure 6 The results of communication performance comparison under different triggering methods are presented, including total number of triggers, total number of transmission scalar channels, average event interval, and measurement closed-loop performance indicators, which are used to evaluate the communication load and measurement stability in multi-view image, stripe feature, and point cloud data transmission.

[0155] Depend on Figure 6 As can be seen, this invention significantly reduces the communication load while maintaining the essentially unchanged closed-loop performance of high-temperature forging three-dimensional measurement. Specifically, compared to the periodic triggering method, the total number of scalar transmission channels is reduced from 10,000 to 222, a reduction of approximately 97.8%. Compared to the static event triggering method, although the number of triggers increases slightly, the total number of transmission channels is still less because WTOD / RRP only sends the necessary viewpoints and necessary channel data, while the measurement closed-loop performance indicators remain essentially unchanged.

[0156] Verification results show that the present invention can effectively reduce the communication resource consumption of the high-temperature forging three-dimensional measurement system without significantly sacrificing measurement performance. It is suitable for online three-dimensional measurement scenarios of high-temperature forgings with thermal radiation, strong reflection, oxide scale obstruction, forging vibration, measurement mode jump, network attacks and bandwidth limitations.

[0157] 9. Implementation method of high-temperature forging three-dimensional measurement system

[0158] A high-temperature forging three-dimensional measurement system includes a data acquisition unit, an event triggering and scheduling unit, an attack processing unit, a state observation unit, a control input generation unit, and a parameter adjustment unit, used to execute the low communication load anti-attack security control method of the high-temperature forging three-dimensional measurement system;

[0159] The data acquisition unit includes a structured light projector, multiple industrial cameras, and an acquisition and processing module, used to acquire stripe images, contour features, or point cloud data of high-temperature forgings from different perspectives.

[0160] The event triggering and scheduling unit is used to construct a dynamic event triggering evaluation function based on the measurement error of the three-dimensional measurement data, and switch between three states according to the evaluation function and the threshold relationship: the WTOD protocol with priority to key viewpoint nodes, the RRP protocol with rotation of regular viewpoint nodes, and the stable measurement condition without updating.

[0161] The attack processing unit is used to characterize the three-dimensional measurement data transmission behavior under denial-of-service attacks and spoofing attacks, and to generate the actual received output signal of the measurement control terminal.

[0162] The state observation unit is used to establish the relationship between the actual measurement working condition mode and the identified mode based on the hidden Markov model, and to construct an asynchronous state observer to estimate the three-dimensional morphology measurement state of the high-temperature forging online.

[0163] The control input generation unit is used to construct an integral sliding surface that can compensate for the effects of high-temperature optical interference, forging vibration and network attacks, and generate asynchronous sliding control input;

[0164] The parameter adjustment unit is used to adjust the structured light projection intensity, camera exposure time, gain, or acquisition timing according to the control input, so as to achieve low communication load, anti-attack, and secure 3D measurement.

[0165] In summary, this invention achieves low-communication-load, attack-resistant security control for a high-temperature forging 3D measurement system by constructing a continuous-time Markov jump singular perturbation system model for the high-temperature forging 3D measurement process, a dynamic event triggering mechanism, a WTOD / RRP hybrid scheduling protocol, a denial-of-service attack and spoofing attack data transmission model, an asynchronous state observer for measurement condition modal identification based on a hidden Markov model, and an integral sliding mode control law. This method prioritizes measurement data from occluded boundaries, complex curvature regions, and critical dimension regions, reduces redundant image and point cloud transmission in stable regions, and maintains the stability, integrity, and robustness of 3D measurements under conditions of high-temperature optical interference, network attacks, and modal mismatch.

Claims

1. A low-communication-load anti-attack security control method for a high-temperature forging three-dimensional measurement system, characterized in that, Includes the following steps: S1. Construct a three-dimensional measurement system model for high-temperature forging. The system includes a multi-view three-dimensional measurement sensor node for high-temperature forgings, a shared communication network, a measurement controller, and a projection and imaging parameter adjustment unit. S2. Construct a dynamic event-triggered evaluation function for the image, stripe feature or point cloud measurement data collected by each three-dimensional measurement sensor node, and combine dynamic auxiliary variables to determine whether the current sampled data needs to be sent, so as to reduce redundant measurement data transmission in the high-temperature forging site. S3. When the event triggering condition is met, switch between the Weighted First-Come, First-Served (WTOD) protocol and the Round-Robin (RRP) protocol according to the triggering strength to achieve a hybrid scheduling transmission with priority given to critical viewpoint nodes and round-robin scheduling for regular viewpoint nodes; when the triggering condition is not met, keep the measurement data received in the previous moment unchanged. S4. To address denial-of-service attacks and spoofing attacks in the communication link of the high-temperature forging three-dimensional measurement system, attack data transmission models are constructed to obtain the actual received signals from the measurement control terminal. S5. Based on the Hidden Markov Model, the measurement mode of the three-dimensional measurement system for high-temperature forging is identified, and an asynchronous state observer is constructed according to the identified mode to estimate the measurement state of the three-dimensional morphology of the high-temperature forging online. S6. Construct an asynchronous sliding mode control law based on the state estimate and the identified mode, and apply the control input to the projection and imaging parameter adjustment unit to achieve anti-attack secure 3D measurement while reducing the communication load.

2. The low communication load anti-attack security control method for a high-temperature forging three-dimensional measurement system according to claim 1, characterized in that, The specific steps for S1 are as follows: S11. The high-temperature forging three-dimensional measurement process is modeled as a continuous-time Markov jump singular perturbation system to describe the fast dynamics of image acquisition and fringe demodulation, the slow dynamics of three-dimensional reconstruction and parameter adjustment, and the random switching between different measurement conditions. The system state equation is expressed as: (1) in, This is a three-dimensional measurement of the high-temperature forging process. This is the control input applied to the projection and imaging parameter adjustment unit. Outputs include image, fringe feature, or point cloud measurements. This is a controlled output used to evaluate 3D topography reconstruction errors and measurement stability. A unified input for external disturbances and attacks such as thermal radiation, strong reflection, oxide scale obstruction, and forging vibration. This is the actual three-dimensional measurement mode. It is a constant matrix with the corresponding dimension under the known corresponding mode; S12. Let the singular perturbation matrix used to characterize the difference in dynamic scale between fast and slow during the three-dimensional measurement process of high-temperature forging be: (2) in, For singular perturbation parameters, and It is a unit array; S13. Multiple three-dimensional measurement sensor nodes are arranged in the high-temperature forging measurement area. The nodes include structured light projectors, industrial cameras and their acquisition and processing modules, which periodically sample stripe images, contour features or point cloud data from different perspectives, and send the sampled data to the measurement control terminal through a shared communication network.

3. The low communication load anti-attack security control method for a high-temperature forging three-dimensional measurement system according to claim 1, characterized in that, The specific steps for S2 are as follows: S21, Let the first The measurement error of a three-dimensional measurement sensor node at the current three-dimensional measurement sampling time can be expressed as formula (3): (3) in, This is a continuous three-dimensional measurement signal from the current perspective. This refers to the most recently successfully transmitted sampling signal; S22. Construct a dynamic event-triggered evaluation function to measure the necessity of updating three-dimensional measurement data in high-temperature forging: (4) in, For weighted matrices, This is the trigger threshold parameter; S23. Constructing dynamic auxiliary variables And the evaluation function With dynamic auxiliary variables The comparison is performed; when the evaluation function meets the preset triggering conditions, the current three-dimensional measurement sampling data is sent; when the evaluation function does not meet the preset triggering conditions, the data sent at the previous moment remains unchanged, thereby realizing the adaptive adjustment of the three-dimensional measurement data transmission frequency and reducing the communication load. (5) in, as well as It is a defined scalar quantity. The weighted matrix is ​​known.

4. The low communication load anti-attack security control method for a high-temperature forging three-dimensional measurement system according to claim 1, characterized in that, The specific steps for S3 are as follows: S31. Set a first trigger threshold that meets the real-time performance, reconstruction accuracy, and safety requirements of three-dimensional measurement in high-temperature forging. Second trigger threshold ,and : S32, when the evaluation function satisfies (6) When the weighted first-come, first-served protocol (WTOD) is activated, high-priority 3D measurement sensor node data corresponding to shading boundaries, areas with strong heat radiation, complex curvature areas, or critical size areas are transmitted. When the evaluation function does not satisfy the condition in step S32, but satisfies (7) At that time, the Round Robin Protocol (RRP) is enabled to transmit data from each conventional perspective sensor node of the high-temperature forging three-dimensional measurement system in turn; When the evaluation function does not meet the conditions of steps S32 and S33 at the same time, the current sampling data is not sent, and the data received by the measurement control terminal at the previous moment remains unchanged, so as to reduce the occupation of the shared communication link by the 3D image and point cloud data.

5. A low-communication-load anti-attack security control method for a high-temperature forging three-dimensional measurement system according to claim 1, characterized in that, The specific steps for S4 are as follows: S41. In the WTOD transmission mode, a denial-of-service attack variable is introduced to characterize the blocking of 3D measurement data from key perspectives. When a denial-of-service attack occurs, the current sampled data cannot reach the measurement control terminal, and the measurement control terminal retains the data received at the previous moment. S42. In RRP transmission mode, a deception attack variable is introduced to characterize the injection of false data in conventional 3D measurement data; when a deception attack occurs, the attack signal replaces the original image, stripe feature or point cloud measurement data and enters the measurement control terminal. S43. Based on the denial-of-service attack model and the spoofing attack model, construct the actual received output signal of the measurement control terminal to provide a data foundation for subsequent three-dimensional measurement state observation and parameter adjustment quantity generation.

6. A low-communication-load anti-attack security control method for a high-temperature forging three-dimensional measurement system according to claim 1, characterized in that, The specific steps for S5 are as follows: S51. Establish actual three-dimensional measurement working condition modes With recognition modality The conditional probability matrix between: in, This indicates that the actual three-dimensional measurement mode is... The corresponding recognition mode is The probability is calculated; based on the actual received output signal and identification mode of the measurement control terminal, an asynchronous state observer is constructed to estimate the three-dimensional morphology measurement state of the high-temperature forging online; since there may be a mismatch between the identification mode and the actual three-dimensional measurement working condition mode, the observer gain is scheduled according to the identification mode, thus forming an asynchronous observation mechanism.

7. A low-communication-load anti-attack security control method for a high-temperature forging three-dimensional measurement system according to claim 1, characterized in that, The specific steps for S6 are as follows: S61. Construct an integral sliding surface using state estimates to compensate for the effects of high-temperature thermal radiation, strong reflection, oxide scale, forging vibration, incomplete network transmission, modal mismatch, and attack disturbances on the three-dimensional measurement process. S62. Design of asynchronous sliding mode control law based on the identified high-temperature forging three-dimensional measurement modal: in, To provide the state feedback gain corresponding to the identified three-dimensional measurement mode, For sliding mode gain, For sliding surface functions; S63. Apply the control input to the projection and imaging parameter adjustment unit so that the high-temperature forging three-dimensional measurement system can resist denial-of-service attacks and spoofing attacks while reducing the communication load.

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