A Servo Control Guarantee Method for Ancient Shipwreck Archaeology

Abstract

This invention discloses a servo control support method for ancient shipwreck archaeology. First, a parameterized numerical model covering all possible deployment locations is established. Second, through a series of numerical experiments, the axial force of each candidate support is changed one by one, and the resulting changes in the internal forces of all other supports within the entire support network are accurately calculated, thus constructing a complete stress-influence relationship matrix. This matrix is ​​the core knowledge base describing the internal mechanical relationships of the system. Then, using this matrix as key input, a mathematical programming model is constructed with the goal of minimizing the deformation of the protected object and achieving the most balanced support stress. Finally, an optimization algorithm is used to solve the model, and the solution is the optimal support layout scheme and the optimal axial force benchmark value for each selected support. This invention realizes a shift from single-point control to a system-wide collaborative support design concept, significantly improving the overall efficiency and safety of the servo support system in complex environments.

Description

Technical Field

[0001] This invention relates to the fields of geotechnical engineering and numerical optimization technology, and in particular to a servo control guarantee method for ancient shipwreck archaeology. Background Technology

[0002] In meticulous excavation projects such as ancient shipwreck archaeology, multiple steel support systems are often used to control the deformation of the shipwreck and the protected structure. The stress and deformation of each support change continuously during the excavation process. Traditional methods of fixing the axial force of steel supports or limiting the steel supports are not suitable for ancient shipwrecks that are sensitive to support forces and have high protection requirements. However, servo steel supports, due to their ability to dynamically adjust the axial force, offer the possibility of adapting to complex working conditions. However, the support system is a whole; a change in the stress state of any support will cause a redistribution of internal forces in other supports through the supported structure and the surrounding soil. Traditional design methods often consider the stress of individual supports in isolation or make empirical arrangements, ignoring this systemic interaction.

[0003] The main bottlenecks in this field are: (1) lack of effective means to quantitatively describe the complex mechanical transmission relationship of a change in one point in the support system and the response of the whole network; (2) existing optimization methods are mostly aimed at the cross-sectional size, material grade or simple spacing of the support, and rarely take the stress influence relationship between supports as a clear optimization parameter and constraint; (3) in the application of servo support, more attention is paid to its single-point tracking compensation capability, but its deployment position and initial force system are not planned in advance at the system level to maximize its collaborative work benefits. Summary of the Invention

[0004] To address the aforementioned issues, the present invention aims to provide a servo control support method for ancient shipwreck archaeology, fundamentally improving the collaborative load-bearing efficiency of the entire support system and minimizing stress deficiencies. By optimizing the layout and presetting the reference axial force, the system achieves better stress balance in the initial state, reducing the magnitude and frequency of subsequent dynamic adjustments. This lays a theoretical foundation for understanding the working mechanism of complex support systems and enabling intelligent control.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a servo control support method for ancient shipwreck archaeology, characterized by the following steps: Step 1: Establishing a parameterized support system numerical model: Constructing a three-dimensional finite element model including the ancient ship, surrounding soil, jacking pipe, fishbone structure, and all supports, wherein the supports are defined as beam elements and their constitutive models are fixed; Step 2: Single support adjustment stress impact analysis: Selecting a candidate support in the system, and calculating and analyzing the change in the axial force of all other supports in the system caused by this change in the numerical model by locking relative displacement and external axial force, thereby obtaining the stress impact of this support on the entire system; Step 3: Constructing a system stress impact relationship matrix: For each candidate support in the system, repeating step 2, combining all stress impact vectors to form a stress impact relationship matrix describing the impact of any support adjustment on the rest of the system; Step 4: Support system collaborative optimization: With the goal of minimizing the deformation of key shipwreck indicators, balancing the actual axial force of each support, and satisfying the support bearing capacity constraints, establishing a mathematical optimization model, using the stress impact relationship matrix obtained in step 3 as the core parameter input, and solving through an optimization algorithm to determine the optimal placement subset of servo steel supports and the optimal axial force reference value of each support position.

[0007] Furthermore, the servo control support method for ancient shipwreck archaeology provided by the present invention may also have the following feature: in step 2, the stress influence vector includes not only the change in axial force of all other supports in the system except for the candidate support, but also the displacement change and stress change of key points of the shipwreck.

[0008] Furthermore, the servo control guarantee method for ancient shipwreck archaeology provided by the present invention may also have the following feature: in step 4, the objective function of the mathematical optimization model is a multi-objective function, including minimizing the maximum displacement of the shipwreck, minimizing the maximum stress, and minimizing the sum of squares of the differences between the axial forces of each support and the average axial force.

[0009] The present invention reveals and utilizes the inherent stress transmission and redistribution laws within the support system, and uses these laws as guidance to optimize the selection of specific locations where servo steel supports need to be placed. Simultaneously, it determines a set of axial force reference values ​​for each support that optimizes the collaborative performance of the entire system under target operating conditions. Essentially, this solution finds a support configuration that maximizes stress transmission and synergistic effects within the system.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] (1) System thinking orientation: This invention explicitly uses the stress influence relationship between supports as the core basis for optimization design, realizing true system optimization rather than local component optimization.

[0012] (2) Prediction and proactive design: The method of the present invention can predict the synergistic effect of different layout schemes before construction and proactively design the optimal initial force system so that the servo system can start working from a better starting point.

[0013] (3) Combination of mechanism and data-driven approach: The mechanical mechanism revealed by finite element numerical simulation is transformed into a quantifiable influence matrix, which in turn drives the mathematical optimization model, thus combining theoretical rigor with solution feasibility.

[0014] (4) The output results are directly usable: The optimization results of the method of the present invention directly provide two key decisions: where to deploy and how much force to initially set, which has clear guiding significance for engineering. Attached Figure Description

[0015] Figure 1 This is an overall flowchart of the servo control guarantee method for ancient shipwreck archaeology in an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the displacement and axial force control of the candidate support in an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of the stress cloud diagram of the support system in an embodiment of the present invention. Detailed Implementation

[0018] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0019] Please see Figure 1 This embodiment takes the Yangtze River Estuary No. 2 ancient shipwreck as an example to provide a servo control guarantee method for ancient shipwreck archaeology. The method is carried out according to the following steps:

[0020] Step 1: Numerical Modeling and Calculation

[0021] For the archaeological excavation pit of the No. 2 ancient shipwreck in the Yangtze River estuary, a 3D model including the hull, soil, and external curved beams was created in Abaqus software. A batch of beam elements were created at preset support locations around the hull to simulate candidate servo supports. Their relative displacement and applied axial force were used as design variable parameters. The model was run, and all supports were retained in the display group, resulting in the following... Figure 3 The stress contour plot shown represents the stress values ​​in various directions (s) and the von Mises stress. The stress corresponding to each element in contact with the fishbone is recorded and organized into a vector {P}. 0i}

[0022] Step 2: Analysis of the Impact of Single Support Adjustment

[0023] To select the first candidate support, please refer to [link / reference]. Figure 2 The boundary conditions are set to a specified value for the connection displacement. ① indicates an external load applied based on the connection displacement, and ② indicates that the connection section is configured with a converter, allowing only radial (U1) deformation. The connector's stiffness (D11) in the x-direction is given based on the elastic model. For example... Figure 2 As shown, the relative displacement is controlled and a concentrated force ΔP is added at the point of contact between the support and the fishbone. Static calculations are run, and the element stress at each support contacting the fishbone is recorded, along with the initial recorded change in axial force ΔP for all other supports. i1 (i≠0 or 1), and the displacement changes of key measuring points on the ancient ship. This set {ΔP i1 The stress influence vector of the support is formed by the displacement change.

[0024] Step 3: Construct the system stress influence matrix

[0025] Repeat step two, applying the same perturbation ΔP to the 2nd, 3rd, ..., Nth candidate supports in sequence, and obtain their respective influence vectors. Arrange all vectors as shown in the following formula to obtain the stress influence matrix.

[0026] {P i}={P 0i}+ P1×{ΔP i1} + P2×{ΔP i2}+ P3×{ΔP i3}+……+P N ×{ΔP N1}

[0027] Step 4: Constructing the solution and optimization model

[0028] A mathematical optimization model was established with the objectives of minimizing the deformation of key shipwreck indicators, equalizing the actual axial force of each support, and satisfying the support bearing capacity constraints. The objective function of the mathematical optimization model is a multi-objective function, including minimizing the maximum displacement of the shipwreck, minimizing the maximum stress, and minimizing the sum of squares of the differences between the axial force of each support and the average axial force. The stress influence relationship matrix from the third step was used as the core parameter input, and the optimal subset of servo steel support locations and the optimal axial force reference value for each support location were determined through optimization algorithm.

[0029] In this embodiment, since the layout of servo steel is limited in actual engineering, the variables are selected as a set of 0 / 1 variables to indicate whether a servo support is laid at a certain candidate position, and a set of continuous variables to indicate the reference axial force value if it is laid. The following two objectives need to be met: (1) the maximum displacement of the key point of the ancient ship should be as small as possible; (2) the system should be as balanced as possible under the constraints that the axial force of each support is less than the allowable bearing capacity and the total number of supports laid is less than or equal to the upper limit, i.e., Minimize (∑(axial force of each support - average axial force)²).

[0030] Step 5: Output and Application of Results

[0031] A set of optimal solutions was obtained. Engineers can choose a compromise solution based on their preferences. The solution clarifies: (1) the key locations where servo steel supports should be installed; and (2) the initial reference axial force values ​​for these supports. Compared to the scheme that uses only ordinary steel supports, the optimized scheme has a significantly more uniform distribution of axial force, a lower peak force, and a significantly improved system synergy. This result can be directly used to guide the installation and initial setup of the servo support system on site.

[0032] Although the present invention has been described in detail with reference to the foregoing embodiments, it is obvious that the described embodiments are merely preferred embodiments of the present invention, and not all embodiments. For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A servo control guarantee method for ancient shipwreck archaeology, characterized in that, Includes the following steps: Step 1: Establish a parameterized support system numerical model: Construct a three-dimensional finite element model including the ancient ship, surrounding soil, pipe jacking, fishbone structure, and all supports; Step 2, Stress Influence Analysis of Single Support Adjustment: Select a candidate support in the system, and calculate and analyze the change in the axial force of all other supports in the system caused by this change in the numerical model by locking the relative displacement and the applied axial force, thereby obtaining the stress influence of this support on the entire system; Step 3: Construct the system stress influence matrix: For each candidate support in the system, repeat step 2 to combine all stress influence vectors to form a stress influence matrix that describes the effect of any support adjustment on the rest of the system. Step 4, Coordinated Optimization of Support System: With the goal of minimizing the deformation of key indicators of the sunken ship, equalizing the actual axial force of each support, and satisfying the bearing capacity constraints of the supports, a mathematical optimization model is established. The stress influence relationship matrix obtained in Step 3 is used as the core parameter input, and the optimal placement subset of servo steel supports and the optimal axial force reference value of each support are determined through optimization algorithm.

2. The servo control guarantee method for ancient shipwreck archaeology according to claim 1, characterized in that: In step 2, the stress influence vector includes not only the changes in the axial forces of all other supports in the system except for the candidate support, but also the changes in displacement and stress at key points of the sunken ship.

3. The servo control support method for ancient shipwreck archaeology according to claim 1, characterized in that: In step 4, the objective function of the mathematical optimization model is a multi-objective function, including minimizing the maximum displacement of the sunken ship, minimizing the maximum stress, and minimizing the sum of squares of the differences between the axial force of each support and the average axial force.

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