Full-automatic soil shrinkage tester and control method thereof

Abstract

The invention provides a full-automatic soil shrinkage tester and a control method thereof, and belongs to the technical field of control. Determining the test control sequence of the screening rotation speed intervals by combining the correlation degree between the test process of which the volume change curve meets the requirement and the volume change curve of other test rotation speed intervals, and performing test control processing of different screening rotation speed intervals according to the test control sequence; based on the consistency degree of the volume change curve in the screening rotation speed interval and the screening rotation speed interval data after the existing test is completed, the test control method of the full-automatic soil shrinkage tester in the screening rotation speed interval which is not tested is determined, and the reliability degree of deformation monitoring processing is improved.

Description

Technical Field

[0001] This invention belongs to the field of control technology, and in particular relates to a fully automatic soil shrinkage tester and its control method. Background Technology

[0002] Traditional soil shrinkage tests rely on manual operation. The main procedures include: manually placing the soil sample, periodically removing the sample for weighing, manually reading the dial gauge displacement data, and manually recording the data. This method has significant drawbacks: low efficiency (long test cycle, frequent manual intervention required), large errors (subjective errors easily introduced by manual reading and recording, and sample movement during weighing may disturb the soil), and inability to conduct continuous monitoring (difficult to achieve unattended long-term continuous data acquisition, and unable to fully capture the entire shrinkage process).

[0003] To address the aforementioned technical problems, for example, the invention patent application CN202510669688.0, "An Automated Test System and Method for Measuring Soil Shrinkage Process," compares three-dimensional models of remolded soil samples at different times to obtain changes in volume and vertical height of the remolded soil samples at different times, thereby obtaining a soil shrinkage curve. The beneficial effects of this invention are: it avoids human disturbance and reduces the complexity of experimental operations, and it can obtain continuously changing data throughout the process, making the data more representative. However, it still has the following drawbacks: Variations in platform speed may lead to deviations in the reliability of volumetric deformation monitoring obtained by laser scanning. Therefore, determining the experimental processing methods for different speed ranges based on the variation deviations of deformation curves in the same soil sample within different speed ranges, in order to quickly obtain the required speed ranges and improve the reliability of deformation monitoring processing, has become an urgent technical problem to be solved.

[0004] To solve the above-mentioned technical problems, this application provides a fully automatic soil shrinkage tester and its control method. Summary of the Invention

[0005] To achieve the objectives of this invention, the following technical solution is adopted: Specifically, this application provides a control method for a fully automatic soil shrinkage tester, which includes: S1 uses a soil shrinkage tester to determine the volume change curve of soil as moisture content changes, uses the volume change curve to determine the abnormal change period in the historical measurement process, and determines the adjustment strategy of the test rotation speed based on the abnormal change period data and the degree of overlap of the abnormal change period. S2 uses the adjustment strategy to adjust the test rotation speed. Based on the correlation between the volume change curve and other test rotation speed ranges, it determines the screening rotation speed range in the test rotation speed range. Using the test process data where the volume change curve in the screening rotation speed range meets the requirements, and combining the correlation between the test process where the volume change curve meets the requirements and the volume change curves in other test rotation speed ranges, it determines the test control sequence of the screening rotation speed range. S3 performs test control processing for different screening rotation speed ranges according to the test control sequence. Based on the consistency of the volume change curves in the screening rotation speed ranges and the existing completed screening rotation speed range data, the test control method of the fully automatic soil shrinkage tester in the screening rotation speed ranges that have not yet been tested is determined.

[0006] The beneficial effects of this invention are as follows: Based on the correlation between the volume change curve and other experimental rotation speed ranges, a selection rotation speed range is determined. The aim is to select rotation speed ranges with stable and reliable measurement results from multiple candidate rotation speed ranges as recommended rotation speed ranges for subsequent soil shrinkage tests. Specifically, the selection of rotation speed ranges with stable and reliable measurement results is based on the similarity and stability of measurement results with other rotation speed ranges, which also lays the foundation for further targeted verification.

[0007] By utilizing test process data from rotation speed ranges that meet the volume change curve requirements, and the correlation between these test processes and the volume change curves of other rotation speed ranges, the test control order for the selected rotation speed ranges is determined. Based on the proportion of matching test processes (reflecting internal consistency) and the similarity of these processes to curves in other speed ranges (reflecting cross-range representativeness), a confidence weight value and a stability matching coefficient are calculated. Through multi-level condition judgment, the selected ranges are divided into first, second, and third priorities. The first-priority ranges are tested first, and the high-quality deformation curves they generate provide a benchmark for the reliability assessment of subsequent ranges. When the similarity of the curves of subsequent ranges to these confidence benchmarks is low, their reliability is deemed insufficient, and the test is terminated early, thereby significantly improving overall testing efficiency while ensuring data quality.

[0008] Furthermore, the volume change curve of the soil as the moisture content changes is determined based on the scanning results of a laser or structured light scanner.

[0009] Furthermore, the abnormal variation period in the historical measurement process is determined based on the degree of consistency between the measurement process and the volume variation curve of the historical measurement process in the same test area within the most recent preset period. Specifically, if the number of historical measurement processes in the period that do not meet the consistency requirements is greater than the preset measurement process number threshold, then the period is determined to be an abnormal variation period.

[0010] Furthermore, the method for determining the adjustment strategy of the experimental rotation speed is as follows: S11 Based on the abnormal fluctuation period data, determine the measurement process with abnormal fluctuation period and treat it as an abnormal measurement process; S12 determines the similarity coefficient of abnormal change periods between different abnormal measurement processes based on the degree of overlap of abnormal change periods in different abnormal measurement processes. S13 uses the abnormal measurement process data and the similarity coefficient of the abnormal change periods between different abnormal measurement processes to determine the adjustment strategy for the test rotation speed.

[0011] Furthermore, the method for determining the test control sequence for the selected rotation speed range is as follows: S31 uses the test process data of the volume change curve within the screening rotation speed range that meets the requirements to determine the test process that meets the requirements and uses it as the matching test process. S32 determines the similar rotation speed ranges of the matching test process in different unit time periods based on the correlation between the volume change curves of the matching test process and other test rotation speed ranges. S33 determines the test control sequence for the selection of rotation speed ranges based on the matching test process data and the similar rotation speed ranges in different unit time periods of the matching test process.

[0012] Secondly, the present invention provides a fully automatic soil shrinkage tester, employing the control method of the aforementioned fully automatic soil shrinkage tester, specifically including: Mechanical frame, measurement system, control system, power supply system, and human-machine interaction system; The mechanical frame is a stable test frame made of aluminum alloy profiles, integrating a motor-driven platform to support the sample; the measurement system includes an electronic balance and a deformation measurement unit: the electronic balance is placed below the lifting platform, and the deformation measurement unit measures the soil sample deformation; the control system includes a core controller, a motor drive device, and a data acquisition device; the power supply system is used to supply power to the control system and the measurement system, and the human-machine interaction system uses a touch screen as the display and operation interface.

[0013] Other features and advantages will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0014] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0015] The above and other features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0016] Figure 1 This is a flowchart of a control method for a fully automatic soil shrinkage tester; Figure 2 This is a flowchart illustrating the method for determining the adjustment strategy for the experimental rotation speed; Figure 3 This is a frame diagram of a fully automated soil shrinkage tester. Detailed Implementation

[0017] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0018] The terms “a,” “one,” “the,” and “the” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended meaning of inclusion and that other elements / components / etc. may exist in addition to the listed elements / components / etc.

[0019] Example 1 To solve the above problems, according to one aspect of the present invention, such as Figure 1 As shown, a control method for a fully automatic soil shrinkage tester is provided, specifically including: S1 uses a soil shrinkage tester to determine the volume change curve of soil as moisture content changes, uses the volume change curve to determine the abnormal change period in the historical measurement process, and determines the adjustment strategy of the test rotation speed based on the abnormal change period data and the degree of overlap of the abnormal change period. Furthermore, the volume change curve of the soil as the moisture content changes is determined based on the scanning results of a laser or structured light scanner.

[0020] Furthermore, the abnormal variation period in the historical measurement process is determined based on the degree of consistency between the measurement process and the volume variation curve of the historical measurement process in the same test area within the most recent preset period. Specifically, if the number of historical measurement processes in the period that do not meet the consistency requirements is greater than the preset measurement process number threshold, then the period is determined to be an abnormal variation period.

[0021] Specifically, such as Figure 2 As shown, the method for determining the adjustment strategy of the experimental rotation speed is as follows: By analyzing anomalous periods in historical measurements, the experimental rotation speed is dynamically adjusted to ensure the laser scanning device can reliably monitor soil volume changes with moisture content. The core logic is as follows: First, identify measurement processes with anomalous periods (abnormal measurement processes), and quantify the overlap (similarity coefficient) between different anomalous processes. This allows for the assessment of the reliability of monitoring within different volume change ranges. The assessment results are then used to determine the adjustment strategy for the experimental rotation speed. This mechanism adaptively optimizes the rotation speed, laying the foundation for further improving the reliability of deformation monitoring. Specifically, the adjustment strategy for the rotation speed is determined hierarchically based on the number of anomalous processes, the average similarity coefficient, and the group distribution of anomalous processes. If there are few anomalous processes, a preset step size is used for rapid adjustment; if there are many anomalous processes and they are highly concentrated in the same time period, a smaller step size is used for fine adjustment; if the anomalous processes exhibit multiple patterns (multiple groups), a fine adjustment strategy is also employed.

[0022] S11 Based on the abnormal fluctuation period data, determine the measurement process with abnormal fluctuation period and treat it as an abnormal measurement process; Abnormal fluctuation period: This refers to a continuous period during which, when the curve of soil volume change with moisture content obtained from a laser or structured light scanner during a certain measurement process, does not meet the preset requirements for consistency compared with the volume change curve of the same test area within the most recent preset period (e.g., 10 measurements within the last 3 days). The degree of consistency can be quantified by indicators such as the correlation coefficient and root mean square error between curves. If the degree of consistency of a certain period is lower than the threshold, that period is marked as an abnormal fluctuation period.

[0023] Abnormal measurement process: If a complete soil shrinkage measurement process includes at least one time period marked as an abnormal variation period, then the measurement process is defined as an abnormal measurement process.

[0024] Rotation speed directly affects the quality of point cloud data acquired by the scanner: excessive speed may lead to sparse or blurred scan points, while excessively slow speed may cause deformation errors due to continuous soil sample shrinkage. By identifying periods of abnormal variation, the scanner quality degradation that may be caused by improper rotation speed in specific measurement stages can be pinpointed. Marking the entire measurement process containing these abnormal periods as an abnormal measurement process facilitates subsequent focused analysis of anomalies, eliminates interference from random factors, and provides a reliable historical data basis for adjusting the rotation speed.

[0025] In a rotational speed optimization process, the main control module retrieves the volume change curves from the most recent 20 measurement processes, using the average shape of the most recent 5 measurement curves as a benchmark. For each measurement, its curve is compared with the benchmark curve for each moisture content interval (unit time period). A consistency threshold is set (correlation coefficient not less than 0.85). If the correlation coefficient of a measurement process in the moisture content range of 15%~12% is only 0.60, then this interval is marked as an abnormal fluctuation period, and this measurement process is identified as an abnormal measurement process.

[0026] S12 determines the similarity coefficient of abnormal change periods between different abnormal measurement processes based on the degree of overlap of abnormal change periods in different abnormal measurement processes. Similarity coefficient for abnormal fluctuation periods: This coefficient quantifies the degree of overlap between abnormal fluctuation periods in two abnormal measurement processes along a time axis (such as a moisture content interval or a test time interval). The coefficient can be calculated based on the ratio of the overlap duration (or the length of the moisture content interval) to the total duration; for example, similarity coefficient = overlap duration / union duration, with a value ranging from 0 to 1. In practical implementations, a preset scaling factor can also be introduced to weight the number of overlaps.

[0027] The degree of overlap in periods of abnormal fluctuations reflects whether the anomaly occurs repeatedly in the same contraction phase (e.g., the transition phase between normal and residual contraction). If multiple measurement processes exhibit anomalies in the same phase, it suggests that this phase is particularly sensitive to the current rotational speed and requires fine-tuning; if the anomalies are dispersed, they may be caused by random errors or other factors. The introduction of a similarity coefficient provides a mathematical basis for quantifying this correlation, facilitating subsequent decision-making.

[0028] Suppose there are two abnormal measurement processes P1 and P2. The abnormal fluctuation period of P1 is 18%~15% moisture content (length 3%), and the abnormal fluctuation period of P2 is 15%~12% (length 3%). The overlap between the two is 15%~15% (length 0), so the similarity coefficient is 0. If P1 is 18%~15% and P3 is 18%~15%, then the overlap length is 3%, the union length is 3%, and the similarity coefficient is 1.

[0029] S13 uses the abnormal measurement process data and the similarity coefficient of the abnormal change periods between different abnormal measurement processes to determine the adjustment strategy for the test rotation speed.

[0030] It should be noted that the similarity coefficient of the abnormal change periods between the abnormal measurement processes is determined by multiplying the number of overlapping abnormal change periods between the abnormal measurement processes with a preset scaling factor.

[0031] Specifically, using the abnormal measurement process data and the similarity coefficients of abnormal variation periods between different abnormal measurement processes, an adjustment strategy for the test rotation speed is determined, including: S131 Obtain the number of abnormal measurement processes, determine whether the number of abnormal measurement processes is greater than the preset measurement process number threshold. If not, determine that the adjustment strategy of the test rotation speed is to determine the adjustment strategy of the test rotation speed according to the preset step size, so as to determine that the laser scanning device can reliably monitor volume changes in multiple rotation speed ranges. If yes, proceed to step S132. Preset measurement process number threshold: a critical value used to determine whether an anomaly is sporadic. For example, if there are fewer than 3 anomalies in the last 20 measurements, the anomaly is considered to be likely caused by random factors, and no overreaction is necessary.

[0032] Preset step size: The baseline rotational speed adjustment range, for example, ±0.5 rpm per adjustment. This step size is suitable for situations with few abnormal processes, allowing for a faster search for a suitable rotational speed range with a larger range.

[0033] First, an initial screening is performed based on the number of abnormal processes to exclude low-probability events and avoid unnecessary adjustments for occasional anomalies. If the number of abnormal processes does not exceed the threshold, a standard adjustment step size is adopted, which ensures adjustment efficiency while simplifying the control logic and quickly exploring the reliability of scanning at different speed ranges.

[0034] The current rotation speed is 5 revolutions per minute. The number of abnormal measurement processes in the last 20 measurements is 2. The preset threshold for the number of measurement processes is 3. Since 2 ≤ 3, the preset step size of 0.5 revolutions per minute is used for adjustment to obtain the deformation measurement results at different rotation speeds.

[0035] S132 uses the similarity coefficient of the abnormal variation period between different abnormal measurement processes to determine the average value of the similarity coefficient of the abnormal variation period between different abnormal measurement processes. It then determines whether the average value of the similarity coefficient of the abnormal variation period between different abnormal measurement processes is greater than the preset similarity coefficient threshold. If so, it indicates that the measurement results are frequently abnormal in the same period. Therefore, the measurement reliability based on the current rotation speed is not good. Thus, the adjustment strategy for the test rotation speed is determined to be determined according to the second preset step size. If not, proceed to step S133. Average similarity coefficient: The average similarity coefficient between each pair of all abnormal measurement processes is taken to characterize the consistency level of the overall abnormal period.

[0036] Preset similarity coefficient threshold: A critical value used to determine when abnormal periods are highly concentrated. For example, if the threshold is set to 0.6, an average value higher than this means that most abnormalities are concentrated in the same period.

[0037] Second preset step size: An adjustment range different from the preset step size. Usually, a smaller step size (such as ±0.2 rpm) is used for fine adjustment to avoid skipping the optimal rotation speed point due to an excessively large step size.

[0038] When there are numerous abnormal processes and the abnormal periods highly overlap, it indicates that the current rotation speed is causing a systematic deviation in the scan data at a specific stage, requiring careful fine-tuning. Using a smaller second preset step size allows for detailed exploration near this sensitive stage, improving the accuracy of speed optimization while preventing large adjustments from introducing new uncertainties.

[0039] Five abnormal measurement processes were set up, with pairwise similarity coefficients of 0.9, 0.8, 0.7, 0.6, and 0.5, respectively, and an average value of 0.7. The preset similarity coefficient threshold was 0.6, and since 0.7 > 0.6, a second preset step size of 0.2 revolutions per minute was used for fine adjustment.

[0040] S133 divides abnormal measurement processes with similarity coefficients greater than a preset similarity coefficient threshold into the same group, and determines the adjustment strategy for the test rotation speed based on the number of groups.

[0041] Specifically, if the number of groups is greater than a preset group number threshold, the adjustment strategy for the test rotation speed is determined to be determined according to a second preset step size; otherwise, the adjustment strategy for the test rotation speed is determined to be determined according to a preset step size, wherein the preset step size is greater than the second preset step size.

[0042] Cluster: Through cluster analysis, abnormal measurement processes with similarity coefficients higher than the threshold are grouped together. The processes within the group have similar abnormal time period characteristics. Number of groups: The number of different groups formed after clustering.

[0043] If the number of groups is greater than the preset group number threshold, the adjustment strategy for the test rotation speed is determined to be based on the second preset step size; When there are many anomalous processes but a low average similarity coefficient, it may indicate the existence of multiple distinct anomalous patterns (e.g., anomalous events occurring at different stages). In this case, using a fixed small step size may be inefficient, while using a large step size might miss some patterns. Through group analysis, if multiple groups (i.e., multiple anomalous patterns) exist, the problem is complex, and a cautious approach of using small step sizes for gradual exploration is still advisable; if only a few groups exist, a large step size can be used for rapid adjustment. This logic further refines the decision-making granularity, making the rotation speed adjustment strategy more closely aligned with the actual anomalous distribution.

[0044] There are 6 abnormal measurement processes. After calculating their similarity coefficients, they are divided into two groups: Group A contains processes P1, P2, and P3 (all with similarity coefficients > 0.6), and Group B contains P4 and P5 (similarity coefficients > 0.6). P6 is isolated and does not form a group. The number of groups is 2, and the preset threshold for the number of groups is 1. Since 2 > 1, a second preset step size is used for fine adjustment.

[0045] This invention achieves intelligent and precise adjustment of experimental rotation speed by introducing abnormal variation period identification, similarity coefficient calculation, and multi-level decision-making logic. Its core value lies in: Improving the quality of scanning data: Adjusting the rotation speed based on historical anomaly statistics can effectively avoid point cloud sparsity, motion blur or deformation errors caused by improper rotation speed, ensuring that the laser scanning device can reliably monitor soil volume changes.

[0046] Enhanced equipment adaptability: Without manual intervention, the system can automatically optimize rotation speed parameters based on actual measurement results, adapting to changes in different soil sample types or shrinkage stages, thus improving the instrument's automation level and versatility.

[0047] Optimize test efficiency: By differentiating the degree of anomaly concentration, and rationally selecting large or small step size adjustments, the test cycle can be shortened and the number of repeated measurements reduced while ensuring accuracy.

[0048] Provides explainable decision-making basis: the logic of each step is clear, and the threshold can be set based on experience or prior knowledge, which is convenient for users to understand and for system debugging, and also lays the foundation for subsequent machine learning optimization.

[0049] The scientific nature of the multi-level decision-making mechanism: By progressively judging the number of abnormal processes, the average similarity coefficient, and the number of groups, it takes into account both the overall scale of the anomaly and the diversity and concentration of the anomaly patterns, making the adjustment strategy more robust and reliable.

[0050] S2 uses the adjustment strategy to adjust the test rotation speed. Based on the correlation between the volume change curve and other test rotation speed ranges, it determines the screening rotation speed range in the test rotation speed range. Using the test process data where the volume change curve in the screening rotation speed range meets the requirements, and combining the correlation between the test process where the volume change curve meets the requirements and the volume change curves in other test rotation speed ranges, it determines the test control sequence of the screening rotation speed range. Specifically, the method for determining the screening rotation speed range within the experimental rotation speed range is as follows: This invention aims to select rotation speed ranges with stable and reliable measurement results from multiple candidate rotation speed ranges as recommended rotation speed ranges for subsequent soil shrinkage tests. Specifically, the selection is based on the similarity and stability of measurement results with other rotation speed ranges, laying the foundation for further targeted verification. The core logic is to quantify the consistency between each rotation speed range and other rotation speed ranges by comparing the morphological similarity of the soil volume change curves (i.e., volume variation curves) at various shrinkage stages (unit time periods) under different rotation speed ranges. Based on the distribution characteristics of consistency over time, combined with multi-level threshold judgments, it is ultimately determined whether the rotation speed range belongs to the selected range. This selection process can eliminate speed ranges with abnormal scanning data or poor measurement stability due to inappropriate rotation speeds, laying the foundation for further targeted selection of rotation speed ranges for deformation monitoring.

[0051] S21 determines the curve similarity coefficient of the volume change curve between the test rotation speed range and other test rotation speed ranges in different unit time periods based on the correlation between the volume change curve and other test rotation speed ranges. Volumetric variation curve: This refers to the relationship between soil volume and moisture content, acquired in real time using a laser or structured light scanner within a specific experimental rotation speed range. It reflects the entire process of soil shrinkage. The rotation speed directly affects the density and uniformity of the scanned point cloud, thus affecting the smoothness and accuracy of the volumetric variation curve.

[0052] Test rotation speed range: A continuous speed range divided for rotation speed screening, such as 4-5 rpm, 5-6 rpm, etc. Multiple repeated tests are conducted within each range to obtain a representative curve.

[0053] Unit time period: The moisture content range (or time range) of the entire contraction process is divided into several continuous small intervals, each interval is called a unit time period, which is used to compare the curve shape segment by segment.

[0054] Curve similarity coefficient: an index that quantitatively describes the similarity of the shape of the volume change curves of two rotation speed ranges within the same unit time period. It is usually calculated using correlation coefficient, cosine similarity, or dynamic time warping distance, etc. The larger the value, the closer the curve shape is.

[0055] The impact of rotation speed on scan quality can vary at different shrinkage stages: in the rapid shrinkage stage, excessively high rotation speeds may lead to sparse point clouds or motion blur; in the slow shrinkage stage, excessively low speeds may prolong the scan cycle. By comparing the curve shape segment by segment, the impact of rotation speed on the scan data quality at each stage can be captured, avoiding the overall averaging from masking local anomalies. The introduction of curve similarity coefficients provides a quantitative basis for subsequent screening, allowing the consistency between different rotation speed ranges to be objectively measured.

[0056] In one screening experiment, five rotation speed ranges R1 to R5 were involved. The process of reducing the moisture content from 30% to 10% was divided into 10 time periods D1 to D10, each corresponding to a 2% moisture content range. For the target rotation speed range R3, the curve similarity coefficients between R3 and R1, R2, R4, and R5 were calculated for each time period D1 to D10. For example, in time period D1, the similarity coefficient between R3 and R1 was 0.92, indicating that the volume change curves of the two were highly consistent in this stage.

[0057] S22 uses the curve similarity coefficient to determine the similar rotation speed ranges of the test rotation speed range in different unit time periods; Similar rotational speed range: For a target rotational speed range, if the curve similarity coefficient between it and another rotational speed range is greater than the preset volume change similarity coefficient threshold within a certain unit time period, then the other rotational speed range is called the similar rotational speed range of the target rotational speed range in that time period.

[0058] Preset volume variation similarity coefficient threshold: A pre-set critical value used to determine whether two curves are sufficiently similar. It is usually set according to the experimental accuracy requirements, such as 0.8 or 0.9.

[0059] Determining similar rotational speed ranges transforms continuous similarity coefficients into discrete judgment results, facilitating subsequent statistical analysis. Through threshold filtering, other speed ranges with consistent scan quality to the target rotational speed range can be identified at each contraction stage. These ranges constitute the "support set" for the target rotational speed range at that stage, reflecting the data reliability of that speed at the corresponding stage.

[0060] Following the previous example, we set the preset volume change similarity coefficient threshold to 0.8. For R3 in time period D1, its similarity coefficient with R1 (0.92) and its similarity coefficient with R2 (0.85) are both greater than 0.8. Therefore, the similar rotational speed range of R3 in time period D1 includes R1 and R2. In time period D6, R3 only has a similarity coefficient with R4 (0.88) greater than 0.8. Therefore, the similar rotational speed range is only R4.

[0061] S23 determines whether the test rotation speed range belongs to the screening rotation speed range based on the similar rotation speed ranges in different unit time periods of the test rotation speed range.

[0062] It should be noted that the similarity coefficient of the volume change curves of the test rotation speed range and other test rotation speed ranges in different unit time periods is determined based on the identification results of the curve correlation coefficient, cosine similarity, etc. of the volume change curves in the unit time period.

[0063] Specifically, the similar rotational speed range within a unit time period is the test rotational speed range whose similarity coefficient with the volume change curve of the test range is greater than a preset volume change similarity coefficient threshold within the unit time period.

[0064] It is understood that, based on similar rotational speed intervals within different unit time periods, determining whether the test rotational speed interval belongs to the screening rotational speed interval specifically includes: S231 uses similar rotation speed intervals in different unit time periods to determine the unit time periods with similar rotation speed intervals and uses them as similar unit time periods. The basic confidence value of the test rotation speed interval is determined by the proportion of the similar unit time periods in the unit time period. It is then determined whether the basic confidence value of the test rotation speed interval meets the requirements. If yes, proceed to step S232. If no, it is determined that the test rotation speed interval does not belong to the screening rotation speed interval. Similar unit time period: If there is at least one similar rotation speed range in a certain time period among all the unit time periods of a certain target rotation speed range, then the time period is called a similar unit time period.

[0065] Baseline confidence value: The proportion of similar time intervals to the total number of time intervals. It measures the coverage of supported velocity intervals within the target rotation velocity range during the overall contraction process. A higher proportion indicates that the velocity is consistent with the scan results of other velocity intervals in more stages, and the baseline confidence value is higher.

[0066] If no similar intervals are found for a given rotational speed range during most of the contraction phase, it indicates that the overall scan quality is unique, possibly due to data distortion caused by improper speed settings, and should be excluded. Preliminary screening using baseline confidence values ​​can quickly filter out speed ranges with excessively low coverage, simplifying subsequent analysis.

[0067] Assuming that R3 has at least one similar rotational speed interval in each of the 10 time units, the number of similar time units is 10, accounting for 100%, and the basic confidence value is 1.0. Setting the basic confidence value requirement to be no less than 60%, 1.0 meets the requirement, and we proceed to the next step.

[0068] S232 Obtain the number of similar rotation speed intervals in different similar unit time periods, and determine whether the number of similar rotation speed intervals in different similar unit time periods is greater than the preset rotation speed interval number threshold. If yes, determine that the test rotation speed interval belongs to the screened rotation speed interval. If no, proceed to step S233. Preset rotational speed range number threshold: A pre-defined integer threshold used to determine whether there are enough other speed ranges similar to the target rotational speed range in each similar unit time period. This threshold reflects the requirement for supporting diversity.

[0069] "All greater than": This requires that the number of similar rotation speed intervals in each similar unit time period exceeds the threshold.

[0070] If a rotational speed range has only a very few (or even one) similar speed ranges in certain time periods, it may mean that the similarity in these time periods is accidental, or that the speed is only similar to a specific range and lacks broad representativeness. Requiring the number of similar speeds in each time period to be greater than a threshold ensures that the target rotational speed is adequately supported in all stages, thereby improving the reliability of the screening.

[0071] Let the preset threshold for the number of rotation speed intervals be 2. For R3, there are 2 similar intervals (R1, R2) in time period D1, 2 in D2, 3 in D3, 2 in D4, and 2 in D5, but only 1 in D6, 1 in D7, 1 in D8, 1 in D9, and 1 in D10. Since the number of similar intervals in multiple time periods is not greater than 2, the condition of "all greater than" is not met, so proceed to the next step.

[0072] S233 Determine whether the average number of similar rotation speed intervals in different similar unit time periods is greater than the preset rotation speed interval number threshold. If not, determine that the test rotation speed interval does not belong to the screened rotation speed interval. If yes, proceed to step S234. Average: The arithmetic mean of the number of similar rotation speed intervals across all similar time periods is used to measure the overall support average level.

[0073] When the number of similar intervals is small in certain periods but the overall average is high, it indicates that although the support is insufficient in individual periods, the overall support is still acceptable. In this case, it should not be ruled out directly, but further analysis is required. This step, as a supplement to the "all greater than" condition, allows for a certain degree of fluctuation, but requires that the overall average level meets the standard.

[0074] Calculate the average number of similar rotation speed intervals for all 10 time periods of R3: (2+2+3+2+2+1+1+1+1+1) / 10 = 1.6. Since 1.6 is less than the preset threshold of 2, the average value does not meet the requirement of being greater than the threshold. Therefore, R3 is determined not to belong to the selected rotation speed interval. If the average value is greater than the threshold, proceed to the next step.

[0075] S234 determines the comprehensive confidence value of the test rotation speed interval by taking into account the proportion of similar unit time periods in which the number of similar rotation speed intervals is greater than the preset threshold number of rotation speed intervals, and combining this with the basic confidence value of the test rotation speed interval. It then determines whether the comprehensive confidence value of the test rotation speed interval meets the requirements. If yes, the test rotation speed interval is determined to belong to the screening rotation speed interval; otherwise, the test rotation speed interval is determined not to belong to the screening rotation speed interval.

[0076] Percentage of similar time units with a number greater than the threshold: Among similar time units, the proportion of time periods in which the number of similar rotation speed intervals exceeds the preset threshold.

[0077] Comprehensive confidence value: A comprehensive index obtained by combining the basic confidence value with the above proportions. It can be expressed in the form of product or weighted sum, and is used to more precisely measure the overall confidence level of the target rotation speed range.

[0078] Overall confidence value requirement: A pre-set threshold value must be reached for the overall confidence value to be determined as a screening rotation speed range.

[0079] When the overall average meets the standard but support is insufficient in certain periods, the proportion of periods with insufficient support needs further evaluation. If the proportion of periods with sufficient support is high, it indicates that most periods have broad support, and the insufficiency in a few periods may be caused by random factors and is still acceptable. The overall confidence score combines the proportion of coverage (basic confidence score) and deep support, making the screening criteria more comprehensive.

[0080] Suppose that the data for another rotation speed interval R2 satisfy the condition that the average value is greater than the threshold of 2 (e.g., the average value is 2.5), and its base confidence value is 1.0 (similar intervals exist in all time periods). Calculate the percentage of time periods where the number of similar rotation speed intervals is greater than the threshold. For example, if 8 out of 10 time periods have more than 2 similar intervals, the percentage is 0.8. Let the overall confidence value be the product of the base confidence value and the percentage (1.0 × 0.8 = 0.8). The overall confidence value requirement is 0.7. Since 0.8 > 0.7, R2 belongs to the selected rotation speed intervals.

[0081] This invention achieves automated screening and evaluation of experimental rotation speed ranges by introducing curve similarity coefficients, similar rotation speed ranges, multi-level threshold judgment, and comprehensive confidence value calculation. Based on the statistical similarity of measurement data, rather than subjective experience, the most representative rotation speed ranges are selected, reducing human bias. The selected rotation speed ranges show high consistency with other speed ranges at different contraction stages, ensuring that the volume change curves obtained at these speeds have universal significance and facilitate comparative analysis between different experiments.

[0082] After automatically selecting stable and reliable speed ranges, key tests can be conducted within these ranges to avoid wasting resources under abnormal or unstable speed conditions and improve test efficiency. By using progressively progressive judgment conditions such as basic confidence value, time period satisfaction, average value, and comprehensive confidence value, both the breadth of coverage and the depth of support are considered, avoiding the one-sidedness of a single indicator and making the screening results more robust and reliable.

[0083] This invention aims to prioritize screening rotation speed ranges to ensure that the most reliable and stable speed ranges are tested first. Its core objective is to provide reliable deformation curve references for subsequent screening ranges that have not yet been tested, thereby enabling the rapid identification and timely termination of tests for speed ranges with lower reliability in later tests, avoiding resource waste and improving overall testing efficiency.

[0084] It should be noted that the method for determining the experimental process in which the volume change curve meets the requirements is as follows: The core logic consists of two phases: First, within each selected rotational speed range, cluster analysis identifies test processes (matching test processes) whose volume change curves meet the requirements. These processes represent the most typical and reliable shrinkage behavior within that range. Second, based on the proportion of matching test processes (reflecting internal consistency) and the similarity of these processes to curves in other speed ranges (reflecting cross-range representativeness), a confidence weight value and a stability matching coefficient are calculated. Multi-level conditional judgments then divide the selected ranges into first, second, and third priorities. First-priority ranges are tested first, and the resulting high-quality deformation curves provide a benchmark for the reliability assessment of subsequent ranges. When the similarity between the curves of subsequent ranges and these confidence benchmarks is low, their reliability is deemed insufficient, and the test is terminated early, thereby significantly improving overall testing efficiency while ensuring data quality.

[0085] A crucial prerequisite: all experiments involved in the analysis must use standardized soil samples collected from the same location and prepared in the same batch to ensure complete consistency in the intrinsic properties of the soil samples (mineral composition, particle size distribution, structural characteristics, initial dry density, initial moisture content, etc.). Only under this premise can differences in volume variation curves be attributed to variations in experimental conditions such as rotation speed, and only then will subsequent statistical analysis have physical meaning. If differences exist in the soil samples themselves, the source of the curve differences cannot be decoupled, and all judgments regarding similarity, confidence weights, and priorities will lose their scientific basis.

[0086] Based on the similarity coefficient of the volume change curves between different test processes within the aforementioned rotation speed range at different unit time intervals, test processes that meet the requirements for the similarity coefficient of their volume change curves at all unit time intervals are grouped into the same test process group. The test process in the group with the largest number of test processes is selected as the test process whose volume change curve meets the requirements.

[0087] Experimental procedure: This refers to a complete soil shrinkage measurement conducted within a specific rotation speed range, recording the volume change curve from saturation to drying. Since soil samples have consistent characteristics, the differences in curves between different experimental procedures mainly reflect the influence of random errors and experimental conditions.

[0088] Unit time period: The moisture content range of the entire shrinkage process is divided into several continuous small intervals, each interval is called a unit time period, which is used to compare the curve shape in segments in order to capture the effect of rotation speed on different shrinkage stages.

[0089] Similarity coefficient of volume change curves: an index that quantitatively describes the similarity of the shape of volume change curves of two experimental processes within the same unit time period. It is usually calculated using the correlation coefficient. The larger the value, the closer the curve shape is.

[0090] Experimental process groups: Through cluster analysis, experimental processes that meet the preset requirements (e.g., all are greater than a certain threshold) in similarity coefficients across all time periods are grouped together, and the processes within the group exhibit highly consistent contraction behavior.

[0091] Test processes that meet the requirements for volume change curves: Within a certain rotational speed range, those test processes that belong to the largest group of test processes represent the most typical and reliable shrinkage curve shape within that speed range.

[0092] Repeated experiments within the same rotational speed range may produce curve fluctuations due to small random errors. By clustering highly similar experimental processes throughout, the dominant contraction pattern within that speed range can be identified. The largest group represents the most prevalent and stable experimental results. Defining the process within this group as a satisfactory experimental process can effectively eliminate interference from outliers or abnormal experiments, providing a reliable data foundation for subsequent analysis.

[0093] Ten repeated experiments (Q1 to Q10) were conducted within the rotational speed range R2. The entire contraction process was divided into 10 time intervals D1 to D10, and the curve similarity coefficient between any two experimental processes was calculated across all time intervals. A similarity coefficient of at least 0.85 was set; if the similarity coefficients of two processes were ≥0.85 across all 10 time intervals, they were grouped into the same group. The clustering results formed three groups: Group A contained Q1, Q2, Q3, Q4, and Q5 (5 processes in total); Group B contained Q6, Q7, and Q8 (3 processes); and Group C contained Q9 and Q10 (2 processes). Group A had the most processes; therefore, the five experimental processes Q1 to Q5 were selected as the experimental processes whose volume change curves met the requirements within the R2 range (i.e., the matched experimental processes). The more matched experimental processes, the higher the stability within the stated rotational speed range.

[0094] Furthermore, the method for determining the test control sequence for the selected rotation speed range is as follows: S31 uses the test process data of the volume change curve within the screening rotation speed range that meets the requirements to determine the test process that meets the requirements and uses it as the matching test process. Matching test process: refers to those test processes within a certain screening rotation speed range where the volume change curves selected through the first-stage method meet the requirements. These are the most reliable and representative test results within that speed range.

[0095] Clearly defining the concept of the matching test process provides a foundation for subsequent calculations of its quantity proportion, credibility weight, and other indicators. The matching test process represents a trustworthy data source within this speed range, and subsequent priority determinations will revolve around these processes.

[0096] Continuing from the previous example, for the selection of rotational speed range R2, the matching test process consists of 5 steps: Q1, Q2, Q3, Q4, and Q5.

[0097] S32 determines the similar rotation speed ranges of the matching test process in different unit time periods based on the correlation between the volume change curves of the matching test process and other test rotation speed ranges. Other test rotation speed ranges: These refer to alternative or screening speed ranges besides the current screening rotation speed range, such as R1, R3, R4, R5, etc. These ranges are also based on the same soil sample, so the differences in the curves only reflect the differences in speed conditions.

[0098] Similar rotational speed range: For a certain matching test process, if the similarity coefficient between the volume change curve of the process and the typical curve in another rotational speed range (e.g., the average curve of the matching test process in this range) is greater than a preset threshold within a certain unit time period, then this other speed range is called the similar rotational speed range of the matching test process in this time period.

[0099] A curve from a matching experiment is not only representative within its own speed range but may also exhibit similarities to typical curves in other speed ranges. This cross-range similarity reflects the reliability of the contraction behavior represented by the process. If it aligns with multiple rotational speed ranges, it indicates that the measurement results are independent of rotational speed, thus demonstrating higher reliability. By identifying similar speed ranges corresponding to each matching process at different time points, its consistency with the overall experimental system can be quantified, providing a basis for subsequent calculations of reliability weights.

[0100] For the matching test process Q1 of R2, its volume change curve is compared with the average curve of the matching test process in each interval of R1, R3, R4, and R5. The similarity coefficient is calculated for each time period from D1 to D10. A preset volume change similarity coefficient threshold of 0.8 is set to obtain the similar rotation speed intervals of Q1 in each time period: for example, the time period D1 is similar to R1 and R3, and the time period D2 is similar to R1, R3, and R4, etc.

[0101] S33 determines the test control sequence for the selection of rotation speed ranges based on the matching test process data and the similar rotation speed ranges in different unit time periods of the matching test process.

[0102] It is understood that if the proportion of the number of matching test processes within the screening rotation speed range is greater than the preset matching test process proportion threshold, then the test control order of the screening rotation speed range is determined to be the first priority.

[0103] The proportion of matching test processes: Within a certain screening rotation speed range, the proportion of matching test processes to the total number of test processes in that range (including tests that do not meet the requirements).

[0104] Preset matching test process percentage threshold: A pre-set critical value used to determine the concentration of reliable tests within this range. A high percentage indicates that most test results within this speed range are consistent and have high stability.

[0105] If most test procedures within a speed range conform to the mainstream pattern (i.e., a high proportion of matched test procedures), it indicates good repeatability and minimal impact from random factors at that speed setting, and should be given priority. Therefore, it is directly assigned the highest priority. Such a range will be tested first, and the high-quality deformation curves generated can provide a benchmark for the reliability assessment of subsequent ranges.

[0106] Additionally, it should be noted that if the proportion of the number of matching test processes within the screening rotation speed range is not greater than a preset threshold for the proportion of matching test processes, the following situations also apply: Case 1: The confidence weight value of the matching test process is determined by the average number of similar rotation speed intervals in different unit time periods. If there is no matching test process with a confidence weight value greater than the preset weight threshold, the test control order of the selected rotation speed interval is determined to be the third priority.

[0107] Number of similar rotational speed intervals: For a matched experimental process, the total number of similar rotational speed intervals it has in all unit time periods (or the average number per time period) is counted, reflecting the breadth of consistency between the process and other speed intervals.

[0108] Credibility weight: An index calculated based on the number of similar rotational speed intervals, used to measure the cross-interval representativeness of a matched trial process. The larger the number, the more similar the contraction behavior of the process is to the typical behavior of more other speed intervals, and the higher the credibility.

[0109] Preset weight threshold: A pre-defined critical value used to determine whether the matching experiment process has sufficient cross-interval representativeness.

[0110] If a matching test process exists within a speed range, but the curves of these processes show low similarity to other speed ranges (low confidence weight), it indicates that the contraction behavior of this speed range is relatively isolated and inconsistent with other rotational speed ranges, thus its confidence level is low. In this case, the reference value of this range is limited, and its deformation curve is difficult to use as a reliable benchmark for subsequent ranges. Therefore, it should be placed with the lowest priority (third priority) and tested last or used only as a reference.

[0111] Scenario 2: When there is a matching test process with a confidence weight value greater than the preset weight threshold, the stable matching coefficient of the screening rotation speed range is determined by the average confidence weight value of different matching test processes and the proportion of the number of test processes in the screening rotation speed range. When the stable matching coefficient of the screening rotation speed range is greater than the preset stable matching coefficient threshold, the test control order of the screening rotation speed range is determined to be the first priority.

[0112] Mean of credible weight values: The arithmetic mean of the credible weight values ​​of all matching test processes within the speed range reflects the overall cross-range representativeness of the matching process within that range.

[0113] Stable matching coefficient: A comprehensive index obtained by combining the mean of the credible weight values ​​with the proportion of the number of matching test processes. For example, it can be defined as the product or weighted sum of the two, and is used to measure the overall stability and representativeness of the speed range.

[0114] Preset stable matching coefficient threshold: A pre-set critical value used to determine whether the speed range is stable and reliable enough, and can be directly assigned the first priority.

[0115] When a velocity range contains credible matching processes (with some processes exceeding the threshold) and exhibits a high overall average level and proportion, it indicates that the velocity range not only has good internal consistency but also exhibits a wide range of contraction behaviors similar to other velocity ranges, demonstrating high universality and stability. Such a range is the ideal benchmark source and should be the first choice, directly assigned the highest priority.

[0116] Case 3: When the stable matching coefficient of the screening rotation speed range is not greater than the preset stable matching coefficient threshold, if the average value of the confidence weight values ​​of different matching test processes is greater than the preset weight threshold, then the test control order of the screening rotation speed range is determined to be the first priority; otherwise, it belongs to the second priority.

[0117] It should be noted that the first priority is greater than the second priority, and the second priority is greater than the third priority. Within a screening rotation speed range of a priority range, the test control order is determined by the proportion of the number of test processes in the screening rotation speed range of the matching test process. This fully considers the reliability and stability of the detection, thereby providing a more reliable volume change curve for the subsequent screening rotation speed range and laying the foundation for further determination of the usable test rotation speed range.

[0118] When the comprehensive index (stable matching coefficient) does not reach the level to be directly assigned first priority, the mean itself is further examined. If the mean is still high (exceeding the weight threshold), it indicates that although the proportion of numbers is not high or the comprehensive index is slightly low, the overall cross-interval representativeness of the matching process is still good, and it can still be assigned first priority because its curve still has the potential to serve as a benchmark. If the mean also does not meet the standard, it indicates that the performance of this speed interval is at an intermediate level, neither completely isolated like the third priority nor as prominent as the first priority, so it is classified as second priority and can be tested after the first priority interval.

[0119] It should be noted that the first priority is greater than the second priority, and the second priority is greater than the third priority. For a screening rotation speed range within a priority range, the test control order is determined by the proportion of the number of test processes in the screening rotation speed range of the matching test process.

[0120] Within the same priority level, there may be multiple speed ranges. In this case, they are sorted by the proportion of matching test processes, with the ranges having the highest proportion taking priority. This ensures that, under the same level of representativeness, ranges with better internal consistency are prioritized, further optimizing the test sequence.

[0121] This invention prioritizes the most reliable and stable rotational speed ranges for testing, and the resulting reliable deformation curves provide a benchmark for the reliability assessment of subsequent ranges. When the curves of subsequent ranges show little similarity to these reliable benchmarks, the system can quickly determine that their reliability is insufficient and terminate the test early, avoiding wasting time and resources on unreliable speed ranges. By prioritizing reliable benchmarks, the reliability of subsequent ranges can be assessed with only a few tests, and unreliable ranges can be terminated early, significantly shortening the overall testing cycle.

[0122] The high-quality curves of the first priority interval provide a reliable reference standard for the entire test system, ensuring the comparability and interpretability of subsequent interval data, concentrating limited test resources on the most stable and representative speed intervals, and avoiding excessive investment in isolated or abnormal speed intervals.

[0123] In one possible specific embodiment, a fully automated soil shrinkage tester includes a rotatable turntable for sample placement, with adjustable rotation speed. A laser scanner is fixed to the top of the cavity and acquires a three-dimensional point cloud during soil sample rotation. The main control module has a built-in rotation speed optimization and sorting program. After preliminary screening, five rotation speed ranges were identified: R1, R2, R3, R4, and R5. Preliminary tests have been completed for all ranges (10 times per range). Now, it is necessary to determine the test control sequence for these ranges so that subsequent key tests are prioritized in the most reliable ranges, and the results are used to evaluate other ranges.

[0124] Basic experimental settings: All tests used standardized soil samples prepared from the same location and batch, with an initial moisture content of 30% and an initial dry density of 1.50 g / cm³. Ten tests were completed for each velocity range for this priority ranking analysis.

[0125] Unit time period division: The process with a moisture content of 30% to 10% is divided into 10 unit time periods, D1 to D10.

[0126] Phase 1: Determining the experimental procedure (matching experimental procedure) to ensure that the volume change curves within each interval meet the requirements. R1 interval: 10 trials (P1~P10). Calculate the curve similarity coefficient between each pair of trials across all time periods, setting the similarity coefficient requirement to be no less than 0.85. Clustering results: Group A contains P1, P2, P3, P4, P5, and P6 (6 trials); Group B contains P7 and P8 (2 trials); Group C contains P9 and P10 (2 trials). The matched trials are P1~P6, a total of 6 trials, with a matched trial ratio of 6 / 10 = 0.6.

[0127] R2 interval: 10 trials (Q1~Q10). Clustering results: Group A contains Q1, Q2, Q3, Q4, Q5 (5 clusters), Group B contains Q6, Q7, Q8 (3 clusters), and Group C contains Q9, Q10 (2 clusters). The matching trials were Q1~Q5, a total of 5 trials, and the proportion of matching trials = 5 / 10 = 0.5.

[0128] R3 interval: 10 trials (R1~R10). Clustering results: Group A contains R1, R2, R3 (3 clusters), Group B contains R4, R5, R6, R7 (4 clusters), and Group C contains R8, R9, R10 (3 clusters). The matching trials were from R4 to R7, a total of 4 trials, and the proportion of matching trials = 4 / 10 = 0.4.

[0129] R4 interval: 10 trials (S1~S10). Clustering results: Group A contains S1, S2, S3, S4 (4 clusters), Group B contains S5, S6, S7 (3 clusters), and Group C contains S8, S9, S10 (3 clusters). The matching trials were S1~S4, a total of 4 trials, and the proportion of matching trials = 4 / 10 = 0.4.

[0130] R5 interval: 10 trials (T1~T10). Clustering results: Group A contains T1, T2, T3, T4, T5 (5 clusters), Group B contains T6, T7, T8 (3 clusters), and Group C contains T9, T10 (2 clusters). The matching trials were conducted from T1 to T5, a total of 5 trials, and the proportion of matching trials = 5 / 10 = 0.5.

[0131] Phase Two: Determining the test control sequence for each screening rotation speed range: Step S31: The matching test process and proportion of each interval have been obtained as above.

[0132] Step S32: For each matching test process, calculate the similarity coefficient between its typical curves and those of other speed ranges (taking the average curve of each matching test process) at each time period. Set the preset volume change similarity coefficient threshold to 0.8, determine the similar rotational speed ranges for each matching process at each time period, and calculate their confidence weight value (i.e., the average number of similar rotational speed ranges across all time periods). The results are as follows: R1 matching process: mean = 1.9, R2 matching process: mean = 1.84, R3 matching process: mean = 1.05, R4 matching process: mean = 1.1, R5 matching process: mean = 1.62; Step S33: Determine the priority of each filtering interval.

[0133] R1 interval: matching test ratio = 0.6 > 0.55 → directly determine R1 as the first priority.

[0134] R2 interval: The proportion of matched trials = 0.5 < 0.55, which does not meet the condition of direct first priority.

[0135] There are matching processes with a confidence weight value greater than 2.0, i.e., Q1(2.6), Q2(2.5), and Q3(2.4) are all greater than 2.0. Therefore, the stable matching coefficient is calculated as: mean confidence weight (1.84) × proportion of matching trials (0.5) = 0.92 < 1.0.

[0136] Entering Case 3: The stable matching coefficient is not greater than the threshold, but the mean of the credible weight (1.84) is less than the weight threshold (2.0), so R2 belongs to the second priority.

[0137] Priority sorting: First priority: R1 (0.6%) Second priority: Sorted by the proportion of matched trials, R2 (0.5) and R5 (0.5) are tied, but the mean confidence weight of R2 (1.84) is slightly higher than that of R5 (1.62). The sorting can be further refined, or the mean can be used if the proportions are the same. Here, R2 takes precedence over R5. Assume R2 comes first and R5 comes second.

[0138] Third priority: R3 (0.4) and R4 (0.4), sorted by the mean of the confidence weights, R4 (1.1) is slightly higher than R3 (1.05), so R4 takes priority over R3.

[0139] Final test control sequence: First priority: R1, Second priority: R2, R5, Third priority: R4, R3.

[0140] S3 performs test control processing for different screening rotation speed ranges according to the test control sequence. Based on the consistency of the volume change curves in the screening rotation speed ranges and the existing completed screening rotation speed range data, the test control method of the fully automatic soil shrinkage tester in the screening rotation speed ranges that have not yet been tested is determined.

[0141] Furthermore, the method for determining the test control method of the fully automatic soil shrinkage tester within the untested screening rotation speed range is as follows: This invention aims to provide a dynamic test control method for the untested rotation speed range in a fully automated soil shrinkage tester. Its core objective is to intelligently determine the number of tests required for the untested range by utilizing the statistical characteristics of the completed screening ranges (completed ranges), while ensuring data reliability. This avoids over-testing in unreliable speed ranges and ensures sufficient data acquisition in potentially valuable ranges, thereby improving the efficiency of identifying the optimal rotation speed range.

[0142] First, based on the data from completed intervals, the proportion of matching trials (reflecting internal consistency) and the proportion of credible trial processes (reflecting cross-interval representativeness) for each interval are calculated. Then, based on the coverage of completed intervals across all selected intervals and the quality indicators of these intervals (stable completed intervals, credible completed intervals, etc.), a tiered termination strategy for incomplete intervals is determined. When existing baseline information is sufficient and reliable, incomplete intervals only need to complete a basic number of trials, and whether to terminate early depends on their own credibility. When baseline information is insufficient or reliability is questionable, incomplete intervals need to perform more trials (with a preset threshold for the number of trial processes) to accumulate sufficient data for subsequent analysis, thereby providing more reference data for identifying credible trial processes in stable intervals. This dynamic control strategy can concentrate limited experimental resources on the most promising speed intervals, thereby improving overall testing efficiency and the accuracy of optimal interval identification.

[0143] All experiments involved in the analysis must use standardized soil samples collected from the same location and prepared in the same batch to ensure complete consistency in the intrinsic properties of the soil samples. Only under this premise can the differences in curves between different rotational speed ranges be attributed to changes in velocity conditions, and only then will the statistical indicators have physical meaning.

[0144] S41 determines the test process that falls into the test process group with the most test processes based on the consistency of the volume change curves in the screening rotation speed range. The test process that falls into the test process group with the most test processes is used to determine the updated data of the matching test process. The updated data of the matching test process determines the proportion of the matching test process in the screening rotation speed range and uses it as the matching test proportion. The largest group of test processes: Within a certain screening rotation speed range, the largest group obtained through cluster analysis (grouping test processes whose curve similarity coefficients meet the requirements across all time intervals into the same group). The test processes in this group represent the most typical and reliable contraction behavior within that speed range.

[0145] Matching test process: The test process belonging to the largest group mentioned above is the basis for subsequent analysis.

[0146] Matching test percentage: Within a certain screening rotation speed range, the proportion of matching test processes to the total number of all completed test processes within that range.

[0147] The proportion of matched tests reflects the consistency level of test results within a given speed range. A higher proportion indicates better repeatability and more reliable data at that speed setting. This indicator is one of the core bases for subsequently assessing the stability of the range.

[0148] In the screening rotation speed range R2 where the experiment has been completed, a total of 10 experiments were conducted. Clustering revealed that the largest group contained 5 matching experiment processes. Therefore, the proportion of matching experiments in R2 is 5 / 10 = 0.5.

[0149] S42 uses the consistency between the volume change curves of the screening rotation speed range and other screening rotation speed ranges that have been tested in the existing tests to determine whether there are other screening rotation speed ranges in the screening rotation speed range that meet the consistency requirements, and uses them as reliable test processes. Other screening rotation speed ranges: refers to other screening speed ranges that have been tested but are not included in the current analysis range.

[0150] Consistency requirement: For a certain matching test process, its volume change curve is compared with the average curve of the matching test process in other speed ranges at each unit time period. If the similarity coefficient of the curves in all time periods is greater than the preset threshold, then the process is considered to have a high degree of consistency with other ranges.

[0151] Reliable test procedures: Matching test procedures that exhibit high consistency with at least one other completed matching test procedure within a certain screening rotation speed range. These procedures are not only reliable within their own range, but their contraction behavior is also similar to typical behavior in other speed ranges, demonstrating cross-range representativeness.

[0152] The existence of credible experimental processes indicates that the contraction behavior within this speed range is not isolated, but rather corroborates patterns observed under other speed conditions. A higher proportion of such processes suggests that the data within this range is more universal and can serve as a reference. This indicator is used to subsequently assess the reliability of the range.

[0153] For the matching test process Q1 in R2, its curve is compared with the average curve of the matching test processes in each interval of R1, R3, R4, and R5. If the similarity coefficient between Q1 and R1 is ≥0.8 over 10 time intervals, then Q1 is considered consistent with R1 and belongs to the credible test process. All such processes in R2 are counted to obtain the number and proportion of credible test processes.

[0154] Based on the existing experimental data, including the proportion of matching tests in different screening rotation speed ranges and reliable experimental process data, and combined with the existing experimental data on screening rotation speed ranges, S43 determines the test control method for the fully automatic soil shrinkage tester in the screening rotation speed ranges that have not yet been tested.

[0155] Furthermore, the existing completed screening rotation speed range is taken as the completion range. If the proportion of the completion range within the screening rotation speed range is less than the preset completion proportion threshold, then the test control method of the fully automatic soil shrinkage tester in the screening rotation speed range that has not yet been tested is determined to be no test control required, and the test will stop only when the number of test processes reaches the target number of test processes threshold.

[0156] Completed range: The range of rotational speeds for which the test has been completed.

[0157] Completion rate: The proportion of completed intervals out of the total number of all screening rotation speed intervals (including completed and incomplete ones).

[0158] Preset completion percentage threshold: This is a critical value used to determine whether the completed intervals are sufficiently representative. If the percentage is too low, it indicates insufficient overall reference information, and the uncompleted intervals need to be tested in the usual way until the predetermined number is reached.

[0159] Target test process number threshold: The minimum number of tests that should be completed in each speed range under normal circumstances to ensure basic statistical significance.

[0160] When there are few completed intervals, there is a lack of sufficient cross-interval reference information, making it impossible to perform fine-grained control over the incomplete intervals. Therefore, the safest approach is to complete the experiment according to the predetermined target number.

[0161] Furthermore, if the proportion of the completed interval within the screening rotation speed range is not less than a preset completion proportion threshold, the following content is also included: Case 1: When there are no completion intervals where the proportion of matching tests is greater than a preset matching test proportion threshold, or when the proportion of reliable test processes in completion intervals where the proportion of matching tests is greater than the preset matching test proportion threshold is not within the preset proportion range, the following applies: Preset matching test percentage threshold: a critical value used to determine whether a completion interval has sufficient internal consistency. Intervals with a percentage higher than this threshold are called "stable completion intervals".

[0162] Preset quantity percentage range: A pre-defined reasonable range used to determine whether the proportion of credible test processes is at a normal level.

[0163] Stable completion interval: The completion interval in which the proportion of matched tests is greater than the preset threshold for the proportion of matched tests represents a reliable interval with high internal consistency.

[0164] If no interval meets the internal consistency requirement, or even if it does, but the reliability ratio is abnormal, it indicates that the existing reference information is of low quality or contains contradictions, and incomplete intervals need to be treated with more caution.

[0165] The untested rotation speed range is designated as the incomplete rotation speed range. The percentage of credible test processes in the incomplete rotation speed range is determined to be within a preset percentage range. If so, the deformation monitoring results of the fully automatic soil shrinkage tester are considered to be highly reliable. Therefore, the test control method in the incomplete rotation speed range is to stop the test only when the number of test processes reaches a preset test process number threshold. This provides more reference data for identifying credible test processes in the completed range where the percentage of matching test processes is greater than the preset matching test process percentage threshold. The preset target test process number threshold is greater than the target test process number threshold. If not, proceed to the next step. Rotation speed range not yet completed: Screening speed ranges that have not yet been tested.

[0166] Preset test process number threshold: A higher number of tests than the target test process number threshold, used to obtain more data when needed.

[0167] Basic quantity: This usually refers to the threshold of the number of target test processes, that is, the minimum number of times the initial plan for each interval must be completed.

[0168] If the proportion of uncompleted credible test processes for a given interval is within a reasonable range, it indicates that the interval has high credible potential. Even in the absence of external references, it is worthwhile to increase the number of tests to obtain more data, which in turn can provide more references for the credible test process assessment of existing completed intervals.

[0169] The completed intervals where the proportion of matched tests is greater than the preset threshold for the proportion of matched tests are defined as stable completed intervals. It is then determined whether the number of stable completed intervals is greater than the preset threshold for the number of stable intervals. If so, the test control method of the fully automatic soil shrinkage tester in the uncompleted rotation speed interval is determined to be that the test needs to be stopped only when the number of test processes reaches the preset threshold for the number of test processes. The preset threshold for the number of test processes is greater than the target threshold for the number of test processes, thereby providing more reference data for the stable completed intervals for the identification of credible test processes. If not, proceed to the next step. Preset stable interval quantity threshold: a critical value used to determine whether there are enough stable reference sources.

[0170] If multiple stable completion intervals exist, it indicates that the measurement results are relatively stable. However, there are also many stable completion intervals with low reliability. Therefore, there is a greater need to provide more reliable deformation curves in order to obtain deformation curves more comprehensively. Based on this, the number of tests should be increased for incomplete intervals to fully compare with these stable intervals, thereby enriching the basis for determining the reliability of the test process for stable completion intervals.

[0171] If the number of matching test processes within the incomplete rotation speed range exceeds a threshold when the base number is reached, then the incomplete rotation speed range has the potential to become a stable completion range. Therefore, the test control method for the fully automatic soil shrinkage tester within the incomplete rotation speed range is determined to be to stop the test only when the number of test processes reaches a preset threshold, where the preset threshold is greater than the target threshold. If not, the test control method for the fully automatic soil shrinkage tester within the incomplete rotation speed range is determined to stop the test when the base number is reached, provided that the percentage of reliable test processes is not within the preset percentage range.

[0172] Matching process number threshold: A pre-set critical value used to determine whether an incomplete interval shows the potential to become a stable completed interval after a certain number of matching trials. A large number of matching trials indicates good internal consistency and the possibility of developing into a stable interval.

[0173] If, after completing the initial number of tests, the number of matching trials for an incomplete interval exceeds the threshold, it indicates that the interval has good internal consistency and has the potential to become a stable completed interval in the future. Therefore, the number of trials should be increased to fully explore its value. Otherwise, it is sufficient to decide whether to stop after completing the initial number of tests based on its own credibility ratio.

[0174] Case 2: When the percentage of reliable test processes in the completion interval where the percentage of matched tests is greater than the preset percentage threshold is within the preset percentage range, it includes the following: The stable completion interval within the preset quantity percentage range is defined as the reliable completion interval. It is determined whether the percentage of the reliable completion interval among all completion intervals is greater than the preset reliable interval percentage threshold. If so, the test control method of the fully automatic soil shrinkage tester in the uncompleted rotation speed interval is determined to be that when the basic quantity is reached, the test is stopped as long as the percentage of the reliable test process is not within the preset quantity percentage range. If not, the test control method of the fully automatic soil shrinkage tester in the uncompleted rotation speed interval is determined to be that the test needs to be stopped only when the number of test processes reaches the preset test process number threshold, wherein the preset test process number threshold is greater than the target test process number threshold.

[0175] Credible completion interval: In the stable completion interval, those intervals in which the proportion of credible test processes is within the preset range represent high-quality reference sources that are both stable and representative across intervals.

[0176] Preset confidence interval percentage threshold: a critical value used to determine whether a confidence completion interval dominates the completion interval.

[0177] If the proportion of credible completed intervals is high, it indicates that the reference information is of excellent quality and consistent. For incomplete intervals, it is only necessary to dynamically decide whether to stop based on their own credibility ratio after the basic number of intervals, because there are already sufficient reliable references. If the proportion is not high, it is still necessary to increase the number of experiments to accumulate more data.

[0178] A fully automated soil shrinkage testing instrument features a rotatable sample placement platform with adjustable rotation speed. A laser scanner, fixed to the top of the cavity, acquires three-dimensional point clouds during soil sample rotation. The main control module incorporates a test control strategy generation program. After preliminary screening, five rotation speed ranges were identified: R1, R2, R3, R4, and R5. Tests for R1, R2, and R3 have been completed, while R4 and R5 have not yet been tested. The next step is to determine the test control methods for R4 and R5 based on the data from the completed ranges to improve the efficiency of identifying the optimal rotation speed range.

[0179] Basic experimental settings: All tests used standardized soil samples prepared from the same location and batch, with an initial moisture content of 30%, an initial dry density of 1.50 g / cm³, and completely consistent mineral composition and particle size distribution.

[0180] The plan is to complete at least 10 tests in each speed range (target test process number threshold = 10).

[0181] Completed interval data: R1 interval: A total of 10 experiments were conducted. Cluster analysis revealed 6 matching experimental processes, with a matching experimental ratio of 6 / 10 = 0.6. Among the matching experimental processes in this interval, 5 processes showed high consistency with the typical curves of other completed intervals (R2, R3), with a reliable experimental process ratio of 5 / 6 ≈ 0.83, which is within the preset quantity ratio range [0.6, 1.0].

[0182] R2 interval: 5 matching test procedures, matching test ratio = 5 / 10 = 0.5. 4 confidence test procedures, confidence ratio = 4 / 5 = 0.8, which is within the preset quantity ratio range.

[0183] R3 interval: 4 matching test procedures, matching test ratio = 4 / 10 = 0.4. 2 reliable test procedures, reliable ratio = 2 / 4 = 0.5, which is not within the preset quantity ratio range.

[0184] Step S41: Determine the proportion of matching trials in each completed interval: Completed, as shown above: R1=0.6, R2=0.5, R3=0.4.

[0185] Step S42: Determine the credible experimental process and its proportion for each completion interval: Completed, as shown above: R1 credibility percentage 0.83%, R2 credibility percentage 0.8%, R3 credibility percentage 0.5%.

[0186] Step S43: Determine the test control methods for the incomplete intervals R4 and R5 based on the data from the completed intervals; The percentage of completed intervals = the number of completed intervals / the total number of filtered intervals = 3 / 5 = 0.6.

[0187] The preset completion rate threshold is 0.5. Since 0.6 ≥ 0.5, the system proceeds to a more refined judgment.

[0188] Determine if there is a completion interval where the proportion of matched trials exceeds a preset threshold (0.5): R1 (0.6) and R2 (0.5) satisfy the condition (here, "greater than" does not include "equal to", that is, the stable completion interval is when the proportion of matched trials is greater than 0.5). Therefore, there exists a stable completion interval R1.

[0189] Check whether the percentage of reliable test processes that have achieved stable completion within these intervals is within the preset percentage range [0.6, 1.0]: The confidence percentage of R1 is 0.83 ∈ [0.6,1.0]. Therefore, the confidence percentage of the stable completion interval is within the preset range, and we proceed to case 2.

[0190] The stable completion interval with a credible percentage within a preset range is defined as the credible completion interval: R1 is the credible completion interval.

[0191] The proportion of the credible completion interval to the stable completion interval is 1 / 3 = 0.33. The preset threshold for the proportion of the credible interval is 0.7. Therefore, the test control method for the incomplete rotation speed intervals (R4 and R5) is determined as follows: the test control method for the fully automatic soil shrinkage tester in the incomplete rotation speed interval is determined to stop the test only when the number of test processes reaches 20.

[0192] In other cases, when the basic number of 6 tests is reached, the test will be stopped as long as the percentage of the number of processes in the credible test process is not within the preset percentage range [0.6, 1.0].

[0193] Explanation: For R4 and R5, conduct the initial 6 trials. After completing 6 trials, calculate the percentage of reliable test processes for each (i.e., the proportion of processes that highly match the typical curves of existing completed intervals R1, R2, and R3 out of the matching test processes). If this percentage is below 0.6, it indicates poor consistency between this speed interval and the existing reliable benchmark, resulting in low reliability. The test should be stopped immediately to avoid wasting resources. If this percentage is 0.6 or above, it indicates high reliability for this interval. In this case, continue testing up to the preset threshold of 20 test processes to obtain more reliable data and provide a more sufficient reference for subsequently identifying the optimal rotational speed interval.

[0194] This embodiment utilizes high-quality data from existing completed intervals to develop a dynamic stopping strategy for incomplete intervals. When the proportion of reliable completed intervals is high, incomplete intervals only need to decide whether to continue based on their own reliability after a certain number of trials. This ensures sufficient data acquisition in reliable intervals (using a preset number of 20 trials) while promptly terminating trials in unreliable intervals, thereby improving the overall efficiency of identifying the optimal rotation speed interval. Simultaneously, by designing a threshold for the number of matching processes, it is possible to identify incomplete intervals with the potential to become stable completed intervals (such as R5) and allocate more trial resources to them, further optimizing resource allocation.

[0195] Example 2 Secondly, such as Figure 3 As shown, this invention provides a fully automatic soil shrinkage tester, employing the control method described above for the fully automatic soil shrinkage tester, specifically including: Mechanical frame, measurement system, control system, power supply system, and human-machine interaction system; The mechanical frame is a stable test frame made of aluminum alloy profiles, integrating a motor-driven platform to support the sample; the measurement system includes an electronic balance and a deformation measurement unit: the electronic balance is placed below the lifting platform, and the deformation measurement unit measures the soil sample deformation; the control system includes a core controller, a motor drive device, and a data acquisition device; the power supply system is used to supply power to the control system and the measurement system, and the human-machine interaction system uses a touch screen as the display and operation interface.

[0196] Specifically, initialization: Place the balance, install the sample holder and dial indicator, and raise the platform to the highest position (about 10mm above the balance). After zeroing the balance, lower the platform until the sample holder is completely pressed on the balance, record this weight as the "tare weight" and save it.

[0197] Start of Experiment: The platform automatically descends until the balance reading is >400g and the software displacement is <0.5mm, then stops. After 10 seconds, the initial weight of the soil sample is collected. The platform automatically rises until the displacement is >10mm and the balance reading is <100g, then stops. After 50 seconds, a stable initial reading from the dial gauge is collected. Entering the Cyclic Data Acquisition Phase: According to the set time intervals, the platform periodically descends to weigh and rises to measure displacement until the maximum number of data points is reached (e.g., 12 days of data). The platform is then driven by a motor to acquire soil sample deformation.

[0198] Data storage: After each complete acquisition cycle (one weighing + one displacement measurement), the system packages the time, weight, and displacement data into its internal non-volatile memory, which can store more than 1,000 records.

[0199] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of apparatus, devices, and non-volatile computer storage media are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0200] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0201] The above description is merely one or more embodiments of this specification and is not intended to limit this specification. Various modifications and variations can be made to the one or more embodiments of this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of one or more embodiments of this specification should be included within the scope of the claims of this specification.

Claims

1. A control method for a fully automatic soil shrinkage tester, characterized in that, Specifically, it includes: The volume change curve of soil with varying moisture content is determined using a soil shrinkage tester. The abnormal change periods in the historical measurement process are identified using the volume change curve. Based on the data of the abnormal change periods and the degree of overlap of the abnormal change periods, the adjustment strategy of the test rotation speed is determined. The adjustment strategy is used to adjust the test rotation speed. Based on the correlation between the volume change curve and other test rotation speed ranges, the selection rotation speed range in the test rotation speed range is determined. Using the test process data where the volume change curve in the selection rotation speed range meets the requirements, and combining the correlation between the test process where the volume change curve meets the requirements and the volume change curves in other test rotation speed ranges, the test control sequence of the selection rotation speed range is determined. According to the test control sequence, test control processing is carried out for different screening rotation speed ranges. Based on the consistency of the volume change curves in the screening rotation speed ranges and the existing completed screening rotation speed range data, the test control method of the fully automatic soil shrinkage tester in the screening rotation speed ranges that have not yet been tested is determined.

2. The control method for the fully automatic soil shrinkage tester as described in claim 1, characterized in that, The volume change curve of the soil as the moisture content changes is determined based on the scanning results of a laser or structured light scanner.

3. The control method for the fully automatic soil shrinkage tester as described in claim 1, characterized in that, The abnormal variation period in the historical measurement process is determined based on the degree of consistency between the measurement process and the volume variation curve in the most recent preset period in the same test area.

4. The control method for the fully automatic soil shrinkage tester as described in claim 1, characterized in that, The method for determining the adjustment strategy of the experimental rotation speed is as follows: Based on the data of the abnormal fluctuation period, the measurement process with the abnormal fluctuation period is identified and regarded as the abnormal measurement process; Based on the degree of overlap of the abnormal change periods of different abnormal measurement processes, the similarity coefficient of the abnormal change periods between different abnormal measurement processes is determined. By utilizing the abnormal measurement process data and the similarity coefficients of abnormal variation periods between different abnormal measurement processes, an adjustment strategy for the test rotation speed is determined.

5. The control method for the fully automatic soil shrinkage tester as described in claim 4, characterized in that, The similarity coefficient of the abnormal change periods between the abnormal measurement processes is determined by multiplying the number of overlapping abnormal change periods between the abnormal measurement processes with a preset scaling factor.

6. The control method for the fully automatic soil shrinkage tester as described in claim 4, characterized in that, Using the abnormal measurement process data and the similarity coefficients of abnormal variation periods between different abnormal measurement processes, an adjustment strategy for the test rotation speed is determined, specifically including: If the number of abnormal measurement processes is obtained and it is determined that the number of abnormal measurement processes is greater than a preset threshold for the number of measurement processes, then the adjustment strategy for the test rotation speed is determined to be based on a preset step size.

7. The control method for the fully automatic soil shrinkage tester as described in claim 1, characterized in that, The method for determining the test process in which the volume change curve meets the requirements is as follows: Based on the similarity coefficient of the volume change curves between different test processes within the aforementioned rotation speed range at different unit time intervals, test processes that meet the requirements for the similarity coefficient of their volume change curves at all unit time intervals are grouped into the same test process group. The test process in the group with the largest number of test processes is selected as the test process whose volume change curve meets the requirements.

8. The control method for the fully automatic soil shrinkage tester as described in claim 1, characterized in that, The method for determining the test control method of the fully automatic soil shrinkage tester within the untested screening rotation speed range is as follows: Based on the consistency of the volume change curves in the screening rotation speed range, the test process that falls into the test process group with the most test processes is determined. The updated data of the matching test process is determined using the test process that falls into the test process group with the most test processes. The updated data of the matching test process determines the proportion of the matching test process in the screening rotation speed range and is used as the matching test proportion. By utilizing the degree of consistency between the volume change curves of the screening rotation speed range and other screening rotation speed ranges that have been completed in the existing tests, it is determined that there are other screening rotation speed ranges in the screening rotation speed range that meet the consistency requirements, and these are taken as reliable test processes. Based on the existing experimental data, including the proportion of matching tests in different screening rotation speed ranges and reliable experimental process data, and combined with the existing experimental data on screening rotation speed ranges, the experimental control method of the fully automatic soil shrinkage tester in the screening rotation speed ranges that have not yet been tested is determined.

9. The control method for the fully automatic soil shrinkage tester as described in claim 8, characterized in that, The existing completed screening rotation speed range is taken as the completion range. If the proportion of the completion range within the screening rotation speed range is less than the preset completion proportion threshold, then the test control method of the fully automatic soil shrinkage tester in the screening rotation speed range that has not yet been tested is determined to be no test control, and the test will stop only when the number of test processes reaches the target number of test processes threshold.

10. A fully automatic soil shrinkage tester, employing the control method of the fully automatic soil shrinkage tester according to any one of claims 1-9, characterized in that, Specifically, it includes: Mechanical frame, measurement system, control system, power supply system, and human-machine interaction system; The mechanical frame is a stable test frame made of aluminum alloy profiles, integrating a motor-driven platform to support the test specimen; the measurement system includes an electronic balance and a deformation measurement unit: the electronic balance is placed below the lifting platform, and the deformation measurement unit measures the deformation of the soil sample; the control system includes a core controller, a motor drive device, and a data acquisition device. The power supply system is used to supply power to the control system and measurement system, while the human-machine interaction system uses a touch screen as the display and operation interface.

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