A method and system for excavating slope foundation trenches for prefabricated quick-assembly lattice beams.

Abstract

This invention relates to the field of earthwork trenching technology, specifically to a method and system for excavating slope trenches for prefabricated quick-assembly grid beams. In this invention, by collecting high-density discrete coordinates of the slope and constructing a reference straight-line vector connecting the beginning and end, the geometric correction depth of each surface point relative to the ideal flat bottom surface is calculated. This eliminates nonlinear errors caused by the original slope undulations, ensuring that the bottom surface of the trench accurately adapts to the straight-line configuration of the prefabricated components. The resistance gradient change characteristics during the excavation process are combined with a clustering algorithm to dynamically lock the interface between soft and hard geological layers. The excavation depth required by the geometric design is fused and compared with the measured depth of the geotechnical boundary in the same coordinate system. Based on the comparison results, differentiated cutting or stripping commands are intelligently generated. When encountering hard rock layers higher than the designed bottom surface, a fuzzy PID algorithm is activated to enhance hydraulic driving force and ensure cutting efficiency. In soft soil operating areas, standard pressure is maintained to reduce energy consumption.

Description

Technical Field

[0001] This invention relates to the field of earthwork trenching technology, and in particular to a method and system for excavating slope foundation trenches for prefabricated quick-assembly grid beams. Background Technology

[0002] The field of earthwork trenching construction technology involves construction methods for forming regular trenches for foundation structures or slope protection structures in engineering construction. This includes trench location layout, layered excavation, trench shape control, slope stabilization treatment, and trenching accuracy control adapted to subsequent structural installation. It is widely used in engineering scenarios such as slope reinforcement, retaining structure foundation treatment, etc.

[0003] Among them, the slope trench excavation method for precast quick-assembly lattice beams refers to the trench excavation operation carried out in slope treatment projects for the installation of precast lattice beams. Usually, according to the design drawings, the slope is measured and marked out. The excavator is used to excavate the beam rib trench from top to bottom or in sections and layers along the slope. The bottom and sidewalls of the trench are trimmed by manual labor so that the width, depth and direction of the trench meet the placement requirements of the precast beam. During the excavation process, the local stability of the slope is maintained by temporary support or segmented construction methods to complete the trench shape corresponding to the structural dimensions of the precast lattice beam.

[0004] Existing technologies largely rely on manual surveying and layout based on the slope undulations to guide excavation operations. Since natural slope surfaces often have non-linear unevenness, simply excavating along the slope direction will result in the bottom of the trench retaining the original topographical undulations, making it impossible to form a strictly straight plane to accommodate the flat installation bottom of rigid precast components. This leads to irregular gaps or localized stress concentrations between the components and the trench bottom after installation, severely affecting the stress stability of the support structure. Furthermore, without real-time perception of the depth of the underground soil-rock boundary, excavation operations cannot be adaptively adjusted according to sudden changes in geological hardness. Blindly operating can easily cause equipment overload damage due to encountering hidden hard rock, or cause unnecessary energy consumption and over-excavation damage to the trench due to excessive pressure in soft soil areas. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and to propose a method and system for excavating slope trenches for prefabricated quick-assembly lattice beams.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for excavating slope foundation trenches for prefabricated quick-assembly lattice beams, comprising the following steps:

[0007] S1: Obtain the sequence of discrete coordinate points on the slope surface and the standard length of the precast lattice beam. Calculate the Euclidean distance between corresponding adjacent coordinate points and accumulate it to obtain the arc length of the geodesic line on the slope surface. Construct a design straight line reference vector connecting the first and last coordinate points based on the difference between the design straight line reference vector and the standard length of the precast lattice beam. Calculate the vertical distance from each discrete coordinate point to the design straight line reference vector to obtain the geometric correction depth parameter.

[0008] S2: During the excavation process, the bucket pressure data is collected and mapped to the soil penetration resistance value. The resistance gradient value is calculated by difference. Based on the change of the resistance gradient value, the locking depth of the geological interface is determined.

[0009] S3: Calculate the elevation of the bottom surface of the geometric target based on the current excavation location and the geometric correction depth parameter, and combine it with the geological interface locking depth to calculate the measured elevation of the soil-rock boundary, forming an excavation decision elevation pair;

[0010] S4: Compare the numerical values ​​of the excavation decision elevation pairs, generate cutting control commands or overburden stripping control commands, and integrate them into an adaptive excavation control command set;

[0011] S5: Analyze the set of adaptive excavation control instructions, and drive the bucket to perform crushing excavation or soil removal actions by adjusting the hydraulic pressure to form a straight grid beam foundation trench.

[0012] As a further aspect of the present invention, the geometric correction depth parameter is specifically a value obtained by calculating the vertical distance from each discrete coordinate point to the design straight line reference vector; the geological interface locking depth is specifically a value obtained by the depth position coordinates when the locking resistance gradient value first exceeds the hard soil layer determination threshold; the excavation decision elevation pair includes the geometric target bottom elevation and the measured elevation of the soil-rock boundary; the adaptive excavation control command set includes cutting control commands and overburden stripping control commands; and the straight-line lattice beam foundation trench is specifically a straight-line foundation trench located at the geometric target bottom elevation.

[0013] As a further aspect of the present invention, the step of obtaining the geometric correction depth parameter specifically includes:

[0014] S111: Obtain the sequence of discrete coordinate points on the slope surface distributed along the design direction, as well as the standard length of the precast lattice beam. Calculate the Euclidean distance between adjacent coordinate points in the sequence of discrete coordinate points on the slope surface. Accumulate multiple Euclidean distances and statistically obtain the arc length of the geodesic line on the slope surface corresponding to the slope surface.

[0015] S112: Compare the arc length of the geodesic line on the slope surface with the standard length of the precast lattice beam. When the arc length of the geodesic line on the slope surface exceeds the standard length of the precast lattice beam, extract the first and last discrete coordinate points of the slope surface in the discrete coordinate point sequence and construct a design straight line reference vector connecting the first and last coordinate points.

[0016] S113: Calculate the vertical distance of each discrete coordinate point in the sequence of discrete coordinate points on the slope surface relative to the design straight line reference vector, and mark the vertical distance as the geometric correction depth parameter corresponding to the discrete coordinate point.

[0017] As a further aspect of the present invention, the step of obtaining the geological interface locking depth specifically comprises:

[0018] S211: Collect the feedback data from the bucket tooth pressure sensor when the excavator performs the downward digging action and map it into the soil penetration resistance value. Simultaneously collect the digging depth coordinates at the current moment, calculate the difference in soil penetration resistance value and the difference in digging depth coordinates between adjacent collection moments, and calculate the resistance gradient value based on the difference in soil penetration resistance value and the difference in digging depth coordinates.

[0019] S212: The resistance gradient values ​​are used to form a resistance gradient value sequence and input into the Fisher ordered clustering algorithm to perform operations on the ordered sample sequence, calculate the optimal split point position of the resistance gradient value sequence, and extract the best hardness determination threshold to distinguish geological hardness characteristics based on the optimal split point position.

[0020] S213: Compare the resistance gradient value collected and calculated in real time with the optimal hardness determination threshold, locate the excavation depth coordinates when the resistance gradient value first exceeds the optimal hardness determination threshold, and obtain the geological interface locking depth.

[0021] As a further aspect of the present invention, the step of obtaining the mining decision elevation pair specifically includes:

[0022] S311: Obtain the horizontal coordinates of the current excavation location and match the corresponding discrete coordinates of the slope surface from the sequence of discrete coordinates of the slope surface, extract the corresponding elevation data, call the geometric correction depth parameter corresponding to the current excavation location, calculate the difference between the elevation data of the discrete coordinates of the slope surface and the geometric correction depth parameter, and obtain the elevation of the bottom surface of the geometric target.

[0023] S312: Call the elevation data of the discrete coordinate points on the slope surface corresponding to the current excavation location, and combine it with the geological interface locking depth to calculate the difference between the elevation data of the discrete coordinate points on the slope surface and the geological interface locking depth, so as to obtain the measured elevation of the soil-rock boundary.

[0024] S313: Combine the bottom elevation of the geometric target at the same excavation location with the measured elevation of the soil-rock boundary to establish an excavation decision elevation pair.

[0025] As a further aspect of the present invention, the step of obtaining the adaptive mining control command set specifically includes:

[0026] S411: Analyze the values ​​of the measured elevation of the soil-rock boundary and the elevation of the bottom surface of the geometric target from the excavation decision elevation pair, determine whether the measured elevation of the soil-rock boundary is greater than the elevation of the bottom surface of the geometric target, and generate a criterion for the relative relationship of elevation values.

[0027] S412: Based on the relative elevation values, when the measured elevation of the soil-rock boundary is greater than the elevation of the bottom surface of the geometric target, a cutting control command is generated; when the measured elevation of the soil-rock boundary is less than or equal to the elevation of the bottom surface of the geometric target, a soil stripping control command is generated, thus obtaining a single-excavation mode execution command.

[0028] S413: Encapsulate the cutting control command or overburden stripping control command in the single excavation mode execution command into a standardized control signal format and output it as an adaptive excavation control command set.

[0029] As a further aspect of the present invention, the specific steps for obtaining the linear lattice beam foundation trench are as follows:

[0030] S511: If the adaptive excavation control command set includes a cutting control command, then activate the fuzzy PID control algorithm logic to determine to increase the hydraulic pressure; if the adaptive excavation control command set includes a cover soil stripping control command, then maintain the standard hydraulic pressure and determine the hydraulic equipment pressure regulation strategy.

[0031] S512: Execute the hydraulic equipment pressure regulation strategy, calculate the required increase in hydraulic pressure using a fuzzy PID control algorithm, or directly lock the standard hydraulic pressure, adjust the output power of the excavator's hydraulic equipment, and generate bucket drive hydraulic pressure;

[0032] S513: The excavator bucket is driven by hydraulic pressure to operate on the soil, continuously removing soil until the bottom elevation of the geometric target is reached and the excavation action is stopped, thus constructing a straight lattice beam foundation trench on the slope surface.

[0033] A slope trench excavation system for prefabricated quick-assembly lattice beams, the system comprising:

[0034] The geometric correction module obtains the sequence of discrete coordinate points on the slope surface and the standard length of the precast lattice beam. It calculates the Euclidean distance between corresponding adjacent coordinate points and accumulates it to obtain the arc length of the geodesic line on the slope surface. The difference between the arc length and the standard length of the precast lattice beam is used to construct a design straight line reference vector connecting the first and last coordinate points. The vertical distance from each discrete coordinate point to the design straight line reference vector is calculated to obtain the geometric correction depth parameter.

[0035] The interface recognition module collects bucket pressure data during the excavation process, maps it to soil penetration resistance values, calculates the difference to obtain resistance gradient values, and determines the geological interface locking depth based on the changes in resistance gradient values.

[0036] The elevation calculation module calculates the elevation of the bottom surface of the geometric target based on the elevation of the current excavation location and the geometric correction depth parameters, and calculates the measured elevation of the soil-rock boundary in combination with the geological interface locking depth to form an excavation decision elevation pair.

[0037] The control and determination module compares the numerical values ​​of the excavation decision elevation pairs, generates cutting control commands or overburden stripping control commands, and integrates them into an adaptive excavation control command set.

[0038] The trenching module is executed to parse the set of adaptive excavation control commands and drive the bucket to perform crushing excavation or soil removal actions by adjusting the hydraulic pressure, thereby forming a straight grid beam trench.

[0039] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0040] In this invention, by collecting high-density discrete coordinates of the slope and constructing a reference straight line vector connecting the beginning and end, the geometric correction depth of each surface point relative to the ideal flat bottom surface is calculated. This eliminates the nonlinear error caused by the original slope undulation, ensuring that the bottom surface of the trench accurately adapts to the straight configuration of the precast components. By utilizing the resistance gradient change characteristics during the excavation process combined with a clustering algorithm, the interface between soft and hard geological surfaces is dynamically locked. The excavation depth required by the geometric design and the measured depth of the rock and soil physical boundary are fused and compared in the same coordinate system. Based on the comparison results, differentiated cutting or stripping commands are intelligently generated. When encountering hard rock layers that are higher than the design bottom surface, the fuzzy PID algorithm is activated to enhance the hydraulic driving force and ensure cutting efficiency. In the soft soil operation area, the standard pressure is maintained to reduce energy consumption, realizing full adaptive control of trench excavation from geometric shape correction to dynamic parameter matching. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the workflow of the present invention;

[0042] Figure 2 This is a flowchart of the geometric correction depth parameter acquisition process of the present invention;

[0043] Figure 3This is a flowchart of the geological interface locking depth locking process of the present invention;

[0044] Figure 4 To establish a flowchart for the decision elevation pair in this invention;

[0045] Figure 5 This is a flowchart illustrating the generation process of the adaptive mining control instruction set of the present invention.

[0046] Figure 6 This is a flowchart illustrating the excavation process for the linear lattice beam foundation trench of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] Please see Figure 1 This invention provides a technical solution: a method for excavating slope foundation trenches for prefabricated quick-assembly lattice beams, comprising the following steps:

[0049] S1: Obtain the sequence of discrete coordinate points on the slope surface and the standard length of the precast lattice beam. Calculate the Euclidean distance between corresponding adjacent coordinate points and accumulate it to obtain the arc length of the geodesic line on the slope surface. Construct a design straight line reference vector connecting the first and last coordinate points based on the difference between the design straight line reference vector and the standard length of the precast lattice beam. Calculate the vertical distance from each discrete coordinate point to the design straight line reference vector to obtain the geometric correction depth parameter.

[0050] S2: During the excavation process, the bucket pressure data is collected and mapped to the soil penetration resistance value. The resistance gradient value is calculated by difference. Based on the change of the resistance gradient value, the locking depth of the geological interface is determined.

[0051] S3: Calculate the elevation of the bottom surface of the geometric target based on the current excavation location and the geometric correction depth parameters, and combine the geological interface locking depth to calculate the measured elevation of the soil-rock boundary to form an excavation decision elevation pair;

[0052] S4: Compare the numerical values ​​of the excavation decision elevation pairs, generate cutting control commands or overburden stripping control commands, and integrate them into an adaptive excavation control command set.

[0053] S5: Analyzes the set of adaptive excavation control instructions, and drives the bucket to perform crushing excavation or soil removal actions by adjusting the hydraulic pressure to form a straight grid beam foundation trench.

[0054] The geometric correction depth parameter is specifically obtained by calculating the vertical distance from each discrete coordinate point to the design straight line reference vector. The geological interface locking depth is specifically obtained by the depth position coordinates when the locking resistance gradient value first exceeds the hard soil layer judgment threshold. The excavation decision elevation pair includes the geometric target bottom elevation and the measured elevation of the soil-rock boundary. The adaptive excavation control command set includes cutting control commands and overburden stripping control commands. The straight lattice beam foundation trench is specifically a straight foundation trench located at the geometric target bottom elevation.

[0055] Please see Figure 2 The specific steps for obtaining the geometric correction depth parameters are as follows:

[0056] S111: Obtain the sequence of discrete coordinate points on the slope surface distributed along the design direction, as well as the standard length of the precast lattice beam. Calculate the Euclidean distance between adjacent coordinate points in the sequence of discrete coordinate points on the slope surface. Accumulate multiple Euclidean distances and statistically obtain the arc length of the geodesic line on the slope surface corresponding to the slope surface.

[0057] A high-precision airborne LiDAR scanner was used to perform a full-coverage scan of the target slope area, acquiring raw point cloud data containing a large amount of three-dimensional spatial information. The raw point cloud data was preprocessed to remove noise caused by vegetation obstruction or airborne dust. A statistical outlier removal algorithm was used to calculate the average distance from each point in the point cloud to its 50 nearest neighbors. The mean and standard deviation of this set of average distances were calculated, and points with an average distance greater than "mean plus 1.0 standard deviation" were marked as outliers and removed, thus obtaining a clean sequence of discrete coordinate points on the slope surface. The standard length of the precast lattice beams was set as a fixed parameter. The Euclidean distance between adjacent coordinate points was calculated. The three-dimensional coordinate values ​​of the currently traversed starting coordinate point and the next adjacent coordinate point in the sequence were extracted. The differences between the two coordinate points in the horizontal, vertical, and elevation directions were calculated respectively. Then, the differences in these three directions were squared, and the three squared values ​​were summed to obtain a total sum of squares. Finally, the arithmetic square root of the total sum of squares was performed to obtain the linear spatial distance between the two points. Following this logic, the program automatically traverses the entire sequence, calculating the Euclidean distance between each pair of adjacent points. It then sums all the calculated independent Euclidean distances, adding the first distance to the second, and then adding the result to each subsequent distance until all adjacent point distances are included in the calculation. The final sum represents the geodesic arc length of the slope surface. For example, in the actual processing flow, the program starts from the first point at the bottom of the slope and traces each discrete point towards the top, accumulating the lengths of all the tiny straight line segments along the way to obtain a total unfolded length that reflects the true undulation of the slope surface.

[0058] S112: Compare the arc length of the geodesic line on the slope surface with the standard length of the precast lattice beam. When the arc length of the geodesic line on the slope surface exceeds the standard length of the precast lattice beam, extract the first and last discrete coordinate points of the slope surface in the discrete coordinate point sequence and construct a design straight line reference vector connecting the first and last coordinate points.

[0059] The program determines whether the arc length of the geodesic line on the slope surface exceeds the standard length of the precast lattice beam. If the result is yes, meaning the actual unfolded length of the slope surface exceeds the precast specifications of the lattice beam, then a straightening correction is required to adapt to the precast component. The program accesses the stored sequence of discrete coordinate points on the slope surface, locates and extracts the first coordinate point with an index value of 1 and the last coordinate point with an index value of the total sequence length n. Using the first coordinate point as the starting endpoint of the vector and the last coordinate point as the ending endpoint, a spatial straight line vector running through the beginning and end of the slope is constructed. This vector is defined as the design straight line reference vector. For example, when the comparison logic finds that the calculated actual arc length of the slope exceeds the preset standard length of the component, the program automatically ignores the intermediate undulations and directly extracts the first and last coordinate points of the sequence, establishing a spatial straight line equation connecting these two points. This straight line serves as the benchmark for subsequent calculations of the excavation depth, representing, ideally, a flat installation bottom surface that should be formed during excavation to adapt to the straight lattice beam.

[0060] S113: Calculate the vertical distance of each discrete coordinate point in the sequence of discrete coordinate points on the slope surface relative to the design straight line reference vector, and mark the vertical distance as the geometric correction depth parameter corresponding to the discrete coordinate point;

[0061] For any discrete target coordinate point in the sequence, its three-dimensional spatial coordinates are obtained, and the spatial straight line equation parameters of the design straight line reference vector are called. Applying the point-to-line distance calculation logic, a spatial triangle is constructed consisting of the discrete target coordinate point and the start and end points of the design straight line reference vector. The area of ​​this triangle is calculated using Heron's formula or the modulus of the cross product of vectors. Using the length of the design straight line reference vector as the base length, the triangle area is multiplied by 2 and then divided by the base length; the quotient is the vertical distance of the discrete coordinate point relative to the design straight line reference vector. This vertical distance physically characterizes the degree of convexity or concavity of a point on the slope surface relative to the ideal design plane. This vertical distance value is directly assigned and marked as the geometric correction depth parameter corresponding to the discrete coordinate point, and the parameters of all points are stored sequentially. For example, when processing each surface point, the program calculates the shortest geometric distance from that point to the ideal design straight line. If the point is spatially higher than the design straight line, the calculated non-zero vertical distance represents the specific depth correction amount that the excavator needs to dig downwards and remove soil to achieve the required flat bottom surface at that location.

[0062] Please see Figure 3 The specific steps for obtaining the depth of the geological interface are as follows:

[0063] S211: Collect the feedback data from the bucket tooth pressure sensor when the excavator performs the downward digging action and map it into the soil penetration resistance value. Simultaneously collect the digging depth coordinates at the current moment, calculate the difference in soil penetration resistance value and the difference in digging depth coordinates between adjacent collection moments, and calculate the resistance gradient value based on the difference in soil penetration resistance value and the difference in digging depth coordinates.

[0064] The process of mapping to soil penetration resistance values ​​is as follows:

[0065] Obtain the pre-calibrated piston action area and the soil contact cross-sectional area of ​​the bucket teeth;

[0066] The downward driving force transmitted to the end of the bucket is calculated based on the feedback data from the pressure sensor of the hydraulic cylinder of the excavator boom or stick and the piston action area.

[0067] Calculate the soil penetration resistance value based on the value of the downward driving force and the cross-sectional area of ​​the soil contact.

[0068] Activate the thin-film pressure sensor installed at the root of the excavator bucket teeth, setting the sampling frequency to 100 Hz. Acquire the real-time electrical signal feedback from the pressure sensor and convert it into a pressure value in megapascals (MPa). Retrieve the cross-sectional area parameters of the hydraulic cylinder piston and the cross-sectional area parameters of the bucket teeth in contact with the soil. Calculate the downward driving force by multiplying the pressure value fed back by the sensor by the piston cross-sectional area value to obtain the downward driving force value transmitted to the end of the bucket. Divide the downward driving force value by the cross-sectional area value of the bucket teeth in contact with the soil; the quotient is the current soil penetration resistance value. Simultaneously record the current data from the excavator boom, arm, and bucket angle sensors, and obtain the digging depth coordinates of the bucket tip through forward kinematics calculation. In the time series, extract the data from the current time t and the previous sampling time t minus 1, calculate the difference between the current soil penetration resistance value and the previous soil penetration resistance value to obtain the resistance change; calculate the difference between the current digging depth coordinates and the previous digging depth coordinates to obtain the depth change. The ratio of the change in resistance to the change in depth is the resistance gradient value. For example, during excavation, as the bucket cuts downwards, the pressure value recorded by the sensor is converted into unit pressure acting on the bucket teeth. By monitoring the incremental change of this pressure within a unit depth change, the program can quantify the severity of the change in current geological hardness in real time, thereby determining whether hard rock layers have been encountered.

[0069] S212: The resistance gradient values ​​are combined into a resistance gradient value sequence and input into the Fisher ordered clustering algorithm to perform operations on the ordered sample sequence, calculate the optimal split point position of the resistance gradient value sequence, and extract the best hardness determination threshold to distinguish geological hardness characteristics based on the optimal split point position.

[0070] Construct a length of An ordered sample sequence of resistance gradient values, wherein The sampling points are set to 200 consecutive points, a value determined based on the sampling density requirements of a single excavator operation. This sequence is then input into the Fisher ordered clustering algorithm for processing the ordered sample sequence. The core of the algorithm lies in determining the optimal split point by minimizing the intra-cluster scatter. An arbitrary subset of the sample sequence (from the index...) is defined... arrive ) class diameter The diameter characterizes the degree of dispersion of the data within this subset, and is calculated using the following formula: In the formula, The first sample in the ordered sequence representing the resistance gradient value The resistance gradient value at each location is derived from the real-time calculation and storage of the preceding steps; Represents from index arrive This is the arithmetic mean of all resistance gradient values ​​in this sample subset, used to reflect the central tendency of the subset; subscript and The starting and ending indices of the subset are used to determine the calculation window range; squaring operation. Used to eliminate positive and negative biases and amplify the effects of larger errors. Performs a full sequence scan to find the optimal segmentation point. The goal is to minimize the sum of the class diameters of the two segmented subsequences, i.e., to calculate the total loss function. : In the formula, The index of the candidate split point, with a value range of 1. ; The diameter of the class representing the soft soil layer sample set to the left of the dividing point; Let the diameter of the class representing the hard soil layer sample set be the one to the right of the split point. Iterate through all possible... Value, select order When the minimum value is obtained This serves as the optimal segmentation point. Based on this optimal segmentation point, the subsequent hard soil layer sample set (index) is extracted. to The mean of the values, multiplied by the hardness reduction factor. (This coefficient is set based on the confidence level of historical mining data, with a value range of 0.6 to 0.9. The greater the data fluctuation, the smaller the coefficient value; here, 0.8 is used.) This yields the optimal hardness determination threshold. .

[0071] Suppose a simplified sequence is collected. ,length Try in the index. Partition (i.e., between 12 and 80): Left subset mean The diameter of the class is (10+12) / 2, which equals 11. right subset mean The diameter of the class is (80+82) / 2, which equals 81. Total loss If you try in The dividing line (between 10 and 12): left side The single-point variance is 0, that is Right side The mean (12+80+82) / 3 equals 58. Total loss It is obvious Therefore, the optimal split point is Threshold calculation: The average value for hard soil layers is 81. ,but Megapascals per meter. This calculation process ensures that the threshold can adaptively distinguish between soft and hard abrupt changes in the current geological environment.

[0072] S213: Compare the resistance gradient value collected and calculated in real time with the optimal hardness judgment threshold, locate the excavation depth coordinates when the resistance gradient value first exceeds the optimal hardness judgment threshold, and obtain the geological interface locking depth.

[0073] The program continuously reads the real-time calculated resistance gradient value and compares it with the optimal hardness threshold determined in the previous steps. A judgment logic is set up: when the real-time resistance gradient value is greater than the optimal hardness threshold for three consecutive samples, it is determined to be a valid crossing of the geological interface. Once this condition is met, the program immediately locks the excavation depth coordinates corresponding to the moment the threshold is first exceeded. The elevation component in this coordinate system is marked as the geological interface locking depth, representing the physical boundary between the overlying soil layer and the underlying bedrock or hard soil layer. For example, during continuous excavation monitoring, the program continuously compares the resistance gradient values ​​at the current moment and the past two moments with the calculated threshold. If a step increase is detected, and the value after the increase stably exceeds the hardness threshold three times consecutively, the program confirms the current depth as a geological abrupt change point and records the depth value at this point as the boundary distinguishing the upper soft soil layer from the lower hard rock layer.

[0074] Please see Figure 4 The specific steps for obtaining decision elevation pairs are as follows:

[0075] S311: Obtain the horizontal coordinates of the current excavation location and match the corresponding discrete coordinates of the slope surface from the sequence of discrete coordinates of the slope surface, extract the corresponding elevation data, call the geometric correction depth parameter corresponding to the current excavation location, calculate the difference between the elevation data of the discrete coordinates of the slope surface and the geometric correction depth parameter, and obtain the elevation of the bottom surface of the geometric target.

[0076] The horizontal coordinates of the excavator bucket's current position, including east (E) and north (N), are obtained in real time via the Global Navigation Satellite System. Using these horizontal coordinates, a nearest neighbor search is performed on a pre-stored sequence of discrete coordinate points on the slope surface. The planar distance between the current horizontal coordinates and the horizontal coordinates of each point in the sequence is calculated, and the point with the smallest planar distance is selected as the matching discrete coordinate point on the slope surface. The original surface elevation data of this point is then extracted. The geometric correction depth parameter corresponding to this matching point is retrieved from memory. A subtraction operation is performed, subtracting the geometric correction depth parameter from the original surface elevation data of the discrete coordinate point on the slope surface. The difference obtained is the geometric target bottom elevation. This elevation represents, in design theory, the excavator should reach the excavation endpoint elevation to form a straight bottom surface of the lattice beam foundation trench. For example, based on the current horizontal position, the program finds the corresponding original surface elevation and pre-calculated correction depth in the database. By performing a subtraction operation, the absolute elevation that the bottom of the foundation trench should reach geometrically to meet the straight installation requirements of the lattice beam, regardless of changes in geological conditions.

[0077] S312: Call the elevation data of the discrete coordinate points on the slope surface corresponding to the current excavation location, combine it with the geological interface locking depth, calculate the difference between the elevation data of the discrete coordinate points on the slope surface and the geological interface locking depth, and obtain the measured elevation of the soil-rock boundary.

[0078] The program retrieves the original elevation data of the discrete coordinate points on the slope surface matched at the current excavation location, and reads the geological interface locking depth value. This geological interface locking depth is typically defined as the depth of excavation from the surface downwards. A subtraction operation is performed, subtracting the geological interface locking depth from the original elevation data of the discrete coordinate points on the slope surface. The difference is the measured elevation of the soil-rock boundary. This elevation value marks the specific location where the soft soil layer ends and the hard rock layer begins in the absolute elevation coordinate system. For example, by subtracting the depth of the rock layer measured and locked by the sensor from the original surface elevation of the current location, the program can calculate the elevation of the top surface of the rock layer in the absolute coordinate system, thus clearly defining the spatial boundary plane between the soft soil layer and the hard rock layer.

[0079] S313: Collect the geometric target bottom elevation and the measured elevation of the soil-rock boundary at the same excavation location to establish an excavation decision elevation pair;

[0080] The geometric target bottom elevation calculated from the same excavation horizontal location is linked and bound to the measured elevation of the soil-rock boundary. A data pair format containing two floating-point data fields is defined: field one is named "Design Bottom" and field two is named "Soil-Rock Interface". The geometric target bottom elevation calculated in the previous steps is written into field one, and the measured elevation of the soil-rock boundary is written into field two, thus constructing a specific excavation decision elevation pair. This data pair is immediately pushed to the decision logic module for subsequent judgment of the nature of the excavation action. This step realizes the digital aggregation of geometric design constraints and geophysical constraints in the same coordinate dimension.

[0081] Please see Figure 5 The specific steps for obtaining the adaptive mining control command set are as follows:

[0082] S411: Analyze the values ​​of the measured elevation of the soil-rock boundary and the bottom elevation of the geometric target from the excavation decision elevation pair, determine whether the measured elevation of the soil-rock boundary is greater than the bottom elevation of the geometric target, and generate a criterion for the relative relationship of elevation values.

[0083] The program reads two core values ​​from the excavation decision elevation pair. It then executes a numerical comparison logic to determine if the measured elevation of the soil-rock boundary is strictly greater than the elevation of the geometric target bottom surface. This determination physically confirms whether the hard rock layer is higher than the designed trench bottom plane. If the comparison result is true (meaning the measured elevation of the soil-rock boundary is greater than the geometric target bottom surface elevation), a Boolean flag of "true" is generated, indicating that rock will be encountered before reaching the designed trench bottom. If the comparison result is false (meaning the measured elevation of the soil-rock boundary is less than or equal to the geometric target bottom surface elevation), a Boolean flag of "false" is generated, indicating that the entire trench before reaching the designed bottom will be soft soil or the area will just reach the rock surface. For example, by comparing the calculated absolute height of the rock surface with the absolute height of the designed bottom surface, if the rock surface is higher, the location is marked as requiring rock cutting; if the rock surface is lower or the two are equal, the location is marked as requiring only earthwork excavation.

[0084] S412: Based on the relative relationship criterion of elevation values, when the measured elevation of the soil-rock boundary is greater than the elevation of the bottom surface of the geometric target, a cutting control command is generated; when the measured elevation of the soil-rock boundary is less than or equal to the elevation of the bottom surface of the geometric target, a soil stripping control command is generated, thus obtaining the single excavation mode execution command.

[0085] When the criterion indicates that the measured elevation of the soil-rock boundary is greater than the elevation of the geometric target bottom surface (i.e., the flag is "true"), it means that the designed trench bottom is located inside the rock layer, and it is necessary to cut into the rock to complete the trench construction. Based on this, a "cutting control command" is generated, and the corresponding operation code is set to a specific value. When the criterion indicates that the measured elevation of the soil-rock boundary is less than or equal to the elevation of the geometric target bottom surface (i.e., the flag is "false"), it means that the designed trench bottom is located within the soft soil layer or just on the interface, and it is not necessary to cut into the rock; only the surface soil needs to be removed. Based on this, a "cover soil stripping control command" is generated, and the corresponding operation code is set to another specific value. For example, based on the Boolean judgment result of the previous step, if the logical flag confirms that it is necessary to cut into the rock layer, the program will automatically generate and issue a high-load mode control command; if it confirms that the operation is only within the soil layer, it will generate and issue a conventional excavation mode command.

[0086] S413: Encapsulates the cutting control command or overburden stripping control command in the single excavation mode execution command into a standardized control signal format and outputs it as an adaptive excavation control command set.

[0087] The generated single-item excavation mode execution instructions are encapsulated. A data frame containing a frame header, instruction type code, and checksum is constructed. Cutting control instructions or overburden stripping control instructions are filled into the instruction payload segment of the data frame. If the current excavation task involves multiple consecutive excavation points, the multiple data frames generated sequentially are packaged to form an instruction queue. This queue is the adaptive excavation control instruction set. For example, for a continuously extending trench, the program will generate a series of excavation instructions corresponding to each location based on geological criteria along the line, and package these instructions to send to the excavator's main control unit, enabling it to automatically switch the corresponding excavation strategy according to the actual geological conditions at each meter during the excavation process.

[0088] Please see Figure 6 The specific steps for obtaining the foundation trench of the straight lattice beam are as follows:

[0089] S511: If the adaptive excavation control command set includes a cutting control command, then activate the fuzzy PID control algorithm logic to determine to increase the hydraulic pressure; if the adaptive excavation control command set includes a cover soil stripping control command, then maintain the standard hydraulic pressure and determine the hydraulic equipment pressure regulation strategy.

[0090] The system parses the currently executing command from the received adaptive excavation control command set. If the parsed command is a cutting control command, the current working condition is identified as high-load rock cutting. The fuzzy PID control algorithm logic module is then activated, and the target pressure setpoint is adjusted to the high-pressure cutting mode standard. In this case, the strategy is marked as "dynamic pressure boosting." If the parsed command is a cover soil stripping control command, the current working condition is identified as low-load earthmoving. The fuzzy PID control module is directly bypassed or its parameters are frozen to maintain the hydraulic system at standard excavation pressure. In this case, the strategy is marked as "standard constant pressure maintenance." This step, by predicting working condition requirements, achieves optimized energy and efficiency configuration, avoiding energy waste caused by blindly increasing pressure during soft soil operations or excavation jamming due to insufficient pressure during rock operations.

[0091] S512: Executes hydraulic equipment pressure regulation strategy, calculates the required increase in hydraulic pressure through fuzzy PID control algorithm, or directly locks the standard hydraulic pressure, adjusts the output power of the excavator's hydraulic equipment, and generates bucket drive hydraulic pressure;

[0092] Based on the real-time pressure error and error change rate, key parameters in the PID controller are adjusted in real time. Here, we take adjusting the proportional gain coefficient as an example. The adaptive proportional gain coefficient at the current moment is calculated. The calculation formula is expressed as follows: In the formula, This is the preset initial static proportional gain used to ensure the basic response capability of the system. This value is tuned using the Ziegler-Nichols method based on the open-loop step response test data of the hydraulic system, for example, set to 4.5. This is the gain adjustment quantization factor, used to control the impact of fuzz correction on the overall parameters. The value range is usually between 0.05 and 0.2. The higher the value is set, the more drastic the parameter adjustment will be. Here it is set to 0.1. This represents the total number of fuzzy rules activated at the current sampling time. Representing the The activation intensity of the activated rule is calculated from the minimum value of the membership function of the antecedent part of the rule, namely the pressure error and the rate of change of error, and reflects the degree of matching between the current working condition and the rule description. Representing the The single-point fuzzy output value corresponding to the consequent of the rule is the gain correction value suggested by the expert experience base.

[0093] Set base gain Quantification factor Assume the current operating condition activates two rules: Rule 1 (high operating condition matching degree), triggering intensity... Corresponding suggested correction value Rule 2 (low working condition matching degree), excitation intensity Corresponding suggested correction value Substitute into the formula to calculate the weighted correction term: numerator part ; denominator The weighted average is 2.6 / 1.0, which equals 2.6. The final real-time gain is calculated as follows: Subsequently, the full PID output calculation is performed using this real-time gain coefficient: First, the pressure error at the current moment is determined. The target cutting pressure is set to 35 MPa, and the sensor-measured pressure is 33 MPa. Subtracting the two yields an error value of 2 MPa. Multiplying the real-time gain coefficient of 4.76 calculated in the previous step by this error value of 2 MPa yields a proportional response value of 9.52. Simultaneously, the cumulative sum of historical errors within the past time window (assuming a cumulative value of 5) is calculated and multiplied by a preset integral coefficient of 0.1 to obtain an integral response value of 0.5. The rate of change of the current error relative to the previous moment (assuming a rate of change of 0.5) is calculated and multiplied by a preset derivative coefficient of 0.2 to obtain a derivative response value of 0.1. Finally, a summation operation is performed, adding the proportional response value of 9.52, the integral response value of 0.5, and the derivative response value of 0.1 to obtain a total control output of 10.12. The total control output obtained from the calculation is directly identified as the hydraulic pressure amplitude that needs to be increased. Based on this value, the system performs corresponding incremental adjustment operations on the hydraulic pump or control valve, thereby adjusting the output power of the excavator's hydraulic equipment, and finally generating a bucket drive hydraulic pressure at the end of the actuator that is sufficient to overcome the resistance of the current high-hardness rock.

[0094] S513: The excavator bucket is driven by hydraulic pressure to work on the soil, continuously removing soil until the bottom elevation of the geometric target is reached and the excavation action stops, and a straight grid beam foundation trench is constructed on the slope surface.

[0095] The excavator drives the bucket into the geological body, and during excavation, the elevation coordinates of the bucket teeth are fed back in real time at a frequency of 10 Hz. These real-time elevation coordinates are then compared with the geometric target bottom elevation. When the real-time elevation coordinates are greater than the geometric target bottom elevation, hydraulic pressure is maintained to continue the excavation downward pressing and retraction actions, continuously removing soil or rock material. When the real-time elevation coordinates drop to equal to or slightly less than the geometric target bottom elevation, a stop pressing signal is immediately issued, and the system automatically switches to bucket bottom trimming mode, maintaining the current elevation for horizontal leveling operations. As the excavator moves along the designed direction, repeating the aforementioned depth-controlled excavation actions at each location, a continuous trench with a bottom flatness conforming to the design straight-line reference vector is ultimately formed on the slope surface. This trench is the straight-line lattice beam foundation trench, and its bottom elevation strictly follows the geometrically corrected design requirements, eliminating the influence of unevenness on the original slope surface. For example, in actual operation, when the sensor detects that the bucket has reached the preset target depth after various corrections, the control unit coordinates the combined action of the boom and the forearm to make the bucket teeth move along the set horizontal trajectory, thereby using the optimal pressure parameters calculated in the previous steps to perform precise cutting, ensuring that the bottom of the excavated trench is flat and accurately meets the design requirements.

[0096] A slope trench excavation system for prefabricated quick-assembly lattice beams, the system comprising:

[0097] The geometric correction module obtains the sequence of discrete coordinate points on the slope surface and the standard length of the precast lattice beam. It calculates the Euclidean distance between corresponding adjacent coordinate points and accumulates it to obtain the arc length of the geodesic line on the slope surface. The difference between the arc length and the standard length of the precast lattice beam is used to construct a design straight line reference vector connecting the first and last coordinate points. The vertical distance from each discrete coordinate point to the design straight line reference vector is calculated to obtain the geometric correction depth parameter.

[0098] The interface recognition module collects bucket pressure data during the excavation process, maps it to soil penetration resistance values, calculates the difference to obtain resistance gradient values, and determines the geological interface locking depth based on the changes in resistance gradient values.

[0099] The elevation calculation module calculates the elevation of the bottom surface of the geometric target based on the elevation of the current excavation location and the geometric correction depth parameters. It also calculates the measured elevation of the soil-rock boundary by combining the geological interface locking depth, thus forming an excavation decision elevation pair.

[0100] The control and judgment module compares the numerical values ​​of the excavation decision elevation pairs, generates cutting control commands or overburden stripping control commands, and integrates them into an adaptive excavation control command set.

[0101] The trenching module is executed, which parses the set of adaptive excavation control commands and drives the bucket to perform crushing excavation or soil removal actions by adjusting the hydraulic pressure, thus forming a straight grid beam foundation trench.

[0102] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for excavating slope foundation trenches for prefabricated quick-assembly lattice beams, characterized in that, Includes the following steps: S1: Obtain the sequence of discrete coordinate points on the slope surface and the standard length of the precast lattice beam. Calculate the Euclidean distance between corresponding adjacent coordinate points and accumulate it to obtain the arc length of the geodesic line on the slope surface. Construct a design straight line reference vector connecting the first and last coordinate points based on the difference between the design straight line reference vector and the standard length of the precast lattice beam. Calculate the vertical distance from each discrete coordinate point to the design straight line reference vector to obtain the geometric correction depth parameter. S2: During the excavation process, the bucket pressure data is collected and mapped to the soil penetration resistance value. The resistance gradient value is calculated by difference. Based on the change of the resistance gradient value, the locking depth of the geological interface is determined. S3: Calculate the elevation of the bottom surface of the geometric target based on the current excavation location and the geometric correction depth parameter, and combine it with the geological interface locking depth to calculate the measured elevation of the soil-rock boundary, forming an excavation decision elevation pair; S4: Compare the numerical values ​​of the excavation decision elevation pairs, generate cutting control commands or overburden stripping control commands, and integrate them into an adaptive excavation control command set; S5: Analyze the set of adaptive excavation control instructions, and drive the bucket to perform crushing excavation or soil removal by adjusting the hydraulic pressure to form a straight grid beam foundation trench; The specific steps for obtaining the geometric correction depth parameters are as follows: S111: Obtain the sequence of discrete coordinate points on the slope surface distributed along the design direction, as well as the standard length of the precast lattice beam. Calculate the Euclidean distance between adjacent coordinate points in the sequence of discrete coordinate points on the slope surface. Accumulate multiple Euclidean distances and statistically obtain the arc length of the geodesic line on the slope surface corresponding to the slope surface. S112: Compare the arc length of the geodesic line on the slope surface with the standard length of the precast lattice beam. When the arc length of the geodesic line on the slope surface exceeds the standard length of the precast lattice beam, extract the first and last discrete coordinate points of the slope surface in the discrete coordinate point sequence and construct a design straight line reference vector connecting the first and last coordinate points. S113: Calculate the vertical distance of each discrete coordinate point in the sequence of discrete coordinate points on the slope surface relative to the design straight line reference vector, and mark the vertical distance as the geometric correction depth parameter corresponding to the discrete coordinate point; The specific steps for obtaining the geological interface locking depth are as follows: S211: Collect the feedback data from the bucket tooth pressure sensor when the excavator performs the downward digging action and map it into the soil penetration resistance value. Simultaneously collect the digging depth coordinates at the current moment, calculate the difference in soil penetration resistance value and the difference in digging depth coordinates between adjacent collection moments, and calculate the resistance gradient value based on the difference in soil penetration resistance value and the difference in digging depth coordinates. S212: The resistance gradient values ​​are used to form a resistance gradient value sequence and input into the Fisher ordered clustering algorithm to perform operations on the ordered sample sequence, calculate the optimal split point position of the resistance gradient value sequence, and extract the best hardness determination threshold to distinguish geological hardness characteristics based on the optimal split point position. S213: Compare the resistance gradient value collected and calculated in real time with the optimal hardness determination threshold, locate the excavation depth coordinates when the resistance gradient value first exceeds the optimal hardness determination threshold, and obtain the geological interface locking depth. The specific steps for obtaining the mining decision elevation pairs are as follows: S311: Obtain the horizontal coordinates of the current excavation location and match the corresponding discrete coordinates of the slope surface from the sequence of discrete coordinates of the slope surface, extract the corresponding elevation data, call the geometric correction depth parameter corresponding to the current excavation location, calculate the difference between the elevation data of the discrete coordinates of the slope surface and the geometric correction depth parameter, and obtain the elevation of the bottom surface of the geometric target. S312: Call the elevation data of the discrete coordinate points on the slope surface corresponding to the current excavation location, and combine it with the geological interface locking depth to calculate the difference between the elevation data of the discrete coordinate points on the slope surface and the geological interface locking depth, so as to obtain the measured elevation of the soil-rock boundary. S313: Combine the bottom elevation of the geometric target at the same excavation location with the measured elevation of the soil-rock boundary to establish an excavation decision elevation pair; The specific steps for obtaining the adaptive mining control command set are as follows: S411: Analyze the values ​​of the measured elevation of the soil-rock boundary and the elevation of the bottom surface of the geometric target from the excavation decision elevation pair, determine whether the measured elevation of the soil-rock boundary is greater than the elevation of the bottom surface of the geometric target, and generate a criterion for the relative relationship of elevation values. S412: Based on the relative elevation values, when the measured elevation of the soil-rock boundary is greater than the elevation of the bottom surface of the geometric target, a cutting control command is generated; when the measured elevation of the soil-rock boundary is less than or equal to the elevation of the bottom surface of the geometric target, a soil stripping control command is generated, thus obtaining a single-excavation mode execution command. S413: Encapsulate the cutting control command or the overburden stripping control command in the single excavation mode execution command into a standardized control signal format and output it as an adaptive excavation control command set. The specific steps for obtaining the linear lattice beam foundation trench are as follows: S511: If the adaptive excavation control command set includes a cutting control command, then activate the fuzzy PID control algorithm logic to determine to increase the hydraulic pressure; if the adaptive excavation control command set includes a cover soil stripping control command, then maintain the standard hydraulic pressure and determine the hydraulic equipment pressure regulation strategy. S512: Execute the hydraulic equipment pressure regulation strategy, calculate the required increase in hydraulic pressure using a fuzzy PID control algorithm, or directly lock the standard hydraulic pressure, adjust the output power of the excavator's hydraulic equipment, and generate bucket drive hydraulic pressure; S513: The excavator bucket is driven by hydraulic pressure to operate on the soil, continuously removing soil until the bottom elevation of the geometric target is reached and the excavation action is stopped, thus constructing a straight lattice beam foundation trench on the slope surface.

2. The method for excavating slope foundation trenches for prefabricated quick-assembly lattice beams according to claim 1, characterized in that, The process of mapping to soil penetration resistance values ​​is as follows: Obtain the pre-calibrated piston action area and the soil contact cross-sectional area of ​​the bucket teeth; The downward driving force transmitted to the end of the bucket is calculated based on the feedback data from the pressure sensor of the hydraulic cylinder of the excavator boom or stick and the piston action area. The soil penetration resistance value is calculated based on the value of the downward driving force and the cross-sectional area of ​​the soil contact.

3. The method for excavating slope foundation trenches for prefabricated quick-assembly lattice beams according to claim 1, characterized in that, To calculate the required increase in hydraulic pressure, the following formula is used: ； In the formula, The adaptive proportional gain coefficient at the current moment. The preset initial static proportional gain, To adjust the quantization factor for gain, This represents the total number of fuzzy rules activated at the current sampling time. Representing the The activation intensity of the activated rule, Representing the The single-point fuzzy output value corresponding to the consequent of the rule; Substituting the adaptive proportional gain coefficient at the current moment into the PID control law yields the hydraulic pressure amplitude that needs to be increased.

4. A slope trench excavation system for prefabricated quick-assembly lattice beams, characterized in that, The method for excavating slope foundation trenches for prefabricated quick-assembly lattice beams according to any one of claims 1-3, the system comprising: The geometric correction module obtains the sequence of discrete coordinate points on the slope surface and the standard length of the precast lattice beam. It calculates the Euclidean distance between corresponding adjacent coordinate points and accumulates it to obtain the arc length of the geodesic line on the slope surface. The difference between the arc length and the standard length of the precast lattice beam is used to construct a design straight line reference vector connecting the first and last coordinate points. The vertical distance from each discrete coordinate point to the design straight line reference vector is calculated to obtain the geometric correction depth parameter. The interface recognition module collects bucket pressure data during the excavation process, maps it to soil penetration resistance values, calculates the difference to obtain resistance gradient values, and determines the geological interface locking depth based on the changes in resistance gradient values. The elevation calculation module calculates the elevation of the bottom surface of the geometric target based on the elevation of the current excavation location and the geometric correction depth parameters, and calculates the measured elevation of the soil-rock boundary in combination with the geological interface locking depth to form an excavation decision elevation pair. The control and determination module compares the numerical values ​​of the excavation decision elevation pairs, generates cutting control commands or overburden stripping control commands, and integrates them into an adaptive excavation control command set. The trenching module is executed to parse the set of adaptive excavation control commands and drive the bucket to perform crushing excavation or soil removal actions by adjusting the hydraulic pressure, thereby forming a straight grid beam trench.

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