Method, system, and storage medium for calculating digging resistance for waterway working excavator

Abstract

The application discloses a kind of excavating resistance calculation method, system and storage medium for water area operation excavator, method includes following process: after adjusting each mechanism to set position, fixed and determine the initial geometric parameter of each mechanism of excavator at this time;The hydraulic resistance coefficient of operation water area is measured by towing test method, the oil pressure of each oil cylinder is obtained by sensor, the rotation angle of bucket oil cylinder, bucket rod, bucket rod oil cylinder and ship body, and the flow velocity of operation water area;Based on the above parameters, the dynamic force arm length of each oil cylinder and excavating resistance is calculated in real time, and the water force and its force arm;With the hinge point of bucket and bucket rod as the center of ellipse, the dynamic moment balance equation including all oil cylinder force, water force and flow disturbance compensation force is constructed, and the excavating resistance is solved in real time;The application can accurately reflect hydrodynamic effect, water disturbance and dynamic change of geometric parameter, and then realize accurate measurement of water area excavating resistance.

Description

Technical Field

[0001] This invention relates to excavators, and more particularly to a method, system, and storage medium for calculating the digging resistance of an excavator used in water operations. Background Technology

[0002] Water excavation projects (such as channel dredging and inland waterway pipeline laying) face complex fluid-soil coupling environments. Traditional land-based excavation resistance models have significant limitations in water applications: hydrodynamic effects alter the stress state of the equipment, hull sway causes dynamic changes in geometric parameters, and excavation resistance exhibits nonlinear characteristics due to fluid disturbances. Currently, the main methods for calculating and measuring water excavation resistance are as follows:

[0003] (1) Empirical formula method: Based on the land excavation model, the resistance is estimated by introducing a water density correction coefficient. This method ignores the dynamic effects of water flow and the dynamic changes in the excavator's attitude.

[0004] (2) Laboratory simulation method: The resistance of the scaled model is measured by water tank test, but this method is difficult to reproduce the fluid-structure interaction effect of the real working condition and cannot provide real-time feedback of construction data.

[0005] (3) Static mechanical analysis method: This method only establishes the static torque balance equation and does not consider the hull sway, unsteady fluid forces and real-time changes in geometric parameters.

[0006] All of these problems lead to discrepancies between the excavation resistance calculated and measured by the excavator when operating in water and the actual situation. This makes it difficult to accurately reflect the multi-physics coupling mechanism under real working conditions, resulting in low construction efficiency and potential safety hazards. Summary of the Invention

[0007] Purpose of the invention: The purpose of this invention is to provide a method, system, and storage medium for calculating the excavation resistance of excavators used in water operations, which can accurately reflect hydrodynamic effects, water disturbance, and dynamic changes in geometric parameters, thereby achieving accurate measurement of excavation resistance in water areas.

[0008] Technical solution: The method for calculating the digging resistance of an excavator used in water operations according to the present invention includes the following process:

[0009] After adjusting each mechanism of the excavator to the set position and fixing it, the initial geometric parameters of each mechanism of the excavator are measured at this time. The boom remains in this fixed state during operation.

[0010] The basic hydraulic resistance coefficient of the working water area is determined by the towing test method and then corrected to obtain the final hydraulic resistance coefficient. During the excavator operation, the oil pressure of the bucket cylinder, stick cylinder and boom cylinder, the rotation angle of the bucket cylinder, stick, stick cylinder and the hull on which the excavator is located, and the water flow speed of the working water area are obtained by sensors installed on each mechanism.

[0011] The dynamic lever arm length of each cylinder and digging resistance is calculated in real time based on the initial geometric parameters and rotation angles of each mechanism; the water force and its lever arm are calculated in real time based on the water flow velocity and hydraulic resistance coefficient.

[0012] Using the hinge point between the bucket and the stick as the moment center, a dynamic moment balance equation is constructed that includes all hydraulic cylinder forces, water forces, and water flow disturbance compensation forces, and the excavation resistance is solved in real time.

[0013] By measuring the foundation hydraulic resistance coefficient using a towing test method in actual operating waters and then correcting it, the final hydraulic resistance coefficient is obtained. Compared to laboratory simulation methods, this method more realistically reproduces the fluid-structure interaction effect under operating conditions. Furthermore, the water force can be calculated from this. Compared to traditional methods that ignore hydrodynamic effects, this method incorporates the water force into the final dynamic moment balance equation, improving the accuracy of the final geotechnical resistance calculation. Moreover, the water force calculated from the final hydraulic resistance coefficient is more accurate than the result of the foundation hydraulic resistance coefficient, further improving the accuracy of the final calculation. Real-time acquisition of oil pressure, rotation angle, and water flow velocity data through multiple sensors enables comprehensive dynamic perception of the operating status. Then, based on the initial... The collected data, including real-time data collected during operation, allows for real-time calculation of the dynamic lever arm, water force, and its lever arm. This reflects the dynamic effects of water flow and changes in the excavator's geometric parameters in real time. The dynamic moment balance equation constructed based on this can more realistically and accurately reflect the dynamic scene in actual excavation operations compared to the static moment equation. The excavation resistance obtained by this method is more accurate. Furthermore, this method introduces water flow disturbance compensation force into the dynamic moment balance equation, further realistically restoring the water flow dynamic effects under the operation scenario. In summary, this method not only considers the real-time changes in the excavator's geometric parameters but also the dynamic water flow dynamic effects, enabling it to more accurately calculate the excavator's excavation resistance in water excavation.

[0014] Preferably, the model ship is towed in at least one predetermined direction to travel at a predetermined speed at a constant speed, and the towing force on the model ship is recorded. The hydraulic foundation resistance coefficient is then calculated using the following formula.

[0015] ,

[0016] in, Based on the basic hydraulic resistance coefficient, For the towing force of the model ship, The density of the water in the operating area. For the speed of the model ship, The projected area of ​​the model ship in the direction perpendicular to the water flow;

[0017] The basic hydraulic resistance coefficient is corrected according to the following formula.

[0018] ,

[0019] in, The final hydraulic resistance coefficient is given by Fr, where Fr is the Froude number. And n are the flow velocity influence coefficients;

[0020] The formula for calculating Fr is:

[0021] ,

[0022] in, Let g be the water flow velocity in the work area, and g be the acceleration due to gravity. This refers to the length of the part of the boom that is submerged in the water.

[0023] Preferably, the formula for calculating the water force is as follows:

[0024]

[0025] in, Force acting on water; For water flow velocity, The projected area of ​​the part of the excavator submerged in water in the direction of the water force.

[0026] Calculate according to the following formula

[0027]

[0028] in, The surface area of ​​the portion of the excavator's boom that is submerged in water along its length.

[0029] Calculate according to the following formula

[0030]

[0031] in, and These represent the components of the water flow velocity in the vertical and horizontal directions, respectively. This refers to the rotation angle of the hull on which the excavator is located.

[0032] Preferably, the water flow disturbance compensation force is calculated according to the following formula.

[0033] ,

[0034] Where k is the empirical coefficient for water flow disturbance. The density of the water in the operating area. h represents the water flow velocity in the operating area, and h represents the depth of the excavator when it is working.

[0035] The formula for calculating k is:

[0036] ,

[0037] Where C is a coefficient related to the bucket type, and g is the acceleration due to gravity.

[0038] Preferably, the dynamic torque balance equation is as follows:

[0039]

[0040] in, To excavate resistance, , and These are the forces acting on the bucket cylinder, the stick cylinder, and the boom cylinder, respectively. , , , and These are the lever arms corresponding to the water action force, bucket cylinder action force, stick cylinder action force, boom cylinder action force, and digging resistance, respectively.

[0041] Preferably, the towing test involves towing the model ship against the direction of the current.

[0042] Preferably, the projected area of ​​the model boat in the direction perpendicular to the water flow is the same as the projected area of ​​the part of the excavator submerged in water in that direction.

[0043] Preferably, the shape and material of the model ship are matched with the carrier ship that carries the excavator.

[0044] The excavation resistance calculation system for excavators operating in water areas according to the present invention includes:

[0045] Initialization module: used to adjust and fix each mechanism of the excavator to the set position and measure the initial geometric parameters of each mechanism of the excavator at this time. The boom maintains this fixed state during operation.

[0046] Parameter measurement module: used to measure the hydraulic resistance coefficient of the working water area through the towing test method. During the excavator operation, the oil pressure of the bucket cylinder, stick cylinder and boom cylinder, the rotation angle of the bucket cylinder, stick, stick cylinder and the hull on which the excavator is located, and the water flow velocity of the working water area are obtained by sensors set on each mechanism.

[0047] Parameter calculation module: used to calculate the dynamic lever arm length of each cylinder and digging resistance in real time based on the acquired initial geometric parameters and rotation angles of each mechanism; and to calculate the water force and its lever arm in real time based on the water flow velocity and hydraulic resistance coefficient.

[0048] Excavation resistance solution module: Used to construct a dynamic moment balance equation that includes all hydraulic cylinder forces, water forces, and water flow disturbance compensation forces, with the hinge point between the bucket and the stick as the moment center, and solve the excavation resistance in real time.

[0049] The present invention provides a computer-readable storage medium for storing one or more programs, wherein the one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods described above.

[0050] Beneficial effects: Real-time dynamic calculation of the lever arm is achieved by using an inclinometer and initial geometric parameters, overcoming the distortion problem of traditional static geometric models. The hydraulic resistance coefficient based on the towing test foundation is introduced and corrected to obtain the final hydraulic resistance coefficient, which is then used to calculate the water force. In addition, the water flow disturbance compensation force is added, realizing the accurate quantification of the hydrodynamic effect. Therefore, this invention can accurately reflect the hydrodynamic effect, water disturbance, and dynamic changes of excavator geometric parameters. By solving the moment balance equation with the bucket and stick hinge points as the moment centers through the above dynamic parameters, the accuracy, timeliness, and engineering practicality of excavation resistance calculation in complex water environments can be significantly improved. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the overall process of the method of the present invention;

[0052] Figure 2 A schematic diagram showing the layout of the various measuring devices on the excavator;

[0053] Figure 3 A simplified diagram of the excavator's initial posture before operation;

[0054] Figure 4 A simplified diagram of the field test for the hydraulic resistance coefficient Cd;

[0055] Figure 5 A simplified diagram of the excavation mechanics model for underwater excavation by an excavator;

[0056] Figure 6 A simplified diagram of the lever arm calculation model for L1-L3 and Ld;

[0057] Figure 7 A simplified diagram for calculating the force F_water exerted by water and its lever arm L_w;

[0058] Figure 8 Error diagram of various working conditions and digging force benchmark value under water flow velocity of 0.8 m / s;

[0059] Figure 9 Error diagram of various working conditions and digging force benchmark value under water flow velocity of 1.2 m / s;

[0060] Figure 10 This is a schematic diagram of the topology of the system of the present invention. Detailed Implementation

[0061] like Figure 1 As shown, the method for calculating the digging resistance of an excavator used in water operations according to the present invention includes the following process:

[0062] Before conducting specific measurements and calculations, preliminary preparations are required:

[0063] Specifically, such as Figure 2 and 3 As shown, hydraulic pressure gauges and inclinometers are arranged, with hydraulic pressure gauges connected to the output terminals of the excavator's bucket cylinder CD, stick cylinder FG, and boom cylinder HI, respectively. Inclinometers are installed at the upper end of the bucket cylinder, the upper end of the stick, the rear end of the stick cylinder, and the outer surface of the hull. A Doppler current meter is installed on the lower half of the stick. Because this application pertains to conventional general-purpose excavators, the names and locations of their components are conventional and universal; therefore, individual component designations are not provided in the accompanying drawings.

[0064] The functions of each oil pressure gauge, inclinometer, and flow meter are explained in detail below:

[0065] Hydraulic pressure gauge 1: measures the output hydraulic pressure of the bucket cylinder in real time. The relationship between force and pressure is: F=P×S (F is the thrust, P is the output hydraulic pressure of the cylinder, and S is the cross-sectional area of ​​the cylinder); converted into bucket thrust, it is denoted as F1.

[0066] Oil pressure gauge 2: measures the output oil pressure of the boom cylinder in real time. The relationship between the force and pressure is: F=P×S; converted into boom thrust, it is recorded as F2.

[0067] Oil pressure gauge 3: measures the output oil pressure of the boom cylinder in real time. The relationship between the force and pressure is: F=P×S; converted into boom thrust, it is recorded as F3.

[0068] Inclinometer 1: measures the rotation angle of the bucket cylinder in real time. The rotation angle α1 determines the length of the lever arm L1.

[0069] Inclinometer 2: measures the rotation angle of the boom in real time, which is denoted as α2. α2 determines the length of the lever arm L3.

[0070] Inclinometer 3: measures the rotation angle of the boom cylinder in real time. The rotation angle is recorded as α3. α3 and α2 determine the length of the lever arm L2.

[0071] Inclinometer 4: Measures in real time the angle generated by the swaying of the hull during the operation of the excavator. The rotation angle is denoted as θ_hull, which is related to the direction of the force of the water flow.

[0072] Flow meter 1: measures the horizontal and vertical components of water flow in real time when the excavator is working.

[0073] After completing the preliminary preparations, calculate the excavation resistance according to the following process:

[0074] (1) such as Figure 3 As shown, the initial posture adjustment is as follows: after adjusting each mechanism of the excavator to the set position, fix it and measure the initial geometric parameters of each mechanism of the excavator at this time. The boom maintains this fixed state during operation.

[0075] Specifically, this includes ensuring that ∠DCL, ∠EFG, and ∠EHI are perpendicular. Note that the initial values ​​of these three angles can be adjusted according to the actual situation. Only ∠EHI remains constant throughout the excavation operation; the other two angles change in real time as the operation progresses. This is because the need for boom extension / retraction is relatively low in actual excavation operations; work can generally proceed without boom extension / retraction. Considering boom extension / retraction would significantly increase the complexity and uncertainty of the overall measurement and calculation. Therefore, keeping ∠EHI fixed allows for the re-measurement of all initial geometric parameters after boom adjustment, even if extension / retraction is required. This greatly reduces the amount of calculation and avoids calculation uncertainties compared to directly considering boom extension / retraction. After adjusting the posture, use a total station to measure A, B, C, D, E, F, G, H, I, L, and K in the diagram to obtain the initial coordinates. Subsequently, a rectangular coordinate system (X, Y) is established with point B as the origin (0,0) in order to obtain the initial conditions of AB, BD, BE, BF, ∠BAJ, ∠BDC, ∠EFB, and ∠HIB.

[0076] (2) The hydraulic resistance coefficient of the working water area is determined by the towing test method. During the excavator operation, the oil pressure of the bucket cylinder, stick cylinder and boom cylinder, the rotation angle of the bucket cylinder, stick, stick cylinder and the hull on which the excavator is located, and the water flow velocity of the working water area are obtained by the sensors set on each mechanism.

[0077] like Figure 4As shown, the towing test method specifically involves towing the model ship in at least one predetermined direction to make it move at a predetermined speed at a constant speed, and recording the towing force on the model ship. The basic hydraulic resistance coefficient is then calculated according to the following formula.

[0078] ,

[0079] in, Based on the basic hydraulic resistance coefficient, For the towing force of the model ship, The density of the water in the operating area. For the speed of the model ship, The projected area of ​​the model ship in the direction perpendicular to the water flow;

[0080] In actual use, multiple measurements are required, and the average value is taken as the final water resistance coefficient. In this embodiment, the model boat is towed against the direction of the water flow.

[0081] The basic hydraulic resistance coefficient is corrected according to the following formula.

[0082] ,

[0083] in, The final hydraulic resistance coefficient is given by Fr, where Fr is the Froude number. And n are the flow velocity influence coefficients;

[0084] The method for determining n is as follows:

[0085] In actual water flow, when an excavator performs excavation without contacting the soil at both high and low flow velocities (1.15~1.88 m / s), the excavation resistance F is... 挖 =(F1L1+F2L2+F 水 L w -F3L3) / L d +∆F=0; After changing the formula, F 水 =(F3L3-F1L1-F2L2-∆FL d ) / L w At this point, the formula can be used to calculate the hydrodynamic force F under the two flow velocities. 水 Use The hydraulic resistance coefficient, C, is calculated in reverse for both flow velocities. d-低速 and C d-高速 .

[0086] List the system of equations: Substituting the baseline value Cd0 and the two operating condition data, the flow velocity influence coefficients α and n can be calculated.

[0087] The formula for calculating Fr is:

[0088] ,

[0089] in, Let g be the water flow velocity in the work area, and g be the acceleration due to gravity. This refers to the length of the part of the boom that is submerged in the water.

[0090] Selection and testing requirements for the model ship:

[0091] Geometric similarity: The shape of the model ship should be geometrically similar to that of the actual ship in operation, or at least have a similar frontal cross-section shape and length-to-width ratio, preferably identical.

[0092] Surface characteristics: The surface material and roughness of the model ship should be as close as possible to the actual working ship hull (usually steel), preferably the same, in order to simulate similar frictional resistance characteristics.

[0093] Submersion depth: The draft of the model ship should simulate the average depth of an excavator submerged in water under typical working postures, ensuring that its underwater projected area is the same as or similar to that of the actual working conditions.

[0094] The hydraulic resistance coefficient is a relatively fixed constant. It fluctuates very little within a certain water range and can be approximated as a constant. By setting the model ship as described above, it can more closely approximate the actual operating conditions, and the measured hydraulic resistance coefficient is more accurate.

[0095] (3) Calculate the dynamic lever arm length of each cylinder and digging resistance in real time based on the initial geometric parameters and rotation angle of each mechanism; calculate the water force and its lever arm in real time based on the water flow velocity and hydraulic resistance coefficient.

[0096] like Figure 5-7 As shown, the specific calculation process is as follows:

[0097] 1) Calculation of the lever arm L1 corresponding to the force applied by the bucket cylinder:

[0098] Geometric calculations show that: L1 = BD × sin(∠BDC - α1); where BD and ∠BDC are initial measured values, and α1 is the real-time rotation angle value of the bucket cylinder.

[0099] 2) Calculation of the lever arm L2 corresponding to the force applied by the boom cylinder:

[0100] Since the stick is a rigid body, during the rotation of the stick around point E, point B moves to point B', and point F moves to point F'; therefore, BF = B'F', and ∠EFB = ∠EF'B'. Using geometric formulas and the initial measurement values ​​of the excavator's initial posture before digging, we can calculate: ∠1 = 180° - [180° - (90° - α3 + α2) + ∠EF'B'] = 90° + α2 - α3 - ∠EF'B'; then L2 = B'F' × sin(90° + α2 - α3 - ∠EF'B'); where B'F' and ∠EF'B' are initial measurement values, α2 is the real-time rotation angle of the stick, and α3 is the real-time rotation angle of the stick cylinder.

[0101] 3) Calculation of the lever arm L3 corresponding to the force applied by the boom cylinder:

[0102] When the excavator is in operation, if only the boom is rotated, the angle ∠HIB remains unchanged during the excavator's rotation; and ∠HIB can be calculated using the initial coordinates of H, B, and I. If only the stick is rotated, the stick rotates around point E. At this point, a new coordinate system (X', Y') is established with point E as the origin. The coordinates of point B in the coordinate system (X', Y') can then be calculated from the initial coordinates of E, B, and I and denoted as (a, b); the coordinates of point I are denoted as (c, d); and the motion coordinates B' of point B during the excavator's operation can be calculated using geometric relationships from the stick's rotation angle α2 and denoted as (e, f).

[0103] Then the equation of the line B'I is: ;

[0104] The distance to B'I is: ;

[0105] The distance BL from point B to line B'I is: ;

[0106] The distance to BI is: ; Therefore ∠3=arcsin(BL / BI); ∠2=∠HIB-∠3.

[0107] From the above derivation, we know that the lever arm L3 = B'I × sin(∠2).

[0108] 4) The lever arm L corresponding to the excavation resistance d Calculation:

[0109] From geometric calculations, we know that: Ld = AB × sin(∠BAJ); where AB and ∠BAJ are the initial measured values, therefore L d It is a constant value. The water disturbance compensation force is used to compensate for the excavation resistance, so its corresponding lever arm is also L. d .

[0110] 5) Water force F水 Calculation:

[0111] The force exerted by water can be calculated based on the hydraulic resistance coefficient. The formula for calculating the force exerted by water is as follows:

[0112]

[0113] in, Force acting on water; For water flow velocity, The projected area of ​​the part of the excavator submerged in water in the direction of the water force.

[0114] Calculate according to the following formula

[0115]

[0116] in, The surface area of ​​the portion of the excavator's boom that is submerged in water along its length.

[0117] The angle between the line connecting the center of the water flow force and moment and the center of the hydrodynamic pressure is calculated according to the following formula.

[0118]

[0119] in, and These represent the components of the water flow velocity in the vertical and horizontal directions, respectively. This refers to the rotation angle of the hull on which the excavator is located.

[0120] 6) The lever arm L corresponding to the force exerted by water w calculate:

[0121] The coordinates of the torque center point B can be obtained from the initial measurement; denoted as P. B The coordinates of the geometric center point K of the boom are determined by the segmented equivalent method, which involves discretizing the boom along its axis into several continuous regular cylindrical segments; the volume and centroid coordinates of each segment are calculated; finally, the total volume centroid of the entire boom is calculated using the volume weighted average formula, denoted as P. k The coordinates of the hydraulically equivalent point of action (i.e., the center of hydrodynamic pressure) W are P. w =P B +λ×(P K -P B λ is the correction factor for the hydrodynamic pressure center, ranging from 0.6 to 0.7. Through extensive field data and experimental calibration, a value of λ=0.65 yields good calculation accuracy for most water excavation conditions. Therefore, the length BW from the center of gravity B to the hydraulically equivalent point of action W can be calculated. Figure 7 It can be seen that the lever arm L of the water forcew =BW×sinψ.

[0122] (4) Using the hinge point between the bucket and the stick as the moment center, construct a dynamic moment balance equation that includes all hydraulic cylinder forces, water forces and water flow disturbance compensation forces, and solve the excavation resistance in real time.

[0123] The calculation principle of this invention is based on taking the connection point B between the bucket and the stick as the torque center. By taking the distance between the torque center B and the forces output by the three cylinders of the excavator, the water force during underwater excavation, the water disturbance compensation force, and the excavation resistance of the soil and rock, a torque balance equation is listed, and then the instantaneous excavation resistance of the excavator during operation is solved in real time.

[0124] The force compensating for water flow disturbance is calculated according to the following formula.

[0125] ,

[0126] Where k is the empirical coefficient for water flow disturbance. The density of the water in the operating area. h represents the water flow velocity in the operating area, and h represents the depth of the excavator when it is working.

[0127] The formula for calculating k is:

[0128] ,

[0129] Wherein, C is a coefficient related to the bucket type. The value of C is related to the bucket type. For general-purpose, narrow-tooth, and wide-plate buckets, the typical value ranges are 0.08, 0.06, and 0.1, respectively. In this invention, C is 0.08 (general-purpose bucket); g is the acceleration due to gravity.

[0130] The dynamic torque balance equation is

[0131]

[0132] in, To excavate resistance, , and These are the forces acting on the bucket cylinder, the stick cylinder, and the boom cylinder, respectively. , , , and These are the lever arms corresponding to the water action force, bucket cylinder action force, stick cylinder action force, boom cylinder action force, and digging resistance, respectively. All torques are vectors, with counterclockwise direction defined as positive and clockwise direction as negative.

[0133] like Figure 8 and 9As shown, to verify the accuracy and superiority of the model proposed in this invention in calculating the excavation resistance of water bodies, we designed and carried out a multi-condition comparative excavation test. The test aims to quantitatively analyze the influence of the hydraulic resistance coefficient correction term and the water flow disturbance compensation term on the final calculation results, and to comprehensively evaluate the engineering practicality of the model by comparing it with high-precision direct measurement values.

[0134] The experimental conditions are as follows:

[0135] 1. Operating water area: Select a typical section of the inland waterway with a water depth of 3-5 m and a bottom of silty clay.

[0136] 2. Equipment: A standard backhoe-type water excavator (equipped with a universal bucket) is used, and the complete sensor system described in this invention is installed.

[0137] 3. Benchmark value measurement: Install AFL-Z series column-type high-precision tension sensors at the tip of the bucket teeth to directly measure the actual digging resistance F_dig during the digging process in real time. The actual measurement is used as the benchmark value for evaluating the calculation accuracy.

[0138] 4. Working conditions: Under the same geological conditions, repeated excavation operations are carried out at water flow velocities of 0.8m / s and 1.2m / s respectively.

[0139] According to the present invention, the following four computational models are defined:

[0140] Table 1. Statistical table of definitions for each computational model

[0141] Operating conditions describe Torque balance equation Operating Condition 1 Complete model of the invention <![CDATA[F 挖 =(F1L1+F2L2+F 水 L w -F3L3) / L d +∆F]]> Operating Condition 2 <![CDATA[Using the basic hydrodynamic resistance coefficient C d0 for calculation]]> <![CDATA[F 挖 =(F1L1+F2L2+F （Cd0），水 L w -F3L3) / L d +∆F]]> Operating Condition 3 Considering only the water force, without considering the compensation term ∆F <![CDATA[F 挖 =(F1L1+F2L2+F 水 L w -F3L3) / L d ]]> Operating Condition 4 <![CDATA[Only consider the compensation term and do not consider the water acting force F 水 > <![CDATA[F 挖 =(F1L1+F2L2-F3L3) / L d +∆F]]>

[0142] Real-time data from a complete excavation cycle (approximately 20 seconds) is selected, and the calculated values ​​for each working condition are compared with the baseline value F. 挖，实测 The error comparison is as follows:

[0143] Table 2. Error characteristics of each working condition and digging force benchmark value under a water flow velocity of 0.8 m / s.

[0144] Operating conditions Maximum error value (KN) Average error (KN) Standard deviation (KN) <![CDATA[Reference value F 挖，实测 > / / / Operating Condition 1 (Complete Model) 0.496 0.301 0.093 <![CDATA[Operating condition 2 (using the basic hydraulic resistance coefficient C d0 ).]]> 1.049 0.698 0.165 Operating Condition 3 (Water Force Only) 3.267 1.695 0.630 Operating Condition 4 (Compensation Only) 9.069 4.659 2.411

[0145] Table 3. Error characteristics of each working condition and the benchmark value of digging force under a water flow velocity of 1.2 m / s.

[0146] Operating conditions Maximum error value (KN) Average error (KN) Standard deviation (KN) <![CDATA[Reference value F 挖，实测 > / / / Operating Condition 1 (Complete Model) 0.537 0.377 0.066 <![CDATA[Operating condition 2 (using the basic hydraulic resistance coefficient C d0 )]]> 1.085 0.779 0.127 Operating Condition 3 (Water Force Only) 2.583 1.356 0.554 Operating Condition 4 (Compensation Only) 8.407 3.064 2.612

[0147] Combining Tables 1-3, and Figure 8 and Figure 9 It can be known that:

[0148] Under condition 1 (complete model), the maximum error is 0.496 kN, the average error is 0.301 kN, and the standard deviation is 0.093 kN at a flow rate of 0.8 m / s; the maximum error is 0.537 kN, the average error is 0.377 kN, and the standard deviation is 0.066 kN at a flow rate of 1.2 m / s. The errors are minimal and stable at both flow rates, indicating that the model has high accuracy.

[0149] Condition 2 (without hydraulic coefficient correction) showed a significant increase in error; at a flow velocity of 0.8 m / s, the maximum error was 1.049 kN (2.1 times that of Condition 1), with an average of 0.698 kN (2.3 times); at a flow velocity of 1.2 m / s, the maximum error was 1.085 kN (2.0 times), with an average of 0.779 kN (2.1 times). This demonstrates the crucial importance of Froude number correction.

[0150] Under operating condition 3 (ignoring the compensation term ΔF), the error further increases; at a flow velocity of 0.8 m / s, the maximum is 3.267 kN (6.6 times that of operating condition 1), and the average is 1.695 kN (5.6 times); at a flow velocity of 1.2 m / s, the maximum is 2.583 kN (4.8 times), and the average is 1.356 kN (3.6 times). This proves that ΔF can effectively compensate for dynamic disturbances in the water flow.

[0151] Condition 4 (ignoring the water force Fwater) exhibits the largest error and most significant fluctuations; at a flow velocity of 0.8 m / s, the maximum is 9.069 kN (18.3 times that of Condition 1), with an average of 4.659 kN (15.5 times); at a flow velocity of 1.2 m / s, the maximum is 8.407 kN (15.7 times), with an average of 3.064 kN (8.1 times). This confirms that the water force is the core term in torque balance.

[0152] Comparing the error data under the two flow velocities, it can be seen that when the flow velocity increases from 0.8 m / s to 1.2 m / s, the maximum error of condition 1 only increases by 8.3%, and the standard deviation decreases. Although the errors of conditions 2, 3, and 4 also decrease, their absolute values ​​are still much higher than those of condition 1. This indicates that the complete model still maintains optimal error control capability under high-speed water flow conditions, demonstrating its good robustness.

[0153] In summary, the complete model has the highest accuracy. The combined introduction of hydraulic coefficient correction, compensation terms, and water action forces reduces the calculation error to 1 / 2 to 1 / 15 of that in the comparison case, effectively ensuring the accurate measurement of water excavation resistance.

[0154] like Figure 10 As shown, the digging resistance calculation system for excavators operating in water areas according to the present invention includes:

[0155] Initialization module: used to adjust and fix each mechanism of the excavator to the set position and measure the initial geometric parameters of each mechanism of the excavator at this time. The boom maintains this fixed state during operation.

[0156] Parameter measurement module: used to measure the hydraulic resistance coefficient of the working water area through the towing test method. During the excavator operation, the oil pressure of the bucket cylinder, stick cylinder and boom cylinder, the rotation angle of the bucket cylinder, stick, stick cylinder and the hull on which the excavator is located, and the water flow velocity of the working water area are obtained by sensors set on each mechanism.

[0157] Parameter calculation module: used to calculate the dynamic lever arm length of each cylinder and digging resistance in real time based on the acquired initial geometric parameters and rotation angles of each mechanism; and to calculate the water force and its lever arm in real time based on the water flow velocity and hydraulic resistance coefficient.

[0158] Excavation resistance solution module: Used to construct a dynamic moment balance equation that includes all hydraulic cylinder forces, water forces, and water flow disturbance compensation forces, with the hinge point between the bucket and the stick as the moment center, and solve the excavation resistance in real time.

[0159] The topology of this system can be divided into the following two layers:

[0160] First layer: Multiphysics sensing and data acquisition layer

[0161] Function: Comprehensively perceive the mechanical, kinematic, and hydrodynamic environment of underwater excavation operations.

[0162] Composition: ① Mechanical sensing group: 3 oil pressure sensors, installed on the hydraulic circuit of 3 oil cylinders, used to measure the oil pressure that generates F1, F2, F3.

[0163] ② Kinematic Sensing Group: 4 tilt sensors, used to measure the pressure of the bucket cylinder (α1), stick (α2), stick cylinder (α3), and hull (θ). 船体 The real-time angle is the basis for calculating all dynamic geometric relationships.

[0164] ③ Fluid dynamics sensor group: A Doppler current meter, installed on the lower half of the boom submerged in water, is used to measure the horizontal and vertical components (ν) of the water flow velocity in real time. 水平 ,ν 竖直 ).

[0165] Topology: These three sets of sensors are in parallel and together constitute all the input nodes of the system. Data is synchronously uploaded to the core processing layer via data lines.

[0166] Second layer: Core computing and processing layer

[0167] Function: Responsible for solving all core algorithms.

[0168] Composition: ① Central processing unit: the core of the system's overall control.

[0169] ② Initial parameters and calibration database: Stores mechanical geometric parameters (such as AB, BD, ∠BAJ, etc.) and environmental calibration parameters (ρ, C). d ):

[0170] ③ Dynamic lever arm calculation module: Based on α1, α2, α3 and the mechanical database, calculates the four mechanical lever arms L in real time. d , L1, L2, L3.

[0171] ④ Hydraulic calculation module: based on ν 水平 , ν 竖直 ,θ 船体 and ρ, C d Real-time calculation of water force F 水 And hydraulic lever arm L w .

[0172] ⑤ Water flow disturbance compensation module: Calculate the compensation amount ΔF based on the water flow velocity ν and the excavation depth h.

[0173] ⑥ Core solution module: Receives all force and lever arm data, and executes the final torque balance equation F 挖 =(F 水 L w +F1L1+F2L2-F3L3) / L d +ΔF, outputs the final soil and rock resistance.

[0174] Topology: This is a centralized processing topology. It coordinates the work of various dedicated computing modules. All computing modules rely on shared database parameters.

[0175] In addition to the above two layers, a third layer can be added: the result output and application layer.

[0176] Function: Use the calculation results for display and control to realize engineering value.

[0177] Components: Real-time resistance value F 挖 Display terminal: the most core output.

[0178] Topology: The core processing layer and this layer have a unidirectional output relationship. The units within this layer are parallel to each other.

[0179] The present invention provides a computer-readable storage medium for storing one or more programs, wherein the one or more programs include instructions that, when executed by a computing device, cause the computing device to perform the method described above.

Claims

1. A method for calculating the digging resistance of an excavator used in water operations, characterized in that, Includes the following processes: After adjusting each mechanism of the excavator to the set position and fixing it, the initial geometric parameters of each mechanism of the excavator are measured at this time. The boom remains in this fixed state during operation. The basic hydraulic resistance coefficient of the working water area is determined by the towing test method and then corrected to obtain the final hydraulic resistance coefficient. During the excavator operation, the oil pressure of the bucket cylinder, stick cylinder and boom cylinder, the rotation angle of the bucket cylinder, stick, stick cylinder and the hull on which the excavator is located, and the water flow speed of the working water area are obtained by sensors installed on each mechanism. The dynamic lever arm length of each cylinder and digging resistance is calculated in real time based on the initial geometric parameters and rotation angles of each mechanism; the water force and its lever arm are calculated in real time based on the water flow velocity and hydraulic resistance coefficient. Using the hinge point between the bucket and the stick as the moment center, a dynamic moment balance equation is constructed that includes all hydraulic cylinder forces, water forces, and water flow disturbance compensation forces, and the excavation resistance is solved in real time.

2. The method according to claim 1, characterized in that, The towing test method involves towing the model ship in at least one predetermined direction to make it move at a predetermined speed at a constant speed, and recording the towing force on the model ship. The basic hydraulic resistance coefficient is then calculated using the following formula. ， in, Based on the basic hydraulic resistance coefficient, For the towing force of the model ship, The density of the water in the operating area. For the speed of the model ship, The projected area of ​​the model ship in the direction perpendicular to the water flow; The basic hydraulic resistance coefficient is corrected according to the following formula. ， in, The final hydraulic resistance coefficient is given by Fr, where Fr is the Froude number. And n are the flow velocity influence coefficients; The formula for calculating Fr is: ， in, Let g be the water flow velocity in the work area, and g be the acceleration due to gravity. This refers to the length of the part of the boom that is submerged in the water.

3. The method according to claim 2, characterized in that: The formula for calculating the water force is: ， in, Force acting on water; The projected area of ​​the part of the excavator submerged in water in the direction of the water force. Calculate according to the following formula ， in, The surface area of ​​the portion of the excavator's boom that is submerged in water along its length. Calculate according to the following formula ， in, and These represent the components of the water flow velocity in the vertical and horizontal directions, respectively. This refers to the rotation angle of the hull on which the excavator is located.

4. The method according to claim 1, characterized in that: The water flow disturbance compensation force is calculated according to the following formula. ， Where k is the empirical coefficient for water flow disturbance. The density of the water in the operating area. h represents the water flow velocity in the operating area, and h represents the depth of the excavator when it is working. The formula for calculating k is: ， Where C is a coefficient related to the bucket type, and g is the acceleration due to gravity.

5. The method according to claim 1, characterized in that: The dynamic torque balance equation is: ， in, To excavate resistance, , and These are the forces acting on the bucket cylinder, the stick cylinder, and the boom cylinder, respectively. , , , and These are the lever arms corresponding to the water action force, bucket cylinder action force, stick cylinder action force, boom cylinder action force, and digging resistance, respectively.

6. The method according to claim 2, characterized in that: The towing test involves towing the model ship against the current.

7. The method according to claim 2, characterized in that: The projected area of ​​the model boat in the direction perpendicular to the water flow is the same as the projected area of ​​the part of the excavator submerged in water in that direction.

8. The method according to claim 7, characterized in that: The model ship's shape and material match those of the transport ship that carries the excavator.

9. A system for calculating the digging resistance of an excavator used in water operations, characterized in that, include: Initialization module: used to adjust and fix each mechanism of the excavator to the set position and measure the initial geometric parameters of each mechanism of the excavator at this time. The boom maintains this fixed state during operation. Parameter measurement module: used to measure the hydraulic resistance coefficient of the working water area through the towing test method. During the excavator operation, the oil pressure of the bucket cylinder, stick cylinder and boom cylinder, the rotation angle of the bucket cylinder, stick, stick cylinder and the hull on which the excavator is located, and the water flow velocity of the working water area are obtained by sensors set on each mechanism. Parameter calculation module: used to calculate the dynamic lever arm length of each cylinder and digging resistance in real time based on the acquired initial geometric parameters and rotation angles of each mechanism; Real-time calculation of water action force and its lever arm based on water flow velocity and hydraulic resistance coefficient; Excavation resistance solution module: Used to construct a dynamic moment balance equation that includes all hydraulic cylinder forces, water forces, and water flow disturbance compensation forces, with the hinge point between the bucket and the stick as the moment center, and solve the excavation resistance in real time.

10. A computer-readable storage medium for storing one or more programs, characterized in that: The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods according to claims 1 to 8.

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