Method and system for determining the time of changing the cutter of a tunnel boring machine

Abstract

This application relates to the field of electronic digital data processing, and particularly to a method and system for determining the timing of cutterhead replacement in a tunnel boring machine. The method and system provided by this application determine the cutterhead radius-corrected wear contribution advance based on theoretical and actual advance advances. Compared to determining the actual advance advance solely based on scanning data, this method considers the compensation amount for the depth of rock not penetrated due to cutterhead wear during the tunneling process within the expected advance advance. By determining the current value of the relative wear amount of the cutterhead based on the cutterhead radius-corrected wear contribution advance advance, it eliminates the error caused by the shortening of the trajectory line due to cutterhead wear in the advance advance calculation, making the determined wear amount more consistent with reality. Compared to existing methods that rely on experience to determine the cutterhead replacement timing, this method combines the actual advance advance, theoretical advance advance, and the current value of the relative wear amount to determine the cutterhead replacement timing, providing a data basis for determining the timing and making the timing determination more accurate and scientific.

Description

Technical Field

[0001] The embodiments of this application relate to the field of electronic digital data processing, and in particular to a method and system for determining the timing of cutterhead replacement in a tunnel boring machine. Background Technology

[0002] The statements herein are provided merely as background information in connection with this application and do not necessarily constitute prior art.

[0003] A full-face tunnel boring machine (MTBF) is a large-scale mechanical device used for excavating the entire face of a tunnel. During excavation, the cutterhead at the front of the MTBF faces the tunnel face. The roller cutters, mounted on the cutterhead, rotate and press into the rock mass under immense thrust, directly breaking the rock mass at the tunnel face through rolling and shearing.

[0004] During the construction of a full-face tunnel boring machine, the cutter head comes into direct contact with the rock mass. In hard, highly abrasive rock strata, the cutter head ring will wear down rapidly. This will directly lead to a reduction in tunneling efficiency and affect the construction progress due to the need for frequent machine shutdowns to replace the cutter head. Summary of the Invention

[0005] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0006] This application provides a method for determining the timing of cutter replacement in a tunnel boring machine, comprising the following steps: S10: scanning the tunnel face being excavated by the tunnel boring machine and obtaining scan data of the tunnel face; S20: determining the data of the tunnel face from the scan data; S30: determining the trajectory data of the cutter from the data of the tunnel face; S40: determining the theoretical advance of the cutter; S50: determining the actual advance of the cutter based on the trajectory data; S60: determining the cutter radius-corrected wear contribution advance based on the theoretical advance and the actual advance; S70: determining the current value of the relative wear of the cutter based on the cutter radius-corrected wear contribution advance; S80: determining the timing of cutter replacement based on the actual advance, the theoretical advance, and the current value of the relative wear of the cutter.

[0007] This application also provides a system for determining the timing of cutterhead replacement in a tunnel boring machine, comprising: a scanner configured to scan the tunnel face of the tunnel boring machine to obtain scan data of the tunnel face; and a processor receiving the scan data obtained from the scanner and configured to: determine data of the tunnel face from the scan data; determine the trajectory data of the cutterhead from the data of the tunnel face; determine the theoretical advance of the cutterhead; determine the actual advance of the cutterhead based on the trajectory data; determine the cutterhead radius-corrected wear contribution advance based on the theoretical advance and the actual advance; determine the current value of the relative wear of the cutterhead based on the cutterhead radius-corrected wear contribution advance; and determine the timing of cutterhead replacement based on the actual advance of the cutterhead, the theoretical advance of the cutterhead, and the current value of the relative wear.

[0008] The method for determining the cutterhead replacement timing of a tunnel boring machine (TBM) according to embodiments of this application determines the cutterhead radius correction wear contribution feed based on theoretical and actual feed. Compared to determining the actual feed solely based on scanning data, this method considers the compensation amount for the depth of rock not penetrated due to cutter wear during the tunneling process within the required feed. Furthermore, it determines the current value of the relative wear amount of the cutterhead based on the cutterhead radius correction wear contribution feed, eliminating errors in the feed calculation results caused by the shortening of the trajectory line due to cutter wear, thus making the determined wear amount more consistent with reality. Compared to existing methods that rely on experience to determine cutterhead replacement timing, the method provided by embodiments of this application combines the actual feed, theoretical feed, and current value of relative wear amount to determine the cutterhead replacement timing, providing a data foundation for determining the timing, making the timing judgment more accurate and scientific, and avoiding the ineffective costs incurred due to premature cutterhead replacement or the engineering risks caused by delayed cutterhead replacement.

[0009] The system for determining the cutter replacement timing of a tunnel boring machine, provided in the embodiments of this application, determines the cutter radius-corrected wear contribution feed based on theoretical and actual feed. It then determines the current value of the relative wear of the cutter based on this feed, and combines the theoretical feed, actual feed, and the current value of the relative wear to determine the cutter replacement timing. This provides a data foundation for determining the cutter replacement timing, making the timing more accurate and scientific, and avoiding unnecessary costs due to premature cutter replacement or engineering risks caused by delayed cutter replacement. Attached Figure Description

[0010] To further illustrate the above and other advantages and features of this application, the specific embodiments of this application will be described in more detail below with reference to the accompanying drawings. The drawings, together with the following detailed description, are included in and form a part of this specification. Elements having the same function and structure are indicated by the same reference numerals. It should be understood that these drawings only depict typical examples of this application and should not be considered as limiting the scope of this application.

[0011] Figure 1 This is a point cloud diagram of the working face provided in an embodiment of this application; Figure 2 The embodiments of this application provide for the... Figure 1 A schematic diagram of the point cloud at the working face after preprocessing; Figure 3 Yes Figure 2 A schematic diagram of the line point cloud obtained by cutting the point cloud of the pre-processed working face from the 0° direction; Figure 4 Yes Figure 2 A schematic diagram of the line point cloud obtained by cutting the point cloud of the pre-processed working face from a 45° direction; Figure 5 Yes Figure 2 A schematic diagram of the line point cloud obtained by cutting the point cloud of the pre-processed working face from a 90° direction; Figure 6 Yes Figure 2 A schematic diagram of the line point cloud obtained by cutting the point cloud of the pre-processed working face from a 135° direction; Figure 7 This is a schematic diagram of line and point cloud data of the working face provided in an embodiment of this application; Figure 8 This is a schematic diagram of the actual advance provided in the embodiments of this application; Figure 9 This is a schematic diagram illustrating the relationship between the wear contribution of the center cutter radius correction, the measured value of the relative wear of the center cutter, and the radius of the cutter head position of the center cutter, provided in an embodiment of this application. Figure 10 This is a schematic diagram showing the relationship between the wear contribution of the front cutter radius correction, the measured value of the relative wear of the front cutter, and the radius of the cutter head where the front cutter is located, provided in an embodiment of this application. Figure 11 This is a schematic diagram illustrating the relationship between the edge cutter radius correction wear contribution advance, the measured value of the relative wear of the edge cutter, and the radius of the edge cutter head position provided in the embodiments of this application. Detailed Implementation

[0012] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.

[0013] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0014] The following disclosure provides several different implementations or examples for carrying out this application. To simplify the disclosure of this application, specific examples of components and methods are described below. Of course, these are merely examples and are not intended to limit this application. In the description of the embodiments of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0015] Currently, cutter head replacement is still primarily based on manual experience. Operators use cutter head measuring gauges to measure each cutter head individually. However, there is no suitable standard for cutter head replacement. This method is highly subjective and lacks quantitative basis, often resulting in situations such as "replacing cutters before they become dull" or "excessively delaying cutter head replacement." Frequent or delayed cutter head replacements not only waste cutters but also reduce tunneling continuity, increase equipment downtime, and may even lead to cutter head imbalance or abnormal vibration, seriously affecting tunneling efficiency and safety.

[0016] To address the aforementioned problems, one embodiment of this application provides a method for determining the timing of cutter replacement in a tunnel boring machine, comprising the following steps: S10: scanning the tunnel face being excavated by the tunnel boring machine and obtaining scan data of the tunnel face; S20: determining the data of the tunnel face from the scan data; S30: determining the trajectory data of the cutter from the data of the tunnel face; S40: determining the theoretical advance of the cutter; S50: determining the actual advance of the cutter based on the trajectory data; S60: determining the cutter radius correction wear contribution advance based on the theoretical advance and the actual advance; S70: determining the current value of the relative wear of the cutter based on the cutter radius correction wear contribution advance; S80: determining the timing of cutter replacement based on the actual advance, the theoretical advance, and the current value of the relative wear of the cutter.

[0017] The method for determining the cutterhead replacement timing of a tunnel boring machine (TBM) according to embodiments of this application determines the cutterhead radius correction wear contribution feed based on theoretical and actual feed. Compared to determining the actual feed solely based on scanning data, this method considers the compensation amount for the depth of rock not penetrated due to cutter wear during the tunneling process within the required feed. Furthermore, it determines the current value of the relative wear amount of the cutterhead based on the cutterhead radius correction wear contribution feed, eliminating errors in the feed calculation results caused by the shortening of the trajectory line due to cutter wear, thus making the determined wear amount more consistent with reality. Compared to existing methods that rely on experience to determine cutterhead replacement timing, the method provided by embodiments of this application combines the actual feed, theoretical feed, and current value of relative wear amount to determine the cutterhead replacement timing, providing a data foundation for determining the timing, making the timing judgment more accurate and scientific, and avoiding the ineffective costs incurred due to premature cutterhead replacement or the engineering risks caused by delayed cutterhead replacement.

[0018] In some embodiments, in step S60, the hob radius correction wear contribution feed, the theoretical feed of the hob, and the actual feed of the hob conform to the following relationship: , For the cutting speed based on the hobbing cutter theory, This refers to the actual feed rate of the hobbing cutter. To replace the initial wear of the hob, The contribution of the hob radius to wear correction is determined by combining the initial wear amount of the replaced hob, the theoretical hob feed, and the actual hob feed. This allows for the preliminary determination of the contribution of the hob radius to wear correction, which in turn facilitates the subsequent determination of the current value of the relative wear amount of the hob.

[0019] If the cutterhead is planar, the theoretical cutter advance is constant. If the rock strata conditions are special, a conical cutterhead may be used. The cutterhead needs to be divided into center cutter, front cutter, and side cutter according to the cutterhead layout diagram. In this case, the theoretical cutter advance is represented as a piecewise function with the radius of the cutterhead position of the cutterhead as the independent variable.

[0020] In some embodiments, step S70 further includes the following steps: S71: determining the measured value of the relative wear of the cutterhead; S72: determining the radius of the cutterhead position where the cutterhead is located; S73: fitting and determining the relationship between the cutterhead radius-corrected wear contribution to the advance, the measured value of the relative wear of the cutterhead, and the radius of the cutterhead position where the cutterhead is located, as determined in step S60; S74: determining the current value of the relative wear of the cutterhead based on the relationship determined in step S73. Since the rotational linear velocity of the cutterheads at the center and edge of the conical cutterhead is different, their wear rates and contributions to tunneling are different. By establishing the relationship between the radius of the cutterhead position, the measured value of the relative wear, and the cutterhead radius-corrected wear contribution to the advance, the advance of each cutterhead can be specifically determined, avoiding incorrect judgments of its wear state due to different positions, and accurately quantifying the actual contribution of cutterheads at different positions on the cutterhead to the total advance due to differences in radius and wear degree.

[0021] In step S73, the relationship between the hob radius correction wear contribution feed, the measured value of the relative wear of the hob, and the radius of the hob's position on the cutter head conforms to the following formula: , To contribute to the advance of the hob radius to compensate for wear. Let R be the measured value of the relative wear of the hob, and R be the radius of the hob's position on the cutter head. a, b, c, d, e, f, m, and n are all fitting parameters. Although high-order polynomial linear regression fitting has high accuracy, too many high-order variables can even lead to overfitting of the surface. Therefore, the above method uses second-order variables in combination with exponential and logarithmic functions. This allows the linear, nonlinear, and asymptotic decay characteristics of hob wear to be expressed in a single equation, enabling the quantitative coupling relationship between hob wear and rock-breaking ability. This avoids the subjective problem of traditional manual judgment of hob wear based on experience.

[0022] In some embodiments, in step S73, the measurement value of the relative wear of the hob is... The radius R of the cutterhead position of the hob can be determined based on the record of the first cutter change at the beginning of tunneling. The radius R of the hob can be obtained from the cutterhead structure design drawing. The wear contribution of the hob radius correction is determined by step S60. By fitting the above data, the fitting parameters a, b, c, d, e, f, m and n can be obtained.

[0023] In the formula relating the wear contribution to the cutter radius correction, the measured value of the relative wear of the cutter, and the radius of the cutter head where the cutter is located, This represents the measured value of the relative wear of the hob. This is equivalent to obtaining the relationship between the relative wear of the hob, the wear contribution feed corrected by the hob radius, and the radius of the hob's position on the cutter head. When the wear contribution feed corrected by the hob radius and the radius of the hob's position on the cutter head are known, but the current value of the relative wear of the hob is unknown, the above expression can be used to determine the current value of the relative wear of the hob.

[0024] In some embodiments, in step S74, the relationship between the current value of the relative wear amount and the change in the feed rate of the cutter radius correction wear can be obtained based on the fitting parameters determined in step S73 and the radius R of the cutter head where the hob is located, so as to back-determine the current value of the relative wear amount, so that the current value of the relative wear amount does not need to be manually recorded after the first tool change.

[0025] Figure 9 This is a schematic diagram illustrating the relationship between the wear contribution to the feed rate corrected by the center cutter radius, the measured value of the relative wear of the center cutter, and the radius of the cutterhead position where the center cutter is located, provided in an embodiment of this application. Figure 10 This is a schematic diagram illustrating the relationship between the wear contribution to the feed rate of the front cutter radius correction, the measured value of the relative wear of the front cutter, and the radius of the cutter head where the front cutter is located, according to embodiments of this application. Figure 11 This is a schematic diagram illustrating the relationship between the edge cutter radius correction wear contribution feed, the measured value of the relative wear of the edge cutter, and the radius of the edge cutter head position provided in embodiments of this application. In some embodiments, such as... Figures 9-11 As shown, the wear contribution of the hob radius correction obtained by fitting the hob at different positions on the conical cutter head is different, indicating that the actual contribution of the hob at different positions on the conical cutter head to the total feed is different due to the difference in radius and the degree of wear.

[0026] In some embodiments, the fitting accuracy of step S73 can be compared based on the scan data obtained in step S10. For example, the coefficient of determination and root mean square error can be determined as parameters to measure the fitting accuracy, so as to verify the fitting accuracy of the relationship determined in step S73.

[0027] In some embodiments, the determination coefficient can be determined in the following manner: , As the coefficient of determination, The measured value contributing to the advance of the hob radius correction wear. The wear correction value for the hob radius determined by the relation contributes to the predicted footage. is the average of the measured values, n is the number of data points, i is the data index, the denominator represents the total variance of the original data, and the numerator represents the sum of squared residuals.

[0028] In some embodiments, the root mean square error can be determined in the following manner: , The measured value contributing to the advance of the hob radius correction wear. The wear correction value for the hob radius determined by the relation contributes to the predicted footage. is the square root of the squared mean of the residuals, representing the average deviation between the predicted and measured values, where n is the number of data points and i is the data index.

[0029] In some embodiments, in step S80, if the ratio of the actual feed of the hob to the theoretical feed of the hob is determined to be less than a predetermined value, it is determined that the hob needs to be replaced. The ratio of the actual feed to the theoretical feed takes into account the changes in the hob trajectory depth and cutting width, and can reflect the rock-breaking efficiency and wear degree of the hob.

[0030] In some embodiments, when the ratio of actual feed to theoretical feed decreases significantly or reaches a set threshold, the current value of the relative wear of the hob determined in step S74 can be used to determine whether the hob has failed or needs to be replaced, thereby providing a quantitative basis for determining when to replace the hob.

[0031] In some embodiments, when the ratio of actual feed to theoretical feed is approximately equal to 1, the cutter is in an ideal rock-breaking state; when the ratio of actual feed to theoretical feed is less than 0.9, it indicates that the rock-breaking ability of the cutter has significantly decreased, and the cutter has already experienced a certain amount of wear; when the ratio of actual feed to theoretical feed is less than 0.75, the cutter is judged to be a blunt or damaged cutter, and the cutter is close to failure; when the ratio of actual feed to theoretical feed is equal to 0, it indicates that there may be a point cloud missing situation, which means that the cutter at this corresponding position may be abnormally damaged and needs to be inspected and replaced in time.

[0032] In some embodiments, for a conical cutterhead, the ratio of actual feed to theoretical feed of the cutter may differ at different positions. Calculating the ratio of actual to theoretical feed by selecting multiple adjacent points at the corresponding cutter position, and comparing the number and accuracy of the point cloud with the cutting edge width, can also reflect the cutter wear. This provides a comprehensive reflection of the changes in rock-breaking efficiency of the cutter at different positions.

[0033] In some embodiments, the relationship between the ratio of actual feed to theoretical feed and time can also be determined to achieve dynamic monitoring of the hob performance degradation law. Through the time-series change trend reflected by it, the wear acceleration zone and failure critical point can be identified, thereby making the basis for tool replacement judgment more scientific.

[0034] In some embodiments, step S20 further includes the following steps: S21: generating point cloud data of the tunnel face from the scanned data; S22: cutting the point cloud data at predetermined intervals and from different angles; S23: determining the line point cloud data of the tunnel face from the point cloud data obtained from the cutting. By cutting the point cloud data of the tunnel face from different angles, the surface point cloud data can be converted into a large amount of line point cloud data, thereby obtaining a two-dimensional profile of complex three-dimensional trajectory lines, which facilitates more accurate extraction of the trajectory line features formed by the hobbing cutter on the tunnel face.

[0035] In some embodiments, in step S21, the point cloud data of the working face can be preprocessed, for example, by denoising, filtering, and cropping operations, to remove non-working face areas (e.g., the cutter head portion) and retain only the effective scan data of the working face, providing a high-quality data foundation for subsequent hobbing trajectory line extraction and geometric analysis.

[0036] Figure 1 This is a point cloud diagram of the working face provided in an embodiment of this application. Figure 2 The embodiments of this application provide for the... Figure 1 A schematic diagram of the point cloud at the working face after preprocessing. In some embodiments, such as... Figure 1 As shown, the scanned point cloud of the tunnel face presents an approximately circular tunneling cross-section, but the cross-section near the center of this approximately circular shape is more fragmented, and the cutter trajectory is incomplete; while as... Figure 2 As shown, in the case of Figure 1 After preprocessing, the shape of the tunnel face becomes a more regular circle. Figure 1 The irrelevant area on the outer periphery of the working face has also been removed, and Figure 2 The cross-section near the center of the circle becomes complete, and the hobbing trajectory is clear and regular. Preprocessing the scanning data of the working face can make the cross-section complete and clear, which is convenient for further processing.

[0037] Figure 3 Yes Figure 2 A schematic diagram of the line point cloud obtained by cutting the pre-processed point cloud of the working face from the 0° direction. Figure 4 Yes Figure 2 A schematic diagram of the line point cloud obtained by cutting the pre-processed point cloud of the working face at a 45° angle. Figure 5 Yes Figure 2 A schematic diagram of the line point cloud obtained by cutting the pre-processed point cloud of the working face at a 90° angle. Figure 6 Yes Figure 2 A schematic diagram of a line point cloud obtained by cutting the pre-processed point cloud of the working face at a 135° angle. In some embodiments, such as... Figures 3-6As shown, in step S22, point cloud data can be cut at predetermined intervals (e.g., 1 mm) from the directions of 0°, 45°, 90° and 135° respectively. Since the angles of 0°, 45°, 90° and 135° are perpendicular and symmetrical to each other, omissions caused by deviation of any trajectory line can be avoided, and the trajectory line direction can be verified from multiple directions.

[0038] In some embodiments, in step S10, a three-dimensional laser scanner can be used to scan the tunnel face, which can achieve full coverage scanning of the tunnel face in a non-contact context. It can perform high-precision imaging of the tunnel face after each tunneling cycle without interfering with the tunneling construction. Compared with the traditional method of manually inspecting and measuring the cutter head, it can achieve three-dimensional reconstruction of the entire tunnel face in a short time, reducing human error and safety risks.

[0039] In some embodiments, in step S10, the scanning data of the tunnel face should cover all hob trajectory line areas and ensure sufficient point density and measurement accuracy to reflect the microscopic morphological characteristics of the tunnel face.

[0040] Figure 7 This is a schematic diagram of line and point cloud data of the working face provided in an embodiment of this application. Figure 8 This is a schematic diagram of the actual advance provided in the embodiments of this application. In some embodiments, such as Figure 7 and Figure 8 As shown, in step S50, the line point cloud data of the working face obtained in step S23 can be rigidly translated into a coordinate system to obtain... Figure 8 Compared to projection, this method can preserve the authenticity of line and point cloud data and avoid distortion in subsequent processing.

[0041] Another embodiment of this application provides a system for determining the timing of cutterhead replacement in a tunnel boring machine, comprising: a scanner configured to scan the tunnel face of the tunnel boring machine to obtain scan data of the tunnel face; and a processor receiving the scan data obtained from the scanner and configured to: determine data of the tunnel face from the scan data; determine the trajectory data of the cutterhead from the data of the tunnel face; determine the theoretical advance of the cutterhead; determine the actual advance of the cutterhead based on the trajectory data; determine the cutterhead radius-corrected wear contribution advance based on the theoretical advance and the actual advance; determine the current value of the relative wear of the cutterhead based on the cutterhead radius-corrected wear contribution advance; and determine the timing of cutterhead replacement based on the actual advance of the cutterhead, the theoretical advance of the cutterhead, and the current value of the relative wear.

[0042] The system for determining the cutter replacement timing of a tunnel boring machine, provided in the embodiments of this application, determines the cutter radius-corrected wear contribution feed based on theoretical and actual feed. It then determines the current value of the relative wear of the cutter based on this feed, and combines the theoretical feed, actual feed, and the current value of the relative wear to determine the cutter replacement timing. This provides a data foundation for determining the cutter replacement timing, making the timing more accurate and scientific, and avoiding unnecessary costs due to premature cutter replacement or engineering risks caused by delayed cutter replacement.

[0043] In some embodiments, the processor is further configured such that the hob radius correction wear contribution feed, the theoretical feed of the hob, and the actual feed of the hob conform to the following relationship: , For the cutting speed based on the hobbing cutter theory, This refers to the actual feed rate of the hobbing cutter. To replace the initial wear of the hob, The contribution of the hob radius to wear correction is determined by combining the initial wear amount of the replaced hob, the theoretical hob feed, and the actual hob feed. This allows for the preliminary determination of the contribution of the hob radius to wear correction data, which in turn helps determine the current value of the relative wear amount of the hob.

[0044] If the cutterhead is planar, the theoretical cutter advance is constant. If the rock strata conditions are special, a conical cutterhead may be used. The cutterhead needs to be divided into center cutter, front cutter, and side cutter according to the cutterhead layout diagram. In this case, the theoretical cutter advance is represented as a piecewise function with the radius of the cutterhead position of the cutterhead as the independent variable.

[0045] In some embodiments, the processor is further configured to: determine a measured value of the relative wear of the cutterhead; determine the radius of the cutterhead position where the cutterhead is located; fit a relationship between the cutterhead radius-corrected wear contribution to the advance, the measured value of the relative wear of the cutterhead, and the radius of the cutterhead position where the cutterhead is located; and determine the current value of the relative wear of the cutterhead based on the relationship. Since the rotational linear velocity of the cutterheads at the center and edge of the conical cutterhead differs, their wear rates and contributions to tunneling differ. By establishing a relationship between the radius of the cutterhead position, the measured value of the relative wear, and the cutterhead radius-corrected wear contribution to the advance, the advance of each cutterhead can be specifically determined, avoiding incorrect judgments of its wear state due to different positions, and accurately quantifying the actual contribution of cutterheads at different positions on the cutterhead to the total advance due to differences in radius and wear degree.

[0046] In some embodiments, the processor is further configured such that the relationship between the hob radius correction wear contribution feed, the measured value of the relative wear of the hob, and the radius of the hob's position on the cutter head conforms to the following formula: , To contribute to the advance of the hob radius to compensate for wear. Let R be the measured value of the relative wear of the hob, and R be the radius of the hob's position on the cutter head. a, b, c, d, e, f, m, and n are all fitting parameters. Although high-order polynomial linear regression fitting has high accuracy, too many high-order variables can lead to overfitting of the surface. Therefore, the above method uses second-order variables in combination with exponential and logarithmic functions. This allows the linear, nonlinear, and asymptotic decay characteristics of hob wear to be expressed in a single equation, enabling the quantitative coupling relationship between hob wear and rock-breaking ability. This avoids the subjective problem of traditional manual judgment of hob wear based on experience.

[0047] In some embodiments, the measurement value of the relative wear of the hob The radius R of the cutterhead position of the hobbing cutter can be determined based on the record of the first cutter change at the beginning of tunneling. It can be obtained from the cutterhead structure design drawing. By fitting the above data, the fitting parameters a, b, c, d, e, f, m and n can be obtained.

[0048] In some embodiments, the relationship between the current value of the relative wear amount and the change in the wear contribution of the cutter radius correction can be obtained based on the fitting parameters determined above and the radius R of the cutter head where the hob is located, so as to back-determine the current value of the relative wear amount, so that the current value of the relative wear amount does not need to be manually recorded after the first tool change.

[0049] In some embodiments, the fitting accuracy can be compared based on the scanning data obtained from the scanned document. For example, the coefficient of determination and root mean square error can be determined as parameters to measure the fitting accuracy, so as to verify the fitting accuracy of the above relationship.

[0050] In some embodiments, the determination coefficient can be determined in the following manner: , As the coefficient of determination, The measured value contributing to the advance of the hob radius correction wear. The wear correction value for the hob radius determined by the relation contributes to the predicted footage. is the average of the measured values, n is the number of data points, i is the data index, the denominator represents the total variance of the original data, and the numerator represents the sum of squared residuals.

[0051] In some embodiments, the root mean square error can be determined in the following manner: , The measured value contributing to the advance of the hob radius correction wear. The wear correction value for the hob radius determined by the relation contributes to the predicted footage. is the square root of the squared mean of the residuals, representing the average deviation between the predicted and measured values, where n is the number of data points and i is the data index.

[0052] The method and system for determining the timing of cutterhead replacement for tunnel boring machines provided in the embodiments of this application can reduce the number of times personnel enter the space in front of the cutterhead and reduce the risk of operation in high temperature and narrow environment; at the same time, by accurately grasping the rock breaking ability and wear state of the cutterhead, the cutterhead replacement strategy can be optimized by region and stage, which can significantly improve the continuity of tunneling and the utilization rate of equipment.

[0053] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0054] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A method for determining the timing of cutterhead replacement in a tunnel boring machine, characterized in that, It includes the following steps: S10: Scan the tunnel face being excavated by the tunnel boring machine and obtain scan data of the tunnel face; S20: Determine the data of the working face from the scan data; S30: Determine the trajectory data of the hob from the data of the working face; S40: Determine the theoretical feed rate of the hob; S50: Determine the actual feed of the hob based on the trajectory data; S60: Determine the cutter radius correction wear contribution cutter advance based on the theoretical advance and the actual advance; S70: Based on the wear contribution feed rate corrected by the hob radius, determine the current value of the relative wear amount of the hob; S80: Determine the timing for changing the hob based on the actual feed of the hob, the theoretical feed of the hob, and the current value of the relative wear. In step S60, The wear contribution feed rate of the hob radius correction, the theoretical feed rate of the hob, and the actual feed rate of the hob conform to the following relationship: ， For the cutting speed based on the hobbing cutter theory, This refers to the actual feed rate of the hobbing cutter. To replace the initial wear of the hob, This contributes to the advance rate for hob radius correction wear. Step S70 also includes the following steps: S71: Determine the measured value of the relative wear amount of the hob; S72: Determine the radius of the cutter head where the hob is located; S73: Fitting and determining the relationship between the cutter radius correction wear contribution advance, the measured value of the relative wear of the cutter, and the radius of the cutter head position of the cutter determined in step S60; S74: Determine the current value of the relative wear amount of the hob based on the relationship determined in step S73; In step S73, the relationship between the cutter radius correction wear contribution feed, the measured value of the relative wear of the cutter, and the radius of the cutter head position of the cutter conforms to the following formula: ， To contribute to the advance of the hob radius to compensate for wear. R is the measured value of the relative wear of the hob, R is the radius of the position of the hob on the cutter head, and a, b, c, d, e, f, m and n are all fitting parameters.

2. The method according to claim 1, characterized in that, In step S80, if the ratio of the actual feed of the hob to the theoretical feed of the hob is less than a predetermined value, it is determined that the hob needs to be replaced.

3. The method according to claim 1 or 2, characterized in that, Step S20 also includes the following steps: S21: Generate point cloud data of the working face from the scan data; S22: Cut the point cloud data at predetermined intervals and from different angles; S23: Determine the line point cloud data of the working face from the point cloud data obtained from the cutting.

4. A system for determining the timing of cutterhead replacement in a tunnel boring machine, characterized in that, It includes: A scanning device, configured to scan the tunnel face being excavated by the tunnel boring machine, to obtain scanning data of the tunnel face; A processor that receives scan data obtained from the scanner and is configured to: The data of the working face are determined from the scan data; The trajectory data of the hobbing cutter is determined from the data of the working face; Determine the theoretical feed rate of the hob; Based on the trajectory data, the actual feed rate of the hob is determined; Based on the theoretical feed and the actual feed, determine the feed of the hob with the corrected wear contribution due to the hob radius; based on the feed of the hob with the corrected wear contribution due to the hob radius, determine the current value of the relative wear amount of the hob. The timing for changing the hob is determined based on the actual feed of the hob, the theoretical feed of the hob, and the current value of the relative wear. The processor is also configured to: The wear contribution feed rate of the hob radius correction, the theoretical feed rate of the hob, and the actual feed rate of the hob conform to the following relationship: ， For the cutting speed based on the hobbing cutter theory, This refers to the actual feed rate of the hobbing cutter. To replace the initial wear of the hob, This contributes to the advance rate for hob radius correction wear. The processor is also configured to: Determine the measured value of the relative wear of the hob; Determine the radius of the position of the hob on the cutter head; The relationship between the wear contribution of the hob radius correction, the measured value of the relative wear of the hob, and the radius of the hob's position on the cutter head is determined by fitting. Based on the relationship, determine the current value of the relative wear of the hob; The processor is also configured to: The relationship between the wear contribution of the hob radius correction, the measured value of the relative wear of the hob, and the radius of the hob's position on the cutter head conforms to the following formula: ， To contribute to the advance of the hob radius to compensate for wear. R is the measured value of the relative wear of the hob, R is the radius of the position of the hob on the cutter head, and a, b, c, d, e, f, m and n are all fitting parameters.

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