Continuous ship unloader material flow stable control system and method

Abstract

The invention provides a material flow stability control system and method for a continuous ship unloader, and the method comprises the following steps: S1, recognizing the contour of a material in each chain bucket which is continuously lifted, and obtaining material morphology point cloud data; s2, de-noising the material morphology point cloud data by adopting a statistical filtering method; s3, performing plane fitting on the de-noised material morphology point cloud data by adopting a least square method to obtain a plane equation of the material surface; s4, performing curved surface integral on the plane equation of the material surface and a pre-obtained chain bucket bottom surface equation to obtain a material volume; s5, obtaining the material load in the chain bucket according to the material volume and the specific gravity, and calculating the instantaneous material flow value of the system according to the parameters such as the current chain bucket lifting rate; and S6, comparing the instantaneous material flow with a preset material flow, and timely adjusting a material taking process strategy. According to the method, the material taking strategy is dynamically adjusted, and it is ensured that the ship unloader efficiently carries out ship unloading operation under stable material flow.

Description

Technical Field

[0001] The invention relates to the technical field of port ship unloaders, and in particular to a material flow stabilization control of a chain bucket type continuous ship unloader. Background Art

[0002] The continuous ship unloader is energy-saving, highly efficient and environmentally friendly. It is a large-scale special ship unloading equipment for bulk material terminals.

[0003] At present, when continuous ship unloaders are retrieving materials, they mainly rely on the driver to observe the chain bucket excavation situation and adjust the mechanism action combination and cross-cutting speed according to experience to achieve material flow control. This requires a high level of driver skills and high labor intensity in operation. It is difficult to ensure continuous and stable material retrieving of the equipment, and cannot meet the needs of efficient turnover and automated material retrieving control of port terminals. Summary of the invention

[0004] The present invention provides a material flow stabilization control system and method for a continuous ship unloader, which realize automatic stabilization control of the material flow during the material taking operation of the continuous ship unloader.

[0005] The technical means adopted by the present invention are as follows:

[0006] A material flow stabilization control system for a continuous ship unloader includes the following contents:

[0007] Laser scanning module: used to scan the material contours in each chain bucket to obtain material shape point cloud data;

[0008] Data acquisition module: used to collect material morphology point cloud data of each chain bucket. In order to ensure the accuracy of the calculation results and the processing efficiency, the collected material morphology point cloud data is sent to the data processing module;

[0009] Data processing module: used to denoise the material morphology point cloud data through statistical filtering method, and obtain the filling rate of the material inside the chain bucket and the lifting material flow after fitting processing;

[0010] Decision-making module: used to compare the lifting material flow with the preset material flow, and adjust the material filling rate in the chain bucket through the digging module;

[0011] GUI module: used to display the material load dug by each chain bucket through a list data structure.

[0012] Excavation module: The material reclaiming head is controlled to run horizontally in the cabin through the linkage of horizontal movement, trolley, rotation of the material reclaiming head and linkage lifting mechanism, and the chain bucket is used to continuously excavate the materials and transport them to the dock belt.

[0013] A method for stabilizing material flow of a continuous ship unloader comprises the following steps:

[0014] S1. Perform laser scanning on the material contours in each chain bucket that is continuously lifted to obtain material morphology point cloud data;

[0015] S2. Use statistical filtering method to denoise the material morphology point cloud data;

[0016] S3. Use the least square method to perform plane fitting on the denoised material morphology point cloud data to obtain the plane equation of the material surface;

[0017] S4, performing surface integration of the plane equation of the material surface and the chain bucket bottom equation obtained in advance to obtain the volume of the material;

[0018] S5. Based on the standard volume of the chain bucket and the material volume, the filling rate of the material inside the chain bucket is obtained, and the instantaneous material flow is calculated according to parameters such as the preset material specific gravity and the current chain bucket lifting rate;

[0019] S6. Compare the instantaneous lifting load with the preset material flow value to determine the current material flow state, and then adjust the cross-cutting speed and digging depth of the material taking head to achieve dynamic closed-loop control of the material taking flow rate.

[0020] Furthermore, S2 specifically includes the following steps:

[0021] The statistical filtering method determines whether a point is a noise point by calculating the number of neighboring points of each point in the material morphology point cloud data. Assuming that the point cloud data is P = {p1, p2, ..., p n}, where p i Represents the coordinates of the i-th point. For each point p i , calculate the average distance of its k nearest neighbors:

[0022]

[0023] Among them, p i,j represents the jth neighbor point of the i-th point, and ||·|| represents the Euclidean distance;

[0024] Compute the mean distance and standard deviation for all points:

[0025]

[0026] Set the threshold α, the average distance exceeds The points are regarded as noise points and the noise points are removed.

[0027] Furthermore, S3 specifically includes the following steps:

[0028] Solve the fitting plane equation ax+by+cz+d=0 by the least squares method;

[0029] Given a denoised point cloud dataset Construct the design matrix A and observation vector p = [a, b, c] T :

[0030]

[0031] p=(A T A) -1 A T b

[0032] Perform singular value decomposition on the design matrix A and the observation vector p:

[0033]

[0034] Get the plane equation of the material surface:

[0035]

[0036] Furthermore, S4 specifically includes the following steps:

[0037] The pre-obtained chain bucket bottom equation is:

[0038] z=z base ;

[0039] Perform surface integral on the plane equation of the material surface and the chain bucket bottom equation:

[0040]

[0041] Among them, A is the integration area, a i j is the fitting coefficient, n and m are the highest powers of the polynomial.

[0042] Furthermore, in S5:

[0043] According to the preset material specific gravity ρ, calculate the current material flow value Q:

[0044]

[0045] Among them, i is the number of chain buckets, L is the telescopic distance, and H is the distance from the root of the reclaiming head to the center of the sprocket;

[0046] is the filling rate of the chain bucket,

[0047] Furthermore, in S5, in the calculation of the overall lifting load, a list data structure is used to store the excavation load of each chain bucket. The load storage quantity is the number of chain buckets in the lifting stage. The material load data set is moved in a container-like manner. After each chain bucket excavation, the material load is added to the end of the list while the data at the head of the list overflows, so that the number of data in the data set is always constant, and the total material load in the current data set is calculated through a real-time accumulation algorithm.

[0048] Furthermore, S6 specifically includes the following steps:

[0049] When the actual material flow Q act Greater than the preset material flow Q set When the actual material flow Q act Less than the preset material flow Q set When the chain bucket approaches the minimum safe distance d from the chain bucket to the bottom of the cabin, first increase the cross-cutting speed and then increase the excavation depth; min The digging depth does not change.

[0050] Compared with the prior art, the present invention has the following advantages:

[0051] The present invention can monitor the material filling rate in the chain bucket in real time through a scanning and recognition method, calculate the real-time load of the lifting system in combination with the specific gravity parameters of the unloaded materials, and then adjust the material taking process strategy in a timely manner to stabilize the load and unloading flow of the lifting system.

[0052] The present invention realizes real-time material flow monitoring during the excavation process, eliminates the hysteresis of the traditional method of using lifting torque adjustment, and improves the system response speed and control accuracy.

[0053] The present invention dynamically adjusts the operating parameters of the ship unloader according to real-time flow data, thereby improving the operating efficiency and the flexibility of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0055] Figure 1 This is a schematic diagram of the installation position of the laser scanner of the present invention.

[0056] Figure 2 It is a framework diagram of the control system of the present invention.

[0057] Figure 3 The present invention displays the list data graph in a curve graph.

[0058] Figure 4 This is a GUI interface diagram for improving the bucket material volume of a segment chain according to the present invention.

[0059] Figure 5 This is a flow chart of the material flow control method of the present invention. DETAILED DESCRIPTION

[0060] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0061] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0062] The present invention provides a method for stabilizing material flow of a continuous ship unloader, comprising the following steps:

[0063] S1. Perform laser scanning on the material contours in each chain bucket that is continuously lifted to obtain material morphology point cloud data;

[0064] S2. Use statistical filtering method to denoise the material morphology point cloud data;

[0065] When the data enters the data processing module, the statistical filter determines whether the point is a noise point by calculating the number of neighboring points of each point. Assume that the point cloud data is P = {p1, p2, ..., p n}, where p i represents the coordinates of the i-th point. For each point p i , calculate the average distance of its k nearest neighbors:

[0066]

[0067] Among them, p i,j represents the jth neighbor point of the ith point, and ||·|| represents the Euclidean distance.

[0068] Compute the mean distance and standard deviation for all points:

[0069]

[0070] Set the threshold α to remove the average distance exceeding The points are regarded as noise points.

[0071] S3. Use the least square method to perform plane fitting on the denoised material morphology point cloud data to obtain the plane equation of the material surface;

[0072] In the plane fitting process of point cloud data, the least squares method is first used to solve the fitting plane equation ax+by+cz+d=0. Given a denoised point cloud data set Construct the design matrix A and observation vector p = [a, b, c] T :

[0073]

[0074] p=(A T A) -1 A T b

[0075] By singular value decomposition:

[0076] Finally, the plane equation is obtained:

[0077] S4, performing surface integration of the plane equation of the material surface and the chain bucket bottom equation obtained in advance to obtain the volume of the material;

[0078] Because each chain bucket has the same volume, the bottom surface of the empty chain bucket is scanned and entered into the server before the ship unloader is operated, forming the bottom surface equation z = z base .

[0079] According to the two plane equations obtained above, the volume of the material can be obtained by performing surface integral:

[0080]

[0081] A is the integration area, a ij are the fitting coefficients, n and m are the highest powers of the polynomial.

[0082] S5. Based on the standard volume of the chain bucket and the material volume, the filling rate of the material inside the chain bucket is obtained, the current material flow value is calculated according to the preset material specific gravity and the filling rate of the material inside the chain bucket, and the overall lifting load is obtained according to the current material flow value of each chain bucket;

[0083] According to the preset material specific gravity ρ, calculate the current material flow value Q:

[0084]

[0085] Where i is the number of chain buckets, L is the telescopic distance, and H is the distance from the root of the reclaiming head to the center of the sprocket. is the filling rate of the chain bucket.

[0086] Through an intuitive GUI interface, the material quantity changes in the chain bucket of the lifting section are displayed in real time. This interface will present the dynamic information of the material flow in a graphical way, so that the operator can clearly understand the changes in the material quantity at each stage. Figure 3 shown.

[0087] This display method is not only convenient for monitoring, but also effectively assists decision-making, ensuring that the system is always in the best condition during operation. In addition, this graphical display can quickly reflect any abnormal situation and provide data support for timely adjustment. Figure 4 The historical material flow curve shown can not only view the current data in real time, but also quickly count and analyze the data of the entire cycle.

[0088] S6. Compare the lifting material flow with the preset material flow value to determine the current material taking state, and adjust the material filling rate in the chain bucket according to the current material taking state to achieve dynamic control of the material taking flow. In the material flow control, the method of adjusting the chain bucket cross-cutting speed and digging depth can be comprehensively adopted. When the actual material flow Q act Greater than the preset material flow Q set When the actual material flow Q act Less than the preset material flow Q set When the chain bucket approaches the minimum safe distance d from the chain bucket to the bottom of the cabin, the cross-cutting speed can be increased first, and then the excavation depth can be increased. min When , only the crosscutting speed is allowed to be adjusted without changing the excavation depth. The control flow chart is as follows Figure 5 shown.

[0089] Use a database to store historical data. Include fields such as timestamp, bucket number, material quality, real-time material flow, etc., and use a database connection library to insert and query data. Regular backup and data management strategies ensure data security and reliability.

[0090] The present invention uses a laser scanner to identify the material filling rate in the chain bucket and monitor and control the material flow in the ship unloading operation in real time. The laser scanner is installed at the following position: Figure 1As shown, it is responsible for identifying the material filling status in the chain bucket; during the continuous ship unloader reclaiming operation, the chain bucket is continuously lifted, and the material filling status in the bucket during the lifting process of each chain bucket is identified by the laser scanner, and the point cloud data is transmitted to the server for processing. Point cloud data processing uses statistical filtering and least squares plane fitting technology. First, statistical filtering is used to eliminate noise points to improve data accuracy, and then the least squares method is used to fit the plane equation of the material surface. The material volume is obtained by performing surface integral on the fitted material surface equation and the pre-acquired chain bucket bottom surface equation. Based on the standard volume of the chain bucket and the calculated material volume, the filling rate of the material inside the chain bucket is finally determined. The chain bucket volume V 链斗 Is a constant.

[0091] Using the material specific gravity data entered before unloading, the formula Calculate the material load in the chain bucket currently scanned and identified. The number of chain buckets in the lifting stage of the continuous ship unloader can be identified according to the equipment structure drawing. In the overall lifting load calculation, a list data structure is used to store the excavation load of each chain bucket. The load storage quantity is the number of chain buckets in the lifting stage. The material load data set is moved in a container-like manner. After each chain bucket excavation, the material load is added to the end of the list while the data at the head of the list overflows, ensuring that the number of data in the data set is always constant, and then the total material load in the current data set is calculated through a real-time accumulation algorithm.

[0092] In the actual production of continuous ship unloaders, the unloading efficiency is obtained by increasing the load integral. By increasing the real-time value of the load, the current instantaneous unloading efficiency can be obtained, and by comparing the deviation between the instantaneous unloading efficiency and the target unloading efficiency, it can be determined whether the current material is underloaded or overloaded. Furthermore, by adjusting the chain bucket digging depth and cross-cutting speed, the material filling rate in the chain bucket can be adjusted to achieve dynamic and stable control of the material flow.

[0093] The present invention also provides a material flow stability control system for a continuous ship unloader, which uses a laser scanner to collect material data, calculates the filling rate and load after point cloud processing, and realizes real-time material flow control. It optimizes operating efficiency through dynamic adjustment and feedback, supports real-time data display, historical analysis and abnormal warning, and uses compression, backup and deep learning technologies to ensure data security and continuous optimization, including:

[0094] The laser scanning module is used to scan the material contours in each chain bucket to obtain the material shape point cloud data; the laser scanning module sends the material shape point cloud data to the data acquisition module; a laser scanner is installed at the step railing behind the material taking head to scan the material contours in the chain bucket. The position of the laser scanner ensures that the contour information of the material inside the chain bucket can be accurately obtained during the chain bucket lifting process.

[0095] The data acquisition module is used to collect the material morphology point cloud data of each chain bucket. In order to ensure the accuracy of the calculation results and the processing efficiency, the collected material morphology point cloud data is sent to the data processing module;

[0096] A data processing module is used to denoise the material shape point cloud data by a statistical filtering method, and perform plane fitting on the denoised material shape point cloud data to obtain the plane equation of the material surface; to perform surface integration on the plane equation of the material surface and the pre-acquired chain bucket bottom equation to obtain the material volume; to obtain the filling rate of the material inside the chain bucket based on the standard volume of the chain bucket and the material volume, calculate the current material flow value according to the preset material specific gravity and the filling rate of the material inside the chain bucket, and obtain the overall lifting load according to the current material flow value of each chain bucket;

[0097] The decision module is used to compare the overall lifting load with the preset material flow to obtain the current material reclaiming status, and adjust the material filling rate in the chain bucket through the digging module according to the current material reclaiming status

[0098] The GUI module is used to display the quality of materials dug by each bucket through a list data structure.

[0099] Excavation module: The material reclaiming head is controlled to run horizontally in the cabin through the linkage of horizontal movement, trolley, rotation of the material reclaiming head and linkage lifting mechanism, and the chain bucket is used to continuously excavate the materials and transport them to the dock belt.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling the material flow stability of a continuous ship unloader, characterized in that: The steps include: S1. Perform laser scanning on the material contours in each chain bucket that is continuously lifted to obtain material morphology point cloud data; S2. Use statistical filtering method to denoise the material morphology point cloud data; S3. Use the least square method to perform plane fitting on the denoised material morphology point cloud data to obtain the plane equation of the material surface; S4, performing surface integration of the plane equation of the material surface and the pre-obtained chain bucket bottom equation to obtain the material volume, and combining the material specific gravity to obtain the material load in the chain bucket; S5, storing the material load data in all chain buckets in the form of data stream, and accumulating the chain bucket load data in the current system in real time, and calculating the instantaneous material flow value of the system according to the current chain bucket lifting rate; S6. Compare the instantaneous material flow value with the preset target material flow value. If a difference is found, determine whether the current material taking state is underloaded or overloaded, automatically adjust the cross-cutting speed and excavation depth of the chain bucket according to the material taking state, and dynamically adjust the material filling rate of the subsequent chain bucket to achieve stable material taking flow control.

2. The method for controlling the material flow stability of a continuous ship unloader according to claim 1, characterized in that: S2 specifically includes the following steps: The statistical filtering method determines whether a point is a noise point by calculating the number of neighboring points of each point in the material morphology point cloud data. Assuming that the point cloud data is P = {p1, p2, ..., p n }, where p i Represents the coordinates of the i-th point. For each point p i , calculate the average distance of its k nearest neighbors: Among them, p i,j represents the jth neighbor point of the i-th point, and ||·|| represents the Euclidean distance; Compute the mean distance and standard deviation for all points: Set the threshold α, the average distance exceeds The points are regarded as noise points and the noise points are removed.

3. The method for controlling the material flow stability of a continuous ship unloader according to claim 1, characterized in that: S3 specifically includes the following steps: Solve the fitting plane equation ax+by+cz+d=0 by the least squares method; Given a denoised point cloud dataset Construct the design matrix A and observation vector p = [a, b, c] T : p=(A T A) -1 A T b Perform singular value decomposition on the design matrix A and the observation vector p: Get the plane equation of the material surface:

4. The method for controlling the material flow stability of a continuous ship unloader according to claim 1, characterized in that: S4 specifically includes the following steps: The pre-obtained chain bucket bottom equation is: z=z base ; Perform surface integral on the plane equation of the material surface and the chain bucket bottom equation: Among them, A is the integration area, a ij are the fitting coefficients, n and m are the highest powers of the polynomial.

5. The method for controlling the material flow stability of a continuous ship unloader according to claim 1, characterized in that: In S5: According to the preset material specific gravity ρ, calculate the current material flow value Q: Among them, i is the number of chain buckets, L is the telescopic distance, and H is the distance from the root of the reclaiming head to the center of the sprocket; is the filling rate of the chain bucket, 6. The method for controlling the material flow stability of a continuous ship unloader according to claim 1, characterized in that: In S5, in the calculation of the overall lifting load, a list data structure is used to store the excavation load of each chain bucket. The load storage quantity is the number of chain buckets in the lifting stage. The material load data set is moved in a container-like manner. After each chain bucket excavation, the material load is added to the end of the list while the data at the head of the list overflows, so that the number of data in the data set is always constant. The total material load in the current data set is calculated through a real-time accumulation algorithm.

7. The method for controlling the material flow stability of a continuous ship unloader according to claim 1, characterized in that: S6 specifically includes the following steps: When the actual material flow Q act Greater than the preset material flow Q set When the actual material flow Q act Less than the preset material flow Q set When the chain bucket approaches the minimum safe distance d from the chain bucket to the bottom of the cabin, first increase the excavation depth and then increase the crosscutting speed; min When adjusting, only the cross-cutting speed is adjusted without changing the digging depth.

8. A material flow stabilization control system for a continuous ship unloader, used to implement the material flow stabilization control method for a continuous ship unloader as claimed in any one of claims 1 to 7, characterized in that: include: The laser scanning module is used to scan the material contours in each chain bucket to obtain material shape point cloud data; The laser scanning module sends the material morphology point cloud data to the data acquisition module; A data acquisition module is used to collect the material shape point cloud data of each chain bucket and send the collected material shape point cloud data to the data processing module; A data processing module is used to denoise the material shape point cloud data by a statistical filtering method, and perform plane fitting on the denoised material shape point cloud data to obtain the plane equation of the material surface; to perform surface integration on the plane equation of the material surface and the pre-acquired chain bucket bottom equation to obtain the material volume; to obtain the filling rate of the material inside the chain bucket based on the standard volume of the chain bucket and the material volume, calculate the current material flow value according to the preset material specific gravity and the filling rate of the material inside the chain bucket, and obtain the overall lifting load according to the current material flow value of each chain bucket; The decision module is used to compare the overall lifting load with the preset material flow to obtain the current material taking state, and adjust the material filling rate in the chain bucket through the digging module according to the current material taking state; Excavation module: The material reclaiming head is controlled to run horizontally in the cabin through the linkage of horizontal movement, trolley, rotation of the material reclaiming head and linkage lifting mechanism, and the chain bucket is used to continuously excavate the materials and transport them to the dock belt.

9. The material flow stabilization control system for a continuous ship unloader according to claim 8, characterized in that: The laser scanning module includes a laser scanner installed at the step railing behind the material taking head.

10. The material flow stabilization control system of the continuous ship unloader according to claim 8, characterized in that: Also includes: The GUI module is used to display the quality of materials dug by each bucket through a list data structure.

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