Operation control method and system for portal frame type stacker-reclaimer of unmanned stockyard

Abstract

The invention relates to the technical field of control, in particular to a portal frame type stacker-reclaimer operation control method and system for an unmanned stockyard, and the method comprises the steps: obtaining the weight of a bucket wheel within a set working time; de-noising the obtained weight to obtain de-noised weight data, and sorting the de-noised weight data according to a time sequence to construct a weight sequence; calculating an autocorrelation function of the weight sequence, and determining a cycle period of bucket-wheel weight change; calculating a cycle index of the bucket wheel for completing the weight sequence corresponding to the cycle period; repeating the action that the bucket wheel completes the cycle period, and when the cycle index is smaller than a preset cycle index threshold value, controlling the bucket wheel to advance to the next position so as to improve the current feeding speed of the bucket wheel; otherwise, the current feeding speed of the bucket wheel is controlled to be kept unchanged. The bucket-wheel stacker-reclaimer can automatically adjust the operation position and depth to adapt to changes of material distribution and operation conditions, so that the operation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of control technology, and more specifically, to a method and system for controlling the operation of a gantry stacker-reclaimer in an unmanned material yard. Background Art

[0002] In unmanned material yards or automated bulk material yards, stackers with gantry structures are used to stack and unload materials. Among them, bucket wheel stackers are large-scale loading and unloading equipment used in bulk material storage and transportation systems with high efficiency and continuous operation. For the retrieving operation, the general steps include: the bucket wheel stacker first moves to the designated position of the material pile to ensure that the gantry is aligned with the material pile; the gantry descends to a position close to the surface of the material; the bucket wheel starts to rotate, and the bucket teeth on it are inserted into the material to dig up the material; lift the dug material; transport the material from the retrieving position to the unloading position; transport the material; after completing a retrieving cycle, the bucket wheel stacker may move to the next retrieving position and repeat the above process. With the development of technology, bucket wheel stackers are also constantly innovating in technology, including intelligent control, all-round environmental protection and green energy saving.

[0003] At present, the prior art, such as the patent application document with publication number CN114084585A, discloses a straight-moving material taking method and device for a bucket wheel stacker and reclaimer. The straight-moving material taking method for a bucket wheel stacker and reclaimer obtains the equipment operating parameters of the bucket wheel stacker and reclaimer, establishes a kinematic model of the bucket wheel stacker and reclaimer, generates a three-dimensional model of a target stockpile using point cloud data from a laser scanner, obtains the boundary position information of the target stockpile based on the kinematic model, sets straight-moving material taking parameters, including a starting position and an end position, etc., and obtains a straight-moving material taking task for the target stockpile based on a preset straight-moving material taking strategy and the boundary position information of the target stockpile.

[0004] The straight-moving material-retrieving method of the above-mentioned bucket wheel stacker and reclaimer solves the problem of large flow rate differences when retrieving materials in forward and backward directions. However, in the actual operation process, factors such as material weight and impact load have an impact on the bucket wheel and the entire mechanical structure, greatly reducing the operating efficiency of the stacker and reclaimer. Summary of the invention

[0005] In order to solve the above-mentioned technical problem of reducing the operating efficiency of the stacker-reclaimer, the present invention provides solutions in the following aspects.

[0006] In a first aspect, a method for controlling an operation of a gantry stacker-reclaimer in an unmanned material yard comprises: The weight of the bucket wheel within the set working time is obtained; the obtained weight is denoised to obtain denoised weight data, and the denoised weight data is sorted in chronological order to construct a weight sequence; Calculate the autocorrelation function of the weight sequence and determine the cycle period of bucket wheel weight change; Calculate the cycle index of the weight sequence corresponding to the bucket wheel completing the cycle period, and the cycle index is: ; In the formula, To complete the The cycle index of the weight sequence corresponding to the cycle period, For the The median of the weight sequence within a cycle period, For the The median of the weight sequence within a cycle; The bucket wheel repeats the action of completing a cycle. When the cycle index is less than the preset cycle index threshold, the bucket wheel is controlled to move to the next position to increase the current feeding speed of the bucket wheel; otherwise, the current feeding speed of the bucket wheel is controlled to remain unchanged.

[0007] By real-time monitoring of the load of the bucket wheel, obtaining the weight data of the bucket wheel within the set working time, denoising the weight data to ensure that the analyzed data is more accurate, further analyzing the weight data, calculating the cycle period and cycle index of the bucket wheel weight change, analyzing the bucket wheel's operating mode and efficiency, and automatically adjusting the bucket wheel's working speed and position based on the comparison between the cycle index and the preset threshold, reducing invalid operating time and improving the bucket wheel's operating efficiency.

[0008] Preferably, after the bucket wheel is controlled to move to the next position, the circulation index is calculated at the next position, and if the circulation index is less than the circulation index threshold, the bucket wheel is controlled to move downward until the bucket wheel descends to a height equal to the diameter of the bucket wheel.

[0009] When the circulation index is less than the preset threshold, the system will control the bucket wheel to descend until the bucket wheel descends to a height equal to its diameter, thus ensuring that the bucket wheel can maintain the optimal digging depth under different geological conditions.

[0010] Preferably, the denoising comprises: The obtained weights are clustered using the DBSCAN algorithm, multiple clusters and noise data are output, and the noise data is removed.

[0011] The DBSCAN algorithm can not only remove noise, but also identify outliers or outliers in the data; the DBSCAN algorithm is used to cluster the obtained weights without presetting the number of clusters.

[0012] Preferably, the product of the internal volume of the bucket wheel and the material density is used as the neighborhood radius in the DBSCAN algorithm.

[0013] The neighborhood radius of the DBSCAN algorithm is dynamically determined using the volume of the bucket wheel and the material density, and the parameters of the algorithm can be automatically adjusted according to different working conditions to adapt to different working environments.

[0014] Preferably, the denoising further comprises: The isolation coefficient of the clustered weight is calculated according to the output result of the DBSCAN algorithm. When the isolation coefficient is greater than the preset isolation coefficient threshold, the weight corresponding to the isolation coefficient is determined to be noise data.

[0015] The isolation coefficient is an indicator that measures whether the position of a data point in a cluster is isolated. By calculating the isolation coefficient, abnormal data points that are significantly different from other data points can be more accurately identified, thereby improving the recognition rate of noise data.

[0016] Preferably, the isolation coefficient is: ; In the formula, For the The isolation coefficient of the clustered weight corresponding to the moment, For the Time to The weight of all clusters between moments, is all the weights in the first cluster, For the All weights within the clusters.

[0017] Preferably, the denoising may also use an isolation forest or LOF algorithm.

[0018] In a second aspect, a gantry stacker-reclaimer operation control system for an unmanned material yard includes: a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the above-mentioned gantry stacker-reclaimer operation control method for the unmanned material yard is implemented.

[0019] The beneficial effects of the present invention are: The present invention allows the bucket wheel stacker and reclaimer to adaptively adjust the operating position and depth in response to changes in the distribution of materials and bucket wheel operating conditions. In this way, the bucket wheel stacker and reclaimer can maximize the amount of material excavated, reduce invalid or inefficient operating time, greatly improve the operating efficiency of the stacker and reclaimer, and ensure the effective use of resources. In addition, the automated control system can reduce the need for manual operation and improve the safety and accuracy of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 It is a method flow chart of steps S1 to S5 in a method for controlling operation of a gantry stacker-reclaimer in an unmanned material yard according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0022] The embodiment of the present invention discloses a gantry type stacker-reclaimer operation control method for an unmanned material yard, referring to Figure 1 , including steps S1 to S5, which are specifically as follows: S1: Get the weight of the bucket wheel within the set working time.

[0023] In the embodiment of the present invention, a high-precision weight sensor is installed on the bucket wheel, and the weight sensor is calibrated before starting to work. When the bucket wheel starts to work, the weight of the material carried by the bucket wheel during the working process is measured and recorded in real time. The working time is set to 60 minutes, and the frequency is set to collect weight once a minute.

[0024] S2: De-noise the acquired weight to obtain de-noised weight data, and sort the de-noised weight data in chronological order to construct a weight sequence.

[0025] In the process of bucket wheel stacker reclaimer taking materials, due to the unevenness of materials (such as gravels of different sizes), the bucket wheel will encounter heavy gravels when digging materials, which will cause the weight data of the bucket wheel to fluctuate. Therefore, it is necessary to denoise the weight obtained in the above step S1 to reduce the occurrence of data fluctuations and ensure the accuracy of the weight data.

[0026] In the embodiment of the present invention, the DBSCAN algorithm is selected to denoise the acquired weight.

[0027] DBSCAN (Density-Based Spatial Clustering of Applications with Noise) is a density-based clustering algorithm that can divide areas with sufficiently high density into clusters and can find clusters of any shape in the presence of noise. The DBSCAN algorithm is very suitable for denoising because it can identify and exclude outliers that do not belong to any cluster. In material operations, clustering can distinguish between normal operation data and abnormal noise data.

[0028] The general process of the above denoising is as follows: The neighborhood radius required by the DBSCAN algorithm is defined as b, and the minimum number of points is defined as a (the value of a is 10, and the value of the minimum number of points can also be adjusted based on historical data testing). The neighborhood radius is usually a fixed value, but the distribution of materials inside the bucket wheel may be uneven, which will affect the loading efficiency and equipment performance. Therefore, it is necessary to calculate the neighborhood radius to better understand the distribution of materials and optimize the loading process.

[0029] The weight of the material is an important factor to consider during loading. By calculating the product of the internal volume of the bucket wheel and the material density, the maximum material weight that a bucket can carry can be predicted. Therefore, the product of the internal volume of the bucket wheel (which is known) and the material density (which needs to be measured or estimated based on the actual material) is used as the neighborhood radius in the DBSCAN algorithm.

[0030] The weight, neighborhood radius and minimum number of points obtained in step S1 are input into the DBSCAN algorithm, and multiple clusters and noise data are output, where the noise data is the data points that do not belong to any cluster.

[0031] After obtaining the output of the DBSCAN algorithm, the isolation coefficient of the clustered weight data is further calculated based on the output of the DBSCAN algorithm. The isolation coefficient is an indicator that measures the similarity between a data point and other clusters. By calculating the isolation coefficient of each weight data after clustering, abnormal or noise data points that may be missed by the DBSCAN algorithm can be more flexibly identified.

[0032] Specifically, the weight of the first one that has not been assigned to any cluster after the clustering process is obtained, and the time point corresponding to the weight is recorded.

[0033] Then the isolation coefficient of each weight data after clustering satisfies the following relationship:

[0034] In the formula, For the The isolation coefficient of the clustered weight corresponding to the moment, For the Time to The weight of all clusters between moments, is all the weights in the first cluster, For the All weights within the clusters, is the time point corresponding to the first weight that has not been assigned to any cluster after the clustering process.

[0035] Then the isolation coefficient of all clustered weights is calculated, and then the isolation coefficient threshold is set. When the isolation coefficient is greater than the preset isolation coefficient threshold, the weight corresponding to the isolation coefficient is determined to be noise data, and the noise data is then removed.

[0036] The isolation coefficient threshold is set to 0.1. An initial threshold can also be set based on experience or domain knowledge, and then the value of the isolation coefficient threshold can be adjusted through experiments.

[0037] Furthermore, the weights after elimination are retained, and the eliminated positions are supplemented with mean values ​​and sorted in chronological order to construct a weight sequence.

[0038] In another embodiment, denoising may also use an isolation forest or LOF algorithm.

[0039] S3: Calculate the autocorrelation function of the weight sequence and determine the cycle period of the bucket wheel.

[0040] Since the bucket of a bucket wheel stacker reclaimer is periodically filled with materials and emptied during rotation, the weight of the bucket wheel changes periodically as the bucket wheel rotates.

[0041] The bucket wheel duty cycle is determined by analyzing the correlation of bucket wheel weight changes over time. This cycle can be used to evaluate bucket wheel efficiency and material supply. If the cycle matches the actual physical cycle of the bucket wheel, then it can be assumed that the bucket wheel is working properly and the material supply is sufficient. If the cycle becomes shorter or irregular, it may indicate a problem with the material supply and the bucket wheel needs to adjust its working position or strategy.

[0042] The autocorrelation function (ACF) can reflect the periodic characteristics of the signal at different time scales, and it is useful for identifying and analyzing periodic signals. In the application of bucket wheel stacker reclaimers, by calculating the autocorrelation function of the weight sequence, the periodic pattern of weight changes caused by the rotation of the bucket wheel can be captured. When the autocorrelation function shows significant peaks, the time delays corresponding to these peaks can be regarded as the cycle period of the data. Specifically, the peak of the autocorrelation function indicates that at a specific time delay, the weight data of the bucket wheel stacker reclaimer is most similar to itself, which usually means that the bucket wheel completes a complete rotation and material loading process within this cycle. By identifying these peaks, the cycle period of the bucket wheel can be determined, and the working status of the bucket wheel stacker reclaimer can be monitored and adjusted.

[0043] By calculating the correlation of bucket wheel weight changes over time, the cycle period of bucket wheel weight changes is determined.

[0044] Exemplarily, the correlation of bucket wheel weight with time satisfies the relationship:

[0045] In the formula, For the Moment and The correlation between the bucket wheel weight at the time, is a subsequence whose first item is The weight of time, is another subsequence whose first item is The weight of time, for and The covariance between them measures the strength of the linear relationship between the two new series. and They are and The variance measures the volatility of the sequence. is the cycle time to be measured, that is, the time interval between two weight measurements. The value of is less than or equal to the time it takes for the bucket wheel to rotate one circle.

[0046] Then traverse the cycle time to be tested , among all the calculated correlations Find the largest , corresponding to this maximum value The value is the cycle period of bucket wheel weight change, which means that the bucket wheel The time unit required to complete one cycle of weight change.

[0047] S4: Calculate the cycle index of the weight sequence corresponding to the bucket wheel completing the cycle period.

[0048] After determining the cycle period of bucket wheel weight change in the above step S3, the cycle index of the weight sequence corresponding to one cycle of the bucket wheel is calculated to satisfy the following expression:

[0049] In the formula, To complete the The cycle index of the weight sequence corresponding to the cycle period, For the The median of the weight sequence within a cycle period, For the The median of the weight sequence within a cycle period, is the Pearson correlation coefficient.

[0050] The index part Measured the median and If the difference between and If the index part is close to 1, it means that the weight series of the two periods are very similar in median value; conversely, if the index part is close to 0, it means that there is a large difference in median value between the two periods. If the two medians are highly correlated (i.e., the trend of change is consistent), then The value is close to 1 or -1; otherwise, it is close to 0.

[0051] S5: Repeat the action of the bucket wheel to complete a cycle. When the cycle index is less than the preset cycle index threshold, the bucket wheel is controlled to move to the next position to increase the current feeding speed of the bucket wheel; otherwise, the current feeding speed of the bucket wheel is controlled to remain unchanged.

[0052] The bucket wheel stacker reclaimer continuously executes the cycle period. At the end of each cycle period, the corresponding cycle index is calculated, and the cycle index threshold is set according to experience or experimental data.

[0053] If the circulation index is less than the preset circulation index threshold, it indicates that the material at the current working position may be insufficient or the excavation efficiency is not high. If the circulation index is greater than or equal to the preset circulation index threshold, it indicates that the material at the current working position is sufficient and the excavation efficiency is good.

[0054] When the circulation index is less than the circulation index threshold, it means that the working efficiency of the bucket wheel has decreased, and measures need to be taken to increase its feeding speed. At this time, the bucket wheel is controlled to move to the next position to change its working conditions or working area. Conversely, when the circulation index is greater than or equal to the circulation index threshold, it means that the working efficiency of the bucket wheel is normal, and its current feeding speed should be kept unchanged.

[0055] Furthermore, the circulation index can be recalculated at the new position, and if the circulation index calculated at the new position is still less than the threshold, the bucket wheel excavator is controlled to move downward, that is, the height of the bucket wheel is lowered. This descending process continues until the height of the bucket wheel is equal to the diameter of the bucket wheel, which ensures that the bucket wheel excavator can dig deeper to find more materials.

[0056] In another embodiment, a relationship model can be established to match the circulation index with the feeding speed of the bucket wheel, and then the feeding speed can be increased in a linear manner according to the circulation index. Linear adjustment means that the increase in feeding speed is proportional to the increase in circulation index, that is, for every increase in circulation index by one unit, the feeding speed also increases by a fixed proportion accordingly. In the process of adjusting the feeding speed, the change of circulation index is continuously monitored. If the circulation index is still less than the threshold, the feeding speed is continued to be increased; if the circulation index is greater than or equal to the threshold, the speed is stopped from being increased and the current speed is maintained.

[0057] For example, assume that the cycle index threshold is set to 0.7, the current cycle index is 0.5, and the ingestion speed is 10 units. If the data matching model shows that for every 0.1 increase in the cycle index, the ingestion speed needs to increase by 2 units, then when the cycle index is 0.6, the ingestion speed will be adjusted to 12 units. This process will continue until the cycle index reaches or exceeds 0.7, at which time the ingestion speed will remain unchanged.

[0058] The present invention allows the bucket wheel stacker and reclaimer to adaptively adjust the operating position and depth in response to changes in the distribution of materials and bucket wheel operating conditions. In this way, the bucket wheel stacker and reclaimer can maximize the amount of material excavated, reduce invalid or inefficient operating time, greatly improve the operating efficiency of the stacker and reclaimer, and ensure the effective use of resources. In addition, the automated control system can reduce the need for manual operation and improve the safety and accuracy of the operation.

[0059] An embodiment of the present invention further discloses a gantry stacker-reclaimer operation control system for an unmanned material yard, comprising a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, a gantry stacker-reclaimer operation control method for an unmanned material yard according to the present invention is implemented.

[0060] The system also includes other components familiar to those skilled in the art, such as a communication bus and a communication interface. The configuration and functions of these components are known in the art and will not be described in detail here.

[0061] In the present invention, the aforementioned memory may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, apparatus or device. For example, a computer-readable storage medium may be any appropriate magnetic storage medium or magneto-optical storage medium, such as a resistive random access memory RRAM (Resistive Random Access Memory), a dynamic random access memory DRAM (Dynamic Random Access Memory), a static random access memory SRAM (Static Random-Access Memory), an enhanced dynamic random access memory EDRAM (Enhanced Dynamic Random Access Memory), a high-bandwidth memory HBM (High-Bandwidth Memory), a hybrid memory cube HMC (Hybrid Memory Cube), etc., or any other medium that can be used to store the required information and can be accessed by an application, a module or both. Any such computer storage medium may be part of a device or accessible or connectable to a device.

[0062] In the description of this specification, "plurality" or "several" means at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0063] Although this specification has shown and described a number of embodiments of the present invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art will conceive of many modifications, changes and alternatives without departing from the ideas and spirit of the present invention. It should be understood that in the practice of the present invention, various alternatives to the embodiments of the present invention described herein may be employed.

Claims

1. A gantry stacker-reclaimer operation control method for an unmanned material yard, characterized in that: include: The weight of the bucket wheel within the set working time is obtained; the obtained weight is denoised to obtain denoised weight data, and the denoised weight data is sorted in chronological order to construct a weight sequence; Calculate the autocorrelation function of the weight sequence and determine the cycle period of bucket wheel weight change; Calculate the cycle index of the weight sequence corresponding to the bucket wheel completing the cycle period, and the cycle index is: ; In the formula, To complete the The cycle index of the weight sequence corresponding to the cycle period, For the The median of the weight sequence within a cycle period, For the The median of the weight sequence within a cycle; The bucket wheel repeats the action of completing the cycle. When the cycle index is less than the preset cycle index threshold, the bucket wheel is controlled to move to the next position to increase the current feeding speed of the bucket wheel; otherwise, the current feeding speed of the bucket wheel is controlled to remain unchanged.

2. The method for controlling the operation of a gantry stacker-reclaimer in an unmanned material yard according to claim 1, characterized in that: When the bucket wheel is controlled to move to the next position, the circulation index is calculated at the next position. If the circulation index is less than the circulation index threshold, the bucket wheel is controlled to move downward until the bucket wheel descends to a height equal to the diameter of the bucket wheel.

3. The method for controlling the operation of a gantry stacker-reclaimer in an unmanned material yard according to claim 2, characterized in that: The denoising comprises: The obtained weights are clustered using the DBSCAN algorithm, multiple clusters and noise data are output, and the noise data is removed.

4. The method for controlling the operation of a gantry stacker-reclaimer in an unmanned material yard according to claim 3, characterized in that: The product of the bucket wheel internal volume and the material density is used as the neighborhood radius in the DBSCAN algorithm.

5. The method for controlling the operation of a gantry stacker-reclaimer in an unmanned material yard according to claim 4, characterized in that: The denoising further comprises: The isolation coefficient of the clustered weight is calculated according to the output result of the DBSCAN algorithm. When the isolation coefficient is greater than the preset isolation coefficient threshold, the weight corresponding to the isolation coefficient is determined to be noise data.

6. The method for controlling the operation of a gantry stacker-reclaimer in an unmanned material yard according to claim 5, characterized in that: The isolation coefficient is: ; In the formula, For the The isolation coefficient of the clustered weight corresponding to the moment, For the Time to The weight of all clusters between moments, is all the weights in the first cluster, For the All weights within the clusters.

7. The method for controlling the operation of a gantry stacker-reclaimer in an unmanned material yard according to claim 1, characterized in that: The denoising may also use an isolation forest or LOF algorithm.

8. A gantry stacker-reclaimer operation control system for an unmanned material yard, characterized in that: include: A processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the gantry stacker-reclaimer operation control method for an unmanned material yard according to any one of claims 1 to 7 is implemented.

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