Crown block path dynamic planning method and device, electronic equipment and storage medium

Abstract

The invention provides a crown block path dynamic planning method and device, electronic equipment and a storage medium, and the method comprises the steps: executing a dynamic path planning step based on a current track section of a target crown block, a track map and a local path length in a path updating step, and obtaining a current optimal path; in the crown block control step, a target crown block is controlled to advance along the current optimal path until the number of track sections through which the target crown block passes is equal to the local path length, a path updating condition is determined to be met, and the path updating step is skipped to. Wherein in the dynamic path planning step, local path planning is carried out based on a current track section of a target crown block and a track map to obtain a plurality of local paths of which the lengths are equal to those of the local paths, and a current optimal path is selected based on each local path and the transportation time from the last track section to a terminal track section; the rolling optimization strategy based on the fixed local path length improves the efficiency and flexibility of the crown block path planning method.

Description

Technical Field

[0001] The present invention relates to the technical field of path planning, and in particular, to an overhead hoist transport (OHT) path dynamic planning method, apparatus, electronic device, and storage medium. Background Art

[0002] Currently, modern semiconductor manufacturing equipment in a wafer fab usually uses an Automatic Material Handling System (AMHS) to handle the transportation of wafers. Among them, the AMHS usually uses an overhead hoist transport (OHT) to transport wafers along a track network deployed on the factory ceiling. To ensure the efficiency of the process flow, it is crucial to plan the shortest route for the OHT responsible for transporting wafers. Currently, most path planning algorithms for OHTs use static planning algorithms, such as the Dijkstra algorithm and the A-Star algorithm.

[0003] However, in a dynamic production environment, the state of the track network, the position of the OHT, and the state of the machines in the wafer fab are constantly changing. Since the traffic conditions directly affect the travel time of the track segment, when the OHT moves towards the destination node, the actual travel time of the route will change dynamically, resulting in problems such as static planning strategies being difficult to adapt to dynamic traffic flow or unexpected emergencies. Further, dynamic planning algorithms can adapt to changing traffic conditions. However, when performing real-time path planning, the search space of the dynamic planning algorithm is all possible paths from the current node to the destination node (i.e., the end point of the OHT handling task), and this search space is large, resulting in high computational complexity. In addition, since dynamic path planning strategies require a large amount of computing resources, traditional dynamic planning algorithms usually rely on heuristic functions. Unfortunately, the performance of dynamic planning algorithms that rely on heuristic functions depends on the quality of the heuristic function. However, in the case of constantly changing traffic conditions, a fixed heuristic function may be difficult to meet the requirements of different scenarios. If the heuristic function is updated in real time to adapt to the changes, it may lead to an increase in computational complexity, affecting the real-time performance and response speed of the algorithm. Therefore, to meet the wafer handling requirements of modern wafer fabs, an OHT path planning algorithm that can adapt to changing traffic conditions and maintain high efficiency needs to be designed. Summary of the Invention

[0004] The present invention provides an OHT path dynamic planning method, apparatus, electronic device, and storage medium to solve the defects of high path planning complexity and poor real-time performance in the prior art.

[0005] The present invention provides an OHT path dynamic planning method, including: Path update step: During the process of the target crane performing the handling task, if the path update condition is met, perform a dynamic path planning step based on the current track section where the target crane is located, the track map, and the local path length to obtain the current optimal path; Crane control step: Control the target crane to travel along the current optimal path until the number of track sections passed by the target crane is equal to the local path length, determine that the path update condition is met, and jump to the path update step; Among them, the dynamic path planning step includes: Perform local path planning based on the current track section where the target crane is located and the track map to obtain multiple local paths with lengths equal to the local path length; Predict the transportation time from the last track section of the local path to the end track section of the target crane; Based on each local path and the transportation time from its last track section to the end track section, select the current optimal path.

[0006] According to a crane path dynamic planning method provided by the present invention, the performing local path planning based on the current track section where the target crane is located and the track map to obtain multiple local paths with lengths equal to the local path length includes: Set the time parameter of the current track section to 0, set the time parameters of other track sections to preset values, and construct a path containing only the current track section and add it to the local path set; When the length of any path in the local path set is less than the local path length, perform a local path search step; The local search step includes: Obtain the any path and delete the any path from the local path set; Based on the passing time from the last track section of the any path to its respective adjacent track sections, the time parameter of the last track section, and the time parameters of the respective adjacent track sections, expand the any path to obtain several expanded paths, and add the expanded paths to the local path set; the length of the expanded path is 1 greater than the length of the any path.

[0007] According to a crane path dynamic planning method provided by the present invention, the passing time from any track section to any adjacent track section is determined based on the normal passing time from the any track section to the any adjacent track section without congestion and a congestion penalty coefficient; the longer the average historical passing time from the any track section to the any adjacent track section, the greater the congestion penalty coefficient.

[0008] A method for dynamic planning of the path of an overhead crane provided by the present invention, predicting the transportation time from the last track segment of the local path to the end track segment of the target overhead crane, includes: Obtain the graph feature vectors of the subgraph with the last track segment of the local path as the root node and the subgraph with the end track segment as the root node in the track map; Based on the graph feature vectors corresponding to the last track segment of the local path and the end track segment, the current number of overhead cranes on each track segment in the track map, and the load feature vectors of each processing device, predict the transportation time from the last track segment of the local path to the end track segment of the target overhead crane; the load feature vector of the processing device includes the number of handling tasks with the processing device as the handling starting point and the number of handling tasks with the processing device as the handling ending point.

[0009] A method for dynamic planning of the path of an overhead crane provided by the present invention, controlling the target overhead crane to travel along the current optimal path until the number of track segments passed by the target overhead crane is equal to the length of the local path, further includes: During the process of controlling the target overhead crane to travel along the current optimal path, determine the observed track segment in the current optimal path based on the length of the local path, and update the length of the local path based on the congestion information of each track segment in the first track network subgraph corresponding to the observed track segment at each time period; Wherein, the first track network subgraph corresponding to the observed track segment is the largest subgraph in the track map with the observed track segment as the root node; The updated length of the local path satisfies any of the following conditions: In the second track network subgraph obtained from the first track network subgraph corresponding to the observed track segment with the observed track segment as the starting point and the updated length of the local path as the maximum number of hops, the congestion change rates of more than a preset number of track segments are less than a preset threshold, and the updated length of the local path is less than or equal to a preset maximum value; The updated length of the local path is equal to a preset minimum value.

[0010] A method for dynamic planning of the path of an overhead crane provided by the present invention, selecting the current optimal path based on each local path and the transportation time from its last track segment to the end track segment, includes: Calculate the transportation time of each local path; Based on the transportation time of each local path, the transportation time from the last track segment of each local path to the end track segment, and the current adjustment coefficient, determine the global transportation time corresponding to each local path; wherein, the higher the congestion degree of the current track network, the larger the current adjustment coefficient.

[0011] The present invention also provides a dynamic path planning device for an overhead crane, including: A path update unit, configured to perform dynamic path planning steps based on the current track section where the target overhead crane is located, the track map, and the local path length if the path update condition is satisfied during the process of the target overhead crane performing the handling task, so as to obtain the current optimal path; An overhead crane control unit, configured to control the target overhead crane to travel along the current optimal path until the number of track sections passed by the target overhead crane is equal to the local path length, determine that the path update condition is satisfied, and call the path update unit; Wherein, the dynamic path planning steps include: Performing local path planning based on the current track section where the target overhead crane is located and the track map to obtain multiple local paths with a length equal to the local path length; Predicting the transportation time from the last track section of the local path to the end track section of the target overhead crane; Selecting the current optimal path based on each local path and the transportation time from its last track section to the end track section.

[0012] According to the dynamic path planning device for an overhead crane provided by the present invention, the controlling the target overhead crane to travel along the current optimal path until the number of track sections passed by the target overhead crane is equal to the local path length further includes: During the process of controlling the target overhead crane to travel along the current optimal path, determining the observed track section in the current optimal path based on the local path length, and updating the local path length based on the congestion information of each track section in the first track network subgraph corresponding to the observed track section at each time period; Wherein, the first track network subgraph corresponding to the observed track section is the largest subgraph in the track map with the observed track section as the root node; The updated local path length satisfies any of the following conditions: In the second track network subgraph obtained from the first track network subgraph corresponding to the observed track section with the observed track section as the starting point and the updated local path length as the maximum number of hops, the congestion change rate of more than a preset number of track sections is less than a preset threshold, and the updated local path length is less than or equal to a preset maximum value; The updated local path length is equal to a preset minimum value.

[0013] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor implements the overhead crane path dynamic planning method as described in any one of the above when executing the program.

[0014] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the overhead crane path dynamic planning method described in any one of the above is implemented.

[0015] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, the overhead crane path dynamic planning method described in any one of the above is implemented.

[0016] The overhead crane path dynamic planning method, device, electronic device and storage medium provided by the present invention, in the path update step, if the path update condition is satisfied, then based on the current track section where the target overhead crane is located, the track map and the local path length, execute the dynamic path planning step to obtain the current optimal path; in the overhead crane control step, control the target overhead crane to travel along the current optimal path until the number of track sections passed by the target overhead crane is equal to the local path length, determine that the path update condition is satisfied and jump to the path update step, wherein in the dynamic path planning step, local path planning is performed based on the current track section where the target overhead crane is located and the track map to obtain multiple local paths with a length equal to the local path length, predict the transportation time from the last track section of the local path to the end track section of the target overhead crane, and based on each local path and its transportation time from the last track section to the end track section, select the current optimal path. The rolling optimization strategy based on a fixed local path length improves the efficiency and flexibility of the overhead crane path planning method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 is a flowchart of the overhead crane path dynamic planning method provided by the present invention; Figure 2 is a flowchart of the dynamic path planning step provided by the present invention; Figure 3 is a structural diagram of the overhead crane path dynamic planning device provided by the present invention; Figure 4 is a structural diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0020] Figure 1 is a schematic flowchart of the overhead crane path dynamic planning method provided by the present invention. As Figure 1 shown, the method includes: Path update step 110: During the process of the target overhead crane executing the handling task, if the path update condition is satisfied, perform the dynamic path planning step based on the current track section where the target overhead crane is located, the track map, and the local path length to obtain the current optimal path; Overhead crane control step 120: Control the target overhead crane to travel along the current optimal path until the number of track sections passed by the target overhead crane is equal to the local path length, determine that the path update condition is satisfied, and jump to the path update step; Among them, as Figure 2 shown, the dynamic path planning step includes: Step 210, perform local path planning based on the current track section where the target overhead crane is located and the track map to obtain multiple local paths with a length equal to the local path length; Step 220, predict the transportation time from the last track section of the local path to the end track section of the target overhead crane; Step 230, select the current optimal path based on each local path and the transportation time from its last track section to the end track section.

[0021] Here, in a dynamic production environment, the status of the track network, the position of the OHT, and the status of the fab machines are constantly changing. Since the traffic conditions directly affect the travel time of the track segments, the actual travel time of the route will change dynamically when the OHT moves towards the destination node. The traditional static global path planning method can no longer meet the requirements of real-time and flexibility. When the current dynamic programming algorithm performs real-time path planning, the search space is all possible paths from the current node to the target node, resulting in a large computational complexity. In addition, the traditional dynamic programming algorithm usually relies on a heuristic function. However, in the case of constantly changing traffic conditions, a fixed heuristic function may be difficult to meet the requirements in different scenarios, and real-time updating of the heuristic function may lead to an increase in computational complexity, affecting the real-time performance and response speed of the algorithm. To address the above problems, the embodiments of the present invention propose a dynamic path planning method for the OHT that combines local path planning and a dynamic update mechanism to improve the overall transportation efficiency of the system.

[0022] Specifically, at the beginning of the task, a static path planning algorithm can be used to perform preliminary path planning based on the track segment where the target OHT is currently located, the complete track map (representing the spatial position relationship of each track segment in the track network), and the end point of the handling task, to obtain an initial path, and control the target OHT to start performing the handling task along this initial path. During the process of the OHT traveling along the planned path to perform the handling task, the driving state of the target OHT is monitored in real time. When it is detected that the driving state of the target OHT meets the path update condition, for example, the OHT has traveled a local path of a preset length (i.e., the local path length described later), the path update operation is immediately triggered. After triggering the path update operation, the system will perform dynamic programming steps based on the track segment where the target OHT is currently located, the track map, and the local path length to obtain the current optimal path.

[0023] Among them, in the dynamic path planning step, the system searches for all local paths with a length equal to the local path length based on the current track section where the target crane is located and the track map information. Here, a local path refers to a feasible path that starts from the current track section where the target crane is located and passes through several track sections (the number is equal to the local path length). Then, the transportation time from the end track section of each local path to the end track section of the target crane's handling task is predicted. For each local path, based on the cumulative transportation time of the current local path (i.e., the transportation time required from the start point to the end point of the local path) and the transportation time from its end track section to the end track section, the global transportation time is determined as the comprehensive evaluation index, and the local path with the shortest global transportation time is selected as the new current optimal path. Here, the global transportation time corresponding to each local path can be determined based on the cumulative transportation time of each local path, the transportation time from the last track section of each local path to the end track section, and the current adjustment coefficient. Among them, the higher the congestion degree of the current track network, the greater the current adjustment coefficient. For example, the global transportation time corresponding to any local path can be calculated based on the following formula: T all = T + β × T remain Here, T all is the global transportation time corresponding to any local path, T is the transportation time of this local path, and T remain is the transportation time from the last track section of this local path to the end track section, and β is the current adjustment coefficient.

[0024] In some embodiments, local path planning can be performed based on the following steps: Set the time parameter of the current track section to 0, and set the time parameters of other track sections to a preset value (a very large value). Among them, the time parameter of any track section represents the passing time required from the current track section where the target crane is located to this track section. Then, a path containing only the current track section is constructed and added to the local path set. At this time, there is only this one path in the local path set; when the length of any path in the local path set is less than the local path length, perform the local path search step for this path.

[0025] Among them, the local search step includes: obtaining this path and deleting this path from the set of local paths; then, based on the travel time from the last track segment of this path to each of its adjacent track segments, the time parameter of the last track segment, and the time parameters of each adjacent track segment, expanding this path to obtain several expanded paths, and adding the expanded paths to the set of local paths. Here, the length of the expanded path is 1 greater than the length of this path. Specifically, when expanding the path, if the sum of the travel time from the last track segment of this path to any of its adjacent track segments and the time parameter of the last track segment (assumed to be d) is less than the time parameter of this adjacent track segment, then add this adjacent track segment to the end of this path to obtain an expanded path, and at the same time update the time parameter of this adjacent track segment to the above d value.

[0026] In some embodiments, the travel time from any track segment to any of its adjacent track segments is determined based on the normal travel time from this track segment to the above adjacent track segment under non-congested conditions and the congestion penalty coefficient. Among them, the longer the average historical travel time from this track segment to the above adjacent track segment, the greater the congestion penalty coefficient. For example, the travel time from any track segment to any of its adjacent track segments can be calculated based on the following formula: dist_btw(u,v)=edge(u,v)×(1+CongestionPenalty(u,v)) Where u is any of the above track segments, v is any of the above adjacent track segments, dist_btw(u,v) is the travel time from any of the above track segments to any of the above adjacent track segments, edge(u,v) is the normal travel time from this track segment to the above adjacent track segment under non-congested conditions, and CongestionPenalty is the congestion penalty coefficient.

[0027] In some other embodiments, the transportation time from the last track segment of any local path to the end track segment of the target crane can be predicted based on the following method: (1) Based on the track map, respectively use the last track segment of the local path and the end track segment as the root nodes to extract the corresponding subgraph structures. The subgraph can include the set of track segments within several hops outward along the track network starting from the root node to effectively capture the topological information and traffic conditions of the current track segment and its surrounding areas. Subsequently, based on the above subgraph structures, extract the graph feature vectors of each subgraph. The graph feature vectors can include but are not limited to: the connection relationships between track segments, the basic attributes of each track segment (such as length, allowed speed, historical traffic flow), the congestion levels of adjacent track segments, node centrality, etc., comprehensive information, so as to form a high-dimensional feature expression that can comprehensively reflect the local track state.

[0028] After obtaining the graph feature vectors of the end segment of the local path and the end-point track segment, the system further collects the current number of overhead cranes for each track segment in the track map. As an important indicator of dynamic traffic load, the number of overhead cranes can effectively reflect the traffic pressure and potential delay risk of each track segment. In addition, the system also synchronously collects the load feature vectors of each processing device, which include the number of handling tasks starting from the processing device and the number of handling tasks ending at the processing device. As the source or destination of the overhead crane handling tasks, the load condition of the processing device directly affects the queuing time and the waiting time for departure after the overhead crane arrives, so it is an important factor that cannot be ignored.

[0029] After integrating the above information, the system uses a regression prediction model based on deep learning, such as a multi-layer perceptron (MLP), a graph neural network (GNN), or other lightweight prediction networks, taking the graph feature vectors of the end segment of the local path, the graph feature vectors of the end-point track segment, the number of overhead cranes for each track segment, and the load feature vectors of the processing devices as input features. After feature fusion and deep reasoning, it outputs the predicted transportation time.

[0030] Through the method of the above embodiments, the system can accurately predict the estimated transportation time from the last track segment of the local path to the target end-point track segment in real time during the dynamic path planning process. Furthermore, in the local path selection stage, based on the principle of the shortest overall transportation time, it can reasonably select the current optimal path. Compared with the traditional prediction methods that only rely on the static characteristics of the track segments or the current distribution of the overhead cranes, this embodiment fully integrates the local track topology features, the traffic flow state, and the load factors of the processing devices, can more comprehensively reflect the changes in the real transportation environment, and greatly improves the accuracy of the path selection decision and the overall handling efficiency of the system.

[0031] After the path update is completed, the system will control the overhead crane to continue moving along the new current optimal path until it reaches the task end point or meets the path update condition again (the number of track segments passed by the target overhead crane is equal to the length of the local path). It should be noted that when the path update condition is met, if the number of track segments passed from the track segment where the target overhead crane is currently located to the end-point track segment is less than or equal to the above local path length, any path planning algorithm can be directly called to perform path planning based on the current track segment and the end-point track segment to obtain a current optimal path pointing to the end-point track segment.

[0032] It can be seen that through this local path segmentation control and dynamic adjustment mechanism, the overhead crane can maintain a high transportation efficiency and task completion rate in a dynamically changing rail transit environment. Traditional dynamic path planning algorithms perform a large-scale path search on the global path (i.e., all paths from the current position to the end point), with high computational complexity. In scenarios where the scale of the rail network is huge, it is easy to cause obvious path update delays, which greatly affects the overall transportation efficiency and real-time performance of the system. In contrast, the dynamic local path planning and control solution proposed in the embodiments of the present invention adopts a rolling optimization strategy based on a fixed local path length. Specifically, the system does not directly search for the complete path from the starting point to the end point, but plans a locally limited-length path in the rail map according to the current position of the target overhead crane, and dynamically determines whether to update the path during the process of the overhead crane moving along the local path. This method effectively decomposes the path planning problem into a series of small-scale and continuous local optimization problems, thus greatly reducing the computational complexity of single-path calculation. Since only a fixed number of rail segments need to be planned each time, the solution of the present invention can make local adjustments at extremely high speed when facing real-time changes in rail transit conditions (such as rail congestion, temporary failures, traffic control, etc.), avoiding the computational bottleneck caused by global dependence in traditional dynamic path planning methods. In addition, by predicting the remaining transportation time at the end of each local path and using it as a selection basis, not only the local path is optimized, but also the overall transportation process is ensured to continuously advance in the globally optimal direction towards the end point, thus taking into account the consistency between local optimality and global goals.

[0033] The setting of the local path length has an important impact on the above dynamic path planning method. Specifically, the value of the local path length should not be too large. If the local path length is set too long, the number of rail segments involved in each local path planning increases, resulting in a significant increase in the computational complexity of local path search. In addition, a longer local path length also makes the overhead crane lack sufficient adjustment opportunities during execution. If rail transit conditions change (such as local congestion, temporary failures, etc.), it is difficult to update and optimize the path in a timely manner, reducing the flexibility of the system and its adaptability to dynamic changes. On the other hand, the value of the local path length should not be too small. If the local path length is set too short, the overhead crane needs to re-plan the path at a high frequency during the handling process. Although the single-path search range is small, due to the increase in path update frequency, the cumulative path planning overhead also increases, instead resulting in an increase in the overall computational complexity, an increase in system resource occupancy, and an impact on handling efficiency and response speed. Therefore, in some embodiments, the local path length can be reasonably determined according to the traffic condition changes of each rail segment in the rail network to achieve a good balance between path search overhead and system flexibility.

[0034] Specifically, during the process of the target overhead crane traveling along the current optimal path (i.e., before the next path update step is triggered), the observed track segment in the current optimal path is determined based on the current local path length. The observed track segment refers to the k-th track segment starting from the starting point in the current optimal path, where k is the current local path length. This observed track segment will be used as a reference for updating the local path length. Subsequently, based on the congestion change information of each track segment in the first track network subgraph corresponding to the observed track segment, the local path length is updated. Specifically, the first track network subgraph corresponding to the observed track segment is the largest subgraph (the subgraph with the deepest depth) extracted from the track map with this observed track segment as the root node. This subgraph covers all track segments and connection relationships in the track map that start from the observed track segment and can be reached within a certain number of hops, and can reflect the congestion situation in the local area near the observed track segment. The system monitors and collects the congestion information of the track segments in the first track network subgraph in real time. This congestion information includes, but is not limited to: the number of overhead cranes on each track segment in each time period, the average passing time of each time period, etc. Based on this congestion information, the system can judge the congestion trend of each track segment and calculate the congestion change rate of each track segment. The congestion change rate refers to the degree of change in the traffic flow of the track segment within a certain time period, and can be obtained based on the variance of the congestion information of the corresponding track segment in each time period. Based on the congestion information of each track segment in the first track network subgraph collected at each time, the system will dynamically adjust the local path length required for the next path update.

[0035] Specifically, the updated local path length satisfies the following conditions: taking the observed track segment as the starting point and the updated local path length as the maximum number of hops, in the second track network subgraph obtained from the first track network subgraph corresponding to the observed track segment, the congestion change rates of more than a preset number of track segments are less than a preset threshold, and the updated local path length is less than or equal to a preset maximum value. In this way, the system can flexibly adjust the path length according to the predicted traffic flow to avoid unnecessary congestion caused by an overly long path or frequent path updates caused by an overly short path.

[0036] Alternatively, the updated local path length is equal to the preset minimum value.

[0037] In some embodiments, the local path length can be updated in the following manner: Starting from the observation orbit segment, move k (the initial value of k is 1) jumps along the edges in the first orbital network subgraph corresponding to the observation orbit segment. If there are more than a preset number of orbit segments with congestion change rates less than a preset threshold among the passed orbit segments and the current value of k is less than the preset maximum value, then increase k by 1 and repeat the above operation; if the number of orbit segments with congestion change rates less than the preset threshold among the passed orbit segments is less than the preset number or the current value of k is equal to the preset maximum value, then determine the larger value between the current value of k and the preset minimum value as the updated local path length.

[0038] Once the local path length is updated, when the system triggers the path update operation next time, it will perform the dynamic path planning step based on the new local path length. Through the local path length update method of this embodiment, the system can dynamically adjust the local path length of the target crane, so as to ensure that when the congestion condition of the orbital network changes, it can quickly respond to the change of the orbital condition, avoid the efficiency loss or congestion problem caused by too long or too short local path, and thus significantly improve the overall efficiency of the crane handling operation.

[0039] In summary, the method provided by the embodiment of the present invention, in the path update step, if the path update condition is met, then perform the dynamic path planning step based on the current orbit segment where the target crane is located, the orbit map, and the local path length to obtain the current optimal path; in the crane control step, control the target crane to travel along the current optimal path until the number of orbit segments passed by the target crane is equal to the local path length, determine that the path update condition is met and jump to the path update step, where in the dynamic path planning step, local path planning is performed based on the current orbit segment where the target crane is located and the orbit map to obtain multiple local paths with lengths equal to the local path length, predict the transportation time from the last orbit segment of the local path to the end orbit segment of the target crane, and based on each local path and its transportation time from the last orbit segment to the end orbit segment, select the current optimal path, and improve the efficiency and flexibility of the crane path planning method based on the rolling optimization strategy with a fixed local path length.

[0040] Next, the crane path dynamic planning device provided by the present invention will be described. The crane path dynamic planning device described below can be mutually corresponding and referred to with the crane path dynamic planning method described above.

[0041] Based on any of the above embodiments, Figure 3 is a schematic structural diagram of the crane path dynamic planning device provided by the present invention, as Figure 3 shown, the device includes: A path update unit 310, configured to, during the process of the target overhead crane performing a handling task, if a path update condition is satisfied, perform a dynamic path planning step based on the current track section where the target overhead crane is located, a track map, and a local path length, to obtain a current optimal path; An overhead crane control unit 320, configured to control the target overhead crane to travel along the current optimal path until the number of track sections passed by the target overhead crane is equal to the local path length, determine that the path update condition is satisfied, and call the path update unit; Wherein, the dynamic path planning step includes: Performing local path planning based on the current track section where the target overhead crane is located and the track map, to obtain a plurality of local paths with a length equal to the local path length; Predicting the transportation time from the last track section of the local path to the end track section of the target overhead crane; Based on each local path and the transportation time from its last track section to the end track section, selecting the current optimal path.

[0042] The device provided by the embodiment of the present invention, in the path update step, if a path update condition is satisfied, performs a dynamic path planning step based on the current track section where the target overhead crane is located, a track map, and a local path length, to obtain a current optimal path; in the overhead crane control step, controls the target overhead crane to travel along the current optimal path until the number of track sections passed by the target overhead crane is equal to the local path length, determines that the path update condition is satisfied, and jumps to the path update step, wherein in the dynamic path planning step, local path planning is performed based on the current track section where the target overhead crane is located and the track map, to obtain a plurality of local paths with a length equal to the local path length, predicts the transportation time from the last track section of the local path to the end track section of the target overhead crane, and based on each local path and the transportation time from its last track section to the end track section, selects the current optimal path, improving the efficiency and flexibility of the overhead crane path planning method based on a rolling optimization strategy with a fixed local path length.

[0043] Based on any of the above embodiments, the performing local path planning based on the current track section where the target overhead crane is located and the track map, to obtain a plurality of local paths with a length equal to the local path length, includes: Setting the time parameter of the current track section to 0, setting the time parameters of other track sections to a preset value, and constructing a path that only includes the current track section and adding it to the local path set; When the length of any path in the local path set is less than the local path length, performing a local path search step; The local search step includes: Obtain any one of the paths and delete the any one of the paths from the set of local paths; Based on the travel time from the last track segment of the any one of the paths to each of its adjacent track segments, the time parameter of the last track segment, and the time parameters of the respective adjacent track segments, expand the any one of the paths to obtain a plurality of expanded paths, and add the expanded paths to the set of local paths; the length of the expanded paths is 1 greater than the length of the any one of the paths.

[0044] Based on any one of the above embodiments, the travel time from any one track segment to any one of its adjacent track segments is determined based on the normal travel time from the any one track segment to any one of its adjacent track segments under non-congested conditions and a congestion penalty coefficient; the longer the average historical travel time from the any one track segment to any one of its adjacent track segments, the greater the congestion penalty coefficient.

[0045] Based on any one of the above embodiments, predicting the transportation time from the last track segment of the local path to the end track segment of the target crane includes: Obtain the graph feature vectors of the subgraph with the last track segment of the local path as the root node and the subgraph with the end track segment as the root node in the track map; Based on the graph feature vectors corresponding to the last track segment of the local path and the end track segment, the current number of cranes on each track segment in the track map, and the load feature vectors of each processing device, predict the transportation time from the last track segment of the local path to the end track segment of the target crane; the load feature vector of the processing device includes the number of handling tasks with the processing device as the handling starting point and the number of handling tasks with the processing device as the handling end point.

[0046] Based on any one of the above embodiments, controlling the target crane to travel along the current optimal path until the number of track segments passed by the target crane is equal to the length of the local path further includes: During the process of controlling the target crane to travel along the current optimal path, determine the observed track segment in the current optimal path based on the length of the local path, and update the length of the local path based on the congestion information of each track segment in the first track network subgraph corresponding to the observed track segment at each time period; Wherein, the first track network subgraph corresponding to the observed track segment is the largest subgraph in the track map with the observed track segment as the root node; The updated local path length satisfies any one of the following conditions: Taking the observation orbit segment as the starting point and the updated local path length as the maximum number of hops, in the second orbit network subgraph obtained from the first orbit network subgraph corresponding to the observation orbit segment, the congestion change rate of more than a preset number of orbit segments is less than a preset threshold, and the updated local path length is less than or equal to a preset maximum value; The updated local path length is equal to the preset minimum value.

[0047] Based on any of the above embodiments, the selecting the current optimal path based on the transportation times of each local path and its last orbit segment to the end orbit segment includes: Calculating the transportation time of each local path; Based on the transportation times of each local path, the transportation times of the last orbit segment of each local path to the end orbit segment, and the current adjustment coefficient, determining the global transportation time corresponding to each local path; wherein, the higher the congestion degree of the current orbit network, the larger the current adjustment coefficient.

[0048] Figure 4 is a schematic structural diagram of an electronic device provided by the present invention. As Figure 4 shown, the electronic device may include: a processor 410, a memory 420, a communication interface 430, and a communication bus 440. Among them, the processor 410, the memory 420, and the communication interface 430 complete communication with each other through the communication bus 440. The processor 410 may call the logical instructions in the memory 420 to execute the overhead crane path dynamic planning method, and the method includes: a path update step: during the process of the target overhead crane executing the handling task, if the path update condition is satisfied, based on the current orbit segment where the target overhead crane is located, the orbit map, and the local path length, performing a dynamic path planning step to obtain the current optimal path; an overhead crane control step: controlling the target overhead crane to travel along the current optimal path until the number of orbit segments passed by the target overhead crane is equal to the local path length, determining that the path update condition is satisfied and jumping to the path update step; wherein, the dynamic path planning step includes: performing local path planning based on the current orbit segment where the target overhead crane is located and the orbit map to obtain a plurality of local paths with lengths equal to the local path length; predicting the transportation time of the last orbit segment of the local path to the end orbit segment of the target overhead crane; and selecting the current optimal path based on the transportation times of each local path and its last orbit segment to the end orbit segment.

[0049] In addition, when the logical instructions in the above-mentioned memory 420 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0050] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the overhead crane path dynamic planning method provided by the above-mentioned various methods. This method includes: a path update step: during the process of the target overhead crane performing a handling task, if the path update condition is met, then based on the current track section where the target overhead crane is located, the track map, and the local path length, perform a dynamic path planning step to obtain the current optimal path; an overhead crane control step: control the target overhead crane to travel along the current optimal path until the number of track sections passed by the target overhead crane is equal to the local path length, determine that the path update condition is met, and jump to the path update step; where the dynamic path planning step includes: perform local path planning based on the current track section where the target overhead crane is located and the track map to obtain multiple local paths with a length equal to the local path length; predict the transportation time from the last track section of the local path to the end track section of the target overhead crane; based on each local path and its transportation time from the last track section to the end track section, select the current optimal path.

[0051] In another aspect, the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is configured to execute the overhead crane path dynamic planning method provided above. The method includes: a path update step: during the process of the target overhead crane executing a handling task, if the path update condition is satisfied, perform a dynamic path planning step based on the current track segment where the target overhead crane is located, the track map, and the local path length to obtain the current optimal path; an overhead crane control step: control the target overhead crane to travel along the current optimal path until the number of track segments passed by the target overhead crane is equal to the local path length, determine that the path update condition is satisfied and jump to the path update step; where the dynamic path planning step includes: perform local path planning based on the current track segment where the target overhead crane is located and the track map to obtain multiple local paths with a length equal to the local path length; predict the transportation time from the last track segment of the local path to the end track segment of the target overhead crane; based on each local path and its transportation time from the last track segment to the end track segment, select the current optimal path.

[0052] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

[0053] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0054] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for dynamic planning of a crane path, characterized in that: include: Path updating step: when the target overhead crane is performing the handling task, if the path updating condition is met, a dynamic path planning step is performed based on the track segment, track map and local path length of the target overhead crane to obtain the current optimal path; Overhead crane control step: controlling the target overhead crane to move along the current optimal path until the number of track segments passed by the target overhead crane is equal to the length of the local path, determining that the path update condition is met and jumping to the path update step; Wherein, the dynamic path planning step includes: Performing local path planning based on the track segment where the target overhead travelling vehicle is currently located and the track map to obtain a plurality of local paths having lengths equal to the lengths of the local paths; Predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead travelling vehicle; The current optimal path is selected based on the transportation time from each local path and its last track segment to the terminal track segment.

2. The method for dynamic planning of overhead crane path according to claim 1, characterized in that: The local path planning is performed based on the track segment where the target overhead travelling vehicle is currently located and the track map to obtain a plurality of local paths having a length equal to the length of the local path, including: The time parameter of the current track segment is set to 0, the time parameters of other track segments are set to preset values, and a path containing only the current track segment is constructed and added to the local path set; When the length of any path in the local path set is less than the local path length, executing a local path search step; The local search step comprises: Obtain any one of the paths and delete the any one of the paths from the local path set; Based on the travel time from the last track segment of any path to its respective adjacent track segments, the time parameter of the last track segment and the time parameters of the respective adjacent track segments, the any path is extended to obtain a plurality of extended paths, and the extended paths are added to the local path set; the length of the extended path is 1 greater than the length of any path.

3. The method for dynamic planning of overhead crane path according to claim 2, characterized in that: The travel time from any track segment to any adjacent track segment is determined based on the regular travel time from any track segment to any adjacent track segment under non-congested conditions and a congestion penalty coefficient; the longer the average historical travel time from any track segment to any adjacent track segment, the greater the congestion penalty coefficient.

4. The method for dynamic planning of overhead crane path according to claim 1, characterized in that: The predicting of the transportation time from the last track segment of the local path to the terminal track segment of the target overhead travelling vehicle comprises: Obtaining graph feature vectors of a subgraph with the last track segment of the local path as a root node and a subgraph with the terminal track segment as a root node in the track map; Based on the graph feature vectors corresponding to the last track segment of the local path and the terminal track segment, the current number of overhead cranes on each track segment in the track map, and the load feature vectors of each processing equipment, the transportation time from the last track segment of the local path to the terminal track segment of the target overhead crane is predicted; the load feature vector of the processing equipment includes the number of transport tasks with the processing equipment as the starting point and the number of transport tasks with the processing equipment as the end point.

5. The method for dynamic planning of overhead crane path according to claim 1, characterized in that: The controlling the target overhead travelling vehicle to travel along the current optimal path until the number of track segments passed by the target overhead travelling vehicle is equal to the length of the local path further includes: In the process of controlling the target overhead traveling vehicle to move along the current optimal path, an observed track segment in the current optimal path is determined based on the local path length, and the local path length is updated based on congestion information of each track segment in each time period in the first track network subgraph corresponding to the observed track segment; The first track network subgraph corresponding to the observed track segment is the largest subgraph in the track map with the observed track segment as the root node; The updated local path length satisfies any of the following conditions: Taking the observed track segment as the starting point and the updated local path length as the maximum number of hops, in the second track network subgraph obtained from the first track network subgraph corresponding to the observed track segment, the congestion change rate of track segments exceeding a preset number is less than a preset threshold, and the updated local path length is less than or equal to a preset maximum value; The updated local path length is equal to the preset minimum value.

6. The method for dynamic planning of a crane path according to any one of claims 1 to 5, characterized in that: The selecting the current optimal path based on the transportation time from each local path and the last track segment thereof to the terminal track segment comprises: Calculate the transportation time of each local route; Based on the transportation time of each local path, the transportation time from the last track segment in each local path to the terminal track segment and the current adjustment coefficient, the global transportation time corresponding to each local path is determined; wherein, the higher the congestion level of the current track network, the greater the current adjustment coefficient.

7. A dynamic planning device for a crane path, characterized in that: include: A path updating unit, used for performing a dynamic path planning step based on the track segment, track map and local path length of the target overhead crane to obtain a current optimal path if the path updating condition is met during the target overhead crane performing the handling task; an overhead travelling vehicle control unit, configured to control the target overhead travelling vehicle to move along the current optimal path until the number of track segments passed by the target overhead travelling vehicle is equal to the length of the local path, determine that a path update condition is satisfied and call the path update unit; Wherein, the dynamic path planning step includes: Performing local path planning based on the track segment where the target overhead travelling vehicle is currently located and the track map to obtain a plurality of local paths having lengths equal to the lengths of the local paths; Predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead travelling vehicle; The current optimal path is selected based on the transportation time from each local path and its last track segment to the terminal track segment.

8. The overhead crane path dynamic planning device according to claim 7, characterized in that: The controlling the target overhead travelling vehicle to travel along the current optimal path until the number of track segments passed by the target overhead travelling vehicle is equal to the length of the local path further includes: In the process of controlling the target overhead traveling vehicle to move along the current optimal path, an observed track segment in the current optimal path is determined based on the local path length, and the local path length is updated based on congestion information of each track segment in each time period in the first track network subgraph corresponding to the observed track segment; The first track network subgraph corresponding to the observed track segment is the largest subgraph in the track map with the observed track segment as the root node; The updated local path length satisfies any of the following conditions: Taking the observed track segment as the starting point and the updated local path length as the maximum number of hops, in the second track network subgraph obtained from the first track network subgraph corresponding to the observed track segment, the congestion change rate of track segments exceeding a preset number is less than a preset threshold, and the updated local path length is less than or equal to a preset maximum value; The updated local path length is equal to the preset minimum value.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for dynamic planning of the overhead travelling vehicle path as claimed in any one of claims 1 to 6 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for dynamic planning of a crane path as claimed in any one of claims 1 to 6 is implemented.

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