Overhead crane path dynamic planning method, device, electronic device and storage medium

Abstract

The present invention provides a method, device, electronic device and storage medium for dynamic planning of an overhead crane path. In the path updating step, a dynamic path planning step is performed based on the track segment where the target overhead crane is currently located, a track map and the length of the local path to obtain a current optimal path. In the overhead crane control step, the target overhead crane is controlled 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, and it is determined that the path updating condition is met and the process jumps to the path updating step. In the dynamic path planning step, local path planning is performed based on the track segment where the target overhead crane is currently located and the track map to obtain multiple local paths with a length equal to the length of the local path. 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. The rolling optimization strategy based on the fixed local path length improves the efficiency and flexibility of the overhead crane path planning method.

Description

Technical Field

[0001] The present invention relates to the technical field of path planning, and in particular to a method, device, electronic equipment and storage medium for dynamic planning of an overhead crane path. Background Art

[0002] Modern semiconductor manufacturing equipment in wafer fabs typically utilizes an automated material handling system (AMHS) to handle wafer transportation. The AMHS typically utilizes an overhead hoist transport (OHT) to transport wafers along a network of rails deployed on the fab's ceiling. To ensure process efficiency, planning the shortest possible routes for the OHTs responsible for transporting wafers is crucial. Current OHT path planning algorithms often 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 location of the OHT, and the status of the wafer fab's machines are constantly changing. Traffic conditions directly affect the travel time of a track segment. Therefore, as the OHT moves toward its destination, the actual travel time of the route changes dynamically, making static planning strategies difficult to adapt to dynamic traffic flow or unexpected events. Furthermore, dynamic planning algorithms can adapt to changing traffic conditions. However, when performing real-time path planning, dynamic planning algorithms search for all possible paths from the current node to the destination node (i.e., the end point of the overhead crane transport task). This large search space leads to high computational complexity. Furthermore, because dynamic path planning strategies require significant computing resources, traditional dynamic planning algorithms typically rely on heuristic functions. Unfortunately, the performance of dynamic planning algorithms that rely on heuristic functions depends on the quality of the heuristic functions. However, in the context of constantly changing traffic conditions, fixed heuristic functions may not be able to meet the needs of different scenarios. Updating the heuristic function in real time to adapt to these changes increases computational complexity, affecting the algorithm's real-time performance and responsiveness. Therefore, in order to meet the wafer handling needs of modern wafer fabs, it is necessary to design an overhead crane path planning algorithm that can adapt to the ever-changing traffic conditions while maintaining high efficiency. Summary of the Invention

[0004] The present invention provides a method, device, electronic device and storage medium for dynamically planning an overhead crane path, which are used to solve the defects of high complexity and poor real-time performance of path planning in the prior art.

[0005] The present invention provides a method for dynamically planning an overhead crane path, comprising:

[0006] Path updating step: During the process of the target overhead crane performing the transport 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;

[0007] An overhead crane control step: controlling the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane is equal to the length of the local path, determining that a path update condition is satisfied, and jumping to the path update step;

[0008] The dynamic path planning step includes:

[0009] Performing local path planning based on the track segment where the target overhead crane is currently located and the track map to obtain multiple local paths with lengths equal to the lengths of the local paths;

[0010] Predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead travelling vehicle;

[0011] The current optimal path is selected based on the transportation time from each local path and the last track segment thereof to the terminal track segment.

[0012] According to a method for dynamically planning an overhead crane path provided by the present invention, local path planning is performed based on the track segment where the target overhead crane is currently located and the track map to obtain multiple local paths with lengths equal to the lengths of the local paths, including:

[0013] Set the time parameter of the current track segment to 0, set the time parameters of other track segments to preset values, and construct a path that only includes the current track segment and add it to the local path set;

[0014] When the length of any path in the local path set is less than the local path length, performing a local path search step;

[0015] The local search step comprises:

[0016] Obtaining any one of the paths and deleting the any one of the paths from the local path set;

[0017] 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 paths is 1 greater than the length of the any path.

[0018] According to a method for dynamic planning of overhead crane paths provided by the present invention, 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.

[0019] According to a method for dynamic planning of an overhead crane path provided by the present invention, the method of predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead crane includes:

[0020] 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;

[0021] 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 transportation tasks with the processing equipment as the transportation starting point and the number of transportation tasks with the processing equipment as the transportation end point.

[0022] According to a method for dynamically planning an overhead crane path provided by the present invention, controlling the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane is equal to the length of the local path further includes:

[0023] In a process of controlling the target overhead traveling vehicle to travel along the current optimal path, determining an observed track segment in the current optimal path based on the local path length, and updating the local path length based on congestion information of each track segment in each time period in a first track network subgraph corresponding to the observed track segment;

[0024] 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;

[0025] The updated local path length satisfies any of the following conditions:

[0026] Taking the observed track segment as the starting point and the updated local path length as the maximum number of hops, in a 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;

[0027] The updated local path length is equal to the preset minimum value.

[0028] According to a method for dynamically planning an overhead crane path provided by the present invention, selecting a current optimal path based on each local path and the transportation time from the last track segment thereof to the terminal track segment includes:

[0029] Calculate the transportation time of each local route;

[0030] The global transport time corresponding to each local path is determined based on the transport time of each local path, the transport time from the last track segment in each local path to the terminal track segment, and the current adjustment coefficient; wherein, the higher the congestion level of the current track network, the larger the current adjustment coefficient.

[0031] The present invention also provides a device for dynamically planning an overhead crane path, comprising:

[0032] A path updating unit is configured to, when the target overhead crane is performing a handling task, perform 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 a path updating condition is met;

[0033] an overhead crane control unit, configured to control the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane is equal to the length of the local path, determine that a path update condition is satisfied, and call the path update unit;

[0034] The dynamic path planning step includes:

[0035] Performing local path planning based on the track segment where the target overhead crane is currently located and the track map to obtain multiple local paths with lengths equal to the lengths of the local paths;

[0036] Predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead travelling vehicle;

[0037] The current optimal path is selected based on the transportation time from each local path and the last track segment thereof to the terminal track segment.

[0038] According to the present invention, a dynamic planning device for an overhead crane path is provided, wherein the control of the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane is equal to the length of the local path further comprises:

[0039] In a process of controlling the target overhead traveling vehicle to travel along the current optimal path, determining an observed track segment in the current optimal path based on the local path length, and updating the local path length based on congestion information of each track segment in each time period in a first track network subgraph corresponding to the observed track segment;

[0040] 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;

[0041] The updated local path length satisfies any of the following conditions:

[0042] Taking the observed track segment as the starting point and the updated local path length as the maximum number of hops, in a 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;

[0043] The updated local path length is equal to the preset minimum value.

[0044] The present invention also provides 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, any of the above-described methods for dynamically planning an overhead crane path is implemented.

[0045] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for dynamically planning an overhead crane path as described above is implemented.

[0046] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements any of the above-mentioned methods for dynamically planning an overhead crane path.

[0047] The present invention provides a method, device, electronic device and storage medium for dynamic planning of an overhead crane path. In the path updating step, if the path updating condition is met, the dynamic path planning step is performed 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; in the overhead crane control step, the target overhead crane is controlled to move along the current optimal path until the number of track segments passed by the target overhead crane is equal to the local path length, and it is determined that the path updating condition is met and the process jumps to the path updating step. In the dynamic path planning step, local path planning is performed 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, and the transportation time from the last track segment of the local path to the terminal track segment of the target overhead crane is predicted. Based on the transportation time from each local path and its last track segment to the terminal track segment, the current optimal path is selected. The rolling optimization strategy based on the fixed local path length improves the efficiency and flexibility of the overhead crane path planning method. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 It is a flow chart of the method for dynamic planning of overhead crane paths provided by the present invention;

[0050] Figure 2 It is a flowchart of the dynamic path planning steps provided by the present invention;

[0051] Figure 3 It is a structural diagram of the overhead crane path dynamic planning device provided by the present invention;

[0052] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0053] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0054] Figure 1 FIG. 1 is a flow chart of the method for dynamically planning the path of an overhead crane provided by the present invention. Figure 1 As shown, the method includes:

[0055] Path updating step 110: During the process of the target overhead crane performing the transport 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;

[0056] Overhead crane control step 120: controlling the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane is equal to the length of the local path, determining that a path update condition is satisfied, and jumping to the path update step;

[0057] Among them, Figure 2 As shown, the dynamic path planning step includes:

[0058] Step 210 , performing local path planning based on the track segment where the target overhead travelling vehicle is currently located and the track map, and obtaining a plurality of local paths having a length equal to the length of the local path;

[0059] Step 220 , predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead travelling vehicle;

[0060] Step 230 : selecting a current optimal path based on each local path and the transportation time from the last track segment to the terminal track segment.

[0061] Here, in a dynamic production environment, the state of the track network, the location of the OHT, and the state of the machines in the wafer fab are constantly changing. Since traffic conditions directly affect the travel time of the track segment, when the OHT moves to the destination node, the actual travel time of the route will change dynamically. The traditional static global path planning method can no longer meet the requirements of real-time and flexibility. When the current dynamic planning algorithm performs real-time path planning, the search space is all possible paths from the current node to the target node, resulting in greater computational complexity. In addition, traditional dynamic planning algorithms usually rely on heuristic functions, but when traffic conditions are constantly changing, fixed heuristic functions may be difficult to meet the needs of different scenarios, and real-time updating of heuristic functions may lead to increased computational complexity, affecting the real-time and response speed of the algorithm. In response to the above problems, an embodiment of the present invention proposes a method for dynamic planning of overhead crane paths that combines local path planning with a dynamic update mechanism to improve the overall transportation efficiency of the system.

[0062] 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 overhead crane is currently located, the complete track map (which represents the spatial position relationship of each track segment in the track network), and the end point of the handling task. This will obtain an initial path and control the target overhead crane to start performing the handling task along the initial path. While the overhead crane is moving along the planned path to perform the handling task, the driving status of the target overhead crane is monitored in real time. When it is detected that the driving status of the target overhead crane meets the path update conditions, for example, the overhead crane has completed a local path of a preset length (i.e., the local path length described below), the path update operation is immediately triggered. After the path update operation is triggered, the system will perform dynamic planning steps based on the track segment where the target overhead crane is currently located, the track map, and the local path length to obtain the current optimal path.

[0063] During the dynamic path planning step, the system searches for all local paths equal to the length of the local path based on the track segment currently occupied by the target overhead crane and the track map information. A local path is a feasible path starting from the track segment currently occupied by the target overhead crane and passing through a number of track segments equal to the length of the local path. The system then predicts the transport time from the last track segment of each local path to the destination track segment of the target overhead crane's transport task. For each local path, a global transport time is determined as a comprehensive evaluation metric based on the cumulative transport time of the current local path (i.e., the transport time from the starting point to the end point of the local path) and the transport time from its last track segment to the destination track segment. The local path with the shortest global transport time is selected as the new current optimal path. The global transport time for each local path can be determined based on the cumulative transport time of each local path, the transport time from the last track segment to the destination track segment in each local path, and the current adjustment coefficient. The higher the current rail network congestion, the larger the current adjustment coefficient. For example, the global transport time for any local path can be calculated using the following formula:

[0064] T all = T + β × T remain

[0065] Here, T all is the global transportation time corresponding to any local path, T is the transportation time of the local path, T remain is the transportation time from the last track segment to the terminal track segment in the local path, and β is the current adjustment coefficient.

[0066] In some embodiments, local path planning can be performed based on the following steps:

[0067] The time parameter for the current track segment is set to 0, and the time parameters for other track segments are set to a preset value (a very large value). The time parameter for any track segment represents the travel time required to reach the target overhead travelling vehicle from the track segment currently located. A path containing only the current track segment is then constructed and added to the local path set. At this point, the local path set contains only this one path. If the length of any path in the local path set is less than the local path length, a local path search step is performed for that path.

[0068] The local search step includes: obtaining the path and deleting it from the local path set; then, based on the travel time from the last track segment of the 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, the path is extended to obtain a number of extended paths, and the extended paths are added to the local path set. Here, the length of the extended path is 1 greater than the length of the path. Specifically, when performing path extension, if the travel time from the last track segment of the path to any of its adjacent track segments plus the sum of the time parameter of the last track segment (assuming it is d) is less than the time parameter of the adjacent track segment, the adjacent track segment is added to the end of the path to obtain an extended path, and the time parameter of the adjacent track segment is updated to the aforementioned value d.

[0069] In some embodiments, the travel time from any track segment to any adjacent track segment is determined based on the normal travel time from the track segment to the adjacent track segment in an uncongested state and a congestion penalty coefficient. The longer the average historical travel time from the track segment to the adjacent track segment, the greater the congestion penalty coefficient. For example, the travel time from any track segment to any adjacent track segment can be calculated based on the following formula:

[0070] dist_btw(u,v)=edge(u,v)×(1+CongestionPenalty(u,v))

[0071] 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 regular travel time from the track segment to the above adjacent track segment under non-congested conditions, and CongestionPenalty is the congestion penalty coefficient.

[0072] In other embodiments, the transportation time from the last track segment of any local route to the terminal track segment of the target overhead travelling vehicle may be predicted based on the following method:

[0073] (1) Based on the track map, the last track segment and the terminal track segment of the local path are taken as root nodes respectively, and the corresponding subgraph structure is extracted. The subgraph can include a set of track segments that start from the root node and extend outward along the track network within a certain number of hops, so as to effectively capture the topological information and traffic conditions of the current track segment and its surrounding areas. Subsequently, based on the above subgraph structure, the graph feature vector of each subgraph is extracted. The graph feature vector may include but is not limited to: the connection relationship between track segments, the basic attributes of each track segment (such as length, allowed speed, historical traffic flow), the congestion level of adjacent track segments, node centrality and other comprehensive information, thereby forming a high-dimensional feature expression that can fully reflect the local track status.

[0074] (2) After obtaining the graph feature vectors of the local path end segment and the terminal track segment, the current number of overhead cranes in each track segment in the track map is further collected. As an important indicator of dynamic traffic load, the number of overhead cranes can effectively reflect the traffic pressure and potential delay risks of each track segment. In addition, the system also synchronously collects the load feature vectors of each processing equipment. The load feature vector includes the number of handling tasks with the processing equipment as the starting point and the number of handling tasks with the processing equipment as the end point. As the source or end point of the overhead crane handling task, the load condition of the processing equipment directly affects the queuing time after the arrival of the overhead crane and the waiting time for departure, so it is an important factor that cannot be ignored.

[0075] (3) After integrating the above information, the system uses a deep learning-based regression prediction model, such as a multi-layer perceptron (MLP), a graph neural network (GNN), or other lightweight prediction networks. It takes the graph feature vector of the local path end track segment, the graph feature vector of the terminal track segment, the number of overhead cranes in each track segment, and the load feature vector of the processing equipment as input features. After feature fusion and deep reasoning, it outputs the predicted transportation time.

[0076] Through the methods of the above-described embodiments, the system can accurately and in real time predict the estimated transport time from the last track segment of a local path to the target destination track segment during dynamic path planning. Furthermore, during the local path selection phase, the optimal path is selected based on the principle of minimizing overall transport time. Compared to traditional prediction methods that rely solely on the static characteristics of track segments or the current distribution of overhead cranes, this embodiment fully incorporates local track topology characteristics, traffic flow conditions, and processing equipment load factors, enabling a more comprehensive reflection of changes in the actual transportation environment, significantly improving the accuracy of path selection decisions and the overall system handling efficiency.

[0077] After the path update is complete, the system will control the overhead crane to continue moving along the new current optimal path until it reaches the mission endpoint or the path update condition is met again (the number of track segments traversed by the target overhead crane is equal to the local path length). It should be noted that when the path update condition is met, if the number of track segments traversed from the target overhead crane's current track segment to the destination track segment is less than or equal to the aforementioned local path length, any path planning algorithm can be directly called to perform path planning based on the current track segment and the destination track segment, resulting in a current optimal path to the destination track segment.

[0078] As can be seen, through this local path segmentation control and dynamic adjustment mechanism, the overhead crane can maintain high transportation efficiency and task completion rates in a dynamically changing rail transit environment. Traditional dynamic path planning algorithms use the global path (i.e., all paths from the current position to the destination) as the target for a large-scale path search, resulting in high computational complexity. In scenarios with large rail networks, this can easily lead to significant delays in path updates, significantly impacting the overall transportation efficiency and real-time performance of the system. In contrast, the dynamic local path planning and control scheme proposed in this embodiment of the present invention adopts a rolling optimization strategy based on a fixed local path length. Specifically, the system does not directly search for a complete path from the starting point to the destination. Instead, it plans a local path of limited length on the track map based on the current position of the target overhead crane. It then dynamically determines whether the path needs to be updated as the overhead crane moves along the local path. This approach effectively decomposes the path planning problem into a series of small-scale, continuous local optimization problems, significantly reducing the complexity of a single path calculation. Because only a fixed number of track segments need to be planned at a time, the proposed solution can rapidly adapt to real-time changes in rail transit conditions (such as track congestion, temporary outages, and traffic control), avoiding the computational bottlenecks inherent in traditional dynamic path planning methods due to global dependencies. Furthermore, by predicting the remaining travel time at the end of each local path and using it as a basis for selection, the proposed solution not only optimizes the local path but also ensures that the overall transport process continues to progress toward the global optimal destination, thus achieving consistency between local optimality and global objectives.

[0079] The setting of the local path length has a significant impact on the dynamic path planning method described above. Specifically, the local path length should not be too large. If the local path length is set too long, the number of track segments involved in each local path planning operation increases, significantly increasing the computational complexity of the local path search. Furthermore, a long local path length also limits the overhead crane's ability to adjust during operation. If rail traffic conditions change (such as local congestion or temporary failures), timely path updates and optimizations are difficult, reducing the system's flexibility and adaptability to dynamic changes. On the other hand, the local path length should not be too small. If the local path length is set too short, the overhead crane will need to replan its path more frequently during the transport process. Although the range of a single path search is smaller, the increased frequency of path updates also increases the cumulative path planning overhead, which in turn increases the overall computational complexity, increases system resource utilization, and affects transport efficiency and response speed. Therefore, in some embodiments, the local path length can be appropriately determined based on the changing traffic conditions of each track segment in the rail network to achieve a good balance between path search overhead and system flexibility.

[0080] Specifically, while the target overhead crane is traveling along the current optimal path (i.e., before the next path update step is triggered), an observation track segment within the current optimal path is determined based on the current local path length. The observation track segment is the kth track segment from the starting point in the current optimal path, where k is the current local path length. This observation track segment serves as a reference for updating the local path length. Subsequently, the local path length is updated based on congestion changes for each track segment in the first rail network subgraph corresponding to the observation track segment. Specifically, the first rail network subgraph corresponding to the observation track segment is the largest subgraph (the deepest subgraph) extracted from the rail map with the observation track segment as its root node. This subgraph encompasses all track segments and connections within a certain number of hops from the observation track segment, reflecting the congestion situation in the local area near the observation track segment. The system monitors and collects congestion information for the track segments in the first rail network subgraph in real time during each time period. This congestion information includes, but is not limited to, the number of overhead cranes on each track segment in each time period and the average travel time for each time period. Based on this congestion information, the system can determine the congestion trends of each track segment and calculate the congestion change rate for each track segment. The congestion change rate refers to the degree of change in traffic flow within a track segment over a certain period of time and can be derived based on the variance of the congestion information for the corresponding track segment within each time period. Based on the collected congestion information for each track segment in the first track network subgraph at each time period, the system will dynamically adjust the local path length required for the next path update.

[0081] Specifically, the updated local path length meets the following conditions: With the observed track segment as the starting point and the updated local path length as the maximum number of hops, the congestion change rate for more than a preset number of track segments in the second rail network subgraph obtained from the first rail network subgraph corresponding to the observed track segment is less than a preset threshold, and the updated local path length is less than or equal to a preset maximum value. This allows the system to flexibly adjust path lengths based on predicted traffic flow, avoiding unnecessary congestion caused by overly long paths or frequent path updates caused by overly short paths.

[0082] Alternatively, the updated local path length is equal to a preset minimum value.

[0083] In some embodiments, the local path length may be updated as follows:

[0084] Starting from the observed track segment, advance k (the initial value of k is 1) jumps along the edge in the first track network subgraph corresponding to the observed track segment. If there are more than a preset number of track segments with a congestion change rate less than a preset threshold among the track segments passed through and the current value of k is less than the preset maximum value, then k is increased by 1 and the above operation is repeated; if the number of track segments with a congestion change rate less than the preset threshold among the track segments passed through is less than the preset number or the current value of k is equal to the preset maximum value, then the larger value between the current value of k and the preset minimum value is determined as the updated local path length.

[0085] Once the local path length is updated, the system will perform dynamic path planning based on the new local path length the next time a path update operation is triggered. Through this embodiment's local path length update method, the system can dynamically adjust the local path length of the target overhead crane, ensuring that when rail network congestion changes, it can quickly respond to changes in track conditions, avoiding efficiency losses or congestion caused by local paths that are too long or too short, thereby significantly improving the overall efficiency of overhead crane handling operations.

[0086] In summary, the method provided by the embodiment of the present invention obtains the current optimal path by executing the dynamic path planning step based on the current track segment of the target overhead crane, the track map and the local path length if the path update condition is met in the path update step; in the overhead crane control step, the target overhead crane is controlled to move along the current optimal path until the number of track segments passed by the target overhead crane is equal to the local path length, determining that the path update condition is met and jumping to the path update step, wherein in the dynamic path planning step, local path planning is performed based on the current track segment of the target overhead crane 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 segment of the local path to the terminal track segment of the target overhead crane, selecting the current optimal path based on the transportation time from each local path and its last track segment to the terminal track segment, and improving the efficiency and flexibility of the overhead crane path planning method based on the rolling optimization strategy with a fixed local path length.

[0087] The following describes the overhead crane path dynamic planning device provided by the present invention. The overhead crane path dynamic planning device described below and the overhead crane path dynamic planning method described above can be referenced to each other.

[0088] Based on any of the above embodiments, Figure 3 Schematic diagram of the structure of the overhead crane path dynamic planning device provided by the present invention, such as Figure 3 As shown, the device includes:

[0089] A path updating unit 310 is configured to perform 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 a path update condition is met during the target overhead crane's execution of the transport task.

[0090] an overhead crane control unit 320 for controlling the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane is equal to the length of the local path, determining that a path update condition is satisfied and invoking the path update unit;

[0091] The dynamic path planning step includes:

[0092] Performing local path planning based on the track segment where the target overhead crane is currently located and the track map to obtain multiple local paths with lengths equal to the lengths of the local paths;

[0093] Predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead travelling vehicle;

[0094] The current optimal path is selected based on the transportation time from each local path and the last track segment thereof to the terminal track segment.

[0095] The device provided by the embodiment of the present invention obtains the current optimal path by executing the dynamic path planning step based on the track segment where the target overhead crane is currently located, the track map and the local path length if the path update condition is met in the path update step; in the overhead crane control step, the target overhead crane is controlled to move along the current optimal path until the number of track segments passed by the target overhead crane is equal to the local path length, determining that the path update condition is met and jumping to the path update step, wherein in the dynamic path planning step, local path planning is performed based on the track segment where the target overhead crane is currently 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 segment of the local path to the terminal track segment of the target overhead crane, selecting the current optimal path based on the transportation time from each local path and its last track segment to the terminal track segment, and improving the efficiency and flexibility of the overhead crane path planning method based on the rolling optimization strategy with a fixed local path length.

[0096] Based on any of the above embodiments, 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 multiple local paths having a length equal to the length of the local path, including:

[0097] Set the time parameter of the current track segment to 0, set the time parameters of other track segments to preset values, and construct a path that only includes the current track segment and add it to the local path set;

[0098] When the length of any path in the local path set is less than the local path length, performing a local path search step;

[0099] The local search step comprises:

[0100] Obtaining any one of the paths and deleting the any one of the paths from the local path set;

[0101] 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 paths is 1 greater than the length of the any path.

[0102] Based on any of the above embodiments, 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 the 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.

[0103] Based on any of the above embodiments, 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 includes:

[0104] 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;

[0105] 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 transportation tasks with the processing equipment as the transportation starting point and the number of transportation tasks with the processing equipment as the transportation end point.

[0106] Based on any of the above embodiments, the controlling the target overhead traveling vehicle to travel along the current optimal path until the number of track segments traversed by the target overhead traveling vehicle is equal to the length of the local path further includes:

[0107] In a process of controlling the target overhead traveling vehicle to travel along the current optimal path, determining an observed track segment in the current optimal path based on the local path length, and updating the local path length based on congestion information of each track segment in each time period in a first track network subgraph corresponding to the observed track segment;

[0108] 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;

[0109] The updated local path length satisfies any of the following conditions:

[0110] Taking the observed track segment as the starting point and the updated local path length as the maximum number of hops, in a 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;

[0111] The updated local path length is equal to the preset minimum value.

[0112] Based on any of the above embodiments, selecting the current optimal path based on each local path and the transportation time from the last track segment to the terminal track segment includes:

[0113] Calculate the transportation time of each local route;

[0114] The global transport time corresponding to each local path is determined based on the transport time of each local path, the transport time from the last track segment in each local path to the terminal track segment, and the current adjustment coefficient; wherein, the higher the congestion level of the current track network, the larger the current adjustment coefficient.

[0115] Figure 4 Schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 4 As shown, the electronic device may include: a processor (processor) 410, a memory (memory) 420, a communication interface (Communications Interface) 430 and a communication bus 440, wherein the processor 410, the memory 420, and the communication interface 430 communicate with each other through the communication bus 440. The processor 410 can call the logic instructions in the memory 420 to execute the dynamic path planning method of the overhead crane, which includes: a path updating step: during the target overhead crane performing the transportation task, if the path updating condition is met, the dynamic path planning step is performed based on the current track segment of the target overhead crane, the track map and the local path length to obtain the current optimal path; an 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 local path length, determining that the path updating condition is met and jumping to the path updating step; wherein, the dynamic path planning step includes: performing local path planning based on the current track segment of the target overhead crane 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 segment of the local path to the terminal track segment of the target overhead crane; and selecting the current optimal path based on the transportation time of each local path and its last track segment to the terminal track segment.

[0116] Furthermore, the logic instructions in the aforementioned memory 420 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0117] On the other hand, the present invention further provides a computer program product, comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions. When the program instructions are executed by a computer, the computer is capable of executing the overhead crane path dynamic planning method provided by each of the above methods, the method comprising: a path updating step: during a target overhead crane performing a transport task, if a path updating condition is satisfied, a dynamic path planning step is performed based on the track segment currently located by the target overhead crane, a track map, and a local path length to obtain a current optimal path; an overhead crane control step: controlling the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane equals the local path length, determining that the path updating condition is satisfied, and jumping to the path updating step; wherein the dynamic path planning step comprises: performing local path planning based on the track segment currently located by the target overhead crane and the track map to obtain multiple local paths having a length equal to the local path length; predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead crane; and 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.

[0118] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the above-mentioned methods for dynamically planning a path for an overhead crane, the method comprising: a path updating step: during the target overhead crane performing a handling task, if a path updating condition is satisfied, a dynamic path planning step is performed based on the track segment where the target overhead crane is currently located, a track map, and a local path length to obtain a current optimal path; an 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 local path length, determining that the path updating condition is satisfied and jumping to the path updating step; wherein the dynamic path planning step comprises: performing local path planning based on the track segment where the target overhead crane is currently located and a track map to obtain multiple local paths with a length equal to the local path length; predicting the transportation time from the last track segment of the local path to the terminal track segment of the target overhead crane; and selecting the current optimal path based on the transportation time from each local path and its last track segment to the terminal track segment.

[0119] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0120] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for dynamic planning of an overhead crane path, characterized in that: include: Path updating step: During the process of the target overhead crane performing the transport 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; An overhead crane control step: controlling the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane is equal to the length of the local path, determining that a path update condition is satisfied, and jumping to the path update step; The dynamic path planning step includes: Performing local path planning based on the track segment where the target overhead crane is currently located and the track map to obtain multiple local paths with 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; Selecting a current optimal path based on the transportation time from each local path and the last track segment thereof to the terminal track segment; The controlling the target overhead traveling vehicle to travel along the current optimal path until the number of track segments traversed by the target overhead traveling 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 a first track network subgraph corresponding to the observed track segment; the observed track segment is the kth track segment starting from the starting point in the current optimal path, where k is the current local path length; 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 a 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.

2. The method for dynamic planning of overhead crane paths 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 multiple local paths having lengths equal to the lengths of the local paths, including: Set the time parameter of the current track segment to 0, set the time parameters of other track segments to preset values, and construct a path that only includes the current track segment 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, performing a local path search step; The local search step comprises: Obtaining any one of the paths and deleting 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 paths is 1 greater than the length of the 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 the 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 includes: 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 transportation tasks with the processing equipment as the transportation starting point and the number of transportation tasks with the processing equipment as the transportation end point.

5. The method for dynamic planning of an overhead crane path according to any one of claims 1 to 4, characterized in that: The selecting of the current optimal path based on the transportation time from each local path and the last track segment thereof to the terminal track segment includes: Calculate the transportation time of each local route; The global transport time corresponding to each local path is determined based on the transport time of each local path, the transport time from the last track segment in each local path to the terminal track segment, and the current adjustment coefficient; wherein, the higher the congestion level of the current track network, the larger the current adjustment coefficient.

6. A dynamic planning device for an overhead crane path, characterized in that: include: A path updating unit is configured to, when the target overhead crane is performing a handling task, perform 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 a path updating condition is met; an overhead crane control unit, configured to control the target overhead crane to move along the current optimal path until the number of track segments traversed by the target overhead crane is equal to the length of the local path, determine that a path update condition is satisfied, and call the path update unit; The dynamic path planning step includes: Performing local path planning based on the track segment where the target overhead crane is currently located and the track map to obtain multiple local paths with 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; Selecting a current optimal path based on the transportation time from each local path and the last track segment thereof to the terminal track segment; The controlling the target overhead traveling vehicle to travel along the current optimal path until the number of track segments traversed by the target overhead traveling 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 a first track network subgraph corresponding to the observed track segment; the observed track segment is the kth track segment starting from the starting point in the current optimal path, where k is the current local path length; 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 a 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.

7. 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 overhead crane path dynamic planning method according to any one of claims 1 to 5 is implemented.

8. 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 an overhead crane path as claimed in any one of claims 1 to 5 is implemented.

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