A method, device, equipment and medium for replanning a crane path based on an AMHS system

Abstract

The present invention discloses a method, device, equipment and medium for replanning the path of an overhead crane based on an AMHS system, relates to the technical field of overhead crane path planning, solves the technical problem that the probability of congestion of the overhead crane in the process of transporting materials is high, and the key points of the technical solution are to adopt a more detailed path replanning strategy in dynamic path planning, and use parameters such as the number of different vehicles on the path, the working state of the overhead crane, the average speed and the discreteness to perform dynamic path replanning. The probability of congestion of the overhead crane in the process of transporting materials is greatly reduced, and the overall transport efficiency of the AMHS system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of overhead crane path planning, and in particular to an overhead crane path replanning method, device, equipment and medium based on an AMHS system. Background Art

[0002] The automatic material handling system (AMHS) is a key link in the semiconductor manufacturing industry. It can complete the fully automatic transportation of wafers between production equipment, and is an important guarantee for improving productivity, yield rate and equipment utilization. A safe and efficient automated material handling system can greatly shorten the waiting time of processing machines, thereby shortening the production cycle. And the many overhead cranes (OHTs) in the AMHS system complete these transportation tasks. The overhead cranes accurately deliver materials to each processing machine through the laid tracks. In the process of material transportation, it is inevitable to encounter traffic jams. At this time, the real-time path replanning function is crucial to alleviate traffic jams and improve system handling efficiency.

[0003] At present, most of the solutions to the congestion problem in the overhead crane transportation process are alleviated through some scheduling strategies or the calculation of the shortest path. However, this solution is for planning before material transportation and does not consider the real-time congestion problem during the specific transportation process. Some solutions also link the congestion probability with the number of vehicles running on the current path. The more vehicles there are, the higher the probability of path congestion. This solution based on the number of vehicles can certainly alleviate real-time congestion to a certain extent, but it does not consider the impact of different states during the operation of the overhead crane.

[0004] On the basis of the existing dispatching strategies and path planning, how to re-plan the path according to the real-time traffic conditions at the fork intersection to reduce the congestion rate during the overhead crane transportation process needs to be solved in this application. Summary of the invention

[0005] The present application provides a method, device, equipment and medium for replanning the path of an overhead crane based on an AMHS system, the technical purpose of which is to reduce the probability of congestion of the overhead crane during material transportation and improve the overall transportation efficiency of the AMHS system.

[0006] The above technical objectives of this application are achieved through the following technical solutions:

[0007] A method for replanning a crane path based on an AMHS system, comprising:

[0008] Step S0: the overhead crane starts the transport task, obtains the initial candidate path, and marks the road section where the faulty vehicle exists; wherein the road section where the faulty vehicle exists refers to the road section between two nodes where the faulty vehicle exists;

[0009] Step S1: Determine whether the marked road section is restored. If so, cancel the mark and the road section is included in the replanning to obtain the final alternative path; if not, avoid the road section to obtain the final alternative path;

[0010] Step S2: Check whether the absolute value of the difference in the number of vehicles between the alternative routes is greater than If yes, the path with fewer vehicles is selected as the optimal path and the process goes to step S7; otherwise, the current speed of each overhead travelling vehicle on the alternative path is obtained and the process goes to step S3;

[0011] Step S3: Determine whether there is a path in which all the crane speeds are not zero among the candidate paths. If there is a path in which all the crane speeds are not zero, select the path. If there is only one path in which all the crane speeds are not zero, take the path as the optimal path and go to step S7. If there are multiple paths in which all the crane speeds are not zero, go to step S5. If there is a crane with a speed of zero on each of the candidate paths, obtain the working status of the crane with a speed of zero and go to step S4.

[0012] Step S4: judging whether the overhead crane with a speed of zero is in a state of picking up or releasing cargo, including: if there is only one path where the overhead crane with a speed of zero is not in a state of picking up or releasing cargo, then selecting the path as the optimal path and going to step S7; if there are multiple paths where the overhead crane with a speed of zero is not in a state of picking up or releasing cargo, then going to step S5; if there are overhead cranes in a state of picking up or releasing cargo on all paths, then going to step S5;

[0013] Step S5: Calculate the average speed of the overhead travelling vehicle on each path, and compare and subtract the average speeds to see if the absolute value of the difference is greater than Make a judgment, if yes, select the path with a larger average speed as the optimal path and go to step S7, otherwise go to step S6;

[0014] Step S6: Calculate the discreteness on the path, and judge whether the discreteness is the same or whether there is a path with zero discreteness. If not, select the path with large discreteness as the optimal path and go to step S7. If yes, select The larger path is taken as the optimal path and the process goes to step S7; wherein, represents the distance between the current overhead crane and the nearest overhead crane on the jth path;

[0015] Step S7: output the optimal path; drive to the next node according to the selected optimal path, determine whether the node is the target destination, if so, end the process and complete the transportation process, if not, go to step S8, and update the alternative path at the node, delete the sections that have been traveled and the unreachable alternative paths, update the remaining paths to the alternative paths, and search the alternative paths and mark the sections where the faulty vehicle exists;

[0016] Step S8: Determine whether the node needs to be replanned, if yes, go to step S1, if no, continue to run to the next node, and go to step S9;

[0017] Step S9: Determine whether the node is the target endpoint, if so, end the process, if not, go to step S8.

[0018] Furthermore, in step S6, the dispersion is represented by the variance, and the variance is calculated by the distance between the overhead travelling vehicle on a certain alternative path and the current overhead travelling vehicle, which is represented as:

[0019] ;

[0020] in, represents the variance of the jth path; represents the first The distance between the crane and the current crane, the average distance ; represents the number of vehicles on the jth path.

[0021] A crane path replanning device based on an AMHS system, the crane path replanning device is used in a crane path replanning method, comprising:

[0022] In the pre-planning module, the overhead crane starts the transportation task, obtains the initial candidate path, and marks the road section where the faulty vehicle exists; the road section where the faulty vehicle exists refers to the road section between the two nodes where the faulty vehicle exists;

[0023] The first judgment module judges whether the marked road section is restored. If so, the mark is cancelled and the road section is involved in replanning to obtain the final alternative path; otherwise, the road section is avoided to obtain the final alternative path;

[0024] The second judgment module determines whether the absolute value of the difference in the number of vehicles between the alternative routes is greater than Make a judgment, if yes, select the path with fewer vehicles as the optimal path and go to the seventh judgment module, otherwise obtain the current speed of each overhead crane on the alternative path and go to the third judgment module;

[0025] The third judgment module judges whether there is a path in which the speed of the overhead crane is not zero among the alternative paths. If there is a path in which the speed of the overhead crane is not zero, the path is selected. If there is only one path in which the speed of the overhead crane is not zero, the path is taken as the optimal path and the process is transferred to the seventh judgment module. If there are multiple paths in which the speed of the overhead crane is not zero, the process is transferred to the first calculation module. If there is an overhead crane with a speed of zero in each alternative path, the working state of the overhead crane with a speed of zero is obtained, and the process is transferred to the fourth judgment module.

[0026] The fourth judgment module judges whether the overhead crane with a speed of zero is in a state of picking up or releasing goods, including: if there is only one path where the overhead crane with a speed of zero is not in a state of picking up or releasing goods, then the path is selected as the optimal path and the seventh judgment module is transferred; if there are multiple paths where the overhead crane with a speed of zero is not in a state of picking up or releasing goods, then the first calculation module is transferred; if there are overhead cranes in a state of picking up or releasing goods on all paths, then the first calculation module is transferred;

[0027] The first calculation module calculates the average speed of the overhead travelling vehicle on each path, and compares and subtracts the average speeds, and then proceeds to the fifth judgment module;

[0028] The fifth judgment module checks whether the absolute value of the difference is greater than Make a judgment, if yes, select the path with a larger average speed as the optimal path and go to the seventh judgment module, otherwise go to the second calculation module;

[0029] The second calculation module calculates the discreteness on the path and transfers to the sixth judgment module;

[0030] The sixth judgment module judges whether the discreteness is the same or whether there is a path with zero discreteness. If not, the path with large discreteness is selected as the optimal path and the seventh judgment module is turned to. If yes, the path with large discreteness is selected as the optimal path. The larger path is taken as the optimal path and transferred to the seventh judgment module; wherein, represents the distance between the current overhead crane and the nearest overhead crane on the jth path;

[0031] The seventh judgment module outputs the optimal path; according to the output optimal path, the vehicle drives to the next node and determines whether the node is the target destination. If so, the process ends and the transportation process is completed. If not, the process goes to the eighth judgment module and the alternative path is updated at the node, the sections that have been traveled and the alternative paths that are unreachable are deleted, and the remaining paths are updated as alternative paths. At the same time, the alternative paths are searched and the sections where the faulty vehicle exists are marked;

[0032] An eighth judgment module determines whether the node needs to be replanned. If so, the process proceeds to the first judgment module. If not, the process continues to run to the next node and proceeds to the ninth judgment module.

[0033] The ninth judgment module judges whether the node is the target end point, if so, the process ends, if not, it goes to the eighth judgment module.

[0034] An electronic device comprises a processor and a memory, wherein the memory stores a computer program executable by the processor, and the computer program is executed by the processor so that the processor can execute a method for replanning an overhead crane path.

[0035] A computer-readable storage medium stores a computer program, which implements a method for replanning a crane path when executed by a processor.

[0036] The beneficial effects of the present application are as follows: the method, device, equipment and medium for replanning the path of the overhead crane based on the AMHS system described in the present application adopt a more detailed path replanning strategy in dynamic path planning, and use parameters such as the number of different vehicles on the path, the working state of the overhead crane, the average speed and the discreteness to perform dynamic path replanning. The probability of congestion of the overhead crane during the material transportation process is greatly reduced, and the overall transportation efficiency of the AMHS system is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Flow chart of the overhead crane path replanning method in an embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solution of the present application will be described in detail below with reference to the accompanying drawings.

[0039] During the transportation process of an overhead crane (OHT), the transportation links are constantly changing, and the optimal path at a certain moment may not be the optimal path at the next moment. Therefore, it is necessary to adjust the paths of different operating conditions in a timely manner and replan the paths of the overhead crane. The dynamic path planning part of the overhead crane is based on the statically selected path combination. These alternative path combinations are multiple better paths obtained through some path planning algorithms. Each alternative path is composed of key nodes on the path. Composition, for example, the jth path Whenever there are more than or equal to two optional paths for the overhead crane at a key node, the overhead crane transportation path needs to be replanned until it reaches the destination.

[0040] The method for replanning the overhead crane path based on the AMHS system described in this application is as follows: Figure 1 As shown, specifically including:

[0041] Step S0: the overhead crane starts the transport task, obtains an initial candidate path, and marks the road section where the faulty vehicle exists; wherein the road section where the faulty vehicle exists refers to the road section between two nodes where the faulty vehicle exists.

[0042] Step S1: Determine whether the marked road section is restored. If so, cancel the mark and the road section participates in replanning to obtain the final alternative path; if not, avoid the road section to obtain the final alternative path.

[0043] Step S2: Check whether the absolute value of the difference in the number of vehicles between the alternative routes is greater than A judgment is made, if yes, a path with fewer vehicles is selected as the optimal path and the process goes to step S7, otherwise the current speed of each overhead crane on the alternative path is obtained and the process goes to step S3.

[0044] in Yes, depending on the number of overhead cranes in the system.

[0045] Step S3: Determine whether there is a path in which all the crane speeds are not zero among the alternative paths. If there is a path in which all the crane speeds are not zero, select the path. If there is only one path in which all the crane speeds are not zero, take the path as the optimal path and go to step S7. If there are multiple paths in which all the crane speeds are not zero, go to step S5. If there is a crane with a speed of zero on each alternative path, obtain the working status of the crane with a speed of zero and go to step S4.

[0046] Step S4: judging whether the overhead crane with a speed of zero is in the state of picking up or releasing cargo, including: if there is only one path where the overhead crane with a speed of zero is not in the state of picking up or releasing cargo, then selecting this path as the optimal path and going to step S7; if there are multiple paths where the overhead crane with a speed of zero is not in the state of picking up or releasing cargo, then going to step S5; if there are overhead cranes in the state of picking up or releasing cargo on all paths, then going to step S5.

[0047] Step S5: Calculate the average speed of the overhead travelling vehicle on each path, and compare and subtract the average speeds to see if the absolute value of the difference is greater than Make a judgment, if yes, select the path with a larger average speed as the optimal path and go to step S7, otherwise go to step S6.

[0048] in Yes. When there are fast and slow tracks, the speed of the overhead travelling vehicle on the path is normalized by dividing it by the maximum speed allowed by the current track and then calculating the average value. Configure in the [0,1] interval.

[0049] Step S6: Calculate the discreteness on the path, and judge whether the discreteness is the same or whether there is a path with zero discreteness. If not, select the path with large discreteness as the optimal path and go to step S7. If yes, select The larger path is taken as the optimal path and the process goes to step S7; wherein, Indicates the distance between the current overhead crane and the nearest overhead crane on the jth path.

[0050] Specifically, in step S6, the dispersion is represented by the variance, and the variance is calculated by the distance between the overhead travelling vehicle and the current overhead travelling vehicle on a certain alternative path, which is represented as:

[0051] ;

[0052] in, represents the variance of the jth path; represents the first The distance between the crane and the current crane, the average distance ; represents the number of vehicles on the jth path.

[0053] Step S7: Output the optimal path; drive to the next node according to the selected optimal path, and determine whether the node is the target destination. If so, end the process and complete the transportation process. If not, go to step S8 and update the alternative path at the node, delete the sections that have been traveled and the unreachable alternative paths, update the remaining paths to the alternative paths, and search the alternative paths and mark the sections where the faulty vehicle exists.

[0054] Step S8: Determine whether the node needs to be replanned, if so, go to step S1, if not, continue to run to the next node, and go to step S9.

[0055] Step S9: Determine whether the node is the target endpoint, if so, end the process, if not, go to step S8.

[0056] The overhead crane path re-planning device based on the AMHS system described in the present application includes a pre-planning module, a first judgment module, a second judgment module, a third judgment module, a first calculation module, a fourth judgment module, a second calculation module, a fifth judgment module, a sixth judgment module, a seventh judgment module, an eighth judgment module and a ninth judgment module.

[0057] The pre-planning module is used to obtain the initial alternative path when the overhead crane starts the transportation task, and mark the section where the faulty vehicle exists; wherein the section where the faulty vehicle exists refers to the section between two nodes where the faulty vehicle exists.

[0058] The first judgment module is used to judge whether the marked road section is restored. If so, the mark is cancelled and the road section is involved in replanning to obtain the final alternative path; otherwise, the road section is avoided to obtain the final alternative path.

[0059] The second judgment module is used to determine whether the absolute value of the difference in the number of vehicles between the alternative routes is greater than A judgment is made, if yes, a path with fewer vehicles is selected as the optimal path and the process goes to the seventh judgment module; otherwise, the current speed of each overhead crane on the alternative path is obtained and the process goes to the third judgment module.

[0060] The third judgment module is used to judge whether there is a path in which the speed of the overhead crane is not zero among the alternative paths. If there is a path in which the speed of the overhead crane is not zero, the path is selected; if there is only one path in which the speed of the overhead crane is not zero, the path is taken as the optimal path and the process is transferred to the seventh judgment module; if there are multiple paths in which the speed of the overhead crane is not zero, the process is transferred to the first calculation module; if there is an overhead crane with a speed of zero in each alternative path, the working status of the overhead crane with a speed of zero is obtained, and the process is transferred to the fourth judgment module.

[0061] The fourth judgment module is used to judge whether the overhead crane with a speed of zero is in the state of picking up and releasing goods, including: if there is only one path on which the overhead crane with a speed of zero is not in the state of picking up and releasing goods, then select this path as the optimal path and go to the seventh judgment module; if there are multiple paths on which the overhead crane with a speed of zero is not in the state of picking up and releasing goods, then go to the first calculation module; if there are overhead cranes in the state of picking up and releasing goods on all paths, then go to the first calculation module.

[0062] The first calculation module is used to calculate the average speed of the overhead travelling vehicle on each path, and compare and subtract the average speeds, and then transfer to the fifth judgment module.

[0063] The fifth judgment module is used to determine whether the absolute value of the difference is greater than Make a judgment, if yes, select the path with a larger average speed as the optimal path and go to the seventh judgment module, otherwise go to the second calculation module.

[0064] The second calculation module is used to calculate the discreteness on the path, and then transfer to the sixth judgment module.

[0065] The sixth judgment module is used to judge whether the discreteness is the same or whether there is a path with zero discreteness. If not, the path with large discreteness is selected as the optimal path and the seventh judgment module is turned to. If yes, the path with large discreteness is selected as the optimal path. The larger path is taken as the optimal path and transferred to the seventh judgment module; wherein, Indicates the distance between the current overhead crane and the nearest overhead crane on the jth path.

[0066] The seventh judgment module is used to output the optimal path; according to the output optimal path, the vehicle drives to the next node and determines whether the node is the target destination. If so, the process ends and the transportation process is completed. If not, the process goes to the eighth judgment module and the alternative path is updated at the node, the sections that have been traveled and the unreachable alternative paths are deleted, and the remaining paths are updated as alternative paths. At the same time, the alternative paths are searched and the sections where the faulty vehicles exist are marked.

[0067] The eighth judgment module is used to judge whether the node needs to be replanned. If so, it goes to the first judgment module. If not, it continues to run to the next node and goes to the ninth judgment module.

[0068] The ninth judgment module is used to judge whether the node is the target end point, if so, the process ends, if not, it goes to the eighth judgment module.

[0069] The above are exemplary embodiments of the present application, and the protection scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for replanning a crane path based on an AMHS system, characterized in that: include: Step S0: the overhead crane starts the transport task, obtains the initial candidate path, and marks the road section where the faulty vehicle exists; wherein the road section where the faulty vehicle exists refers to the road section between two nodes where the faulty vehicle exists; Step S1: Determine whether the marked road section is restored. If so, cancel the mark and the road section is included in the replanning to obtain the final alternative path; if not, avoid the road section to obtain the final alternative path; Step S2: Determine whether the absolute value of the difference in the number of vehicles between the alternative paths is greater than ΔM. If so, select the path with fewer vehicles as the optimal path and go to step S7. Otherwise, obtain the current speed of each overhead crane on the alternative path and go to step S3. Step S3: Determine whether there is a path in which all the crane speeds are not zero among the candidate paths. If there is a path in which all the crane speeds are not zero, select the path. If there is only one path in which all the crane speeds are not zero, take the path as the optimal path and go to step S7. If there are multiple paths in which all the crane speeds are not zero, go to step S5. If there is a crane with a speed of zero on each of the candidate paths, obtain the working status of the crane with a speed of zero and go to step S4. Step S4: judging whether the overhead crane with a speed of zero is in a state of picking up or releasing cargo, including: if there is only one path where the overhead crane with a speed of zero is not in a state of picking up or releasing cargo, then selecting the path as the optimal path and going to step S7; if there are multiple paths where the overhead crane with a speed of zero is not in a state of picking up or releasing cargo, then going to step S5; if there are overhead cranes in a state of picking up or releasing cargo on all paths, then going to step S5; Step S5: Calculate the average speed of the overhead travelling vehicle on each path, and compare and subtract the average speeds to determine whether the absolute value of the difference is greater than Δv. If so, select the path with the larger average speed as the optimal path and go to step S7; otherwise, go to step S6. Step S6: Calculate the discreteness on the path, and judge whether the discreteness is the same or whether there is a path with zero discreteness. If not, select the path with large discreteness as the optimal path and go to step S7. If yes, select The larger path is taken as the optimal path and the process goes to step S7; wherein, represents the distance between the current overhead crane and the nearest overhead crane on the jth path; Step S7: output the optimal path; drive to the next node according to the selected optimal path, determine whether the node is the target destination, if so, end the process and complete the transportation process, if not, go to step S8, and update the alternative path at the node, delete the sections that have been traveled and the unreachable alternative paths, update the remaining paths to the alternative paths, and search the alternative paths and mark the sections where the faulty vehicle exists; Step S8: Determine whether the node needs to be replanned, if yes, go to step S1, if no, continue to run to the next node, and go to step S9; Step S9: Determine whether the node is the target endpoint, if yes, end the process, if no, go to step S8; In step S6, the dispersion is represented by the variance, and the variance is calculated by the distance between the overhead travelling vehicle and the current overhead travelling vehicle on a certain alternative path, which is represented as: Among them, σ 2 (j) represents the variance of the jth path; Indicates the distance between the i-th overhead crane on the j-th path and the current overhead crane, the average distance M j represents the number of vehicles on the jth path.

2. A crane path replanning device based on the AMHS system, the crane path replanning device is used in the crane path replanning method according to claim 1, characterized in that: include: In the pre-planning module, the overhead crane starts the transportation task, obtains the initial candidate path, and marks the road section where the faulty vehicle exists; the road section where the faulty vehicle exists refers to the road section between the two nodes where the faulty vehicle exists; The first judgment module judges whether the marked road section is restored. If so, the mark is cancelled and the road section is involved in replanning to obtain the final alternative path; otherwise, the road section is avoided to obtain the final alternative path; The second judgment module judges whether the absolute value of the difference in the number of vehicles between the alternative paths is greater than ΔM. If so, the path with fewer vehicles is selected as the optimal path and the process proceeds to the seventh judgment module. Otherwise, the current speed of each overhead crane on the alternative path is obtained and the process proceeds to the third judgment module. The third judgment module judges whether there is a path in which the speed of the overhead crane is not zero among the alternative paths. If there is a path in which the speed of the overhead crane is not zero, the path is selected. If there is only one path in which the speed of the overhead crane is not zero, the path is taken as the optimal path and the process is transferred to the seventh judgment module. If there are multiple paths in which the speed of the overhead crane is not zero, the process is transferred to the first calculation module. If there is an overhead crane with a speed of zero in each alternative path, the working state of the overhead crane with a speed of zero is obtained, and the process is transferred to the fourth judgment module. The fourth judgment module judges whether the overhead crane with a speed of zero is in a state of picking up or releasing goods, including: if there is only one path where the overhead crane with a speed of zero is not in a state of picking up or releasing goods, then the path is selected as the optimal path and the seventh judgment module is transferred; if there are multiple paths where the overhead crane with a speed of zero is not in a state of picking up or releasing goods, then the first calculation module is transferred; if there are overhead cranes in a state of picking up or releasing goods on all paths, then the first calculation module is transferred; The first calculation module calculates the average speed of the overhead travelling vehicle on each path, and compares and subtracts the average speeds, and then proceeds to the fifth judgment module; The fifth judgment module judges whether the absolute value of the difference is greater than Δv. If so, the path with a larger average speed is selected as the optimal path and the process proceeds to the seventh judgment module. Otherwise, the process proceeds to the second calculation module. The second calculation module calculates the discreteness on the path and transfers to the sixth judgment module; The sixth judgment module judges whether the discreteness is the same or whether there is a path with zero discreteness. If not, the path with large discreteness is selected as the optimal path and the seventh judgment module is turned to. If yes, the path with large discreteness is selected as the optimal path. The larger path is taken as the optimal path and transferred to the seventh judgment module; wherein, represents the distance between the current overhead crane and the nearest overhead crane on the jth path; The seventh judgment module outputs the optimal path; according to the output optimal path, the vehicle drives to the next node and determines whether the node is the target destination. If so, the process ends and the transportation process is completed. If not, the process goes to the eighth judgment module and the alternative path is updated at the node, the sections that have been traveled and the alternative paths that are unreachable are deleted, and the remaining paths are updated as alternative paths. At the same time, the alternative paths are searched and the sections where the faulty vehicle exists are marked; An eighth judgment module determines whether the node needs to be replanned. If so, the process proceeds to the first judgment module. If not, the process continues to run to the next node and proceeds to the ninth judgment module. The ninth judgment module judges whether the node is the target end point, if so, the process ends, if not, it goes to the eighth judgment module.

3. An electronic device, characterized in that: The invention comprises a processor and a memory, wherein the memory stores a computer program executable by the processor, and the computer program is executed by the processor so that the processor can execute the overhead travelling vehicle path replanning method as claimed in claim 1.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the overhead crane path replanning method as claimed in claim 1 is implemented.

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