Method for adjusting the number of AGVs in the material taking ramp of intelligent transportation system

Abstract

The present invention provides a method for adjusting the number of AGVs within a material ramp of an intelligent transportation system. During initial scheduling, data on the transportation frequency Fn of each material station is extracted, the number of AGVs Kn required for the material station is calculated, and the data is sorted to form a beat set R; the number ratio Tn of AGVs allocated to each material station is obtained; the priority level of AGV allocation to the material station is set according to the beat set R, and AGVs are allocated to the material station according to the number ratio Tn; during secondary adjustment, the number Wn of AGVs in each standby queue Qn is queried and sorted, and the beat set R is updated; the priority level of AGV allocation to the material station is updated according to the updated beat set R, and AGVs are allocated to the material station according to the number ratio Tn. The method of adjusting the number of AGVs within a material ramp of an intelligent transportation system of the present invention can avoid traffic congestion and the situation where some material stations are idle.

Description

Technical Field

[0001] The present invention relates to the field of AGV scheduling technology, and in particular to a method for adjusting the number of AGVs in a material-taking ramp of an intelligent transportation system. Background Art

[0002] When the intelligent transportation system is operating, the scheduling system will dispatch material-picking tasks to the AGVs in standby status. The AGVs in standby status will be assigned to perform the material-picking tasks and will select the material station closest to their standby point for the picking operation. If multiple AGVs in standby status select the same material station for the picking operation, it will cause multiple AGVs in standby status that select the same material station to be blocked in the material-picking ramp outside the material station, causing multiple AGVs in standby status to queue for a long time to wait for the picking operation, and the remaining material stations will be idle because they are not selected by AGVs, reducing the operating efficiency of the intelligent transportation system. Summary of the Invention

[0003] The purpose of the present invention is to overcome the problem that the existing scheduling system does not consider how to allocate AGVs in accordance with the situation of material sites when dispatching material picking tasks to AGVs in standby status, resulting in traffic congestion and some material sites being idle. A method for adjusting the number of AGVs in the material picking ramp of an intelligent transportation system is provided. By analyzing the transportation frequency Fn of each material site and the number of AGVs in the standby queue Qn of the material site, the number of AGVs in the material picking ramp is dynamically adjusted to avoid traffic congestion and some material sites being idle.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] Methods for adjusting the number of AGVs in the material taking ramp of the intelligent transportation system include:

[0006] Initial dispatch, including:

[0007] The dispatching system scans the working status of all G AGVs in the intelligent transportation system;

[0008] The dispatching system detects the information of all J material stations in the intelligent transportation system, selects a ramp in front of the material station as the material ramp, and sets a standby queue Qn in the material ramp, which are marked as Q1, Q2...Qj respectively. The number of AGVs in each standby queue Qn is 0;

[0009] The scheduling system extracts the data of the transportation frequency Fn of each material station and labels them as F1, F2…Fj;

[0010] According to the number of AGVs G, the transportation frequency Fn of each material station and the sum of the transportation frequencies Fn of all material stations in the intelligent transportation system P, the number of AGVs Kn required in the material ramp corresponding to each material station is obtained, which are marked as K1, K2...Kj respectively;

[0011] Sort K1, K2...Kj from large to small, and form a beat set R according to the order of the corresponding material sites after sorting several Kn;

[0012] According to the transportation frequency Fn and P of each material station, the number ratio Tn of AGVs allocated to each material station is obtained, which are marked as T1, T2...Tj respectively;

[0013] The dispatching system scans the number of AGVs in standby state H1;

[0014] The scheduling system sets the priority level of AGV allocation to the material site according to the order of the beat set R, and allocates AGVs to the material site according to the number ratio Tn of AGVs allocated to each material site;

[0015] The dispatching system dispatches a corresponding number of AGVs in standby state to enter the corresponding material-taking ramp;

[0016] Secondary adjustments include:

[0017] The dispatching system queries the number of AGVs Wn in each standby queue Qn, which are marked as W1, W2…Wj respectively;

[0018] Sort W1, W2…Wj from small to large, and update the beat set R in the order of the material sites corresponding to the sorted Wn;

[0019] The dispatching system rescans the number H2 of AGVs in standby status;

[0020] The scheduling system updates the priority level of AGV allocation to the material site according to the updated beat set R, and allocates AGVs to the material site according to the number ratio Tn of AGVs allocated to each material site;

[0021] The dispatching system dispatches a corresponding number of AGVs in standby state to enter the corresponding material-taking ramp.

[0022] Compared with the prior art, the method of adjusting the number of AGVs in the material taking ramp of the intelligent transportation system of the present invention has the following beneficial effects:

[0023] (1) The present invention coordinates all AGVs in standby state and available material stations, and diverts the AGVs in standby state to different material stations for material collection according to a specified ratio, thereby avoiding the problem that when the existing intelligent transportation system dispatches AGVs to perform material collection tasks, the AGV only chooses to move to the nearest material station to perform the material collection task, resulting in multiple AGVs moving to the same material station, resulting in a long time for traffic control, and the station being idle due to ignoring distant material stations, thereby improving the utilization rate of AGVs and the operating efficiency of on-site tasks;

[0024] (2) The present invention takes into account that the beats (transportation frequencies Fn) of different material stations are not necessarily the same. As the AGVs successively complete their material-picking tasks, the number of AGVs at each material station also changes. By adjusting the priority of each standby queue Qn through secondary adjustment, the number of AGVs moving to each material station is dynamically adjusted, thereby avoiding traffic congestion and long waiting time of AGVs caused by excessively long standby queues Qn.

[0025] (3) The present invention diverts AGVs to different material stations for material collection according to a specified ratio, and detects the number of AGVs in each standby queue Qn at regular intervals. By modifying the priority level of the standby queue Qn, the highest priority is given to the queue with the least actual number of AGVs, and the target station that has not yet entered the standby queue Qn is dispatched so that the AGV can enter the queue with the least actual number of AGVs first, so that the ratio of the number of AGVs Wn in each standby queue Qn is dynamically maintained at a ratio close to the transportation frequency Fn of each material station (W1:W2:……:Wj≈F1:F2:……:Fj), thereby realizing cyclic dynamic adjustment between queues and achieving the purpose of balancing the number of AGVs in the queues.

[0026] Furthermore, if the number Kn of AGVs required in the material ramp corresponding to the material station is a non-integer, the maximum integer not greater than Kn is assigned to Kn.

[0027] Furthermore, the remaining AGVs in standby status are adjusted twice in each cycle, leaving them for the next round of priority allocation of material sites.

[0028] Since the number of AGVs is not necessarily proportional to the number of material stations, there is a possibility that there will be AGVs on standby after the secondary adjustment of each cycle. The AGVs on standby left after the secondary adjustment of each cycle will be reserved for the next round of priority allocation of material stations, which can shorten the waiting time of AGVs.

[0029] Furthermore, Kn=G*(Fn / P); since G AGVs may all be in standby status in the initial state, it is necessary to consider the G AGVs.

[0030] Furthermore, Tn=Fn / P.

[0031] Furthermore, when the scheduling system schedules a corresponding number of AGVs in a standby state to enter a corresponding standby queue Qn, the following steps are included:

[0032] Locate the position of the AGV in standby state;

[0033] Calculate the distance from the AGV in standby state to a standby queue Qn;

[0034] The distances between AGVs and material stations are sorted from near to far to form an entry set Yn;

[0035] According to the proportion Tn of AGVs allocated to each material station, the corresponding number of AGVs are selected according to the order in which they enter the set Yn;

[0036] Schedule the selected AGV to move to the corresponding standby queue Qn;

[0037] The selected AGV is removed from the list of AGVs in the standby state, and the distance from the remaining AGVs in the standby state to another standby queue Qn is calculated, and the above steps are repeated.

[0038] In the present invention, in order to improve the scheduling efficiency of AGV, priority should be given to scheduling AGVs in standby state whose standby points are close to material stations, thereby shortening the AGV's moving distance, improving the system's operating efficiency, and extending the AGV's endurance.

[0039] Furthermore, the standby point of the AGV in the standby state is set on the material taking ramp.

[0040] The above setting method allows the AGV to enter the material-collecting ramp and wait when it is idle. When the AGV receives a transportation task, it can be dispatched to the corresponding material-collecting ramp to pick up the goods. In addition, this setting method can simplify the "method of adjusting the number of AGVs entering the material-collecting ramp" to "the method of adjusting the number of AGVs queuing at the standby point."

[0041] Furthermore, the time interval of the secondary adjustment cycle is 1-600 seconds, thereby forming a cyclic dynamic adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a flow chart of the present invention;

[0043] Figure 2 is a schematic diagram of the initial scheduling of an intelligent transportation system using the method of the present invention;

[0044] Figure 3 It is a schematic diagram of secondary adjustment of an intelligent transportation system using the method of the present invention. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present invention with reference to the accompanying drawings:

[0046] See also Figure 1 The method of adjusting the number of AGVs in the material-taking ramp of the intelligent transportation system in this embodiment includes initial scheduling and secondary adjustment.

[0047] Initial dispatch, including:

[0048] The dispatching system scans the working status of all G AGVs in the intelligent transportation system;

[0049] The dispatching system detects the information of all J material stations in the intelligent transportation system, selects a ramp in front of the material station as the material ramp, and sets a standby queue Qn in the material ramp, which are marked as Q1, Q2...Qj respectively. The number of AGVs in each standby queue Qn is 0;

[0050] The scheduling system extracts the data of the transportation frequency Fn of each material station and labels them as F1, F2…Fj;

[0051] According to the number of AGVs G, the transportation frequency Fn of each material station and the sum of the transportation frequencies Fn of all material stations in the intelligent transportation system P, the number of AGVs Kn required in the material ramp corresponding to each material station is obtained, which are marked as K1, K2...Kj respectively;

[0052] Sort K1, K2...Kj from large to small, and form a beat set R according to the order of the corresponding material sites after sorting several Kn;

[0053] According to the transportation frequency Fn and P of each material station, the number ratio Tn of AGVs allocated to each material station is obtained, which are marked as T1, T2...Tj respectively;

[0054] The dispatching system scans the number of AGVs in standby state H1;

[0055] The scheduling system sets the priority level of AGV allocation to the material site according to the order of the beat set R, and allocates AGVs to the material site according to the number ratio Tn of AGVs allocated to each material site;

[0056] The dispatching system dispatches a corresponding number of AGVs in standby state to enter the corresponding material-taking ramp;

[0057] Secondary adjustments include:

[0058] The dispatching system queries the number of AGVs Wn in each standby queue Qn, which are marked as W1, W2…Wj respectively;

[0059] Sort W1, W2…Wj from small to large, and update the beat set R in the order of the material sites corresponding to the sorted Wn;

[0060] The scheduling system rescans the number H2 of AGVs in standby status;

[0061] The scheduling system updates the priority level of AGV allocation to the material site according to the updated beat set R, and allocates AGVs to the material site according to the number ratio Tn of AGVs allocated to each material site;

[0062] The dispatching system dispatches a corresponding number of AGVs in a standby state to enter a corresponding material-taking ramp; the number of AGVs dispatched by the dispatching system to the corresponding material-taking ramp is an integer.

[0063] Furthermore, if the number Kn of AGVs required in the material ramp corresponding to the material station is a non-integer, the maximum integer not greater than Kn is assigned to Kn.

[0064] Furthermore, the remaining AGVs in standby status are adjusted twice in each cycle, leaving them for the next round of priority allocation of material sites.

[0065] Since the number of AGVs is not necessarily proportional to the number of material stations, there is a possibility that there will be AGVs on standby after the secondary adjustment of each cycle. The AGVs on standby left after the secondary adjustment of each cycle will be reserved for the next round of priority allocation of material stations, which can shorten the waiting time of AGVs.

[0066] Furthermore, Kn=G*(Fn / P); since G AGVs may all be in standby status in the initial state, it is necessary to consider the G AGVs.

[0067] Furthermore, Tn=Fn / P.

[0068] Furthermore, when the scheduling system schedules a corresponding number of AGVs in a standby state to enter a corresponding standby queue Qn, the following steps are included:

[0069] Locate the position of the AGV in standby state;

[0070] Calculate the distance from the AGV in standby state to a standby queue Qn;

[0071] The distances between AGVs and material stations are sorted from near to far to form an entry set Yn;

[0072] According to the proportion Tn of AGVs allocated to each material station, the corresponding number of AGVs are selected according to the order in which they enter the set Yn;

[0073] Schedule the selected AGV to move to the corresponding standby queue Qn;

[0074] The selected AGV is removed from the list of AGVs in the standby state, and the distance from the remaining AGVs in the standby state to another standby queue Qn is calculated, and the above steps are repeated.

[0075] In the present invention, in order to improve the scheduling efficiency of AGV, priority should be given to scheduling AGVs in standby state whose standby points are close to material stations, thereby shortening the AGV's moving distance, improving the system's operating efficiency, and extending the AGV's endurance.

[0076] Furthermore, the standby point of the AGV in the standby state is set on the material taking ramp.

[0077] The above setting method allows the AGV to enter the material-collecting ramp and wait when it is idle. When the AGV receives a transportation task, it can be dispatched to the corresponding material-collecting ramp to pick up the goods. In addition, this setting method can simplify the "method of adjusting the number of AGVs entering the material-collecting ramp" to "the method of adjusting the number of AGVs queuing at the standby point."

[0078] Furthermore, the time interval of the secondary adjustment cycle is 1-600 seconds, thereby forming a cyclic dynamic adjustment.

[0079] If the Kn and Wn of two material sites are the same, one will be processed first.

[0080] It should be noted that in actual production scenarios, the number of AGVs is far greater than the number of material stations. Therefore, it will not happen that a material station is not assigned to an AGV during the initial scheduling.

[0081] The present invention will be explained in detail below with reference to the accompanying drawings:

[0082] See also Figure 2 There are 4 material stations, namely No. 1, No. 2, No. 3 and No. 4, and the transportation frequencies Fn of the above four are set to F1:F2:F3:F4=a:a:2a:4a ​​(assuming F1 of No. 1 is a), where the transportation frequencies Fn of No. 1 and No. 2 are the same; the AGVs in standby state are represented by dots, and the number of AGVs in standby state H1 is set to 17; during the second adjustment, the number of new AGVs entering the standby state is 8, that is, during the second adjustment, the number of AGVs in standby state H2 is 9.

[0083] See also Figure 2 During the initial scheduling, based on the Tn of the four sites, it is calculated that station 1 needs to be allocated 2 AGVs, station 2 needs to be allocated 2 AGVs, station 3 needs to be allocated 4 AGVs, and station 4 needs to be allocated 8 AGVs. Based on the above results, the beat set R is formed, and the order of the values ​​in R is (4, 3, 2, 1).

[0084] See also Figure 2 First, 8 AGVs are assigned to No. 4, then 4 AGVs are assigned to No. 3, and then 2 AGVs are assigned to No. 1 and No. 2 respectively; the remaining 1 AGV is reserved for assignment during the second adjustment.

[0085] See also Figure 3 After a period of operation, all AGVs have completed the material collection operation, and some AGVs have completed other operations and are in a standby state; the second adjustment is started, and the number of AGVs in each standby queue Qn is queried. Among them, No. 4 has 4 AGVs remaining, No. 3 has 2 AGVs remaining, and No. 1 and No. 2 each have 1 AGV remaining; according to the number of AGVs in the standby queue Qn, they are sorted from small to large and the beat set R is updated. The order of the values ​​in R is (1, 2, 3, 4); according to the Tn of the four stations, it is calculated that No. 1 needs to be allocated 1 AGV, No. 2 needs to be allocated 1 AGV, No. 3 needs to be allocated 2 AGVs, and No. 4 needs to be allocated 4 AGVs;

[0086] See also Figure 3 First, allocate 1 AGV to No. 1 and No. 2, then allocate 2 AGVs to No. 3, and finally allocate 4 AGVs to No. 4. At this time, the number of AGVs in the four stations is 2:2:4:8, which is approximately equal to F1:F2:F3:F4 (which is 1:1:2:4); the remaining AGV will be assigned tasks during the second adjustment in the next cycle; the second adjustment is repeated.

[0087] Compared with the prior art, the method of adjusting the number of AGVs in the material taking ramp of the intelligent transportation system of the present invention has the following beneficial effects:

[0088] (1) The present invention coordinates all AGVs in standby state and available material stations, and diverts the AGVs in standby state to different material stations for material collection according to a specified ratio, thereby avoiding the problem that when the existing intelligent transportation system dispatches AGVs to perform material collection tasks, the AGV only chooses to move to the nearest material station to perform the material collection task, resulting in multiple AGVs moving to the same material station, resulting in a long time for traffic control, and the station being idle due to ignoring distant material stations, thereby improving the utilization rate of AGVs and the operating efficiency of on-site tasks;

[0089] (2) The present invention takes into account that the beats (transportation frequencies Fn) of different material stations are not necessarily the same. As the AGVs successively complete their material-picking tasks, the number of AGVs at each material station also changes. By adjusting the priority of each standby queue Qn through secondary adjustment, the number of AGVs moving to each material station is dynamically adjusted, thereby avoiding traffic congestion and long waiting time of AGVs caused by excessively long standby queues Qn.

[0090] (3) The present invention diverts AGVs to different material stations for material collection according to a specified ratio, and detects the number of AGVs in each standby queue Qn at regular intervals. By modifying the priority level of the standby queue Qn, the highest priority is given to the queue with the least actual number of AGVs, and the target station that has not yet entered the standby queue Qn is dispatched so that the AGV can enter the queue with the least actual number of AGVs first, so that the ratio of the number of AGVs Wn in each standby queue Qn is dynamically maintained at a ratio close to the transportation frequency Fn of each material station (W1:W2:……:Wj≈F1:F2:……:Fj), thereby realizing cyclic dynamic adjustment between queues and achieving the purpose of balancing the number of AGVs in the queues.

[0091] Based on the disclosure and teachings of the above description, those skilled in the art may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and modifications and variations of the present invention should also fall within the scope of protection of the claims of the present invention. In addition, although certain specific terms are used in this description, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. A method for adjusting the number of AGVs in a material taking ramp of an intelligent transportation system, characterized in that: include: Initial dispatch, including: The dispatching system scans the working status of all G AGVs in the intelligent transportation system; The dispatching system detects the information of all J material stations in the intelligent transportation system, selects a ramp in front of the material station as the material ramp, and sets a standby queue Qn in the material ramp, which are marked as Q1, Q2...Qj respectively. The number of AGVs in each standby queue Qn is 0; The scheduling system extracts the data of the transportation frequency Fn of each material station and labels them as F1, F2…Fj; According to the number of AGVs G, the transportation frequency Fn of each material station and the sum of the transportation frequencies Fn of all material stations in the intelligent transportation system P, the number of AGVs Kn required in the material ramp corresponding to each material station is obtained, which are marked as K1, K2...Kj respectively; Sort K1, K2...Kj from large to small, and form a beat set R according to the order of the corresponding material sites after sorting several Kn; According to the transportation frequency Fn and P of each material station, the number ratio Tn of AGVs allocated to each material station is obtained, which are marked as T1, T2...Tj respectively; The dispatching system scans the number of AGVs in standby state H1; The scheduling system sets the priority level of AGV allocation to the material site according to the order of the beat set R, and allocates AGVs to the material site according to the number ratio Tn of AGVs allocated to each material site; The dispatching system dispatches a corresponding number of AGVs in standby state to enter the corresponding material-taking ramp; Secondary adjustments include: The dispatching system queries the number of AGVs Wn in each standby queue Qn, which are marked as W1, W2…Wj respectively; Sort W1, W2…Wj from small to large, and update the beat set R in the order of the material sites corresponding to the sorted Wn; The dispatching system rescans the number H2 of AGVs in standby status; The scheduling system updates the priority level of AGV allocation to the material site according to the updated beat set R, and allocates AGVs to the material site according to the number ratio Tn of AGVs allocated to each material site; The dispatching system dispatches a corresponding number of AGVs in standby state to enter the corresponding material-taking ramp.

2. The method for adjusting the number of AGVs in a material taking ramp of an intelligent transportation system according to claim 1, characterized in that: If the number of AGVs Kn required in the material ramp corresponding to the material station is not an integer, the maximum integer not greater than Kn is assigned to Kn.

3. The method for adjusting the number of AGVs in a material taking ramp of an intelligent transportation system according to claim 2, characterized in that: The remaining AGVs in standby status are adjusted twice in each cycle, leaving them for priority allocation to material sites in the next round.

4. The method for adjusting the number of AGVs in a material taking ramp of an intelligent transportation system according to claim 1, characterized in that: Kn=G*(Fn / P).

5. The method for adjusting the number of AGVs in a material taking ramp of an intelligent transportation system according to claim 1, characterized in that: Tn=Fn / P.

6. The method for adjusting the number of AGVs in a material taking ramp of an intelligent transportation system according to claim 1, characterized in that: When the dispatching system dispatches a corresponding number of AGVs in standby state into the corresponding standby queue Qn, the following steps are included: Locate the position of the AGV in standby state; Calculate the distance from the AGV in standby state to a standby queue Qn; The distances between AGVs and material stations are sorted from near to far to form an entry set Yn; According to the proportion Tn of AGVs allocated to each material station, the corresponding number of AGVs are selected according to the order in which they enter the set Yn; Schedule the selected AGV to move to the corresponding standby queue Qn; The selected AGV is removed from the list of AGVs in the standby state, and the distance from the remaining AGVs in the standby state to another standby queue Qn is calculated, and the above steps are repeated.

7. The method for adjusting the number of AGVs in a material taking ramp of an intelligent transportation system according to claim 1, characterized in that: The standby point of the AGV in standby state is set on the material taking ramp.

8. The method for adjusting the number of AGVs in a material taking ramp of an intelligent transportation system according to claim 1, characterized in that: The time interval of the secondary adjustment cycle is 1-600 seconds.

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