Dynamic idle crown block cruising method

Abstract

The invention relates to a dynamic idle crown block cruising method, which is used for a material handling system and comprises the following steps: when a newly added idle crown block exists in a working area, judging whether the newly added idle crown block is the unique potential idle crown block in the current working area or not; if the newly added idle crown block is not the unique potential idle crown block in the current working area, judging whether the working area without the potential idle crown block exists in the system or not; if the working area without the potential idle crown block exists in the system, selecting the working area without the potential idle crown block as a target working area according to the priority sequence of task load from high to low; and taking the idle crown block staying for the longest time in the current working area as a mobile idle crown block, and driving to the target working area. According to the invention, the mobility of idle crown blocks in the whole system is optimized.

Description

Technical Field

[0001] The invention relates to a material handling scheduling technology, and in particular to a dynamic idle overhead crane cruising method. Background Art

[0002] It is a common requirement in the production process to realize automatic handling and buffer storage of materials between production line processes through the control and scheduling of the software system in accordance with the instructions of the production system.

[0003] Take the automatic material handling system (AMHS) as an example. The automatic material handling system (AMHS) is an important technology in the development of the semiconductor industry. In the material handling and storage system, many machines and tracks form a work area (intrabay), and a high-speed transportation track (interbay) is set in the center of the work area. The overhead crane (OHT) is responsible for the handling work in the AMHS. To achieve a safe and efficient handling function, it is necessary to control each link. The working status of the overhead crane mainly includes receiving status, delivery status, and idle status. Generally, after completing the delivery task, the overhead crane will enter the idle state until it receives a task request again. How to arrange the patrol plan of these idle overhead cranes has a great impact on the efficiency of the overhead crane receiving goods and the smooth transportation of working vehicles.

[0004] In the schemes for controlling the cruising of idle overhead cranes, it is assumed that there are sideways or fixed parking areas to store idle overhead cranes. This method will result in uneven distribution of idle overhead cranes as the system runs, and the average delivery time is very long. Furthermore, such schemes must also set up a large number of sideways for parking idle overhead cranes. Other schemes aim at the situation where there is no parking area, and propose to let the idle overhead cranes cruise in the current work area or stay in place after completing the task. However, during the operation of the system, the generation and distribution of tasks are not uniform, and such schemes will cause poor mobility of idle overhead cranes.

[0005] Similar technical problems also exist in other production areas where material handling and vehicle storage are required. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention discloses a method for cruising a dynamic idle overhead crane.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A dynamic idle overhead crane patrol method is used in a material handling system, wherein the material handling system includes a plurality of work areas; an idle overhead crane, a cargo-releasing overhead crane and / or a cargo-receiving overhead crane are provided in the work area; the patrol method includes the following steps:

[0009] When a newly added idle crane is added in a work area, it is determined whether the newly added idle crane is the only potential idle crane in the current work area; the potential idle cranes are idle cranes and cargo cranes; if the newly added idle crane is the only potential idle crane in the current work area, the original state is maintained;

[0010] If the newly added idle overhead crane is not the only potential idle overhead crane in the current work area, determine whether there is a work area without potential idle overhead cranes in the system; if there is a work area without potential idle overhead cranes in the system, check whether there is a work area without potential idle overhead cranes in order of priority from high to low task volume and select it as the target work area; and make the idle overhead crane that stays the longest in the current work area as the mobile idle overhead crane and drive it to the target work area.

[0011] Its further technical solution is that when the mobile idle overhead crane arrives at the entrance of a passing work area during the process of driving towards the target work area, it determines whether the current passing work area is the target work area; if the current passing work area is the target work area, the mobile idle overhead crane enters the target work area for patrol; if the current passing work area is not the target work area, it continues to run to the next passing work area and determines whether it is the target work area.

[0012] A further technical solution is to set the upper limit of the time that the idle overhead crane stays in the working area to T;

[0013] When the mobile idle overhead crane arrives at the entrance of a passing work area, if it is determined that the current passing work area is not the target work area, it is determined whether there is a replaceable idle overhead crane with a patrol time exceeding T / 2 in the current passing work area. If there is a replaceable idle overhead crane with a patrol time exceeding T / 2 in the current passing work area, the mobile idle overhead crane enters the current passing work area and is replaced with the replaceable idle overhead crane. The replaceable idle overhead crane continues to run to the next passing work area as the new mobile idle overhead crane, and determines whether it is the target work area; if there is no replaceable idle overhead crane with a patrol time exceeding T / 2 in the current passing work area, the mobile idle overhead crane continues to run to the next passing work area, and determines whether it is the target work area.

[0014] Its further technical solution is: if there is no work area without potential idle overhead cranes in the system, then determine whether there are idle overhead crane positions in the current highest priority work area category in descending order of priority of task volume; if there is a work area with idle overhead crane positions in the current highest priority work area category, then select the work area with the least idle overhead cranes as the target work area; if there is no work area with idle overhead crane positions in the current highest priority work area category, then continue to determine whether the next second highest priority work area has idle overhead crane positions; if there are no idle overhead crane positions in the work areas of all work area categories, then maintain the original state.

[0015] Its further technical solution is that the number of vehicles in the jth working area is recorded as m j , the upper limit of the potential idle crane in the jth work area is

[0016] After the mobile idle crane enters the target work area and cruises, it is determined whether the number of potential idle cranes in the target work area is greater than If the number of potentially idle cranes in the target work area is greater than Idle overhead cranes outside the target work area are prohibited from entering.

[0017] A further technical solution is that if the number of potential idle overhead cranes in the target work area is greater than It is allowed that an idle overhead crane outside the current work area can be replaced with an idle overhead crane within the current work area, and after the cargo-releasing overhead crane enters the current work area, the idle overhead crane with the longest cruising time is designated as being in a state of exceeding restrictions; and the crane in a state of exceeding restrictions is designated as a newly added idle overhead crane.

[0018] The further technical solution is to set the maximum number of vehicles allowed to exist simultaneously in the jth work area to If the number of potentially idle cranes in the target work area is not greater than Then determine whether the total number of vehicles in the target work area is greater than If the total number of vehicles in the target work area is greater than It is determined whether there is an idle overhead crane in the target work area; if there is an idle overhead crane in the target work area, the idle overhead crane with the longest cruising time is designated as an out-of-restriction state; and the crane in the out-of-restriction state is designated as a newly added idle overhead crane; if there is no idle overhead crane in the target work area, the original state is maintained.

[0019] A further technical solution is to set an upper limit of the time that an idle overhead crane can stay in the work area as T; if it is judged that the total number of cranes in the target work area is not greater than It is determined whether the idle overhead crane stays in the target work area for a time greater than T. If so, the idle overhead crane that exceeds the maximum stay time T is designated as being in an out-of-restriction condition state; and the crane in the out-of-restriction condition state is designated as a newly added idle overhead crane.

[0020] A further technical solution is that, in the step of maintaining the original state, if a new idle overhead crane or a task overhead crane enters the work area, it is directly determined whether the number of potential idle overhead cranes in the target work area is greater than Determine whether the total number of vehicles in the target work area is greater than And / or a step of judging whether the idle mobile crane stays in the target work area for a time greater than T; the task crane is a receiving crane or a releasing crane.

[0021] A further technical solution is that the system adjustable parameters can be adjusted so as to reduce the average delivery time without affecting the overall average delivery time; the system adjustable parameters are the upper limit of potential idle cranes. and the upper limit T of the idle crane's stay time in the work area; the adjustment method is:

[0022] Set the initial values ​​of the system's adjustable parameters, count the average pick-up time of idle overhead cranes in the work area, and calculate the variance and mean;

[0023] Increase the initial value and obtain the adjusted value, and observe the variance and mean of the average delivery time;

[0024] When both the variance and the mean decrease, the adjusted value is judged to be better than the initial value;

[0025] When both the variance and the mean value increase, reduce the adjusted value and observe the variance and mean value of the average pickup time of the idle overhead cranes in each work area again.

[0026] The beneficial effects of the embodiments of the present invention are as follows:

[0027] The embodiment of the present invention is designed for the patrol scheme of idle overhead cranes, mainly to optimize the mobility of idle overhead cranes in the overall system, by classifying many work areas according to the amount of tasks, setting priorities to allocate idle vehicles, and setting some conditions to drive idle overhead cranes to patrol the entire system. It aims to reduce the time for idle overhead cranes to receive goods, reduce the impact on task overhead cranes, and improve the operating efficiency of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of a material handling system in an embodiment of the present invention.

[0029] Figure 2 Flow chart of the dynamic idle overhead crane cruising method in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Still taking the semiconductor field as an example, in the existing technology, most studies on the treatment of idle cranes assume that there are sideways or fixed parking areas to store idle cranes. This method not only causes uneven distribution of idle cranes as the system operates, but also ignores the benefits of idle crane cruising in shortening the overall average delivery time. Moreover, when designing many crane systems, a large number of sideways are not designed for parking idle cranes.

[0031] Therefore, some other solutions are proposed for the situation where there is no parking area. After completing the task, the idle overhead crane cruises in the current work area, or stays in place and other task vehicles push the movement of these idle overhead cranes. However, during the operation of the system, the generation and distribution of tasks are not uniform. This will result in that in the cruising strategy, the idle overhead cranes are often concentrated in certain work areas with a large number of tasks, and in the pushing strategy, when the pushing task overhead crane completes the task, it will also stay in place and stop pushing the previous idle overhead crane, resulting in the accumulation of idle overhead cranes, or because the previous overhead crane has taken the task nearby, the subsequent idle overhead crane cannot go to the task location.

[0032] Moreover, in general, the above solutions for handling idle overhead cranes all ignore the mobility of the idle overhead cranes in the entire system.

[0033] This technical solution is designed for the patrolling of idle overhead cranes, mainly to optimize the mobility of idle overhead cranes in the overall system. After classifying many work areas according to the amount of tasks, setting priorities to allocate idle vehicles, and setting some conditions to drive idle overhead cranes to patrol the entire system. It aims to reduce the time for idle overhead cranes to receive goods, reduce the impact on task overhead cranes, and improve the operating efficiency of the overall system.

[0034] Those skilled in the art will appreciate that, although the material handling system of the semiconductor industry is taken as an example in the embodiments of the present invention, the technical solution of the present invention may also be applicable to similar scenarios requiring material handling in other production fields.

[0035] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0036] Figure 1 Schematic diagram of a material handling system in an embodiment of the present invention. The dynamic idle overhead crane cruising method is used to control and dispatch an overhead crane in a material handling system. Figure 1 As shown in FIG. 1 , the material handling system includes a plurality of work areas (intrabays), and a transport channel (interbay) is arranged in the middle of two groups of work areas. Figure 1 As shown in a(1), a(2), b(1), etc.

[0037] According to the amount of tasks in the work area, the work area is divided into different area categories. Each area category includes at least one work area. The specific number of area categories can be determined according to the number of designed work areas. If the number of work areas is too small, no area category can be set. If the number of work areas is too large, it can be divided into more than two areas. Figure 1 In the , the work area is divided into a-type area and b-type area. The amount of tasks in the work area in the a-type area is more than that in the b-type area. There are 4 work areas in the a-type area and 4 work areas in the b-type area.

[0038] There are idle overhead cranes, cargo-releasing overhead cranes and cargo-receiving overhead cranes in the work area. Of course, during the operation of the system, due to the different cargo-receiving and cargo-releasing states of the overhead cranes, there may be only one or two of the idle overhead cranes, cargo-releasing overhead cranes and cargo-receiving overhead cranes in the work area.

[0039] Figure 2 FIG. 1 is a flow chart of a method for dynamically idling overhead traveling crane in an embodiment of the present invention. Figure 1 , Figure 2 As shown, the number of vehicles in the jth work area is recorded as m j The maximum number of vehicles allowed to exist simultaneously in the work area is The upper limit of potential idle vehicles is The number of potential idle cranes is the sum of the number of idle cranes and the number of cargo-releasing cranes. The maximum number of vehicles and the upper limit of potential idle vehicles in different work zones can be set to different values. The upper limit of the idle crane's stay time in the work zone is T.

[0040] The maximum number of vehicles The maximum number of cranes that can be accommodated in the work area is set based on the track length in the work area and the maximum speed allowed for the crane to travel. It is the initial value set for each area category at the beginning of system operation, and can be adjusted later according to the actual operation situation. The upper limit T of the idle crane's stay time in the work area can also be adjusted according to the subsequent actual operation situation. The purpose of the adjustment is to reduce the average delivery time without affecting the overall average delivery time.

[0041] Furthermore, the potential idle crane limit The adjustment method is:

[0042] Set initial Count the average delivery time of idle cranes in each work area and calculate the variance and mean;

[0043] Increase initial After adjustment Observe the variance and mean;

[0044] When both the variance and the mean decrease, it is determined that the adjusted Better than initial and make it a new

[0045] When both the variance and mean increase, the adjusted Decrease and observe the variance and mean again.

[0046] Further, it is examined whether the work area is smaller due to the shorter delivery time. If the value is too large, the receiving time of the work area with longer receiving time will increase, and individual work areas will be adjusted accordingly.

[0047] Furthermore, the upper limit of the idle crane's stay time in the work area is adjusted to T as follows:

[0048] Set the initial T, count the average delivery time of idle cranes in each work area and calculate the variance and mean;

[0049] Increase the initial T and get the adjusted T, and observe the variance and mean;

[0050] When both the variance and the mean value decrease, the adjusted T is judged to be better than the initial T and is used as the new T;

[0051] When both the variance and mean increase, decrease the adjusted T and observe the variance and mean again.

[0052] Similarly, examine whether the T value of the work area with a shorter receiving time is too large, which leads to an increase in the receiving time of the work area with a longer receiving time, and make adjustments to individual work areas accordingly.

[0053] If there is a parking area in the work area, the idle crane will cruise in the work area for a predetermined time and then wait in the parking area. If there is no parking area in the work area, the idle crane will cruise in the work area for a predetermined time and then stay in the transport channel and can be pushed by other task cranes. Task cranes are receiving cranes and releasing cranes. On this basis, the system executes Figure 2 The dynamic idle crane patrol method shown in the figure. In the process of executing this patrol method, when the idle crane receives a task assignment, such as a cargo pickup task, the task assignment is executed first.

[0054] like Figure 2 As shown, the dynamic idle crane cruising method includes the following steps:

[0055] S0, the system starts running, all overhead cranes enter the track. And set the maximum number of vehicles in each work area Potential idle vehicle limit and the upper limit T of the time that an idle overhead crane stays in the work area.

[0056] S1. When a newly added idle crane is added in a work area, it is determined whether the newly added idle crane is the only potential idle crane in the current work area. Potential idle cranes are idle cranes and cargo cranes. The newly added idle crane is also included in the case where it is designated as a newly added idle crane due to exceeding the restriction conditions in the subsequent steps.

[0057] If the newly added idle crane is the only potential idle crane in the current work area, the newly added idle crane will stay in the current work area and keep the original state. At this time, if a new idle crane or task crane enters the work area, the process goes to step S5. The task crane refers to the receiving crane or the releasing crane.

[0058] If the newly added idle overhead crane is not the only potential idle overhead crane in the current work area, the process proceeds to step S2.

[0059] S2. Determine whether there is a work area without potential idle overhead crane in the system.

[0060] If there is a work area without a potential idle overhead crane in the system, then the work area without a potential idle overhead crane is examined in order of priority from high to low in terms of the task volume of the regional category to which the work area belongs, and the work area with the highest task volume and without a potential idle overhead crane is selected as the target work area. In this embodiment, the work area is divided into a class a area and a class b area according to the task volume from high to low. The task volume of the class a area is greater than that of the class b area. Then, the work area without a potential idle overhead crane is selected as the target work area in the order of first the class a area and then the class b area. The idle overhead crane with the longest stay time in the current work area is used as the mobile idle overhead crane to drive to the target work area, and step S3 is entered.

[0061] If there is no work area without a potential idle overhead travelling crane in the system, the process proceeds to step S8.

[0062] S3. When the mobile idle overhead crane arrives at the entrance of a passing work area during the process of moving toward the target work area, it is determined whether the current passing work area is the target work area.

[0063] If the currently passing work area is the target work area, the idle overhead crane is moved to cruise in the target work area and the process goes to step S5.

[0064] If the current passing work area is not the target work area, go to step S4.

[0065] S4. Determine whether there is a replaceable idle overhead crane with a cruising time exceeding T / 2 in the current passing work area.

[0066] If there is a replaceable idle overhead crane in the current passing work area, the mobile idle overhead crane enters the current passing work area and replaces with the replaceable idle overhead crane. The replaceable idle overhead crane continues to run to the next passing work area as the new mobile idle overhead crane, and determines whether it is the target work area.

[0067] If there is no replaceable idle overhead crane in the current passing work area, the mobile idle overhead crane directly continues to run to the next passing work area, and enters step S3.

[0068] S5. Determine whether the number of potential idle overhead cranes in the target work area is greater than

[0069] If the number of potentially idle cranes in the target work area is greater than Idle cranes outside the target work area are prohibited from entering. Idle cranes outside the current work area are allowed to be replaced with idle cranes in the current work area, and after the cargo delivery crane enters the current work area, the idle crane with the longest cruising time is designated as exceeding the restriction condition state. The crane in the exceeding restriction condition state is regarded as a newly added idle crane, and the process proceeds to step S1.

[0070] If the number of potentially idle cranes in the target work area is not greater than Then proceed to step S6.

[0071] In this paragraph or elsewhere in this text, "not greater than" means less than or equal to. "Greater than" does not include equal to.

[0072] S6: Determine whether the total number of vehicles in the target work area is greater than

[0073] If the total number of vehicles in the target work area is greater than Then determine whether there is an idle overhead crane in the target work area. If there is an idle overhead crane in the target work area, the idle overhead crane with the longest cruising time is designated as an out-of-restriction state. The crane in the out-of-restriction state is regarded as a newly added idle overhead crane, and the process proceeds to step S1. If there is no idle overhead crane in the target work area, the original state is maintained. At this time, if a new idle overhead crane or task overhead crane enters the work area, the process proceeds to step S5.

[0074] If the total number of vehicles in the target work area is not greater than Then go to step S7.

[0075] S7. Determine whether the idle mobile crane stays in the target working area for a time greater than T.

[0076] If the idle mobile crane stays in the target work area for longer than T, the idle mobile crane is designated as exceeding the restriction condition state. The crane in the exceeding restriction condition state is regarded as a newly added idle crane, and the process proceeds to step S1.

[0077] If the idle mobile crane stays in the target work area for no longer than T, the original state is maintained. If a new idle crane or task crane enters the work area, the process proceeds to step S5.

[0078] S8. Determine whether there is an idle overhead crane position in the work area in the category a area.

[0079] If there is an idle crane position in the work area in the A-type area, the mobile idle crane will be assigned to the work area with the least potential idle cranes in the A-type area. If the idle crane positions of all work areas in the A-type area are the same, one of the work areas will be selected nearby.

[0080] If there are no idle overhead crane positions in all work areas in the a-type area, proceed to step S9.

[0081] S9. Determine whether there is an idle overhead crane position in the work area in the Class B area.

[0082] If there is an idle crane position in the work area of ​​the B-type area, the idle crane is assigned to the work area with the least potential idle cranes in the B-type area. If the idle crane positions of all work areas in the B-type area are the same, one of the work areas is selected nearby.

[0083] If there is no idle overhead crane position in all work areas in the b-type area, the original state is maintained. If a new idle overhead crane or a task overhead crane enters the work area, step S5 is entered.

[0084] The above steps S8 and S9 are because in this embodiment, the work area is divided into a class a area and a class b area. Of course, when there are a large number of work areas in the system, there may be more classifications of work areas. At this time, if there is no work area without a potential idle overhead crane in the system, then in step S8 and the steps after S8, it is determined whether there is a work area with an idle overhead crane position in the current highest priority work area category according to the priority order of the task volume from high to low. If there is a work area with an idle overhead crane position in the current highest priority work area category, the work area with the least potential idle overhead crane in the current highest priority work area category is used as the target work area. If the number of potential idle overhead cranes in all work areas is the same, a work area nearby is selected as the target work area. If there is no idle overhead crane position in all work areas in the current highest priority work area category, it is continued to determine whether there is an idle overhead crane position in the work area in the next second highest priority work area category. If there is no work area with an idle overhead crane position in all work area categories, the original state is maintained.

[0085] During the process of executing steps S1 to S9, if an idle overhead crane at any stage receives a task instruction, the process will be terminated and the task instruction will be executed first.

[0086] Figure 2 The flowchart shown is a preferred embodiment of the dynamic idle crane cruising method in this application. In this embodiment, the scheme divides the area categories according to the task volume of different work areas, so that the idle crane can be preferentially allocated to the work area with a large task volume. The maximum number of vehicles in each work area is set. Potential idle vehicle limit and the upper limit T of the idle crane's stay time in the working area to drive the idle crane to dynamically cruise in the entire system.

[0087] During this process, a procedure is also set up to exchange the patrol tasks of the idle overhead cranes in the work area according to time, which further improves the mobility of the idle cranes.

[0088] but Figure 2 The embodiment shown is a preferred embodiment and is not a limitation of the present technology. Those skilled in the art can understand that in actual work, only one embodiment can be implemented as needed. Figure 2 Some of the steps in the above method can also optimize the cruising method of the idle overhead crane to a certain extent relative to the prior art and obtain corresponding technical effects. As long as the implemented steps are relatively complete, logically closed, and can ensure the normal operation of the system.

[0089] For example, in one embodiment, only steps S1, S2 and S3 are used, that is, the area categories are divided according to the task volume of different work areas, so that idle overhead cranes can be preferentially allocated to work areas with large task volumes, thereby improving the operating efficiency of the system to a certain extent.

[0090] For example, in one embodiment, only steps S1 to S5 are used, by setting a potential idle vehicle upper limit By increasing the replacement steps of idle overhead cranes that have been cruising for too long, the mobility of idle overhead cranes can be increased to a certain extent, and the operating efficiency of the system can be improved.

[0091] The technical solution of the present invention will be further described below through a specific embodiment.

[0092] Please combine Figure 1 and Figure 2 .exist Figure 1 There are 8 work areas, which are divided into type A area and type B area according to the amount of tasks. The work areas in each type of area are represented by numbers in brackets. For example, the work areas in type A area include a(1), a(2), a(3), and a(4).

[0093] The initial setting of the upper limit of potential idle vehicles in the a-type area is 2, and the upper limit of potential idle vehicles in the b-type area is 1. Different states of the overhead crane are represented by different colors, yellow is the receiving overhead crane, red is the releasing overhead crane, and blue is the idle overhead crane. In this embodiment, the dynamic idle overhead crane patrol method includes:

[0094] S1a, there is a newly added idle overhead crane OHT8 in the work area b(1), it is determined that the newly added idle overhead crane OHT8 is not the only potential idle overhead crane in the work area b(1), and the process goes to step S2a.

[0095] S2a, determine whether there is a work area b(4) without potential idle overhead cranes in the system, and use the work area b(4) as the target work area. And use the idle overhead crane OHT21 with the longest stay time in the work area b(1) as the mobile idle overhead crane to drive to the target work area b(4).

[0096] S3a, the idle mobile crane OHT21 arrives at the entrance of the work area a(3), and determines that the work area a(3) is not the target work area.

[0097] S4a: It is determined that there is a replaceable idle overhead crane OHT20 with a cruising time exceeding T / 2 in the work area a (3). OHT21 exchanges tasks with OHT20, and OHT20 serves as a new mobile idle overhead crane to go to the work area b (4).

[0098] The technical solution of the present invention will be further described below through another specific embodiment. Figure 1 and Figure 2 In this embodiment, the dynamic idle overhead crane cruising method includes:

[0099] S1b, there is a newly added idle overhead crane OHT24 in the work area b(3), it is determined that the newly added idle overhead crane OHT24 is not the only potential idle overhead crane in the work area b(3), and the process goes to step S2b.

[0100] S2b: Determine whether there is no work area without a potential idle overhead travelling crane in the system. Then, proceed to step S8b.

[0101] S8b: Determine that there is no idle overhead crane position in the category a area, and proceed to step S9b.

[0102] S9b, it is determined that there is no idle overhead crane position in the b-type area, and the original state is maintained, and the overhead crane OHT24 and the overhead crane OHT23 both keep patrolling in the work area b (3). At this time, if a new demand, that is, a task, appears, the task is executed first, and the overhead crane OHT23 with a longer patrol time is assigned to the work area with demand.

[0103] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. The present invention may be modified in any form without violating the basic structure of the present invention.

Claims

1. A dynamic idle overhead crane cruising method, characterized in that: Used in a material handling system, the material handling system includes a plurality of work areas; in the work areas there are idle cranes, cargo-releasing cranes and / or cargo-receiving cranes; the patrol method includes the following steps: When a newly added idle crane is added in a work area, it is determined whether the newly added idle crane is the only potential idle crane in the current work area; the potential idle cranes are idle cranes and cargo cranes; if the newly added idle crane is the only potential idle crane in the current work area, the original state is maintained; If the newly added idle overhead crane is not the only potential idle overhead crane in the current work area, determine whether there is a work area without potential idle overhead cranes in the system; if there is a work area without potential idle overhead cranes in the system, check whether there is a work area without potential idle overhead cranes in order of priority from high to low task volume and select it as the target work area; and make the idle overhead crane that stays the longest in the current work area as the mobile idle overhead crane and drive it to the target work area.

2. The dynamic idle overhead crane cruising method according to claim 1, characterized in that: When the mobile idle overhead crane arrives at the entrance of a passing work area while driving towards the target work area, it is determined whether the current passing work area is the target work area; if the current passing work area is the target work area, the mobile idle overhead crane enters the target work area for patrol; if the current passing work area is not the target work area, it continues to run to the next passing work area and determines whether it is the target work area.

3. The method for cruising a dynamic idle overhead crane according to claim 2, characterized in that: Set the upper limit of the idle crane's stay time in the work area to T; When the mobile idle overhead crane arrives at the entrance of a passing work area, if it is determined that the current passing work area is not the target work area, it is determined whether there is a replaceable idle overhead crane with a patrol time exceeding T / 2 in the current passing work area. If there is a replaceable idle overhead crane with a patrol time exceeding T / 2 in the current passing work area, the mobile idle overhead crane enters the current passing work area and is replaced with the replaceable idle overhead crane. The replaceable idle overhead crane continues to run to the next passing work area as the new mobile idle overhead crane, and determines whether it is the target work area; if there is no replaceable idle overhead crane with a patrol time exceeding T / 2 in the current passing work area, the mobile idle overhead crane continues to run to the next passing work area, and determines whether it is the target work area.

4. The method for cruising a dynamic idle overhead crane according to claim 1, characterized in that: If there is no work area without potential idle overhead crane in the system, it is determined whether there is an idle overhead crane position in the current highest priority work area category in descending order of priority of task volume; If there is a work area with an idle overhead crane position in the current highest priority work area category, the work area with the least idle overhead cranes is selected as the target work area; if there is no work area with an idle overhead crane position in the current highest priority work area category, continue to determine whether the next highest priority work area has an idle overhead crane position; if there are no idle overhead crane positions in the work areas of all work area categories, maintain the original status.

5. The method for cruising a dynamic idle overhead crane according to claim 1, characterized in that: The number of vehicles in the jth work area is denoted as m j , the upper limit of the potential idle crane in the jth work area is After the mobile idle crane enters the target work area and cruises, it is determined whether the number of potential idle cranes in the target work area is greater than If the number of potentially idle cranes in the target work area is greater than Idle overhead cranes outside the target work area are prohibited from entering.

6. The method for cruising a dynamic idle overhead crane according to claim 5, characterized in that: If the number of potentially idle cranes in the target work area is greater than It is allowed that an idle overhead crane outside the current work area can be replaced with an idle overhead crane within the current work area, and after the cargo-releasing overhead crane enters the current work area, the idle overhead crane with the longest cruising time is designated as being in a state of exceeding restrictions; and the crane in a state of exceeding restrictions is designated as a newly added idle overhead crane.

7. The method for cruising a dynamic idle overhead crane according to claim 5, characterized in that: Set the maximum number of vehicles allowed to exist simultaneously in the jth work area to If the number of potentially idle cranes in the target work area is not greater than Then determine whether the total number of vehicles in the target work area is greater than If the total number of vehicles in the target work area is greater than It is determined whether there is an idle overhead crane in the target work area; if there is an idle overhead crane in the target work area, the idle overhead crane with the longest cruising time is designated as an out-of-restriction state; and the crane in the out-of-restriction state is designated as a newly added idle overhead crane; if there is no idle overhead crane in the target work area, the original state is maintained.

8. The method for cruising a dynamic idle overhead crane according to claim 6, characterized in that: Set the upper limit of the idle crane's stay time in the work area to T; if the total number of cranes in the target work area is not greater than It is determined whether the idle overhead crane stays in the target work area for a time greater than T. If so, the idle overhead crane that exceeds the maximum stay time T is designated as being in an out-of-restriction condition state; and the crane in the out-of-restriction condition state is designated as a newly added idle overhead crane.

9. The method for cruising a dynamic idle overhead crane according to any one of claims 1 to 8, characterized in that: In the step of maintaining the original state, if a new idle crane or task crane enters the work area, it is directly determined whether the number of potential idle cranes in the target work area is greater than Determine whether the total number of vehicles in the target work area is greater than And / or a step of judging whether the idle mobile crane stays in the target work area for a time greater than T; the task crane is a receiving crane or a releasing crane.

10. The method for cruising a dynamic idle overhead crane according to any one of claims 3, 5, 7 or 8, characterized in that: The system adjustable parameters can be adjusted to reduce the average pickup time without affecting the overall average delivery time; The adjustable parameter of the system is the upper limit of potential idle crane and the upper limit T of the idle crane's stay time in the work area; the adjustment method is: Set the initial values ​​of the system's adjustable parameters, count the average pick-up time of idle overhead cranes in the work area, and calculate the variance and mean; Increase the initial value and obtain the adjusted value, and observe the variance and mean of the average delivery time; When both the variance and the mean decrease, the adjusted value is judged to be better than the initial value; When both the variance and the mean value increase, the adjusted value is reduced, and the variance and mean value of the average pickup time of the idle overhead cranes in each work area are observed again.

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