A method for real-time calculation of transfer vehicle scheduling tasks

Abstract

The present invention discloses a method for real-time calculation of transfer vehicle scheduling tasks, including: step 1, obtaining and recording on-site information of casting machine production lines; step 2, screening out a pot-changing demand queue, and calculating the remaining time of aluminum liquid for each casting machine production line in the queue; step 3, creating a pot-changing task, and calculating the planned start time of the pot-changing task and the available time of subsequent tasks according to the current time and the remaining time of aluminum liquid, and the planned start time of the subsequent task shall not be less than the available time of the subsequent task. The method of the present invention can accurately calculate a reasonable planned start time of a pot-changing task according to casting machine information. When multiple casting equipment need aluminum liquid at the same time, the pot-changing task in the front row starts pot-changing in advance to ensure that the subsequent equipment does not stop.

Description

Technical Field

[0001] The invention belongs to the field of production lines in the foundry industry, in particular to the fields of casting informatization and casting automation, and specifically relates to a pot changing scheduling method for a molten aluminum transfer trolley in the foundry industry. Background Art

[0002] The materials used in foundries are mainly aluminum ingots. Generally, aluminum ingots are turned into aluminum liquid through a melting furnace. The RGV (rail-guided vehicle) trolley carries the crucible aluminum liquid and sends the crucible filled with aluminum liquid to the degasser. After the degasser treats the aluminum liquid with alloys, it is sent to the casting machine through the RGV trolley. The casting equipment hydraulically casts the aluminum in the crucible into products. Then the empty crucible is sent to the melting furnace through the RGV trolley to be filled with aluminum liquid, and then to the degasser for alloy treatment. After the end, it is sent to the casting machine for die-casting products, and this process is repeated. In the traditional foundry industry, people stand on the RGV trolley and manually operate the trolley. When the hydraulic casting of the crucible aluminum on the casting machine is about to end, the casting machine operator notifies the RGV trolley personnel that the pot needs to be changed. The RGV personnel send the crucible furnace that has been degassed in advance to the die-casting machine station. We call this process "manual pot calling". "Manual pot-changing" has a very big disadvantage: when there are many casting equipment, it is very easy for personnel at two casting stations to call the RGV personnel for pots at the same time. At this time, the RGV personnel can only handle the pot-changing tasks one by one, and equipment downtime is inevitable. Summary of the invention

[0003] In response to the above technical problems, the present invention provides a method for real-time calculation of transfer trolley scheduling tasks, which can accurately calculate a reasonable planned start time for pot changing tasks based on casting machine information. When multiple casting equipment need molten aluminum at the same time, the pot changing tasks in the front can start pot changing in advance to ensure that the subsequent equipment does not stop.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] The present invention discloses a method for real-time calculation of transfer vehicle scheduling tasks, wherein the method comprises the following steps:

[0006] Step 1: Obtain and record the on-site information of the casting machine production line to support the calculation of the subsequent scheduling queue of the molten aluminum transfer vehicle;

[0007] Step 2: Filter out the pot replacement demand queue and calculate the remaining time C of the aluminum liquid of each casting machine production line in the queue;

[0008] Step 3, create a pot-changing task, calculate the planned start time of the pot-changing task and the available time of the subsequent task based on the current time and the remaining time of the aluminum liquid, and the planned start time of the subsequent task must not be less than the available time of the subsequent task.

[0009] Furthermore, the field information can be obtained through the OPC protocol or through the data interface of the existing system. The field information includes: the current casting die, the rated casting die, the die change time, whether there is a subsequent production task; it can also include equipment status, aluminum liquid insulation start time, product model, etc., among which the rated casting die can be a defined constant or a variable collected on site.

[0010] Furthermore, the data interface is requested to obtain the casting machine status information and the latest casting equipment status information is saved; if the casting mold is changed when the currently obtained casting machine status information is compared with the previous status information, the mold change time is recorded.

[0011] Furthermore, the remaining time C (unit: seconds) of the aluminum liquid is calculated using the following formula:

[0012] Remaining time of aluminum liquid = (remaining mold times - 1) * theoretical process cycle + remaining time of current mold times;

[0013] The remaining time of the current module (negative number is 0) = theoretical process cycle - (current time - module change time);

[0014] Remaining mold times = rated casting mold times - current casting mold times.

[0015] Furthermore, in step 2, for the casting machines for which "whether there is a subsequent production task" is set as owned, after calculating the remaining time of the molten aluminum, incremental sorting is performed according to the remaining time of the molten aluminum to obtain a pot replacement demand queue.

[0016] Furthermore, in step 3, the pot changing tasks are sorted in order of the planned start time to form a task queue; the pot changing tasks include the following attributes: casting equipment number; planned start time of the pot changing task; planned pot changing time; and pot changing completion time.

[0017] If the ideal start time is greater than or equal to the available time of the subsequent task, then the planned start time of the pot replacement task = the ideal start time;

[0018] Ideal start time = (current time + remaining time of aluminum liquid) - lead time;

[0019] Lead time = time for RGV trolley to enter the transfer table to exchange crucible + time from transfer table to die casting station;

[0020] otherwise,

[0021] Calculate the required lead time = available time of subsequent tasks - ideal start time;

[0022] Adjust the previous task queue to obtain the task advance time.

[0023] The planned start time of the pot-changing task = the available time of the subsequent task - the task advance time.

[0024] Further, the planned pot replacement time = the planned start time of the pot replacement task + the lead time;

[0025] The pot replacement completion time = the planned pot replacement time + the post - processing time;

[0026] The post - processing time = the crucible replacement time + the time from the transfer station to the die - casting station + the time for the RGV cart to enter the transfer station to exchange the crucible;

[0027] Update the available time of the subsequent tasks to the "pot replacement completion time".

[0028] Further, the method for adjusting the previous task queue is as follows:

[0029] S31, when the task queue [0, n] requires a lead time of T, and the number of tasks in [0, n] is greater than 1, that is, n > 0, calculate the task interval time of n, the lead time of the n - th task, and the remaining lead time of the n - th task;

[0030] The task interval time of n = the start time of the n - th task-(the end time of the (n - 1)-th task);

[0031] The lead time of the task is the difference between the time when the molten aluminum is exhausted and the planned pot replacement time of the current task. If this value is positive, it means the task has been advanced; if this value is negative, it means the task has been delayed;

[0032] The remaining lead time of the task = the maximum lead amount - the lead time of the task;

[0033] S32, calculate the allowable lead time: If the remaining lead time of the task < T, then the allowable lead time takes the remaining lead time of the task; otherwise, take T;

[0034] S33, if the allowable lead time > the task interval time, adjust T = the allowable lead time - the task interval time, the task interval = 0, and calculate recursively:

[0035] If the length of the task queue [0, n] is greater than 2, that is, n > 2, jump the task queue [0, n) and T to step S31;

[0036] If the length of the task queue [0, n] is equal to 2, that is, n = 2, jump the task queue [0, n) and T to step S34;

[0037] If the length of the task queue [0, n] is less than 2, that is, n < 2, jump the task queue [0, n) and T to step S35;

[0038] Obtain the actual lead time of the tasks in the task queue [0, n), and the actual lead time = the actual lead time of the task queue [0, n)+the allowable lead time;

[0039] Otherwise, adjust the task interval time: task interval time = task interval time - T, actual advance time = [0,n) task queue actual advance time + allowed advance time.

[0040] Furthermore, the maximum advance measurement is the number of casting machines*single mold time, which is stored in the database, and the preferred range is 20-30 minutes.

[0041] Further, S34, when the [0,n] task queue needs to be advanced by T, and the [0,n] task is equal to 1, the task interval time between the current task plan start time and the current time and the time allowed to be advanced are calculated;

[0042] If the time allowed to be advanced is greater than T, adjust the interval time: interval time = interval time - time allowed to be advanced, actual advance time = T;

[0043] Otherwise, the actual lead time = T, and the task interval time is adjusted: task interval time = task interval time - actual lead time;

[0044] S35, when the [0,n] task queue needs to be advanced by T, and the [0,n] task is equal to 0, the task has been advanced by 0;

[0045] S36, if the allowed advance time is greater than the task interval time, the current task is advanced by the task interval time; and the task advance time and the task interval time of the first task in the task queue are obtained.

[0046] Furthermore, when the [0,n]th task queue needs to obtain the task advance time, the number of [0,n] tasks is greater than 1, if task n has been postponed, the task advance time is 0; if the task n has been advanced more than the set maximum advance amount, the task can be advanced to 0.

[0047] Queue adjustment (pot change queue, advance time, maximum advance amount)

[0048] {

[0049] Queue length = pot-changing queue.length

[0050] If queue length > 1:

[0051] Task interval = pot-changing queue [queue length - 1]. Planned start time - pot-changing queue [queue length - 2]. Planned start time

[0052] Task advance time = pot change queue [queue length - 1]. aluminum liquid exhaustion time - pot change queue [queue length - 1]. expected pot change time

[0053] The time that the task can be advanced = the maximum advance time - the time the task has been advanced

[0054] The time allowed to be advanced = the time that the task can be advanced < the time to be advanced? The time that the task can be advanced: the time to be advanced

[0055] If the task has advanced time < 0:

[0056] Return 0

[0057] Or the time that the task can be advanced is <= 0:

[0058] Return 0

[0059] otherwise:

[0060] If the time allowed to advance is greater than the task interval:

[0061] Previous task queue = pot-changing queue.Take (pot-changing queue.length-1)

[0062] Task lead time = queue adjustment (previous task queue, allowed lead time - task interval, maximum lead time) + task interval

[0063] Pot-changing queue [queue length - 1]. Task planning time = Pot-changing queue [queue length - 1]. Task planning time - Task advance time

[0064] Pot changing queue [queue length - 1]. Estimated pot changing time = pot changing queue [queue length - 1].

[0065] Estimated pot replacement time-task lead time

[0066] Return task lead time

[0067] otherwise:

[0068] Pot-changing queue [queue length - 1]. Task plan time = Pot-changing queue [queue length - 1]. Task plan time - Time allowed to advance

[0069] Pot changing queue [queue length - 1]. Estimated pot changing time = pot changing queue [queue length - 1].

[0070] Estimated pot change time - time allowed in advance

[0071] Returns the time allowed to advance

[0072] Or queue length = 1:

[0073] Task interval time = pot change queue [0]. Planned start time - current time

[0074] Task advance time = pot change queue [0]. aluminum liquid exhaustion time - pot change queue [0]. expected pot change time

[0075] The time that the task can be advanced = the maximum advance time - the time the task has been advanced

[0076] The time allowed to be advanced = the time that the task can be advanced < the time to be advanced? The time that the task can be advanced: the time to be advanced

[0077] If the time allowed to advance is greater than the task interval:

[0078] Pot-changing queue [0]. Task planning time = Pot-changing queue [0] - Task interval time

[0079] Returns the task interval time

[0080] otherwise:

[0081] Pot-changing queue [0]. Task plan time = Pot-changing queue [0] - allowed advance time

[0082] Returns the time allowed to advance

[0083] }

[0084] Beneficial effects: The general production process of an aluminum foundry can be divided into three processes: "receiving molten aluminum", "alloying molten aluminum", and "changing pots (casting)". These three processes are executed sequentially to form a closed loop. The start time and work efficiency of each process will affect the next process, thereby affecting the entire production system. For example, the next process of alloy treatment is changing pots (casting). If the actual efficiency of alloy treatment is low, it will cause periodic shutdown of casting. The previous process of alloy treatment is receiving liquid, and the frequency of receiving liquid is affected by the pot changing task. The present invention can adjust the entire casting system by adjusting the start time of the pot changing task, effectively utilize the performance of the equipment, and increase the fault tolerance of the entire casting system. According to the real-time information on site, the principle of "maximizing the use of RGV trolley capacity, consuming aluminum liquid as fully as possible, and ensuring that CPC does not stop and the stopped equipment does not participate in the calculation" is met, and the "pot changing scheduling algorithm" is used to calculate the most reasonable task queue. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 Schematic diagram of a single pot changing task cycle according to an embodiment of the present invention.

[0086] Figure 2 The remaining time of the aluminum liquid in the embodiments of the present invention is sorted.

[0087] Figure 3 The figure is a schematic diagram of a process of generating a task queue according to the remaining time of aluminum liquid according to an embodiment of the present invention.

[0088] Figure 4 Schematic diagram of the final pot-changing queue according to an embodiment of the present invention. DETAILED DESCRIPTION

[0089] To facilitate understanding by those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings.

[0090] In view of the low production efficiency caused by manual operation of RGV trolleys, the RGV trolley scheduling system suitable for the foundry industry can control each trolley to complete a series of instructions in real time according to the current production situation, improve the operation efficiency of the trolley, shorten the material replacement time, reduce the idle time of the equipment, and greatly reduce the personnel cost, avoiding the risk caused by human operation errors. The production line of this embodiment must contain more than or equal to 2 casting equipment, and be equipped with a transfer table for placing aluminum crucibles and an RGV trolley for replacing aluminum crucibles.

[0091] The site has an interface for providing production line information, and the on-site information includes: "Casting equipment status", "Whether the casting equipment has subsequent tasks", "Current mold of the casting equipment", "Rated mold of the casting equipment", and "Product model".

[0092] The site must be equipped with a database and store the benchmark configuration of "RGV action time" and "theoretical process beat" of the product. "RGV action time" includes: T1 = RGV trolley enters the transfer table to exchange crucible + transfer table to die casting station time, T2 = crucible replacement time, T3 = transfer table to die casting station time + RGV trolley enters the transfer table to exchange crucible time. Lead time = T1, post time = T2 + T3. Figure 1 shown.

[0093] Obtain the base configuration of the database according to the casting equipment number and calculate the pot replacement cycle, which includes:

[0094] Lead time = time for RGV trolley to enter the transfer table to exchange crucible + time from transfer table to die casting station;

[0095] Post-processing time = crucible replacement time + time from transfer table to die-casting station + time for RGV trolley to enter transfer table to exchange crucible.

[0096] In the method of adjusting the previous task queue, the pot-changing task is abstracted, and the entire pot-changing task is divided into lead time and post-time, such as Figure 1 .

[0097] The data sources for the pot-changing task scheduling calculation are divided into two parts:

[0098] 1. On-site casting information, including: a. Casting equipment status; b. Whether the casting equipment has subsequent tasks; c. Current mold of the casting equipment; d. Rated mold of the casting equipment; e. Product model.

[0099] 2. Basic configuration in the database, including: a. Theoretical process cycle; b. RGV trolley action time.

[0100] Step A: Obtain on-site information of the production line and record it. Specifically include:

[0101] Request the data interface to obtain the casting machine status information and save the latest casting equipment status information. If the casting mold is changed when comparing the current casting machine status information with the previous status information, record the mold change time.

[0102] Step B: Generate an aluminum liquid demand queue based on the "aluminum liquid remaining time" and "whether there is a subsequent casting task" of the casting machine.

[0103] Step B1: Calculate the remaining time for the aluminum liquid to be consumed according to the remaining molds and mold change time of the casting equipment (unit: seconds) as "aluminum liquid remaining time", and the formula is:

[0104] Aluminum liquid remaining time = (remaining mold times - 1) * theoretical process cycle + current mold remaining time

[0105] The remaining time of the current module (negative number is 0) = theoretical process cycle - (current time - module change time)

[0106] Remaining mold times = rated casting mold times - current casting mold times;

[0107] Step B2: Filter out casting equipment that needs subsequent aluminum liquid according to the following conditions, which is recorded as the "aluminum liquid demand queue":

[0108] Casting equipment status = normal;

[0109] Does it have a follow-up task = yes;

[0110] Step B3: Incrementally sort the "molten aluminum demand queue" obtained in step B2 according to the "molten aluminum remaining time" of the casting equipment.

[0111] Step C: Calculate the pot-changing queue based on the departure time and completion time of the tasks in the scheduling queue.

[0112] Step C1: Circulate the "aluminum liquid demand queue" and calculate the expected task planning time according to the "aluminum liquid remaining time" and the "RGV action time" configured in the database, which is recorded as the "expected start time".

[0113] The formula for calculating the expected start time is as follows:

[0114] Expected start time = current time + remaining time of aluminum liquid - task lead time;

[0115] Task lead time = time to get the crucible from the transfer table + time from the transfer table to each casting machine;

[0116] Step C2:

[0117] According to the "expected start time" calculated in step C1, the task plans are sequentially placed into the task queue, and the theoretical end time of the task is calculated. If the end time of the previous task is greater than the expected start time, the "adjust queue" algorithm is called to obtain the queue advance time, and finally the "planned start time" is calculated. Otherwise, the expected start time is used as the task planned start time.

[0118] According to the following formula, the remaining amount of aluminum liquid can be calculated and sorted, and we can get Figure 2 .

[0119] Remaining time of aluminum liquid = (remaining mold times - 1) * theoretical process cycle + remaining time of current mold times;

[0120] The remaining time of the current module (negative number is 0) = theoretical process cycle - (current time - module change time).

[0121] The pot-changing task is generated based on the remaining time of the aluminum liquid and the trolley action time in the database and inserted into the pot-changing queue. If the aluminum liquid consumption time interval of multiple casting stations is short (the aluminum liquid interval between two stations is less than the task post-time of station A + the aluminum liquid lead-time of station B), the queue is adjusted and the task is inserted into the queue again. The process is as follows Figure 3 .

[0122] The above process is a calculation cycle, and a scheduling queue (such as Figure 4 ), the scheduling algorithm is executed regularly to continuously update the scheduling queue and provide data support for the automatic scheduling system.

[0123] Specific calculation case:

[0124] Set the current time to 10:00:00 and the maximum advance time to 1200 seconds

[0125] The benchmark task times of low-pressure casting equipment are:

[0126] #1 Lead time 540 seconds Post time 540 seconds

[0127] #2 Lead time 510 seconds Post time 510 seconds

[0128] #3 Lead time 480 seconds Post time 480 seconds

[0129] #4 Lead time 450 seconds Post time 450 seconds

[0130] #5 Lead time 420 seconds Post time 420 seconds

[0131] #6 Lead time 390 seconds Post time 390 seconds

[0132] #7 Lead time 360 ​​seconds Post time 360 ​​seconds

[0133] The first step is to obtain the field data as follows:

[0134] #1 Rated mold times = 30 Production mold times = 12 Current mold production time (S) = 60 Equipment status = OK Whether to change mold = N Whether there is a follow-up task = Y

[0135] #2 Rated mold times = 30 Production mold times = 25 Current mold production time (S) = 0 Equipment status = OK Whether to change mold = N Whether there is a follow-up task = Y

[0136] #3 Rated mold times = 30 Production mold times = 0 Current mold production time (S) = 0 Equipment status = OK Whether to change mold = N Whether there is a follow-up task = Y

[0137] #4 Rated mold times = 30 Production mold times = 7 Current mold production time (S) = 120 Equipment status = OK Whether to change mold = N Whether there is a follow-up task = Y

[0138] #5 Rated mold times = 30 Production mold times = 13 Current mold production time (S) = 60 Equipment status = OK Whether to change mold = N Whether there is a follow-up task = Y

[0139] #6 Rated mold times = 30 Production mold times = 8 Current mold production time (S) = 60 Equipment status = OK Whether to change mold = N Whether there is a follow-up task = Y

[0140] #7 Rated mold times = 30 Production mold times = 10 Current mold production time (S) = 120 Equipment status = OK Whether to change mold = N Whether there is a follow-up task = Y

[0141] The second step is to filter out the pot change demand queue and calculate the remaining time of aluminum liquid for each casting machine production line in the queue (such as Figure 2 )

[0142] #2 Time for aluminum liquid to be exhausted (seconds) = 1200 Time for aluminum liquid to be exhausted = 10:20:00 Planned start time = 10:11:30

[0143] #1 Time for aluminum liquid to be exhausted (seconds) = 2700 Time for aluminum liquid to be exhausted = 10:45:00 Planned start time = 10:36:00

[0144] #5 Time for aluminum liquid to be exhausted (seconds) = 3900 Time for aluminum liquid to be exhausted = 11:05:00 Planned start time = 10:58:00

[0145] #7 Time for aluminum liquid to be exhausted (seconds) = 4080 Time for aluminum liquid to be exhausted = 11:08:00 Planned start time = 11:12:00

[0146] #6 Time to exhaust aluminum liquid (seconds) = 5100 Time to exhaust aluminum liquid = 11:25:00 Planned start time = 11:18:30

[0147] #4 Time for aluminum liquid to be exhausted (seconds) = 6600 Time for aluminum liquid to be exhausted = 11:50:00 Planned start time = 11:42:30

[0148] #3 Time for aluminum liquid to be exhausted (seconds) = 7200 Time for aluminum liquid to be exhausted = 12:00:00 Planned start time = 11:52:00

[0149] The pot-changing queue is calculated based on the departure time and completion time of the tasks in the scheduling queue.

[0150] Declare global variables: Subsequent task available time = current time = 10:00;

[0151] 1) Calculated according to "task planning time = current time + aluminum liquid remaining time - task lead time":

[0152] #2. Task planning time = 10:00 (current time) + 1200 (remaining time of aluminum liquid) - 510 (task lead time) = 10:11:30

[0153] #2. Interval time = #2. Task planning time - 10:00 (available time for subsequent tasks) = 690 seconds = 11.5 minutes

[0154] #2. Planned pot change time = aluminum liquid exhaustion time = 10 hours and 20 minutes

[0155] Subsequent task available time = #2. Task end time = aluminum liquid exhaustion time + post-time = 10:20 + 510 = 10:28:30

[0156] 2) If the task interval is greater than or equal to 0, put the task into the queue.

[0157] Substitute #2, #1, and #5 into the calculation in turn, and the pot change queue is as follows:

[0158] #2 Aluminum liquid exhaustion time = 10:20:00 Estimated pot change time = 10:20:00 Task planning time = 10:11:30 Task interval (seconds) = 690 Task completion time = 10:28:30

[0159] #1 Aluminum liquid exhaustion time = 10:45:00 Estimated pot change time = 10:45:00 Task planning time = 10:36:00 Task interval (seconds) = 450 Task completion time = 10:54:00

[0160] #5 Aluminum liquid exhaustion time = 11:05:00 Estimated pot change time = 11:05:00 Task planning time = 10:58:30 Task interval (seconds) = 240 Task completion time = 11:12:00

[0161] Subsequent task available time = #5. Task completion time = 11:12:00

[0162] 3) Substitute #7 into the above calculation.

[0163] #7. Task plan time = 11:08:00 + 4080 (seconds) - 360 (seconds) = 11:02:00

[0164] #7. Interval time = #7. Task planning time - 11:12:00 (available time for subsequent tasks) = -600 seconds = -10 minutes

[0165] 4) If the interval time is less than 0, the queue is adjusted using the recursive algorithm for queue adjustment.

[0166] Queue advance time = queue adjustment (pot change queue, - interval time, maximum advance amount)

[0167] First call, parameters (pot change queue = [#2, #1, #5], time to advance = 600 seconds, maximum advance = 1200 seconds)

[0168] Queue length = 3

[0169] The last element of the queue = the pot-changing queue [queue length - 1] = #5

[0170] Task advanced time = #5. Aluminum liquid exhaustion time - #5. Estimated pot change time = 11:05:00 - 11:05:00 = 0

[0171] The time that the task can be advanced = maximum advance time - the time the task has been advanced = 1200-0 = 1200

[0172] The time allowed to be advanced = the minimum value (the time the task can be advanced, the time to be advanced) = 600

[0173] The amount that needs to be advanced = the time allowed for advancement - #5. Task interval time = 600-240 = 360

[0174] Previous task queue = [#2,#1]

[0175] Task lead time = queue adjustment (previous task queue, allowed lead time - task interval, maximum lead time) + task interval

[0176] Second call, parameters (pot change queue = [#2, #1], advance time = 360 seconds, maximum advance time = 1200 seconds)

[0177] Queue length = 2

[0178] The last element of the queue = the pot-changing queue [queue length - 1] = #1

[0179] Task advanced time = #1. Aluminum liquid exhaustion time - #1. Estimated pot change time = 10:45:00 - 10:45:00 = 0

[0180] The time that the task can be advanced = maximum advance time - the time the task has been advanced = 1200-0 = 1200

[0181] The time allowed to be advanced = the minimum value (the time the task can be advanced, the time to be advanced) = 360

[0182] #1. Task plan time = #1. Task plan time - allowed time to be advanced = 10:39:00 - 360 = 10:30:00

[0183] #1. Estimated pot-changing time = #1. Estimated pot-changing time - allowed advance time = 10:45:00 - 360 = 10:39:00

[0184] #1. Task completion time = #1. Task completion time - allowed time to be advanced = 10:54:00 - 360 = 10:48:00

[0185] Return to 360

[0186] Task lead time = 360 + 240 = 600

[0187] #5.Task plan time = #5.Task plan time - Task advance time = 10:58:30 = 10:48:00

[0188] #5. Estimated pot replacement time = #5. Estimated pot replacement time - task lead time = 11:05:00 - 600 = 10:55:00

[0189] #5. Task completion time = #5. Task completion time - Task advance time = 11:12:00 - 600 = 11:02:00

[0190] Return 600

[0191] Queue Advance Time = 600

[0192] Subsequent task available time = Subsequent task available time - Queue advance time = 11:12:00 - 600 = 11:02:00

[0193] #7. Task plan time = subsequent task available time = 11:02:00

[0194] #7. Estimated time to change the pot = available time for subsequent tasks + lead time = 11:02:00 + 360 = 11:08:00

[0195] Put #7 into the task:

[0196] #2 Aluminum liquid exhaustion time = 10:20:00 Estimated pot change time = 10:20:00 Task planning time = 10:11:30 Task interval (seconds) = 690 Task completion time = 10:28:30

[0197] #1 Aluminum liquid exhaustion time = 10:45:00 Estimated pot change time = 10:39:00 Task planning time = 10:30:00 Task interval (seconds) = 90 Task completion time = 10:48:00

[0198] #5 Aluminum liquid exhaustion time = 11:05:00 Estimated pot change time = 10:55:00 Task planning time = 10:48:30 Task interval (seconds) = 0 Task completion time = 11:02:00

[0199] #7 Aluminum liquid exhaustion time = 11:02:00 Estimated pot change time = 11:08:00 Task planning time = 11:02:00 Task interval (seconds) = 0 Task completion time = 11:14:00

[0200] Subsequent task available time = #7. Task completion time = #7. Estimated pot change time + post-time = 11:08:00 + 360 = 11:14:00

[0201] Substitute #6, #4, and #3 into the calculation in turn, and the final pot change queue is as follows:

[0202] #2 Aluminum liquid exhaustion time = 10:20:00 Estimated pot change time = 10:20:00 Task planning time = 10:11:30 Task interval (seconds) = 690 Task completion time = 10:28:30

[0203] #1 Aluminum liquid exhaustion time = 10:45:00 Estimated pot change time = 10:39:00 Task planning time = 10:30:00 Task interval (seconds) = 90 Task completion time = 10:48:00

[0204] #5 Aluminum liquid exhaustion time = 11:05:00 Estimated pot change time = 10:55:00 Task planning time = 10:48:30 Task interval (seconds) = 0 Task completion time = 11:02:00

[0205] #7 Aluminum liquid exhaustion time = 11:02:00 Estimated pot change time = 11:08:00 Task planning time = 11:02:00 Task interval (seconds) = 0 Task completion time = 11:14:00

[0206] #6 Aluminum liquid exhaustion time = 11:08:00 Estimated pot change time = 11:25:00 Task planning time = 11:18:30 Task interval (seconds) = 270 Task completion time = 11:31:30

[0207] #4 Aluminum liquid exhaustion time = 11:25:00 Estimated pot change time = 11:44:30 Task planning time = 11:37:00 Task interval (seconds) = 330 Task completion time = 11:52:00

[0208] #3 Aluminum liquid exhaustion time = 12:00:00 Estimated pot change time = 12:00:00 Task planning time = 11:52:00 Task interval (seconds) = 0 Task completion time = 12:08:00

[0209] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for real-time calculation of transfer vehicle scheduling tasks, It is characterized in that The following steps are involved: Step 1, obtain on-site information of the casting machine production line and record it; Field information is obtained through the OPC protocol or through the data interface of the existing system; On-site information includes: current casting mold, rated casting mold, and whether there are subsequent production tasks; Request the data interface to obtain the casting machine status information and save the latest casting equipment status information; if the casting mold is changed when comparing the current casting machine status information with the previous status information, record the mold change time; Step 2: Filter out the pot replacement demand queue and calculate the remaining time of aluminum liquid for each casting machine production line in the queue; The method for calculating the remaining time of aluminum liquid is: The remaining time of aluminum liquid = (remaining mold times - 1) * theoretical process cycle + the remaining time of the current mold time; The remaining time of the current mold = theoretical process cycle - (current time - mold change time); Remaining mold times = rated casting mold times - current casting mold times; When the remaining time of the current module is negative, it is set to 0; For the casting machines whose "Whether there is a subsequent production task" is "yes", after calculating the remaining time of the aluminum liquid, the incremental sorting is performed according to the remaining time of the aluminum liquid to obtain the pot replacement demand queue; Step 3, create a pot-changing task, calculate the planned start time of the pot-changing task and the available time of the subsequent task according to the current time and the remaining time of the aluminum liquid, and the planned start time of the subsequent task shall not be less than the available time of the subsequent task; the pot-changing tasks are sorted in the order of the planned start time to form a task queue; the pot-changing task includes the following attributes: casting equipment number; planned start time of the pot-changing task; planned pot-changing time; pot-changing completion time; If the ideal start time >= the available time of the subsequent task, then the planned start time of the pot-changing task = the ideal start time; Ideal start time = (current time + remaining time of aluminum liquid) - lead time; Lead time = time for RGV trolley to enter the transfer table to exchange crucible + time for transfer table to die casting station; Otherwise, calculate the required advance time = the available time of the subsequent task - the ideal start time; adjust the previous task queue to obtain the task advance time; The planned start time of the pot replacement task = the available time of the subsequent task - the task advance time; Planned pot-changing time = planned pot-changing task start time + lead time; Pot replacement completion time = planned pot replacement time + post-time; Post-time = crucible replacement time + time from transfer table to die casting station + time for RGV trolley to enter transfer table to exchange crucible; Update the available time for subsequent tasks to the time when the pot change is completed; The method to adjust the previous task queue is: S31, when the [0,n] task queue needs to be advanced by T, and the number of [0,n] tasks is greater than 1, that is, n is greater than 0, calculate the interval time of n tasks, the time that n tasks have been advanced, and the time that n tasks can be advanced; The interval time between tasks of n = the start time of tasks of n - (the end time of tasks of n-1); The task advance time is the difference between the aluminum liquid exhaustion time and the planned pot change time of the current task. If this value is a positive number, it means that the task has been advanced. If this value is a negative number, it means that the task has been delayed. Time by which the task can be advanced = Maximum advance - Time by which the task has been advanced; The maximum advance is the number of casting machines * Time per single mold cycle; S32. Calculate the allowable time to advance: If the time by which the task can be advanced < T, then the allowable time to advance is the time by which the task can be advanced; otherwise, take T; S33. If the allowable time to advance > Task interval time, adjust T = Allowable time to advance - Task interval time, Task interval = 0, and perform recursive calculation: If the task length of [0, n] is greater than 2, i.e., n > 2, jump the task queue [0, n) and T to step S31; If the task length of [0, n] is equal to 2, i.e., n = 2, jump the task queue [0, n) and T to step S34; If the task length of [0, n] is less than 2, i.e., n < 2, jump the task queue [0, n) and T to step S35; Obtain the actual advance time of the tasks in the [0, n) task queue. The actual advance time = Actual advance time of the [0, n) task queue + Allowable time to advance; Otherwise, adjust the task interval time: Task interval time = Task interval time - T, and the actual advance time = Actual advance time of the [0, n) task queue + Allowable time to advance; S34. When the [0, n] task queue requires an advance time of T and the [0, n] task is equal to 1, calculate the task interval time and the allowable time to advance between the current task planned start time and the current time; If the allowable time to advance > T, adjust the interval time: Interval time = Interval time - Allowable time to advance, and the actual advance time = T; Otherwise, the actual advance time = T, and adjust the task interval time: Task interval time = Task interval time - Actual advance time; S35. When the [0, n] task queue requires an advance time of T and the [0, n] task is equal to 0, then the time by which the task has been advanced is 0; S36. If the allowable time to advance > Task interval time, then advance the current task by the task interval time and obtain the task advance time of the first task in the task queue as the task interval time; When the [0, n] task queue needs to obtain the task advance time and the number of tasks in [0, n] is greater than 1, if the nth task has been postponed, then the time by which the task has been advanced is 0; if the time by which the nth task has been advanced is greater than the set maximum advance, then set the time by which the task can be advanced to 0.

Images