CN101786576A - Critical path method for starting number of portal cranes in container yard - Google Patents

Abstract

A method for coordinating the starting quantity of gantry cranes in a container terminal yard relates to the technical fields of terminal management and yard management. This method uses the berthing plan and stowage plan to decompose the ship loading and unloading tasks into parallel task operation lines, then to the Bay position sequence, and then to the Bay position container loading and unloading task sequence; Card start time and gantry crane start time; after discretizing the time, the number of parallel yard container loading and unloading tasks for any event is calculated in reverse, and after being attributed to Bay bits and continuous Bay bit clusters, the number of parallel job gantry cranes at any time is inferred, and further Estimate the number of gantry crane starts based on statistical criteria. The method does not involve complex models and algorithms, and can be adapted to the prediction of the starting quantity of gantry cranes in large wharves, which is conducive to realizing the goal of energy saving and fully utilizing bridge cranes and gantry cranes.

Description

An overall planning method for the starting quantity of gantry cranes in container terminal yard

technical field

The invention relates to the technical field of management of container terminal yards, in particular to the technical field of starting quantity configuration of gantry cranes in container terminal yards.

Background technique

Container terminals generally formulate berthing plans with a gradually narrowing cycle and accurate ship berthing plans based on the ship's arrival time and operating data, such as berthing plans 4 days, 2 days and 1 day in advance respectively. Generally, the 24-hour berthing plan is very accurate, and related operating resources can be arranged accordingly, including bridge cranes, trucks, gantry cranes, and related operating personnel. From the perspective of equipment configuration, the costs of bridge cranes, trucks and gantry cranes are very different, and the costs of the three are decreasing rapidly in turn. Therefore, in the process of wharf operations, the full utilization of bridge cranes is emphasized to improve the operating efficiency of bridge cranes, followed by gantry cranes, and it is generally assumed that trucks can always meet the requirements. The number of start-up gantry cranes has a lot to do with the distribution of operations. Generally, the terminal itself will be equipped with a certain number of gantry cranes, and the number of gantry cranes is difficult to quickly deploy through leasing and other means. Moreover, idle gantry cranes after start-up will cause waste of resources such as electricity. Therefore, how to determine the number of gantry cranes required in a day and night berthing plan is an important issue about energy saving and consumption reduction.

At present, there is no special research and published patent results for the number configuration of gantry cranes for day and night planning. In the actual stowage, the port planners determine the allocation of gantry cranes to bridge cranes or ship operations based on experience, and do not clearly determine the overall quantity.

The research results that have been made public are mainly research on the assignment and routing of gantry cranes: 1) literature {W.Li, Y.WU, M.E.H.Petering, M.Goh, R.d.SoUza, Discrete time model and algorithms for container yard craneschedUling.EUropean JoUrnal of Operational Research, 2009.198(1): 165-172.}, literature {W.C.Ng, K.L.Mak, Yard craneschedUling in port container terminals.Applied MathematicalModelling, 2005.29(3):263-276.} and literature {Wei Zhong, Shen Jinsheng, Xiao Rongna, Zhang Zhiwen, Shi Dinghuan, Research on Optimal Scheduling of Rubber-tyred Gantry Cranes in Port Container Terminals. China Engineering Science, 2007.9(8): 47-51.}, research on various gantry cranes, research on optimization schemes aimed at improving the performance of gantry cranes ; 2) Literature {Han Xiaolong, Quantity Configuration of Gantry Cranes in Container Port Loading and Unloading. System Engineering, 2005.23(10): 12-16.} and Literature {Han Xiaolong, Ding Yizhong, Research on Configuration Optimization of Container Port Gantry Cranes. China Navigation, 2008.31( 1): 6-9.} discloses a method for determining the allocation of gantry cranes to the task sequence through network flow when the container loading and unloading task sequence is determined. The results disclosed above do not determine the starting quantity of the gantry crane corresponding to the day and night plan or a certain time period as a whole. Although the methods disclosed in some results can be used to calculate the quantity theoretically through transformation, the complexity of the calculation increases exponentially due to the increase in the number of container loading and unloading tasks, and it is difficult to promote in practical applications.

On the other hand, in container ports, there is a general rule when export containers enter the market, that is, the export containers of the same ship should be placed in a certain continuous Bay segment at the front of the wharf, or several such Bay segments , the closer the ship is to this area, the more it can reduce the operating cost of the port and improve the operating efficiency of the ship.

Contents of the invention

The purpose of the present invention is to provide a method for quickly calculating the starting quantity of gantry cranes according to the berthing plan and the stowage plan.

1. Assumptions

In view of the complexity of export shipment, the present invention aims at the configuration of the number of gantry cranes during shipment, and the method of the present invention can adapt to import unloading through simple conversion, or perfect the above two mixed situations.

According to the berthing plan of the container ship, the ship's berthing time and expected departure time can be determined. Then, in the stowage plan, the mapping relationship between the container's bay and the yard's bay is established. The stowage plan arranges the allocation of resources such as bridge cranes, trucks, and gantry cranes. Generally, because bridge cranes are expensive, it is assumed that bridge cranes are fully utilized; then gantry cranes are assumed to be fully utilized; and trucks are considered sufficient. For each ship, according to the number of operating lines assigned to it, the Bay of the entire ship can be divided into continuous sections, and each large section corresponds to an operating line, or a bridge crane. The workload and time of the operation line are based on the operation efficiency of the bridge crane, and it is assumed that the berthing plan has been balanced as much as possible. Obviously, these lines of work are parallelized. The operation line is the operation sequence of the bay position. Generally, in order to avoid the time caused by the back and forth movement of the bridge crane, the bay position is used as the operation unit, that is, the operation of one bay position is completed before moving to the next bay position. In the same bay, it is assumed that the stowage planning department requires container unloading; and, during the yard operation process, there is no container unloading.

2. Definition

The ship, time, yard, operation line, task, bridge crane movement time and single box operation time are defined below.

SHIP＝{1, 2,..., NS}: A collection of ships, s∈SHIP represents one of them (1)

Boat

TIME={1, 2, ..., NT}: Discrete time set, t∈TIME means (2)

A ship may not be an integer, discrete

The interval of optimization is TINT

BLOCK={1, 2, ..., NB}: A collection of storage yards, b∈BLOCK represents a storage yard (3)

SLINE _s = {1, 2, ..., NSL}: set of operation lines of ship s∈SHIP (4)

SLTASK _{s, l} = {1, 2, ...}: Ship s ∈ SHIP's operating line l ∈ SLINE _s (5)

job set, k∈SLTASK _s , l represents the

A job task corresponds to a job task

                                                            

SLTBLOCK, TSBAY, TSROW,

TSLAYER, TYBAY, TYROW,

                                                                         

Yards, Vessels, Lines, Ships and Yards

The Bay position and the row and number of the Bay position

layer. And, these attributes all use the above names

It is called the collection of directly defined values (in the form of

= {1, 2, ..., |·|}).

QCMT _{s, l} : bridge crane (l∈TSLINE(s)) in adjacent Bay(6)

Time to move bits

QCTT _{s, l} : Crane (l ∈ TSLINE (s)) work per container (7)

business hours

In the above definition, the ship loading and unloading task is roughly divided into multiple operation lines, and the Bay position operation sequence is obtained for each operation line, and the assembly line operation sequence is obtained for each Bay position. Then define the movement sequence of the bridge crane, and constrain the matching truck and field crane in order to make full use of the bridge crane.

On the basis of the above definition, define the following predicates to represent the time involved.

SLTStart(s, l, t): Ship loading and unloading container task start event (8)

SLTEnd(s, l, t): Completion time of ship loading and unloading containers, assuming no (9)

There is an unboxing, obviously

SLTEnd(s,l,t)=SLTStart(s,l,t)+QCTT _s,l

TRUCKTStart(s, l, t): TRUCKT container task start event (10)

YCTStart(s, l, t): gantry crane task start event (11)

TRUCKT(s, l, y, yb): Trucks from the operation line l of the ship s to the yard y (12)

The moving time between Bay bit yb

TYC(y1, yb1, y2, yb2): The storage yard gantry crane is in two different bay positions (13)

Movement time between

The following are additional definitions introduced for calculating the number configuration of gantry cranes.

Seq(s, l): one of the tasks of the operation line l of the ship s (14)

sequence, i.e. SLTASK _{s, one of the elements in l}

Replacement

SLTStart(s, l, task): (15) of the task task of the operation line l of the ship s

                                   

TRUCKTStart(s, l, tast): (16) of the task task of the operation line l of the ship s

                          Start time

YCTStart(s, l, task): (17) of the task task of the operation line l of the ship s

                                            

YBAYTIME(blk, yb, tk, t): belongs to {0, 1}, the element represents the storage yard blk (18)

Whether Bay bit yb starts task tk at time t

YBAYTIME(blk, yb, t): The element indicates that the Bay position yb of the yard blk is in (19)

The number of tasks at time t

QCYTQ(blk, t): The number of gantry cranes in the storage yard blk at time t (20)

QCTQ(t): The total number of gantry cranes required at any time t (21)

quantity

QCQ: Estimated number of gantry cranes (22)

The above definition shows that the method disclosed in the present invention sequentially calculates the start time of the bridge crane task, the start time of the collection truck task, and the start time of the gantry crane task according to the task sequence. After discretizing the time, the task and Bay position of each time are calculated in turn , Yard, etc. The task sequence is determined according to the berthing plan and the stowage plan.

2. Calculation process

Different job lines are parallel. A job line is composed of a job sequence, and each job is completed with the loading/unloading of a container. Define Seq(s, l) as a sequence of tasks of operation line l of ship s, that is, a permutation of elements in SLTASK _{s, l} . Define Seq(s, l, i) to take the ith element in the sequence. For a sequence to make full use of the bridge crane, the following conditions should be met.

1) The bridge crane operates in units of bays, that is, to avoid moving back and forth between bays. The condition is as in formula (23):

$\mathrm{<span\; class="notranslate">\; ia</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; ib</span>}<span\; class="notranslate">\; \&DoubleRightArrow;</span>\mathrm{<span\; class="notranslate">\; TSBAY</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Seq</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; ia</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; TSBAY</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Seq</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; ib</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}<span\; class="notranslate">\; )</span>$

2) Containers are not overturned between operations in the same Bay, that is, the loading sequence of the containers in the same Bay meets the requirement that the lower layer (smaller number) is loaded first, and this condition is shown in formula (24):

(TSBAY(Seq(s,l,ia))=TSBAY(Seq(s,l,ib)))

∧(TSROW(Seq(s,l,ia))=TSROW(Seq(s,l,ib)))(24)

∧(ia≥ib)

$<span\; class="notranslate">\; \&DoubleRightArrow;</span>\mathrm{<span\; class="notranslate">\; TSLAYER</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Seq</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; ia</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; TSLAYER</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; Seq</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; ib</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>$

For any task of the sequence, task=Seq(s, l, ia), the start time of the bridge crane can be determined according to formula (25):

SLTStart (s, l, task) = post (s) + (task-1) (QCTT _{s, l} + QCMT _{s, l} ) (25)

For export shipment, according to SLTStart(s, l, task) and the position of the corresponding container in the yard (y=BLOCK(s, l, task), yb=YBAY(s, l, task)), according to the formula ( 26) It is possible to get the start time of the collection card in the yard:

TRUCKTStart(s, l, tast) ≤ SLTStart(s, l, task) - TRUCKT(s, l, y, yb) (26)

Assuming that the collection truck resources are sufficient, and the operation time of the gantry crane in the yard is also determined, it is set as YCT. The expected time for the gantry crane to start working tasks can be calculated by formula (27):

YCTStart(s, l, task)

≤TRUCKTStart(s,l,task)(27)

≤SLTStart(s,l,task)-TRUCKT(s,l,y,yb)-YCT

可以得到每一个时间t∈TIME，有龙门吊任务的Bay位。该关系采用四维整数0/1矩阵YBAYTIME表示，元素表示堆场blk的Bay位ybay在t的任务，定义为YBAYTIME(blk，ybay，task，t)∈{0，1}。According to YCTStart(s, l, task) of all (s, l, task), combined with the time discretization interval TINT, so that

Each time t∈TIME can be obtained, and there is a Bay position for the gantry crane task. The relationship is represented by the four-dimensional integer 0/1 matrix YBAYTIME, and the elements represent the tasks of the Bay position ybay of the yard blk at t, defined as YBAYTIME(blk, ybay, task, t) ∈ {0, 1}.

Therefore, by simply counting YBAYTIME(blk, ybay, task, t), and combining tasks, YBAYTIME(blk, ybay, t) can be obtained, as shown in formula (28):

$\mathrm{<span\; class="notranslate">\; YBAYTIME</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; blk</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; ybay</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; task</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}\mathrm{<span\; class="notranslate">\; YBAYTIME</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; blk</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; ybay</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; task</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 28</span>}<span\; class="notranslate">\; )</span>$

For the Bay position of the same blk, it is assumed that there are at most two gantry cranes working at the same time. Then, calculate the number of gantry cranes in each yard blk according to QCYTQ(blk, t), such as formula (29):

$\mathrm{<span\; class="notranslate">\; QUR</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; blk</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; \{</span>{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; ybay</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; YBAYTIME</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; blk</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; ybay</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 29</span>}<span\; class="notranslate">\; )</span>$

Thus, the number QCTQ(t) of gantry cranes required at any time t can be obtained, as shown in formula (30).

QCTQ(t) = ∑ _blk (QCYTQ(blk, t)) (30)

Through statistical processing, the estimated value QCQ of the number of gantry cranes can be obtained, such as formulas (31) and (32).

QCQ＝max{QCTQ(t)} (31)

$\mathrm{<span\; class="notranslate">\; QCQ</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&Right\; Arrow;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; NT</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; w</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; \{</span>\underset{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; \&Right\; Arrow;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; w</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; mean</span>}}<span\; class="notranslate">\; \{</span>\mathrm{<span\; class="notranslate">\; QQ</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \}</span><span\; class="notranslate">\; \}</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 32</span>}<span\; class="notranslate">\; )</span>$

Equation (31) seeks the maximum value; while Equation (32) performs smoothing first, where w is the smoothing window.

According to QCTQ(t), the distribution of the number of gantry cranes changing with time can be calculated, which provides a basis for finer control of the start, utilization and shutdown of gantry cranes.

The above model decomposes the task and gradually maps it to the operation of the gantry crane, inversely calculates the parallel gantry crane operation tasks per time through the time of the gantry crane operation task, and calculates the final number of gantry crane startups through statistical criteria. This process does not involve complex mathematical programming models and algorithms, and can quickly calculate the configuration of the number of gantry cranes to start in ultra-large ports.

In summary, the method disclosed in the present invention calculates the overall configuration of the starting quantity of gantry cranes in the entire terminal according to the berthing plan and stowage plan; supports parallel task operations of multiple ships and multiple operation lines; it is a kind of starting quantity of gantry cranes in container terminal yard The fast approximate overall planning method of is practical.

The allocation of the number of gantry cranes to start is an important issue that affects the energy saving and consumption reduction of the terminal operation system, and simple calculation through experience has great risks. Through the overall planning method disclosed in the present invention, under the condition that the operation plan has been fully considered, the starting quantity of the gantry crane is calculated in turn, which is fast and accurate. The method disclosed by the invention is implemented on the existing container terminal operation system, and the basic operation data of the existing software system can be fully used to quickly estimate the number of gantry cranes started.

Description of drawings

Further illustrate the present invention below in conjunction with accompanying drawing.

Fig. 1 schematic diagram of an implementation process of the present invention

Detailed ways

The method disclosed in the present invention will be described below in conjunction with accompanying drawing 1 .

The goal of this method is to calculate the configuration of gantry cranes. The typical application scenario is how to determine the number of gantry cranes to start when making a 24-hour berthing plan and stowage plan, so as to reduce the energy consumption of gantry cranes. The input of this method is the berthing plan and the stowage plan, especially the operation task sequence of the operation line. First of all, the operation lines of all ships are processed as parallel machines, and the task sequence of each operation line is processed independently. According to the assumption that the bridge crane is fully utilized, the start time of each task is calculated, and then the start time of the truck in the yard is calculated. Then calculate the starting time for the gantry crane to perform the task. Then, discretize the time. Conversely, it is possible to determine the task of operation at any time, so as to determine the storage yard and bay position of the task, and aggregate the tasks into the bay position, and merge them according to the continuity of the bay position. Get the configuration of the number of gantry cranes for each yard at any time. Finally, the approximate number of gantry crane configurations is calculated according to statistical criteria, and the distribution of gantry crane configurations over time can be obtained. Finally, according to the number of gantry cranes and the information generated in the calculation process, the berthing plan and stowage calculation of the next batch of ships can be adjusted.

Although the above model discloses the present invention, for those of ordinary skill in the art, many improvements can also be made without departing from the concept and scope of the present invention proposed by the claims, especially: 1) Adjustment of calculation process; 2) weakening or strengthening of basic data and assumptions; 3) statistical method of approximate calculation. Moreover, these improvements and adjustments still ensure that the number of gantry crane starts can be estimated quickly and conveniently.

Claims (4)

1. a container pier storage yard gauntry crane starts the program evoluation and review technique of quantity, it is characterized in that: comprise following characteristics:

1) according to berthing schedule and allocate plan, the gauntry crane that calculates whole harbour starts the quantity overall arrangement;

2) the parallel task operation of the many operating lines of the many boats and ships of support;

3) be a kind of quick approximate calculation method.

2. method according to claim 1 is characterized in that: described characteristics 1), and from berthing schedule and the allocate plan sequence that sets the tasks; Calculate the task start time of bridge crane, the task start time of truck, the task start time of gauntry crane successively according to task sequence, after time discretization, calculate task, Bay position, stockyard of each time etc. conversely.

3. method according to claim 1 is characterized in that: described characteristics 2), decomposing the boats and ships task according to the consideration plan is operating line, and every operating line is obtained Bay position job sequence, and every Bay position is obtained collecting the wiring job sequence.

4. method according to claim 1, it is characterized in that: described characteristics 3), by task being decomposed and being mapped to gradually in the operation of gauntry crane, calculate the parallel gauntry crane job task of time per unit conversely by the time of gauntry crane job task, calculate that by statistical criteria last gauntry crane starts quantity.

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