Tower crane optimization method, system and equipment based on BIM (Building Information Modeling) and genetic algorithm and storage medium

Abstract

The invention discloses a BIM (Building Information Modeling) and genetic algorithm-based tower crane optimization method, system and equipment and a storage medium, and the method comprises the following processes: selecting a tower crane model according to a construction environment and requirements; carrying out BIM modeling on the construction site to obtain a BIM model, and determining the position range of the tower crane; based on the construction site data and the tower crane model in the BIM model, establishing a tower crane mathematical model, and establishing a target function with minimum construction time and cost as a target; and solving the target function by adopting a genetic algorithm to obtain an optimal tower crane arrangement position. The optimization efficiency is improved, the collision risk is avoided, the cost is reduced, and the safety is improved.

Description

Technical Field

[0001] The invention belongs to the field of construction and relates to a tower crane optimization method, system, equipment and storage medium based on BIM plus genetic algorithm. Background Art

[0002] As one of the key equipment on the construction site, tower cranes (abbreviated as tower cranes) play an important role in construction projects, especially in the construction of high-rise buildings. The layout planning of tower cranes directly affects the construction efficiency, construction period and cost. However, the traditional tower crane layout planning method usually relies on the experience of technicians, and the location of the tower crane is determined by on-site observation combined with manual calculation. This method often has certain limitations.

[0003] The optimization of tower crane layout planning involves many complex factors, such as site constraints, building shape and size, type and quantity of construction materials, model and configuration of tower cranes, and layout of other construction equipment, etc. These factors are interrelated, and even experienced project technicians find it difficult to fully consider all possible impacts.

[0004] The following defects and deficiencies exist in the existing tower crane optimization process: Unable to handle complex environmental constraints: Traditional tower crane layout methods are difficult to effectively optimize the tower crane position in complex environments. For example, existing methods are difficult to handle the collision between tower cranes and surrounding buildings, structures or pipelines, which increases uncertainty and accident risks during construction.

[0005] Low optimization efficiency: The existing tower crane layout mainly relies on manual adjustment and optimization. Especially when facing high-rise or multiple tower crane layouts, the calculation workload is huge and it is difficult to quickly find the optimal solution, resulting in low work efficiency and increased costs to a certain extent.

[0006] Lack of data support: Traditional layout methods rely more on experience and judgment, lack of mathematical simulation of building models and tower crane lifting processes, and are unable to minimize material transportation time and costs during the layout process. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a tower crane optimization method, system, equipment and storage medium based on BIM plus genetic algorithm, which improves the optimization efficiency, avoids collision risks, reduces costs and improves safety.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A tower crane optimization method based on BIM and genetic algorithm includes the following processes: Select the tower crane model according to the construction environment and requirements; Carry out BIM modeling of the construction site, obtain the BIM model, and determine the location range of the tower crane; Based on the construction site data and tower crane model in the BIM model, a tower crane mathematical model is established, and an objective function with the goal of minimizing construction time and cost is established; The genetic algorithm is used to solve the objective function and obtain the optimal tower crane layout position.

[0009] Preferably, the tower crane model is selected according to the tower crane working range requirements, lifting weight and lifting height requirements.

[0010] Preferably, in the BIM model, the entire main building floor plan is divided into several demand areas, and the coordinates of each demand area are the coordinates of its own center point; the processing shed or stacking area of ​​the main materials hoisted by the tower crane serves as the material supply area, and the material supply area is set within the coverage range of the tower crane and does not overlap with the range of the tower crane and the planned building; the position range of the tower crane is determined according to the distance between the tower crane and the demand area and the material supply area.

[0011] Preferably, basic rule assumptions are made for the mathematical model of the tower crane: the position coordinates of the tower crane are the starting point of the tower crane hook lifting; the tower crane's boom completely covers the proposed building; the lifting point of the tower crane hook is the ground; the time for the slow gear lifting of the tower crane is ignored; the tower crane model; the positions of the material supply area and the demand area are simplified into rectangular areas, and the coordinates of the geometric center point of the rectangle are the lifting points of the materials; the height of the tower crane meets the requirements of the lifting height of the demand area; the material demand for different demand areas is determined, and the demand for different demand areas is different; and the idle time of the tower crane is ignored.

[0012] Preferably, when establishing the objective function, the lifting distance, lifting speed and lifting time are determined.

[0013] Preferably, in the mathematical model of the tower crane, the tower crane base is modeled as a regional constraint, with the tower crane position, the supply and demand area and the demand area being constrained to remain non-overlapping with each other.

[0014] Preferably, the process of solving the objective function by genetic algorithm is as follows: setting the basic parameters of genetic algorithm; initializing the population size, which is the coordinates of the crane position; using the objective function value as the fitness value of the individual; firstly making a judgment, if the number of iterations is less than or equal to the limit value, then iterative evolution is performed, if it is greater than the limit value, then the cycle is stopped, and each iteration cycle must go through selection, crossover, and mutation to search for the optimal solution; combining the offspring into a new population and comparing it with the population of the previous generation. The total time calculated according to the objective function is used as the fitness value, and the individual with a smaller fitness value is better. The new and old populations are compared, and the better individuals are selected and retained as the new population for the next iteration cycle.

[0015] A tower crane optimization system based on BIM and genetic algorithm, comprising: The tower crane model selection module is used to select the tower crane model according to the construction environment and requirements; BIM modeling module, used to perform BIM modeling on the construction site, obtain the BIM model, and determine the location range of the tower crane; Mathematical modeling module, used to establish a mathematical model of the tower crane based on the construction site data and tower crane model in the BIM model, and to establish an objective function with the goal of minimizing construction time and cost; The solution module is used to solve the objective function using a genetic algorithm to obtain the optimal tower crane layout position.

[0016] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the tower crane optimization method based on BIM and genetic algorithm are implemented.

[0017] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the tower crane optimization method based on BIM plus genetic algorithm are implemented.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention solves various limitations of traditional methods by introducing intelligent optimization algorithms and BIM technology, thereby improving optimization efficiency: utilizing the global search capability of genetic algorithms, it effectively solves the tower crane layout optimization problem under multiple constraints, and can quickly generate multiple feasible solutions, thereby improving the efficiency of tower crane layout. Avoid collision risks: combined with BIM technology, the present invention can simulate the tower crane layout process, automatically identify collision problems with surrounding buildings, structural pipelines, etc., and adjust the plan in a timely manner. Reduce costs and improve safety: through mathematical modeling and intelligent optimization, the present invention can accurately calculate the tower crane's lifting time, path and required costs, significantly reducing construction costs, while reducing safety hazards caused by improper layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the lifting height of the tower crane of the present invention; Figure 2 It is a schematic diagram of the horizontal motion trajectory of the tower crane of the present invention; Figure 3 It is a schematic diagram of the vertical motion trajectory of the tower crane of the present invention; Figure 4 It is the relationship diagram between the vertical lifting speed and the lifting weight of the present invention. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" used in this article includes any and all combinations of one or more related listed items. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0023] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0024] The tower crane optimization method based on BIM and genetic algorithm described in this embodiment includes the following process: Select the tower crane model according to the construction environment and requirements.

[0025] Carry out BIM modeling of the construction site, obtain the BIM model, and determine the location range of the tower crane.

[0026] Based on the construction site data and tower crane model in the BIM model, a mathematical model of the tower crane is established, and an objective function with the goal of minimizing construction time and cost is established.

[0027] The genetic algorithm is used to solve the objective function and obtain the optimal tower crane layout position.

[0028] The specific implementation process is: 1. Tower crane selection According to the project construction site overview and combined with the following three factors, the tower crane model is selected.

[0029] (1) Work scope requirements Working range (arm length): The operating radius of the tower crane refers to the distance from the farthest lifting point of the tower crane to the rotation center, that is, the distance that the trolley can run on the tower crane arm. For example, the working range of a 50-type tower crane is 3-50m. The intersection of the horizontal and vertical directions of the tower crane's boom is the origin, the boom direction is the positive direction of the X axis, and the tower top direction is the positive direction of the Y axis. Its working range coordinates are (3,0)-(50,0).

[0030] The tower crane at the construction site should cover the entire building to be built as much as possible (one span can be left for manual transportation). For the convenience of construction, it should also cover the warehouse, mixing station, material yard and some processing sites (rebar processing shed, woodworking processing shed). For projects using large formwork, it is necessary to cover all construction sites.

[0031] (2) Lifting capacity requirements Lifting capacity: Lifting capacity refers to the weight of objects that the tower crane hook can lift, which is mainly completed by slings, slings, and hooks. Usually, the length of the hook on the tower arm is related to the lifting weight. Different distances correspond to different lifting capacities. The farther the hook is from the center line of the tower crane, the smaller the lifting capacity. The maximum rated lifting capacity refers to the weight that the tower crane can lift when the hook is moved to the farthest end. The maximum lifting capacity of the QTZ63 (5010) tower crane is 5 tons, and the maximum rated lifting capacity is 1t. If the actual length of the installed boom is less than 50m, the lifting capacity when the hook is moved to the farthest end is greater than 1t.

[0032] (3) Lifting height requirements Lifting height: It is the maximum vertical distance allowed between the hook support surface and the tower crane reference plane when the tower crane is at its maximum height and the hook is at its minimum amplitude. Figure 1 The lifting height of the tower crane can be displayed intuitively.

[0033] Lifting height: H = h 1+ h 2+ h 3+ h 4+ h house in, h 1-The length of the tower crane hook, rigging and wire rope is generally 1.5-6m, and longer in special cases.

[0034] h 2- The height of lifting heavy objects is generally 0.5m-2m, and can reach about 2.5m when lifting formwork.

[0035] h 3-The safe distance left under the lifted objects is generally more than 2m.

[0036] h 4- The height of the protective scaffolding outside the construction floor. Many projects now use climbing frames, which are generally above 1.2m.

[0037] h Room - The height of the proposed building.

[0038] Therefore, the tower crane boom should be at least 5.2m higher than the proposed building (1.5+0.5+2+1.2=5.2m).

[0039] 2. BIM Modeling of Engineering Projects The realization of mathematical calculation process depends largely on a large amount of timely input, and accurate identification of specific information from BIM model is the key to produce feasible solutions. In this context, BIM is mainly used to complete two tasks: one is space detection and point identification, which is used to divide the supply area, demand area, tower crane position, and determine their coordinates and spatial dimensions; the other is to calculate the amount of materials required for lifting, including the demand quantity of each demand area and the quantity of supply area.

[0040] 1. BIM model includes: First, the structural model is mainly based on the drawings provided by the design unit to model the load-bearing structures such as walls, columns, beams, slabs, and foundations, and the engineering quantity of steel bars, formwork, wooden beams, and scaffolding in the corresponding parts can be calculated.

[0041] The second is the three-dimensional construction support model, which is created by the general contractor (or subcontractor) and most of which involve temporary components such as scaffolding and formwork; The third is the three-dimensional construction site model, which includes a three-dimensional site terrain model, a construction equipment model and a facility model. The facility model may include existing surrounding buildings and temporary site facilities.

[0042] Before the project starts, with a digital terrain model of the construction site, managers can plan the site layout in advance, such as determining resource supply points and tower crane locations, and build three-dimensional models of construction equipment, such as tower cranes, to support dynamic three-dimensional simulation.

[0043] 2. The BIM model restores the construction site.

[0044] The construction site restored by BIM modeling includes two parts. One is the area within the boundary of the project, that is, the part within the red line, including material and equipment yards, temporary roads, etc.; the other is roads and existing buildings outside the red line that may be affected by the project.

[0045] 3. Determine the demand area.

[0046] On a certain floor construction surface, in order to reduce the burden on workers and improve the efficiency of machinery use, the tower crane needs to transport the processed materials to different coordinate positions. According to the floor dimensions of the building, the dimensions and number of functional spaces, the entire main floor plan of the building is divided into several demand areas. The coordinates of each demand area are the coordinates of the center point of the corresponding demand area. The spatial coordinates and plane dimensions of each demand area are located with the help of Revit software.

[0047] 4. Determine the material supply area.

[0048] The material yard at the construction site includes steel processing shed, wood processing shed, formwork yard, block or brick yard, mortar mixing station, scaffolding storage area, etc. The processing shed or storage area of ​​the main materials hoisted by the tower crane are set within the coverage of the tower crane, and their location cannot overlap with the tower crane or the scope of the planned building.

[0049] According to the engineering survey statistics and the opinions of engineers with rich experience on site, the purpose and floor space of the materials to be hoisted are counted. Combined with the characteristics and limitations of the layout of different material supply areas, the location coordinates of several layout plans are preliminarily determined. 5. Preliminarily determine the location of the tower crane.

[0050] Previously, the building was divided into several different demand areas according to the structural characteristics of the proposed building. The sizes and spatial positions of the different materials that need to be hoisted in the material supply area have been determined. Now, the position of the tower crane is preliminarily selected. The shorter the hoisting time of the tower crane, the better the position. On the premise of meeting the coverage requirements, the smaller the distance between the tower crane and the demand area and the material supply area, the shorter the hoisting time required. Then, the position range of the tower crane is preliminarily determined according to the requirements of the tower crane attachment distance.

[0051] 6. Determine the project quantity.

[0052] Through the calculation and statistics of the Revit platform and on-site technicians, the demand for different materials in each demand area is used as input data for the optimization program.

[0053] 3. Mathematical modeling.

[0054] Based on the construction site data and tower crane models in the BIM model, the problem of tower crane layout planning is studied by constructing a mathematical model in the tower crane lifting project. The parameters needed, their units and meanings are shown in Table 1.

[0055]

[0056]

[0057]

[0058]

[0059] 1. Make basic rule assumptions for the tower crane mathematical model.

[0060] (1) The position coordinates of the tower crane are the starting point for the crane hook to lift.

[0061] (2) In the layout planning, the tower crane's boom completely covers the proposed building.

[0062] (3) At the construction site, some recycled formwork and wooden beams will be stored on the unloading platform. The tower crane hook can lift the materials through the unloading platform. However, the lifting point of the hook in this study is all lifted from the ground.

[0063] (4) When a tower crane is lifting materials at a construction site, it first uses a low-speed gear to lift, and then switches to a gear corresponding to the load. The time for lifting at a low speed is very short, so the time for lifting at a slow speed of the tower crane is ignored in this study.

[0064] (5) There is a one-to-one correspondence between material supply points and material supply areas, and between demand points and demand areas.

[0065] (6) The coordinates of the material supply area are pre-selected based on the engineer’s experience and the site conditions of the construction site.

[0066] (7) Step 1 of the tower crane model selection is pre-set.

[0067] (8) The location of the material supply area is simplified into a rectangular area, and the coordinates of the geometric center point of the rectangle are the lifting points of the material.

[0068] (9) The demand area is divided into different demand points according to the shape of the proposed building and the experience of engineers, and the demand area is also simplified into a rectangular area.

[0069] (10) The height of the tower crane meets the lifting height requirements of the demand area.

[0070] (11) The material demand in different demand areas is known, and the demand in different demand areas is also different.

[0071] (12) The idle time of the tower crane is not taken into account, that is, the tower crane completes one lifting task and then proceeds to the next lifting task.

[0072] 2. Establish the objective function.

[0073] (1) The optimization objective function of the tower crane is to minimize the construction time and cost.

[0074] fc ( X , Y , Z )=min C =min[ TCr +( C b+ Ce ) n ] in, T - The total time required for the tower crane to lift at a certain location (unit: day). The lifting time is directly calculated in minutes, and then divided by the number of shifts per day; C -Total cost of the tower crane during service time (unit: yuan);Cr - Daily rental of tower crane (unit: yuan); Cb - Installation cost of tower crane foundation. The installation cost of different types of tower cranes is different (unit: yuan); Ce - The cost of tower crane entry and exit. The cost of tower crane entry and exit varies for different models (unit: yuan); n - The number of tower cranes (unit: unit).

[0075] (2) Determination of lifting distance.

[0076] The coordinates of the tower crane are ( X , Y , Z ), the position coordinates of the material supply point are ( XSi , YSi , ZSi ), the location coordinates of the demand area are ( XDj , YDj , ZDj ),use L ( Si ) represents the horizontal distance between the material supply point and the crane, L ( Dj ) represents the horizontal distance between the demand point and the tower crane. 2 in the figure below represents the horizontal movement trajectory of the tower crane when completing a transportation task. Figure 3 It represents the motion trajectory of the tower crane in the vertical direction to complete a transportation task. These two movements are also the main processes for the tower crane to complete a lifting task. In addition, the time for loading and unloading goods needs to be considered. This is also a key factor in the time required to complete the lifting task, especially when transporting some irregularly shaped materials.

[0077] According to the coordinates in the figure, the distance relationship between the tower crane, material supply point and demand point can be obtained as follows:

[0078]

[0079]

[0080] LSD= | L(Si)-L(Dj) | Hij =| ZSi - ZDj |

[0081] in, L ( Si ) - the horizontal distance between the material supply point and the tower crane, the distance from the center of the tower crane hook to the material supply point on the horizontal plane (unit: m);L ( Dj ) - the horizontal distance between the demand point and the tower crane, the distance from the center of the tower crane hook to the demand point on the horizontal plane (unit: m); Lij - The horizontal distance between the supply point and the demand point, the distance from the supply point to the demand point on the horizontal plane (unit: m); LSD - The horizontal distance between the supply point and the tower crane, the horizontal distance between the demand point and the tower crane, the difference between the two; that is, the distance the tower crane travels when transporting materials from the supply point to the demand point (unit: m); Hij - The vertical distance between the supply point and the demand point, that is, the distance the tower crane vertically lifts the materials from the supply point to the demand point. As the number of floors increases, the distance also increases (unit: m); θij - The angle between the supply point and the demand point on the horizontal projection, that is, the angle the tower crane rotates each time it lifts (unit: rad).

[0082] (3) Determination of lifting speed.

[0083] According to the actual situation on site, the working principle of the tower crane is similar to that of a manual transmission car. It is generally divided into three gears: I, II, and III, and the working speed increases in sequence. When lifting materials, first use the slow gear to speed up, and then switch to the corresponding high gear according to the weight of the material. The three working speeds of the tower crane are determined below.

[0084] ① Rotation speed Vw - The rotation speed of the tower crane arm from the supply point to the demand point. The rotation speed has nothing to do with the weight of the hoisted material, that is, it is a constant value, about 0.6r / min.

[0085] ②Luffing speed Vrij - The radial movement speed of the tower crane from the material supply point to the demand point, that is, the movement speed of the tower crane trolley The luffing speed of the tower crane is related to the weight of the hoisted material.

[0086] ③Vertical lifting speed, Vvij - The vertical lifting speed of the tower crane from the supply point to the demand point.

[0087] According to the actual situation on site, the tower crane used in this study only works at 2 times the rate. The relationship between vertical lifting speed and lifting weight is as follows: Figure 4 shown.

[0088] When the single lifting weight is less than or equal to 1.0t, the lifting speed is 80m / min; when the single lifting weight is greater than 1.0t and less than or equal to 3t, the lifting speed is 40m / min.

[0089] The vertical lifting speed is closely related to the lifting weight, and the lifting weight is related to the lifting radius, that is, the load and the load radius. The relationship between the load and the load radius in the tower crane manual is shown in Table 2.

[0090] Table 2 Tower crane load-load radius relationship

[0091] As can be seen from the table above, when the load radius is less than or equal to 24.9m, the load can reach 3t; when the load radius is between 26-56m, the relationship between the load and the load radius is irregularly distributed and does not satisfy a simple linear function relationship. Origin is used to fit the relationship in this interval, and through verification and comparison, it is found that the exponential function best fits their functional relationship. The exponential function is as follows: Lcij =226.08× Lm -1.339 The relationship between load and load radius is as follows:

[0092] Lm - Load radius, i.e. the horizontal distance between the material supply point and the tower crane, the horizontal distance between the demand point and the tower crane, whichever is greater (unit: m); Lcij - Under the constraints Lm The load of the tower crane from the material supply point to the demand point (unit: t).

[0093] When the object is a certain distance away from the ground, make sure that the lifting material is tied firmly and safely before switching to the corresponding high speed gear; when the material is moved to the required point and lowered into place, it must also be switched to the low speed gear. In other words, the tower crane should gradually transition from low speed to high speed during operation, and should not be pushed suddenly and quickly from low speed gear to fast gear or from fast gear to low speed gear, to avoid impact during lifting and lowering. Of course, the most important thing is to ensure the safety of the tower crane during vertical lifting.

[0094] (4) Determination of lifting time ① Turnaround time

[0095] Twij - The time it takes for the tower crane's boom to rotate once from the material supply point to the demand point. The greater the horizontal distance between the material supply point and the demand point, the greater the parameter.

[0096] ②Amplitude change time

[0097] Trij - The radial movement time of the tower crane from the material supply point to the demand area, that is, the time the tower crane trolley needs to run.

[0098] The hook of the tower crane moves from the center point of the tower crane to the material supply point. After bundling the material and completing the rotation and vertical lifting, the material is now in a straight line with the center of the tower crane and the demand point. The material is then moved to the demand point. If the difference between the distance between the tower crane and the material supply point and the distance between the tower crane and the demand point is small, then the distance moved by the tower crane hook is smaller, that is, the distance and time of the trolley running are shorter.

[0099] Therefore, the time required for horizontal material transportation by a tower crane is: TLij =max( Trij , Twij )+ α .min( Trij , Twij ) TLij - Horizontal transportation time from the material supply point to the demand point; α --The synchronization parameter of horizontal movement can be set to 0.25 to take into account unexpected situations such as weather conditions at the construction site and safety shutdown inspections.

[0100] ③Vertical lifting time

[0101] Tvij - The vertical lifting time of a tower crane from the supply point to the demand point.

[0102] As the height of the floor increases, the vertical lifting distance of the tower crane increases accordingly, and the time becomes longer. The speed of vertical lifting is related to the weight of the lifting material, so the vertical lifting time of the tower crane is constantly changing.

[0103] It can be concluded that the time required for a tower crane to lift from the material supply point to the demand point is as follows: tij =max( TLij , TVij )+ β .min( TLij , TVij )+ TL + TU tij - The time it takes for a tower crane to lift materials from the material supply point to the material demand point; β -- Synchronization parameters for horizontal and vertical movement, set the value to 1.0; TL - The time for loading the goods at the material supply point, i.e. the time for tying, hooking and slowly lifting the hook; TU - The time to unload the goods at the demand point, that is, the time to untie, unhook and slowly drop the hook.

[0104]

[0105] Nij - The number of times the material needs to be lifted from the supply point to the demand point; Qij - The total amount of each demand area, that is, the weight of materials that need to be lifted from the supply point to the demand point; Pij - Single lifting capacity, that is, the weight of a single lifting of the tower crane from the material supply point to the demand point, and calculate the horizontal distance between the tower crane and the material supply point at this time L ( Si ), the horizontal distance between the tower crane and the demand area L ( Dj ), take the larger value of the two LSD =max[ L ( Si ), L ( Dj )], then find out LSD The corresponding lifting capacity is the single lifting capacity.

[0106]

[0107] T - The total time required for the tower crane to lift; N - the number of demand areas; Tij - Lifting time for each demand area.

[0108] 3. Constraints.

[0109] The crane base is modeled as a regional constraint to keep the crane position non-overlapping with any supply and demand areas, and the following formula is established:

[0110]

[0111] in,( X , Y )--the coordinates of the tower crane in the X and Y axis directions; ( XSi , YSi ) - Coordinates of the feeding point in the X and Y axis directions; ( XDj , YDj ) - the coordinates of the demand point in the X and Y axis directions; LX , LY - The length of the tower crane along the X and Y axes; LXSi , LYSi - The length of the material feeding point in the X and Y axis directions; LXDj , LYDj - The length of the demand point in the X and Y axis directions.

[0112] Assuming that all materials hoisted by the tower crane are hoisted from the ground, the material supply area is located in the horizontal plane and cannot overlap with the position of the tower crane, and of course cannot overlap with the demand area. This leads to the following formula:

[0113] The external frame of the proposed building is a working platform set up to ensure the smooth progress of the construction process. The external frames commonly used in my country's construction sites are climbing frames and scaffolding. The specification requires that the frame width of the climbing frame cannot exceed 1.2m and the distance from the wall is 0.4m. According to the data of the engineering survey, the frame width of the climbing frame is about 0.7-0.8m, so the outer side of the climbing frame is 1.1-1.2m away from the wall; the scaffolding is generally required to be 0.2m away from the wall, the width of the frame is 1m, and the exposed horizontal bar is 0.1m, totaling 0.2+1+0.1=1.3m. A certain safety distance of 0.2m must also be left between the external frame and the tower crane. The standard section size of the QTZ63 tower crane is 1.8m×1.8m×2.8m, so the distance between the center point of the tower crane and the outer edge is 0.9m. Therefore, when the external frame is a climbing frame, the distance between the center point of the tower crane and the outer edge of the building is 2.2-2.3m; when the external frame is a scaffolding, the distance between the center point of the tower crane and the outer edge of the building is 2.4m. The value taken in this article is 2.4m.

[0114] Right now ≥2.4 In addition, when the height of the proposed building exceeds the allowed independent working height of the tower crane, the tower crane must be attached to an object that meets the tower crane attachment strength requirements through a wall connection (usually attached to the proposed building, that is, the demand area mentioned in this article). The length of the attachment rod from the building needs to meet certain requirements. For the tower crane model QTZ63, the length is 3.5-4m according to the instruction manual. At this time, the following formula is satisfied: ≥3.5 The maximum attachment distance of the tower crane shall not exceed 6m:

[0115] 4. Model solution The genetic algorithm is selected to solve the model. The principle of the genetic algorithm is introduced below: A general genetic algorithm includes the following basic operations: encoding, fitness calculation, selection, crossover, mutation and termination.

[0116] (1) Coding The first step in implementing a genetic algorithm is to clearly encode the problem to be solved. There are generally two encoding methods: Real number coding: Genes are directly represented by real numbers, which is easy to understand and does not require a decoding process, but it is prone to converge prematurely and fall into a local optimum.

[0117] Binary coding: simple and easy, highly stable, and has a large population diversity, but requires a large storage space.

[0118] (2) Fitness function First, map the objective function to be calculated into a fitness function, and then select the fitness function calibration. There are several ways to do this: Linear Scaling: f ,= af + b。

[0119] Truncation: f ,= f -( f - cσ ).

[0120] Power Scale: f ,= fK。

[0121] Index calibration: f ,=exp(- bf ).

[0122] (3) Selection Selection can be understood as reproduction in biology. A pair of individuals with stronger vitality are called parents. The parents pass their genes to the next generation. In this process, individuals with stronger vitality will have a higher probability of producing one or more offspring in the next generation.

[0123] (4) Cross Simple crossover is implemented in two steps. The first step is to randomly pair the bit string individuals in the pairing pool. The second step is to randomly select crossover points and cross-breed the matching bit strings to generate a new pair of bit strings. The effectiveness of genetic algorithms mainly comes from selection and crossover operations. Although the selection operation can select excellent individuals from the old population, it cannot create new individuals. Crossover simulates the reproduction phenomenon in the evolutionary process and creates new excellent individuals by exchanging and combining two individuals.

[0124] (5) Variation In the process of evolution of organisms, various factors such as the environment may cause gene mutations, resulting in individuals that are very different from the previous generation or even completely different from each other. This is called mutation. Mutation can produce new individuals. In the algorithm, by simulating this change, the diversity of the population can be guaranteed, making the algorithm's search space larger and larger, and avoiding falling into local solutions. Selection and crossover allow the population to reproduce, but some genetic information may be missed. This information is very important for organisms, and mutation can prevent this omission. In the algorithm, mutation causes the value of a certain bit of the string to change randomly, provided that the probability is very small. When it is combined with crossover in a restrained manner, Together, this prevents the population from over-maturating and losing important concepts.

[0125] Generally, the operation of a genetic algorithm is considered to be terminated when the following two conditions are met. One is to set the termination algebra. When the number of iterations is greater than the termination algebra, the algorithm terminates; the other is to set a certain rule. When the requirements of the rule are met, the population tends to be stable, no longer evolves, and reaches a stable value, and the algorithm terminates.

[0126] 4. Generation of the Optimal Tower Crane Arrangement Solution According to the mathematical model established earlier and the relevant data coordinates in the BIM model, this information was converted into Matlab programming language for calculation, and the alternative tower crane location was preliminarily determined. Then, the visualization function of BIM was used to check whether there was any spatial conflict, including collision inspection of structures and pipelines, and the optimal tower crane location was obtained.

[0127] The code writing of Matalab genetic algorithm is divided into two parts, one is the main program and the other is the auxiliary program. In the auxiliary program, the specific data of the mathematical model and constraint conditions are written according to the code requirements, the material data of the demand area and the supply area are directly inserted through the Excel table, the space size is provided by the BIM model, and the data used in the main program is directly called in the auxiliary program.

[0128] The specific process of solving the problem using the genetic algorithm in step 3 is as follows: (1) Set the basic parameters of the genetic algorithm: The number of individuals in the population of unit=20; number of evolution iterations number of gen=1000; crossover probability Pc =0.7; mutation probability Pm =0.01.

[0129] (2) Initialize the population size The population size of this model is the crane position coordinates (Xi, Yj), i=1, 2, 3, ⅆ, n; j=1, 2, 3, ⅆ, n. Therefore, each individual in the population represents a solution, that is, a coordinate position. A set of crane positions is randomly generated within the feasible solution as the initial solution, that is, within the boundary range.

[0130] limit_up_x=31200; limit_down_x=16551.3; limit_up_y=-4900; limit_down_y=-7400.

[0131] (3) Fitness function The objective function minimizes time and cost, so the objective function value can be directly used as the individual's fitness value.

[0132] (4) Iteration loop First, a judgment is made. If the number of iterations is less than or equal to the limit (the number of evolution iterations), iterative evolution is performed. If it is greater than the limit, the loop is stopped. Each iteration loop undergoes selection, crossover, and mutation to search for the optimal solution.

[0133] ①Select Tournament selection is to randomly select individuals from the population each time (each individual has the same probability of being selected) to form a group, and select the individual with the best fitness value to enter the offspring population according to the fitness value of each individual. The obtained individuals constitute the new generation population until the new population size reaches the original population size. Therefore, it can be used for both maximization and minimization problems.

[0134] ② Cross Randomly select two individuals from the population as parents. If the two selected individuals are the same, reselect until they are different. According to the characteristics of the decision variables, the average method is used to generate new individuals, that is, the average of the position coordinates of the parents is taken as the new solution. The advantage of taking the average value is that it can avoid the new solution from exceeding the range of the tower crane position.

[0135] ③Variation A random decimal between [0,1] is generated and compared with the mutation factor. If it is less than the mutation factor, mutation occurs. The mutation method is to generate a set of new solutions to replace the original individuals.

[0136] (5) Screening and elimination The offspring are combined into a new population and compared with the previous generation population. The total time calculated according to the objective function is used as the fitness value, and individuals with smaller fitness values ​​are better. The new and old populations are compared, and the better individuals are selected and retained as the new population for the next iteration cycle.

[0137] The following are device embodiments of the present invention, which can be used to perform method embodiments of the present invention. For details not disclosed in the device embodiments, please refer to the method embodiments of the present invention.

[0138] In another embodiment of the present invention, a tower crane optimization system based on BIM plus genetic algorithm is provided. The tower crane optimization system based on BIM plus genetic algorithm can be used to implement the above-mentioned tower crane optimization method based on BIM plus genetic algorithm. Specifically, the tower crane optimization system based on BIM plus genetic algorithm includes a tower crane model selection module, a BIM modeling module, a mathematical modeling module and a solution module.

[0139] Among them, the tower crane model selection module is used to select the tower crane model according to the construction environment and requirements.

[0140] The BIM modeling module is used to perform BIM modeling on the construction site, obtain the BIM model, and determine the location range of the tower crane.

[0141] The mathematical modeling module is used to establish a mathematical model of the tower crane based on the construction site data and tower crane model in the BIM model, and to establish an objective function with the goal of minimizing construction time and cost.

[0142] The solution module is used to solve the objective function using a genetic algorithm to obtain the optimal tower crane layout position.

[0143] In yet another embodiment of the present invention, a terminal device is provided. The terminal device includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions to implement corresponding method processes or corresponding functions; the processor described in the embodiment of the present invention can be used for the operation of a tower crane optimization method based on BIM plus genetic algorithm, including: selecting a tower crane model according to the construction environment and requirements; performing BIM modeling on the construction site to obtain a BIM model and determine the position range of the tower crane; establishing a tower crane mathematical model based on the construction site data and the tower crane model in the BIM model, and establishing an objective function with the minimum construction time and cost as the goal; using a genetic algorithm to solve the objective function to obtain the optimal tower crane layout position.

[0144] In another embodiment, the present invention further provides a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It is understandable that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory.

[0145] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the tower crane optimization method based on BIM plus genetic algorithm in the above-mentioned embodiment; one or more instructions in the computer-readable storage medium are loaded by the processor and execute the following steps: selecting a tower crane model according to the construction environment and requirements; performing BIM modeling on the construction site to obtain a BIM model and determining the position range of the tower crane; establishing a tower crane mathematical model based on the construction site data and tower crane model in the BIM model, and establishing an objective function with the goal of minimizing construction time and cost; using a genetic algorithm to solve the objective function to obtain the optimal tower crane layout position.

[0146] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0147] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0148] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0149] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process.Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0150] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0151] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0152] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0153] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0154] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

[0155] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this patent should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A tower crane optimization method based on BIM and genetic algorithm, characterized in that: The process includes: Select the tower crane model according to the construction environment and requirements; Carry out BIM modeling of the construction site, obtain the BIM model, and determine the location range of the tower crane; Based on the construction site data and tower crane model in the BIM model, a tower crane mathematical model is established, and an objective function with the goal of minimizing construction time and cost is established; The genetic algorithm is used to solve the objective function and obtain the optimal tower crane layout position.

2. The tower crane optimization method based on BIM and genetic algorithm according to claim 1 is characterized in that: The tower crane model is selected according to the tower crane working range requirements, lifting weight and lifting height requirements.

3. The tower crane optimization method based on BIM and genetic algorithm according to claim 1 is characterized in that: In the BIM model, the entire main floor plan of the building is divided into several demand areas. The coordinates of each demand area are the coordinates of its own center point. The processing shed or stacking area of ​​the main materials hoisted by the tower crane is used as the supply area. The supply area is set within the coverage of the tower crane and does not overlap with the tower crane and the scope of the planned building. The position range of the tower crane is determined according to the distance between the tower crane and the demand area and the supply area.

4. The tower crane optimization method based on BIM and genetic algorithm according to claim 1 is characterized in that: The basic rules assumptions for the mathematical model of the tower crane are as follows: the position coordinates of the tower crane are the starting point of the tower crane hook lifting; the tower crane's boom completely covers the proposed building; the lifting point of the tower crane hook is the ground; the time for the slow gear lifting of the tower crane is ignored; the tower crane model; the positions of the material supply area and the demand area are simplified into rectangular areas, and the coordinates of the geometric center point of the rectangle are the lifting points of the materials; the height of the tower crane meets the requirements of the lifting height of the demand area; the material demand for different demand areas is determined, and the demand for different demand areas is different; the idle time of the tower crane is ignored.

5. The tower crane optimization method based on BIM and genetic algorithm according to claim 1 is characterized in that: When the objective function is established, the lifting distance, lifting speed and lifting time are determined.

6. The tower crane optimization method based on BIM and genetic algorithm according to claim 1 is characterized in that: In the mathematical model of the tower crane, the tower crane base is modeled as a regional constraint, with the tower crane position, supply area and demand area being constrained to remain non-overlapping.

7. The tower crane optimization method based on BIM and genetic algorithm according to claim 1 is characterized in that: The process of solving the objective function by genetic algorithm is as follows: setting the basic parameters of genetic algorithm; initializing the population size, which is the coordinates of the crane position; using the objective function value as the fitness value of the individual; firstly making a judgment, if the number of iterations is less than or equal to the limit value, then performing iterative evolution, if it is greater than the limit value, then stopping the loop, and each iteration cycle will go through selection, crossover, and mutation to search for the optimal solution; combining the offspring into a new population and comparing it with the previous generation population; using the total time calculated according to the objective function as the fitness value, individuals with smaller fitness values ​​are better, comparing the new and old populations, screening and retaining better individuals, and using them as the new population for the next iteration cycle.

8. A tower crane optimization system based on BIM and genetic algorithm, characterized in that: include: The tower crane model selection module is used to select the tower crane model according to the construction environment and requirements; BIM modeling module, used to perform BIM modeling on the construction site, obtain the BIM model, and determine the location range of the tower crane; Mathematical modeling module, used to establish a mathematical model of the tower crane based on the construction site data and tower crane model in the BIM model, and to establish an objective function with the goal of minimizing construction time and cost; The solution module is used to solve the objective function using a genetic algorithm to obtain the optimal tower crane layout position.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the tower crane optimization method based on BIM plus genetic algorithm as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the tower crane optimization method based on BIM and genetic algorithm as described in any one of claims 1 to 7 are implemented.

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