Multi-tower crane cooperative driving training system based on virtual reality technology

Abstract

The invention discloses a multi-tower-crane cooperative driving training system based on a virtual reality technology. The multi-tower-crane cooperative driving training system comprises a physical simulation module, a construction scene construction module, a multi-tower-crane cooperative operation module and an interaction and control module. The physical simulation module simulates the motion trail, load change and collision response of the tower crane to ensure that the operation of the tower crane conforms to a real physical rule in a virtual environment; the construction scene construction module generates a virtual construction site scene through a BIM technology; the multi-tower crane cooperative operation module realizes task allocation, path planning and safe distance maintenance among multiple tower cranes; and the interaction and control module provides real-time interaction between the operator and the virtual tower crane. Multiple operators are supported to operate different tower cranes at the same time, and accurate control is achieved through the VR controller and the operation handle. The system provided by the invention can analyze and evaluate the collaborative operation performance of trainees, helps a green tower crane driver to improve the collaborative operation skill of multiple tower cranes, and reduces the safety risk caused by crossing of tower crane coverage ranges in actual operation.

Description

Technical Field

[0001] The invention relates to a multi-tower crane cooperative driving training system based on virtual reality technology, and belongs to the field of engineering construction management. Background Art

[0002] Tower cranes, also known as tower cranes or tower cranes, are indispensable mechanical equipment on modern construction sites, especially in prefabricated building construction. In the process of prefabricated construction, tower cranes can achieve vertical and horizontal material transportation tasks within a large coverage area, so they play a key role in improving the transportation efficiency of the construction site and ensuring the progress of the project. [1] However, due to the limitation of site space and the need for parallel construction of multiple construction sections, some lifting areas between adjacent tower cranes will overlap when arranging the tower crane group. Cross-operation in this area may cause collision risks between booms or between booms and ropes. [2] In large-scale joint construction projects, large-scale overlapping operation areas of tower cranes and frequent cross-operation will greatly increase the probability of collision accidents, thus causing safety hazards. [3] When the working areas overlap, the crane driver not only needs to accurately control the crane's boom and hook, but also must always pay attention to the relative position of the surrounding cranes to avoid collision. [4] In addition, due to the particularity of tower crane operation, the driver has limited vision during work and it is difficult to fully control the dynamics of adjacent tower cranes. Especially in complex multi-tower crane collaborative operation tasks, the operation difficulty increases significantly, which puts higher requirements on the tower crane driver's spatial judgment, operation skills and teamwork ability. [5] Therefore, systematic training for tower crane drivers is particularly important. Effective training can not only help novice drivers quickly master basic operating skills, but also improve their adaptability in complex construction site environments, ensuring that drivers can maintain precise control in high-risk, high-intensity work. [6] . The existing tower crane operation training methods mainly focus on the basic operation of a single tower crane, usually by simulating the control and lifting tasks of a single tower crane to help novice drivers familiarize themselves with the basic operation procedures of the equipment. However, this training method cannot effectively simulate the group-tower operation scene, and lacks systematic training methods for key skills such as spatial relationships, operation coordination, and dynamic avoidance between multiple tower cranes. In addition, single tower crane training is difficult to simulate the cross-operation of multiple tower cranes on actual construction sites, especially in terms of operation in overlapping areas, mutual avoidance, and real-time communication. There are obvious deficiencies, resulting in trainees being unprepared for complex multi-tower crane collaborative operations and unable to fully adapt to the high-risk and high-demand working environment of the actual construction site. At the same time, training on actual sites also faces many problems such as high costs, high risks, and difficulty in ensuring safety.

[0003] In summary, this study has developed a training system that can realize the collaborative operation of multiple tower cranes in a virtual environment, so that novice tower crane drivers can efficiently master the collaborative operation skills of multiple tower cranes, emergency handling capabilities, and communication and collaboration capabilities in a safe virtual environment, reduce training costs, improve training quality, and prepare for tower crane operations at actual construction sites. Summary of the invention

[0004] The present invention provides a multi-tower crane collaborative driving training system based on virtual reality technology, which is used to simulate the collaborative operation of multiple tower cranes in actual construction scenarios, so as to improve the collaborative operation ability, safety awareness and emergency handling ability of novice tower crane drivers under complex working conditions.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The invention provides a multi-tower crane cooperative driving training system based on virtual reality technology, comprising a tower crane physical simulation module, a construction scene building module, a multi-tower crane cooperative operation module and an interaction and control module.

[0007] Preferably, the tower crane physical simulation module includes the establishment of a tower crane model. First, the tower crane model is constructed in Revit, and the three-dimensional modeling of the tower crane's lifting mechanism, running mechanism, slewing mechanism and luffing mechanism is completed according to the "Tower Crane Design Specification GB / T 13752-2017", and then the model is converted into the NWC data format supported by the Navisworks Manage three-dimensional model visualization software. After that, a new Unity project is created, and the tower crane model exported from Navisworks Manage is imported into the project. The three-dimensional model of the tower crane is constructed by establishing various simulation modules and writing tower crane motion scripts. The flow chart is as follows: Figure 1 shown.

[0008] The physical simulation module also includes tower crane motion trajectory simulation, which includes building tower crane arm simulation components, tower crane hook simulation components, tower crane trolley simulation components, and tower crane load simulation components in Unity;

[0009] The tower arm simulation component is responsible for simulating the rotation and pitch motion of the tower crane arm to ensure that its motion trajectory under load is consistent with the actual working conditions, including the simulation of the inertia, friction and other physical properties of the tower arm during rotation;

[0010] The hook simulation component is used to simulate the lifting and swinging of the hook. By calculating the physical response of the hook at different heights and loads, it can achieve accurate feedback during the operation of the hook and ensure the stability and naturalness of the hook's motion trajectory.

[0011] The trolley simulation component is responsible for simulating the translation of the tower crane trolley on the tower arm track. It supports the simulation of the trolley speed, acceleration and friction, so that the trolley movement conforms to the physical characteristics of the real tower crane and can coordinate with other components during operation.

[0012] The load simulation component is used to simulate the weight, inertia and center of gravity position changes of materials during the lifting process, making the lifting process more realistic. It also supports force feedback on tower crane operations under different load conditions, allowing trainees to experience the actual operational difficulty when lifting materials of different weights.

[0013] Next, write and generate C# code classes. Create scripts to control the tower crane's three degrees of freedom: tower arm rotation, hook lifting, and trolley luffing. These simulation components work together to form the core of the physical simulation module.

[0014] Preferably, the construction scene building module uses BIM technology to finely model the construction site scene, including a terrain model, a building model, a lifting component placement area, and a lifting end point position.

[0015] The terrain model is used to construct the terrain features of the virtual construction site environment to make it closer to the real construction site. The model is carefully set in terms of ground details, terrain height difference, material simulation, etc. to enhance the realism and immersion of the virtual environment. In the Unity editor, use the "Terrain" component to add a terrain object. Set the size of the terrain to the corresponding size according to the actual project requirements and the maximum visible range of the tower crane. Then use the "Raise&LowerTerrain" function in the "Terrain" component to edit the height of the construction site terrain and simulate the terrain features of the construction site. Finally, add materials and textures to the terrain, including soil, rocks, etc., to more realistically simulate the surface conditions of the construction site.

[0016] The building model includes various construction buildings and structures, including foundations, columns, floor slabs, etc., accurately restores the geometric shape and material properties of the construction project, and enhances the realism and spatial perception of the scene. Set up various buildings on the simulated construction site (such as scaffolding. In the Unity editor, use "Game Object" > "3DObject" > "Cube" to build a cube as the foundation of the building and the floor slab of each floor. Change the size of the cube by adjusting the "Scale" property in the "Transform" component and set its size to. Then use the "Cube" object to create and add columns and beams. The pillars serve as the vertical part of the entire frame structure, and the beams are connected to the top of each pillar. Finally, add concrete materials to all components, adjust the roughness and reflectivity of the material, etc. to achieve a realistic visual effect.

[0017] The hoisting component placement area is a component lifting position or temporary placement area specially set up in the system, which is used to store different types of components (such as steel beams, concrete slabs, prefabricated components, etc.). In this area, the system can place different types of components in different areas according to factors such as purpose, shape, and weight, so that students can learn to identify different components and reasonably choose the appropriate hoisting method. In addition, the location of the component placement area is set according to the layout of the simulated construction site. The lifting radius of the tower crane must be taken into account, and a reasonable distance layout must be planned to ensure that the components are within the working range of the tower crane, so that students can optimize the lifting path and lifting rhythm. Fences, signs and other safety instructions are set around the component placement area, and obstacles are set up so that students can identify and pay attention to the safe range of lifting before actual lifting, ensuring that the lifting and lowering process of objects complies with safety regulations.

[0018] The final lifting position is used to simulate the final placement point of the actual component, helping trainees to become familiar with the precise positioning and landing point control of the component, and improving their ability to control the lifting end point operation. The end point will be set within the construction site layout, requiring trainees to accurately lift the component to the specified position, such as the scheduled installation area of ​​the high-rise building, the installation point of the prefabricated component on the ground, etc., so as to train trainees to accurately control the lifting end point. The final virtual construction scene is as follows: Figure 2 shown.

[0019] Preferably, the multi-tower crane cooperative operation module includes a task allocation unit and a safety distance maintenance unit, which are respectively responsible for the reasonable allocation of tower crane tasks and the maintenance of safety distances between tower cranes.

[0020] The task allocation unit is responsible for task allocation and scheduling in the multi-crane collaborative operation task. The main function of this unit is to reasonably allocate the specific operation tasks of each crane according to the needs of the construction task, the working capacity of the crane and the conditions of the working environment to ensure the coordinated operation between the cranes. The task allocation example is as follows: Figure 3 As shown in the figure. The unit first classifies different types of lifting tasks, such as lifting heavy objects, precise positioning, and lifting across tower cranes. Each task type has different operating requirements and working conditions. According to the task requirements and the layout of the construction site, the task allocation unit allocates the lifting tasks to suitable tower cranes through genetic algorithms to achieve collaborative operation of multiple tower cranes. Genetic algorithms are an optimization algorithm that simulates the principles of natural selection and genetics. They continuously optimize the quality of solutions through operations such as population selection, crossover, and mutation. In the collaborative operation of multiple tower cranes, genetic algorithms are used for the optimal allocation of tasks.

[0021] The safety distance maintenance unit is a key module in the multi-tower crane collaborative driving training system. It is mainly used to ensure that during the collaborative operation of multiple tower cranes, each tower crane maintains a sufficient safety distance to avoid collisions or other safety accidents. The unit will continuously track the operating position, boom angle, load status and other data of each tower crane, and judge whether the safety distance between the tower cranes meets the requirements based on this information. If a potential safety hazard occurs, the system will issue a warning in time.

[0022] Preferably, the interaction and control module includes a real-time operation control unit and a data recording and analysis unit.

[0023] The main task of the real-time operation control unit is to connect the Unity virtual simulation environment, VR equipment and the tower crane control joystick, so that the operator can control the virtual tower crane in real time through the virtual reality equipment to simulate the real tower crane operation process. In the virtual reality environment, multiple trainees can participate in the operation of the same construction scene at the same time, simulating the scene of group tower operation in reality.

[0024] In terms of the selection of VR head-mounted display devices, HTC Vive Pro 2 has the highest resolution and refresh rate, a wide field of view and precise head tracking technology, and supports SteamVR and Viveport platforms, with balanced overall performance. Therefore, this study selected HTC Vive Pro 2 Professional Basic Edition as the hardware device for tower crane lifting simulation. In terms of the selection of control joysticks, Thrustmaster T.16000M flight joystick was selected as the tower crane lifting simulation joystick. T.16000M is equipped with 3 rotation axes, allowing users to control multiple operation dimensions (such as hook lifting, tower arm rotation, and trolley amplitude adjustment) at the same time, providing a complex and fine control experience similar to real tower crane operation. In addition, due to its standard HID device interface, the T.16000M joystick can be recognized and configured by Unity without additional drivers or middleware. To develop the tower crane driving simulation function using the above VR devices and accessories, it is necessary to configure the HTC Vive Pro 2 head-mounted display and T.16000M joystick through Unity3D, connect with Unity, and build a tower crane driving simulator. Figure 4 shown.

[0025] The data recording and analysis unit is used to record various operation data of operators during the training process, and analyze and evaluate them. By collecting and processing a large amount of operation data, this unit not only helps trainees understand their own operation performance, but also provides data support for the evaluation and improvement of training effects.

[0026] This unit records all the trainees' operation data in real time during the crane's execution, including various crane control instructions (such as boom rotation angle, hook lifting range, trolley movement range, load weight, operation time, etc.). The exported Excel file is as follows: Figure 5 As shown. At the same time, the trainee's operation mode, reaction time, failed or successful task records, number of warnings for the safety distance maintenance unit and other information are recorded to form a complete operation data file. All operation data and feedback information will be stored in the database. And it is managed and classified according to multiple dimensions such as task difficulty, personnel information, and lifting time. The system projects the original multidimensional data into a new dimensional space through principal component analysis (PCA) in order to extract the most informative features. These features (principal components) can help analyze the trainee's operating habits, lack of ability and operating mode. The analysis results can be used to generate an operation evaluation report for the trainee, which includes the trainee's overall performance, the completion of various lifting tasks, the type and frequency of errors, emergency response capabilities and other evaluation contents. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Flowchart of tower crane model construction.

[0028] Figure 2 Construction of virtual construction scene based on Unity.

[0029] Figure 3 Example of lifting task allocation.

[0030] Figure 4 Tower crane driving simulator example.

[0031] Figure 5 The tower crane driver’s operation data collected in real time.

[0032] Figure 6 It is a schematic diagram of the system structure of the present invention. DETAILED DESCRIPTION

[0033] The present invention provides a multi-tower crane collaborative driving training system based on virtual reality technology, which combines virtual reality (VR), physical simulation, network communication and intelligent algorithm, and realizes the training of tower crane operators in multi-tower crane collaborative operation through a series of specific steps. The implementation method describes in detail how to realize the virtual environment and interactive control of multi-tower crane collaborative operation training through Unity engine, VR equipment, operating handle and network communication technology. The following is a specific implementation method of the present invention:

[0034] Step 1: Plan the tower crane operation area

[0035] First, by investigating the actual working environment of the tower crane driver, we understand the space size of the tower crane cab, the layout of the control equipment, and the functions of the operation panel, and plan the operation area of ​​the tower crane driver. On this basis, we define the virtual cab space of the tower crane driver and its interactive operation interface to prepare for the subsequent virtual environment design and operation input.

[0036] Step 2: Equipment installation and configuration

[0037] Install the HTC Vive Pro head-mounted display and positioning base stations: Install the HTC Vive Pro head-mounted display and its left and right positioning base stations at the training venue to ensure that the system can track the position of the head and handles in real time. Ensure that the power supply of the equipment is connected properly and all hardware (including the head-mounted display, positioning base stations, and operating handles) are in working condition.

[0038] Step 3: Unity environment configuration and initialization

[0039] Import the SteamVR plug-in, select Window->Asset Store from the top toolbar of Unity, open the UnityAsset store, and download and install the SteamVR plug-in from it. These plug-ins support compatibility with devices such as HTC Vive Pro, ensuring that VR interactive devices can exchange data with the Unity virtual environment.

[0040] Build a tower crane motion model in the Unity virtual environment. First, build a tower crane model in Revit, complete the 3D modeling of the tower crane's hoisting mechanism, running mechanism, slewing mechanism and luffing mechanism according to the "Tower Crane Design Specification GB / T 13752-2017", and then convert the model into the NWC data format supported by the Navisworks Manage 3D model visualization software. Then create a new Unity project, import the tower crane model exported from Navisworks Manage into the project, and build the tower crane 3D model by establishing various simulation modules and writing tower crane motion scripts.

[0041] Enter the PrefabAsset page of Unity, select the "Create Empty" option in the Hierarchy column to create an empty object, and name it "Crane Top". Move the empty object so that it is located at the center of the intersection plane of the tower arm and the tower body of the tower crane model, which serves as the rotation axis of the tower arm. Change the parent-child relationship between "Crane Top" and the tower arm model to make it the parent object of the tower arm.

[0042] Next, construct the hook component. Extract the hook model from the free "Hook" asset in the UnityAsset Store and import it into the current Unity project. Change the name of the hook model to "Hook" in the Unity Hierarchy page and drag it into the "Crane Top" module as a child of "Crane Top". Change the position of the hook so that it is at the end of the tower arm, and use the Transform's Rotation component to rotate the hook's direction.

[0043] Then add a rope component to the hook module (Inspector->Add Components->Line Renderer), click "Width" to set the rope width to 0.2, and select "Materials" to set a black material for the rope. The LineRenderer component also needs to set the start and end points. The start point is at the hook position, and the end point is at the tower arm trolley position.

[0044] Finally, create another empty object and rename it "SupplyHoldPosition", and place it as a child of "Hook" 0.5m below the hook, so that subsequent loads can interact with the hook.

[0045] Next, write and generate C# code classes. Create a "CraneMovement" script to control the tower crane's three degrees of freedom of movement: tower arm rotation, hook lifting, and trolley amplitude adjustment. First, create variables "turnSpeed", "hookVerticalSpeed", and "hookHorizontalSpeed" for the three degrees of freedom of movement speed, and assign values ​​to these variables in subsequent chapters. Then create four float type variables "hookRaiseLimit", "hookLowerLimit", "hookForwardsLimit", and "hookBackwardsLImit" to represent "hook lifting limit height", "hook lowering limit height", "trolley forward limit distance", and "trolley backward limit distance" respectively, to limit the range of motion of the tower crane hook in each dimension.

[0046] The "LowerHook" and "RaiseHook" functions are declared to control the lifting and lowering operations of the tower crane hook. Check the "PositionY" (the value of the y-axis in the local coordinate system) of the hook in the local coordinate system to ensure that it is between the lowering limit height "hookLowerLimit" and the lifting limit height "hookRaiseLimit". The purpose of this setting is to prevent the hook from exceeding the specified movement range. Similarly, the functions "TurnClockwise" and "TurnAntiClockwise" are declared to control the clockwise and counterclockwise rotation of the tower arm. The functions "MoveForward" and "MoveBackwards" are declared to control the forward and backward amplitude movement of the trolley. Call them cyclically in void Update, and control the movement of the three degrees of freedom of the tower crane through keyboard operations to complete the construction of the dynamic model of the tower crane.

[0047] In the virtual environment tower crane cab, first add the "Camera Rig" component of SteamVR and set the relevant parameters according to the tower crane driver's viewing angle height to define the tower crane driver's viewing angle in the virtual environment, including the position and orientation of the head. Next, select Edit->Project Settings->Input Manager in the top toolbar of Unity, and add three new axes to the joystick, named "HookVertical", "HookHorizontal" and "Rotation", corresponding to the movement of the tower crane in three degrees of freedom. Configure the parameters of these axes to match the input of the T.16000M joystick, and set "Type" to "JoystickAxis". According to the function of the tower crane joystick (for example, the x-axis of the left-hand joystick controls the rotation of the tower crane, the y-axis controls the amplitude change of the trolley, and the y-axis of the right-hand joystick controls the lifting of the hook), map the axes of the T.16000M joystick to the corresponding axes in the Input Manager.

[0048] Next, connect the power supply of accessories such as the base station and streaming box to ensure that the head-mounted display is working properly, and connect the T.16000M joystick to change the key control of the tower crane model in Unity to axis control. To support multi-person collaborative work, it is necessary to add network functions to the virtual environment to allow multiple users to operate different tower cranes in the same virtual construction site. Through the network tools in Unity (such as Photon or Mirror, etc.), configure the connection of multiple clients so that each user can independently control their own tower crane, while synchronizing the operating status of other tower cranes in real time to ensure the smooth progress of collaborative work.

[0049] Step 4: Design of multi-crane collaborative working environment

[0050] Through BIM (Building Information Modeling) technology, a virtual construction site environment is created in Unity to simulate the tower crane operation area, buildings, obstacles, and multi-tower crane operation scenarios. Set up multiple tower crane models and configure the relative positions, boom lengths, and operating ranges of the tower cranes according to the layout of the real construction site.

[0051] The terrain model is used to construct the terrain features of the virtual construction site environment to make it closer to the real construction site. The model is carefully set in terms of ground details, terrain height difference, material simulation, etc. to enhance the realism and immersion of the virtual environment. In the Unity editor, use the "Terrain" component to add a terrain object. Set the size of the terrain to the corresponding size according to the actual project requirements and the maximum visible range of the tower crane. Then use the "Raise&LowerTerrain" function in the "Terrain" component to edit the height of the construction site terrain and simulate the terrain features of the construction site. Finally, add materials and textures to the terrain, including soil, rocks, etc., to more realistically simulate the surface conditions of the construction site.

[0052] The building model includes various construction buildings and structures, including foundations, columns, floor slabs, etc., accurately restores the geometric shape and material properties of the construction project, and enhances the realism and spatial perception of the scene. Set up various buildings on the simulated construction site (such as scaffolding. In the Unity editor, use "Game Object" > "3DObject" > "Cube" to build a cube as the foundation of the building and the floor slab of each floor. Change the size of the cube by adjusting the "Scale" property in the "Transform" component and set its size to. Then use the "Cube" object to create and add columns and beams. The pillars serve as the vertical part of the entire frame structure, and the beams are connected to the top of each pillar. Finally, add concrete materials to all components, adjust the roughness and reflectivity of the material, etc. to achieve a realistic visual effect.

[0053] Step 5: Multi-person collaboration and task allocation

[0054] According to the actual task requirements of the construction site (such as carrying building materials, accurately lifting components, etc.), the operation tasks of multiple tower cranes are generated. Each tower crane undertakes different lifting tasks. Multi-person collaborative training is realized through Unity's network plug-ins (such as Photon or Mirror). Each trainee connects to the system through different clients and controls their own tower cranes respectively. Through the collaborative task configuration unit, the operation tasks of multiple tower cranes are dynamically allocated using genetic algorithms or set rules. The system allocates tasks to different tower cranes and optimizes them based on factors such as the load capacity, operation area and operation experience of the tower cranes. During the collaborative operation process, the system ensures the coordination of task allocation between the tower cranes through the management and dynamic adjustment of roles to avoid repeated operations or conflicts. When trainees perform multi-tower crane collaborative tasks, each tower crane not only operates according to its own tasks, but also needs to coordinate actions with other tower cranes. For example, when a tower crane lifts a heavy object, other tower cranes should avoid its operation area and maintain a suitable safety distance.

[0055] Step 6: Real-time operational control and feedback mechanism

[0056] The system conducts real-time monitoring and feedback during the lifting process. It uses sensors or collision detection functions in virtual reality to monitor the relative positions of the cranes in real time to ensure that a sufficient safety distance is maintained. When the system detects that the safety distance is insufficient, it automatically issues an alarm to prompt the operator to take action. The lifting path of each crane is dynamically adjusted according to the task allocation and the current operation status of the crane. Through collaborative path planning, it ensures that the operations of different cranes will not interfere with each other and avoid conflicts in cross-operation areas.

[0057] Step 7: Data recording and performance analysis

[0058] The system records the operation data of each trainee, such as the completion time, accuracy, operation trajectory, etc. of the lifting task. The operation data of each trainee will be automatically stored, and a detailed report will be provided after the training to evaluate the trainee's performance in multi-crane collaborative operations. Through data analysis, the system can evaluate the trainee's operation performance, such as operation accuracy, task completion time, and coordination of collaboration. The operation behavior is analyzed using methods such as principal component analysis (PCA), problems in the operation are identified, and suggestions for improvement are provided.

[0059] References:

[0060] [1] Liu Meng, Huang Chun, Wang Jingjing, Wang Wenqi, et al. Tower crane selection and layout optimization based on mixed integer linear programming[J]. Journal of Civil Engineering and Management, 2020, 37(02): 142-150.

[0061] [2]Fang,Y.,&Cho,YK(2017).Effectiveness analysis from a cognitiveperspective for a real-time safety assistance system for mobile crane lifting operations.Journal of Construction Engineering and Management,143(4),05016025.

[0062] [3] Al Hattab M, Zankoul E, Barakat M, et al. Crane overlap and operational flexibility: balancing utilization, duration, and safety [J]. Construction Innovation, 2018, 18(1): 43-63.

[0063] [4] Ye Yongjun, Zhang Xiaoyu, Zhang Yingpeng. Association rule mining and Bayesian modeling analysis of tower crane operation accidents[J]. Journal of Safety and Environment, 2024, 24(02): 610-616. DOI: 10.13637 / j.issn.1009-6094.2023.0092.

[0064] [5]Ali AH,Zayed T,Wang RD,et al.Tower crane safety technologies:Asynthesis ofacademic research and industry insights[J].Automation inConstruction,2024,163:105429.

[0065] [6]Li H, Chan G, Skitmore M. Multiuser virtual safety training system for towercrane dismantlement[J]. Journal of Computing in Civil Engineering, 2012, 26(5): 638-647.

Claims

1. A multi-tower crane collaborative driving training system based on virtual reality technology, used to train novice tower crane drivers in collaborative operation skills in complex working scenarios; characterized by: The system first uses the Unity engine to perform physical simulation on the tower crane's boom, hook, and rope key components to ensure that operational motion, load feedback, and collision response conform to actual physical rules. Subsequently, the virtual construction scene was constructed using the building information modeling technology BIM, and multiple tower crane models, construction site buildings, obstacles and cargo placement areas were configured to simulate the real construction site environment. The system also designed multi-tower crane collaborative operation tasks, including large-scale component handling, precise docking and obstacle avoidance, simulating the common collaborative needs of actual construction sites. Finally, the VR controller and tower crane simulation operation handle were integrated through the Unity engine to provide students with a first-person cockpit perspective and achieve real-time interaction in the virtual environment. Students used the handles to simultaneously control the boom rotation and hook lifting and lowering operations of their respective tower cranes to complete the set collaborative lifting tasks. After the task was completed, the system would record the student's operation data, evaluate key indicators such as operation accuracy, operation time and number of errors, and generate an operation report to help students identify and improve deficiencies, thereby improving training effectiveness. Through immersive virtual simulation, the system helps tower crane drivers efficiently master multi-tower crane collaborative operation skills, emergency handling capabilities, and communication and collaboration capabilities in a safe virtual environment, reducing training costs and safety risks and improving training quality, so as to be fully prepared for tower crane operations on actual construction sites.

2. A multi-tower crane collaborative driving training system based on virtual reality technology as claimed in claim 1, characterized in that: It includes physical simulation module, construction scene building module, multi-crane collaborative operation module and interaction and control module; The physical simulation module is used to realize accurate physical simulation of key components in tower crane operation, ensuring that the movement and feedback of the tower crane in the virtual environment can conform to the real physical laws; The construction scene building module is used to create a realistic virtual construction scene to simulate a real construction site environment and provide an immersive visual and operating experience for tower crane operation training; The multi-tower crane collaborative operation module is used to achieve coordinated operations between multiple tower cranes, so as to help trainees master collaborative operation skills in a virtual environment and improve their teamwork ability under complex construction site conditions; The interaction and control module is used to receive the operator's input instructions in real time and transmit them to the virtual tower crane to control various operations of the tower crane, and to provide real-time feedback on the movement status and operation results of the tower crane to ensure that the operator can obtain accurate feedback.

3. The multi-tower crane collaborative driving training system based on virtual reality technology as claimed in claim 1 is characterized in that: The physical simulation module includes a tower crane motion trajectory simulation module, which is used to perform motion simulation on the key components of the tower crane, such as the boom, hook, and rope, so that the rotation, extension, and lifting actions of each component conform to the actual physical laws, ensuring that the virtual operation is consistent with the real operation; The physical simulation module also includes a collision response unit for detecting collisions between the tower crane and obstacles or other tower cranes, and providing real-time feedback on collision results, so that novice tower crane drivers can perceive the physical reactions of collisions during simulated driving and learn to maintain a safe distance and perform correct avoidance operations.

4. The multi-tower crane collaborative driving training system based on virtual reality technology as claimed in claim 2 is characterized in that: The physical simulation module also includes a rope tension simulation unit for simulating the change of rope tension during lifting, moving and placing, providing a sense of rope tension at different heights, loads and motion states of the suspended object, and helping to familiarize oneself with the physical details in the control of the suspended object; The physical simulation module also includes an inertia effect simulation unit, which is used to simulate the inertia effect of the hoisted objects during acceleration, deceleration and rotation, making the dynamic effects of the movement and stop of the hoisted objects more realistic and cultivating students' ability to control inertia force; the above units are all built based on the Unity engine, and physical simulation is performed on the key parts of the tower crane's boom, hook and rope, so that the tower crane's motion trajectory, load force feedback and collision response conform to actual physical laws, so as to ensure the realism and accuracy of the operation.

5. The multi-tower crane collaborative driving training system based on virtual reality technology as claimed in claim 1 is characterized in that: The construction scene building module includes a construction site environment modeling unit, which is used to build a virtual construction site environment based on BIM technology, including the construction site topography, obstacles, and cargo placement areas, restore the real construction site layout and help familiarize yourself with the actual construction site.

6. The multi-tower crane collaborative driving training system based on virtual reality technology as claimed in claim 4 is characterized in that: The construction site environment modeling unit also includes a dynamic environment simulation, which is used to simulate lighting, weather, and wind speed environmental factors in the virtual construction site. By adjusting external conditions, the immersion and realism of the scene are enhanced to adapt to tower crane operations under different weather conditions.

7. The multi-tower crane cooperative driving training system based on virtual reality technology as claimed in claim 1 is characterized in that: The multi-tower crane collaborative operation module includes a task allocation unit, which is used to set a lifting task scenario in which multiple tower cranes participate together, including large component handling, precise docking, and object avoidance scenarios, simulating the multi-tower crane collaboration needs in a real construction site and improving team collaboration capabilities; The multi-tower crane collaborative operation module also includes a safety distance maintenance unit, which is used to monitor and prompt the safety distance between each tower crane in real time, prevent collisions between tower cranes, and provide warnings when approaching a dangerous distance, helping to cultivate safety distance awareness and correct avoidance skills in a intensive operation environment.

8. The multi-tower crane cooperative driving training system based on virtual reality technology as claimed in claim 6 is characterized in that: The task allocation unit also includes an operation priority setting, which sets priorities for the operation tasks of different roles so as to clarify the sequence of each operation step in the collaborative operation of multiple cranes; this module gives a certain role priority control at a specific task node to ensure that the task is completed in order according to the steps; The task assignment unit also includes a task instruction issuing function, which conveys the respective task requirements and instructions to the trainees through the system interface or voice prompts, and provides instant prompts or instruction updates during the task, so that the trainees can grasp the task progress and perform operations in real time to avoid operation conflicts or misoperations; The task allocation unit also includes a collaborative identification and indication function, which equips each tower crane and its trainees with collaborative identification of different colors or graphics so that trainees can quickly identify their respective roles and task division in the scene; at the same time, it provides a real-time diagram of the task progress or status, including the current position of the hoisted object and the angle of the crane arm, to enhance the visualization and accuracy of the operation.

9. The multi-tower crane collaborative driving training system based on virtual reality technology as claimed in claim 1, characterized in that: The interaction and control module includes a real-time operation control unit, which is used to integrate with the VR controller and the simulated operation handle through the Unity engine to achieve real-time control of the tower crane's boom rotation, hook lifting and lowering, and rope extension and retraction operations, ensuring that trainees can obtain a close to real operation experience in a virtual environment.

10. The multi-tower crane cooperative driving training system based on virtual reality technology as claimed in claim 8, characterized in that: The interaction and control module also includes a data recording and analysis unit, which is used to track the trainees' task completion status in real time, record the trainees' operation data during the execution of the lifting task, including key indicators such as operation accuracy, task completion time, and number of errors, and generate an operation report to facilitate data analysis and operation evaluation after training, and provide improvement suggestions for trainees.

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