Research On Modeling For Tower Crane Virtual Operating System

Tower crane has been widely used in construction site because of the higher lifting and wider coverage characteristics, but the training of pilots for tower crane has many problems, such as poor security, long cycle, high cost, etc. Visual simulation of tower cranes can be used as an important tool in driving training, because it has many remarkable characteristics such as high security, good recurrence, strong exploration, etc. Therefore, the studying and developing of the visual simulation system for cranes has also been an important development direction in recent years.The modeling and driving is the most important work for the development of visual simulation. As for researching and developing the visual simulation system of tower cranes, it must offer the virtual driving environment to the driver to make them have a strong immersed sense. This topic took the tower crane and its surrounding environment as the background and took the tower cranes as the research object. The paper carried out the study at aspect of the complicated modeling, the virtual scene designing, the real-time optimization and the system realizing, etc to develop a desktop visual simulation system and realize the real-time visual simulation of tower cranes successfully. The main research contents are as follows:(1) Based on the theory analysis of simulation modeling technology, combined with the structure of tower crane and the characteristic of construction site, this paper chose the professional visual simulation modeling software Multigen Creator and put up the method of scene modeling, especially focused on the technology of scene modeling. The paper proposed the3D virtual scene modeling optimization technology from the aspect of structure optimizing and modeling optimizing, and created the construction site and surrounding environment of tower crane. It enhanced the fidelity of virtual environments and improved the real-time rendering and response speed of the system.(2) By analyzing the moving characteristics of tower crane, dynamic model of tower crane was set up. Also, this paper simulated the hoisting, slewing, derricking motions and load oscillating on tower cranes successfully based on VC++platform, and used time-delay filter theory, which could restrain the load oscillation, to simulate the operation without load swing, and it enhanced the fidelity of virtual operation. Finally, the system was realized successfully on the base of the rendering technology of three-dimensional scene of visual simulation driver software Vega, which could display scene, wander real-timely, drive model, control real-timely, and simulate the natural phenomena, and so on.(3) Tower crane and cargo could collide with scene during their movement, so the collision detection method of Vega was adopted in this paper to realize the collision detection of tower crane, and realized the collision response after the collision detection by programming to restrict the movement of tower crane and cargo. This solved the distortion of the hook and cargo across the ground and wall when tower crane was moving, which reflected the natural interaction between the user and the virtual scene.