Research On Motion Planning And Rapid Emplacement Of Tower Crane Based On Prefabricated Building

Construction industrialization has been widely valued and vigorously developed in China because of its high efficiency,high economic efficiency,low resource consumption,green environmental protection and other characteristics.Among them,prefabricated building is an important development direction of construction industrialization,which has become the direction of transformation of China's construction industry during the 13 th Five Year Plan period.This paper is a study on "automatic planning and locating of hoisting path of components" which is a sub topic of "key technology and equipment for efficient hoisting and installation of components in construction site".The main content is that after considering the flexible deformation of the tower crane,the hoisting components can move according to the pre planned motion curve and get the driving curves of the three driving mechanisms of the tower crane.In this paper,the analytical formulas of inverse kinematics and inverse dynamics under the multi rigid body model of tower crane are derived as the theoretical basis for the motion planning of tower crane.By using the improved artificial potential field method and a tension algorithm,the three-dimensional global path planning and zigzag path optimization of tower crane are carried out,in which the obstacle model is simplified as the minimum envelope cylinder.On this basis,B-spline smoothing is applied to the path,and the motion function of the hoisting component is constructed by using the parameter equation.After the tower body and boom are simplified as cantilever beam model,a path correction method considering the deformation of the whole structure is proposed.Focusing on the construction mode of component motion function,aiming at three groups of optimization models,namely,driving mechanism power,speed,swing angle and time,which are paid more attention to in practical work,multi-objective evolutionary algorithm is used to optimize the component motion function,and the Pareto optimal frontier corresponding to the working condition is obtained.Combined with the commercial software ANSYS and Adams,the simplified model and a real rigid flexible coupling model of the flat head tower crane are established.Firstly,the correctness of the inverse kinematics and inverse dynamics formula is verified by the mechanism motion simulation,and then the correctness of the theoretical derivation of the lifting path correction in the lifting plane of the simplified model is verified.Finally,the correction method is extended to the path correction of the real tower crane in threedimensional space,then the applicability and reliability of the path correction method to the complex model is verified.