Research On Safety Situation Evaluation Of Construction Worker Trajectory Based On Real-time Positioning

Currently,the overall safety production situation in China’s construction industry still faces severe challenges,and on-site safety accidents occur from time to time.As one of the main participating factors in construction activities,construction workers are highly vulnerable to threats to the safety of life and property on the one hand,and their unsafe behaviors are an important cause of accidents on the other hand,so safety management has always been a hot spot in research.At the same time,with the continuous advancement of technology,the application level of information means,mobile technology,real-time positioning technology and intelligent wearable devices in the engineering construction stage has been continuously improved,and the intelligent safety management model has emerged.Based on this background,in order to enhance the perception of the personalized unsafe behavior of construction workers,and then improve the level of safety management and control on the construction site.From the perspective of individual construction workers,this thesis combines real-time positioning technology and BIM technology to carry out the research on the safety situation of worker trajectory behavior.First conducts a grading study of hazardous areas,then designs experiments to collect workers’ historical trajectories,and considers safety to characterize the behavior characteristics of worker trajectories,and then establishes a safety evaluation model of worker trajectory behavior situation through fuzzy evaluation and neural network,and finally constructs a construction site personnel positioning management system.The specific research content is as follows:(1)The knowledge graph,LEC method and four-color differentiation technology were used to establish the zoning and grading rules of construction hazardous areas.Firstly,the accident cases are handled through the knowledge graph theory,the relationship triad is established,and the typical hazard sources such as deep foundation pits,scaffolding,and tower cranes on the construction site are excavated by using visualization tools.Then a safety evaluation expert group was formed,and the LEC method was used to divide the hazard sources into five hazard levels.Finally,according to the four-color differentiation technology,the construction space is divided into 12 danger areas,and the expression methods of different types of danger areas are determined by combining BIM technology.(2)The set of trajectory feature parameters is established through real-time positioning and computer technology.Design trajectory data acquisition experiments,consider positioning accuracy,use GPS positioning outdoors,Bluetooth positioning indoors,and collect historical trajectory data of workers.Combined with the actual and documentary data,considering the safety of personnel movement,the trajectory behavior characteristics of six aspects of the speed of the danger area,the standard deviation of speed,the residence time of the danger area,the crossing frequency,the proximity distance and the complexity of the environment in the danger area were described,and Computer technology is used to calculate the characteristic data parameters of each worker’s movement trajectory.(3)The safety evaluation model of worker trajectory behavior situation was established by fuzzy neural network.Firstly,the evaluation index is established according to the trajectory characteristics,and the weight of each index is determined by the entropy weight method.Then,after the fuzzy comprehensive evaluation method pretreated the trajectory samples;The trajectory situation is divided into four safety levels: very low,low,medium and high,and finally the six characteristic parameters of the trajectory sample are taken as input and the four safety levels are used as output,which are put into the fuzzy neural network for training and the evaluation model is obtained.(4)Combine BIM technology and real-time positioning technology to establish a construction site personnel positioning management system.Firstly,the functional analysis of the system is carried out,the requirements of visualization and early warning functions are determined,and the four core function implementation principles of automatic hazard four-color hierarchical visualization in the main danger area,positioning and monitoring database established by SQL server,early warning of personnel intrusion into the danger area and personnel trajectory behavior situation determination and analysis are introduced.Then build the system framework and design four functional modules of area monitoring,real-time monitoring,alarm viewing and behavior analysis.Finally,combined with one case,the application effect of the system is analyzed.This study supplements and explains the existing theoretical system of hazardous area division and identification of construction sites,provides a safety evaluation method for worker trajectory behavior situation,and establishes an intelligent worker trajectory situation assessment system,aiming to provide new construction safety management ideas and approaches for the safety management of construction enterprises,reduce accidents caused by human factors,and effectively improve the efficiency of site safety management.The thesis has 53 figures,35 tables,and 111 references.