Research On IMU-based Wireless Positioning Method Of Prefabricated Components

At present,the development of prefabricated buildings is inextricably bound up with BIM technology.However,for traditional methods of reconstructing 3D models,there are some disadvantages,such as lack of uncovered building components or semantic information,and these methods are not specifically applied for prefabricated buildings.Therefore,a selforganized modeling method for prefabricated buildings is proposed in this paper,considering the characteristic that building components are prefabricated in factories and then transported to the construction site for assembling.The core idea is that three-dimensional models of prefabricated buildings are automatically generated according to the actual position of prefabricated components measured by sensors.Models generated using this method are more accurate and efficient,and can be used to promote construction management.One of the key technologies is wireless positioning of prefabricated components,which will overcome the shortcomings of previous methods using wire transmission.Firstly,the appropriate technologies of positioning and mobile communication are determined by comparing different alternatives.Then,the wireless positioning scenario is studied,including a self-organized modeling system,the coding method of prefabricated components and a wireless positioning device.Following work is carried out: a modularized self-organized modeling system is built with an IMU-based wireless device and a remote monitoring center containing a data processing unit,a database and a modeling platform.Also,this paper analyzes the modeling process by using business process modeling notation.The work flow involves three parts: the factory for prefabrication,the construction site and the remote monitoring center.The coding method is designed to express prefabricated components’ attribute information and to recognize their identities.Further,the positioning principle of prefabricated components is studied.Firstly,error sources are analyzed and the elimination algorithm is studied.The quaternion-based algorithm and quadratic time-domain-integration-based algorithm are developed for the attitude angle and displacement calculation,respectively.The building information model can be automatically generated according to the final position of components.Finally,a practical case is presented to demonstrate the feasibility of this method.In this case,the relative error of displacement and attitude angle is about 5% and within4% respectively,which basically meets the requirements of engineering precision.