| Busbar plays an important role in the high/low voltage distribution system in modern buildings.At present,most of the busbar systems were manually designed on some 2D CAD platforms.With the introduction and popularization of the Building Information Modeling(BIM),the whole building models are highly digitalized.The current way of designing busbar cannot meet the growing requirements of BIM on the information integration and design automation.Aiming to solving problems in the busbar designing,this paper focused on the key technologies for the 3D busbar design on BIM platform.Two algorithms were proposed for busbar automatic layout and segmentation and an automation busbar designing software based these two algorithms was developed that covering the entire process from layout design to BOM generation.Application of this design software will greatly automate the process of busbar designing and help the busbar manufacture industry develop with booming BIM technology.The main research work of this paper is summarized as follows:(1)A framework of busbar automatic designing system on Revit platform was proposed by analyzing the current ways of busbar designing process and main problems for the development of BIM technology.(2)A new busbar automatic layout algorithm was proposed and implemented to solve the problems in real busbar industry.It was based on the Rapidly-exploring Random Trees(RRT*)algorithm.A special expanding strategy,called corner point expanding,was proposed to avoid random expanding in original RRT* algorithm,so that the generated busbar routes are composed of straight lines.In addition,a greedy algorithm is used to further optimize the busbar routes to minimize the total segment length and the quantity of elbows used satisfy the constraint of the facing direction of the busbar.Finally,the feasibility of the algorithm is verified by comparing and analyzing the simulation results with the RRT* and BRRT* algorithm(3)A multi-objective optimization mathematical model for busbar automatic segment was proposed.In this model,the variables and constraints were defined according to the requirements of busbar installation and manufacturing.A new multi-objective optimization algorithm based on the NSGA-II algorithm was proposed to solve busbar segment problem.The new algorithm localized the mutation of decision variables into one busbar segment in one step.It is helpful to avoid falling into local optimal solution and insufficient population diversity in dealing with two some conflicting goals: the maximum standard length and the minimum non-standard elbow.The calculation results and the comparison with related algorithms showed that the proposed algorithm has certain advantages in terms of the quality and diversity of feasible solutions.(4)To verify and implement the above algorithms in real industry,an automatic busbar design system was developed using C# programming language and the APIs provided by Revit platform.The system covers the complete busbar design process from layout design to BOM generation.This system establishes busbar layout environment by obtaining the geometric data of buildings and obstacles from the Revit model,and then realize the automatic busbar layout and segmentation by using the above mentioned algorithms on the BIM platform.The design results are presented in Revit by family instances and the BOM can also be output by using the Revit standard functions. |
