Research On Construction Service Composition Under The Environment Of Internet Plus

In the era of global competition,the construction industry needs to change the status quo of low production efficiency and difficult cooperation through industrial upgrading to enhance industrial competitiveness.The action plan of Internet Plus is deeply affecting all walks if life,and it also brings opportunities for the transformation and upgrading of the construction industruy.With the rise of Internet platform economy,scholars realized that the construction platform mode will become an inevitable trend in the transformation and upgrading of the construction industry.The prerequisites for the realization of the cosntruction platform include the servitization of construction and the virtualization of construction services.On this basis,construction takes the form of an organic combination of a series of construction services provided by different construction participants.However,construction platform is still a new thing in the field of construction management,research work concerning construction service and service composition is relatively lacking.In order to provide theoretical support for the realization of the construction platform mode,this paper aims to address some issues related to construction service,service network generation and service composition on the basis of ontology modeling,artificial intelligence planning and intelligent optimization.Primary work and contributions are summarized as follows.Considering the need of clear understanding of construction service for the servitization of construction,this paper provides a specific definition of construction service based on the analysis of service characteristics of construction process,and then analyzes the connotation of construction service from the perspective of service transaction.In addition,this paper provides a classification framework of construction service,summarizes the basic attributes of construction services,constructs an ontology model of construction service and introduces the way to encapsulate construction services such as to enable their interoperability on the construction platform.Service bidding based on the construction service network is more conducive to overall time and cost control.Considering the possible isomeric and coupling relationship between construction services,this paper proposes an HTN(hierarchical task network)planning based approach to generate construction service network.The approach adopts the depth-first traversal search to generate a branching plan for different services with isomeric relationship,and finally forms an construction service network with branches.In order to avoid unnecessary repetitive planning,this paper also designs a branch merging mechanism based on the equivalence of planning nodes to improve the efficiency of the approach.The final case analysis also verifies the effectiveness of the branch merging mechanism.The selection of service providers based on the construction service network needs to consider the deadlines and cost optimization.In the face of increasing large-scale construction projects,this paper proposes a meta-heuristic based optimization method for service provider selection.Based on the symbiotic organisms search(SOS)algorithm,the method utilize the mode list to represent discrete decision variables,designs a new transfer function to discretize the continuous variables generated in the calculation process.Meanwhile,a heuristic mutation operator based on network structure is designed to enhance the ability to cope with large-scale network.Finally,the effectiveness of the proposed discrete SOS algorithm is demonstrated by comparing with the meta-heuristic method with respect to the same problem in the literature,and the effectiveness of the heuristic mutation operator is also verified by self-constrast.Under the mode of agency transaction,construction service composition needs to consider the generation of the service network and the selection of the service provider simultaneously.Considering the impact of deadline and budget constraint on the process,this paper proposes an HTN planning based approach for construction service planning and scheduling.The approach extends the formalism of traditional HTN planning to represent the problem as an HTN planning problem,uses temporal reasoning technique to obtain temporal relationships between construction services to avoid unnecessary sequence constraints.At the same time,a backtracking evasion mechanism is devised to avoid the backtracking caused by premature selection of service providers to improve planning efficiency.The final case analysis shows that the proposed planning approach can generate different service compositon plan according to different deadline and budget constraints.It also verifies the effectiveness of the backtracking evasion mechanism by comparing the planning time on a series of fictional problems.