Research On Modeling And Contoller Method Of Schedule Planning In Building Construction

The construction schedule plan is carries out to organize all construction works with right logic and sequences under resources conditions. The purpose of schedule plan is to finish the project on schedule with quality guarantee. The making of schedule plan is huge system engineering because of the long duration, big investment, massed operations, and complex conditions. Therefore, it is necessary to find an approach which can describe construction proceeding with clearly and accurately models to analyze the overall static and dynamic characteristics of the system and to discover and overcome the fetal error of schedule plan before the construction start. On the other hand, the optimization and control of the plan are key problems in the proceeding of construction. Based on the modeling of the construction proceeding and given constraints, the information of construction can be processed, evaluated and the schedule plan can be corrected and optimized.This paper start from the characteristics of construction project, the hierarchy and highly coordinates of the construction schedule are analyzed. Based on the granularity and scale of management organizations, the hierarchies of network schedule and hierarchical network planning model of construction are established, the calculate methods of the parameters, critical path and topology of the network are given. Then, construction process and the modeling method of construction are analyzed in detail. The construction process is a kind of discrete event dynamic system (DEDS). The DEDS's characteristics of construction are researched, the requirements of construction process modeling are summarized, and the Petri net is determined as the tool to model construction process. Thus, the theoretical basis of this paper is completed.Based on the hierarchical network plan and the Petri Net, the construction process model is constructed. The process model and operation model constitute the schedule model and the relationships between them are described. The hierarchical network plan of construction based on the Time Petri Net, hierarchical place and task transition are defined, the correctness of above two models is analyzed based on the accessibility of Petri Net. Based on the Petri Net the operation model is established. The construction process described with Petri Net and the time's expressions in the Petri Net are researched. The operation model of construction is established thought the research of processes joint relationships.The method of schedule plan optimization is researched. According to the management of construction project in our country, the two-level network optimization model is established based on the HNPC model to satisfy the optimistic demands. The construction schedule optimizations under resource constraints and resource-leveling are researched, a solution strategy based on genetic algorithm and simulated annealing is presented. The excited sequence of transition is traded as population to be calculated, the Petri Net model and the algorithm are integrated.The method of construction schedule control is researched. The method of line of balance (LOB) is introduced into the field of schedule control, the application principles and steps are elaborated, the LOB method and schedule front line (SFL) are integrated to monitor the construction process, the recognition of SFL and countermeasures are described. According to the HNPC model, the characteristics of construction process are explained. The fuzzy dynamic programming method is introduced into the process control and the realization is presented.This paper systematic studies the theory and method of the construction schedule modeling and controlling. The system engineering, network plan, genetic algorithm and simulated annealing, fuzzy dynamic program are introduced to the field of modeling and controlling of construction schedule. The hierarchical network model is presented, the process and operation models are established, the method of optimization of schedule plan is researched, and the method of construction schedule control is improved.