Research And Implementation Of Algebraic Loop Analytical Method In FMI Simulation System

With the increasing demand for modeling and simulation technology in various fields,multi-domain distributed joint simulation systems are widely used.Among them,the simulation platform with FMI joint simulation standard as the underlying technical standard is highly recognized by the industry.In this paper,we analyze and study the most important algebraic loop problem in the joint simulation system,namely nested algebraic loops,based on the FMI joint simulation system,and solve the problem that the simulation modules cannot transfer data due to the timing of each module in the communication,and at the same time improve the operation efficiency of the analysis method of nested algebraic loops,and apply the method to the actual FMI simulation system.Firstly,this paper elaborates the important position of complex joint simulation engineering in production life,and then introduces the FMI joint simulation standard.Through the study of FMI standard and FMU model structure,we understand the causes of nested algebraic loops in complex joint simulation engineering,which leads to the focus of this paper,that is,the problem of nested loops in data transmission in simulation task modules.Second,this paper analyzes the nested algebraic loop structure and transforms the detection problem of nested algebraic loops into a strongly connected component finding problem through the knowledge of graph theory in mathematics.Since a single strong connected component detection algorithm cannot find all the loops,this paper mainly combines Kosaraju algorithm and breadth search method to construct Kosaraju-broadness bi-directional method to find all the loops of the joint simulation system by retrieving the control information between each joint simulation module;for the retrieved loops,numerical analysis knowledge is introduced to transform them into mathematical The problem of solving the nonlinear system of equations is solved by using the current Newton-NPHSS iterative method constructed from the inexact Newton method and the NPHSS iterative method to solve the nonlinear system of equations,so as to obtain simulation data satisfying the expected results.Finally,the whole nested algebraic ring resolution method is optimized by multiple processes to improve the simulation efficiency and reduce the simulation time.The optimized nested algebraic ring resolution method is also integrated into the FMI joint simulation system to solve the communication deadlock problem caused by nested algebraic rings in the system.The experimental results verify the effectiveness of the Kosaraju-extensive bidirectional method for detecting nested algebraic loops in the system and the accuracy of the Newton-NPHSS iterative method for solving nonlinear systems of equations,which are of great significance for the development of the joint simulation system.