A Combination Of Qualitative And Quantitative Method Of Modeling And Simulation

With the rapid development of science and technology and the interaction between all kinds ofknowledge, complex systems have been widely used in various aspects, such as aerospace, militarysimulation and other areas. Complex systems are increasingly showing uncertainty characteristics, andexisting modeling methods are difficult to sufficiently describe the uncertainty information and do nothave a unified standard. Therefore, it is necessary to study a kind of standard unified modelingmethod that can describe the uncertainty information and a corresponding simulation method. Thispaper has studied the related theories and algorithms, such as Unified Modeling Language, qualitativeand quantitative modeling and simulation methods, specific work is as follows:Firstly, a qualitative and quantitative unified modeling approach (Q2UML) was presented. Basedon the Unified Modeling Language (UML), it combined qualitative simulation theories and redefinedor extended the component diagram, sequence diagram and state diagram to ensure the correctness ofQ2UML. The corresponding symbolic definitions were given and the expanding contents andgraphical modeling methods were described in detail. The missile pressure machine was put as themodeled object to achieve qualitative and quantitative unified modeling of complex systems.Secondly, in order to verify the correctness of Q2UML models, a static and dynamic conformanceverification method was proposed. The static consistency checking algorithm which put componentdiagram as a reference to detect the static elements of sequence diagram and state diagram validatedthe static consistency between models. By validating the pneumatic machine model, we demonstratedthe effectiveness of the algorithm. With SPIN being used to validate the dynamic consistency ofmodels, the transformation rules of Q2UML sequence diagrams, state diagrams, and constraintrelations of parameters to Promela, and LTL formulas to describe the nature of system were given,. Byvalidating the air pressure machine models, experimental results showed that the method was not onlyeffective, but also reducing the redundancy status in validation process, improve validate efficiency.Then, a partial enlarged qualitative and quantitative simulation algorithm (PEQ2S) was presented,which was based on Q2UML. This algorithm made use of qualitative and quantitative state descriptionmethod which included slope value to express the rate of variables change; It presented a method ofdisseminating gradient quantitative information on the basis of slope direction; And, it come up withstep refined method which conducted local amplification to the important point to improve the localaccuracy and reduce simulation time. Experimental results indicated that PEQ2S posed a highperformance of prediction and time-saving.Finally, missile attack system was modeled and simulated based on Q2UML and PEQ2S. Theunified models of qualitative model quantitative models were constructed by Q2UML. Based onPEQ2S by enlarging important points locally，the qualitative and quantitative scheduling methodimproved the local accuracy and reduced the simulation time. Simulation results showed that thequalitative and quantitative scheduler was time-saving than the time scheduler and higher precisionthan the event scheduler.