自修改Petri网及其P-线性不变量

自修改网是７０年代末问世的一种拓广的Ｐｅｔｒｉ网，但迄今为止自修改网还没有一个规范的数学模型．本文米用了矩阵及向量的方式对自修改网的模型、点火规则以及其位置线性不变量进行了规范的数学定义；并从可达集的角度讨论了位置／转移网与自修改网之间的关系；通过求解齐次线性方程组族，给出了求位置线性不变量的一个充分必要条件．最后，通过一个实例说明了其优于位置／转移网之处．

Self Modifying Nets and Its Place Linear Invariant

Valk in 1978 suggested the'idea of self modifying(SM)net[2].The author worked on SM net underValk's supervision in 1990-91 to convert his idea into a rigorous mathematical formulation that is verylikely to be useful in engineering applicatiolls.The model and firing rule of SM net and its place linearinvariant are expressed in terms of rnatriccs and vectors.From the view point of reachability set the relahonship between p/ T net and SM net is discussed. Through solving homogeneous linear equations,theauthor obtains the necessary and sufficient condition for the cxistence of place linear invariant,wbich canthen be obtained.Finally,an example is given to'show the practical application of SM net.