小麦植株拓扑结构发生过程的仿真研究

Research on Generating Process Simulation for Wheat Plant Topological Structure

以小麦作物为研究对象,采用小麦植株形态结构的观测分析,提出了由多层次自动机模型、植株拓扑结构数据模型和模型调度算法构成的小麦植株拓扑结构的发生过程仿真方法。多层次自动机模型将小麦植株拓扑结构的发展过程视为生长单元、叶元和器官三个不同层次基本结构的重复、迭代,并以此建立宏状态、子状态和微状态自动机,进行拓扑结构演变过程的控制和形式化描述;植株拓扑结构数据模型基于小麦分枝结构的特征,建立拓扑结构的抽象单元和抽象单元间的关系,实现植株拓扑结构的描述与结构化存储;模型调度算法以多层次自动机为控制机制,进行植株拓扑结构数据的动态更新。在此基础上,采用VC++/OpenGL建立小麦虚拟生长可视化系统,进行了植株拓扑结构发生过程仿真,结果表明,改进方法能够对小麦个体全生育期拓扑结构的演变过程进行准确仿真,与同类仿真方法相比较,具有拓扑发生规律形式化定义易于建模理解、拓扑结构发生仿真控制精确、拓扑控制与描述分离利于改进和扩展等特点,可为虚拟小麦生长研究提供技术支撑。

In this paper, using wheat crops as the research object, the wheat plant generating process simulation method was presented based on the observation and analysis of the wheat plant morphological structure, the method composes of muhi-scale automata model, plant topology data model and model scheduling algorithm. Treating the de- velopment process of wheat plant topological structure as the repetition and iterations of the three different level basic structures including the growth units, leaf elements and organs, the multi-scale automata model was use to establish the automata of macro state, substate and microstate. Moreover, the multi-scale automata model also was used to conduct the control and formalized description to the topology structure evolution process. Based on the branch struc- ture characteristics of wheat, through the establishment of the abstract units of the topological structure and the verti- cal and horizontal link relations between the abstract units, the plant topology data model achieved the description of the plant topology and the structured data storage. The model scheduling algorithm conducted the dynamic update of the plant topology data using the multi-scale automata as the control mechanism. Based on these, the virtual visual- ization system of the wheat growth was established using VC＋＋/OpenGL. The simulation of the plant topology genera- ting process was also conducted. The results show that, this method can simulate the evolution process of the individ- ual wheat plant topology in whole growth period accurately. Compared with the similar simulation method, this method possessed of the following characteristics. Firstly, the formalized definition of the topological occurrence regularity is easy to understand. Secondly, the topology occurrence simulation can be controlled accurately. Finally, the separa- tion of the topology control and description were beneficial to improve and expand. All in all, this method can provide the powerful technical support for the research on virtual wheat growth.