基于Petri网模型的收获机轴流式脱分选装置参数化设计

为实现设计的快速化和规范化,进行了基于喂入量变化的联合收获机轴流式脱分选装置的参数化设计研究。通过建立喂入量与相关设计参数的数学模型,获得可用于参数化设计的各个参数。在分析参数之间层次关系和依赖关系的基础上,利用Petri网模型、通过参数传递构建了简化设计的计算机模型并开发了设计平台。应用结果表明:当在程序界面中输入喂入量并选择相关数据后,能自动生成各种所需的结构参数(栅格式凹板包围面积、清选筛面积、脱粒滚筒齿数)以及工作参数(风量、功率);将某部件所得结构参数输入UG环境平台,可获得该部件的三维设计图样。经与现有成熟机型脱分选装置结构参数和工作参数比较可知,计算机模型生成的设计参数和工作参数规范,获得的三维图样符合设计要求。参数化设计平台不但可以进行脱分选装置的规范化设计、提高设计效率,还可以快速判别、修正现有机型脱分选装置的设计参数。

Parametric Design for Axial Flow Threshing-Separating-Cleaning Unit Based on Petri Model

To support rapid design of an axial flow threshing-separating-cleaning unit of combine harvester, a formal methodology, which is a parametric approach based on the throughput was proposed. By building a mathematical model to establish the relationship between the throughput and the related data, the parameters of parametric design can be obtained. On the basis of analysis of the hierarchical relationship and dependency between the parameters, a computer platform was developed to realize the simplified design by using the Petri net model to solve the complicated parameter transfer structure. The results showed that the system can automatically generate the required structural parameters (e.g., area of crosswise axial-flow threshing unit grate-type concave and area of longitudinal axial-flow threshing unit grate-type concave, area of scales sieve and area of shutters scales sieve, finger-tooth quantity of whole-feeding axial-flow threshing cylinder and finger-tooth quantity of head-feed threshing cylinder) and relevant working parameters (e.g. air volume and power ) for a given throughput and some relevant data. By importing the result parameters into UG environment, the 3D model of the component can be reconstructed with these parameters. According to data comparison with the developed products, the design parameters of the computer model were accurate and reliable, and 3D model met the design requirements. Parametric design platform not only can carry out the standardized series design and improve the design efficiency, but also can help quickly refine the parameters of the existing products.