为了通过云制造服务实现对制造资源能力的精准调度与使用,云制造模式要求制造资源的虚拟化过程必须保证云制造服务所描述的相关能力与原制造资源所提供的能力在逻辑上具备严格的一致性.为此,提出了基于同态映射的制造资源虚拟化机制:通过在物理资源层和云服务层之间定义抽象的虚拟能力层,在解耦物理资源与云服务之间直接映射的同时,分别定义了制造资源-虚拟能力、虚拟能力-云服务的同态映射函数;采用基于语义相等映射的实现原理,将物理资源的能力及其所需的依赖条件进行同态抽象转换,并通过初步的案例仿真说明制造资源在同态映射过程中保持了能力语义的不变性.
Rather than trying to tie together manufacturing resources for the purpose of creating an aggregated application to perform, cloud manufacturing seeks to aggregate manufacturing resources from various distributed manufacturing entities into a virtual pool of resources by using virtualization technique, and to expose manufacturing resources as a set of services that resources consuming applications and organizations can combine in any arbitrary fashion. To ensure precisely scheduling and using of the capabilities provided by manufacturing resources through cloud manufacturing services invocation, it requires the virtualization process from manufacturing resource to cloud manufacturing service must guarantee the capacity described by cloud manufacturing service is strictly consistent with the original one provided by the relevant manufacturing resource. In this context, a homomorphic mapping based virtualization mechanism for manufacturing resource is proposed, which is built on a three-layer model including physical resource layer, virtual capability layer and cloud service layer. On the basis of the decoupling of the direct mapping between physical resources and cloud services via establishing virtual capability layer, the mechanism meets the requirements of virtualization process by defining two homomorphic mappings: mapping between physical resource and virtual capability, and mapping between virtual capability and cloud service. The discussion is made from case demonstration to provide invarlance service evidence of the benefits from homomorphic mapping in the context for the virtualization process and ensuring the validity and reliability of of keeping mapping cloud manufacturing service.