| In recent years,cloud manufacturing has brought opportunities to the manufacturing industry,but also brought some challenges.Under the cloud manufacturing mode,with the cloudization of massive manufacturing resources and the explosive growth of user demands,more and more cloud manufacturing services and manufacturing tasks are published on the cloud manufacturing platform,which requires higher and higher security and manufacturing efficiency of the platform.Blockchain is highly secure,tamper-evident and distributed.The integration of blockchain technology into cloud manufacturing to enhance the efficiency and extend the functionality of cloud manufacturing has become an important research topic in cloud manufacturing.However,most of the current research on blockchain-based cloud manufacturing is focused on trust mechanism optimization and security performance enhancement of cloud manufacturing platform,while less research is conducted on cloud manufacturing efficiency enhancement,comprehensive evaluation,data storage and other issues.For this reason,this paper is based on blockchain technology to investigate the methodology,evaluation,storage and consensus of the traditional cloud manufacturing service selection process,and the main research contents are as follows.(1)Based on blockchain technology,a decentralized method for cloud manufacturing service selection is proposed.Using blockchain as the basic component to design the cloud manufacturing service selection framework and process respectively,the process of cloud manufacturing service selection is transferred from the central server cluster to the computing nodes in the blockchain network in order to decentralize the source of computility and accelerate the speed of cloud manufacturing service selection while reducing the hardware requirements of the cloud manufacturing service selection platform.(2)Based on subjective and objective weight analysis technology and node credibility analysis strategy,a comprehensive evaluation method is proposed for cloud manufacturing service selection results.Firstly,the subjective and objective analysis of cloud manufacturing services is carried out based on the subjective preferences of users and the quality of service attribute values of cloud manufacturing services.Secondly,based on the behaviors of nodes in the blockchain network,the node credibility is calculated,and the credibility is added to the comprehensive evaluation of the cloud manufacturing service selection results by a certain percentage.Finally,this comprehensive evaluation method is used to verify the improvement of the merit-seeking capability of the technology proposed in this paper.The validation results show that the quality of the selection results of the cloud manufacturing service selection technology based on blockchain is much better than that of the traditional cloud manufacturing service selection technology.(3)To address the storage problem of key data in the cloud manufacturing service selection process,a tri-chain blockchain data storage model is proposed to solve the problem that contract data,delivery data and credibility data cannot be stored together due to different storage time dimensions.In addition,the Practical Byzantine Fault Tolerance(PBFT)algorithm in the contract block consensus process is improved using a strategy of shrinking the consensus node cluster and simplifying the consistency protocol to be applicable to blockchain-based cloud manufacturing service selection technology,while significantly improving consensus efficiency and reducing communication costs.This paper improves the traditional cloud manufacturing service selection technology based on blockchain from multiple perspectives to address the problems of insufficient computility and lack of real-time data due to the proliferation of data and data silos.Empirical analysis shows that the technology can speed up the cloud manufacturing service selection while improving the quality of the selection results,ensure the security,real-time and transparency of key data storage in the cloud manufacturing service selection process,significantly reduce the communication cost of the process and enhance the user experience. |
