Research On Digital Assembly Sequence Planning And Selective Assembly Of Marine Diesel Engine

The assembly is the last stage of the manufacturing process of marine diesel engine.However,the assembly cost of marine diesel engine is the highest in the manufacturing cost.The purpose of this paper is to improve the assembly efficiency,accuracy and reduce the assembly cost of marine diesel engine.At present,aiming at the study of the problem of incorrect,missing and interference assembly duo to the unreasonable assembly sequence,and short assembly plate problem duo to the whole assembly precision of the same parts in marine diesel engine.established the MBD assembly information model to meet the digital assembly sequence planning and parts matching of marine diesel engine,proposed the assembly sequence planning algorithm which based on improved ant colony algorithm and the same part selective assembly method based on the sorting and moving algorithm,and verified the feasibility and effectiveness of the algorithm by an example.Finally,according to the needs of the actual assembly production,each of the key technology are developed to be a software system.The main research work of this paper is as follows:(1)The assembly MBD information model as a unified data source for the assembly sequence planning and selecting assembly technology research,analyzed the MBD data structure of the assembly MBD model,established the assembly information model based on the information of assembly product,process and resource.And described the way how to express the product information in the product hierarchy tree.Finally,in order to reduce the computational redundancy,the assembly information model is simplified.(2)Proposed an automatic generation method of assembly sequence planning matrix,established a multi objective assembly sequence evaluation system for marine diesel engine assembly,constructed the automatic quantification function and the integrated index function,proposed an improved ant colony algorithm which is developed to solve the assembly sequence planning,and verified the feasibility and effectiveness of the algorithm by an example.(3)According to the requirement of assembling the same parts in the assembly process of marine diesel engine.established the optimization objective function which based on the whole assembly tolerance precision of the same assembly parts,and proposed a sorting and moving algorithm,the correctness of the algorithm is proved by examples,and the feasibility and effectiveness of the algorithm had been verified.(4)According to the requirements of actual assembly production,the prototype system has developed for the key technology,and the architecture and implementation steps of the prototype system are described in detail.