Disassembly Process Planning And Evaluation Of Product Parts

Disassembly of scrap product is a necessary procedure of product's recycling and reusing, which is an important part of whole life cycle of the products. Scrap product disassembly process planning can reduce the cost of disassembly operation. It can also improve operation efficiency and the enterprise competitiveness. The disassembly process planning has become the core of international industrial field research. It has caught extensive attention by social sectors and related research institutes.In this dissertation, selectivity disassembly sequence planning and evaluation are studied. A new efficiency method is tried to seek, which is combined with graph model and heuristic algorithm. It is used to solve the key problem of disassembly planning. The influences on disassembly in engineering are discussed. The reasonable disassembly planning can make positive contribution to recycling and reusing. The necessary conditions for available disassembly sequence are summarized. They can provide a new thought for the research on disassembly sequence planning.The experience and achievement of domestic and foreign related fields is synthesized. Disassembly modeling methods, disassembly solving methods and disassembly sequence evaluation method are deeply studied. There are logical relations and interdependences in these problems. The whole disassembly planning process can be finished with solution of these problems in turn.Application situation, advantages and disadvantages of some classical disassembly modeling methods are investigated. Aim at the feature of selectivity disassembly, a new disassembly modeling method is proposed based on weighted blocking graph model. The process of fulfilling product weighted blocking graph model is a process of collecting relevant product's data & logic operation. In this process, determination of constraint and blocking relations is the main work, which is vital to disassembly feasibility of parts in weighted blocking graph. According to this model, disassembly sequence planning problem is transformed into a problem of deciding the node and directed edge in the weighted blocking graph model. It can provide good base for the solution of feasible disassembly sequence. Based on the concept of disassembly hive and disassembly ring, disassembly sequence generation algorithm is put forward based on the disassembly hive and disassembly knowledge. In this algorithm, disassembly parts are abstracted disassembly hive. According to the information of disassembly model, disassembly relations of disassembly parts in the various disassembly radiuses are determined with disassembly knowledge. Then the disassembly sequence is generated with iteration and search. The disassembly sequence solution set space is expressed with the form of disassembly root diagram model. With the combination of disassembly root diagram model and heuristic algorithm, search space is provided for disassembly sequence optimum algorithm.The comparisons of basic ant colony algorithm to other improved algorithms are analyzed. A new improved algorithm is developed based on the basic ant colony algorithm, which is poisoning ant colony algorithm. Poisoning ant colony algorithm is applied to realize the search and optimization for feasible disassembly sequence solution set with disassembly root diagram. Finally, the optimal sequence is obtained based on evaluation objective function. Aim to the complexity, node transfer strategy and pheromone update rule are improved based on classical ant colony algorithm. Toxic environment and life value are also introduced to this algorithm. The characteristics of the algorithm are preferable search and convergence property. Poisoning ant colony algorithm is combined with optimal disassembly sequence search algorithm and disassembly knowledge judgment, which can reduce the computing effort and increase the practical applicability in engineering.With the growing number of parts, the complexity of mechanical products is also increased. The difficulty of disassembly sequence solution is increased. Module partition method based on multi-criteria is applied to divide complex product into some different levels and modest dimensions module, which can reduce the complexity of feasible disassembly sequence search and further improve the efficiency of disassembly planning. This method can also reduce the disassembly cost and the probability of information blasting. The probability of getting the disassembly sequence is increased.