Research On Disassembly Sequence Planning Based On Genetic Algorithms

Disassembly sequence planning as one of the most important aspect of green design and product disassembly recycling is being more and more concerned. Currently, research on disassembly has become a hot issue. Disassembly sequence planning is an important component of product disassembly research. Disassembly sequence planning which is under the condition of product disassembability, for certain goals is to determine the disassembly sequence of products from the assembly.There are three key issues in disassembly sequence planning:â‘ modeling of demolition product information;â‘¡strategies of computing disassembly sequences.â‘¢evaluation and optimization of disassembly sequences. Based on the current researches in these issues, this thesis proposes a series of method to generate, evaluate and optimize product disassembly sequences in large scale. Contributions of this thesis are as following:â‘ product disassembly information model is the basis of the study and is one of the main contents of disassembly sequence planning. In this thesis, a detailed analysis of assembly modeling research status is brought forward firstly, then suggests an enhanced connectivity graph and its connectivity matrix to express product information and the interrelationship between the parties of the disassembly. The concept of subassembly is introduced, then the information of disassembly model is simplified, also the model redundant information is reduced.â‘¡The main disassembly sequence generation method is presented, the disassembly precedence constraint relations between the components are analyzed. Then the thesis establishes the disassembly precedence relation matrix. Based on guided search strategy, under the guidance of disassembly precedence relations, feasible disassembly sequence are generated, which formulate the practicable disassembly sequence initial population.â‘¢Genetic algorithms principle and methodology are presented,considering the characteristic of disassembly sequence planning, proper coding manner,genetic operator and fitness function are given. Evaluation and optimization for disassembly sequencing are completed by fitness function, so feasible sequences are obtained. The validity of GAs on disassembly sequence planning are convinced.