Research On Electromechanical Product Disassembly Sequence Planning Based On Partial Destruction Mode

At present, China's manufacturing industry is facing the dual pressures from the waste of resources and environmental pollution. The key to solve these problems is to take a sustainable development path in line with manufacturing. Manufacturing of sustainable development requires us not only to take both of waste of resources and environmental pollution into account in early product life cycle, but also requires us to find an effective way to solve a large number of electromechanical products which have been or will be scrapped. Therefore, disassembly recycling is a great and unique way to deal with thousands of products. The existing disassembly way which is blindness disassembly in a small workshop is not good; however, such way is inefficient and may cause environmental pollution and even a potential threat to the health of workers especially for complex electromechanical products. Computer-aided product disassembly sequence planning method can better solve this problem. Disassembly sequence planning is a way which can generate the path to guide the process of disassembly based on the products' internal structure and assembly constraint relationship and other information. Disassembly can be divided into three types:complete destruction disassembly, partial destruction disassembly and non-destruction disassembly. Existing disassembly sequence planning methods are based on the non-destruction disassembly method, which can not be reasonably resolved in the problems of Non-Disassembly of Theory (NDT) and Non-Disassembly of Process (NDP). These problems may reduce the disassembly efficiency and increase the cost of disassembly.In order to solve the problem of NDT, this paper presents a method of electromechanical product disassembly sequence planning based on partial destruction mode NDT problems. A method of parts disassembly direction has been proposed to search for a point which can not be disassembled theoretically. This paper also presents the objectives inverse method (OIM) to obtain the physical shortest disassembly path. Then the disassembly cost criteria are constructed under the two models, and finally generate the optimized disassembly sequence by the comparison between two disassembly sequences. The results show that the method improves the disassembly efficiency and reduces the cost of disassembly.In order to solve the problem of NDP, this paper presents the electromechanical product disassembly sequence planning method based on partial destruction mode NDP problems. It proposes a method of model rebuilt which constructs the disassembled parts (DP) and the set of affected parts (SAP) and the sub-set of affected parts (SSAP) to update the mode. And then generate the disassembly method and sequence by the proposed optimization algorithm. The results show that the method can solve the NDP problem and reduce the cost of disassembly.This paper makes a disassembly sequence planning simulation system by the software Matlab and SQL Server to verify the above method. The system is divided into three modules:the disassembly information modeling initialization, the disassembly sequence planning module under NDT and the disassembly sequence planning module under NDP. The effect of the disassembly information modeling initialization is to construct the information basement for product disassembly by inputting the information into SQL database. The disassembly sequence planning modules of NDT and NDP can solve two different disassembly problem, respectively. The relationship between the two modules is not only linked but also independent.Finally, taking the drum washing machine for example to prove the correctness and effectiveness of the methods described above, which can avoid both the "rotary draw bending" phenomenon and NDP problems. The example also verifies the utility of the simulation system.