A Genetic Algorithm for Assembly Sequence Planning

This work presents a genetic algorithm for assembly sequence planning. This problem is more difficult than other sequencing problems that have already been tackled with success using these techniques, such as the classic Traveling Salesperson Problem (TSP) or the Job Shop Scheduling Problem (JSSP). It not only involves the arranging of tasks, as in those problems, but also the selection of them from a set of alternative operations. Two families of genetic operators have been used for searching the whole solution space. The first includes operators that search for new sequences locally in a predetermined assembly plan, that of parent chromosomes. The other family of operators introduces new tasks in the solution, replacing others to maintain the validity of chromosomes, and it is intended to search for sequences in other assembly plans. Furthermore, some problem-based heuristics have been used for generating the individuals in the population

Formulation and Search of Assembly Sequence Design Spaces for Efficient Use of Assembly Plant Resources for New Products

Efficient procedures for generation of feasible assembly sequences and effective utilization of available assembly plant resources can greatly reduce the development time and cost of platforms for new product family members. This article presents a method to generate feasible assembly sequences and an approach to select an assembly process that reduces the existing plant modification cost. Assembly sequence design space is combinatorial in nature. Mathematical models to solve the effects of constraints on these spaces and algorithms to efficiently enumerate feasible spaces are explored in this research. Algorithms to search the feasible space to identify assembly process that can reduce the modification cost of the existing assembly plant can help increase utilization of existing resources. A software application that implements the method and algorithms has been developed. The algorithms use the concept of recursive partitioning of set of components to generate assembly sequence space. The assembly processes are then evaluated to determine the process that maximizes resource utilization for new platforms. The application of the proposed approach is demonstrated using automotive underbody front structure family.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

An enhanced assembly planning approach using a multi-objective genetic algorithm

10.1243/09544054JEM359Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture2202255-272PIBM

Actionneurs miniatures à alliages à mémoire de forme fabriqués par microstéréophotolithographie

A new method for the fabrication of actuators has been implemented. It is based on polymer structures built using microstereophotolithography ($\mu$SPL) integrating Shape Memory Alloy (SMA) elements. The principle of the proposed approach consists in the assembly of SMA wires together with passive mechanical architectures fabricated using $\mu$SPL techniques. A light aided assembly method based on photopolymerization has been adjusted to clamp SMA parts to $\mu$SPL parts. This approach has been implemented to build actuators using distributed elasticity or liable hinge architectures. These actuators have been associated in parallel or serie to produce new active mechanical components. Some of these actuators have been experimentally tested. The obtained results are presented and discussed.La mise au point d'un procédé de fabrication d'actionneurs associant la microstéréophotolithographie ($\mu$SPL) avec des éléments d'Alliages à Mémoire de Forme (AMF) est décrite dans le présent article. L'idée repose sur l'assemblage de fils d'AMF avec des architectures mécaniques passives en polymère réalisées par $\mu$SPL. Une étape de collage assisté par la lumière (photopolymérisation) permet de lier rigidement les fils d'AMF à la structure polymère. Cette approche a été utilisée pour fabriquer des actionneurs à élasticité répartie ou à charnières déformables. L'association de tels actionneurs en série ou en parallèle donne alors lieu à de nouveaux composants (éléments articulés), dont le principe est présenté. Certains de ces actionneurs ont été testés expérimentalement. Les résultats de ces tests sont reportés et analysés