Abstract:PurposeIn this paper, an assembly sequence planning system, based on binary vector representations, is developed. The neural network approach has been employed for analyzing optimum assembly sequence for assembly systems.Design/methodology/approachThe input to the assembly system is the assembly's connection graph that represents parts and relations between these parts. The output to the system is the optimum assembly sequence. In the constitution of assembly's connection graph, a different approach employing … Show more
“…There are other algorithms based on different techniques: ant colonies [21,19,6], neural networks [17], evolutionary algorithms [5,13] and Immune Optimization Approaches(IOA) [3]. Alternatively to perform a graph search, reference [14] proposes to transform the liaisons graph into a table of liaisons in matrix form where a feasible sequence can be found by successively deleting the columns of the parts already included in the assembly and examining their rows for other candidate liaisons to be established.…”
Section: Methods To Compute the Assembly Sequencesmentioning
Abstract. This paper deals with the automatic computation of the assembly sequence for building truss structures from their 3D geometrical analysis. This functionality is part of the autonomous planning architecture of a team of aerial robots equipped with on-board robotic arms. The mission of the team is the construction of a structure in places where the access is difficult by conventional means. The assembly sequence is computed by applying the well known "assembly-by-disassembly" technique to the Non-Directional Blocking Graphs (NDBG) obtained from the geometrical analysis of the structure. In this paper two novel local heuristics are presented to solve the assembly problem: the former is based on the number of free nodes in the graphs and the latter is related to the size of the resulting connected subgraphs when each disconnection is applied to a set of parts. Both techniques are designed to compute the assembly sequence that allows to parallelize the building process of the structure if enough robots are available. Simulation results as well as experimental results with an aerial robot are presented in the paper.
“…There are other algorithms based on different techniques: ant colonies [21,19,6], neural networks [17], evolutionary algorithms [5,13] and Immune Optimization Approaches(IOA) [3]. Alternatively to perform a graph search, reference [14] proposes to transform the liaisons graph into a table of liaisons in matrix form where a feasible sequence can be found by successively deleting the columns of the parts already included in the assembly and examining their rows for other candidate liaisons to be established.…”
Section: Methods To Compute the Assembly Sequencesmentioning
Abstract. This paper deals with the automatic computation of the assembly sequence for building truss structures from their 3D geometrical analysis. This functionality is part of the autonomous planning architecture of a team of aerial robots equipped with on-board robotic arms. The mission of the team is the construction of a structure in places where the access is difficult by conventional means. The assembly sequence is computed by applying the well known "assembly-by-disassembly" technique to the Non-Directional Blocking Graphs (NDBG) obtained from the geometrical analysis of the structure. In this paper two novel local heuristics are presented to solve the assembly problem: the former is based on the number of free nodes in the graphs and the latter is related to the size of the resulting connected subgraphs when each disconnection is applied to a set of parts. Both techniques are designed to compute the assembly sequence that allows to parallelize the building process of the structure if enough robots are available. Simulation results as well as experimental results with an aerial robot are presented in the paper.
“…Through recognizing sub-assemblies of different sizes in a complex assembly, a hierarchical assembling structure of the assembly can be formed. Thus, the complex assembly sequence planning problem is decomposed into several sub-problems, reducing assembly difficulty, facilitating the generation of assembly sequences, and improving assembly planning efficiency [1] . That can better guide product assembling process and reduce assembly costs.…”
Abstract. In order to simplify assembly sequences, reduce assembly difficulty and costs, and guide product assembling process, a sub-assembly identification algorithm is presented and applied to assembly sequence planning problems in the field of intelligent planning. It is used to identify sub-assemblies in the assemblies of different sizes. Through establishing a weighted undirected connected graph, the relations between the parts in an assembly is represented and base parts are determined. The algorithm is designed and realized in Matlab. Its feasibility is verified by a motorcycle assembly instance. It is proved that the sub-assembly identification algorithm can be used to optimize assembly sequences and shorten assembly sequence planning time.
“…As usual in NN, energy functions can be defined related to the input and output values of the neurons, and in the present case they are formulated so as to correspond to an optimal assembly sequence when a global optimum of these functions is reached. Other more recent works using back-propagation neural networks for assembly sequence optimization are Cem Sinanoglu (2005) and Chen et al (2008).…”
Section: Advanced Sequencing and Optimization Techniquesmentioning
confidence: 99%
“…There are academic toy assemblies (a 5-part 2D assembly in Jiménez and Torras (2000) and Ben-Arieh et al (2004), or a 20-part hypothetical product in Motavalli and Islam (1997)), but the majority prefer to show experiments on real assemblies. These range from a 4-part pince in Cem Sinanoglu (2005) to the 48-part gear-box in Chen and Liu (2001). Grouped by type of algorithm (the number of parts shown in parentheses), these examples include:…”
Section: Case Studies In the Literaturementioning
confidence: 99%
“…Petri nets a flashlight (4) Caselli and Zanichelli (1995) and a ball-point pen (5) Suzuki et al (1993); 2. simulated annealing a relay (10) Hong and Cho (1999); 3. neural networks a pince (4), a hinge (4) and a coupling system (7) Cem Sinanoglu (2005), a gearbox (10) Chen (1992), a relay (10) and an alternator (13) Hong and Cho (1995), and an electric torch (16) Chen et al (2008); 4. genetic algorithms an oil pump (5) Bonneville et al (1995), an industrial controller (19) Guan et al (2002), an hydraulic linear motor (25) Marian et al (2006), an air condition control (28) Sebaaly et al (1996), a signaling relay ( This list -which by no means pretends to be exhaustive-should be interpreted as an illustration of the variety of assemblies dealt with in the existing literature, not as a ranking of the suitability of the different sequencing and optimization algorithms. Furthermore, the examples provided by the authors are generally more oriented towards explaining how their algorithms work than to demonstrate their performance.…”
A systematic overview on the subject of assembly sequencing is presented. Sequencing lies at the core of assembly planning, and variants include finding a feasible sequence -respecting the precedence constraints between the assembly operations-, or determining an optimal one according to one or several operational criteria. The different ways of representing the space of feasible assembly sequences are described, as well as the search and optimization algorithms that can be used. Geometry plays a fundamental role in devising the precedence constraints between assembly operations, and this is the subject of the second part of the survey, which treats also motion in contact in the context of the actual performance of assembly operations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.