Algorithmic Approaches to Reconfigurable Assembly Systems

Abstract

Assembly of large scale structural systems in space is understood as critical to serving applications that cannot be deployed from a single launch. Recent literature proposes the use of discrete modular structures for in-space assembly and relatively small scale robotics that are able to modify and traverse the structure. This paper addresses the algorithmic problems in scaling reconfigurable space structures built through robotic construction, where reconfiguration is defined as the problem of transforming an initial structure into a different goal configuration. We analyze different algorithmic paradigms and present corresponding abstractions and graph formulations, examining specialized algorithms that consider discretized space and time steps. We then discuss fundamental design trades for different computational architectures, such as centralized versus distributed, and present two representative algorithms as concrete examples for comparison. We analyze how those algorithms achieve different objective functions and goals, such as minimization of total distance traveled, maximization of faulttolerance, or minimization of total time spent in assembly. This is meant to offer an impression of algorithmic constraints on scalability of corresponding structural and robotic design. From this study, a set of recommendations is developed on where and when to use each paradigm, as well as implications for physical robotic and structural system design.

Industry 4.0 and Prospects of Circular Economy: A Survey of Robotic Assembly and Disassembly

“…Moreover, if applicable, the cost associated with hazardous tasks could be considered as an extra objective [12]. In contexts such as the assembly of re-configurable structures, other common optimization criteria include fault tolerance and the total distance travelled [54]. Other factors involved in typical DLBPs include the consistency in the amount of idle time that different workstations experience, as well as fast or prior manual removal of highly demanded or dangerous parts.…”

“…Its benefits arise from the capability of assembling modular structures, which make it possible to traverse and revise the configuration. In fact, in the foregoing context, the problem is defined as that of transforming a structure from the original configuration to a goal one [54]. The scope and practicability of outer-space missions could be greatly enhanced through utilizing on-orbit robotics and assembly, whereby, outer-space exploration hardware could be reused for a lower cost.…”

Material–Robot System for Assembly of Discrete Cellular Structures

“…Algorithmically, we see tradeoffs between centralized and distributed systems. This was studied by Costa et al [30], and results indicate that systems with large numbers of robots and parts benefit from a distributed control architecture, while a centralized approach can provide near-optimal solutions for smaller systems. The latter will be employed in this work.…”

“…We employ a centralized control system, whereby a single platform (in this case, a laptop), computes and schedules single and multi-robot coordination. While this is well understood to be susceptible to a single point of failure, it allows for near-optimal path computation, and reduces robot sensing and computing requirements [30]. Development of a distributed approach is addressed in the Discussion section.…”

Research of the Influence of Production Technologies on the Positioning Accuracy of a Robotic Arm for Low Handling Weights

“…Mick et al [9] proposed a prototype of a robotic arm made using 3D printing, which is also economically more advantageous compared to the price of an industrial robot thanks to conventional drives. Junia Santillo Costa et al [10] implemented and validated a 3D printed Open Source robotic arm with 6 degrees of freedom made of ABS material, due to higher mechanical strength. Ismail et al [11] designed and developed a robotic arm for lifting light parts with 4 degrees of freedom.…”