Decay-Based Error Correction in Collective Robotic Construction

Abstract

Multi-robot systems have been shown to build large-scale, user-specified structures using distributed, environmentally-mediated coordination in simulation. Little attention, however, has been devoted to error propagation and mitigation. In this paper, we introduce a detailed simulation of TERMES, a prototypical construction system, in which robots have realistic error profiles. We use this simulator and 32 randomly generated 250-brick blueprints to show that action errors can have significant long-term effects. We study the spatio-temporal error distribution and introduce and characterize the efficacy of a simple decay-based error correction mechanism. Although inefficient, this type of error correction is promising because it can be performed by robots with the same limited sensory capabilities as those who place bricks. To limit the impact on the construction rate, we also examine decay mechanisms informed by spatial and temporal error distributions. The incorporation of decay in our building process increases the probability of successful completion by ~ 4, at the expense of ~1/4 decrease in construction rate.