Multi-Robot Navigation in Social Mini-Games: Definitions, Taxonomy, and Algorithms

Abstract

The "Last Mile Challenge" has long been considered an important, yet unsolved, challenge for autonomous vehicles, public service robots, and delivery robots. A central issue in this challenge is the ability of robots to navigate constrained and cluttered environments that have high agency (e.g., doorways, hallways, corridor intersections), often while competing for space with other robots and humans. We refer to these environments as "Social Mini-Games" (SMGs). Traditional navigation approaches designed for MRN do not perform well in SMGs, which has led to focused research on dedicated SMG solvers. However, publications on SMG navigation research make different assumptions, and have different objective functions (safety versus liveness). These assumptions and objectives are sometimes implicitly assumed or described informally. This makes it difficult to establish appropriate baselines for comparison in research papers, as well as making it difficult for practitioners to find the papers relevant to their concrete application. Such ad-hoc representation of the field also presents a barrier to new researchers wanting to start research in this area. SMG navigation research requires its own taxonomy, definitions, and evaluation protocols to guide effective research moving forward. This survey is the first to catalog SMG solvers using a well-defined and unified taxonomy and to classify existing methods accordingly. It also discusses the essential properties of SMG solvers, defines what SMGs are and how they appear in practice, outlines how to evaluate SMG solvers, and highlights the differences between SMG solvers and general navigation systems. The survey concludes with an overview of future directions and open challenges in the field. Our project is open-sourced at https://socialminigames.github.io/{https://socialminigames.github.io/.

Figures (25)

• Figure 1: A Social Mini-Game (SMG) (taken with permission from chandra2025deadlock).
• Figure 2: General multi-robot navigation (taken with permission from fan2018crowdmove).
• Figure 4: MRN in SMGs Survey Structure
• Figure 5: Examples/Counter-examples of social mini-games: Arrows indicate the direction of motion for two agents $1$ and $2$ toward their goals marked by the corresponding cross. The first scenario is a social mini-game since both the preferred trajectories of agents $1$ and $2$ are in conflict from some $t=a$ to $t=b$ where $b-a \geq \delta$. The second and third scenarios are not social mini-games as there are no conflicts. In the second scenario, there is no duration where agents intersect one another. In the third scenario, agent $2$ has an alternate conflict-free preferred trajectory to fall back on.
• Figure 6: Velocity projection for two symmetrical SMGs with arbitrary angles $\theta$ with respect to the relative position vector. In these two examples, we examine when $\theta = \frac{\pi}{6}$ and $\theta = \frac{\pi}{3}$ (although any arbitrary $\left \lvert \theta \right\rvert < \frac{\pi}{2}$ may be chosen).

Theorems & Definitions (4)

• Definition 1
• Definition 2
• Definition 3
• Definition 4