Robots that Learn to Safely Influence via Prediction-Informed Reach-Avoid Dynamic Games

TL;DR

This paper introduces SLIDE, a novel game-theoretic approach enabling robots to influence humans safely by reasoning about human behavior and uncertainty, improving efficiency without compromising safety.

Contribution

The work presents a new robust reach-avoid dynamic game framework that incorporates influence and safety, solved via offline reinforcement learning in high-dimensional spaces.

Findings

SLIDE enables influence when safe, reducing conservativeness.

Compared to baselines, SLIDE maintains high safety while increasing influence.

The method is demonstrated in a 39-D simulated manipulation task.

Abstract

Robots can influence people to accomplish their tasks more efficiently: autonomous cars can inch forward at an intersection to pass through, and tabletop manipulators can go for an object on the table first. However, a robot's ability to influence can also compromise the safety of nearby people if naively executed. In this work, we pose and solve a novel robust reach-avoid dynamic game which enables robots to be maximally influential, but only when a safety backup control exists. On the human side, we model the human's behavior as goal-driven but conditioned on the robot's plan, enabling us to capture influence. On the robot side, we solve the dynamic game in the joint physical and belief space, enabling the robot to reason about how its uncertainty in human behavior will evolve over time. We instantiate our method, called SLIDE (Safely Leveraging Influence in Dynamic Environments), in a high-dimensional (39-D) simulated human-robot collaborative manipulation task solved via offline game-theoretic reinforcement learning. We compare our approach to a robust baseline that treats the human as a worst-case adversary, a safety controller that does not explicitly reason about influence, and an energy-function-based safety shield. We find that SLIDE consistently enables the robot to leverage the influence it has on the human when it is safe to do so, ultimately allowing the robot to be less conservative while still ensuring a high safety rate during task execution.