Invited Talk 1
Harold Soh
Title: Action Hallucinations in Embodied AI
Abstract: Recent VLA models and diffusion-based robot policies are highly expressive, but robotics is not just another generative modeling problem. In this talk, I will discuss action hallucination: generated robot behaviors that violate physical feasibility or fail as executable/safe plans. For generalist robots, this is a foundational safety problem: a policy cannot be reliably safe if its action generator does not respect the structure of physical behavior. Drawing on our analysis of generative VLAs, I will argue that these failures often arise from structural mismatches between feasible robot behavior and common generative architectures, not merely from insufficient data. I will outline three barriers that help explain empirical failures in robot foundation models. I will then discuss implications for safer generalist robots, including structured action spaces and verification-guided test-time computation.
Biography
Harold Soh is an Associate Professor in the Department of Computer Science at the National University of Singapore (NUS), where he directs the Collaborative Learning and Adaptive Robots (CLeAR) group. Harold completed his Ph.D. at Imperial College London with Yiannis Demiris on online learning for assistive robots.
Harold's current research focusses on machine learning and decision-making for trustworthy collaborative robots. His work spans cognitive modeling (specifically human trust) to physical systems (perception with novel e-skins) and has been recognized with best paper award nominations at RSS, HRI, and IROS.
Harold has served on the HRI committee as LBR Co-Chair (2019) and on the Technical Advances PC as a member (2020) and chair (2021). He is an Associate Editor of the ACM Transactions on Human Robot Interaction (2021). He regularly serves as PC member or reviewer for the top publication venues in AI (NeurIPS, AAAI, IJCAI) and robotics (ICRA, IROS, RSS, HRI).