Sophie (Ya-Chuan) Hsu

I'm a 5th-year PhD candidate at USC, advised by Professor Stefanos Nikolaidis. My research lies at the intersection of reinforcement learning (RL) and human-robot interaction (HRI).

I am interested in enabling robots to effectively collaborate with humans by inferring human's intentions and reactions in uncertain and dynamic environments. At ICAROS lab, I study diverse collaboration behaviors, develop hierarchical POMDP frameworks for human-aware robotic planning under uncertainty, and infer human observation functions to improve robot decision-making in tasks. I have interned at Toyota Research Institute working with Guy Rosman, Jonathan DeCastro and Andrew Silva on designing an assistive driving system.

Prior to joining USC, I completed my M.S. in Computer Science and Engineering at Texas A&M University, advised by Professor Dylan A. Shell. where I worked on pedestrian-aware autonomous vehicle planning. I also work with Professor Swaminathan Gopalswam and Professor Srikanth Saripall at the Texas A&M Transportation Institute, formalizing human-machine communication protocols and deploying a behavior planner using ROS on a Ford Lincoln MKZ platform.

Feel free to say hi: yachuanh at usc dot edu

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Research

Integrating Field of View in Human-Aware Collaborative Planning
Ya-Chuan Hsu, Michael Defranco, Rutvik Patel, Stefanos Nikolaidis
ICRA, 2025
Paper | Code

This paper integrates human field-of-view (FOV) limitations into robot planning by adapting to the evolving subtask intent of humans based on their limited perception. To manage the resulting computational complexity, we propose a hierarchical online planner. In a steakhouse domain study, our FOV-aware planner reduced human interruptions and redundant actions. We further demonstrate our planner in a virtual reality kitchen environment.

Surrogate Assisted Generation of Human-Robot Interaction Scenarios
Varun Bhatt, Heramb Nemlekar, Matthew C. Fontaine, Bryon Tjanaka, Hejia Zhang, Ya-Chuan Hsu, Stefanos Nikolaidis
CoRL, 2023
arXiv

We propose using surrogate models to efficiently generate diverse and reproducible failure scenarios in human-robot interaction tasks, reducing the computational cost of traditional simulation-based methods.

Generating diverse indoor furniture arrangements
Ya-Chuan Hsu, Matthew C. Fontaine, Sam Earle, Maria Edwards, Julian Togelius, Stefanos Nikolaidis
SIGGRAPH Poster, 2022
arXiv

We propose a method using GANs and a quality diversity algorithm to generate realistic and diverse indoor furniture arrangements, varying in attributes like price and number of pieces.

On the Importance of Environments in Human-Robot Coordination
Matthew C. Fontaine*, Ya-Chuan Hsu*, Yulun Zhang*, Bryon Tjanaka, Stefanos Nikolaidis
RSS, 2021
Project Page / arXiv

Research on human-robot collaboration often focuses on robot policies for fluent teamwork, overlooking the impact of the environment on coordination. We propose a framework for procedurally generating environments that are stylistically human-like, solvable by human-robot teams, and diverse in coordination behaviors.

A POMDP Treatment of Vehicle-Pedestrian Interaction: Implicit Coordination via Uncertainty-Aware Planning
Ya-Chuan Hsu, Swaminathan Gopalswamy, Srikanth Saripalli, Dylan A Shell
IROS, 2020
Paper

This paper tackles the challenge of resolving ambiguous traffic situations where autonomous vehicles cannot directly communicate intent. It proposes a model using a partially observable Markov decision process (POMDP) to produce changes in speed to express intent. The approach is validated in a simulated vehicle-pedestrian crossing and tested in real-world trials with a self-driving car, demonstrating safe and efficient navigation.

An MDP model of vehicle-pedestrian interaction at an unsignalized intersection
Ya-Chuan Hsu, Swaminathan Gopalswamy, Srikanth Saripalli, Dylan A Shell
VTC-Fall, 2018
Paper

This paper is a preliminary study on communication between pedestrians and autonomous vehicles at unsignalized intersections. We propose a decision-theoretic model, using an MDP framework inspired by psychological studies, to represent pedestrian-vehicle interactions.

Service

  • Serving as a PhD mentor for the Women in Engineering (WiE) at USC.
  • Serving/Served as a reviewer for ICRA 2025, HRI 2025, THRI 2024, THRI 2023, HRI 2022 (LBR), THRI 2021, HRI 2021, RSS 2021
  • Teaching

  • CSCI 545: Introduction to Robotics (Master's Level)   -   Fall 2021, 2023, 2024
  • CSCI 641/699: Computational Human-Robot interaction (PhD Level)   -   Spring 2023, 2024
  • CSCI 170: Discrete Methods in Computer Science (Undergrad Level)   -   Spring 2021

  • Inspired by this and this.