Princeton Robotics - Ensuring Robot Safety Through Safety Index Synthesis

Safety Index is a special class of high order control barrier functions. Its purpose is to ensure forward invariance within a user-specified safe set and achieve finite time convergence to that set. Synthesizing a valid safety index poses significant challenges, particularly when dealing with control limits, uncertainties, and time-varying dynamics. In this talk, I will introduce a variety of approaches that can be used for safety index synthesis, including a rule-based method, an evolutionary optimization-based approach, a constrained reinforcement learning-based approach, an adversarial optimization-based approach, as well as sum of square programming. The parameterization of the safety index can either take an analytical form or be a neural network. I will conclude the talk by highlighting the limitations of existing work and discuss potential future directions, including integrating formal verification into neural safety index synthesis.

Bio: Dr. Changliu Liu is an assistant professor in the Robotics Institute, School of Computer Science, Carnegie Mellon University (CMU), where she leads the Intelligent Control Lab. Prior to joining CMU, Dr. Liu was a postdoc at Stanford Intelligent Systems Laboratory. She received her Ph.D. in Engineering together with Master degrees in Engineering and Mathematics from University of California at Berkeley and her bachelor degrees in Engineering and Economics from Tsinghua University. Her research interests lie in the design and verification of intelligent systems with applications to manufacturing and transportation. She published the book “Designing robot behavior in human-robot interactions” with CRC Press in 2019. She is the founder of the International Neural Network Verification Competition launched in 2020. Her work has been recognized by NSF Career Award, Amazon Research Award, Ford URP Award, Advanced Robotics for Manufacturing Champion Award, and many best/outstanding paper awards.

Students: Sign-up for lunch with the speaker here (12:00 - 1:30 PM.)