WPI Plans for Fall Opening Latest Information

ECE MS Thesis Presentation by Hongchao Zhang, via Zoom

Wednesday, July 22, 2020
2:00 pm to 4:00 pm
Floor/Room #: 
via Zoom meeting link


Control Barrier Functions for Safe Cyber-Physical Systems Under Sensor Faults and Attacks



CPS safety, defined as the system state remaining within a desired safe region, is a critical property in applications including medicine, transportation, and energy. Sensor faults and attacks may cause safety violations by introducing bias into the system state estimation, which in turn leads to erroneous control inputs. In this paper, we propose a class of Fault-Tolerant Control Barrier Functions (FT-CBFs) that provide provable guarantees on safety of stochastic CPS. Our approach is to maintain a set of state estimators, each of which ignores a subset of sensor measure- ments that are affected by a particular fault pattern. We then introduce a linear constraint for each state estimator that ensures that the estimated state remains outside the unsafe region, and propose an approach to resolving conflicts between the constraints that may arise due to faults. We present sufficient conditions on the geometry of the safe region and the noise characteristics to provide a desired probability of maintaining safety. We then propose a framework for joint safety and stability by integrating FT-CBFs with Control Lyapunov Functions. Our approach is validated through both numerical study and hardware implementation of an obstacle avoidance case study using a Turtlebot wheeled robot.


Research Advisor:

Professor Andrew Clark

ECE Department, WPI


Research Committee:

Professor Ziming Zhang

ECE Department, WPI

Professor Jie Fu

ECE Department, WPI


Zoom Meeting Link:

Please contact Hongchao Zhang directly at hzhang9@wpi.edu for the link to his presentation.