Formal Synthesis of Safety Controllers for Unknown Stochastic Control Systems

April 8, 2022 1:00 PM – 2:00 PM via Zoom

Speaker: Rameez Wajid, Computer Science Department, University of Colorado, Boulder.


Formal synthesis of controllers for stochastic control systems with unknown models is a challenging problem. We focus on safety controller synthesis for nonlinear stochastic control systems. The approach consists of a learning step followed by a controller synthesis scheme using control barrier functions. In the learning phase, we employ Gaussian processes (GP) to learn models of unknown stochastic control systems in the presence of both process and measurement noises. In the controller synthesis phase, we compute control barrier functions together with their corresponding controllers based on the learned GP and quantify lower bounds on the probabilities of safety satisfaction for the original unknown systems equipped with the synthesized controllers. Finally, the effectiveness of the proposed approach is illustrated on a room temperature control and a vehicle lane-keeping example.


Rameez Wajid is a PhD student in the Computer Science Department at the University of Colorado Boulder. He is an Avionics Engineer by training and also has an MS degree in Control Systems. He has worked in both the industry and academia. During his industry stint, he helped develop low-cost Flight Simulation and In-flight Situational Awareness Systems. He also taught undergraduate avionics engineering classes for over three years at the National University of Sciences and Technology (NUST). His current research interests lie at the intersection of Control theory, Formal methods and machine learning.