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The research in the FD&C/HS Lab (Lab Director: Professor Inseok Hwang) focuses on two directions:

  • fundamental research on the Cyber-Physical System (CPS), which is a complex (networked) system with interacting physical and logical components, using hybrid systems theory; and
  • its applications to safety-critical aerospace systems such as:
    • Intelligent systems: aircraft, spacecraft, and unmanned aircraft systems (UAS); and
    • Networked systems: transportation systems, sensor networks, and multiple-vehicle systems (e.g., swarm of UAS)

Note that aerospace systems are good examples of the CPS. For example, a UAS (similarly, aircraft and spacecraft) is composed of anautopilot which is a logical element and a vehicle that is a physical element, thus it is a CPS.

Hybrid Systems Theory

In theory, our group studies modeling, analysis and control of the stochastic hybrid system (SHS) which is a dynamical system with the interacting discrete dynamics (represents the logical/cyber behavior) and continuous dynamics (describes the physical behavior) of the CPS with uncertainties, and thus it can accurately model the CPS.

Our group develops a set of SHS models and corresponding hybrid estimation and control theory and algorithms which can deal with a range of SHS computationally efficiently, and thus can be applied to various complex CPS applications.

  • Hybrid Systems Modeling
  • Hybrid Estimation
  • Optimal Control of Hybrid Systems

We further extend our hybrid systems research to a wide range of problems such as

  • Event-based state estimation for SHS (e.g., sensor/vehicle network);
  • Optimal state estimation and control for partially observable SHS (e.g., UAS control algorithm);
  • Robust state estimation for SHS; and
  • Fault detection and identification for state constrained SHS (e.g., cybersecurity of UAS).


In applications, our research interests include ATC, UAS and space applications.

Air Traffic Control (ATC)

For ATC, we develop a set of automation algorithms and supporting tools such as

  • Safe separation assurance;
  • Aircraft tracking and 4D trajectory prediction;
  • Airspace/airport conformance monitoring and safety verification;
  • Modeling the national airspace system (NAS) with uncertainty; and
  • Dynamic airspace reconfiguration.

Recently our ATC research focuses on aviation safety and security. The algorithms and methodologies developed for aviation safety and security include

  • Formal verification and validation (V&V) for flight deck;
  • Human-machine interaction (HMI) issue (e.g., pilot’s w=rong interaction with autopilot in the cockpit) detection; and
  • Big data analytics for large-scale flight data analysis using data mining and machine learning techniques.


Image from NASA

Unmanned Aircraft Systems (UAS)

As for UAS, we focus on guidance, navigation and control (GNC) and cybersecurity and high assurance control of the UAS, which has become crucial for safe and secure operation of UAS in various civilian and military applications.

Guidance, Navigation, and Control (GNC)

  • localization and mapping
  • sensor fusion
  • UAS modeling and control

Cyber Security and High Assurance Control of the UAS

  • cyber-attack vulnerability analysis which can identify vulnerabilities of the UAS and assess its degree of severity by characterizing the compromised behavior of the UAS
  • development of cyber security monitoring systems and high assurance control design which can allow for the UAS whose physical operations are resilient to the damage caused by cyber-attacks, successfully complementing the existing computer-security-based UAS cybersecurity technology.

For algorithm development and validations, we develop

  • open-source based autonomous unmanned vehicle system platforms; and
  • software/hardware-in-the-loop testbeds.

Space Applications

Furthermore, our research interests include space applications and we develop theory and algorithms for

  • optimal control of low-thrust orbit transfer;
  • satellite formation/attitude control; and
  • maneuver detection and tracking algorithms for spacecraft for space situational awareness.

Image from NASA

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