Mar 2022 - present
NASA JPL
- semantics-aware mapping & search for signal sources in challenging environments
- mission autonomy for legged ground robot operations in multi-level unknown buildings
- search and planning for active radio signal source seeking in unknown area
NeBula - Autonomous Intelligence, Surveillance, and Reconnaissance (NAISR)
Mar 2021 - Nov 2021
US Army, National Robotics Engineering Center (NREC)
- use drones and AI to help keep tabs on the enemy
- locate, identify enemies, and feed the data to an AI for a "big picture" of the battlefield
- develop and test hexacopter-based multiple sUAS for cooperative zone recon missions
Aided Threat Recognition from Mobile Cooperative and Autonomous Sensors (ATR-MCAS)
Mars/Interplanetary Swarm Design and Evaluation Framework (MISDEF)
Sep 2019 - Dec 2020
NASA JPL, OrbitLogic
- planning & data fusion of Mars rover-drones system and operator interaction
- developed Mars Robotic Asset Cooperative Control (MRACC)
- developed distributed communication-aware informative planning
Sep 2017 - May 2020
Center for Unmanned Aircraft Systems (C-UAS), NSF
- identify position of people who have wireless equipment such as smartphone
- fuse data measured from wireless equipment (e.g. RF/vision sensors)
- implemented planning/control scheme using game theory and information theory
Multiple Aircraft Sensing System (MASS)
Path Planning for Discovering/Exploiting Thermals in Autonomous Soaring of a Glider
Jun 2017 - Aug 2017
Microsoft Research
- path planning for unpowered glider to discover/exploit thermals
- set up glider motion and Markov decision process (MDP) for airspeed/heading
- applied Monte-Carlo tree search (MCTS) based algorithm as solver
- demonstrated by actual glider experiments in Hawthorne Industrial airport, NV
Scalable Cooperative Tracking of Moving RF Ground Targets
Sep 2015 - Aug 2017
Center for Unmanned Aircraft Systems (C-UAS), NSF
- sensing/tracking RF signal from targets using heterogeneous multi-agent systems
- designed distributed systems in a way of non-cooperative game
- analyzed designed utility in terms of communication network and agent movement
Task Allocation Simulation for Controlled Emergency Response (TASCER)
Sep 2015 - May 2016
The Aerospace Corporation
- developed simulation for evaluating task assignment in disaster scenarios
- implemented agent/gimbal/sensor dynamics for search and rescue missions
Decentralized Path Planning and Control of Multiple UAVs for Information-Theoretic Search and Track
May 2012 - Apr 2015
National Research Foundation, South Korea
- developed decentralized system for search and track missions of multiple UAVs
- implemented negotiation-based task assignment for search/track tasks
Optimal Kinodynamic Path Planning using RRT
Sep 2013 - Dec 2013
Agency of Defence Development, South Korea
- developed optimal trajectory generation algorithm for search missions of UGV
- applied closed loop rapidly-exploring random trees (CL-RRT) for UGV dynamics
Measurement of Dynamic Stability Derivatives for an Airborne Vehicle
May 2013 - Dec 2013
Agency of Defence Development, South Korea
- implemented motor-rig mechanical system using standard dynamic model (SDM)
- applied autocorrelation-based approach for data reduction/noise elimination
- applied forced oscillation technique to obtain dynamic stability derivatives (DSD)
- experimented in 1.5 meters wind tunnel
Distributed System for Multiple UAVs
May 2009 - Dec 2010
Agency of Defence Development, South Korea
- integral framework of task assignment/path planning/collision avoidance
- implemented negotiation-based task assignment interlocked with path planning part
- developed geometric intersection-based heuristic path planning
- applied model predictive control (MPC)-based replanning for unknown threats
- demonstrated by Xplane/Simulink-based simulation and real flight tests
Development of an Autonomous Ground Vehicle
Oct 2009 - Nov 2010
Hyundai-KIA Motors, South Korea
- implemented autonomous vehicle by remodeling from Soul (commercial vehicle)
- developed algorithm for obstacle detection/avoidance using laser scanners
- applied model predictive control (MPC) using bicycle dynamics model
Development of Unmanned Helicopters for Agricultural Applications
Mar 2009 - Jun 2010
Korean Ministry of Commerce, Industry, and energy, South Korea
Wonseen Skytech, South Korea
- developed unmanned agricultural helicopters which payload is over 30 kg
- implemented two crop-dusting algorithms for complex-shaped farms
- developed obstacle/corner-based field split and Boustrophedon-based planning
- developed optimal waypoint selection from sprayed waypoint candidates
Development of a GPS-based Autonomous Parafoil Control System
Jun 2007 - Nov 2007
Korea Aerospace Industries Association, South Korea
- developed autonomous parafoil landing system to deliver 2kg-payload to ground
- designed gondola with parafoil released from mothership
- used U-Blox standard GPS receiver (5-10 meters accuracy)
- demonstrated with Maxi Joker 3 unmanned helicopter as mothership
Embodiment of Wing Model for Flapping Ornithopter imitated Shoulder Enarthrosis and Carpal of Birds
Nov 2006 - Jun 2007
KAIST, South Korea
- developed ornithopter for imitating 1.5m winspan/1kg weight goshawk
- implemented flapping mechanism by controlling angle of attack and primary feathers
- implemented soaring/gliding modes
