M.S. Candidate · Aerospace Engineering · Seoul National University

I design GNC architectures where a proven inner-loop keeps its safety guarantees intact, and a null-space (or otherwise non-disruptive) channel adds performance that the primary loop cannot see. Learning is used as augmentation — never as a replacement for the stability margins engineers already have.

Focus · control allocation · null-space methods · SCP / MPC / QP · reinforcement-learning augmentation · space robotics · reusable launch vehicles · embedded flight software

A load-decoupled downrange-drag channel for reusable launch vehicles, living in the null space of the grid-fin moment-allocation matrix. The attitude loop keeps tracking exactly as before; drag modulation is added on top without leaking torque into the primary loop.

_{control-allocation · null-space · grid-fins · 6dof-simulation · reusable-launch-vehicle}

🎥 Video demo — TD3-adaptive MPC vs fixed-weight baseline

Falcon 9 6-DOF powered-descent guidance with a three-layer GNC: SCP (trajectory optimization) + MPC (tracking, always the safety layer) + TD3 (adapts MPC weights inside the safe envelope — never overrides the constraint set). 99.4 % success over N=500 Monte Carlo with wind. Ships with a MATLAB → Python (CVXPY) → C (CVXPYgen) → Raspberry Pi HILS porting track.

_{scp · mpc · td3 · hardware-in-the-loop · cvxpygen · raspberry-pi · falcon9}

🎥 Video demo — dock-and-return under payload inertia change

A TD3 agent that learns the 1-D null-space parameter α(t) of a 7-DOF free-floating space manipulator. End-effector tracking is exactly preserved by the QP/IK layer; the learned α reduces base recoil under payload-induced inertia changes, a regime where fixed rules (energy-optimal or recoil-optimal) both degrade.

_{space-robotics · null-space · td3 · free-floating-base · matlab}

The 2D precursor to NS-TD3. Same null-space TD3 idea validated on 3- and 4-link planar free-floating manipulators, where the 1-D null-space direction is directly visualizable in joint-velocity space — making the α-A / α-B / α-RL trade-off explicit before scaling to 3D.

_{null-space · td3 · simulink · planar-robot · free-floating-base}

ESP32-S3 + SimpleFOC BLDC reaction wheel for a Floating Spacecraft Simulator (FSS). Full stack from theory to flight release: linear analysis → Simulink dynamics → 31-stage systematic firmware bring-up (boot → I²C → open-loop → FOC → torque tracking → high-speed) → packaged flight controller with a documented USB-CDC protocol.

_{bldc · foc · esp32-s3 · simplefoc · embedded · reaction-wheel · cubesat}

✉️ junesuk61212@gmail.com  ·  🎓 Seoul National University, Aerospace Engineering