Author ORCID Identifier

https://orcid.org/0009-0003-2344-1351

Date Available

12-16-2025

Year of Publication

2025

Document Type

Master's Thesis

Degree Name

Master of Science in Mechanical Engineering (MSME)

College

Engineering

Department/School/Program

Mechanical Engineering

Faculty

Hasan Poonawala

Faculty

Jonathan Wenk

Abstract

Small satellites must execute precise, fuel-limited maneuvers under strict actuation and operational constraints. Model Predictive Control (MPC) is a suitable approach because it optimizes future actions while explicitly enforcing these limits. This work evaluates (1) whether MPC can operate in real time using binary (on/off), asymmetric thrusters, and (2) whether a high-fidelity digital twin can be used to tune and validate the controller prior to hardware testing.

An MPC framework was implemented on a planar satellite prototype that floats on air bearings, operates at 16.7 Hz (60 ms period), and uses eight binary thrusters exhibiting up to 13.2% variation in measured force. A mixed-integer MPC formulation generated optimal on/off thruster sequences to minimize tracking error and propellant use. A corresponding digital twin was developed using matched physical parameters, and the same controller executed an identical mission in simulation and hardware.

Results showed close agreement between the two environments. The system achieved a mean position tracking error of 0.179 m, a final position error of 0.024 m, and a final attitude error of 0.51°. Total thruster-on time differed by only 1.5% over a 200 s trajectory. The solver satisfied the 50 ms real-time deadline in all cycles, with an average solve time of 4.61 ms and a worst-case time of 32.10ms.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2025.583

Funding Information

This thesis was partially supported by grant "NASA KY EPSCOR RIDG-24-003: In-Space Servicing And Assembly With Electromagnetic Small Satellites" and the Department of Mechanical & Aerospace Engineering.

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