Onboard Geomagnetic Field Generation Module for CubeSat Attitude Control Simulations

In recent decades, employing small satellites in low earth orbit (LEO) has an increasing tendency. Generally, they are equipped with a magnetic torque actuator (e.g., magnetorquer, MTQ) and a reaction wheel (RW) that are associatively manipulated to perform various operation modes. As a matter of fact, the LEO satellites functionally experience the Earth’s magnetic field more than other spacecrafts, and the B-dot control scheme inherently utilizing the geomagnetic field is unanimously applied among small satellites mainly for the maneuvers of attitude detumbling and RW momentum desaturation. In this paper, perceiving the need for a geomagnetic field generation module to provide a LEO environment when developing CubeSat’s ADCS, an integrated “Onboard Geomagnetic Field Generation Module (OGFGM)” consisting of an orbit propagator, an IGRF model, and coordinate rotation matrices is proposed, which can be flexibly and conveniently embedded in the relevant systematical platforms (e.g., model-in-the-loop (MIL), hardware-in-the-loop (HIL), etc.) to render the in-orbit geomagnetic conditions, enabling the dynamic magnetic field simulations required for ADCS research and design (R&D) as well as relevant experimental testing to be performed in a real-time and coherent manner. In this work, the computed local geomagnetic fields (BNED) of three orbit types (e.g., ISS, Polar, and Equatorial) are validated with the BGS (British Geological Survey) website IGRF calculator, the integrity of respective geomagnetic field conversions during the MIL simulation is examined, and performance of the B-cross control scheme adopting mechatronics engineering strategy is simulated in the MATLAB/Simulink environment showing a substantial enhancement in actuation effort.