Closed-Loop Simulation of CubeSats

Technical Project - IIT Bombay Student Satellite Program

Designation: Controls Engineer
Duration: January 2019 - January 2020

Satellites require attitude (orientation) control for a variety of reasons: for the payload, to maintain a charged-up battery, and so on. Attitude control (and estimation) algorithms programmed into the satellite's on-board computer need to be extremely reliable, since failure can prove fatal to the mission. It is therefore of paramount importance that they are tested and validated rigorously before deployment.

Testing them using actual hardware is often very complicated and expensive, which leaves software simuation as the only option for most independent student teams and similar groups. We designed CLS as an end-to-end modular framework where we could test any control and estimation algorithm of our choice.

My work on the CLS framework involved determining the system-wide timesteps so that the simulations were accurate, while also keeping the computational requirements of the simulation in check. This was made particularly tricky by magnetorquers that took a PWM wave as an input as well as the nonlinear dynamics of the satellite.