Testing the attitude determination and control of a CubeSat with hardware-in-the-loop

Abstract

This thesis presents a methodology for testing the attitude determination and control of a CubeSat within a constrained environment. This approach first evaluates the concept of operations of the satellite mission, then takes into account the limitations of the test environment, formulates test plans that can validate algorithms with hardware-in-the-loop, and presents a model by which these tests can be evaluated. The Microsized Microwave Atmospheric Satellite (MicroMAS), a dual-spinner 3U CubeSat, is used as a case study to demonstrate both the overall methodology and the validation model. Laboratory experiments were performed with a one-degree-of-freedom rotation test set-up inside of a Helmholtz Cage magnetic field simulator. The theoretical development of the control algorithms and design choices are discussed. A software model of the controller, hardware, and test environment was used to evaluate the results from these experimental tests. The results showed that, using the designed control system, the satellite model is able to successfully detumble itself, achieve a desired angular rotation, and compensate for the momentum introduced by a rotating payload. The test data are analyzed and show that the control system is able to meet the mission pointing requirements of maintaining within 1 degree (3[sigma]) deviation from the nominal LVLH attitude after its slew maneuver, before payload spin-up. During its science operation mode, the tests showed a pointing deviation from nominal attitude of about 2.2 degrees (3[sigma]). The details of the constraints and limitations of the test environment and their impacts are discussed.