With the maturization of the cubesat market, the requirements for finer control over satellite attitude drives the development of higher performance Attitude Determination and Control Systems. (ADCS)

The ADCS uses reaction wheels as an actuation method, which in turn use brushless DC (BLDC) motors to rotate a heavy rotor wheel. BLDC motors use an external controller to drive armature currents, rotating the stator field, which in turn rotates the rotor.

The purpose of this MSc thesis is to improve rotor state estimation, improving reaction wheel performance by allowing for the implementation of more advanced control algorithms. This state estimation is improved through the development of a capacitive sensing encoder. This encoder was developed, a prototype built and tested. The encoder has an accuracy of 0.101 degrees, which is a 300x improvement over the currently used method of state estimation.