Magnetic sliding mode attitude controller design with momentum exchange augmentation

A magnetic sliding mode attitude controller is augmented by momentum exchange to improve the steady state performance of the control system. The sliding mode controller is designed based on the equivalent control approach and by using a novel sliding surface vector that is proposed specifically to the purely magnetic attitude control problem. The augmentation is fulfilled by making a reaction wheel triad to produce only the component of the continuous equivalent control vector that is along the local geomagnetic field vector. The result is a control system that is still robustly stable and has two times less steady state error with very little additional energy consumption.