ESA GNC Conference Papers Repository
Spherical Air-bearing AOCS testbed with parasitic moments of inertia cancelation
A spherical air-bearing AOCS testbed, equipped with an external torque generating subsystem, is proposed. Such a system could enhance satellite hardware testing, verification, and validation capabilities of typical air-bearing testbeds. The externally generated torque can be used for simulating environmental disturbance torques, but more importantly it can actively modify and correct the dynamical response of the system under test (SUT). This allows for correction of the SUTs experienced moments of inertia (MOI), or its continuous alteration to simulate complex mechanical processes, such as panel deployment or tether dynamics. This study is focused on the cancellation of the parasitic MOI, which originate from the testbeds spherical enclosure. Capability to remove the parasitic MOI would allow building testbeds for use with flight ready nanosatellites that would provide them with nearly realistic dynamics experience, enabling end-to-end validation testing of attitude maneuver scenarios. The air-bearing testbed is modeled in a numerical simulator. The simulation is used for the development of the control algorithms for the parasitic MOI cancellation using external torque generating subsystem. Performance of the testbed and algorithms is characterized and presented.