To merge sensing acquisition and processing in a unified AOCS function and actuator commanding on another AOCS function, to simplify AOCS architecture and reduce development cost, improving efficiency and modularity for Earth Observation smallsats

AOCS mode switching is implemented on many spacecraft to perform progressive transition from coarse pointing to fine pointing, or to perform slews, using different combinations of sensors, actuators and control algorithms. This standard architecture is at a cost of a certain complexity, with consequences on development and validation cost.The proposed activity consists in hybridizing different sensors to get a virtual unified sensor. Similarly, the actuators would be merged and controlled through a virtual actuator distributing the command to each of the physical actuators.). The control function using measures from the virtual sensor and sending commands to the virtual actuator, will rely on adaptive control techniques (e.g. Linear Parameter Variaiton techniques) to fulfill mission performance/robustness.The actuators could encompass thrusters, wheels, magnetic torquers but also proof mass actuators to perform high frequency control of micro-vibrations. The sensors could be star tracker, gyros, magnetometer and sun sensor. The control algorithm bandwidth should make benefit of the virtual sensor to increase as much as possible the control bandwidth from low frequency (e.g. solar radiation pressure), to high frequency perturbation, including flexible modes dynamics.The activity is dedicated to Earth Observation Smallsats missions, taking into account their specifics in terms of sensor and actuator suites, as well as AOCS design drivers and mission/operations constraints.The activity encompasses the following tasks:- Existing application case selection including performance requirements, sensors and actuators selection, AOCS subsystem /modes design- Sensors and actuators hybridization - "Single Mode" AOCS subsystem design- Simulator development- Validation test campaign- Conclusion and way forward