Fractional order sliding mode observer-based control (FOSMOC) is a specialized control technique that combines the concepts of fractional calculus, sliding mode control, and observer design. While I don't have specific information on its application to interplanetary science missions beyond September 2021, I can provide a general understanding of how it might enhance the robustness of multi-motor systems for such missions.
Robustness in the Face of Uncertainties: Interplanetary science missions involve complex and dynamic environments with various uncertainties, such as changes in gravitational forces, atmospheric conditions, and external disturbances. FOSMOC can enhance robustness by allowing the control system to handle these uncertainties effectively. Fractional calculus introduces non-integer order dynamics, enabling the controller to capture complex behaviors and adapt to changing conditions.
Sliding Mode Control: Sliding mode control is known for its robustness against uncertainties and disturbances. It forces the system's state trajectory to slide along a predefined manifold, ensuring convergence to the desired state despite uncertainties. Fractional order sliding mode control adds an additional degree of freedom by allowing the sliding surface to have fractional derivatives, which can provide better adaptation to varying conditions.
Observer-Based Control: Observers are used to estimate unmeasured or difficult-to-measure states of a system. In interplanetary missions, obtaining accurate sensor measurements can be challenging due to communication delays, limited resources, and sensor noise. Observer-based control, when combined with fractional order dynamics, can provide more accurate state estimates, leading to improved control performance even when measurements are unreliable.
Multi-Motor Systems: Interplanetary science missions often involve spacecraft with multiple motors or actuators responsible for various tasks such as propulsion, attitude control, and trajectory adjustments. Coordinating and controlling these motors is crucial for the success of the mission. FOSMOC can offer robust coordination and control by simultaneously addressing the uncertainties and dynamics of multiple motors.
Non-Integer Order Dynamics: Fractional order dynamics allow the control system to capture and model more complex behaviors that might not be well-described by traditional integer-order control methods. This added flexibility can enhance the controller's ability to adapt to intricate interactions and behaviors within multi-motor systems.
Reduced Chattering: Sliding mode control is prone to chattering, which refers to high-frequency oscillations around the sliding surface. The use of fractional order sliding mode control can help reduce chattering, leading to smoother control actions and potentially prolonging the lifespan of mechanical components in the multi-motor system.
It's important to note that the successful implementation of FOSMOC for interplanetary science missions requires careful system modeling, parameter tuning, and thorough testing in relevant environments. Additionally, advancements and improvements in control techniques may have occurred after my last knowledge update in September 2021, so I recommend consulting the most recent literature and research in the field for the latest developments.