Reliable Control for Flexible Spacecraft Systems With Aperiodic Sampling and Stochastic Actuator Failures

Area of Science:

• Aerospace Engineering
• Control Systems Theory
• Nonlinear Dynamics

Background:

• Flexible spacecraft exhibit complex nonlinear dynamics.
• Actuator failures, especially stochastic ones, pose significant challenges to spacecraft control.
• Existing control methods may be conservative in handling aperiodic sampling and system uncertainties.

Purpose of the Study:

• To develop a robust control strategy for flexible spacecraft with stochastic actuator failures.
• To address the challenges of aperiodic sampled-data control in nonlinear systems.
• To improve attitude stabilization and disturbance attenuation.

Main Methods:

• Approximation of flexible spacecraft dynamics using Takagi-Sugeno (T-S) fuzzy models.
• Modeling multi-stochastic failures via a time-continuous and state-discrete Markov chain.
• Introduction of a membership-sampling-dependent Lyapunov-Krasovskii functional (MSDLKF) to account for aperiodic sampling and fuzzy membership information.
• Design of reliable fuzzy controllers using linear matrix inequalities (LMIs).

Main Results:

• Achieved exponential attitude stabilization for flexible spacecraft under stochastic actuator failures.
• Ensured disturbance attenuation despite system uncertainties and failures.
• Demonstrated the feasibility and validity of the proposed control methods through a practical flexible spacecraft example.
• Reduced design conservativeness by incorporating sampling information into the control design.

Conclusions:

• The proposed fuzzy control approach effectively handles aperiodic sampled-data control for flexible spacecraft with stochastic actuator failures.
• The developed method provides robust attitude stabilization and disturbance attenuation.
• The use of MSDLKF and LMI-based controller design offers a promising direction for complex spacecraft control systems.