Constrained Stable Inverse Control of Discrete-Time Non-Minimum Phase MIMO Systems

Spacecraft with flexible appendages such as booms, solar arrays, or robotic arms require precise trajectory tracking for deployment and operation. However, feedback control is limited by bandwidth constraints and structural flexibility, degrading performance. Stable inverse control preemptively cancels internal dynamics but suffers from destabilizing zeros introduced during discretization. Additionally, aggressive inputs can saturate space-rated actuators with limited authority. Constrained optimization mitigates saturation while maintaining tracking accuracy. This paper extends stable inverse control techniques to discrete-time multi-input, multi-output (MIMO) systems with non-minimum phase behavior. A convex formulation using semidefinite programming ensures actuator feasibility and robust performance. Simulations on high-order MIMO models demonstrate improved tracking and stability under realistic constraints.