Active control of road vehicle’s drag for varying upstream flow conditions using a Recursive Subspace based Predictive Control methodology

The paper empirically demonstrates a recursive subspace predictive control (RSPC) scheme that maintains the Windsor body’s base-pressure distribution near its zero-yaw reference across β ∈ [−5°,5°], shows ≃5% mean improvement under a sinusoidal yaw at St ≃ 10⁻³, and documents deviations for a stricter reference beyond |β| ≈ 2–3° due to actuator limits, but it does not furnish formal closed-loop guarantees or robustness proofs (e.g., recursive feasibility, ISS, tube tightening) beyond Assumption 1 and an explicit QP formulation with integral action . The model solution supplies such guarantees under clear hypotheses (slow LPV drift with dwell-time, PE via IV-subspace ID, tube-based tightening, terminal ingredients, calibrated link Cb ≈ κ y3), and its conclusions align with the paper’s empirical findings, rendering it correct under its stated assumptions.