Overactuated multirotors have more actuators than needed for the wrench they must produce. Allocation schemes that greedily maximize a readiness metric can produce commands that jump between disconnected optimal solutions, requiring actuator rates that no motor can physically deliver. Effort-minimizing schemes are smoother but cannot guarantee that the system keeps enough wrench-rate authority — the ability to change its wrench quickly — above any certified level.
Silano's approach treats authority as a forward-invariant quantity using a control barrier function on the log-determinant of a drag-aware actuator-authority co-metric. The barrier is enforced at torque level by a quadratic program in the allocation null space. A single design inequality makes the certified set compact and strictly inside the actuator box, and the readiness cost of deactivating a rotor is given in closed form as ln(n/(n-m)) for symmetric designs. An alignment ratio tells when exact tracking is possible; otherwise wrench error is bounded by O(ρ^{-1/2}). A robust variant handles motor-parameter uncertainty with a closed-form floor shift.
Experiments on a hexarotor and a fully actuated octorotor show the closed-form gap matches simulation to machine precision. Across 300 randomized missions, greedy maximization violated the certified floor in up to 51% of authority-scarce missions, while the proposed filter never left the certified set and committed a 79× smaller wrench error in the hardest moment reversal. The robust variant held the floor on all 150 perturbed plants, and a high-fidelity simulation with measured propeller and motor data showed the floor holds under unmodeled aerodynamics, electrical limits, and delay.