Linear Parameter Varying Control for a Foldable Quadrotor

This work addresses the control problem of a foldable quadrotor whose in-flight arm reconfiguration changes its moment of inertia. A Linear Parameter Varying (LPV) controller is first designed to maintain consistent performance across configurations, but its computational cost limits its use on low-cost autopilots. Based on frequency domain analysis, we approximate the LPV with a low-order controller, akin to an adaptive PID, achieving similar response at lower complexity. Simulations and experimental tests on a Cortex M3-based platform, using both fixed-point and doubled-precision implementations, show similar behavior. The approach approximates LPV-like performance with PID-level efficiency, enabling real-time deployment on resource-constrained UAVs.