Gain-Scheduled Autopilot Design and Validation for an Experimental Guided Projectile Prototype

This paper investigates the design and validation of a gain-scheduled skid-to-turn autopilot for an experimental canard-guided, fin-stabilized 80-mm-guided projectile prototype in a hardware-in-the-loop (HIL) wind tunnel-based setup. The projectile dynamics are a priori unknown and are determined from open-loop system identification experiments conducted on the test setup. To this end, a nonlinear airframe model is discussed and considered for linearization around equilibrium operating points. The linear model parameters are estimated from several data collection experiments, resulting in a family of linear models. This knowledge is leveraged in a second step to compute a family of robustly stable multiobjective disturbance-rejection and reference-tracking controllers, which are implemented on the HIL test setup using a zero-pole gain interpolation scheme. The time-domain performance of the autopilot is finally assessed by the means of numerical simulations and experimental results gathered from the test setup, demonstrating the excellent suitability of the proposed approach