Civil aircraft automatic landing guidance based on cascaded fractional-order proportional-integral-derivative with an intelligent parameter optimizer

This article presents an automatic landing control system integrating cascaded fractional-order proportional-integral-derivative (CFOPID) controller with an intelligent parameter optimizer to address the precision and robustness demands of modern aircraft landing systems. Specifically, the dual-layer fractional-order controllers are employed to independently govern aircraft attitude and trajectory, leveraging the enhanced disturbance rejection and adaptability of fractional calculus. Subsequently, a vertical speed-based longitudinal landing guidance strategy is introduced, which utilizes aircraft’s real-time ground speed to generate the guidance command, enabling rapid correction of trajectory deviations caused by wind disturbances. Moreover, an enhanced whale optimization algorithm with dynamic adaptation mechanisms (EWOA) is developed to tune the controller parameters, ensuring optimal control performance under the given criterion. Therein, EWOA incorporates the adaptive convergence control strategy, the composite perturbation strategy, and the diversity-aware adaptive mutation strategy to enhance its optimization capability. Extensive simulations demonstrate that the developed CFOPID-based automatic landing control system exhibits robust landing trajectory tracking performance against wind disturbances and model uncertainties. The Monte Carlo statistical results show that the altitude error can be maintained within ±1 m, and the and the landing sites are clustered within a 30m range.