Fractional-order ILC-based adaptive integrated guidance and control of flight vehicles with system lag

This paper proposes an adaptive integrated guidance and control (IGC) method termed fractional-order PID-type iterative learning control (FoPILC), which aims to solve the issue of system lag in large maneuvering target interception system. Firstly, to address the shortcomings of recursive models in traditional IGC design, taking into account the sensor dynamic lag and unknown uncertainties, the interception model is represented as a complete high-order nonlinear system with no small angle assume. Secondly, the uncertain information is estimated, which is subsequently utilized in a high-order adaptive controller and integrated with the deviation feedback control to constitute the basic control strategy, and completely avoids the ‘differential explosion’ phenomenon caused by the backstepping method. More importantly, we introduce the FoPILC to update the control commands, which eliminates the influence of the system lag, and improves the accuracy of the impact angle constraint. Finally, the convergence of the control system is analyzed, and the simulation results are presented to demonstrate the effectiveness and superiority of the proposed IGC design.