超低空空投货物出舱过程的动态逆鲁棒控制

Robust Dynamic Inversion Control for Cargo Extraction During Airdrop at Super Low Attitude

针对运输机在执行超低空空投任务时,地面效应的作用使飞机的气动特性发生改变,货物向舱门的移动过程使飞机的受力和力矩发生变化,货物出舱过程和地面效应的作用使飞机姿态和轨迹都大幅度偏离空投前的稳定飞行状态,如果控制失当,极易使飞机振荡发散,导致飞行事故的问题,设计一控制器保证超低空空投货物出舱过程中运输机的稳定性和安全性。由于被控对象是一个多变量耦合且参数变化的非线性系统,提出了一种基于动态逆理论和鲁棒控制理论的解决方案,控制器内环采用动态逆方法使系统解耦线性化,外环采用H∞鲁棒控制方法解决不确定性问题。仿真结果表明,该控制器能够很好地保持飞行速度和轨迹、稳定飞机姿态,具有良好的控制效果,且对于系统不确定性具有较强的鲁棒性。

The control problem of aircraft aerodynamic characteristics subjected to the ground effect during airdrop at super low attitude is considered,and the changes of the forces and the moments act on the aircraft with inner cargo extraction are analyzed.Cargo extraction and ground effect would lead a large-scale deviation from the original flight states,especially for the attitude and trajectory.A catastrophic accident would probably occur for the divergent oscillation on plane if posing improper operations.A controller is designed to keep transport aircraft in stabilization and safety in cargo extraction during airdrop at super low attitude.Considering that the plant is a multivariable coupled nonlinear system with varying parameters,a methodology based on the nonlinear dynamic inversion theory and robust control theory is presented.The inner loop of the controller adopts nonlinear dynamic inversion method to counteract the object nonlinear factors,and the H∞ robust control technique is utilized to guarantee robustness to uncertainties in the outer loop.The simulation results show the effectiveness and robustness of the proposed combined controller.