超低空空投牵引伞失效下的全局积分滑模控制

Global integral sliding mode control for ultra-low-altitude airdrop in extraction parachute failure state

针对超低空空投过程中发生的牵引伞失效故障情况下,影响载机飞行安全及空投任务的完成等问题,提出了二级迭代全局积分滑模飞行控制方法。首先分析了在牵引伞失效故障下载机的开环特性;然后在对模型进行反馈线性化处理的基础上,采用二级迭代全局积分滑模控制设计系统内环速度与俯仰姿态跟踪控制器,结合外环PID高度控制保持器完成整个飞控系统的设计,改善了系统的动态性能;最后通过仿真验证了控制器的优良性能,表明其应对故障状态具有很强的强鲁棒性。

To reduce the impact on the flight safety and the airdrop mission with the extraction parachute failure,a novel controller based on the global integral sliding mode control is designed. Firstly,the openloop characteristic of the carrier with extraction parachute failure was analyzed. Then,the system was decoupled and linearized using the nonlinear linearization theories of input-output feedback. On this basis,we designed the inner loop for velocity control and pitch control by applying the two-stage iterative global integral sliding mode control. Combining the inner loop controller with the outer loop PID flight altitude controller,we built the entire flight control system which improves the dynamic performance of the system. Simulation results show that the controllers have strong robustness in its corresponding fault state.