作动器速率饱和时的PIO抑制方法

 作动器速率饱和会产生附加的时间延迟, 使系统稳定性大大降低, 并增加了驾驶员诱发振荡( PIO) 的趋势。为防止作动器速率饱和, 在飞控系统中一般设置了软件速率限制器。对比分析了3 种软件速率限制器, 探讨了它们的开环和闭环特性, 从研究角度出发, 提出了某型飞机在出现低液压故障情况下的PIO 抑制方案。非线性六自由度仿真结果表明, 该方案明显改善了算例飞机在严重低液压故障时的动态响应, 降低了PIO 趋势。

Method to Prevent Pilot-Induced-Oscillations due to Actuator Rate Limiting

When actuators are saturated, the additional time delay would occur, which drastically reduces the stability margins of the closed loop and increases the risk of pilot-induced oscillations (PIO). The software rate limiters are usually used in flight control laws to prevent the actuator saturation. This paper describes the open loop and closed loop properties of three kinds of software rate limiters. A method is proposed to prevent the PIO due to actuator saturation for the example aircraft. The six degrees of freedom (SDOF) flight simulation results demonstrate that this method improves significantly the aircraft closed loop stability and flying qualities, and reduces the PIO tendency.