俯仰姿态保持模式下飞机结冰边界保护方法

在研究飞机结冰机翼和平尾失速机理的基础上，以飞机迎角作为关键参数，飞机俯仰指令作为指令参数，提出一种基于飞机自驾仪的结冰后边界保护方法.通过引入铰链力矩检测模块，提前告警飞机失速，为边界保护提供了裕度.建立飞机纵向动力学方程，针对俯仰姿态保持（PAH）模式下机翼失速进行了仿真计算.结果表明:结冰条件下，通过铰链力矩的检测，飞机能在失速迎角为2°之前，进入边界保护模式，增加飞行安全的裕度.通过控制指令的限制，自动驾驶模式下飞机迎角能保持在失速迎角之内. 

Envelope protection method for pitch attitude holding mode under flight icing conditions

An envelope protection method with autopilot systems was proposed based on the research of wing stall and tailplane stall under icing conditions. The angle of attack was identified as a critical parameter, and the pitch angle was identified as a command parameter. The detection of hinge moment coefficient could early warn aircraft stall and increase the margin of envelope protection. The flight longitudinal dynamics equation in pitch attitude holding (PAH) mode was built. Results show that, the envelope protection system works at the 2 degrees before the stall angle of attack through the detection of hinge moment under icing conditions, increasing the flight safety margin. With the control command limitation, the angle of attack of the automatic flight under icing conditions could be limited to the stall angle of attack.