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为进一步改善倾转旋翼机短距起飞单发失效后着陆轨迹优化的操纵策略,建立适用于倾转旋翼机单发失效后轨迹优化的增广飞行动力学模型并进行计算分析.首先,在基本纵向刚体模型的基础上建立关于操纵量的代数方程和微分方程组,形成增广飞行动力学模型,从而能反映出旋翼拉力系数、后倒角与驾驶员操纵杆量之间的关系,同时也能在轨迹优化中考虑到操纵系统特性对操纵量变化速度的限制,避免操纵量在优化过程中跳跃不连续;然后,采用直接转换法将着陆过程中的最优操纵策略和最优轨迹问题转化为非线性规划问题,并使用序列二次规划算法进行求解;最后,以XV-15倾转旋翼机为例,计算了短距起飞单发失效后安全着陆的最优解,并与相关文献数据进行对比.结果表明,在飞行路径、地速、旋翼转速和俯仰角的变化趋势与文献基本一致的情况下,需用功率、拉力系数与纵向周期变距杆位移等变化更加柔和,此外优化结果还包含了现有方法无法得到的操纵量和操纵速率信息.由增广飞行动力学模型得到的轨迹优化结果可以为单发失效时驾驶员实施安全着陆提供更多有用的依据.
In order to further improve the control strategy of landing trajectory optimization after single-rotor failure of tiltrot rotorcraft, an augmented flight dynamics model suitable for trajectory optimization of tilter rotorcraft after single failure is established and calculated.Firstly, Longitudinal rigid body model based on the establishment of algebraic equations and differential equations governing the formation of augmented flight dynamics model, which can reflect the rotor pull coefficient, chamfering and driver lever relationship between the amount of In the trajectory optimization, considering the characteristics of the control system to control the rate of change of the manipulated variable to avoid the jump in the optimization process, the discontinuity of the manipulated variable. Then, the direct manipulation method is used to convert the optimal maneuver strategy and the optimal trajectory problem during landing Which is a nonlinear programming problem and is solved by using the sequence quadratic programming algorithm. Finally, taking the XV-15 tilting rotorcraft as an example, the optimal solution to the safety landing after single-take-off failure is calculated and compared with the related literature data The results show that with the change trend of flight path, ground speed, rotor speed and pitch angle basically consistent with the literature, The coefficient is much softer than the change of the vertical period pitch shift rod, etc. In addition, the optimization result also contains the information of the manipulated variable and the manipulated rate which can not be obtained by the existing methods.The trajectory optimization result obtained by the augmented aerodynamic model can be the single failure Driver implementation of a safe landing to provide more useful basis.