基于舵面位置反馈的实用非线性控制分配方法

针对飞机在自主起降、大迎角飞行时力矩系数与舵面偏角之间的非线性和耦合性问题,以无尾飞翼飞机(TFWA)为对象,提出了一种实用新型的基于舵面位置反馈的非线性控制分配方法。该方法通过舵面位置反馈,在期望三轴力矩系数中除去前一拍舵面偏角产生的非线性三轴力矩系数,从而将非线性控制分配问题转化为线性控制分配问题来求解。证明了该方法具有一致渐近稳定性,且其稳态误差为0,并分析了该方法的可行性。通过与序列线性规划、序列二次规划和遗传算法等非线性控制分配方法进行数字仿真对比,突显了该方法精度高、解算快的特点;同时对该方法进行了基于伪逆法、不动点迭代方法和相邻面搜索方法的数字仿真,说明了其处理非线性控制分配问题的有效性。以TFWA、F18等为对象,在xPC-DSP半物理仿真平台上验证了该方法具有通用性强、实时性好的优点。 

Practical nonlinear control allocation method based on feedback of position of surface

To focus on the problems of nonlinearity and coupling between the moment coefficients and the surface deflections when the aircraft autonomously takes off,lands and flies with high angles of attack,a practical and novel nonlinear control allocation method based on feedback of position of surface was proposed for tailless flying wing aircraft (TFWA). The nonlinear moment coefficient of the surface deflection in previous sampling interval was removed from the desired three-axis moment coefficients by feedback of position of surface. Thus the nonlinear control problem was transformed into the linear control allocation problem and was solved. Unanimous asymptotic stability of this method was proved and steady state error was zero; the feasibility of this method was also analyzed. Comparisons of digital simulation were done with sequential linear programming,sequential quadratic programming and genetic algorithm,and results prove the high accuracy and fast computing speed of this method. Efficiency of this method to solve nonlinear control allocation problem was verified by the digital simulations of pseudo-inverse method,fixed-point iteration and neighbor search method. Finally,strong generality and good real-time performance of this method for TFWA and F18 were demonstrated on the xPC-DSP semi-physical simulation platform.