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针对直升机配平模型为多元且初始值难以确定的非线性方程组,以及全局最优解不唯一等问题,发展了一种基于遗传算法/拟牛顿法的高效混合迭代算法。介绍了直升机各个模块动力学方程。其中在旋翼建模中,考虑实际飞行环境下桨叶的运动和操纵特性,以动态入流和叶素法为理论基础,建立了具有配平特性的旋翼气动力模型。基于直升机飞行仿真动力学模型,详细推导了前推/后拉的配平变量和约束方程。通过构造目标函数,将全机配平问题转化为优化问题。通过计算UH-60A直升机在前推/后拉的配平解,并与飞行测试数据进行比较验证。结果表明,前推配平结果与飞行数据有偏差,后拉配平结果与飞行数据吻合。旋翼非定常气动特性是引起总距和脚蹬配平计算误差的主要原因。建立的配平算法适用于直升机不同稳定飞行条件下的仿真。
Aiming at the problems that the helicopter trim model is multi-element and the initial value is hard to determine, and the global optimal solution is not unique, an efficient hybrid iterative algorithm based on genetic algorithm / quasi-Newton method is developed. The dynamics equations of each module of helicopter are introduced. In rotor model modeling, considering the motion and steering characteristics of blades under actual flight conditions, the rotor aerodynamic model with trim characteristics is established based on dynamic inflow and valence factor method. Based on the helicopter flight simulation dynamics model, the pre-push / pull-back phasing variables and constraint equations are deduced in detail. By constructing the objective function, the problem of optimizing the whole machine is transformed into the optimization problem. By computing the UH-60A helicopter in the push / pull the balance solution, and compared with the flight test data validation. The results show that the result of forward push leveling is deviated from the flight data, and the result of back pull leveling is consistent with the flight data. The unsteady aerodynamic characteristics of the rotor are the main causes of the calculation error of the total distance and the pedals. The built-in algorithm is suitable for the simulation of helicopter under different stable flight conditions.