PID控制器与CFD的耦合模拟技术研究及应用

发布时间：2018-02-11 01:09

本文关键词： PID控制器数值虚拟飞行 CFD/RBD/FCS耦合模拟快速机动数值模拟　出处：《航空学报》2016年08期 　论文类型：期刊论文

【摘要】：飞行控制系统(FCS)与计算流体力学(CFD)的耦合求解是一个崭新的研究领域。传统的飞行控制系统的工程仿真方法依靠气动力模型或气动力数据库得到不同飞行姿态的气动力;而当前方法通过耦合求解Navier-Stokes方程和刚体动力学方程(RBD)以获取飞行器运动过程实时流场和非定常气动力。由于充分反映了气动力的非定常、非线性效应,因而从根本上保证了飞行控制系统仿真的精度。以方形截面导弹俯仰姿态控制为例,首先给出了系统的传递函数,并基于系统在单位阶跃舵偏操纵下的开环响应特性,提出了传递函数的修正方法,进而设计了该外形俯仰姿态控制的PID控制器。数值模拟了不同控制参数时,P控制器、PD控制器和PID控制器的控制效果。针对不同的控制指令,根据建立的控制律,数值模拟了飞行器在PID控制器作用下的实时响应过程,最终成功实现了对飞行器的俯仰姿态控制。研究发现,当飞行器作慢速机动时,工程仿真与CFD数值计算的结果吻合很好,两种方法可以互相验证;但快速机动时,两种方法给出的结果差异明显,基于CFD的耦合模拟方法由于模拟了飞行器运动和舵面偏转导致的非定常流动过程,其结果比基于静态气动力的工程方法的可靠性更高。在大攻角和快速机动等非定常效应较强时,采用CFD方法评估和验证飞行控制系统是很有必要的。
[Abstract]:The coupling solution of flight control system (FCS) and computational fluid dynamics (CFDs) is a new research field. The traditional engineering simulation method of flight control system relies on aerodynamic model or aerodynamic database to obtain aerodynamic force of different flight attitude. However, the current method can obtain the real time flow field and unsteady aerodynamic force in flight vehicle motion process by coupling solving Navier-Stokes equation and rigid body dynamics equation, because it fully reflects the unsteady and nonlinear effect of aerodynamic force. Therefore, the simulation accuracy of flight control system is guaranteed fundamentally. Taking the pitch attitude control of square cross-section missile as an example, the transfer function of the system is first given, and based on the open-loop response characteristics of the system under the control of unit step rudder deviation. A modified method of transfer function is proposed, and then the PID controller for pitch attitude control is designed. The control effects of PD controller and PID controller are numerically simulated under different control parameters. According to the established control law, the real-time response process of the aircraft under the action of the PID controller is numerically simulated, and the pitching attitude control of the aircraft is successfully realized. The results of engineering simulation and CFD numerical calculation are in good agreement, and the two methods can verify each other, but the difference between the two methods is obvious in fast maneuvering. The coupling simulation method based on CFD is used to simulate the unsteady flow process caused by the motion of the aircraft and the deflection of the rudder surface. The result is more reliable than the engineering method based on static aerodynamic force. When the unsteady effects such as large angle of attack and fast maneuvering are strong, it is necessary to use CFD method to evaluate and verify the flight control system.
【作者单位】：中国空气动力研究与发展中心计算空气动力研究所;
【基金】：国家自然科学基金(11172315,91216203,11372341,11532016)~~
【分类号】：V249.1

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