飞行器制导控制半实物系统采样步长的优化设计

为了提高飞行器制导控制系统半实物仿真的仿真精度,提出通过合理选择采样步长,优化仿真实时性来协调系统计算能力与仿真精度之间关系的思想。建立了制导控制半实物仿真系统的模型,依据采样控制原理推论出约束半实物仿真采样步长的主要条件。依据优化原则,建立了满足数值计算精度及稳定性的约束条件,推导出优化的采样步长。最后,对制导控制系统进行半实物仿真。系统软件采用C语言编写了飞行器的六自由度运动方程,硬件为三轴转台系统和Vxworks操作系统的嵌入式仿真机,并在转台内框加入陀螺实现稳定控制。结果表明,在优化设计的采样步长1 ms下,系统的实时性能够满足制导控制仿真精度及稳定性要求。在不增加系统软硬件负担的情况下,提升了半实物系统的置信度。

]Optimal design of sampling steps in hardware-in-loop simulation for aircraft guidance and control

To improve the simulation accuracy of the Hardware-in-loop Simulation (HILS) of a guidance and control system, an idea is proposed to well balance the relationship between calculation ability and simulation accuracy of the system by selecting reasonable sampling steps and optimizing real time ability of the system. A mode for the HILS of guidance and control system is established, and the restraining conditions for sampling steps of the HILS are deduced according to the sampling principle. Furthermore, the restraining conditions are optimized and the optimized sampling steps are determined to implement the restraining conditions of calculation accuracy and stability. Finally, a HILS is carried out for the guidance and control system. In the simulation, the aircraft six Degree-of-freedom (6DOF) differential equation is written by C MEX S-function, and the hardware consists of a three axis turntable, a real-time calculator and a flight-motion-simulator. It is concluded that the HILS can meet the requirement of guidance and control systems for the simulation accuracy and real time stability in an optimized sampling step of 1 ms and can improve the simulation accuracy without adding any software or hardware.