基于飞行力学的惯导轨迹发生器及其在半实物仿真中的应用

Trajectory generator of SINS on flight dynamics with application in hardware-in-the-loop simulation

讨论了在高超声速飞行器半实物仿真中,使用飞行器六自由度模型生成捷联惯导轨迹发生器的方案,使半实物仿真中的捷联惯导系统与飞行力学六自由度模型和飞行控制系统有机地融合到一起。介绍了六自由度模型的坐标系定义,描述了发射坐标系下由32个方程组成的高精度六自由度模型。指出了六自由度模型中惯性器件测量的比力和角速度理论值,比力和角速度是由飞行器飞控系统作用后所产生各种力和力矩的综合结果,而不同于传统轨迹发生器中由事先设定的速度和姿态变化而得。将发射坐标系下的导航信息推导到高超声速飞行器需求的当地水平导航坐标系下。数字仿真表明,提出的轨迹发生器满足高超声速飞行器半实物仿真的算法精度要求;半实物仿真表明,捷联惯导系统与六自由度模型、飞行控制系统能够有机结合,导航结果精度满足指标要求,支撑了高超声速飞行器飞控系统的性能指标评估。

How to generate trajectory profile of strapdown inertial navigation system(SINS) based on flight dynamics is discussed in the hardware-in-the-loop(HWIL) simulation of hypersonic vehicle, which makes SINS work together in harmony with the six-degree-of-freedom(6DoF) model of hypersonic vehicle and flight control and guidance system. Firstly, the definition of coordinate systems in 6DoF model is introduced. Then the high-precision 6DoF model with 32 equations is presented in launch centered earth-fixed(LCEF) coordinate system. The theoretical value of the specific force and the angular velocity measured by inertial measurement unit(IMU) in 6DoF model is given. The vector of specific force and the angular velocity is the combined result of a variety of forces and moments by the command of flight control system during flight, which is different from the traditional trajectory generator whose specific force and angular velocity are obtained from velocity and attitude changes set in advance. The navigation information in LCEF frame is converted to local east-north-up(ENU) frame to meet the requirement of hypersonic vehicle. The digital simulation result shows that the trajectory generator meets the requirement of algorithm accuracy in HWIL simulation of hypersonic vehicle. The HWIL simulation indicates that SINS, 6DoF model, flight control and guidance system can work together harmoniously, and the accuracy of SINS satisfies the requirement of navigation which can support the evaluation of the flight control system performance of hypersonic vehicle.