利用实际飞行数据插值的INS/GNSS组合导航仿真轨迹发生器

针对INS/GNSS组合导航仿真中捷联惯导系统陀螺、加速度计信号高精度模拟问题，提出基于实际飞行数据插值的动态轨迹解析生成仿真算法。对转换到地心惯性坐标系中的载体姿态、位置和重力场数据进行关于时间的样条函数插值，得到载体坐标系下陀螺角速率、角增量以及加速度计比力积分增量的高精度分段解析表达式。使生成的陀螺、加速度计信号符合载体运动学和动力学特性，反映杆臂效应影响，同时与经事后处理的实测GNSS伪距、伪距率等数据特征保持一致。提出四元数约束插值算法，其可满足四元数解析插值时范数为1的约束限制条件。基于某实际无人机飞行数据，验证了所提算法的有效性，其完全满足组合导航动态仿真精度要求。该算法也适用于其他高精度高动态导航系统和刚体运动控制仿真中的角运动、线运动传感器信号模拟。
An analytic dynamic trajectory generating algorithm based on real flight data interpolation was proposed for INS/GNSS integrated navigation simulation, in order to solve the problem of generating high-precision simulated signals of gyros and accelerometers in a strapdown inertial navigation system. Accurate piecewise analytic expressions of angular rates, angular increments and specific force integral increments in body frame were obtained on the basis of the spline function interpolation for the vehicle′s attitude, position and gravity data in the earth centered inertial frame. The simulated signals of gyros and accelerometers were coincident not only with the vehicle′s kinematics and dynamic characteristics, but also with the characteristics of post-processed GNSS′s pseudo-ranges and their rate measurements. The influence of the lever arm effect of an inertial measurement unit was also simulated. A constrained analytic quaternion interpolation algorithm was proposed under the restrictive condition in which the norm of the interpolated quaternion should be 1. Based on the real flight data of an unmanned aerial vehicle, it is proved that the accuracy and the effectiveness of the proposed algorithm can meet the requirements of dynamic simulation of integrated navigation. The algorithm can also be used in other simulations, such as high-precision high-dynamic navigation and rigid body motion control, in which the simulated sensor signals in angular and linear motion are needed.