面向飞行器交会对接应用的载波相位差分技术研究

Research on GNSS carrier phase differential technique for spacecraft rendezvous and docking

GNSS引导两飞行器交会对接的前提是实时可靠地估计相位模糊度。针对卫星和飞行器的高动态性所引发的频繁换星问题,提出一种实时递归相位模糊度估计方法。该算法能够有效处理失锁所造成的卫星起落现象,同时充分利用历史观测与当前观测方程中部分模糊度分量的关联性,使得模糊度估计的成功率对可见卫星数目的减少不敏感。为了验证该算法在空间飞行器对接中的精度和成功率,采用GPS模拟器仿真两飞行器近程导引段和最终逼近段的过程,应用新算法实时估计两飞行器间相对位置,精度达到亚厘米级水平,成功率在可见星数递减时依然渐进逼近100%。

The premise of guiding two aircrafts with GNSS is the real-time and reliable estimation of phase ambiguity.To deal with the frequent satellite setting and rising caused by high dynamic movement of satellite and aircraft,one new method was presented for real-time and recursive phase ambiguity estimation.It handles frequent satellite setting and rising due to loss of lock.Also,by utilizing the ambiguity relevance of past observation and current observation,the success rate of integer ambiguity estimation is not sensitive to the number of satellite setting and rising.In order to verify the accuracy and the success rate of this algorithm in the application of the spacecraft rendezvous and docking,based on GPS simulator,the rendezvous and docking was simulated for short range guidance phase and the final approach phase of two aircraft.Then the new algorithm was applied to estimate the relative position between the two aircrafts using the simulation data,and it shows that the relative position precision achieves the sub-centimeter level and the success rate was still gradually approaching 100% when the number of visible satellites decreased progressively.