时钟模型辅助的惯性/卫星紧组合导航算法研究

针对卫星信号受到遮挡或者干扰、卫星接收机收星数不足的问题,提出了一种时钟模型辅助的惯性/卫星紧组合导航算法。通过正常紧组合状态下的钟差、钟漂估计值建立钟差和钟漂的数学模型,在可见卫星少于4颗时,用时钟模型计算得到的钟差和钟漂作为系统钟差、钟漂的真实值引入观测信息中,并省去状态变量中的钟差和钟漂项,增加了系统的可观测性。最后,通过采集跑车试验数据进行了离线数据仿真试验。试验结果表明,提出的时钟模型辅助的惯性/卫星紧组合导航算法在可见卫星不足的情况下取得了良好的效果。

A Inertial/Satellite Tightly Integrated Navigation Algorithm Assisted by Clock Model

The satellite receiver can't receive enough satellite signals when the satellite signal is blocked or jammed.Aiming at the problem,an inertial/satellite tightly integrated navigation algorithm assisted by clock model is proposed.The model of clock error and clock drift is established by estimating the clock error and clock drift in the normal condition of tightly integrated navigation system.When the number of visible satellite is less than four,the clock error and clock drift calculated by the clock model are introduced into the observed information as the true values of the system clock error and clock drift,and eliminate the clock error and clock drift in the state variables,which increases the observability of the system.Finally,the off-line simulation through the acquisition of vehicle test data is designed.The simulation results show that the inertial/satellite tightly integrated navigation algorithm assisted by clock model achieves good results in case the satellite receivers can't receive enough satellite signals.