非完整约束的OD/SINS自适应组合导航方法

在地面车载组合导航GNSS/OD/SINS中，全球导航卫星系统（GNSS）信号容易受到环境的干扰甚至发生中断，将非完整性约束（NHC）应用于里程计（OD）/捷联惯性导航系统（SINS）组合，可以有效抑制GNSS信号中断期间组合导航系统的误差发散。通常NHC的噪声设定基于固定的经验值，然而在实际运动过程中，车辆运行轨迹复杂多变，其运动状态不能完全满足NHC前提假设，经验给定的噪声无法准确反映车辆实际运动情况。为此，本文分析了NHC噪声与车辆运动状态的关系，构建了一种基于车辆运动状态的NHC噪声自适应方法。通过所选场景的实测数据验证表明：采用噪声自适应的NHC/OD/SINS组合导航结果相比于固定噪声的NHC/OD/SINS组合，在GNSS信号中断110 s、车辆连续转弯的情况下，最大水平位置误差减小了68.4%；在GNSS信号中断74 s、车辆直线行驶的情况下，最大水平位置误差减小了87.3%；能较好地抑制GNSS中断期间组合导航系统的误差发散。

OD/SINS adaptive integrated navigation method with non-holonomic constraints

In the ground vehicle integrated navigation GNSS/OD/SINS,the global navigation satellite system(GNSS)signal is susceptible to environmental interference or even interruption.The non-holonomic constraint(NHC)is applied to the odometer(OD)/strap-down inertial navigation system(SINS)combination,which can effectively suppress the error divergence of the integrated navigation system during the GNSS signal interruption.Usually,NHC’s noise setting is based on a fixed empirical value.However,the trajectory of the vehicle is complex and changeable during actual movement,and its motion state cannot fully satisfy the NHC premises and assumptions.The noise given by experience cannot accurately reflect the actual vehicle motion.Therefore,this paper analyzes the relationship between NHC noise and vehicle motion state,and constructs a NHC noise adaptive method based on vehicle motion state.Validation of the real-world experiments of the selected scene shows that the result of the noise-adaptive NHC/OD/SINS combined navigation is compared with the fixed-noise NHC/OD/SINS combination,when the GNSS signal is interrupted for 110 s and the vehicle turns continuously,the maximum horizontal position error is reduced by 68.4%;when the GNSS signal is interrupted for 74 seconds and the vehicle is traveling in a straight line,the maximum horizontal position error is reduced by 87.3%;the error divergence of the integrated navigation system during the GNSS interruption can be better suppressed.