The Observability Analysis Of Transfer Alignment Of SINS

Theoretical study of transfer alignment mainly designs kalman filter of alignment model.Usually observability analysis has to be implemented before designing kalman filter to determine the kalman filter effect.The linear and constant system is easy to be analyzed,but linear and time-dependent system is difficult to cope with.However,linear and time-dependent system is occurred using transfer alignment.So observability analysis of system becomes the important part of transfer alignment research.This research deduced SINS's error model base on the SINS's working theory,and introduced discrete Kalman filter's equation.Then,analyzed the theory of transfer alignment technology,then designed the Kalman filter model of angular rate matching method and velocity matching method,established the foundation observability analyzing.On the base of the Kalman filter model of angular rate matching method and velocity matching method,this research did the emulation and observability analyzing to them,studied their selves's characters and adaptive sailing conditions, proved that angular rate matching method should put dynamic distortion into state vector to estimate when been affected by the ship hull dynamic distortion,and we would acquire higher estimating precision-when ship had a wide range swaying, ship's linear movement didn't much effect to it.But velocity matching method could heighten heading uncertainty's estimating precision when had wide range linear movement,ship's swaying could increase accelerometer's observable degree.We apply PWCS theory to transfer alignment of SINS,and analyse its observability and degree of observability using SOM matrix instead of TOM matrix.For angular rate matching method and velocity matching method,we use SVD method to analyse the observability and degree of observability on various moving states in the thesis.Using state equation decoupling method andКузовков judgement method,the observability and degree of observability during velocity matching method are analyzed in detail.Unobservable state variables can be more efficiently determined via combining use ofКузовковjudgement method with the SVD method.