Performance Enhancement of Large-Ship Transfer Alignment: A Moving Horizon Approach

Abstract

In shipborne Transfer Alignment (TA) applications, partial observability is one of the most important factors limiting convergence velocity. This paper proposes a new method of attributing weak observable states and lever-arm variables to a group of constraints in order to improve the observability of TA model. This yields the so-called Constrained Transfer Alignment (CTA) model which is uniformly observable even under zero-manoeuvre conditions. Within this framework, the Moving Horizon Estimation (MHE) and its stability analysis are also addressed. Finally, comparative simulation results are given to demonstrate the advantages of the proposed approach.

Sensor to sensor calibration of the integrated INS/vision navigation system

“…The standard pose estimation formulation is a strong nonlinear process. 16 For this analysis, the nonlinear system will be approximated at each time step as a linear system, always along with time-varying coefficients. Researchers usually use the Hermann approach to analyze the observability of nonlinear system.…”

Novel Transfer Alignment of Shipborne Gimbaled Inertial Navigation Systems

“…5) TA procedures are mature with theoretical research and modern navigation applications to numerous airborne, ground-based and naval systems. 6) A marked rise in TA has been witnessed to meet the increasing demands for quick reactions in different weapon systems.…”

“…[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] have achieved significant progress. The traditional and popular method used in TA technology is velocity match (VM).…”

“…With the advent of gimbaled INS for strategic weapons equipped in warships, some of these TA methods are not viable, as the operating principle of the gimbaled INS is different from the strap-down INS. [6][7][8] For the gimbaled INS, the gyros measure the platform rotational rate instead of body rotational rate in the strap-down INS, and the accelerometers measure the specific force in the platform frame instead of body frame in the strap-down INS. With these measurements, the missile-borne computer gives the command angular rate as output through navigation algorithm, and the platform is controlled by a servo mechanism to implement orientation in the inertial space or tracking the navigation coordinate frame.…”

Robust initial alignment algorithm for platform inertial navigation system on disturbance base

“…This kind of vibration disturbance is long duration, rapid changing and complex and its character include the frequency is time-varying, so the signal is typical nonstationary signal. There has typical way to process this kind of nonstationary vibration signal for initial alignment, that is to regard the vibration disturbance to a kind of high frequency random disturbance, it would be filtered on the process of INS initial alignment data pretreatment [3][4][5] . The energy character of vibration disturbance was analyzed by using the Wigner-Ville distribution (WVD) and was found to distribute at each frequency band, the filter can't filter the disturbance totally, Furthermore it is hard to establish the model to describe the disturbance character.…”