Research On The Error Model Of Airborne Celestial/inertial Integrated Navigation System

Airborne celestial/inertial automatic navigation system is the ideal choice for airborne navigation system because of its full autonomy and high precision when long-endurance. In which, airborne celestial navigation system is the guarantee of long-endurance high precision for integrated navigation system. The algorithm derivatives of positioning and attitude-measuring, the establishment of the error model and the analysis of the error of airborne navigation system are of great significance in the design process of airborne celestial/inertial automatic navigation system.In this paper, the composition of airborne celestial/inertial automatic navigation system is introduced. Based on the system characteristics, we establish the coordinate system of airborne automatic celestial/inertial navigation system, the transformation relations between the coordinate are discussed, and we derive the positioning and attitude-measuring algorithm for airborne celestial/inertial automatic navigation system.Then, we establish the positioning error model of airborne celestial/inertial automatic navigation system, and we analyze each error of the system. These errors include airborne celestial navigation system’s own error, installation error, reference error and other errors. There are a total of more than a dozen errors.Finally, we calculate the positioning error of airborne celestial/inertial automatic navigation system according to the Monte Carlo method. The results show, the positioning accuracy of airborne celestial/inertial automatic navigation system we designed can achieve 300m(CEP), which is adequate to meet the positioning requirements for long-endurance aircraft. The results also show that the greatest impact is the error of the three attitude reference providing by inertial navigation system in the dozen errors that impact the positioning accuracy of airborne celestial/inertial automatic navigation system. Their influence accounted for over 50% of the total positioning error for airborne celestial/inertial automatic navigation system. And the errors on the shock absorber and shafting are also very important.These analysis and calculation provide a theoretical foundation the next airborne celestial/inertial automatic navigation system design and precision promotion. And they also have a certain reference value for the engineering realization.