عنوان مقاله [English]
In this paper, an inertial navigation system is designed based on non-orthogonal installation of sensors. In this design, which is done in an inertial navigation system attached to the body, unlike the conventional method of installing sensors vertically, the sensors, especially accelerometers, will have non-inverted sensitive axes during installation. It should be noted that the importance of calibration of inertial navigation blocks in navigation accuracy is very high and therefore we try to calibrate the inertial navigation block and its sensors as accurately as possible. For various reasons, the calibration coefficients of inertial sensors lose their validity over time, which necessitates their intermittent calibration. In this paper, a pre-launch calibration correction method is proposed that not only compensates for the need for repeated calibration of navigation blocks, but also reduces the navigation error due to initial positioning, ground gravity model and computational errors. . In this method, using local gravity acceleration and the speed of the earth, it is tried to compensate for the deviation in the calibration coefficients and some other errors in the time before launch. In addition, to solve the problem of non-observability of accelerometers perpendicular to the gravity vector, it is suggested to install non-invertebrate accelerometers. More details and calculations related to this method are given in the body of the article. Finally, the results of the implementation of the non-vertical structure clearly show the improvement of the navigation accuracy due to the proper estimation of the compensation coefficients.