Research On Error Coefficient Calibration Method Of GINS Carried By Missile

An new integrated calibration scheme of GINS carried by missile is proposed in this paper which is based on the researching object that calibration algorithm which calculate the three-axis stable platform error coefficient. This work is accomplished in two steps. The structure feature of three-axis stable platform is investigated at first, then the gyroscope error coefficient calibration algorithm based on main&&sub gimbal inertial navigation system(GINS)’s gimbal error angle and the calibration algorithm of accelerometer based on the gravity norm observation are formulated to propose the new integrated calibration scheme.Firstly, it’s practical that the proposed three-axis stable platform error coefficient calibration scheme integrated with the carrier’s movement scheme to the predetermined area, which not only shorten the arranged time before launching but also avoid carrier’s movement affecting the calibration accuracy.Secondly, the kinematic equations of main&&sub inertial platform gimbal angle error are formulated by analyzing the structure, component and movement transferring feature of inertial platform system. With sub INS gyroscope error coefficient expanded as system states and main&&sub inertial platform gimbal angle error as observation the system kinematic equation include six states which are three main&&sub inertial platform gimbal angle errors and three sub INS gyroscope zero order term errors. It’s the system kinematic equation that accurately estimate the three sub INS gyroscope zero order term errors. Simulation results indicate that the observability of the proposed calibration scheme which is based on main&&sub inertial platform gimbal angle error is intense, and gyro base installation error angle of main inertial platform has little impact on sub inertial platform system calibration accuracy which is hardly affected by main INS gyro error coefficients. The results also show that the more intense vessel movement, the less relative calibration error and ocean wave has nothing to do with the sub inertial platform calibration accuracy.Finally, the calibration algorithm of accelerometer is based on some variation of the output-model of accelerometer and the observation of the norm of the local gravity vector. The simulation experiment shows that, when platform has no turntable error, the accuracy of constant factor reaches 510?0g while the accuracy of proportion factor within 10 ppm.The scheme is not sensitive to the turntable error of platform, the performance of spin has no influence on the calibration that weakens the requirements of control precision of the platform stabilization loop. The accuracy of azimuth is independent of calibration which has also been proved by the simulation experiment.