A new type of rotating modulation SINS

With the gradual pefection of the inertial instruments, which is insensitivity to gravity acceleration, e. g. optical gyroscope, a kind of rotating modulation technology has developed from electrostatic gyroscope. Consequently, it is possible to build high precision inertia navigation systems using this method based on the low cost optical gyroscopes. Based on the analysis of principle and limitation of the single-axis and two-axis revolving modulating technology, this paper proposes a kind of four-gyroscope strapdown inertial navigation system (SINS) with double single-axis rotating modulation scheme. The influences to inertial navigation system caused by the non-alignment error of evolving axis, non-alignment error of measured axis, constant drift error and scale factor error are investigated. Compared with non-rotation scheme, single-axis rotation scheme and two-axis rotation scheme, the double single-axis with four gyroscopes is more accurate than single-axis rotation scheme. Meanwhile, it obtains similar accuracy in comparison with two-axis rotation scheme, but its complexity has been greatly reduced.