Three-azimuth rotation/one position calibration and piecewise linear interpolation compensation for FOG IMU in full temperatures

For decreasing measurement error of fiber optic gyroscope(FOG) inertial measurement unit(IMU) in severe environmental conditions, a new technique was proposed by using a three-azimuth rotation /one position calibration and piecewise linear interpolation(PLI) compensation method in full temperatures. An accurate error model of FOG IMU was established. The three-azimuth rotation rate/one position calibration experiment was implemented in a series of constant temperature. A piecewise linear interpolation arithmetic was used to compensate the bias and the scale factor temperature error of gyroscopes and accelerometers. The measurement precision of FOG IMU is improved by a factor of five. The vehicle experiment results show that the inertial navigation errors is less than 1° in 4200 s after using the proposed method.