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Rotation modulation technology of inertial navigation system brings navigation performance increasement without any new requirement on inertial sensors. However, device errors still make significant influence on navigation precision. Traditional temperature model identification methods cost plenty of time which reduce production efficiency. Therefore, it is necessary to study an effective solution decreasing temperature resulted errors for engineering application. The paper proposes a fast-self-calibration method for temperature errors. A continuous rotation scheme is designed to excite 21 errors inside of 10 minutes. Kalman Filter algorithm is applied to estimate 21 errors taking velocity errors and position errors as measurements. In order to identify temperature model, the rotation scheme is repeated ten times to estimate error parameters under different temperature. Due to the fast rotation scheme, temperature rising rate can be higher than traditional methods and calibration time is shortened. Finally, the method is verified by simulations and experiments.

Ring laser gyro (RLG) can work in mechanically dithered mode or rate-biased mode according to the working state of the inertial navigation system (INS). It can change from one mode to the other by receiving outer instructions. To evaluate the performance of RLG in rate-biased mode, an inertial measurement unit (IMU) based on RLG is installed on a dual-axis turntable, the turntable offers a constant angular velocity to the RLGs, in that way RLG can work in the rate-biased mode. A calibration method is proposed to calibrate the scale factor error, misalignments and constant bias of RLG in rate-biased mode, experiment results show that the differences of scale factor of the three gyros in two modes are 9 ppm, 7 ppm and 3.5 ppm, the constant biases of the three RLGs in rate-biased mode are also different from that in mechanically dithered mode with the difference of 0.017°/h, 0.011°/h and 0.020°/h, the input axis misalignment angle of RLGs in different modes also changed. What is more, a calculation method of angle random walk (ARW) of RLG in rate-biased mode is also presented. Experimental results show that the ARW of the RLG in rate-biased mode is about one third of that in mechanically dithered.

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Rotary optical encoder is an important component in rotational inertial navigation system. It is used to form a closed loop motor control system and calculate the system attitude. The system performance will be affected by the encoders’ error. Besides the installation errors, the working temperature variants will also lead to encoders’ error. Therefore, the paper proposes a method to calibrate and compensate temperature resulted errors for rotary optical encoders. Firstly, an independent testing mechanism with position limitation and rotatable platform is designed and produced to verify the temperature influences on encoders. Then, the temperature error of rotary optical encoder used in rotational inertial navigation system is calculated by the gyroscope whose sensitive axis is parallel to the same motor axis. The method is verified by a self-researched single axis rotational inertial navigation system. According to the experimental results, the attitude accuracy is increased more than 36.7% compared with traditional method.