An innovative high-precision SINS/CNS deep integrated navigation scheme for the Mars rover

The Mars rovers are the key to Mars exploration missions. In order to achieve long-time autonomous roving and perform science operations, Mars rovers need to have the capability of high-precision autonomous navigation. According to the characteristics of the Martian environment, an innovative scheme of strap-down inertial navigation system/celestial navigation system (SINS/CNS) deep integration for the Mars rover and its implementation are proposed. First, the large field of view (FOV) star sensor is utilized to assist the attitude matrix of SINS by continually observing and correcting the misalignment angles and gyro drifts. Thus, the high-precision mathematic reference is obtained. Then, the star sensor makes use of the reference provided by SINS to obtain the local position vector. The rover's position and attitude can be determined by CNS. On the basis of the mathematics reference, the innovative scheme of SINS/CNS deep integration which takes full advantage of the navigation information of each subsystem is presented. Moreover, the errors of inertial measurement unit (IMU) and the navigation parameters in SINS are estimated and corrected. And the deep integration of SINS/CNS is performed. Compared to the optimal integration mode, this scheme improves navigation accuracy. In the end, the simulation results indicate that this scheme is steady and reliable.