Attitude Determination System Based on Rotation Mechanism and Beidou Reiceivers

Although inertial navigation based orientation finding is completely autonomous, its real-time performance is limited by the accuracy of gyro, and the cost is very high, which is not suitable for low cost applications. An attitude determination system compose of rotation mechanism and multiple Beidou receivers is proposed, which have the advantages from both inertial system and GNSS system. It is a low cost attitude determination system for low dynamic applications. A rotary encoder is used to provide the rotation speed information and modulated relative rotation angle information, with this information the output from Beidou attitude determination algorithm can be filtered and screened. By discriminate the common mode system error and differential system error, environment dependent effects such as multipath can be minimized, the accuracy of static attitude determination can be improved with data of multiple epochs. A prototype of the system had been built and shown. The data were collected and analyzed. The results show that real-time north finding with high accuracy can be achieved based on the low cost hardware design, the dependence of the heading performance with environment for Beidou system is reduced. A heading performance of 0.04deg was demonstrated.