High-Accuracy SINS/LDV Integration for Long-Distance Land Navigation

Since the conventional strapdown inertial navigation system (SINS)- and odometer (OD)-integrated navigation has certain limitations, such as suffering from scale factor variation and being affected by wheel slipping and skidding, we present a high-accuracy integrated navigation system that uses both the SINS and laser Doppler velocimeter (LDV) for land vehicles to overcome these problems. We took the lever-arm residual and boresight errors into consideration and formed a complete 21-state Kalman filter to accomplish integrated navigation and precise sensor-to-sensor calibration. The observability analysis of the SINS/LDV system provides valuable insights into the conditions under which the states can be estimated. In addition, the summed measurement model and sequential Kalman filter calculation are deduced to make full use of the nonholonomic constraints (NHC) and LDV measurements. Finally, a long-distance experiment (230 km) with a navigation-grade IMU demonstrated that positioning accuracies of better than 0.02% of the distance travelled can be achieved in both the horizontal and vertical directions.