OD/SINS adaptive integrated navigation method with non-holonomic constraints

Abstract

In the ground vehicle integrated navigation GNSS/OD/SINS, the global navigation satellite system (GNSS) signal is susceptible to environmental interference or even interruption. The non-holonomic constraint (NHC) is applied to the odometer (OD)/strap-down inertial navigation system (SINS) combination, which can effectively suppress the error divergence of the integrated navigation system during the GNSS signal interruption. Usually, NHC's noise setting is based on a fixed empirical value. However, the trajectory of the vehicle is complex and changeable during actual movement, and its motion state cannot fully satisfy the NHC premises and assumptions. The noise given by experience cannot accurately reflect the actual vehicle motion. Therefore, this paper analyzes the relationship between NHC noise and vehicle motion state, and constructs a NHC noise adaptive method based on vehicle motion state. Validation of the real-world experiments of the selected scene shows that the result of the noise-adaptive NHC/OD/SINS combined navigation is compared with the fixed-noise NHC/OD/SINS combination, when the GNSS signal is interrupted for 110 s and the vehicle turns continuously, the maximum horizontal position error is reduced by 68.4%; when the GNSS signal is interrupted for 74 seconds and the vehicle is traveling in a straight line, the maximum horizontal position error is reduced by 87.3%; the error divergence of the integrated navigation system during the GNSS interruption can be better suppressed.