Abstract: [Purposes] To aim at the calibration of the inertial measurement unit (IMU)mounting angles for vehicle-mounted systems. [Methods] This paper proposes a rapid estimation method for vehicular IMU mounting angles.The method leverages the kinematic characteristics of the vehicle during straight-line motion,enabling the direct analytical calculation of the mounting angles using the velocity in the IMU body frame,without requiring prior trajectory computation. [Findings] Experimental results demonstrate that,for a tactical-grade IMU,the accuracies for the heading and pitch mounting angles are 0.039° and 0.019°,respectively. [Conclusions] Theoretical analysis and simulation experiments demonstrate that the method supports online,real-time,fast,and accurate estimation of the mounting angles,making it suitable for vehicular navigation systems that require frequent IMU mounting angle calibration or employ real-time kinematic constraints.

Key words: mounting angle estimation, inertial measurement unit, real-time estimation