Position, Velocity, and Attitude Estimation Based on MARG and Position Measurements Under Unknown External Acceleration

Estimation of position, velocity, and attitude of a rigid body is crucial for various applications. Many of these rely on position and Magnetic, Angular Rate, and Gravity (MARG) sensors, which consist of a gyroscope measuring angular velocity, a magnetometer measuring the magnetic field, and an accelerometer measuring gravity along with an unknown external acceleration. This external acceleration also appears in the kinematic equation of velocity. In this letter, a position, velocity, and SO(3) attitude estimation algorithm is designed differently by considering the problem of external acceleration as an unknown input affecting both the dynamic model and measurements. The effectiveness of the algorithm is validated through Monte Carlo simulations.