According to the real time of the lever arm error compensation in strapdown inertial navigation system, a novel
lever arm effect error compensation method is proposed in this paper. The length of lever arm is used as the state variable,
and the lever arm effect error is compensated by estimating the lever arm length in real time. The cause of lever arm effect is
analyzed, derived and analyzed theoretically, and demonstrated via simulation. The simulation results show that, compared
with the conventional error compensation method, the presented scheme not only can estimate the lever arm length precisely,
but also can improve the accuracy of alignment effectively.