Corrections to Fast Complementary Filter for Attitude Estimation Using Low-Cost MARG Sensors
Résumé
In the reference by the authors [1], the quaternion fusion from accelerometer and magnetometer measurements does not have proper mathematical form. The presented equation (43) in [1], actually takes a unit quaternion for attitude representation with a direction vector n followed by a scalar s, which reads [2] q = (n T , s) T (1) However, the filter in [1] ultilizes the quaternion in a scalar-wise form: q = (s, n T) T (2) In this way, the equation (43) in [1] should be revised to q = 1 2 √ ς(ς+|ρ|)(1+b×·r×) (ς + ρ)(1 + b × · r ×) (ς + ρ)(b × × r ×) + σ(b × + r ×) , ρ ≥ 0 σ(1 + b × · r ×) σ(b × × r ×) + (ς − ρ)(b × + r ×) , ρ < 0 (3) Note that neither our implementation nor the experimental evaluation of the method is affected by this mistake. The open-source code is available at: https://github.com/ zarathustr/Fast_Complementary_Filter. REFERENCES [1] J.