3.3.1 Absolute Pose Error (APE) as Localization Metric
The EVO tool (https://github.com/MichaelGrupp/evo) is employed to assess
the localization precision, with the Absolute Pose Error (APE) serving
as the evaluation index. APE measures the deviation in pose estimation,
including both rotational and translational errors, relative to a ground
truth reference. The Absolute Pose Error (APE) at time \(i\) can be
calculated using the Euclidean distance, as follows:
\(\text{APE}_{i}=\parallel SE(3)_{\text{est},i}-SE(3)_{\text{gt},i}\parallel\) (11)
where \(SE(3)_{\text{est},i}\) denotes the estimated pose at time \(i\)and \(SE(3)_{\text{gt},i}\) represents the ground truth pose at the same
time.
In this study, APE represents a combination of rotational and
translational errors, calculated as a dimensionless second-order norm of
pose discrepancies. Fig. 5 presents the comparative APE results, and
rounded-off quantitative comparisons are provided in Table 3.