Though the local drift is very low, it is not suitable for large-scale mapping since accumulative error is inevitable.
However, since the accumulative error is inevitable in the calculation process, we cannot construct globally consistent map for large-scale environments.
In practice, there is an accumulative error. The experimental results show that the growth of translational errors is about to be less than 2% of distance traveled and rotational errors less than 0.3[degrees] per meter.
Although the measured speed or estimated heading angle is smoother and more continuous than the results from GNSS, it never means that DR positioning results are better as it is a relative positioning method and unavoidably exits accumulative error while GNSS is absolute positioning method.
Trajectory doesn't exit accumulative error and has a high accuracy of long-term.
Therefore, our 2-hop localization scheme has no accumulative error
. Without the influence of accumulative error
, the unknown nodes' localization accuracy will be improved.
This includes the accumulative error
of the ring gage, the probe, and the recorder.
We can see although the networks' averages are the same, the accumulative error
of the cooperative estimation of the second network is less than the first one.
Owing to the fact that the estimation position purely by SINS method has accumulative error after a long time, the SINS system needs to benefit from the aid of other positioning systems.
WSN positioning is a kind of distributed positioning method which has no accumulative error after a long-term racking.
However, the SINS method is known for its accumulative error and the WSN method may have large positioning errors.
I reasoned that, since our successive governments invariably function on a "trial and error" basis; we would be better offer with the current mediocre cabinet (that might learn from its accumulative errors
) than with a new one that will start the trial and error process from scratch.