Smoothing
Due the the integrativ and recursive nature of the customary ZUPT-aided INS, the covariances will grow throughout each ZUPT-less period and collaps as soon as ZUPTs are applied. This will give rise to large corrections giving ‘discontinuites’ in the estimated trajectories. However, for many applications, such as motion analysis and visualization, some lag can be tolerated and therefore smoothing can be applied to remove the discountinuities. We have initialized some work on smoothing for ZUPT-aided INS. Hopefully we will have some articles on the subject soon, but in the meanwhile we will make the current status of the code available here.
Just to try it and see the results, you can download the file, unzip it and run main.m in Matlab.
Acknowledgement: The work on smoothing has primarily been carried out by our master-thesis student David Simón Colomar.