nunoguedelha
commented
8 years ago The issue narrowed down to be in the measurements from one accelerometer : the 11B6 in the right upper leg. Indeed, all data read from that sensor are invalid (-1) in the input data file (data.log). This looks to be an isolated issue: I've captured a new data set since, and all readings seem ok.
I'll keep paying attention in the next data set captures. I'm closing the issue.
measured2estimatedGravNormIssue.pdf @naveenoid , I did some unit testing on the cost function and found a discrepancy between the measurements and the predictions. I plotted the norm of both quantities for a given data subset of 100 samples. I'm expecting to have a constant value around 9.8 and 10 m.s-2 with very small oscillation (<1/10). I get a flat line from the prediction (positive proper acceleration) but a 10m.s-2 oscillation in the measurements (refer to attached figure). I didn't have time to look thourouly, but it looks like 1 measurement is missing / is null for every timestamp. I suspect an index issue. It should be easy to debug tomorrow.