UWB Active-Passive Two-Way Ranging Protocol Data Captured in an Industrial Environment

The text file anchor_coordinates.txt contains the anchor coordinates (in meters) used in the tests in the form: <ANCHOR HEX ID>, <X-COORDINATE>, <Y-COORDINATE>, <Z-COORDINATE>

The text file stationary_truecoordinates.txt contains the true coordinates (in meters) for each stationary test point in the form of: <FILENAME>, <X-COORDINATE>, <Y-COORDINATE>, <Z-COORDINATE>

The text file movement_truecoordinates.txt contains the true coordinates (in meters) for the critical points of the movement tests in the form of: <CRITICAL POINT NUMBER>, <X-COORDINATE>, <Y-COORDINATE>, <Z-COORDINATE>

Text files movement.txt and stationaryX.txt (X is the number on the stationary point) contain the AP-TWR ranging data (in centimeters) from which the AP-TWR measurement matrices are composed. The files contain 2 kinds of messages RR_L and LR_E, where the former contains the active SS-TWR range estimates and the internal clock counter of the tag (in milliseconds) and the latter consists of the passive range estimates (and the active SS-TWR range estimates of that specific anchor should be repeated after the <SELF> field). The <SEQUENCE NUMBER> (running from 0 to 255 is a cyclical number for the ranging sequence) and <TAG HEX ID> fields tie together the corresponding RR_L and LR_E messages. The movement tests also contain COORD_E messages, but these are not relevant from the standpoint of the tests - they are coordinates calculated by the Eliko UWB RTLS, and should be ignored.

Considering that the number of active anchors is m, the structure of RR_L messages is the following (irrelevant information, such as tag/anchor informational flags, etc. are not explained and left as <BLANK>):

<$PEKIO>, <MESSAGE TYPE: RR_L>, <SEQUENCE NUMBER>, <TAG HEX ID>, m times (<ANCHOR HEX ID>, <DISTANCE VALUE>), <TAG TIME COUNTER IN ms>, m times (<BLANK>), <BLANK>

The same considerations are are taken for the LR_E messages, where the structure is (Note that <PASSIVE ESTIMATE CALCULATION> fields containing the asterisk *, denote that during this slot in the raniging sequence, the anchor was actively ranging):

<$PEKIO>, <MESSAGE TYPE: LR_E>, <SEQUENCE NUMBER>, <BLANK>, <PASSIVE ANCHOR HEX ID>, m times (<LISTENED ACTIVE ANCHOR HEX ID>, <PASSIVE RANGE ESTIMATE>, <PASSIVE ESTIMATE CALCULATION>), <SELF FIELD DESIGNATOR>, <ACTIVE SS-TWR RANGE ESTIMATE>, <NRI FIELD DESIGNATOR>, <NUMBER OF INTERCEPTED ACTIVE RANGINGS>, 8 times (<BLANK>)

Based on the RR_L and LR_E messages, the AP-TWR measurement matrices for each ranging sequence is formed, the sampling times for the Extended Kalman Filter are extracted from the data of RR_L messages.