WP5-19 ACO

Robust communication for an improved Indoor Positioning System

ID	WP4-19
Contributor	ACORDE
Levels	Function
Require	Indoor Positioning System anchor and tag platforms WP3-15_1
Provide	Robust and enriched communication among beacons and becons/drone
Input	Specific messages among UWB devices.
Output	robust and enriched communication
C4D building block	(see WP3-15_1)
TRL	4
Parent Building block	WP3-15_1
Contact	fernando.herrera at acorde.com

Description

In WP5 of COMP4DRONES, ACORDE worked to enable a robust and enriched communication among anchors and among tag and anchors on its Indoor Positioning Solution WP3-15_1.

Robust communication among anchors and between the tag and its surrounding anchors is essential. Specially in the latter case, for the tag to compute its position. The obtention of the ranges relies on a Two-Way Ranging (TWR) protocol where up to four short messages need to be exchanged. This causes a traffic that, depending on the medium access control (MAC) protocol, might lead to collisions and loss of messages. For the TWR protocol this is an especially bad scenario, because sending retrials do not only adds latencies, but it also complicates much range estimation up to the point of disabling it.

Enriched communication means two things in this context. First, enriched communication stands for the ability to augment the information exchanged among anchors and between tag and anchors. This enriched information enables the higher layers, namely the location algorithms to make better estimates. The second meaning of enriched communication refers to the extension of the capabilities at the user-level interface (integrator API), to have access to such an enriched information. This was indeed a requirement from the integrator company in the UC2-Demo2, which desired to make data fusion of the ACORDE UWB-IPS data with other source of data (LIDAR).

How and Benefits

For robust communication, ACORDE has developed and integrated a MAC scheme for robust communication at the tag ranging phase. This is a novel MAC scheme which exploits the described usage scenario, for ensuring robustness and optimizing the amount of anchor ranges that can be safely handled (i.e., deterministically and without collision) at the tag-anchor ranging phase.

ACORDE enables enriched communication by introducing a specific message extension at the lower implementation levels (MAC, ranging) to enable the exchange of data on error related information. This type of enriched communication enables better robustness against error

ACORDE also enables enriched communicaton by introducing on the specific message extension' additional data beyond locations and ranges (the minimum information for enabling trilateration). This additional information can be exploited by the positioning algorithms (developed in WP4) for improving the accuracy of the position estimation.

Finally, ACORDE also tackled the enriched user-level API by proposing a Mavlink extension which enables the provision of information like ranges, so that drone integrator activity is facilitated.

Figure below sketches these main actions for robust and enriched communication of the ACORDE IPS solution tackled in the WP5 package of the project.

ACORDE enabled robust and enriched communication across serveral implementation layers of its Indoor Positioning Solution

Evaluation

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Set-up used for assessment of communication robustness in outdoor experiments

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