Sub-metre accuracy claimed for indoor Bluetooth positioning kits

Update: December 9, 2023

Sub-metre accuracy claimed for indoor Bluetooth positioning kits

“Recognising the growing demand for more accurate indoor positioning solutions,” according to u-blox, “Bluetooth SIG released Bluetooth Direction Finding, offering a major improvement over previous receiver signal strength-based [‘RSSI’] solutions.”

It works with mobile tags and ‘anchor points’, which are fixed detectors. Antenna arrays on the detectors allow angle-of-arrival (AoA) to be measured. AoAs from a constellation of detectors allows location to be calculated.

The kits are:

  • XPLR-AOA-1 with the u-blox C211 antenna board, C209 tag and software.
    For detecting whether a person or an object is approaching a door, avoiding collisions between moving objects and directing a camera at a moving tag
  • XPLR-AOA-2 with four C211 antenna boards, four C209 tags and software.
    Indoor position proof-of-concept.

Both kits use u-blox’ Nina-B4 Bluetooth 5.1 Low Energy module built around Nordic Semiconductor’s nRF52833 system-on-chip.

Running on the SoC’s embedded MCU, u-blox’ ‘u-connectLocate’ software calculates the angles of incoming signals. XPLR-AOA-2 includes triangulation software to calculate tag positions.

The company has teamed up with Traxmate to combine XPLR-AOA-2 with Traxmate’s cloud-based enterprise asset tracking platform, to make it “easier to set up the tracking environment, create buildings, upload floor plans and specify the placement of the anchor points”, said u-blox. “Users can track the location of assets in real-time via the web or a dedicated smartphone app.”

Applications are foreseen in access control, collision detection, smart appliances and asset tracking.

“We see huge potential for Bluetooth to deliver a solution for locating people and things indoors,” said u-blox product manager Erik Carlberg. “We look forward to engaging with early adopters of the technology and fine-tuning our solution.”