MAGUS

Enhance accuracy in a GNSS-denied space using Pozyx ultra-wideband (UWB) as an aiding source

No GNSS? No problem
· With the OxTS’ Pozyx 2GAD (to Generic Aiding Data) solution, you can enhance the data accuracy you achieve in your multi-storey car parks, tunnels, underpasses and other GNSS-denied spaces.
· The solution enables real-time position updates, provided by a Pozyx ultra-wideband system, to be fused with your OxTS INS inertial measurements for improved navigation performance in the absence of GNSS signals.

Enhanced accuracy
· of position, orientation and dynamics data in the absence of GNSS aiding

GNSS-Pozyx transitions
· enable routes into and out of GNSS-denied areas

Different inputs, same outputs
· delivered at high data rate (100 Hz or 250 Hz), with low latency, as with GNSS aiding

Approved robot integration
· compatible with industry-standard products including AB Dynamics Launchpad 80 and GST

Compatibility with RT-Range
· enables relative measurements to up to four targets

Uses OxTS’ 2GAD technology
· to fuse Pozyx data with inertial measurements in the trusted OxTS navigation engine

HORIBA MIRA case study:

OxTS were presented with the challenge of finding an indoor localisation solution that could output accurate position data in the absence of GNSS signals, such as GPS, in the HORIBA MIRA car park infrastructure.

The solution would be used for the sole purpose of developing, validating and verifying AVP, Park Assist and other related systems.

The agreed upon solution uses ultra-wideband (UWB), from OxTS technology partner, Pozyx, as an aiding source for the RT3000 v3. UWB was the ideal candidate owing to accuracy comparable with camera and LiDAR at a cost comparable with Wi-Fi and Bluetooth Low Energy (BLE).

Key Components

There are four main components that enable the Pozyx 2GAD solution: Pozyx Anchors, Pozyx Tags, Pozyx Gateway and an OxTS inertial navigation system (INS) with Pozyx 2GAD option.

Pozyx Anchors

Anchors are a series of modules dispersed around the testing area.

Each anchor has a fixed, known position having been (semi-)permanently installed around the test area with their coordinates accurately surveyed.

A minimum of four anchors are needed to trilaterate position.

Pozyx Tag

Situated on the exterior of the vehicle.

Pozyx tags continuously transmit short pulses to the anchors.

The relative position of the tags to anchors, and the time-of-flight for each pulse, changes as the vehicle travels it’s route.

The time-of-flight measurements to each anchor are used to calculate the position of the tags within the space.

Pozyx Gateway

Combines and processes information from each of the Pozyx Anchors and Tags to deliver a real-time position upodates.

These real-time updates are then passed to the OxTS inertial navigation system to aid the navigation solution.

RT3000 v3 with Pozyx 2GAD option

Situated within the vehicle.

Receives aiding data from the Pozyx Gateway via OxTS’ proprietary Generic Aiding interface which facilitates the use of different sensors (such as Pozyx UWB) within the navigation solution.

The OxTS INS fuses Pozyx position updates with inertial measurements to produce a single position solution with greater accuracy than either system could achieve in isolation.

The INS output is unchanged from that produced with GNSS-aiding; delivered at a high data rate (100 Hz or 250 Hz), with low latency, ensuring existing integrations with AB Dynamics robots work as usual.

Compatible OxTS INS devices including RT3000 v3 and RT1003 v2.

Technical Information

Performance (1) (2) (3) (4) (5) (6)
Relative position accuracy (CEP)	3.5cm
Relative velocity accuracy (RMS)	0.3km/h
Relative roll/pitch accuracy (1σ)	0.04º
Relative heading accuracy (1σ)	0.3º

1. All UWB system performance is dependant on local environmental factors such as geometry and reflections. System performance will vary depending on the local environment it is being used in.

2. Accuracy of the OxTS INS is in reference to the Pozyx UWB system. Offset and bias introduced by the Pozyx UWB system cannot be measured by the INS.

3. Results were recorded in a Pozyx UWB environment area that had the positing algorithm optimised by Pozyx, with an estimated anchor density of 10 anchors per 500 m2.

4. Valid with RT3000 v3.

5. Valid for flat surface.

6. Varies with dynamics.