UWB RTLS for Indoor Tracking

RTLS is a real-time indoor location service that locates and monitors any person or asset within a defined area covered by a RF network. RTLS systems utilize a combination of hardware and software to create an indoor tracking network.

RTLS network uses transceivers (also known as RTLS anchors) placed throughout the area to transmit and receive the signals to and from the active RTLS tags. RTLS tags are primarily made up of a small antenna, motion sensors, a MCU and a battery. Most batteries on RTLS tags can last for months or years. The tags are attached to asset or person whose location needs to be monitored and tracked.

The tags transmit a few times once in a minute or hour or day, depending on how often you want the location data update.

The signals captured by the anchors are directed to Senstornet location engine software that runs on cloud for location determination. All the anchors have their dedicated Wi-Fi cloud connectivity to save the infrastructure cost. The location calculated by engine is sent back to dashboard UI application running on smartphone or desktop where their positioned on the facility map layout.

 

Locus

Locus is Senstornet’s UWB RF based RTLS product for indoor tracking application. Locus anchors and tags are the hardware used within a given area to locate the x,y position of an asset or a person. The calculated position of an asset or a person is then positioned using the facility layout map in AMMC (Asset Monitoring and Management Console), a dashboard UI web-application that runs on desktop. Locus can track an asset or a person to the accuracy of 25cm and gives a battery life up to 3 years.

UWB is a RF communication technology for short-range use for the fast and stable transmission of data, both indoors and outdoors. It is based on the combination of very short pulses moving at the speed of light.
Predominantly, ToF (Time-of-Flight) method is used to calculate the distance between the tag and the anchor. The anchors send UWB signals, the tags return them. The distance is calculated based on the time it takes the pulses between sending and receiving.ToF has the highest precision and positional stability.

Other widely used topologies are :-

   ✔ TDOA: Time Difference of Arrival

   ✔ TWR: Two-Way Ranging


TDOA

The tag sends out a “blink” signal, each anchor that receives the signal timestamps its arrival. The timestamps from multiple anchors are then used to determine the tag’s location based on the differences in the time.

TWR

Determine the time it takes for UWB RF signals to pass back and forth between the Anchor and the Tag (ToF) and then multiply that time by the speed of light.
Locus uses TWR method to precisely locate the tag with in the RF zone.

 

 

UNIQUE FEATURES AND BENEFITS OF LOCUS

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Architecture

The Locusproduct follows an IoT architecture. The tags are devices that are attached to the asset or worn by person, while the anchors are placed in reference or fixed place to receive the signals from the tags. The distance information collected by each anchor is then transmitted to cloud for further data processing. After passing few layers of filteration algorithms, the data containing the distance information is processed and transmitted back to the dashboard UI in the API form for position representation on the facility map, thanks to the « Maiva Location Engine »algorithm

LOCUS ANCHOR AND TAG PRODUCT SPECIFICATION

✔ Powered by Qorvo’s DWM3000 UWB✔ Range of anchor: 38 to 40 metres diagonal distance
✔ Maximum area covered under one zone: 28×56 metres with total no. of 6 anchors
✔ Minimum area covered under one zone: 28×28 metres with total no. of 4 anchors
✔ Distance accuracy: 25cm
✔ Remote software upgrade available for AMMC UI application
✔ On-site firmware upgrade for Anchors/Tags

Hardware

The anchor can be powered externally by a 5V DC input using an adapter or a micro-USB port.
The tags are available in 3 different variants. The main difference being the battery life and the form factor.

hardware_locus