When it comes to logistics, manufacturing, and industrial enterprises, real-time location systems (RTLS) enable unprecedented operational visibility and true Industry 4.0 capabilities. While many are getting by on barcodes and passive RFID tags, the ability to see where and when assets are moving across a facility in near real-time has brought tremendous value to those who have chosen to invest in more advanced systems like RTLS.
RTLS helps solve a range of issues, from improving worker safety to enhancing workflows. By being able to see where all assets are, businesses can identify bottlenecks on assembly lines, optimize routes for vehicles and forklifts, protect equipment from loss and theft and more. By the end of this post, you’ll have a better understanding of what’s required to plan and deploy an effective real-time location system in your facilities.
When looking to invest in RTLS infrastructure, it’s important to know what problem you want to solve to get the right solution. You may want to consider the following:
- Do you have a floor plan, or size of your facility in x,y coordinates?
- How many assets do you want to track?
When approaching a company to set up an RTLS, it’s crucial to have a floor plan or the size of your facility in x,y coordinates to be able to plan out the RTLS. A floorplan is especially useful once it gets turned into a digital map, since a familiar map will be easier to navigate.
Knowing the amount of assets you want to track affects the number of tags you’ll want to buy, and the associated anchors. Scalability is an important factor in determining what location engine is suitable for your RTLS - while a couple hundred assets could work for a classic cluster-based infrastructure solution, assets in the thousands require advanced location engines such as Inpixon’s RTLS software.
Latency and Update Rate
- How often is your digital twin updated?
- What is your preferred position update rate?
Latency is the time between what is happening in the real world and what the digital twin is showing on the system – so it’s important to note how accurate you need this position to be. If needed, delivering location in near real-time (less than 2 seconds on average) is possible, and it requires a cloud-based solution with more sophisticated location engines. The position update rate is how often the location of assets are updated on your system. Therefore, it’s useful to note if you’d prefer daily updates for heavy goods and machinery, every 30 seconds for inventory, every 10 seconds if you’re tracking pallets, or every second for theft prevention.
Ranging & Accuracy
- How accurate do you want the positioning to be?
- Do you only want indoor tracking or a combination of indoor and outdoor tracking?
- How important is reliability?
Knowing how accurate you want the positioning of your assets to be is essential too, since this affects what radio-frequency (RF) technology your RTLS uses. For example, accuracy of 1-2 meters works best with Chirp Spread Spectrum (CSS), while high accuracy of less than 40 centimeters works best with Ultra-Wideband (UWB). If your RTLS requires long ranging and indoor & outdoor tracking, chirp is the best solution, ranging up to 1000 meters.
Long ranging with chirp can help to optimize infrastructure costs since it reduces anchors needed and supports highly scalable deployments. Chirp is also the best option for reliability if proactive situation awareness is required, in harsh industrial environments for example. If the priority is finding assets in re-active use cases or in consumer environments, UWB is more suitable. A mixed infrastructure of UWB and chirp is also possible and can be considered in infrastructure planning.
Multipurpose Use Cases
- Do you want location tracking, ranging, or both?
- What are you tracking?
- Do you need to comply with any regulations?
Being aware of location tracking versus ranging is important, since that affects what infrastructure is involved. Location tracking requires tags, anchors and location engine, while ranging only requires tags. They also have different use cases - while location tracking involves tracking the direct position of assets, ranging is usually used in safety-related collision avoidance scenarios with lower latency requirements as tags can communicate with each other. In addition, ranging allows for individual door access, traffic control systems, on-demand ventilation and the creation of geofenced safety zones.
While some companies only require an RTLS for one use case, others may want to track assets and improve worker safety concurrently. If there’s a need for a combination of multiple applications, Inpixon RTLS offers a 3-in-1 solution that saves customers time to market and reduces the amount of technologies required to a minimum. Additionally, if you’re looking to deploy your RTLS globally, you might run into regulatory compliance issues. While UWB has outstanding accuracy in its positioning, it has some regional limitations - so the Chirp 2.4GHz ISM Band is a great option to perform global installations without a license.
The Different Components of RTLS Infrastructure
RTLS Anchors are fixed readers in your facility that detect RF signals from moving tags and devices within their communication range. The most accurate mechanism for location tracking using anchors is Time-Difference-of-Arrival (TDoA). In this system, anchors work by time stamping the received signals, also called blinks, and sending the information back to the location engine. The location data the anchors transmit can be used to make important decisions about how operations are flowing, as the coordinates can be visualized on a digitized map.
The type of anchor you need depends on what position accuracy and range you require. For high-precision location tracking, a UWB anchor would be the best match. For example, the Inpixon nanoANQ UWB provides accuracy to +/- 40 centimeters. On the other hand, for long range tracking at meter accuracy, a chirp anchor such as the Inpixon nanoANQ Chirp functions better as it ranges up to 1000 meters. Companies can also choose to build their own anchors, and buy components such as the Inpixon nanoANQ PCB, Inpixon Swarm modules or the Inpixon nanoLOC transceiver to integrate with their RTLS to enable tracking.
Some Inpixon anchors support customers with two channels for increased reliability in receiving signals and to improve the coverage of tunnel or corridor directions. The biggest priority for anchors is being able to receive signals from tags from as many locations as possible, which is why awareness of possible interferences is crucial. Anything that could block the signal should be avoided where possible, such as metal, concrete or metalized windows. However, there are strategies to mitigate these effects, such as enhanced anchor placement. The number of required anchors can be optimized by increasing their position, height, or orientation, as well moving antenna cables to dedicated places for an increased coverage.
The type of antenna used needs to be taken into consideration as well: these include directional or omnidirectional antennas. Whilst omnidirectional antennas (monopole) or dipole antenna (stub) are typically used in 2D or 3D scenarios, directional antennas are used in 1D scenarios like in underground mining, tunnels or building corridors. Usually, directional antennas are available with circular polarization which mitigates the negative effects of RF signal reflections and have higher signal gain.
RTLS tags are small wireless devices with sensors that can be attached to assets, people, vehicles and even livestock to determine their location. They work by sending location data at continuous intervals (blinks) which are received by anchors. Once the data is sent by the anchor to the location engine and visualized on a map, each asset will be represented on the map because of its attachment to a tag.
Whether companies are looking to gain control and visibility over their assets, determine the best routes for their forklifts or make sure they can evacuate personnel in case of an emergency, tags are the main way everything can be accounted for. Depending on the use case, tags can look different. Vehicle and asset tracking tags, are usually attached to the side or on top; for employees they’re attached to their helmet, safety vest, lanyard or belt; and for livestock they’re attached to their ears.
Ideally, tags are in line of sight to 3-4 anchors at a time to guarantee the best possible location performance. For this reason, the ideal position of a tag is the highest possible point of the asset, to prevent the signal from being blocked. For example, with personnel tracking tags, the ideal position of a tag is the helmet as it allows as many anchors as possible to receive the signal without blocking the signal by the body itself. The more anchors are able to receive the signal, the better chance there is to get an accurate location.
A location engine is the software that receives the location data from the anchors that were sent by tags and calculates the position of the tag. For location tracking using TDoA, it calculates the tag’s x,y,z coordinates by analyzing the time stamps that the anchors receive from the tags and creates an estimate of the distance between the tags and anchors through multilateration. The tag’s position is then sent to the Indoor Positioning System (IPS) or RTLS.
This location data is useful in a variety of use cases, such as the mass tracking of assets, process monitoring, enhancing operations, and evacuation or mustering in emergency situations. The Inpixon nanoLES location engine works for both precise tracking (UWB) and long ranging (chirp), and because it supports the industrial RESTful API interface, it allows you to integrate real-time location tracking into external IoT platforms.
Ethernet cables are crucial to keeping the RTLS connected. Ethernet is the most common type of Local Area Network (LAN) and works to connect all devices on the same network. It’s connected by cable, and it’s used for its high speed and reliability. Security is also a top use case, since no one can interfere through the network via cable, unlike wireless networks.
In an RTLS, ethernet cables are connected to anchors, switches in the company’s IT infrastructure and their location engine. This ensures that all information is transmitted from anchors to location engines, so that the data can reach the RTLS. During location tracking, when the RTLS is using TDoA, clock synchronization of the anchors works through Ethernet cables, ensuring that the position of tags is measured correctly.
Ideally a power over ethernet (PoE) based infrastructure (including a PoE switch and PoE anchors) allows you to reduce the amount of DC connections needed to power the anchors, since the PoE conveniently combines power and network with the same network cable. All anchors from Inpixon support this feature.
Important Use Cases for RTLS Infrastructure
RTLS infrastructure can be leveraged to improve worker safety in a variety of scenarios. For example, in industrial environments such as mining, it’s important to have reliable RF technology. Chirp is the most suitable option to enable autonomous collision avoidance and mine tracking in this situation, thanks to its very strong protection against interference. To add, the right mapping software would be needed in cases of evacuation and mustering. On a digitized map companies will be able to see and account for all their personnel and can even create safety and prohibited zones.
Industrial Asset Tracking
Tracking of expensive machines, engines, tools and goods in harsh environments requires a highly reliable technology that works indoors and outdoors. Chirp is a proven RF asset tracking technology that can reduce the infrastructure cost (since it requires fewer anchors) and delivers meter-level accuracy.
Smart warehouses require high accuracy UWB for the precise tracking of indoor goods. This could also be leveraged with chirp (for outdoor tracking) to close the gap between asset tracking from truck to warehouse. An end-to-end product software suite for transportation and in & outbound shipments is also recommended.
In smart factories, RTLS connects the various areas of production using IoT. The type of RF technology needed in a smart factory depends on the facility and type of assets, as is the case with smart warehousing. An end-to-end product software suite for paperless factories, assembly-line monitoring and yard management completes the RTLS as an optimal solution.