RTLS in Warehouses: Boosting Efficiency with IoT-Based Systems.
Warehouses, whether they are fulfillment centers or distribution centers, are intricate systems comprised of multiple components that must function harmoniously. Just like any sophisticated structure, warehouse managers encounter several challenges in their quest for effective and uninterrupted operation.
Aside from long-standing issues like asset misplacement, theft, and employee injuries, the current competitive landscape presents significant obstacles centered around enhancing efficiency and operational speed. To thrive in this environment, digitization has become a prerequisite, extending beyond the mere substitution of personnel with robots and autonomous vehicles.
Real-time tracking systems and advanced analytics software play a pivotal role in optimizing warehouse workflows. This article will explore the intricacies involved in choosing the most suitable real-time location system (RTLS), implementing it effectively, and seamlessly integrating it within warehousing environments.
What is RTLS and which warehouse challenges does it address?
Real-time tracking, facilitated by a real-time location system (RTLS), is an autonomous network of interconnected IoT devices that enables the tracking and identification of various objects. This system involves attaching small tags to equipment, vehicles, pallets, or other items, as well as embedding them in employee access cards. These tags transmit real-time or near real-time information to anchors (readers/antennas/receivers) installed throughout the facility. The data is then sent to the cloud for storage and processing.
The transmitted data can include identification information, location, time, asset condition and maintenance status, environmental information (such as temperature and humidity), and more. While real-time tracking cannot entirely replace traditional inventory management approaches based on barcodes and scanning systems due to cost considerations, it is implemented to track high-value assets, inventory, and large shipments. It is also used for monitoring equipment and personnel performance in industrial environments, warehouses, yards, ports/terminals, and for tracking people within facilities for security, navigation, or analytics purposes.
Real-time tracking can address various challenges that warehouse managers face. Let’s discuss some of the common pain points and how an RTLS can help:
Misplaced inventory and equipment: Real-time tracking allows warehouse managers to always know the location of inventory and assets. Tagging pallets and equipment with smart devices enables precise tracking, reducing search time and increasing productivity.
Inefficient picking process: Manual, paper-based picking processes are time-consuming and prone to errors. With an intelligent RTLS, staff members receive clear instructions through devices like wrist computers, AR glasses, or tablets, improving efficiency and accuracy.
Nonoptimal routes: RTLS systems can generate optimal routes for different processes, minimizing travel distances and saving time and fuel. This leads to faster operations and cost savings.
Congested pathways: An RTLS can dynamically reroute workers or reorganize tasks to avoid congestion and ensure smooth workflow, enhancing safety and preventing delays.
Underutilized equipment: RTLS provides visibility into historic asset performance, allowing managers to identify inefficiencies and optimization opportunities. Metrics like distance traveled, time for task completion, and idle time can be monitored to improve resource utilization.
Underutilized storage space: Real-time tracking enables the optimization of storage space usage by analyzing driving patterns and placing frequently accessed items in the most accessible locations. This can lead to increased storage efficiency and capacity.
Asset downtime: Advanced asset tracking systems facilitate predictive maintenance by regularly providing reports on asset health and sending alerts for abnormal functioning. Timely repairs and maintenance minimize downtime and enhance operational efficiency.
Asset theft: Real-time asset tracking devices help reduce the number of missing items and combat theft. Geofencing and automatic alerts can be set up to notify managers if tagged assets leave designated zones.
Security issues: RTLS allows for enhanced security in warehouses by tracking the location of employees. Virtual geofencing and alerts can be employed to ensure safety in restricted or dangerous zones and to prevent accidents.
Lack of visibility into operational processes: By consolidating tracking data in a single system, an RTLS provides a holistic view of asset location, usage, condition, and operational workflows. This centralized access to data enables business intelligence, streamlined reporting, and informed decision-making.
Real-time tracking elevates traditional asset and inventory tracking methods, providing continuous monitoring and enhanced visibility. It relies on various technologies to achieve these capabilities.
Main networking technologies used in RTLSs and how to choose one
There are several tracking technologies that serve as effective foundations for indoor real-time location systems (RTLS): active RFID, Bluetooth Low Energy (BLE), Wi-Fi, and Ultra-Wideband (UWB). These technologies operate on the basis of radio frequency (RF), incorporate batteries for continuous data transmission (although battery life may vary), and can be equipped with sensors to transmit additional information alongside ID and location data. Before delving into the details of each technology, let’s outline the key parameters for comparison:
Read range: The larger the read range of the anchors (readers/antennas), the fewer installations will be required.
Accuracy: Different technologies offer varying positioning accuracy, ranging from sub-meter precision (UWB) to around 15 meters (Wi-Fi). Consider the level of accuracy required for your specific tracking needs. For example, if you need to locate a specific box or pallet in a densely packed room, higher precision technologies may be more suitable.
Pricing: The price range of tags and anchors can vary significantly, and for larger facilities, the number of required devices becomes a decisive factor in cost considerations.
Battery life: In addition to the initial purchase of tracking devices, battery replacement is a consideration, particularly for larger deployments. Low-energy tags with long-lasting batteries and lower power consumption can help reduce costs and effort in the long run.
Now, let’s provide a brief description of the most commonly used wireless networking technologies in indoor RTLS:
Active RFID: Active RFID tags incorporate a battery and transmit signals to RFID readers. They offer relatively long read ranges and can provide good accuracy for indoor tracking. However, they tend to be more expensive compared to other technologies and may require more maintenance due to battery replacements.
Bluetooth Low Energy (BLE): BLE is a wireless communication technology that is widely supported by modern smartphones and devices. It offers moderate read ranges and good accuracy for indoor tracking. BLE tags are generally cost-effective and have longer battery life compared to active RFID.
Wi-Fi: Wi-Fi-based RTLS utilizes Wi-Fi access points as anchors for tracking. It offers a relatively large read range and can provide moderate accuracy for indoor positioning. Wi-Fi tags are cost-effective, and the infrastructure is often already available in many indoor environments. However, the positioning accuracy may not be as high as with some other technologies.
Ultra-Wideband (UWB): UWB technology enables precise indoor tracking with sub-meter accuracy. It offers excellent location precision, making it suitable for tracking individual items or personnel in dense environments. UWB tags typically have good battery life, but the technology may be relatively expensive compared to other options.
These technologies provide the foundation for indoor RTLS and offer varying capabilities in terms of read range, accuracy, pricing, and battery life. Choosing the most suitable technology depends on the specific requirements and constraints of your warehouse environment.
RFID: a classic approach
Passive RFID tags cannot be used for real-time tracking, so we will focus on active RFID tags. They have a read range of up to 100 meters and provide location accuracy of 2-3 meters. Active RFID is popular for indoor asset tracking and container/pallet-level tracking in warehouses. However, RFID technology can be susceptible to interference from RF transmitters like Wi-Fi access points. Additionally, while the tags are relatively inexpensive, the readers can be costly, resulting in higher implementation costs.
Bluetooth: an energy-efficient, highly compatible solution
Bluetooth Low Energy (BLE) has emerged as an industry standard for indoor RTLSs, finding wide application in IoT tracking systems. BLE tags or beacons are designed to be highly energy-efficient, and they offer compatibility with various Bluetooth-enabled devices such as smartphones and computers. The use of BLE technology allows for cost-effective implementation, as specialized readers are more affordable compared to RFID systems.
BLE beacons can transmit data within a range of up to 100 meters (300 feet) and provide positioning accuracy of 1-2 meters (3-7 feet). However, there are some drawbacks to consider. BLE tags may experience latency as they enter a sleep state until they detect the reader signal, which helps conserve power. Signal interference and security vulnerabilities are also potential challenges associated with BLE technology.
Wi-Fi: makes use of existing infrastructure but lacks accuracy
Wi-Fi-based asset tracking systems utilize existing networks to transmit real-time location information. These systems are cost-effective since they leverage the existing infrastructure, but the Wi-Fi tags themselves can be expensive. Wi-Fi networks have the advantage of high data transfer capacity, enabling the quick transmission of large amounts of data. However, Wi-Fi alone provides basic location information, and for more detailed tracking, additional solutions like BLE or UWB may be necessary.
One drawback of Wi-Fi-based tracking is that Wi-Fi tags are typically less power-efficient compared to BLE beacons, resulting in more frequent battery replacements. Additionally, Wi-Fi-based tracking systems generally offer lower precision with an accuracy of around 15 meters (50 feet), unless a dense network of readers is installed. Signal interference and security concerns are also potential issues with Wi-Fi-based tracking.
Therefore, warehouse RTLSs typically do not rely solely on Wi-Fi-enabled tags, but Wi-Fi networks are often utilized in conjunction with other technologies to transmit signals from receivers or readers to the storage and processing platform. In fact, modern enterprise-grade Wi-Fi access points often come equipped with built-in BLE technology.
UWB: high-precision solution that’s least sensitive to RF interference
Ultra-Wideband (UWB) is an emerging radio technology that is gaining popularity for indoor tracking applications. UWB tags are power-efficient, offering a range of up to 100 meters (300 feet) and high data transmission rates of up to 110 Mbit/sec. One notable advantage of UWB is its ability to operate without interfering with other RF transmissions, making it suitable for industrial and logistics environments.
The key strength of UWB lies in its precision, providing location accuracy of up to 10-30 cm. However, this level of precision is achieved when the tracked assets are in clear line of sight of the scanning devices and within the reading range. This requirement makes the implementation of UWB more complex compared to technologies like BLE or RFID. Additionally, UWB tags tend to be more expensive than other types of tags available in the market.
So which RTLS technology do you need?
Indeed, the choice of the RTLS infrastructure depends on various factors such as your existing IT infrastructure, specific requirements, and the physical environment of the facility. It’s common for RTLSs to utilize a combination of different technologies to achieve the best results. For example, a popular approach involves using a blend of BLE/UWB tags for precise tracking and Wi-Fi for data transmission.
Analyzing your existing IT infrastructure is important to determine if you can leverage Wi-Fi networks or if additional network infrastructure needs to be implemented. The desired level of accuracy in positioning results is another crucial consideration, as different technologies offer varying levels of precision. Additionally, evaluating the presence of potential RF interference in the facility is necessary to ensure accurate and reliable RTLS readings.
Ultimately, selecting the right RTLS infrastructure involves carefully assessing your specific needs and conducting a thorough analysis of the available technologies to determine the optimal combination for your warehouse environment.
How does RTLS work: IoT infrastructure
A typical warehouse Real-Time Location System (RTLS) includes four key components: tags, receivers or anchors, storage and processing middleware, and a business application. These components can be obtained as a ready-made solution from a single provider, tailored to meet specific requirements, or purchased individually and integrated into a unified system. Now, let’s discuss each component in detail.
Tags are attached to assets or individuals in a warehouse and transmit ID, location, and time data at regular intervals, which can be customized based on the system settings. Some tags may also include additional features like sensors to track additional readings, LEDs for visual identification, and an alert button for emergency notifications.
There are two types of tags based on their power source: active tags and passive tags. Active tags have batteries, either built-in or replaceable. While the former type is more cost-effective, the entire device needs to be replaced once the battery life is over. On the other hand, the latter type is more expensive initially but allows for battery replacement, eliminating the need for device replacement. Additionally, modern systems often include alerts to notify users when the tag’s battery is running low.
Receivers, also known as readers, are installed within the warehouse to create a connected mesh network that captures signals transmitted by the tags. An analogy to understand their function is that they are similar to satellites in the GPS system. Receivers can be either wired or battery-powered, depending on the vendor and the installation location.
The number of anchors or receivers required depends on the size of the warehousing environment and specific tracking needs. Factors such as the area’s dimensions, line-of-sight availability, and whether 2D or 3D tracking is desired influence the number of anchors needed. For instance, utilizing 4 UWB anchors can cover an area of up to 50×50 meters (164×164 feet) with clear line-of-sight, ensuring accurate tracking.
If you have a complex or challenging environment, it is advisable to consult an RTLS expert to plan the optimal anchor positions. Alternatively, you can use specialized tools like the Pozyx RTLS Planning Suite to devise the RTLS infrastructure yourself.
In addition to capturing tag signals, receivers often serve as gateways that transmit the collected raw data to the cloud or a local server using Wi-Fi or Ethernet connectivity. Installing more receivers enhances tracking accuracy as they synchronize data with each other, complementing the readings from different devices.
Storage and processing middleware
The storage and processing middleware in a warehouse RTLS system consists of a server that stores all the data and includes a location engine to calculate the precise position of tracked objects. This middleware can be hosted in the cloud or on-premises. Cloud platforms are often preferred for their scalability and power, but some companies choose to keep data on their own local servers for security reasons. Edge processing, where reading devices have computing capabilities, is less common.
Servers play a crucial role in converting raw data into actionable information, which is then sent to the business management system for users to utilize. The processing solution is connected to business applications through APIs (Application Programming Interfaces) to facilitate integration and data exchange.
Popular IoT platforms such as IBM Watson, Microsoft Azure, and AWS IoT offer robust capabilities and are commonly used in conjunction with RTLS systems for enhanced data management and analysis.
A business application, whether cloud-based or on-premises, serves as a portal where users can access and interact with the location data in a readable and interactive format. This interface allows real-time tracking on 2D or 3D floor maps, enables asset location lookup by entering their IDs, and provides access to performance dashboards and other relevant data.
The RTLS interface also allows users to configure specific actions based on signals received from the system. For example, authorized equipment or personnel approaching doors can trigger automatic unlocking, or an alert can be sent to a forklift driver in case of potential accident risks. Additionally, the system can run analytics algorithms to extract actionable insights from the data collected.
Implementing an RTLS often involves creating a digital twin, which is a virtual replica of the warehouse facility. This digital twin enables users to experiment with various rearrangement options, run what-if scenarios, and conduct simulation experiments before implementing changes in the actual warehouse. Digital twin technology provides valuable insights and optimization opportunities. If you are interested in this technology, you can explore a detailed overview of digital twins for further information.
Integration between your RTLS and business management software, such as Warehouse Management Systems (WMS), Warehouse Execution Systems (WES), or ERP systems, is crucial for establishing seamless data exchange. This connection enables various benefits, including:
Sending equipment and personnel ID data to the RTLS to create a database of connected tags.
Sending order data to the RTLS to match tasks with staff and equipment, allowing for the creation of optimal routes.
Sending tracking results from the RTLS to the main system for reporting, analytics, and other purposes.
When implementing an RTLS to automate inventory management processes, integration with Inventory Management Software (IMS) becomes essential. This integration facilitates the exchange of information regarding SKU ID details, location, production date, and other relevant data. For example, renowned car manufacturer BMW significantly reduced the number of lost vehicles in storage areas by implementing an RTLS system.
APIs (Application Programming Interfaces) are typically used to establish connectivity between systems. Many RTLS providers offering turnkey services will handle the integration process for you. However, if you need to handle integration yourself, you can engage in-house IT specialists or seek assistance from external connectivity experts. It is advisable to check with your RTLS provider for available open APIs. Some off-the-shelf products come pre-integrated with major WMS/ERP/IMS solutions, simplifying the integration process. However, if you use proprietary software, be prepared for a comprehensive integration project.
When approaching RTLS implementation, here are some recommendations to consider:
Set clear business goals: Define the specific objectives of your RTLS project. Whether it’s minimizing losses, improving operational efficiency, or achieving other targets, understanding your goals will help guide the implementation process.
Calculate expenses: Consider the costs involved in the RTLS project. This includes hardware (tags, anchors), installation, software, integration, maintenance, and staff training. Assessing the expenses upfront will help you plan your budget effectively.
Launch a pilot: Start with a small-scale pilot to test the system’s effectiveness. Install a limited number of tags and anchors in different zones to evaluate accuracy and performance. Test different technologies to determine the most suitable one for your specific needs.
Ensure scalability: Keep scalability in mind when selecting an RTLS system. Consider the system’s capacity to handle a growing number of tags and the scalability of your storage and processing infrastructure, especially if using a local server. Plan for future expansion and consider options like server upgrades or utilizing cloud-based solutions.
Integrate with other systems: Connect your RTLS with other business systems, such as WMS, WES, or ERP, to enhance performance and enable seamless data sharing. Integration allows for a holistic view and streamlined operations.
Conduct staff training: Ensure that your employees are trained in using the RTLS devices and software. Provide access permissions to designated operators and empower managers to make informed decisions based on the additional information provided by the RTLS.
Engage IoT experts: Collaborate with IoT professionals who have expertise in building, connecting, and customizing RTLS systems. Their knowledge and experience will help optimize the implementation process and maximize the value derived from the RTLS.
By following these recommendations, you can approach RTLS implementation in a strategic and effective manner, aligning it with your business objectives and ensuring a successful deployment.