What Is an Indoor Positioning System for Factories? Benefits of Implementation and How to Choose — Explained for Operations Personnel

Table of Contents

• What is an indoor positioning system?

• Benefits of implementing an indoor positioning system in factories

• Main types of indoor positioning technologies and their characteristics

• How to choose an indoor positioning system for factories

• Recommendation for simple surveying using LRTK

• FAQ

What is an indoor positioning system?

An indoor positioning system refers to the technologies and mechanisms for measuring and recording the positions of people and objects in indoor spaces and underground where satellite positioning such as GPS cannot reach. It can be described as an indoor version of GPS and is also called Real Time Location System (RTLS). In buildings such as factories and warehouses, signals from satellites are blocked, so conventional GPS can have errors ranging from several meters to several tens of meters, making it impossible to determine precise locations. Therefore, an indoor positioning system (Indoor Positioning System: IPS) is a solution that enables the acquisition of location information indoors using various methods such as radio waves, sensors, and sound.

In recent years, in factories and logistics warehouses in the manufacturing industry, information about "where people and things are now" has become important in various situations such as equipment and inventory placement, improvement of work flow, and safety management. Even management that traditionally relied on on-site intuition and experience is increasingly being digitized: by visualizing processes with digital technologies, efforts to improve productivity and reduce waste are accelerating. Among these, indoor positioning systems are attracting attention as a core technology for visualizing the movements of people and goods inside factories in real time.

Benefits of Implementing an Indoor Positioning System in Factories

Introducing an indoor positioning system inside a factory brings many benefits to on-site management and operations. Here are some of the main benefits.

• Improved work efficiency: By knowing the current locations of personnel and forklifts, searching and waiting times can be reduced. Required parts, tools, and cargo can be identified immediately, allowing staff to avoid unnecessary movement.

• Optimization of workflow paths: By collecting and analyzing actual movement route data of workers and logistics, locations with unnecessary back-and-forth or congestion can be identified. Based on movement paths, the factory layout can be improved and rearranged for more efficient movement, thereby increasing productivity.

• Enhanced safety management: It can be used for safety measures such as issuing alerts when a worker enters a hazardous area or attaching tags to hard hats and forklifts to detect proximity. Real-time location awareness of people and heavy equipment helps prevent collisions and ensures worker safety.

• Visualization of operational status: The operational status of machinery and personnel can be understood together with location information. For example, you can see at a glance which worker is working where and which forklift is in operation, helping to optimally allocate on-site resources and reduce idle time.

• Streamlining maintenance and inspection tasks: During equipment inspections and maintenance work, inspection targets or locations can be found quickly. If location information is recorded in inspection records, you can accurately document which machine and which part was inspected or repaired, making future inspection planning and information sharing smoother.

These advantages enable indoor positioning systems to deliver significant benefits in both improving factory productivity and enhancing safety. Through automated work recording and streamlining inventory management, they also help address labor shortages and promote on-site DX (digital transformation).

Main Types and Characteristics of Indoor Positioning Technologies

Although the term "indoor positioning system" is used broadly, there are various technical approaches to measuring position. The appropriate approach varies depending on the application and the required accuracy, so it is important to understand the main indoor positioning technologies and their characteristics.

• Wi‑Fi/BLE beacon method: This method places multiple existing Wi‑Fi access points and battery‑powered small transmitters (BLE beacons) throughout a building and estimates position by deriving distance from received signal strength. It can be introduced at relatively low cost without requiring many dedicated devices, but positioning accuracy is fairly coarse—on the order of several meters (several ft) in radius. Reflections and interference from walls or machinery can cause errors, so it is somewhat unsuitable for applications that require high accuracy.

• UWB (ultra‑wideband) method: By using ultra‑wideband radio, this method enables high‑precision positioning to around 10 cm (3.9 in). Multiple dedicated UWB anchors (base stations) are installed to measure distances to tags (mobile units) with high accuracy. It is less prone to interference from other radios and delivers very high accuracy, but hardware costs and the effort required for installation and tuning are higher. It is a strong option for scenarios needing precise location awareness, though the deployment barrier is relatively high.

• RFID method: IC tags (RFID tags) are attached to assets or products, and readers installed in designated areas read those tags to determine whereabouts. Because tags can be read in bulk, this is convenient for managing diverse inventories, and items in visually obscured locations such as inside boxes can be detected as long as radio reaches them. However, effective communication distance is on the order of a few centimeters to a few meters (a few in to a few ft), so the primary use is detecting whether an item passed through a specific gate rather than providing real‑time positions across an entire area. Note also that tag costs accumulate when using many tags.

• Acoustic (ultrasonic) method: Ultrasonic transmitters are placed on ceilings or walls, and distance to receivers carried by people or vehicles is calculated from the time of arrival of sound. Because sound does not pass through walls as readily as radio waves, this characteristic can be used to achieve precise room‑ or floor‑level localization. Some systems even claim three‑dimensional (including height) centimeter‑level accuracy (half‑inch accuracy). However, installation of dedicated infrastructure and periodic calibration are required, so both initial and operating costs tend to be high.

• Camera/LiDAR method: This technique estimates self‑position from surrounding landmarks or reflectors by image analysis of camera footage or by laser scanners (LiDAR). A benefit is that positions can be measured without attaching tags to people or objects, but high‑performance camera equipment and detailed prebuilt indoor maps are sometimes required, so introduction costs tend to be large. In environments that change frequently, such as factory floors, frequent re‑calibration may also be required to maintain accuracy.

• Pedestrian dead reckoning (PDR): This method uses accelerometers, gyroscopes, and other sensors built into smartphones to estimate movement from a person’s walking and calculate the current position relative to a known starting point. It is effective for short periods, but small errors accumulate over time and cause drift, making it unsuitable on its own for long‑duration or long‑distance positioning. It is often used as a supplementary method in combination with other approaches.

As described above, there are various indoor positioning methods, each with their own advantages and disadvantages. For example, if you want to cheaply determine the whereabouts of people or objects with only rough accuracy, the BLE beacon approach is an option, and if you want to determine a forklift's travel position in 10 cm (3.9 in) increments to help prevent collisions, the UWB approach is a candidate. Also, whether the positioning target is a person or an object, and whether it is assumed to be moving or stationary, affects which technology is appropriate. It is important to clarify in your company's factory what you want to track and to what level of accuracy and to consider the method that matches that.

How to Choose an Indoor Positioning System for Factories

When actually introducing an indoor positioning system into a factory, there are several points to consider. From functionality to cost, it is advisable to compare and evaluate the following aspects.

• Purpose and required accuracy: First clarify the intended use. Is it for product inventory location management, or for worker and vehicle safety management? The required accuracy and real-time performance will differ accordingly. Whether you need accuracy of tens of centimeters or less (tens of cm or less, i.e., a few inches or less) to prevent mistakes, or whether rough area-level awareness is sufficient, will narrow down the technologies to choose.

• Coverage and environment: It’s also important to determine how much of the factory grounds will be covered. Consider whether positioning is needed only inside buildings or if coordination with outdoor yards and separate buildings is also required. If you want seamless tracking that includes outdoor areas, choose a system that supports data integration and handoff with outdoor positioning such as GPS. Also note that factory interiors often contain a lot of metal and machinery that create unusual radio conditions, so verify whether the chosen approach operates stably in your specific environment.

• Ease of installation and operation: If installing sensors, antennas, and other equipment requires extensive construction work, you may need to stop production lines or face a large initial burden. Consider whether power and wiring work are required, the effort of battery replacement, and whether it is feasible to have workers carry mobile devices. Prefer systems that minimize on-site burden and are easy to retrofit.

• Cost and cost-effectiveness: Initial installation costs and running costs are major factors. For example, UWB offers high accuracy but device unit prices are high, and costs can balloon in large factories that require many anchors. BLE beacons are inexpensive, but managing a large number of them increases operational costs. Choose a method that fits your company’s scale and budget, and compare return on investment (time and labor savings versus cost). Also consider whether external outsourcing costs (e.g., periodic map creation or system maintenance) are required and evaluate the total cost accordingly.

• System interoperability: Also consider how you will use the acquired location data. Can it integrate with existing production management or inventory management software, and can the data be exported for use with analytics tools? Choosing a platform that supports API integration and customization rather than only a dedicated viewer app will broaden post-deployment use. If you plan to integrate other IoT sensors or outdoor tracking data in the future, select a system with high extensibility.

Consider these points comprehensively and choose the indoor positioning system that best fits your company's needs. For example, if you want to track forklifts from an outdoor yard on the factory premises into the building, you will need to either use GPS outdoors and switch to a different method indoors, or select a hybrid system that can handle both consistently. On the other hand, if you want to pilot on a small scale inside the factory first, you could start with a simple beacon-based approach and then expand it step by step after evaluating its effectiveness.

Guide to Simple Surveying with LRTK

In recent years, a new approach combining smartphones and RTK technology has emerged as a high-precision positioning solution. A representative example of this is a system called "LRTK". LRTK leverages RTK (Real Time Kinematic), a technology for improving satellite positioning accuracy, and enables centimeter-level positioning with smartphones, tablets, and dedicated devices. Traditionally, performing precise position measurements inside factories to within a few centimeters (a few in) required specialized surveying equipment and infrastructure, but with LRTK field personnel can easily take measurements themselves whenever needed.

For example, when changing the layout of a production line, prior surveying is essential to install machines and equipment in the correct positions. With LRTK, you can quickly measure the installation coordinates on the floor yourselves and mark the positions according to the drawings. Because tasks that were previously outsourced to external surveyors can be brought in-house, this leads to significant time and cost savings. LRTK is also useful for recording factory equipment inspections. Inspection photos taken with a smartphone can be automatically tagged with that location's coordinates and orientation and saved to the cloud, so the team can easily share "which location was repaired" and "where to inspect next time." Equipment management that used to rely on handwritten notes on paper drawings can, with LRTK, be preserved as digital map information.

LRTK-based simplified surveying is designed so that on-site staff without surveying expertise can use it. With only a smartphone with the dedicated app installed and a small LRTK device, after performing initial positioning outdoors via satellite reception you can move inside a building and, by simply pressing a button at the point you want to measure, record a high-accuracy position. No complex base station installation or pre-calibration work is required, and you can start measurements on the spot as soon as you decide to. This enables the on-site PDCA cycle (understanding the current situation → planning improvements → verifying effectiveness) to be run quickly. The mobility to re-measure on your own as many times as needed will be a powerful ally for a factory’s continuous Kaizen activities.

Moreover, LRTK is attractive from a cost perspective. Once you have the device and a smartphone, there are no additional costs for each survey. It requires a lower initial investment than deploying expensive fixed equipment or large-scale indoor infrastructure, and it can also reduce surveying fees that were previously outsourced. Economical while delivering both accuracy and efficiency, LRTK can contribute to on-site improvements as a new option. If you face challenges such as "I want to measure but can't" or "I'm troubled by positioning errors," consider a smartphone × LRTK solution.

FAQ

Q. How accurately can an indoor positioning system determine position? A. Accuracy varies depending on the technology used. Systems using BLE beacons or Wi-Fi typically have errors on the order of several meters (several ft), whereas UWB (ultra-wideband) can provide high-precision positioning from the tens of centimeters down to around 10 cm (3.9 in). Systems using ultrasound or specialized cameras also claim high accuracy. However, in many environments real-world performance falls short of theoretical values; in factories with lots of metal or obstacles, reflections and shielding of radio waves can degrade accuracy. It's important to choose the method according to the required accuracy — whether "zone-level awareness is sufficient" or you want to "pinpoint location within a few tens of centimeters (a few in)." Also, methods that apply RTK technology, such as LRTK, can achieve positioning within a few centimeters (a few in) of error indoors when conditions are favorable.

Q. Can indoor positioning and outdoor GPS be combined to seamlessly track movement from outdoors to indoors? A. Yes, it is possible. Outdoors, tracking can be done with GPS or satellite positioning, and there are solutions that automatically switch to an indoor positioning system when you enter a building. For example, Japan’s unique IMES technology transmits signals from indoor transmitters in the same format as GPS signals, an attempt to achieve uninterrupted positioning indoors and outdoors. In many cases, this is handled by integrating indoor position data and outdoor GPS data in software so they can be displayed “seamlessly on a single map.” The important point is to choose a system that supports managing outdoor areas as well if you need that capability. For fleet management of forklifts and work vehicles, deploying an RTLS solution that can track with the same tags or devices from outdoors to indoors will allow smooth centralized management.

Q. Can indoor positioning systems be useful for equipment inspections and maintenance tasks? A. Yes — accurate location information from indoor positioning contributes to streamlining inspections and maintenance. For example, even when inspecting many pieces of equipment in a large factory, if you can know the inspector’s current location and patrol route you can check for "missed inspections." Also, when a fault or anomaly is found, recording and sharing the exact location (which part of the machine or which point in the factory) allows the relevant spot to be identified smoothly during the next inspection or repair. By utilizing LRTK, positioning data can be automatically attached to inspection photos and managed in the cloud, so you can link information such as "which valve was replaced" or "where a crack was" to a map. This improves the accuracy of equipment management and makes it easier to hand over maintenance work that tends to be person-dependent.

Q. Does implementation require high costs or specialized knowledge? A. The implementation costs and the knowledge required for indoor positioning systems vary depending on the approach. For example, with a simple beacon-based system, devices are inexpensive and setup is relatively easy, so you can start without a large investment or advanced IT knowledge. On the other hand, high-precision systems like UWB use dedicated equipment that is expensive, and building the system may require specialized know-how. Recently, more RTLS products have appeared that simplify initial setup by combining with cloud services. Also, solutions that can be completed with a handheld smartphone and a small device, such as LRTK, can be operated by on-site staff after a short training period, so specialized technicians are not necessarily required. It is recommended to start small, try it out, and gradually scale up while monitoring the effects—introduce the system in a way that fits your company without overextending.

Q. Are there any operational points to be aware of after system deployment? A. In terms of operations, attention is needed for regular equipment maintenance and battery replacement. When installing many battery-powered beacons, battery replacements and the replacement of failed devices will occur every few years. Also, when tracking people's movements, it is important to consider privacy and to gain employees' understanding. To maintain system accuracy, calibration (re-adjustment) may be required if antenna or sensor positions shift or the environment changes. On the other hand, solutions like LRTK that perform positioning only when needed have fewer permanently installed devices, so the day-to-day operational burden is relatively small. It is advisable to set the deployment scale within a range your company's resources can manage without strain, and to establish operational workflows.