The tracking of various entities in a commercial enterprise, whether it is capital equipment, work-in-progress product or finally inventory that is being consumed and replaced all fall under the title of “asset tracking”.
Numerous technologies have been developed to help solve asset tracking problems. Having a sense of the types of problems and the options to consider among solution technologies is necessary if a robust, cost-effective solution is to be found.
There are four broad classes of asset management / asset tracking problems:
- “Point, low density” asset identification and tracking. These are generally problems such as tracking parts on an assembly line as they enter or leave a work area, grocery or retail store inventory/SKU tracking, typically at points of sale etc. The need is for a relatively small amount of information, a cheap, easy to generate and use identifier and a relatively short range.
- “Point, high density” asset information and tracking. These are asset tracking technologies that enable higher densities of information storage to be associated with the tracked objects.
- “Local” asset tracking. These kinds of problems require asset tracking at a longer distance, up to 3-10 meters typically. They often involve bulk item tracking such as shipping crate contents.
- “Wide area” asset information and tracking. These cases involve the tracking of assets over wider geographical areas. They typically require the ability to track moving assets, usually within a few meters of accuracy, but also in special cases to the order of centimeter preciseness.
Point, Low Density = Barcode
Point, low density asset identification and tracking problems are actually very common in the industry. The basic technology to help solve these problems, the barcode, has been around since the 60’s. They are easy to produce, both as pre-printed tags or time of use tags, and are generally reliable. These are linear data encodings and require straight line scanning by a nearby reader. Because of their maturity they are broadly accepted.
There are tens of barcodes that have been standardized across the world. Similarly, there are a range of industry specific encoding for the information stored in these barcodes that have been accepted as international standards. A typical example is the UPC code or the GS1 encoding standard. Linear bar-codes however do not carry large amounts of data and are susceptible to even minor distortion. They typically carry less than 20 characters of information. They are read-only trackers.
Point, High Density = QR Code
Point, high density tracking technologies were originally invented by the Japanese automotive industry. In contrast to bar codes, these technologies use 2 dimensional encodings of asset data in what are called quick response (QR) codes. They have several advantages including fast readability (they can be scanned in multiple directions and contain specific orientation markers to enhance readability). They also hold considerably more data than linear barcodes, typically a few thousand characters of information.
Two other advantages of QR codes is that they are error correcting codes with the ability to manage to recover up to around 30% of damaged bits, and because of their compatibility with simple imaging devices such as a camera are nearly universally supported by any mobile device. This has made them the chosen way to provide linking information such as encoded URLs that allow the mobile device to access high quality representations of information about the asset. Like barcodes, these are also read only trackers.
Local = RFID
Local asset tracking technologies are distinguished by their ability to sense assets at extended distances. Because they are based on RF technology, detection does not require close proximity or line of sight as with the two previous types of technology we have described. There are different classes of RF based tags based on the frequency that is used. Low frequency tags have short read ranges, approximately 10 cm and slower read speeds but good insensitivity to interference. High frequency tags have longer read ranges, typically up to a meter and can read multiple tags at once. They have several limitations, including increased sensitivity to interference.
Ultra High Frequency tags have extremely high read ranges, and easily handle multiple tag reads at high rates. They are the cheapest RF tags to manufacture. UHF Tags are highly standardized by both GS1 and EPC thus providing excellent support for interoperability and integration into higher level workflow applications such as SAP. All RF technology-based asset solutions have the advantage of supporting writable tags that enable much more precise and much richer workflows.
Wide Area = GPS
Wide Area asset tracking technologies are often thought of as “GPS” based tracking technologies where a GPS receiver is used by an asset to localize itself and to then either transmit its location to a satellite receiver or to log locations for later retrieval. While this is the most common form of wide area tracking technology, there are two other broad approaches to wide area tracking that are currently becoming popular.
The first is the use of low power, long range wireless technologies such as LORA or NB-IoT, that enable devices to communicate directly back to a receiver or aggregation hub over ranges that are typically of the order of 20 km. The second is to use bluetooth low energy (BLE) along with GPS to overcome the poor performance of GPS within indoor locations. Asset tags are BLE enabled and respond to beacons, typically at strategic locations that enable the tags to be localized. Popular examples are Apple Tags and Tile trackers. These tags tend to be expensive and depend on the presence of an underlying communication infrastructure to work.
Hopefully this problem and solution characterization framework will help you find a robust and cost-effective solution for your problem!
IoTReady provides industrial-grade API-ready scanners for barcodes, QR codes and UHF RFID tags. Pre-built support for SAP, AWS, Azure and custom HTTP(S)/Websockets APIs allow easy and secure integration, validation and deployment with local or cloud-based ERPs. Secure OTA (over-the-air) updates ensure robust, long-term operational stability.