Almost any application in the area of automatic identification (auto ID) raises fundamental questions about what the appropriate identification technology is for “my application,” but none more than track and trace. Three identification technologies have dominated the market for many years: laser- and image-based identification and RFID.
As the role of identification and tracking systems are increased in usage and overall function, the using of the captured data becomes the real differentiating factor.
The time of Big Data has arrived, and making sure that the way you capture and identify information becomes all the more important.
Using the right technology to identify your products in production and shipping can really help.
As each technology has different strengths, and the fields of application and requirements are extremely varied, none of the technologies is the perfect solution for all auto ID applications. The optimum identification technology for a particular application must always be individually tailored to the technical, economic and current government regulations.
The basic aim is to determine what level of automation needs to be achieved. Does the data need to be saved centrally or is it sent to the cloud, and how securely does the data need to be saved? Is it an open or closed system, and do singulated objects or an accumulation of multiple objects need to be identified? Does a material flow concept according to a particular standard need to be implemented? Is there a need for analysis and further processing of the read results, for example compiling read rate statistics? If there is, does the software need to record the read data at the application, line, plant or company level?
New laws have been passed like the Drug Quality and Security Act that now requires all pharmaceutical firms to add a serial number to all packages within the next four years. Then on top of that, all of these labels need to be upgraded to electronic codes within 10 years. Many of these regulations have been implemented in Europe so they are well underway in their effort to make sure customers are actually getting the genuine product they are paying for.
The type of legislation that is proposed to help control how products are traceable over their entire process from raw material to customer has also been proposed in the food industry. The goal is to easily know where and when a food product may have come in contact with any contamination so the level of risk and ability to contain a foodborne issue becomes more possible. In other words it is the ability to link food through all points of the food distribution, from the farm to the point of sale, and maybe in the future it would become possible to give consumers the ability to see where their food has come from.
ID technologies have different strengths, both in terms of technical specifications and sensitivity to ambient influences. Therefore, an individual decision needs to be made for the application about which technologies are best suited, and offer the user an optimum solution from an economic perspective.
The aim is to select the identification technology with the best price-performance ratio, in which case the benefits are justified by:
- optimum reading performance
- reduced post-processing
- minimum integration, maintenance and repair work
- maximum throughput
- high data availability and transparency
Object-specific information can be saved, updated and called up at any time on the transponder without having to be connected to a central system. This means that objects equipped with RFID transponders can be tracked along the entire logistics or production chain. For example, load carriers, which often circulate in large numbers can be located and tracked, and are therefore guaranteed to find the way back to their own inventory.
The use of RFID is also beneficial when there are harsh ambient conditions, extreme temperatures, or heavy mechanical loads on the objects to be identified. Optical technologies always require a line of sight in order to detect the code and are therefore more sensitive to wear or contamination, so often times there is less maintenance with an RFID based system.
In spite of the fact that purchase prices have dropped greatly, RFID transponders are more expensive than simple labels with 1-D or 2-D codes, which any user can print themselves. Even though RFID tags can be reused, and are also very rugged, the additional costs often only pay off for closed circuits or in the event of cross-company use of the technology. This is where the expansion of RFID could be huge. As the transponders come down in price and the need to track more data continues to increase, RFID offers a great way to increase safety to things like food products so data regarding temperatures and origination site can be updated as products are shipped from factory to warehouse to store.
Due to the physical properties of the radio waves, consideration must be given to liquids and metals in the read field when designing the system: Liquids absorb UHF frequency radiation, and metals disrupt the radio waves, and reflect or absorb them depending on the frequency being used. In many cases, adapted antenna and system designs can balance out these disruptive factors and allow for high read rates even in complex environments.
Laser scanners read 1-D codes, and read them very well, as they can also detect damaged or contaminated codes thanks to sophisticated algorithms. Laser scanners, sometimes called line scanners, direct a laser beam along one line and detect the intensity of the laser light reflected from the light and dark elements of the bar code. Line scanners use the movement of the bar code for error-corrected reading and this can greatly improve the read rates compared to a single scan.
The costs of an individual laser scanner are typically lower than those for a corresponding camera alternative. However, the cost for the omni-directional reading of bar codes is similarly high to that of a camera-based system due to the higher number of individual devices required. The average service lives of industrial laser scanners and cameras are around the same, and therefore have no influence on the consideration of costs. In many systems, the devices have been working reliably without interruption for more than a decade.
Bar code labels are widely used in many fields of application, because they are inexpensive to buy in comparison with RFID tags, and are also standardized around the world. The general advantages of bar codes obviously apply both for laser-based and also for image-based bar code reading devices. The labels can be applied to almost any object.
Two-dimensional codes have greater data density than 1-D bar codes and therefore take up a considerably smaller area for the same amount of data. If 2-D bar codes need to be read, then laser-based code readers can no longer be considered as a solution and an image based system must be used.
Image-based code readers are flexible when it comes time for the customer to select the code type. In addition to 1-D bar codes, the readers use various image processing algorithms to identify both plain text (OCR) and 2-D codes, such as the frequently used data matrix, QR and maxi codes. It is therefore easily possible to switch from 1-D bar codes to 2-D bar codes.
If the orientation of a code in a level is not precisely defined and is variable in the application, then an individual image-based code reader can reliably detect all codes regardless of their orientation. This advantage becomes clear for codes with short bar lengths or other types of misprinted codes. In applications with poor code quality, for example, due to weak contrast or partial destruction, image based code readers achieve reliable read results due to the corrective image processing algorithms. Reading more codes, especially when they are poorly printed or their physical orientation is unknown makes cameras a better fit compared to laser-based code readers.
It’s important to know that there are image-based barcode readers that can help make the transition from laser-based to image-based reading easier. In addition, most image-based bar code readers also have firmware update programs, ensuring that the reader’s firmware can be upgraded with the latest decoding methods and new code types. The idea of future proofing the line allows the user to start transitioning from laser scanners to image-based bar code readers earlier, and allows the flexibility to upgrade in the future without having to replace the readers again and again.
But what to do with all this information, regardless of the technology used to identify the product? Whether you want data on the individual package being produced or the overall throughput of a machine or sorting conveyor in a customer’s warehouse, software to track and compile this data is becoming increasingly important. Important due to the fact that there are many uses for the data, but having the data and effectively storing it so it can be used easily is the goal.
There are systems that log all of the data, and when using an image-based identification system users can also store the images for additional inspections. The user can track side-by-side package conditions, store the dimensions and/or weight of a package and allow the user to recall that data for validation or improvement of the overall system. This can also store information about the temperature of food items at different stages of the distribution system. And as shipping the wrong package is not just an extra cost, it could also cause issues if that package contains food or pharmaceuticals. The risk of allergic reactions by putting the wrong flavor pack in a food or exposing medicine to temperatures that could reduce its efficacy, all point to the fact that using the right type of technology to get the required information into the system is becoming more and more important.
Beyond the improvement of the identification and tracking system the images can be used to inspect the packages for other things when certain conditions are met. For example, if a barcode is not read from a package the image could be used to identify the object by other means such as pattern recognition or by manual inspection of the image so the package can be routed correctly without having to be removed from the system.
As the role of identification and tracking systems are increased in usage and overall function the using of the captured data becomes the real differentiating factor for companies in any industry. The time of Big Data has arrived, and making sure that the way you capture and identify information becomes all the more important, so using the right technology to identify your products in production and shipping can really help. So whether you are using the information to help keep the food supply safe, reduce the proliferation of counterfeit medication, or just make sure your shipment gets to Grandma’s house, the technology used can play a big role in making sure the data is accurate.