October 2003

Automatic Tracking of Assets
A Brief Overview of RFID Technology

P. Benjamin

Asset Tracking

Asset tracking refers to the ability to identify, locate, sort, count and detect an infinite variety of items, including people, live stock, vehicles and objects in an industrial, commercial or retail setting. It is the process of monitoring and tracking physical assets through tagging mechanisms, indicating their current location, past locations and movements throughout a facility at all times thus making it a valuable tool of Asset Management.
Asset tracking systems uses what is popularly known as RFID (Radio Frequency Identification) technology which first appeared in tracking and access applications during the 1980s. Since then RFID, which creates a dynamic link between people, objects and processes, has established itself as a primary player in the future of asset data collection, identification and analysis systems.

Versatile Applications

The uses for RFID technology are limitless. Potential applications for RFID may be identified in virtually every sector of industry, commerce and services where there exists a need for data to be collected with an ability to track moving objects even at high speeds.

Principal areas of application for RFID that can be currently identified include:

• Transportation and logistics

• Manufacturing and Processing

• Security

Some of the more prominent specific applications include:

• Electronic article surveillance - clothing retail outlets being typical.

• Protection of valuable equipment against theft, unauthorised removal or asset management.

• Controlled access to vehicles, parking areas and fuel facilities - depot facilities being typical.

• Highway toll management-Automated toll collection for roads and bridges

• Controlled access of personnel to secure or hazardous locations.

• Time and attendance - to replace conventional "slot card" time keeping systems.

• Animal tagging / Animal husbandry - for identification in support of individualised feeding and breeding programmes.

• Automatic identification of tools in numerically controlled machines - to facilitate condition monitoring of tools, for use in managing tool usage and minimising waste due to excessive machine tool wear.

• Identification of product variants and process control in flexible manufacture systems.

• Sport time recording

• Electronic monitoring of offenders at home

• Vehicle anti-theft systems and car immobilizer

• Waste management

• Postal tracking

• Airline baggage reconciliation

• Tracking library books.

More flexible and easier to use than bar coding or other forms of data collection, RFID is a multi-purpose technology. While this presentation will discuss the capabilities of RFID and site some specific examples, it may be kept in mind that the full potential of RFID technology has only just started to be realized -- perhaps some of the greatest applications and unique solutions based on RFID have yet to come to market.

What Is RFID?

RFID is a highly reliable way to electronically control, detect and track a variety of items using FM transmission methods. The object of any RFID system is to carry data in suitable transponders, generally known as tags, and to retrieve data, by machine-readable means, at a suitable time and place to satisfy particular application needs. Data within a tag may provide identification for an item in manufacture, goods in transit, a location, the identity of a vehicle, an animal or individual. By including additional data the prospect is provided for supporting applications through item-specific information or instructions immediately available on reading the tag. The tag, or transponder, affixed to or embedded into virtually any object (including livestock) individually identifies the object using a unique, factory-programmed, unalterable code.

RFID tags come in two types: active and passive. Active transponders include a battery while passive transponders obtain their energy from a radio frequency signal sent from the interrogation unit or reader. The battery-free transponders' identification capability last the life of the product or system in which the transponder is located.
Since RFID does not require line-of-sight between the transponder and the reader, these systems overcome the limitations of other automatic identification approaches, such as bar coding. This means that RFID systems work effectively in hostile environments where excessive dirt, dust, moisture and/or poor visibility would normally hamper rapid identification. One of the most outstanding benefits of RFID is its ability to read through these environments at remarkable speeds -- responding in less than 100 milliseconds in most cases.
Furthermore, RFID is completely automatic and transparent, eliminating the need to scan an object manually or activate a magnetic stripe, reader, or other contact ID technology.

RFID System Components

To understand and appreciate the capabilities of RFID systems it is necessary to consider their constituent parts. 

A RFID system comprises a number of components including a range of transponders, handheld or stationary readers, data input units, and system software. The transponders, or ID tags, are the backbone of the technology and come in all shapes, sizes and read ranges.
Read only transponders, which can be read at a distance of up to one meter, contain a unique factory-programmed ID code, consisting of bits (from 32 to 64) or digits. Read-write transponders consist of bits of code that can be programmed by the user to revise and update data. This capability allows for a custom coding and numbering system so that data can be easily integrated with other computerized information and automation systems. Data collected from either type of transponder can be sent directly to a host computer through standard interfaces, or stored in a portable reader until uploaded to a computer for data processing.

Technical Choices

Low vs. High-Frequency

The need for either the low-frequency or high-frequency tag is dependent on the application. A low-frequency device typically provides slower data transfer and must work at closer distances to an object. Relative speed of the tag moving on a production line past an interrogation unit is approximately 32 Km an hour. On the other hand, high-frequency devices can work at distances up to 250 feet and at relative speeds greater than 240 Km per hour.
High-frequency passive systems are typically in the UHF range -- i.e. from 500 MHz and above, but usually in the 900 MHz band to 2.5 GHz. These systems are particularly well suited to the automotive, trucking and container shipping industries because they can read distances in excess of 15 feet and can communicate large amounts of information at very high speeds.
This high-frequency system works when a reader sends a signal to the transponder or ID tag via an antenna. The transponder's electronics return the ID code via a modulated signal being continuously reflected off the transponder's antenna, giving an impressively quick read.
Low frequency systems on the other hand, are more suitable for tracking, monitoring or controlling the work flow of objects used for manufacturing, production, and processes. In a low frequency passive system (typically 30 kHz to 500 kHz), a reader sends a signal to the tag, charging the transponder and allowing it to return a signal carrying the unique identification code stored within it. Since most low-frequency systems are passive, the transponder can be built into devices or parts during the manufacturing process, and continue to electronically identify an object for its lifetime.

In addition, low-frequency systems allow for accurate transmission through most nonmetallic materials - making them an excellent solution when tracking almost any type of objects or containers.

RFID in Security Field
With Canadian Mounted Police

It is reported that the Canadian Mounted Police have implemented an RFID solution to help keep track of 250 police cruisers and 800 officers. The nature of the profession requires that this federal police force maintain an extremely high level security system to monitor vehicles and personnel and prevent unauthorized access to the facility. With transponders located on the cruisers, it is essential that the technology not only read through dirt, grime and snow-- often the result of inclement Canadian weather -- but also process access and security information in a precise and prompt manner.

Airport / Port Security

At the recently held Airport Security Expo in Las Vegas, Applied Digital Solutions and its VeriChip Corporation featured its VeriPass and VeriTag. These new applications will allow airport and port security personnel to link a VeriChip subscriber to his or her luggage-both during check-in and on the airplane-flight manifest logs and airline or law enforcement software databases. 

VeriChip can enhance airport security, airline security, cruise ship security, intelligent transportation and port congestion management

VeriChip is a miniaturized radio frequency identification device that can be used in a variety of security applications. About the size of a grain of rice, each VeriChip product contains a unique verification number and will be available in several formats, some of which will be insertable under the skin, which, by the way, is in the works to track a patient's medical status.
It is also mooted that since VeriChip's personal verification technology can't be lost, stolen, tampered with, misplaced or counterfeited, its secure personal verification system can ultimately be incorporated into airport security initiatives on a nation-wide basis.

Access Control & Beyond

Another manufacturer, Texas Instruments, is making a huge splash in the industry and has deployed more than 180 million tags (TI-RFid) worldwide in a range of RFID applications. TI-RFid's line of cards and badges provide factory-programmed ID, which cannot be duplicated, ensuring that no two cards or people are misidentified. With more than 2000 bits of data, the cards hold 50 times more data than traditional (125 kHz) solutions. The data is written and stored directly on the card, independent from a host system, allowing employees to carry vital information such as authorization codes, certification or emergency medical histories. TI's cards also provide the capacity for stronger encrypted security and the data capacity to use the ID cards beyond just facility access for other solutions, such as biometrics and wireless financial transactions.

Other Common Applications of RFID
Highway Toll Collection

RFID systems are currently being integrated into Automatic Vehicle Identification (AVI) applications for the automatic collection of tolls. With a transponder placed on the dashboard, RFID technology is being used to deduct tolls from vehicles traveling at highway speeds. In this case the long-range high-frequency transponders are capable of transmitting at speeds of 160 Km per hour and at 300 kilobits per second.

Rail Transportation

Since the goods wagons of the railways are always on the move, real time tracking of the wagons is a complex problem. RFID systems are uniquely suited for use in this rigorous environment. With field programmable tags attached to the under carriage, antennae installed between or adjacent to the tracks and readers typically located within 40 to 100 feet in a wayside hut along with other control and communication equipment, automatic identification of each wagon, even while they are on the move, by type, serial number and any other programmed particulars is possible thus permitting improved fleet utilization which is the primary objective. 

Road Transportation

Commercial truckers are using RFID systems to monitor access and egress from terminal facilities. Combined with weigh-in-motion scales, the same systems can be used for transaction recording at refuse dumps, recycling plants, mines and similar operations, or for credit transactions at truck stops or service depots. 

Shipping

RFID works well for a shipping company that needs to maintain information on all goods and shipments from receipt to departure. A major Asian port recently began using RFID to track multi-ton cargo containers on a daily basis, to manage the loading and unloading of numerous ships and countless truck loading areas and to ensure the accurate transfer of goods between the vessels and storage areas. Thousands of transponders embedded into the ground act as an electronic grid throughout the port. As cranes move about the yard lifting cargo on and off ships, trucks and vessels, RFID readers mounted on the lifting arms interrogate each transponder they pass, matching the transponder's code with the location in the yard. The entire system supplies personnel with real-time information on the location and destination of each container and its freight.

Industrial

RFID versatility and data capture make it ideal for truly integrated facilities such as manufacturing plants that need to link data from the delivery of raw materials to final warehousing and distribution. 
Future Potential of RFID
RFID is a technology that helps us discover completely new and novel solutions to existing problems which also generate some new opportunities along the way. RFID solutions in one area is bound to create many new opportunities in others, enhancing the value of the technology and creating new cost benefits that far exceed original estimates. Attaching an R.FID transponder to an automobile chassis at the assembly plant will certainly assist with the automatic manufacturing, streamlining production and improving parts and inventory control. But the same transponder can be equally valuable in identifying the care for warranty and repairs, theft protection or even by serving as an electronic link to future automated highway systems.
Clearly, RFID offers us tremendous opportunities by contributing to savings of time and manpower, reductions in waste, and creating new heights of cost efficiency, productivity and total quality.
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