Integrated Sensor Radio Frequency Identification (ISRFID)

The integrated sensor radio frequency identification system (ISFRID) is a performance centered design tool developed for logistics workers to alert in-storage and in-transit exceedences of conditions like temperature, pressure, and humidity that can be corrected to prevent damage to high-value assets. As a by-product, inventory and transportation system managers gain valuable information that leads to total asset visibility and enables improved decisions for better utilization of critical support assets.

Expensive assets like jet engines, helicopter transmissions, etc. are not shipped by companies like UPS and FEDEX and are typically stored in air-tight, pressurized canisters to protect them from environmental elements such as humidity and extreme temperature fluctuations. The same canisters also serve as the shipping containers when items are transported from one location to another. For costly assets in storage and in transit, the airtight pressurized seals of the shipping containers are critical to protect the assets. Inventory logistics specialists today utilize visual systems such as color-coding through desiccant ports and pressure relief valves to monitor internal conditions of the canister. This labor intense, low skill task is frequently not performed properly if at all and damaged assets are usually the result of seals that allow in humidity-laden air. The ISRFID system provides temperature, humidity and pressure exceedence alerts to the integrated logistics specialists to focus their maintenance efforts on canisters that have exceedences thereby reducing workload and improving performance. Material requirements planners and logisticians for the maintenance repair, and overhaul activities of high-value assets must currently rely on labor-intense procedures and paper based tracking systems to manage the storage and in-transit visibility of these mission critical end items. As a result, assets are frequently lost in-transit, and once stored, often cannot be located. The Government Accounting Office estimates that eleven percent of the Department of Defense

The current method of monitoring for humidity intrusion requires an individual to manually inspect each container on a periodic basis. This is a slow, tedious process that many times is overlooked by the responsible group due to other job priorities and in some respects the volume of containers that must be surveyed.

Additional problems arise from tracking the movement of these assets and their respective shipping containers. Each location must log the shipment and acceptance of a container. This information is input into a central tracking system that monitors the movement of containers. Unfortunately, it is very common for shipping documents to get misplaced or for shipments to arrive at a particular location and go unnoticed for long periods of time.

Through a project sponsored by the Naval Inventory Control Point (NAVICP) of the United States Navy, the Logistics and Maintenance Applied Research Center (LandMARC) at Georgia Tech has developed an integrated hardware and software system to monitor and track high-value assets providing inventory logistic specialists with performance support tools to focus their maintenance efforts on the containers where the seals have been compromised and conditions exist that could lead to the damage of the assets. The system is called Integrated Sensor Radio Frequency Identification or ISRFID.

Solution: The ISRFID system provides several performance advantages in areas of process automation and simplification, integration into existing applications to improve performance, and input devices that enhance the human performance. The general objective is to provide intelligent and proactive assets that will automatically provide status on:

The hardware designed for the ISRFID is a new technology that did not previously exist. It is a programmable tag that consists of a microprocessor, RF transceiver, and various environmental sensors all placed on a small circuit board (see Figure 2) that are packaged together with a long-life battery. The entire unit is securely mounted inside of the storage/shipping container for the purpose of monitoring the environmental conditions that the asset is exposed to and storing important asset and container information that can later be retransmitted.

The tag can transmit and receive messages through RF communications as well as store data, via the microprocessor, in non-volatile memory for recall at a later time. For example, the tag might receive an RF message to store the serial number of an asset inside a container from a handheld device. Since the container is in a sealed unit, an interrogation message could prompt the tag to retransmit that serial number at a later time. This feature proves highly valuable if the paperwork is ever lost during storage or shipping. Typical information that can be stored includes asset ID, asset serial number, container ID, container serial number, and various other fields such as a tracking number to identify its destination. This also improves the efficiency of the user's time in locating particular assets since most containers are erroneously marked.

The tag also monitors the conditions inside the container continuously, and transmits real-time data on a periodic basis or instantaneously through remote interrogation. Remote interrogation can occur through a local PC or handheld device. The normal monitoring operation consists of setting high and low thresholds for various sensors and having the tag automatically transmit an exceedence notification when a particular sensor detects a value outside of the set threshold.

RF transmissions and receptions are monitored and controlled through several software interfaces. Through use of an off-the-shelf handheld device like an IPAQ or Palm Pilot, the tag can be programmed and interrogated using the ISRFID handheld software. The software is compatible with both the Windows CE platform and the Palm OS platform. The only requirement for communications is a specially designed RF transceiver, also built by GTRI, which attaches to the built-in serial port of the handheld device.

Features of the handheld interface include a broadcast command that is issued to all tags in close proximity (less than 100 feet). Each tag will respond to the handheld with their unique serial number and a list will be displayed to the user. The user can then select an individual tag from all available tags for the purpose of programming or interrogating that tag.

Programming the tag can include storing important serial numbers, setting sensor thresholds, and clearing any exceedences that have been detected. Interrogating the tag involves recalling any stored data as well as reporting the current values of the environmental sensors. If an exceedence is present, the value will be highlighted in red text to provide a visual warning to the user.

A second software interface component in the system is the Remote Monitoring Station or RMS. Whereas the handheld is intended for one-to-one programming and interrogation, the RMS monitors an entire local zone of tagged containers. The RMS software is installed on a local PC and has the ability to interrogate and monitor several hundred tags over period of time. Depending on the size of a military base or storage yard, it is possible that multiple RMS locations would exist in large areas.

The RMS has all of the features resident in the handheld interface, but adds several important features that enable the local zone to be monitored with little to no human intervention. The RMS will periodically transmit broadcast messages to determine if any new containers have been introduced to the local zone. This same process would also determine if containers have been removed from the local zone. This list of local containers is maintained by the RMS for several important reasons. First, each tag is automatically interrogated every few hours to determine its current condition. All readings that are gathered are displayed on the screen and any exceedences are highlighted in red. Second, the list is made available to the users so they can quickly determine which containers are in the area. The RMS software aggregates the data into logical groupings to make it quick and easy to obtain an overall status of the local zone.

The most important feature of the RMS is that it serves to gather data for a 24 hour period and automatically transmit this data to the third piece of ISRFID software, the Central Monitoring Station (CMS). The RMS is configured to automatically establish a dial-up connection to the Internet and FTP the RMS data files to the CMS for storage in a database.

The CMS interface is a web-based interface that resides in one central location. It consists of a website, an Oracle database, and a small Java application. The website is built on JSP technology which allows us to create dynamic content and achieve platform independence. From the website, users have access to sensor readings from anywhere in the world. Not only can users view environmental conditions for a specific asset container, but also quickly determine where a specific asset or container is located.

The homepage of the CMS presents the user with quick container and asset search options. There is also a large map showing all the different RMS locations that are being monitored. By clicking on the map location, the user is taken to a screen showing current readings for that location. Interface features of the website include the ability to sort any of the data columns, filter data by date, location, serial number and/or exceedence, and view data by asset, sensor, or containers only.

The most obvious advantage of ISRFID is the automated monitoring of assets and containers. The existing methods of checking environmental conditions inside a container were often unreliable and not consistently practiced. ISRFID eliminates these problems by allowing automatic monitoring of the containers through the tags placed inside the containers. The RMS software automatically detects the presence of a tag and immediately begins to monitor its sensor readings. Users now have the ability to sit down at one computer and monitor hundreds of containers at once. This results in significant amounts of time and money saved.

The second advantage to ISRFID is the ability to store data on the tag itself. Currently, the asset and container paperwork is stored in a small box on the outside of the container. If this paperwork is ever lost of damaged, the only way to determine the contents of the container is by breaking the seal of the container and removing the lid or cover. This is a time consuming and costly process due to the size and conditions of the container. With ISRFID, a person can simply interrogate the tag inside for important information via the handheld or RMS interfaces.

The third advantage of ISRFID is the asset and container tracking information provided by the system. The RMS interface automatically detects the movement of tags and therefore it tracks the movement of the containers. When an RMS location updates the CMS database with a new tag location, you immediately know where a container has moved. This process takes place independent of when and where a normal shipping clerk decides to update their own records. This tracking ability significantly reduces the time it takes to locate containers or assets that might be missing.

Before ISRFID, it was required that an individual physically visit each container and check the environmental storage conditions of the container. To check humidity, for instance, a little blue sticker was placed inside the container and was visible through a small view port. The inspector had to locate the sticker and visually evaluate its color. If the sticker turned pink, that meant that humidity was too high. A blue color meant that humidity levels were acceptable.

Manually checking hundreds or thousands of containers took enormous amounts of time and labor. In most cases, the containers simply were not checked for long periods of time. This often resulted in damaged assets that had to be repaired or replaced at considerable cost to the military. Other problems include forgetting to place the humidity sticker inside the container or having the sticker fall out of place.

In terms of tracking the assets, the Navy currently has a large database for keeping track of valuable assets such as engines. The system is called the Aircraft Engine Management System or AEMS. This database relies on the shipping and receiving locations to manually input the location updates of assets. Most of the time, this process does not take place in a timely and reliable fashion. With the Oracle database that the CMS maintains, AEMS administrators have the ability to verify asset locations based on information supplied by various RMS updates.

There are two groups of users impacted by ISRFID. The first group is the inventory logistic specialists. The majority of those in the first group have a high school equivalent education and are provided minimal information. They possess critical knowledge for remediation of condition exceedences. ISRFID will enable the inventory logistic specialists to perform the tasks for which they are most knowledgeable by concentrating their efforts to situations that require remediation.

The second user impacted by the ISRFID is the inventory planner who relies on outdated information to predict quantity requirements at inventory nodes based on experience versus information. With ISRFID the inventory planner will be able to use his/her experience and knowledge combined with information on asset location and status to optimize the total inventory schedule repair and support actions with greater accuracy as well as reduce the total assets required to manage the pipeline. In effect, the inventory planner will become a command and control specialist armed with information that enables him/her to anticipate and provide the right assets at the right place at the right time.

* Currently the Navy loses a number of engines/modules while in transit over a given year. This year NAVAIR (Naval Aviation Systems) had proposed to survey up to 30 engines. With this proactive system we can avoid these surveys thus saving an estimated $5.6 M per year- the cost of finding an estimated 14 engines per year that would otherwise be surveyed.