Object Tracking and Identification

img How can a computer recognize the presence and identity of objects in its environment? Many diverse technologies are being experimented withsome requiring special markings or transponders and some that do not. Bar codes and RFID (radio frequency ID)are perhaps the oldest and most developed. Bar codes are the familiar Universal Product Code zebra patterns of lines found on many items, such as cans. These codes can flexibly be read in any orientation by bouncing a scanning laser beam off them. Researchers are currently experimenting with two-dimensional markings that will allow the placement of much more information in denser displays and methods of unobtrusively embedding the information in other printed material on the products. RFID requires the placement of a small electronic device on each object that can then be read at a distance without the requirement of visual access. Examples are the security tags placed on store merchandise or library books that activate alarms when someone passes through a portal. Passive tags, which can be produced very inexpensively, use resonant electronics to reply when activated by the inquiring signals. More expensive active tags require battery power, can provide extensive information when queried, and can be dynamically updated. Researchers are working to decrease the cost and increase the range and amount of information contained on the tags. For example, a Micron product used for more complex inventory schemes such as tracking railroad cars and trucks can be read at distances of up to three hundred meters. They even have a system that combines cellular phone and GPS technology and will eventually allow items such as cargo containers to be tracked anywhere in the world. Related technology has been applied to tracking prisoners on house arrest, children at amusement parks (to prevent them from getting lost), taxi cabs (to insure that drivers dont take too lengthy breaks), luxury automobiles (to track them if they are stolen), and military assets (in order to deploy them in battle). Other researchers are attempting to increase the intelligence of video-image processing systems so they can identify objects in natural scenes without special markers or transponders. MITs Physics and Media group is studying the possibility of avoiding circuitry and video altogether by using natural physical features of objects and persons for tracking and identification. For example, the Spin Resonance project is seeking to determine whether the atomic spin patterns of molecules could be sensed and used for identification purposes.