Abstract:
A positioning terminal for generating position information of an object being transported includes a radio frequency identification (RFID) module for storing status information of the object relative to at least two predefined locations, and a communication module for sending position information of the object to a control center. A controller reads the status information from the RFID module at predefined intervals, and controls activation of the communication module based on the status information.

Description:
FIELD OF INVENTION 
   The present invention relates to a technology for realizing and improving tracking ability of moving objects in the field of shipping and transportation. 
   BACKGROUND OF THE INVENTION 
   Application and utilization of Radio Frequency Identification (RFID) in the fields of physical distribution, load distribution, and product manufacturing are known. An RFID device is also called an IC tag or a radio frequency tag, and generally includes a small antenna and a very small IC module which is provided with a memory. Data can be read from or written to the memory using an RFID reader/writer. 
   In the field of transportation involving the use of aircrafts, there is a need to track and record the freight transportation route. One way to satisfy such need is the use of Global Positioning System (GPS). Specifically, a GPS terminal is attached to a freight including a GPS module and a communication module for transmitting and receiving the position information obtained by the GPS module to and from a control center. 
   However, origination of signals from a GPS terminal from within an aircraft is legally prohibited. Therefore, it is required that the function of the GPS terminal be validated only during land transportation. As such, the GPS module and the communication module of the GPS terminal are manually invalidated before the start of transportation by an aircraft. These modules are manually validated again when the land transportation starts again. 
   For solving a part of this problem, a technology is known in which sensors are used to inactivate the GPS terminal when the terminal is determined to be within an aircraft. However, this technology is not provided with any means for detecting the transfer of the GPS terminal to the outside of the aircraft. 
   Moreover, even if it is possible to use various systems including the GPS terminal to detect whether the terminal is within an aircraft, it is desirable to restrain the operation of the terminal when inside of the aircraft. It may also be possible to suspend and activate the GPS terminal with reference to information relating to the operation time of the aircraft by storing that information into the GPS terminal. However, if the actual operation time is changed from the stored information, there is a risk that the GPS terminal will be activated during the flight. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a positioning terminal for generating position information of an object being transported. The positioning terminal includes a radio frequency identification (RFID) module for storing status information of the object relative to at least two predefined locations, and a communication module for sending position information of the object to a control center. A controller reads the status information from the RFID module at predefined intervals, and controls activation of the communication module based on the status information. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of a positioning terminal in accordance with one embodiment of present invention; 
       FIG. 2  is a diagram of an environment in which the positioning terminal of  FIG. 1  is implemented in accordance with one embodiment of the present invention; 
       FIGS. 3(   a )- 3 ( c ) are sample formats of a memory in an RFID module shown in  FIG. 1 ; 
       FIG. 4  is a sample database of flight information, which may be accessed by the positioning terminal of  FIG. 1 ; 
       FIG. 5  is a flowchart describing a process for tracking the positioning terminal in accordance with one embodiment of the present invention; and 
       FIG. 6  is a flowchart describing a process for tracking the positioning terminal in accordance with another embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention will be explained below with reference to the accompanying drawings.  FIG. 1  illustrates a structure of a positioning terminal  1  in accordance with one embodiment of the present invention. The positioning terminal  1  is adapted to be used for tracking the position of a freight or any moving object from a control center (not shown). The position information of the freight such as the latitude and the longitude is obtained by transmitting and receiving signals to and from an artificial satellite, and by transmitting and receiving signals to and from the control center. 
   The positioning terminal  1  is provided with a radio frequency identification (RFID) module  2 , a global positioning system (GPS) module  3 , a communication module  4  and a terminal controller  5 . The RFID module  2  includes an antenna and an IC module. The GPS module  3  is provided to obtain the position information of the positioning terminal  1 , such as the latitude and the longitude, by transmitting and receiving the signals to and from an artificial satellite. The communication module  4  is provided for transmitting and receiving data to and from a control center including the position information obtained with the GPS module  3 . The communication module enables the control center to accumulate the position information of the positioning terminal  1 , and accordingly, the accompanying freight being transported. 
   The terminal controller  5  is used for reading data from the memory of the RFID module  2  and for controlling the functions of the GPS module  3  and the communication module  4 . The terminal controller  5  may be implemented as a software program adapted to run in a processor or it may also be implemented as a firmware or using hard circuitry. 
   Tracking of a freight by the positioning terminal  1  is now explained with reference to  FIG. 2 . The present invention assumes transportation of a freight by an aircraft, as one example. However, land and sea transportation are also contemplated. 
   At the start, the positioning terminal  1  is made to accompany the freight or object being transported. Typically, freight is transported to the departing airport by land transportation and passed through an RFID reader/writer  6  provided at the departing airport, where a predetermined value is written in the predetermined area of an RFID memory  21  in the RFID module  2 . An example of the RFID memory  21  is shown in  FIG. 3(   a ), which shows that a flag is set in the “departing airport flag” field. 
   The freight having completed the process at the departing airport is then passed through an RFID reader/writer  7  provided at the arriving airport. Here, another predetermined value is written to the predetermined area of the RFID memory  21  provided in the RFID module  2 . In the example shown in  FIG. 3(   a ), a flag is set in the “arriving airport flag” field. The freight is then transported by land transportation to its next destination. 
     FIGS. 3(   a )- 3 ( c ) illustrate different examples of the structure of the RFID memory  21  provided in the RFID module  2 . The RFID memory  21  of  FIG. 3(   a ) is an example of the memory provided with the fields for the “departing airport flag” and the “arriving airport flag”. When the freight passes through the RFID reader/writer  6  provided at the departing airport, “1” is written to the “departing airport flag” field, and when the freight passes through the RFID reader/writer  7  provided at the arriving airport, “1” is written to the “arriving airport flag” field. 
     FIG. 3(   b ) is an example in which the RFID memory  21  is provided with field for “departing airport time” and “arriving airport time”. The respective times are written when the freight passes through the RFID reader/writers  6 ,  7  at the departing airport and arriving airport, respectively. The RFID memory  21  of  FIG. 3(   c ) is provided with a field for “scheduled arrival time” in addition to the fields for the departing and arriving times shown in  FIG. 3(   b ). This field is provided to enable the RFID reader/writer  6  of the departing airport to write the scheduled arrival time at the arriving airport. 
   The scheduled arrival time for each flight number is normally listed in a typical operation time table  8  illustrated in  FIG. 4 , which may be stored in a storage device of an airport computer system accessible by the RFID reader/writers  6 ,  7 . For example, in the case where a freight is loaded in the flight number “FJ201”, the RFID reader/writer  6  at the departing airport writes the value “13:15” from the “arrival time” field read from the operation time table  8 , in the “scheduled arrival time” field of the RFID memory  21 . 
     FIG. 5  illustrates a process for tracking the position of a freight in accordance with one embodiment of the present invention. The RFID module  2  is assumed to be provided with the RFID memory  21  shown in  FIG. 3(   a ). In steps S 51  to S 53 , a polling process is executed, where the predetermined area of the RFID memory  21  is read every predetermined time. More specifically, in step S 51 , data is read from the “departing airport flag” field of the RFID memory  21  by the terminal controller  5 . 
   In step S 52 , it is determined whether the departing airport flag is set from the read data. For example, whether the value “0” has been updated to “1” is determined. If the value “1” has been written as the predetermined value in the “departing airport flag” field of the RFID memory  21  by the RFID reader/writer  6  of the departing airport, the process goes to step S 54 . If not, the process goes to step S 53  for a predetermined time period, after which the process goes back to step S 51 . The predetermined time period in the step S 53  may be set so as to minimize power consumption of the positioning terminal  1 . 
   In step S 54 , the terminal controller  5  executes the operations to inactivate the GPS module  3  and the communication module  4 . In steps S 55  to S 57 , the polling process similar to that of steps S 51  to S 53  is also executed in order to monitor the “arriving airport flag” field of the RFID memory  21 . In step S 55 , data is read from the “arriving airport flag” field of the RFID memory  21  instead of “Departing airport flag” as in step S 51 . 
   In step S 56 , whether the read data is a predetermined value is determined. In other words, a determination is made as to whether the arriving airport flag is set. If “1” has been written as the predetermined value in the “arriving airport flag” field of the RFID memory  21  by the RFID reader/writer  7  at the arriving airport, the process goes to the step S 58 . If not, the process goes to step S 57  for a predetermined time period, after which the process goes back to step S 55 . In step S 58 , operations of the GPS module  3  and the communication module  4  are activated again by issuing a control command to these modules by the terminal controller  5 . 
   In the RFID memory  21  of  FIG. 3(   b ), the current time is written in the RFID memory  21  in place of the predetermined flag. As such, the conditions in steps S 52  and S 56  may also be satisfied when the departing airport time and the arriving airport time are written in their respective fields of the RFID memory  21 . 
   The flowchart of  FIG. 6  illustrates an example of the process in which the “scheduled arrival time” is written in the RFID memory  21  shown in  FIG. 3(   c ) by the RFID reader/writer  6  at the departing airport. Although not illustrated, the RFID reader/writer  6  is adapted to access the operation time table  8  (shown in  FIG. 4)  available from the airport computer system. The corresponding scheduled arrival time from the table  8  is written in the “scheduled arrival time” field of the RFID memory  21  at the time the freight and the accompanying positioning terminal  1  pass through and make communication with the RFID reader/writer  6  at the departing airport. In the example illustrated in  FIG. 3(   c ), the time “13:15” is written in the “scheduled arrival time” field. 
   The polling process in the steps S 61  to S 64  are similar to the processes in steps S 51  to S 54  of  FIG. 5 . In step S 65 , time data is read from the “scheduled arriving time” field of the RFID memory  21 . In step S 66 , all functions other than the function required for determining whether the scheduled arrival time has come, are suspended until the actual scheduled arrival time. 
   In the example of  FIG. 5 , the terminal controller  5  executes the processes for checking for the arriving airport flag in steps S 55  to S 57 , even during the flight. Accordingly, operations of the positioning terminal  1  consume some electric power, although only a little. However, in the example of  FIG. 6 , since the process of step S 66  is executed, the same processes in steps S 67  to S 69  for checking for the arriving airport flag are not executed until the scheduled arrival time. In this manner, operations and power consumption can be restrained. 
   It is contemplated that a deviation may occur between the scheduled arrival time and the actual arrival time of the aircraft. However, in the environment in which the present invention is applied, it is desired that no signal from the GPS module  3  or the communication module  4  be generated within the aircraft. Therefore, the restarting functions of the GPS module  3  immediately after arriving at the arriving airport is low in comparison with the importance of the condition described above. Accordingly, the process of step S 66  is effective for its intended purpose. To prevent the GPS module  3  from restarting while the freight and the positioning terminal  1  are still loaded in the aircraft, the terminal controller  5  recognizes arrival at the arriving airport through communication with the RFID module  2 . 
   The polling processes in steps S 67  to S 68  for monitoring the “arrival airport flag” field of the RFID memory  21  are similar to those of steps S 55  to S 57  in  FIG. 5 . The GPS module  3  and the communication module  4  are activated in step S 70  when the flag is set in the “arriving airport flag” field of the RFID memory  21 . 
   The present invention is not limited only to the embodiments disclosed above but allows various changes and modifications without departing from the scope of claims. 
   According to the present invention, the GPS and the communication functions of a positioning terminal for tracking the position information of a freight can be automatically inactivated without any manual operations, so that generation of electric waves can be restrained during transportation in an aircraft. Moreover, operations such as GPS function or the like can be reactivated when transportation by the aircraft is terminated. 
   While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims. 
   Various features of the invention are set forth in the appended claims.