Tracking objects crossing a border line between two zones
The present invention discloses a tracking apparatus and system thereof, useful for objects affixed with a smart tags entering and exiting an enclosed area through a gate. A gate consists of two directional antennas directed respectively inward and outward from the gate crossing line and connected to an RF beacon. Each smart tag affixed to an object approaching the gate area, receives a transmission of ID associated with each directional antenna. The smart tag detects crossing of the gate line and direction of crossing by method of processing the ID of the two directional antennas. The detected crossing data is transmitted via a wireless communication link, to a base station located at the enclosed zone. The base station transmits the gate detection data to a service center.
1. An apparatus for detecting the crossing of a border line section between a first zone and a second zone, comprising:
i. an antenna assembly located near said border line section, comprising:
(a) a first antenna section connected to a first transmitter, having a directional antenna with a radiating element oriented in a first direction and a radiation pattern aligned to radiate greater power in the first direction, and
(b) a second antenna section connected to a second transmitter, having a directional antenna with a radiating element oriented in a second direction opposite the first direction and a radiation pattern aligned to radiate greater power in the second direction;
wherein said first antenna section is directed from said border line section toward said first zone and said second antenna section is directed from said border line toward said second zone, and
ii. a smart tag that can be affixed to an object;
wherein said smart tag detects an event of said smart tag crossing said border line section, by receiving transmission of identification data of said first antenna section but not of said second antenna section when said smart tag is in said first zone, and then receiving transmission of identification data of said first antenna section and said second antenna section simultaneously, and then receiving transmission of identification data of said second antenna section but not of said first antenna section when said smart tag is in said second zone and then detecting that receipt of said transmission of identification data of said second antenna section has stopped while transmission of identification data of said first antenna section is not being received.
2. The apparatus according to claim 1 , wherein said first antenna section comprises a first linear antenna and said second antenna section comprises a second linear antenna, wherein said linear antennas are mounted back to back.
3. The apparatus according to claim 2 , wherein said first linear antenna is connected to a first channel of a beacon and said second linear antenna is connected to a second channel of said beacon.
4. The apparatus according to claim 1 , comprising a phased antenna array driven by an RF signal for configuring a radiation pattern similar to a first linear antenna and a second linear antenna mounted back to back.
5. The apparatus according to claim 2 , wherein said first linear antenna is connected to a first beacon and said second linear antenna is connected to a second beacon.
6. An apparatus according to claim 1 configured as a tracking system, comprising a plurality of smart tags affixed to a plurality of objects, wherein said smart tags transmit to a base station of said system via a wireless communication link, reports associated with said detected border line section crossing from said first zone to said second zone and vice versa.
7. The tracking system according to claim 6 , wherein said base station is connected via an IP network to a service center comprising a central processing server and a customer application server.
8. The tracking system according to claim 6 , comprising an enclosed zone and at least one gate, each of said plurality of smart tags detects gate entrance and gate exit and reports to said service center said gate entrance and gate exit.
9. The tracking system according to claim 6 , wherein said cross line section between said first zone and said second zone are in an outdoor setting.
10. A method for detecting the crossing of a border line section between a first zone and a second zone from said first zone to second zone and vice versa, comprising:
i. providing an antenna; said antenna comprising;
(a) a first antenna section connected to a first transmitter, having a directional antenna with a radiating element oriented in a first direction and a radiation pattern aligned to radiate greater power in the first direction, and
(b) a second antenna section connected to a second transmitter, having a directional antenna with a radiating element oriented in a second direction opposite the first direction and a radiation pattern aligned to radiate greater power in the second direction;
said first antenna section is directed from said border line section toward said first zone and said second antenna section is directed from said border line section toward said second zone, and
ii. providing a smart tag affixed to an object;
wherein detecting an event of said smart tag crossing said border line section is processed by a tag state machine, the detecting comprising:
(a) receiving by said smart tag identification transmission of said first antenna section but not of said second antenna section when said smart tag is in said first zone and then
(b) receiving transmission of identification data of said first antenna section and said second antenna section simultaneously, and then
(c) receiving identification transmission of said second antenna section but not of said first antenna section when said smart tag is in said second zone, and then
(d) detecting that receipt of said transmission of identification data of said second antenna section has stopped while transmission of identification data of said first antenna section is not being received.
11. The method according to claim 10 , comprising assigning a first integer as identification number for said first antenna section and a second integer as identification number for said second antenna section.
12. The method according to claim 11 , comprising assigning said first integer an even number and assigning said second integer an odd number greater by one from said first integer.
13. The method according to claim 10 , comprising providing said detection of crossing said border line section by said tag state machine; said state machine comprising a first branch and a second branch.
14. The method according to claim 13 , comprising operating continuously a receiver of said smart tag receiver during a standby state of said state machine.
15. The method according to claim 13 , comprising entering a start state of said state machine when said first antenna section or said second antenna section are transmitting identification data.
16. The method according to claim 14 , comprising entering a lock state and staying in said lock state of said state machine when said smart tag is receiving said identification transmission from only said first antenna section or only from second antenna section.
17. The method according to claim 13 , further comprising entering a crossing report state of said state machine when receipt of said second antenna section identification transmission stops.
18. The method according to claim 13 , comprising entering a sleep state of said state machine after detecting said line section crossing from said first zone to said second zone.
19. The tracking system according to claim 7 , comprising an enclosed zone and at least one gate, each of said plurality of smart tags detects gate entrance and gate exit and reports to said service center said gate entrance and gate exit.
20. An apparatus for detecting the crossing of a border line section between a first zone and a second zone, comprising:
a smart tag configured to be affixed to an object movable between the first zone and the second zone, said smart tag configured to detect an event of said smart tag crossing said border line section, by:
receiving transmission of identification data of a first antenna section but not of a second antenna section when said smart tag is in said first zone and then
receiving transmission of identification data of said first antenna section and said second antenna section simultaneously, and then
receiving transmission of identification data of said second antenna section but not of said first antenna section when said smart tag is in said second zone and then
detecting that receipt of said transmission of identification data of said second antenna section has stopped while transmission of identification data of said first antenna section is not being received;
wherein said first antenna section is located near said border line section and connected to a first transmitter, said first antenna section having a directional antenna with a radiating element oriented in a first direction and a radiation pattern aligned to radiate greater power in the first direction, said second antenna section is located near said border line section and connected to a second transmitter said second antenna section having a directional antenna with a radiating element oriented in a second direction opposite the first direction and a radiation pattern aligned to radiate greater power in the second direction; and said first antenna section is directed from said border line section toward said first zone and said second antenna section is directed from said border line section toward said second zone.
21. The method of claim 10 , further comprising determining that the smart tag has been near the border line but has not crossed the border line if the identification transmission of either the first or second antenna section is detected, but steps (a), (b) and (d) are not all performed sequentially.