CN103679090B - Method and system for detecting object passing - Google Patents

Abstract

The invention relates to a method and system for detecting the passage of an object. The method includes the following steps: (a) providing an object passage area; (b) setting a wireless identification reader on one side of the object passage area. The wireless identification reader has a first polarized antenna. The first polarized antenna can transmit a first polarized wave to a metal part of a passing object. The metal part can reflect the first polarized wave and convert the first polarized wave. Converting the polarized wave into a second polarized wave with the opposite polarization direction; and (c) setting a wireless identification tag in the reflection direction of the first polarized wave, the wireless identification tag having a second polarized antenna, the The polarization direction of the second polarized antenna is opposite to the polarization direction of the first polarized antenna, so that the second polarized antenna can receive the second polarized wave and activate the wireless identification tag, thereby determining Object passes.

Description

Method and system for detecting passage of objects

technical field

The present invention relates to an object detection method and its system, in particular to a method and its system for detecting the passage of an object.

Background technique

It is known that most of the methods for detecting the passage of objects are based on optical detection methods, such as the "method for detecting the passage of objects" disclosed in my country's Announcement Patent No. I242652, which uses a plurality of light-emitting elements and a plurality of receiving elements to form a detection system, and Interpretation of the passage of objects is performed using the light-interception method. However, the aforementioned optical detection method uses a considerable number of light-emitting and receiving elements, resulting in a significant increase in the construction cost of the detection system. In addition, a large number of light-emitting and receiving elements will also greatly increase the power consumption of the detection system.

Therefore, it is necessary to provide an innovative and progressive method and system for detecting the passing of objects to solve the above problems.

Contents of the invention

The invention provides a method for detecting the passage of an object, which includes the following steps: (a) providing an object passing area; (b) setting a wireless identification reader on one side of the object passing area, and the wireless identification reads The device has a first polarized antenna capable of transmitting a first polarized wave to a metal part passing through an object, the metal part capable of reflecting the first polarized wave and converting the first polarized wave forming a second polarized wave opposite to the polarized direction; and (c) disposing a wireless identification tag in the reflection direction of the first polarized wave, the wireless identification tag having a second polarized antenna, the second polarized The polarization direction of the antenna is opposite to the polarization direction of the first polarized antenna, so that the second polarized antenna can receive the second polarized wave to actuate the wireless identification tag, and then determine the passing of the object.

The present invention also provides a system for detecting the passing of an object, including: at least one wireless identification reader, which is arranged on one side of an object passing area, the wireless identification reader has a first polarized antenna, and the first polarized The polarization antenna can transmit a first polarized wave to a metal part passing through the object, and the metal part can reflect the first polarized wave and convert the first polarized wave into a second polarized wave with the opposite polarization direction and at least one wireless identification tag, which is arranged in the reflection direction of the first polarized wave, the wireless identification tag has a second polarized antenna, and the polarization direction of the second polarized antenna is the same as the first polarized wave The polarization direction of the antenna is opposite, and the second polarized antenna can receive the second polarized wave to actuate the wireless identification tag, and then judge the passing of the object.

In the present invention, two polarized antennas with opposite polarized directions are respectively arranged on the wireless identification reader and the wireless identification tag, and the reflected polarized wave after the antenna polarized wave is incident on the metal surface has the characteristic of polarized direction reversal , to realize the detection of object passing. The invention has the effects of reducing system construction cost, reducing system power consumption, preventing adjacent multi-area objects from passing through detection interference, and improving system reliability.

Description of drawings

Fig. 1 shows the flow chart of the method for detecting the passage of an object in the present invention;

Fig. 2 shows the schematic diagram of the system for detecting the passage of objects according to the present invention;

Figure 3 shows a schematic diagram of reading after the wireless identification tag is activated;

Figure 4 shows the electric field vector distribution diagram of circularly polarized waves;

Figure 5 shows a schematic diagram of left-handed and right-handed circularly polarized waves;

Fig. 6 shows the schematic diagram of incident wave and reflected wave of electromagnetic wave incident on a perfect conductor;

Fig. 7 shows the electric field vector distribution figure of elliptically polarized wave;

Figure 8 shows a schematic diagram of left-handed and right-handed elliptically polarized waves;

Fig. 9 shows the flow chart of information processing of the system for detecting the passing of objects in the present invention;

FIG. 10 shows a schematic diagram of a system for detecting passage of an object according to a second embodiment of the present invention; and

FIG. 11 shows a flow chart of information processing of the system for detecting the passing of objects according to the second embodiment of the present invention.

[Description of main component labels]

10 Wireless Identification Reader 11 First Polarized Antenna

20 objects 21 metal parts

30 Wireless Identification Tag 31 Second Polarized Antenna

A object passes through the region ani incident wave

Anr reflected wave Ei incident electric field component

Er the reflected electric field component Hi the magnetic field of the incident wave

Hr Magnetic field of reflected wave R Rod

W1 First polarized wave W1' Another first polarized wave

W2 second polarized wave W2' another second polarized wave

detailed description

Fig. 1 shows a flow chart of the method for detecting the passage of an object according to the present invention. Figure 2 shows a schematic diagram of the system for detecting the passage of objects according to the present invention. Please refer to step S11 of FIG. 1 and FIG. 2 to provide an object passing area a, the object passing area a is selected from one of the following: vehicle passage, production line and logistics area. In this embodiment, the object passing area a is a vehicle channel.

Please refer to step S12 of FIG. 1 and FIG. 2, a wireless identification reader (RFID reader) 10 is set on one side of the object passing area a, and the wireless identification reader 10 has a first polarized antenna 11. The first polarized antenna 11 can transmit a first polarized wave W1 to a metal part 21 passing through the object 20, and the metal part 21 can reflect the first polarized wave W1 and the first polarized wave W1 is transformed into a second polarized wave W2 with the opposite polarization direction. In this embodiment, the object 20 is a vehicle, and the metal part 21 is a sheet metal part of the vehicle.

In addition, the wireless identification reader 10 can be fixed on a rod R, and the first polarized antenna 11 is selected from one of the following: a circularly polarized antenna and an elliptical polarized antenna.

Please refer to step S13 of FIG. 1 and FIG. 2, and set a wireless identification tag (RFID tag) 30 in the reflection direction of the first polarized wave W1. The wireless identification tag 30 has a second polarized antenna 31. The polarization direction of the dipolar antenna 31 is opposite to the polarization direction of the first polarized antenna 11, so that the second polarized antenna 31 can receive the second polarized wave W2 and activate the wireless identification tag 30 , and then judge that the object passes through.

Please refer to FIG. 3 , which is a schematic diagram showing the reading of the wireless identification tag after it is actuated. After the wireless identification tag 30 is activated, the second polarized antenna 31 will transmit another second polarized wave W2' to the metal part 21 of the passing object 20, and the metal part 21 can reflect the other second polarized wave W2'. wave W2' and convert the other second polarized wave W2' into another first polarized wave W1' opposite to the polarization direction, the first polarized antenna 11 of the wireless identification reader 10 can receive the other A first polarized wave W1' is used to determine that the object has passed.

In this embodiment, the wireless identification tag 30 can also be fixed on the rod R, and separated from the wireless identification reader 10 by a certain distance, and the second polarized antenna 31 is selected from the following one: circular polarized and elliptical polarized antennas.

In addition, since the polarization direction of the second polarized antenna 31 is opposite to that of the first polarized antenna 11, when no object passes by, the first polarized antenna of the wireless identification reader 10 The first polarized wave W1 transmitted by 11 cannot be converted into the second polarized wave W2 with the opposite polarized direction, and the second polarized antenna 31 cannot receive the first polarized wave with different polarized directions W1, so the wireless identification tag 30 cannot be actuated and read; on the contrary, when an object passes by, the first polarized wave W1 emitted by the first polarized antenna 11 of the wireless identification reader 10 will be detected The second polarized wave W2 is reflected and converted into the opposite polarized direction. The second polarized wave W2 can be received by the second polarized antenna 31 to actuate the wireless identification tag 30 to determine the passing of an object.

Figure 4 shows the distribution of the electric field vector for a circularly polarized wave. FIG. 5 shows schematic diagrams of left-handed and right-handed circularly polarized waves. Please refer to FIG. 2, FIG. 4 and FIG. 5. In this embodiment, when the first polarized antenna 11 and the second polarized antenna 31 are circularly polarized antennas, in order to satisfy the requirements of the second polarized antenna 31 The polarization direction of the first polarized antenna 11 is opposite to that of the first polarized antenna 11. If the first polarized antenna 11 of the wireless identification reader 10 is a right-handed circularly polarized antenna, the wireless identification tag 30 The second polarized antenna 31 must be a left-handed circularly polarized antenna. At this time, the first polarized wave is a right-handed circularly polarized wave, and the second polarized wave is a left-handed circularly polarized wave.

In another embodiment, if the first polarized antenna 11 of the wireless identification reader 10 is a left-handed circularly polarized antenna, then the second polarized antenna 31 of the wireless identification tag 30 must be a right-handed circularly polarized antenna , at this time, the first polarized wave is a left-handed circularly polarized wave, and the second polarized wave is a right-handed circularly polarized wave.

Please refer to FIG. 6 , which is a schematic diagram showing incident waves and reflected waves of electromagnetic waves incident on a perfect conductor. In the theory of electromagnetic waves, when a uniform plane wave is incident on a perfect conductor, the boundary condition at the interface between the two media must satisfy the continuity of the tangent component of the electric field, while the tangent component of the electric field is zero on the surface of the perfect conductor, so that |Ei(incident Electric field component)|+|Er (reflected electric field component)|=0, that is, Er=-Ei, where the directions of the magnetic field Hi of the incident wave ani and the magnetic field Hr of the reflected wave anr remain unchanged, while the direction of the electric field of the electromagnetic wave is just 180 degrees of reflection. Therefore, if the incident plane wave is a circularly polarized wave, it will still be a circularly polarized wave after reflection, but the rotation direction of the circular polarization is just opposite. In other words, when the right (left) circularly polarized wave is incident on a perfect conductor, Its reflected wave will be converted into a left (right) circularly polarized wave; similarly, when a right (left) elliptical polarized wave is incident on a perfect conductor, its reflected wave will be converted into a left (right) elliptical polarized wave chemical wave.

Fig. 7 shows the electric field vector distribution diagram of elliptically polarized waves. FIG. 8 shows schematic diagrams of left-handed and right-handed elliptically polarized waves. Please refer to FIG. 7 and FIG. 8. In another embodiment, when the first polarized antenna 11 and the second polarized antenna 31 are elliptical polarized antennas, in order to satisfy the polarity of the second polarized antenna 31, The condition that the polarization direction is opposite to the polarization direction of the first polarized antenna 11, if the first polarized antenna 11 of the wireless identification reader 10 is a right-handed elliptical polarized antenna, then the second polarized antenna of the wireless identification tag 30 The polarized antenna 31 must be a left-handed elliptical polarized antenna. At this time, the first polarized wave is a right-handed elliptical polarized wave, and the second polarized wave is a left-handed elliptical polarized wave.

In yet another embodiment, if the first polarized antenna 11 of the wireless identification reader 10 is a left-handed elliptical polarized antenna, the second polarized antenna 31 of the wireless identification tag 30 must be a right-handed elliptical polarized antenna , at this time, the first polarized wave is a left-handed elliptical polarized wave, and the second polarized wave is a right-handed elliptical polarized wave.

Please refer to FIG. 2 again. The system for detecting the passage of objects of the present invention includes a wireless identification reader (RFID reader) 10 and a wireless identification tag (RFID tag) 30 . The wireless identification reader 10 is arranged on one side of an object passing area a, the wireless identification reader 10 has a first polarized antenna 11, and the first polarized antenna 11 can emit a first polarized wave W1 passes through a metal part 21 of the object 20, and the metal part 21 can reflect the first polarized wave W1 and convert the first polarized wave W1 into a second polarized wave W2 with an opposite polarization direction. In this embodiment, the object passing area a is a vehicle channel, the object 20 is a vehicle, and the metal part 21 is a vehicle sheet metal part. In addition, the wireless identification reader 10 can be fixed on a rod R, and the first polarized antenna 11 is selected from one of the following: a circularly polarized antenna and an elliptical polarized antenna.

The wireless identification tag 30 is set in the reflection direction of the first polarized wave W1, the wireless identification tag 30 has a second polarized antenna 31, and the polarization direction of the second polarized antenna 31 is the same as that of the first polarized wave. The polarization direction of the polarized antenna 11 is opposite, and the second polarized antenna 31 can receive the second polarized wave W2 to actuate the wireless identification tag 30 to determine the passing of an object. In this embodiment, the wireless identification tag 30 can also be fixed on the rod R, and separated from the wireless identification reader 10 by a certain distance, and the second polarized antenna 31 is selected from the following one: circular polarized and elliptical polarized antennas.

Fig. 9 shows a flow chart of information processing of the system for detecting the passage of an object according to the present invention. Please refer to step S91 in FIG. 3 and FIG. 9 to activate the RFID reader.

Please refer to step S92, read the RFID tag information, which is to judge whether the RFID tag information is read, judge whether the detection RFID tag information is read, and judge whether other RFID tag information is read.

Please refer to step S93 , judging the vehicle detection state, which is to determine that the vehicle has been detected to pass when the RFID tag information for detection is read, and the detection state is set to TRUE (correct).

Please refer to FIG. 10 , which is a schematic diagram showing a system for detecting passing objects according to a second embodiment of the present invention. According to the second embodiment of the present invention, the system for detecting passing objects includes two wireless identification readers (RFID readers) 10 and two wireless identification tags (RFID tags) 30 . The wireless identification readers 10 are respectively arranged on both sides of an object passing area a, and each of the wireless identification readers 10 has a first polarized antenna 11, and each of the first polarized antennas 11 can transmit a first A polarized wave W1 passes through a metal part 21 of the object 20, and the metal part 21 can reflect each of the first polarized waves W1 and convert each of the first polarized waves W1 into a second polarized wave W1 with the opposite polarization direction. Polarized wave W2.

The wireless identification tags 30 are respectively arranged in the reflection direction of each of the first polarized waves W1, each of the wireless identification tags 30 has a second polarized antenna 31, and the polarization direction of each of the second polarized antennas 31 is Opposite to the polarization direction of each of the first polarized antennas 11 , each of the second polarized antennas 31 can receive the second polarized waves W2 to activate each of the wireless identification tags 30 , and then determine the passing of an object.

FIG. 11 shows a flow chart of information processing of the system for detecting the passing of objects according to the second embodiment of the present invention. Please refer to step S111 in FIG. 10 and FIG. 11 to activate the two RFID readers.

Please refer to step S112, read the RFID tag information, which is to judge whether the RFID tag information is read, judge whether the detection RFID tag information is read, and judge whether other RFID tag information is read.

Please refer to step S113 to determine the detection status of the vehicle. It must read the RFID tags A and B for detection at the same time, and when the detection status of the readers on both sides is TRUE (correct), it is determined that the vehicle has passed the reader. settings.

The above-mentioned embodiments are only for illustrating the principles and functions of the present invention, but not for limiting the present invention. Therefore, those skilled in the art can modify and change the above-mentioned embodiments without departing from the spirit of the present invention. The scope of the claims of the present invention should be as listed in the scope of the above claims.

Claims (22)

1. A method for detecting the passing of an object, comprising the following steps: (a) provide an object passage area; (b) Installing a wireless identification reader on one side of the object passing area, the wireless identification reader has a first polarized antenna capable of transmitting a first polarized wave to a passing object a metallic portion of a metal portion capable of reflecting the first polarized wave and converting the first polarized wave into a second polarized wave of opposite polarization; and (c) setting a wireless identification tag in the reflection direction of the first polarized wave, the wireless identification tag has a second polarized antenna, and the polarization direction of the second polarized antenna is in the same direction as the first polarized antenna The polarized direction is opposite, so that the second polarized antenna can receive the second polarized wave to activate the wireless identification tag, and then judge the passing of the object, In step (c), after the wireless identification tag is activated, the second polarized antenna will emit another second polarized wave to the metal part of the passing object, and the metal part can reflect the other second polarized wave and converting the other second polarized wave into another first polarized wave opposite to the polarized direction, the first polarized antenna of the wireless identification reader can receive the other first polarized wave and determine Objects pass. 2. The method for detecting the passage of an object according to claim 1, wherein in step (b), the first polarized antenna of the wireless identification reader is selected from the group consisting of a circularly polarized antenna and an elliptical polarized antenna antenna. 3. The method for detecting the passing of an object according to claim 1, wherein in step (c), the second polarized antenna of the wireless identification tag is selected from the following one: a circularly polarized antenna and an elliptical polarized antenna. 4. The method for detecting an object passing according to claim 1, wherein in step (b), the first polarized antenna of the wireless identification reader is a right-handed circularly polarized antenna, and the first polarized wave is The right-handed circularly polarized wave, the second polarized wave is a left-handed circularly polarized wave; in step (c), the second polarized antenna of the wireless identification tag is a left-handed circularly polarized antenna. 5. The method for detecting the passage of an object according to claim 1, wherein in step (b), the first polarized antenna of the wireless identification reader is a left-handed circularly polarized antenna, and the first polarized wave is left-handed Circularly polarized waves, the second polarized waves are right-handed circularly polarized waves; in step (c), the second polarized antenna of the wireless identification tag is a right-handed circularly polarized antenna. 6. The method for detecting the passage of an object according to claim 1, wherein in step (b), the first polarized antenna of the wireless identification reader is a right-handed elliptical polarized antenna, and the first polarized wave is A right-handed elliptical polarized wave, the second polarized wave is a left-handed elliptical polarized wave; in step (c), the second polarized antenna of the wireless identification tag is a left-handed elliptical polarized antenna. 7. The method for detecting the passage of an object according to claim 1, wherein in step (b), the first polarized antenna of the wireless identification reader is a left-handed elliptical polarized antenna, and the first polarized wave is left-handed An elliptical polarized wave, the second polarized wave is a right-handed elliptical polarized wave; in step (c), the second polarized antenna of the wireless identification tag is a right-handed elliptical polarized antenna. 8. The method for detecting object passing according to claim 1, wherein the object passing area is selected from one of the following: vehicle passage, production line and logistics area. 9. The method for detecting passage of an object according to claim 1, wherein the object is a vehicle. 10. The method for detecting passage of an object according to claim 9, wherein the metal part of the object is a sheet metal part of a vehicle. 11. A system for detecting passage of an object comprising: At least one wireless identification reader is arranged on one side of an object passing area, the wireless identification reader has a first polarized antenna, and the first polarized antenna can emit a first polarized wave to a passing object a metallic portion of a metal portion capable of reflecting the first polarized wave and converting the first polarized wave into a second polarized wave of opposite polarization; and At least one wireless identification tag is arranged in the reflection direction of the first polarized wave, the wireless identification tag has a second polarized antenna, and the polarization direction of the second polarized antenna is in the same direction as the first polarized antenna The polarization direction is opposite, and the second polarized antenna can receive the second polarized wave to actuate the wireless identification tag, and then judge the passing of the object, The second polarized antenna can transmit another second polarized wave to the metal part of the passing object, and the metal part can reflect the other second polarized wave and convert the other second polarized wave into a polarization direction In contrast to the other first polarized wave, the first polarized antenna of the wireless identification reader can receive the other first polarized wave to determine that the object has passed. 12. The system for detecting passage of an object according to claim 11, wherein the first polarized antenna of the wireless identification reader is selected from one of the following: a circularly polarized antenna and an elliptical polarized antenna. 13. The system for detecting passage of an object according to claim 11, wherein the second polarized antenna of the wireless identification tag is selected from one of the following: a circularly polarized antenna and an elliptical polarized antenna. 14. The system for detecting passage of an object according to claim 11, wherein the first polarized antenna of the wireless identification reader is a right-handed circularly polarized antenna, and the first polarized wave is a right-handed circularly polarized wave, The second polarized wave is a left-handed circularly polarized wave, and the second polarized antenna of the wireless identification tag is a left-handed circularly polarized antenna. 15. The system for detecting passage of an object according to claim 11, wherein the first polarized antenna of the wireless identification reader is a left-handed circularly polarized antenna, the first polarized wave is a left-handed circularly polarized wave, and the first polarized wave is a left-handed circularly polarized wave. The second polarized wave is a right-handed circularly polarized wave, and the second polarized antenna of the wireless identification tag is a right-handed circularly polarized antenna. 16. The system for detecting passage of objects according to claim 11, wherein the first polarized antenna of the wireless identification reader is a right-handed elliptical polarized antenna, and the first polarized wave is a right-handed elliptical polarized wave, The second polarized wave is a left-handed elliptical polarized wave, and the second polarized antenna of the wireless identification tag is a left-handed elliptical polarized antenna. 17. The system for detecting passage of an object according to claim 11, wherein the first polarized antenna of the wireless identification reader is a left-handed elliptical polarized antenna, the first polarized wave is a left-handed elliptical polarized wave, and the first polarized wave is a left-handed elliptical polarized wave. The second polarized wave is a right-handed elliptical polarized wave, and the second polarized antenna of the wireless identification tag is a right-handed elliptical polarized antenna. 18. The system for detecting object passing according to claim 11, wherein the object passing area is selected from one of the following: vehicle passage, production line and logistics area. 19. The system for detecting passage of an object according to claim 11, wherein the object is a vehicle. 20. The system for detecting passage of an object according to claim 19, wherein the metal part of the object is a sheet metal part of a vehicle. 21. The system for detecting passage of an object according to claim 11, further comprising a pole, the wireless identification reader is fixed on the pole. 22. The system for detecting passage of an object according to claim 21, wherein the wireless identification tag is fixed on the pole and is separated from the wireless identification reader by a certain distance.