TWI453448B - Methods and systems for detecting objects through - Google Patents

Description

Method and system for detecting object passage

The present invention relates to an object detecting method and system thereof, and more particularly to a method and system for detecting object passage.

Most of the methods for detecting object passing are mainly optical detection methods, such as the method for detecting the passage of objects disclosed in Japanese Patent No. I242652, which uses a plurality of light-emitting elements and a plurality of receiving elements to constitute a detective. The system is measured and the interception of the object is performed by the light interception method. However, the optical detection method described above causes a significant increase in the cost of detecting the system due to the use of a relatively large number of illuminating and receiving components. In addition, the extensive use of illuminating and receiving components also results in a significant increase in power loss in the detection system.

Therefore, it is necessary to provide an innovative and progressive method of detecting object passage and its system to solve the above problems.

The invention provides a method for detecting the passage of an object, the method comprising the steps of: (a) providing an object passing area; (b) providing a wireless identification reader on a side of the object passing area, the wireless identification reading The device has a first polarized antenna capable of transmitting a first polarized wave to a metal portion of a passing object, the metal portion capable of reflecting the first polarized wave and converting the first polarized wave And a (c) a wireless identification tag having a second polarization antenna, the second polarization The polarization direction of the antenna is opposite to the polarization direction of the first polarized antenna to make the second pole The antenna can receive the second polarized wave to activate the wireless identification tag, thereby determining that the object passes.

The invention further provides a system for detecting the passage of an object, comprising: at least one wireless identification reader disposed on one side of an object passing region, the wireless identification reader having a first polarized antenna, the first pole The antenna can emit a first polarized wave to a metal portion of a passing object, the metal portion can reflect the first polarized wave and convert the first polarized wave into a polarized wave having one of opposite polarization directions And at least one wireless identification tag is disposed in a reflection direction of the first polarized wave, the wireless identification tag has a second polarized antenna, and a polarization direction of the second polarized antenna is coupled to the first polarization The polarization direction of the antenna is opposite, and the second polarized antenna can receive the second polarized wave to activate the wireless identification tag, thereby determining that the object passes.

In the present invention, two polarized antennas having opposite polarization directions are respectively disposed 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 a polarization direction reversal. Features that enable the detection of object passage. The invention has the effects of reducing system construction cost, reducing system power loss, preventing adjacent multi-region objects from detecting interference and improving system reliability.

Figure 1 is a flow chart showing the method of detecting the passage of an object of the present invention. Figure 2 is a schematic illustration of the system of the present invention for detecting the passage of objects. Referring to step S11 and FIG. 2 of FIG. 1 , an object passing area a is provided, and the object passing area a is selected from the following ones: a vehicle passage, a production line, and a logistics area. In the present embodiment, the object passing area a is a vehicle passage.

Referring to step S12 and FIG. 2 of FIG. 1 , a wireless identification reader (RFID reader) 10 is disposed 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 emit a first polarized wave W1 to a metal portion 21 passing through the object 20, the metal portion 21 can reflect the first polarized wave W1 and the first polarized wave W1 is converted into a second polarized wave W2 which is opposite in polarization direction. In the present embodiment, the object 20 is a vehicle, and the metal portion 21 is a vehicle sheet metal portion.

In addition, the wireless identification reader 10 can be fixed to a rod R, and the first polarized antenna 11 is selected from the group consisting of a circularly polarized antenna and an elliptically polarized antenna.

Please refer to step S13 and FIG. 2 of FIG. 1 to set a wireless identification tag (RFID tag) 30 in the direction of reflection of the first polarized wave W1. The wireless identification tag 30 has a second polarized antenna 31. The polarization direction of the polarized 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 to activate the wireless identification tag 30. Further, it is determined that the object passes.

Please refer to FIG. 3, which is a schematic diagram of reading after the wireless identification tag is activated. After the wireless identification tag 30 is activated, the second polarized antenna 31 transmits another second polarized wave W2' to the metal portion 21 of the passing object 20, and the metal portion 21 can reflect the other second polarized wave. W2' and converting the other second polarized wave W2' into another first polarized wave W1' having the opposite polarization direction, the first polarized antenna 11 of the wireless identification reader 10 being capable of receiving the other The first polarized wave W1' is judged to pass the object.

In this embodiment, the wireless identification tag 30 can also be fixed on the lever R and spaced apart from the wireless identification reader 10, and the second polarized antenna 31 is selected from one of the following: a circular pole Antennas and elliptical polarized antennas.

In addition, since the polarization direction of the second polarized antenna 31 is opposite to the polarization direction of the first polarized antenna 11, the first polarized antenna of the wireless identification reader 10 when no object passes The first polarized wave W1 emitted by 11 cannot be converted into the second polarized wave W2 having the opposite polarization direction, and the second polarized antenna 31 cannot receive the first polarized wave having a different polarization direction. W1, the wireless identification tag 30 cannot be activated and read; conversely, when an object passes, the first polarized wave W1 emitted by the first polarized antenna 11 of the wireless identification reader 10 is reflected. And converting to the second polarized wave W2 having the opposite polarization direction, the second polarized antenna 31 can receive the second polarized wave W2 to activate the wireless identification tag 30, thereby determining that the object passes.

Figure 4 shows the electric field vector distribution of a circularly polarized wave. Figure 5 shows a schematic diagram of left-handed and right-handed circularly polarized waves. Referring to FIG. 2, FIG. 4 and FIG. 5, in the embodiment, when the first polarized antenna 11 and the second polarized antenna 31 are circularly polarized antennas, the second polarized antenna 31 is satisfied. If the polarization direction of the first polarized antenna 11 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 circularly polarized antenna, the wireless identification tag 30 The second polarized antenna 31 must be a left-handed circularly polarized antenna. In this case, 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 wireless identification reader 10 is in the first polarization day The line 11 is a left-handed circularly polarized antenna, and the second polarized antenna 31 of the wireless identification tag 30 must be a right-handed circularly polarized antenna. In this case, the first polarized wave is a left-handed circularly polarized wave, and the first The 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 electromagnetic wave theory, when a uniform plane wave is incident on a perfect conductor, the boundary condition of the interface between the two media needs to satisfy the continuity of the tangential component of the electric field, and the tangential component of the electric field on the surface of the perfect conductor is zero, so that |Ei (incident The electric field component)|+|Er (reflected electric field component)|=0, that is, Er=-Ei, wherein the direction of the magnetic field Hi of the incident wave a _ni and the magnetic field Hr of the reflected wave a _{nr are} unchanged, and the electric field direction of the electromagnetic wave is just right. Reflected at 180 degrees. Therefore, if the incident plane wave is a circularly polarized wave, it is still a circularly polarized wave after reflection, but the direction of rotation of the circular polarization is just the opposite, in other words, when the right (left) circularly polarized wave is incident on a perfect conductor, The reflected wave will be converted into a left (right) circularly polarized wave; likewise, when the right (left) elliptically polarized wave is incident on a perfect conductor, its reflected wave will be converted into a left (right) spiral elliptical pole. Wave.

Fig. 7 shows an electric field vector distribution diagram of an elliptically polarized wave. Figure 8 shows a schematic diagram of left-handed and right-handed elliptical polarized waves. Referring to FIG. 7 and FIG. 8 , in another embodiment, when the first polarized antenna 11 and the second polarized antenna 31 are elliptically polarized antennas, the pole of the second polarized antenna 31 is satisfied. The condition that the direction of polarization is opposite to the polarization direction of the first polarized antenna 11 is the second of the wireless identification tag 30 if the first polarized antenna 11 of the wireless identification reader 10 is a right-handed elliptical polarized antenna. 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 still 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.

Referring to FIG. 2 again, the system for detecting object passage 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 disposed on one side of an object passing area a. The wireless identification reader 10 has a first polarized antenna 11 capable of transmitting a first polarized wave. W1 to a metal portion 21 passing through the object 20, the metal portion 21 is capable of reflecting the first polarized wave W1 and converting the first polarized wave W1 into a second polarized wave W2 having one of opposite polarization directions. In the present embodiment, the object passing area a is a vehicle passage, the object 20 is a vehicle, and the metal portion 21 is a vehicle sheet metal portion. In addition, the wireless identification reader 10 can be fixed to a rod R, and the first polarized antenna 11 is selected from the group consisting of a circularly polarized antenna and an elliptically polarized antenna.

The wireless identification tag 30 is disposed in a reflection direction of the first polarized wave W1, and the wireless identification tag 30 has a second polarized antenna 31, and the polarization direction of the second polarized antenna 31 is coupled to the first pole. The polarization direction of the antenna 11 is reversed, and the second polarization antenna 31 can receive the second polarization W2 to activate the wireless identification tag 30, thereby determining that the object passes. In this embodiment, the wireless identification tag 30 can also be fixed on the lever R and spaced apart from the wireless identification reader 10, and the second polarized antenna 31 is selected from one of the following: a circular pole Antennas and elliptical polarized antennas.

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

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

Referring to step S93, the vehicle detection state is determined. When the detection RFID tag information is read, it is determined that the vehicle is detected to pass, and the detection state is set to TRUE (correct).

Please refer to FIG. 10, which is a schematic diagram showing a system for detecting the passage of an object according to a second embodiment of the present invention. The system for detecting the passage of an object according to the second embodiment of the present invention includes two wireless identification readers (RFID readers) 10 and two wireless identification tags (RFID tags) 30. The wireless identification readers 10 are respectively disposed on two sides of an object passing area a. Each of the wireless identification readers 10 has a first polarized antenna 11 , and each of the first polarized antennas 11 can emit a first a polarized wave W1 to a metal portion 21 passing through the object 20, the metal portion 21 being capable of reflecting each of the first polarized waves W1 and converting each of the first polarized waves W1 into one of opposite polarization directions. Polarized wave W2.

The wireless identification tags 30 are respectively disposed in the reflection directions of the first polarized waves W1, and each of the wireless identification tags 30 has a second polarized antenna 31, and the polarization directions of the second polarized antennas 31 are respectively In contrast to the polarization directions of the first polarized antennas 11, each of the second polarized antennas 31 can receive each of the second polarized waves W2 and actuate the wireless identification tags 30 to determine the passage of the objects.

Figure 11 is a diagram showing the information of the system for detecting the passage of an object according to the second embodiment of the present invention. Process flow chart. Please refer to steps S111 of FIG. 10 and FIG. 11 to start the two RFID readers.

Referring to step S112, the RFID tag information is read, and it is determined whether the RFID tag information is read, whether the RFID tag information for the detection is read, and whether other RFID tag information is read.

Referring to step S113, the vehicle detection state is determined. The RFID tags A and B must be read at the same time, and the detected vehicles are determined when the detection states of both readers are TRUE (correct). Through the reader settings.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the scope of the present invention. The scope of the invention should be as set forth in the appended claims.

10‧‧‧Wireless identification reader

11‧‧‧First polarized antenna

20‧‧‧ objects

21‧‧‧Metal parts

30‧‧‧Wireless identification tag

31‧‧‧Second-polarized antenna

A‧‧‧object passage area

a _ni ‧‧‧incident wave

a _nr ‧‧‧ reflected wave

Ei‧‧‧incident electric field component

Er‧‧‧reflected electric field component

Hi‧‧‧The magnetic field of the incident wave

Hr‧‧‧ reflected wave magnetic field

R‧‧‧ rods

W1‧‧‧First polarized wave

W1'‧‧‧ another first polarized wave

W2‧‧‧Second polarized wave

W2'‧‧‧ another second polarized wave

1 is a flow chart showing a method for detecting the passage of an object according to the present invention; FIG. 2 is a schematic view showing a system for detecting the passage of an object according to the present invention; FIG. 3 is a schematic diagram showing reading after the wireless identification tag is actuated; FIG. 5 shows a schematic diagram of left-handed and right-handed circularly polarized waves; FIG. 6 shows a schematic diagram of incident and reflected waves of electromagnetic waves incident on a perfect conductor; FIG. 7 shows an electric field vector distribution diagram of elliptically polarized waves; Schematic diagram of left-handed and right-handed elliptical polarized waves; FIG. 9 is a flow chart showing information processing of the system for detecting object passage of the present invention; FIG. 10 is a schematic diagram showing a system for detecting the passage of an object according to a second embodiment of the present invention; and FIG. 11 is a flow chart showing the information processing of the system for detecting the passage of an object according to the second embodiment of the present invention.

10‧‧‧Wireless identification reader

11‧‧‧First polarized antenna

20‧‧‧ objects

21‧‧‧Metal parts

30‧‧‧Wireless identification tag

31‧‧‧Second-polarized antenna

A‧‧‧object passage area

R‧‧‧ rods

W1‧‧‧First polarized wave

W2‧‧‧Second polarized wave

Claims (24)

A method for detecting passage of an object, comprising the steps of: (a) providing an object passage area; (b) providing a wireless identification reader on a side of the object passage area, the wireless identification reader having a first pole The first polarized antenna can emit a first polarized wave to a metal portion of a passing object, the metal portion can reflect the first polarized wave and convert the first polarized wave into a polarized direction a second polarized wave; and (c) a wireless identification tag disposed in a direction of reflection of the first polarized wave, the wireless identification tag having a second polarized antenna, and a polarization direction of the second polarized antenna And the polarization direction of the first polarized antenna is opposite, so that the second polarized antenna can receive the second polarized wave to activate the wireless identification tag, thereby determining that the object passes. The method for detecting the passage of an object according to claim 1, wherein in the step (b), the first polarized antenna of the wireless identification reader is selected from the group consisting of a circularly polarized antenna and an elliptically polarized antenna. The method for detecting the passage of an object according to claim 1, wherein in the step (c), the second polarized antenna of the wireless identification tag is selected from the group consisting of a circularly polarized antenna and an elliptically polarized antenna. The method for detecting the passage of an object according to claim 1, wherein in the step (b), the first polarized antenna of the wireless identification reader is a right-handed circularly polarized antenna, and the first polarized wave is right The circularly polarized wave is a left-handed circularly polarized wave; in the step (c), the second polarized antenna of the wireless identification tag is a left-handed circularly polarized antenna. The method for detecting the passage of an object according to claim 1, wherein in the step (b), the first polarized antenna of the wireless identification reader is a left-handed circularly polarized antenna, and the first polarized wave is a left-handed circle. a polarized wave, the second polarized wave is a right-handed circularly polarized wave; in the step (c), the second polarized antenna of the wireless identification tag is a right-handed circularly polarized antenna. The method for detecting the passage of an object according to claim 1, wherein in the step (b), the first polarized antenna of the wireless identification reader is a right-handed elliptical polarized antenna, and the first polarized wave is right The elliptical polarized wave is a left-handed elliptical polarized wave; in the step (c), the second polarized antenna of the wireless identification tag is a left-handed elliptical polarized antenna. The method for detecting the passage of an object according to claim 1, wherein in the step (b), the first polarized antenna of the wireless identification reader is a left-handed elliptical polarized antenna, and the first polarized wave is a left-handed ellipse. a polarized wave, the second polarized wave is a right-handed elliptical polarized wave; and in the step (c), the second polarized antenna of the wireless identification tag is a right-handed elliptical polarized antenna. The method for detecting the passage of an object according to any one of claims 1 to 7, wherein in the step (c), after the wireless identification tag is activated, the second polarized antenna transmits another second polarized wave. To the metal portion of the passing object, the metal portion can reflect the other second polarized wave and convert the other second polarized wave into another first polarized wave having the opposite polarization direction, the wireless identification reading The first polarized antenna of the device can receive the other first polarized wave to determine that the object passes. The method for detecting the passage of an object according to claim 1, wherein the object passage area is selected from the group consisting of a vehicle passage, a production line, and a logistics area. The method for detecting the passage of an object according to claim 1, wherein the object system is a vehicle. The method of detecting the passage of an object according to claim 10, wherein the metal portion of the object is a sheet metal portion of the vehicle. A system for detecting the passage of an object, comprising: at least one wireless identification reader disposed on one side of an object passing region, the wireless identification reader having a first polarized antenna, the first polarized antenna capable of transmitting a first polarized wave to a metal portion passing through the object, the metal portion being capable of reflecting the first polarized wave and converting the first polarized wave into a second polarized wave having one of opposite polarization directions; and at least one a wireless identification tag is disposed in a reflection direction of the first polarized wave, the wireless identification tag has a second polarized antenna, and a polarization direction of the second polarized antenna is coupled to a polarization of the first polarized antenna In the opposite direction, the second polarized antenna can receive the second polarized wave to activate the wireless identification tag, thereby determining that the object passes. The system for detecting the passage of an object according to claim 12, wherein the first polarized antenna of the wireless identification reader is selected from the group consisting of a circularly polarized antenna and an elliptically polarized antenna. The system for detecting the passage of an object according to claim 12, wherein the second polarized antenna of the wireless identification tag is selected from the group consisting of a circularly polarized antenna and an elliptically polarized antenna. The system for detecting the passage of an object according to claim 12, wherein the first polarized antenna of the wireless identification reader is a right-handed circularly polarized antenna, and the first polarized wave system is a right-handed circularly polarized wave. The second polarized wave system is a left circular pole The second polarized antenna of the wireless identification tag is a left-hand circularly polarized antenna. The system for detecting the passage of an object according to claim 12, wherein the first polarized antenna of the wireless identification reader is a left-handed circularly polarized antenna, and the first polarized wave system is a left-handed circularly polarized wave, The second polarized wave is a right-hand circularly polarized wave, and the second polarized antenna of the wireless identification tag is a right-handed circularly polarized antenna. The system for detecting the passage of an object according to claim 12, wherein the first polarized antenna of the wireless identification reader is a right-handed elliptical polarized antenna, and the first polarized wave system 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. The system for detecting the passage of an object according to claim 12, wherein the first polarized antenna of the wireless identification reader is a left-handed elliptical polarized antenna, and the first polarized wave system 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. The system for detecting the passage of an object according to any one of claims 12 to 18, wherein the second polarized antenna is capable of transmitting another second polarized wave to a metal portion of the passing object, the metal portion being capable of reflecting the Another second polarized wave and the other second polarized wave are converted into another first polarized wave having the opposite polarization direction, and the first polarized antenna of the wireless identification reader can receive the other first polarized wave The polarized wave is used to determine the passage of the object. The system for detecting the passage of an object as claimed in claim 12, wherein the object passes The passing area is selected from the group consisting of a vehicle passage, a production line, and a logistics area. The system of claim 12, wherein the object system is a vehicle. A system for detecting the passage of an object as described in claim 21, wherein the metal portion of the object is a sheet metal portion of the vehicle. A system for detecting the passage of an object according to claim 12, further comprising a lever, the wireless identification reader being fixed to the lever. The system of claim 23, wherein the wireless identification tag is fixed to the lever and spaced apart from the wireless identification reader.