JP4702891B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system suitable for transmitting information using, for example, an air conditioning duct.

Conventionally, air conditioning control for office buildings, etc. is detected by sensors that detect environmental information such as temperature and humidity, actuators that are provided at openings in outlets such as ducts, and sensors that control the opening of openings. In response to the environmental information and the operation command from the user, an air conditioning control device that performs drive control of the actuator is provided.
Incidentally, sensors and actuators used for air-conditioning control are not necessarily provided at positions adjacent to the air-conditioning control device, and are generally installed at remote locations. In addition, this type of sensor or actuator is desired to be able to flexibly cope with a change in floor layout using, for example, a partition. For this reason, attempts have been made to wirelessly transmit data transmitted and received between these sensors and actuators and the air conditioning control device via a metal air conditioning duct (see, for example, Patent Document 1).

  Specifically, as shown in FIG. 12, the air-conditioning control device 1 that performs wireless transmission via the metal air-conditioning duct 2 receives electromagnetic waves (radio waves) from the sensor 11 via the interrogation antenna 3 provided in the air-conditioning duct 2. It is configured to include a transmission / reception unit 4 that receives environmental information transmitted using the control signal and transmits control data to the actuator 12 by electromagnetic waves (radio waves). The transmission / reception unit 4 is connected to a control unit 5 that controls the air conditioning control device 1, and receives temperature information transmitted from the sensor 11 through the air conditioning duct 2 by radio waves. The air conditioning control device 1 transmits a drive command to the actuator 12 by radio waves in order to maintain a desired temperature input to the air conditioning control device 1. An external power source 6 that drives the air conditioning control device 1 including the transmission / reception unit 4 and the control unit 5 is connected to the air conditioning control device 1.

  On the other hand, the sensor 11 and the actuator 12 transmit the environmental information detected by the sensor 11 via the response antenna 13 provided in the air conditioning duct 2 to the air conditioning control device 1 by radio waves, while the radio waves transmitted from the air conditioning control device 1. The transmission / reception unit 14 receives the operation command delivered by the response antenna 13 and gives the operation command to the actuator 12.

Power is supplied to the sensor 11 and the actuator 12 by an external power supply 15. As the external power source 15, a method of separately supplying a power supply line for supplying power to the sensor 11 and the actuator 12 and a method of providing a battery for driving the sensor 11 can be considered.
JP 2004-228691 A

  However, when data transmitted between the sensor 11 or the actuator 12 and the air conditioning control device 1 is wirelessly transmitted, an external power source 15 for driving the sensor 11 or the actuator 12 is necessary. For example, a power line is prepared. There is a problem that layout change is difficult. Further, when the sensor 11 is driven by a battery, replacement work must be periodically performed to prevent malfunction of the sensor 11, especially in a large-scale office building having a large number of sensors 11. There is also a problem that maintenance work becomes enormous, and there is a concern about malfunction of the air conditioner due to occurrence of battery replacement leakage.

  The present invention has been made in consideration of such circumstances, and its purpose is to eliminate the need for wiring and batteries for driving the sensor, and therefore flexibly respond to changes in the floor layout using partitions. A wireless communication system capable of being provided is provided.

In order to achieve the above-described object, the wireless communication system of the present invention measures an air conditioning duct made of a metal cylindrical body and a predetermined physical quantity, and the measured physical quantity is electromagnetic waves with a predetermined frequency in the air conditioning duct. A radio communication system having a measurement device that modulates and transmits, and an air conditioning control device that receives the electromagnetic wave transmitted by the measurement device into the air conditioning duct and receives the physical quantity conveyed by the electromagnetic wave,
The air-conditioning control device is positioned so as to protrude into the air-conditioning duct through a hole formed in the wall surface of the air-conditioning duct, and the electromagnetic wave transmitted by the measuring device with the electromagnetic wave having the first frequency. An interrogation antenna, a control device receiver connected to the interrogation antenna and receiving the physical quantity carried by the electromagnetic wave of the first frequency, and a control device receiver connected to the control device receiver. An external power supply unit that supplies power to operate the receiving unit, a power transmission unit that is connected to the external power supply unit and transmits electromagnetic waves of the second frequency, and is connected to the power transmission unit, A power transmission antenna that is positioned so as to protrude into the air conditioning duct through a hole formed in the wall surface, and that transmits an electromagnetic wave transmitted by the power transmission unit into the air conditioning duct;
The measurement device includes a measurement device transmission unit that modulates and transmits the measured physical quantity with an electromagnetic wave of the first frequency, and a hole that is connected to the measurement device transmission unit and is formed in a wall surface of the air conditioning duct. A response antenna that is positioned so as to project into the air conditioning duct through the section and sends out the electromagnetic wave transmitted by the measuring device transmitter into the air conditioning duct, and a hole formed in the wall surface of the air conditioning duct. through, is positioned so as to protrude within the air-conditioning duct, wherein a power receiving antenna for receiving the second electromagnetic wave frequency sent out by the transmission antenna, and is connected to the power receiving antenna, the receiving antenna receives A rectifying unit that rectifies electromagnetic waves in the second frequency range and extracts DC power, and a power storage unit that stores the DC power extracted by the rectifying unit,
The measuring device is driven by direct current power stored in the power storage unit.

  The wireless communication system described above receives electromagnetic waves (radio waves) transmitted from the power transmission antenna of the air conditioning control device to the air conditioning duct, and receives the DC power by rectifying the received electromagnetic waves (radio waves). Then, the measuring device is driven by a non-power source using the DC power stored in the power storage unit. The environmental information measured by the measuring device is transmitted to the air conditioning duct via the response antenna, and taken into the air conditioning control device from the question antenna.

The wireless communication system of the present invention includes an air-conditioning duct made of a metal cylinder, an air-conditioning control device that sends control data modulated by electromagnetic waves of a predetermined frequency into the air-conditioning duct, and the air-conditioning control device. A wireless communication system having a drive device that receives predetermined control data sent into the air conditioning duct and executes a predetermined control operation,
The air conditioning control device includes a control device transmitting unit that modulates and transmits control data with an electromagnetic wave having a first frequency, and a hole formed in the wall surface of the air conditioning duct connected to the control device transmitting unit. Via the interrogator antenna which is positioned so as to protrude into the air conditioning duct and transmits the electromagnetic wave transmitted by the control device transmission unit into the air conditioning duct, and connected to the control device transmission unit. An external power supply unit that supplies power to operate the unit, a power transmission unit that is connected to the external power supply unit and transmits electromagnetic waves of the second frequency, and a wall surface of the air conditioning duct that is connected to the power transmission unit A power transmission antenna that is positioned so as to protrude into the air conditioning duct through the hole formed in the air conditioning duct, and that transmits the electromagnetic wave transmitted by the power transmission unit into the air conditioning duct;
The drive device has a response antenna positioned so as to protrude into the air conditioning duct via a hole formed in the wall surface of the air conditioning duct, and is connected to the response antenna, and has the first frequency. A driving device receiving unit that receives the control data conveyed by electromagnetic waves, an actuator that receives the control data received by the driving device receiving unit and performs a predetermined operation, and a hole formed in the wall surface of the air conditioning duct through section, positioned so as to protrude into the air-conditioning duct, wherein a power receiving antenna for receiving the second electromagnetic wave frequency sent out by the transmission antenna, and is connected to the power receiving antenna, said receiving antenna power storage for storing a rectifier unit to take out the DC power by rectifying the electromagnetic wave of the second frequency received by, the DC power taken out by the rectification part Provided with a door,
The drive device receiving unit and the actuator are driven by electric energy stored in the power storage unit.

The wireless communication system described above receives electromagnetic waves (radio waves) transmitted from the power transmission antenna of the air conditioning control device to the air conditioning duct, and receives the DC power by rectifying the received electromagnetic waves (radio waves). Then, the drive device receiving unit and the actuator are each driven by a non-power source using the DC power stored in the power storage unit.
Alternatively, the wireless communication system of the present invention measures an air conditioning duct made of a metal cylindrical body and a predetermined physical quantity, and modulates the measured physical quantity with an electromagnetic wave having a predetermined frequency and sends it out to the air conditioning duct. A wireless communication system having a device and an air conditioning control device for receiving the electromagnetic wave sent by the measuring device into the air conditioning duct,
The air conditioning control device is connected to the interrogation antenna, which is positioned so as to protrude into the air conditioning duct via a hole formed in the wall surface of the air conditioning duct, and is connected to the interrogation antenna by the measurement control device. A control device receiving unit that receives the physical quantity that is measured and modulated by the electromagnetic wave of the predetermined frequency and sent out;
The measuring device includes a response antenna positioned so as to protrude into the air conditioning duct through a hole formed in the wall surface of the air conditioning duct, and the measured predetermined physical quantity connected to the response antenna. A measuring device transmission unit that transmits electromagnetic waves of a predetermined frequency into the air conditioning duct, and a rectification unit that is connected to the response antenna and rectifies the electromagnetic waves of the predetermined frequency received by the response antenna and extracts DC power. And a power storage unit for storing the DC power taken out by the rectification unit,
The measuring device is driven by electric energy stored in the power storage unit.

  In the above wireless communication system, the response antenna of the measuring device receives the electromagnetic wave (radio wave) transmitted from the interrogation antenna of the air conditioning control device into the air conditioning duct, and rectifies the received electromagnetic wave (radio wave) to extract DC power. Then, the measuring device is driven by a non-power source using the DC power stored in the power storage unit. The environmental information measured by the measuring device is transmitted to the air conditioning duct via the response antenna, and taken into the air conditioning control device from the question antenna.

The wireless communication system of the present invention includes an air-conditioning duct made of a metal cylindrical body, an air-conditioning control device that sends control data modulated with electromagnetic waves of a predetermined frequency into the air-conditioning duct, and the air-conditioning control device includes the air-conditioning control device. A wireless communication system having a drive device that receives predetermined control data sent into an air conditioning duct and executes a predetermined control operation,
The air conditioning control device is connected to the interrogation antenna, which is positioned so as to protrude into the air conditioning duct via a hole made in the wall surface of the air conditioning duct, and is connected to the interrogation antenna. and a control device transmitting unit for sending the control data in the first wave of the plant allows constant wave number,
The drive device includes a response antenna positioned so as to protrude into the air conditioning duct through a hole formed in the wall surface of the air conditioning duct, and is connected to the response antenna so that the first electromagnetic wave A drive device receiver that receives the control data that has been conveyed, an actuator that receives the control data received by the drive device receiver, and performs a predetermined operation, and is connected to the response antenna and receives the response antenna. A rectifying unit that rectifies the first electromagnetic wave to extract DC power, and a power storage unit that stores the DC power extracted by the rectifying unit,
Wherein said drive receiving portion actuator is characterized in that is driven by electric energy stored in the power storage unit.
Furthermore, in addition to the above, in the wireless communication system of the present invention, the driving device is connected to a sensor that measures a predetermined physical quantity and the response antenna, and the predetermined physical quantity measured by the sensor is the second of the predetermined frequency. A driving device transmitting unit that transmits the electromagnetic wave into the air conditioning duct, and the air conditioning control device is connected to the interrogating antenna and transmits a physical quantity sent out from the driving device transmitting unit by the second electromagnetic wave. A control device receiving unit for receiving is further provided, wherein the driving device transmitting unit and the sensor are driven by electric energy stored in the power storage unit.

In the above wireless communication system, the response antenna of the driving device receives the electromagnetic wave (radio wave) transmitted from the interrogation antenna of the air conditioning control device into the air conditioning duct, and rectifies the received electromagnetic wave (radio wave) to extract DC power. Then, the drive device receiving unit and the actuator are each driven by a non-power source using the DC power stored in the power storage unit.
Each of the antennas may be a dipole antenna, a whip antenna, a sleeve antenna, a Yagi antenna, or a loop antenna.

Preferably, each of the antennas is a planar antenna that is attached to the inner wall surface of the air conditioning duct.
The above-described wireless communication system uses a directional planar antenna in particular, so that electromagnetic waves (radio waves) transmitted from the planar antenna into the air conditioning duct are efficiently provided to the reception side.
Preferably, at least one of the interrogating antenna and the response antenna is provided with a reflector that is positioned behind the air conditioning duct so that each antenna is desired and reflects the electromagnetic waves to the antennas.

Alternatively, at least one of the power transmission antenna and the power receiving antenna is provided with a reflector that is positioned behind the air conditioning duct and that desires each other's antenna to reflect the electromagnetic waves to the antennas.
In the above-described wireless communication system, electromagnetic waves (radio waves) radiated from the interrogation antenna and the power transmission antenna are reflected by, for example, a metal plate-like reflector (reflector) and efficiently provided to the response antenna and the power receiving antenna.

In the wireless communication system of the present invention, when the air conditioning duct has a bent portion, the interrogating antenna and the response antenna are arranged at predetermined positions in the air conditioning duct that sandwich the bent portion. Alternatively, the power transmitting antenna and the power receiving antenna are arranged at predetermined positions in the air conditioning duct that sandwich the bent portion.
In the above wireless communication system, electromagnetic waves (radio waves) radiated from the interrogation antenna and the power transmission antenna arrive at the bent portion of the air conditioning duct, and the electromagnetic waves (radio waves) reflected by the bent portion are the response antenna and the power receiving antenna. To reach.

  According to the wireless communication system of the present invention, the power supplied from the external power source is supplied from the power transmitting antenna positioned so as to protrude into the air conditioning duct through the hole formed in the wall surface of the air conditioning duct. While the air conditioning control device is equipped with a power transmission unit that transmits electromagnetic waves in the frequency range, the measuring device is a power receiving antenna positioned so as to protrude into the air conditioning duct through a hole made in the wall surface of the air conditioning duct Receives the electromagnetic wave in the second frequency range sent from the power transmission unit, rectifies by the rectification unit, takes out DC power, stores it in the power storage unit, and uses the stored DC power to measure the device (for example, sensor) and the driving device (For example, an actuator) or a measurement control device including these is driven. That is, the electromagnetic wave transmitted from the power transmission unit is transmitted with high efficiency to the measuring device with less leakage power while reflecting inside the metal air conditioning duct. Therefore, the measuring device can operate without an external power source.

  In addition, the wireless communication system of the present invention is an interrogation antenna positioned so that the air conditioning control device projects power supplied from an external power source into the air conditioning duct through a hole formed in the wall surface of the air conditioning duct. While the electromagnetic wave is transmitted from the power transmission unit, the measurement control device or the like transmits a response antenna positioned so as to protrude into the air conditioning duct through the hole formed in the wall surface of the air conditioning duct. The electromagnetic wave in the second frequency range is received, the electromagnetic wave is rectified by the rectifying unit, DC power is taken out and stored in the power storage unit, and the measuring device and the actuator are driven by the DC power stored in the power storage unit. Therefore, these measuring devices and the like can operate without an external power source. In addition, since the power required for the operation of these measurement control devices and the like is received via the response antenna for sending environmental information, the structure is simple. In particular, this method is preferable because it can be realized without changing the configuration of the air conditioning control device.

  Furthermore, the radio communication system of the present invention is configured using any of the dipole antenna, the whip antenna, the sleeve antenna, the Yagi antenna, or the loop antenna as each of the antennas, and thus can be realized with a simple structure. . Or since the radio | wireless communications system of this invention is provided using the antenna which has a planar antenna or a radiator, electromagnetic waves (radio waves) can be efficiently transmitted / received between an air-conditioning control apparatus and a measuring device. In particular, when the planar antenna is operated in a higher-order mode, the radiation angle becomes lower and the half width becomes narrower, so that the energy of the electromagnetic wave can be transmitted more efficiently.

  In the wireless communication system of the present invention, the electromagnetic wave (radio wave) radiated from the interrogation antenna and the power transmission antenna arrives at the bent portion of the air conditioning duct, and the electromagnetic wave (radio wave) reflected by the bent portion is the response antenna and the Since it is configured to reach the power receiving antenna, even if there is a bent portion in the air conditioning duct, there is a great practical effect that the measuring device can be operated without an external power source.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 11 are examples of embodiments for carrying out the invention. In the figure, the same reference numerals as those in FIG. 12 denote the same parts, and the basic configuration is the same as that of the conventional one shown in FIG. Therefore, the description thereof is omitted.
First, a radio communication system according to a first embodiment of the present invention will be described. This first embodiment eliminates the need for an external power source that drives a sensor that detects environmental information such as temperature and humidity in the vicinity of the actuator, for example.

  In FIG. 1, reference numeral 1 denotes an air conditioning control device that performs wireless transmission via the air conditioning duct 2. This air conditioning control device 1 is detected by a sensor 11 provided in a measurement control device 10 to be described later, and is modulated in an air conditioning duct 2 by an electromagnetic wave (radio wave) having a first frequency (for example, 2.4 GHz band) and conveyed. Environment information (temperature, humidity, etc.) is guided to the outside of the air conditioning duct 2 via the interrogating antenna 3 provided so as to protrude into the air conditioning duct 2 and is received by the actuator 12 described later. The control unit transmitting unit that modulates and transmits control data with electromagnetic waves (radio waves) of the first frequency via 3 and the transmitting / receiving unit 4 that plays the role of the control unit receiving unit that receives the physical quantity transmitted by the measurement control unit 10 It is configured with. The transmission / reception unit 4 is connected to a control unit 5 that controls the air conditioning control device 1.

For example, the air conditioning control device 1 receives environmental information from the sensor 11 to maintain environmental conditions such as a temperature setting value and a humidity setting value input from an input unit (not shown) by the user, and transmits a drive command to the actuator 12. To play a role. Incidentally, an external power source 6 for driving the air conditioning control device 1 including the transmission / reception unit 4 and the control unit 5 is connected to the air conditioning control device 1.
In addition, the air conditioning control device 1 receives power supplied from the external power supply 6, and transmits an electromagnetic wave (radio wave) having a second frequency (for example, 800 MHz band) different from the first frequency in the air conditioning duct 2. 20 is provided with a power transmission unit 21 that performs transmission using 20. The power transmission unit 21 sends out a carrier wave having a predetermined frequency of, for example, about several W to several tens W into the air conditioning duct 2 by the power transmission antenna 20.

  On the other hand, the measurement control device 10 includes a sensor 11 that constitutes a measurement device that detects environmental information (temperature, humidity, etc.) as a physical quantity in the vicinity of the measurement control device 10, and the environmental information detected by the sensor 11 1 is transmitted to the air conditioning duct 2 by the measuring device transmitter 16 (hereinafter simply referred to as a transmitter 16) that modulates the electromagnetic wave with the first frequency electromagnetic wave and transmits the environmental information transmitted by the transmitter 16. The response antenna 13 is provided. The response antenna 13 is provided so as to protrude into the air conditioning duct 2.

  The measurement control device 10 includes a power receiving antenna 30 that is provided so as to protrude into the air conditioning duct 2 and receives an electromagnetic wave having a second frequency sent from the power transmission antenna 20 of the air conditioning control device 1. The electromagnetic wave of the second frequency captured by the power receiving antenna 30 is given to the rectifying unit 31 that rectifies the energy of the electromagnetic wave and extracts it as DC power. The rectifier 31 is applied with a rectifier circuit such as a bridge rectifier circuit or a half-wave rectifier circuit using a power semiconductor device such as a diode. Then, the DC power extracted by the rectifying unit 31 is guided to the power storage unit 32 that stores the DC power. Incidentally, the power storage unit 32 is configured by a chargeable / dischargeable device such as an electric double layer capacitor or a secondary battery, and serves as a power supply unit that supplies operating power to the sensor 11 and the transmission unit 16.

  In addition, the measurement control device 10 includes an actuator 12 serving as a main body of a drive device that is driven in response to a drive command issued from the control unit 5 of the air conditioning control device 1. The actuator 12 is connected to a drive device receiver 17 (hereinafter simply referred to as a receiver 17) that receives a drive command sent from the air conditioning controller 1 into the air conditioning duct 2 via the response antenna 13. The actuator 12 and the receiving unit 17 are driven by DC power stored in the power storage unit 32 described above.

Incidentally, the actuator 12 and the receiving unit 17 included in the measurement control device 10 may be driven by a separate power source.
The interrogating antenna 3, the power transmitting antenna 20, the response antenna 13, and the power receiving antenna 30 described above may be a dipole antenna having an antenna length that is ½ wavelength of the frequency transmitted and received by each antenna. However, the antenna length and the antenna type of each antenna are not limited to a half-wave dipole antenna, but a single-wavelength dipole antenna, whip antenna, sleeve antenna or loop antenna, a planar antenna, a Yagi antenna, etc., which will be described later It doesn't matter. In other words, the form or the like is not limited as long as it transmits and receives radio waves of a predetermined frequency into the air conditioning duct 2.

  Alternatively, although not shown in the drawing, each antenna has a predetermined position in the back direction of each antenna with respect to the direction in which the response antenna 13 is desired from the interrogation antenna 3 and the direction from the power transmission antenna 20 toward the power reception antenna 30. It is preferable that a reflector constituted by a metal flat plate or the like is provided at a predetermined position in the rear direction, and an electromagnetic wave transmitted from each antenna is reflected by this reflector. Although details will be described later, this reflector plays a role of giving predetermined directivity to the interrogating antenna 3, the power transmitting antenna 20, the response antenna 13, and the power receiving antenna 30.

  For example, if the radio wave radiated from the interrogating antenna 3 into the air conditioning duct 2 is a direct wave and a part of the direct wave is reflected by the reflector, the direct wave and the reflected wave have the same phase. Combined and radiated in the direction of the response antenna 13. Similarly, the response antenna 13 also combines the direct wave directly reaching the response antenna 13 from the interrogation antenna 3 and the reflected wave reflected by the reflector positioned behind the response antenna 13 by the response antenna 13 to receive power ( Receiving electric field intensity).

  Note that the distance between the interrogator antenna 3 and the reflector located in the rear direction or the distance between the response antenna 13 and the reflector located in the rear direction is such that the direct wave and the reflected wave are synthesized in phase with each antenna. Just place it. That is, the distance between the antennas 3 and 13 and the reflector is λ / 4, 3λ / 4, 5λ / 4 (2n−1) λ / 4 (where λ is the wavelength of electromagnetic waves to be transmitted and received. However, it may be positioned such that n ≧ 0.

In addition, the reflector positioned behind each antenna is a mesh-like metal plate having eyes smaller than the wavelength λ of the electromagnetic wave reaching the reflector in order to reduce the air resistance in the air conditioning duct 2. Is preferred.
In the wireless communication system according to the first embodiment of the present invention, which is schematically configured as described above, the power transmission unit 21 of the air conditioning control device 1 transmits, for example, an 800 MHz band electromagnetic wave in the air conditioning duct 2 by the power transmission antenna 20. To send. This electromagnetic wave reaches the power receiving antenna 30 of the measurement control device 10 while reflecting the inner wall surface of the metal air conditioning duct 2 or directly.

On the other hand, the measurement control device 10 converts the energy of the 800 MHz band electromagnetic wave received by the power receiving antenna 30 into DC power by the rectifying unit 31 and stores the extracted DC power in the power storage unit 32. The DC power stored in the power storage unit 32 is released as energy for driving the sensor 11 and the transmission / reception unit 14.
When the air conditioning duct 2 has a square shape, for example, when it is 300 mm × 300 mm, the cutoff frequency is 500 MHz. Therefore, the electromagnetic waves in the 800 MHz band and the 2.4 GHz band can be reliably transmitted by the air conditioning duct 2. it can.

  Thus, in the wireless communication system according to the first embodiment of the present invention, the air conditioning control device 1 transmits and receives environmental information from the power transmission antenna 20 positioned so as to project the power supplied from the external power supply 6 into the air conditioning duct 2. In addition to the power transmission unit 21 that sends out an electromagnetic wave in the 800 MHz band, for example, which is different from the electromagnetic wave having a frequency (for example, 2.4 GHz band), the measurement control device 10 projects the electromagnetic wave in the 800 MHz band into the air conditioning duct 2. The power receiving antenna 30 is positioned so as to be rectified by the rectifying unit 31 and DC power is taken out and stored in the power storage unit 32 and used as a power source for driving the measurement control device 10. In addition, the electromagnetic wave transmitted from the power transmission unit 21 can be transmitted to the measurement control device 10 with less leakage power, that is, with high efficiency while reflecting the inside of the metal air conditioning duct 2. For this reason, the measurement control apparatus 10 can operate without an external power source required for measurement.

Next, a radio communication system according to a second embodiment of the present invention will be described with reference to a schematic configuration diagram shown in FIG. This second embodiment differs from the first embodiment described above in that the power transmission antenna 20 and the power transmission unit 21 of the air conditioning control device 1 are omitted, the power reception antenna 30 of the measurement control device 10 is omitted, and a response antenna. 13 is that the electromagnetic wave received by 13 is guided to the rectifying unit 31.
A wireless communication system according to the second embodiment of the present invention having such characteristics will be described with reference to FIG. In the figure, the same reference numerals as those in FIGS. 1 and 12 denote the same components, and the basic configuration is the same as that of the first embodiment and the conventional one, and the description thereof is omitted.

  In the second embodiment, an electromagnetic wave (radio wave) having a predetermined frequency (for example, 2.4 GHz band) transmitted from the air conditioning control device 1 to the air conditioning duct 2 via the interrogating antenna 3 provided in the air conditioning duct 2 is used. The response antenna 13 of the measurement control device 10 receives the received electromagnetic wave to the rectifying unit 31, extracts the energy as DC power, and stores it in the power storage unit 32. The DC power stored in the power storage unit 32 is used as a power source for driving the sensor 11 and the transmission unit 16. Moreover, you may apply the direct-current power stored in the electrical storage part 32 as a power supply which drives the actuator 12 and the receiving part 17, respectively.

  Thus, the radio communication system according to the second embodiment of the present invention uses the electromagnetic wave of the frequency (for example, 2.4 GHz band) for transmitting and receiving between the air conditioning control device 1 and the measurement control device 10. The measurement control device 10 receives the electromagnetic wave of this frequency with the response antenna 13 positioned so as to protrude into the air conditioning duct 2, and the rectifying unit receives the received electromagnetic wave. The power is rectified by 31 and stored in the power storage unit 32 and used as a power source for driving the measurement control device 10. Further, the electromagnetic wave transmitted from the transmission / reception unit 4 of the air conditioning control device 1 can be transmitted to the measurement control device 10 with less leakage power, that is, with high efficiency while being reflected inside the metal air conditioning duct 2. Therefore, the measurement control device 10 can be operated without an external power source. In particular, this method has a simple structure because the response antenna 13 receives power for operating the measurement control device 10. Furthermore, the wireless communication system according to the second embodiment of the present invention is more preferable because it can be realized without changing the configuration of the air conditioning control device 1.

By the way, the inventors have conducted simulations and confirmed the effects of the wireless communication system of the present invention that can obtain such excellent effects. This simulation is a transmission simulation using the ray tracing method, and the received power at the receiving point was compared for each of the following five different cases.
<1> Comparison of received power between a straight duct having a square cross section and free space <2> Comparison of received power between a straight duct having a circular cross section and free space <3> Duct having a bent portion Comparison of received power between inside and free space <4> Comparison of received power in linear duct when using basic mode planar antenna and higher-order mode planar antenna <5> Linear duct with or without reflector (reflector) First, the received power comparison between the straight duct having a square cross section and the free space was performed under the following conditions.
(A) Air conditioning duct Cross section: square shape of 300 mm x 300 mm Material: Steel (B) Transmitting antenna and receiving antenna: 1/2 disposed at the center of the cross section of the air conditioning duct at a position extending perpendicular to the cross section direction 2 wavelength dipole antenna (C) Distance between transmitting antenna and receiving antenna: 1 m to 40 m every 1 m (D) Frequency: 2450 MHz
(E) Transmission output: 0 dBm
(F) Number of electromagnetic waves reflected in the air-conditioning duct between the transmitting antenna and the receiving antenna: 5 times or less (G) Comparison object: received power in free space and received power in the duct Is the power transmission antenna 20, the response antenna 13 or the interrogation antenna 3 that sends out electromagnetic waves into the air conditioning duct 2, and the reception antenna is the power reception antenna 30, the interrogation antenna 3 or the response antenna 13 that receives the electromagnetic waves propagated by the air conditioning duct 2. is there.

As a result, as shown by the broken line in FIG. 3, the received power in free space is -42 dBm at a point where the distance from the transmitting antenna to the receiving antenna is 1 m, -55 dBm at a point where the distance is 10 m, and a point where the distance is 20 m. It was -65 dBm at a point of -62 dBm, a distance of 30 m, and -68 dBm at a point of 40 m in distance.
On the other hand, the received power in the air conditioning duct is -23 dBm at a point of 1 m from the transmitting antenna to the receiving antenna, -51 dBm at a point of 10 m, and a distance of 20 m as shown by the solid line in FIG. It was -52 dBm at the point, -58 dBm at the point where the distance was 30 m, and -59 dBm at the point where the distance was 40 m.

  As can be seen from the simulation results, the reception intensity of the electromagnetic wave propagating in the air conditioning duct (the electric field intensity at the reception point) is about 10 dB higher than the electromagnetic wave propagating in the free space. This is because electromagnetic waves in the free space diffuse while radiating in the free space, whereas electromagnetic waves radiated from the transmitting antenna in the air conditioning duct 2 are repeatedly reflected on the inner wall surface of the air conditioning duct 2. By reaching the receiving antenna.

In addition, the inventors performed a simulation on the comparison of received power between a straight duct having a circular cross section and free space. This simulation uses the air-conditioning duct 2 having a true circular cross-sectional shape having a diameter of 300 mm, and the other conditions are the same as described above.
As a result, as shown by the solid line in FIG. 4, the received power in the air conditioning duct is -5 dBm at a distance of 1 m from the transmitting antenna to the receiving antenna, -25 dBm at a distance of 10 m, and a distance of 20 m. -32 dBm, -38 dBm at a distance of 30 m, and -43 dBm at a distance of 40 m.

As shown in the simulation results, it was confirmed that the electric field strength at the reception point of the electromagnetic wave propagating in the air conditioning duct was about 20 dB higher than the electromagnetic wave propagating in free space. This is because the electromagnetic wave reflected by the inner wall surface having a circular shape efficiently reaches the receiving antenna as compared with the rectangular air conditioning duct.
Next, as shown in FIG. 5, the inventors have confirmed the transmission characteristics of the air conditioning duct having a bent portion and the free space by comparing the transmission power with a simulation. This simulation was performed under the following conditions.
(A) Air-conditioning duct Cross section: square shape of 300mm x 300mm Material: Steel Bending angle: 90 °
Bending radius: 500mm
Bending portion outer radius: 800mm
(B) Transmitting antenna and receiving antenna: 1/2 wavelength dipole antenna disposed at a position extending perpendicularly to the cross-sectional direction at the center of the cross section of the air conditioning duct (C) Distance between transmitting antenna and bent portion: 5 m Distance between fixed (D) bent portion and receiving antenna: 1 m to 10 m (i.e., 6 m to 15 m from the transmitting antenna) (Fig. 6)
(E) Frequency: 2450MHz
(F) Transmission output: 0dBm
(G) Number of electromagnetic waves reflected in the air-conditioning duct from the transmitting antenna to the receiving antenna: 5 times or less (H) Comparison target: received power in free space and received power in the duct As indicated by the solid line, the received power in the air conditioning duct was -40 dBm at a distance of 6 m from the transmitting antenna to the receiving antenna, -37 dBm at a distance of 10 m, and -49 dBm at a distance of 15 m. It was.

As shown in the simulation results, it was verified that the electric field strength at the reception point of the electromagnetic wave propagating in the air conditioning duct was higher by 10 dB or more than the electromagnetic wave propagating in free space. This is because the inner wall surface of the bent portion of the air conditioning duct acts like a concave mirror, and the received electric field strength is higher than that of a straight pipe type air conditioning duct having no bent portion.
Furthermore, the inventors simulated changes in received power when a planar antenna was installed on the inner wall surface of the air conditioning duct instead of the half-wave dipole antenna used in the above-described simulation. This planar antenna uses a basic mode planar antenna having a directivity of 9 dBi having directivity shown in FIG. 8 and a high-order mode planar antenna having a gain of 6 dBi having directivity shown in FIG. It was.
(A) Air-conditioning duct Cross section: square shape of 300 mm x 300 mm Material: Steel (B) Transmitting antenna and receiving antenna: Both antennas apply basic mode planar antenna and higher-order mode antenna (C) Transmission antenna and receiving antenna Distance: 1m to 20m every 1m (D) Frequency: 2450MHz
(E) Transmission output: 0 dBm
(F) Number of electromagnetic waves reflected in the air conditioning duct from the transmitting antenna to the receiving antenna: 5 times or less (G) Comparison object: received power in the basic mode planar antenna and the higher mode planar antenna As shown by the dashed line 10, the reception power when the basic mode antenna is used for the transmission antenna and the reception antenna is −32 dBm at a point where the distance from the transmission antenna to the reception antenna is 1 m, and −67 dBm at a point where the distance is 5 m. The distance was -86 dBm at a point of 10 m, -77 dBm at a point of 15 m, and -77 dBm at a point of 20 m.

On the other hand, the received power when the higher-order mode antenna is used for the transmission antenna and the reception antenna is -20 dBm at a point where the distance from the transmission antenna to the reception antenna is 1 m, -41 dBm at a point where the distance is 5 m, and the distance is 10 m. It was -59 dBm at the point, -58 dBm at the point where the distance was 15 m, and -58 dBm at the point where the distance was 20 m.
As shown in the simulation results, it can be confirmed that the higher-order mode antenna having a conical directional characteristic increases the reception power at the reception point by about 20 dB as compared with the basic mode antenna.

Since this kind of planar antenna can be attached to the inner wall surface of the air conditioning duct, it is preferable without increasing the flow path resistance of the fluid flowing in the air conditioning duct.
Next, the inventors performed a transmission simulation when a reflector was provided behind the antenna. The reflector of the transmission antenna is installed so as to be located behind the transmission antenna in the direction from the transmission antenna to the reception antenna. Similarly, the reflecting plate of the receiving antenna is installed so as to be positioned behind the receiving antenna in the direction from the receiving antenna to the transmitting antenna.

The inventors of the present invention have confirmed the transmission characteristics of the received power in the linear duct with or without such a reflector (reflector) by simulation. This simulation was performed under the following conditions.
(A) Air conditioning duct Cross section: square shape of 300 mm x 300 mm Material: Steel (B) Transmitting antenna and receiving antenna: 1/2 disposed at the center of the cross section of the air conditioning duct at a position extending perpendicular to the cross section direction Two-wavelength dipole antenna (C) reflector: A steel plate is installed at a position 90 mm (3/4 wavelength) away from each antenna behind the transmitting antenna and the receiving antenna. (D) Transmitting antenna and receiving antenna Distance: 1m to 40m every 1m (E) Frequency: 2450MHz
(F) Transmission output: 0dBm
(G) Number of electromagnetic waves reflected in the air-conditioning duct from the transmitting antenna to the receiving antenna: 5 times or less (H) Comparison object: When there is a receiving power and a reflecting plate when there is no reflecting plate in the duct As a result, the reception power at the reception point when there is no reflector is the same as the reception power in the air conditioning duct as shown by the broken line in FIG. 11, but when a reflector is provided, As indicated by the solid line, the received power in the air conditioning duct is -20 dBm at a distance of 1 m from the transmitting antenna to the receiving antenna, -42 dBm at a distance of 10 m, -43 dBm at a distance of 20 m, and the distance is It was -49 dBm at a point of 30 m and -51 dBm at a point of 40 m in distance.

  Thus, when the reflector is provided behind each of the transmitting antenna and the receiving antenna, the electric field strength at the reception point of the electromagnetic wave propagating in the air conditioning duct is about 10 dB higher than the electromagnetic wave propagating in the free space by the reflecting plate. I understand that This is because, in the case of a transmitting antenna, a direct wave radiated from the transmitting antenna and a reflected wave in which a part of the direct wave is reflected by the reflector are combined in the same phase and radiated in the direction of the receiving antenna. . Similarly, the reception antenna also has a strong reception power by combining the direct wave directly coming to the reception antenna and the reflected wave reflected by the reflector in the same phase by the reception antenna.

The distance between the transmitting antenna and the reflecting plate or the distance between the receiving antenna and the reflecting plate may be such that the direct wave and the reflected wave are synthesized in the same phase in each antenna. That is, the distance between each antenna and the reflector is λ / 4, 3λ / 4, 5λ / 4 (2n−1) λ / 4 (where n (Position of ≧ 0)
As described above, the wireless communication system according to the present invention is practically great in that it can provide a wireless communication system that does not require wiring and batteries for driving the sensor by using the air conditioning duct 2 as an electromagnetic wave propagation path. It has been confirmed that

  The wireless communication system of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

1 is a block diagram showing a schematic configuration of a wireless communication system according to a first embodiment of the present invention. The block diagram which shows schematic structure of the radio | wireless communications system which concerns on 2nd embodiment of this invention. The graph which shows the received power simulation result in the free space and square duct using the ray tracing method. The graph which shows the received power simulation result in the free space and circular duct using the ray tracing method. The perspective view which shows the external appearance of the duct which has a bending part. The top view which shows the external appearance of the duct which has a bending part. The graph which shows the received power simulation result in the free space and the duct which has a bending part using the ray tracing method. The graph which shows the directional characteristic of a basic mode planar antenna. The graph which shows the directional characteristic of a high-order mode planar antenna. The graph which shows the received power simulation result in the duct of a fundamental mode planar antenna and a higher-order mode planar antenna using the ray tracing method. The graph which shows the result of having simulated the received power by the presence or absence of a reflecting plate using the ray tracing method. The block diagram which shows schematic structure of the conventional radio | wireless communications system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air-conditioning control apparatus 2 Air-conditioning duct 3 Question antenna 4 Transmission / reception part 5 Control part 6 External power supply 10 Measurement control apparatus 11 Sensor 12 Actuator 13 Response antenna 14 Transmission part 20 Power transmission antenna 21 Power transmission part 30 Power reception antenna 31 Rectification part 32 Power storage part

Claims (10)

An air-conditioning duct made of a metal tubular body;
A measuring device that measures a predetermined physical quantity, modulates the measured physical quantity with an electromagnetic wave of a predetermined frequency, and transmits it in the air conditioning duct;
A wireless communication system having an air conditioning control device that receives the electromagnetic wave transmitted by the measuring device into the air conditioning duct and receives the physical quantity conveyed by the electromagnetic wave,
The air-conditioning control device is positioned so as to protrude into the air-conditioning duct through a hole formed in the wall surface of the air-conditioning duct, and the electromagnetic wave transmitted by the measuring device with the electromagnetic wave having the first frequency. Receive the question antenna and the
A controller receiving unit connected to the interrogation antenna and receiving the physical quantity carried by the electromagnetic wave of the first frequency;
An external power supply unit connected to the control device receiving unit and supplying power for operating the control device receiving unit;
A power transmission unit connected to the external power supply unit and transmitting an electromagnetic wave of the second frequency,
An electromagnetic wave connected to the power transmission unit and positioned so as to protrude into the air conditioning duct through a hole formed in the wall surface of the air conditioning duct and transmits the electromagnetic wave transmitted by the power transmission unit in the air conditioning duct. And a power transmission antenna
The measuring device is a measuring device transmitter that modulates and transmits the measured physical quantity with an electromagnetic wave of the first frequency,
The electromagnetic waves transmitted from the measuring device transmitter are connected to the measuring device transmitter and positioned so as to protrude into the air conditioning duct through holes formed in the wall surface of the air conditioning duct. A response antenna that feeds into the duct;
Through a hole that is drilled in the wall of the air-conditioning duct, a power receiving antenna is positioned so as to project into the air conditioning duct, receiving said second electromagnetic wave frequency sent out by the transmission antenna,
This is connected to the power receiving antenna, a rectifier unit to take out the DC power electromagnetic waves of the second frequency of the power receiving antenna has received rectified to,
A power storage unit that stores the DC power extracted by the rectification unit;
The wireless communication system, wherein the measuring device is driven by DC power stored in the power storage unit. An air-conditioning duct made of a metal tubular body;
An air conditioning control device for sending control data modulated by electromagnetic waves of a predetermined frequency into the air conditioning duct;
A wireless communication system having a drive device that receives predetermined control data sent into the air conditioning duct by the air conditioning control device and executes a predetermined control operation,
The air conditioning control device is a control device transmitter that modulates and transmits control data with an electromagnetic wave of a first frequency, and
The electromagnetic wave transmitted from the control device transmission section is connected to the control device transmission section and is positioned so as to protrude into the air conditioning duct through a hole formed in the wall surface of the air conditioning duct. A question antenna to be sent into the duct,
An external power supply connected to the control device transmitter and supplying power for operating the control device transmitter;
A power transmission unit connected to the external power supply unit and transmitting an electromagnetic wave of the second frequency,
An electromagnetic wave connected to the power transmission unit and positioned so as to protrude into the air conditioning duct through a hole formed in the wall surface of the air conditioning duct and transmits the electromagnetic wave transmitted by the power transmission unit in the air conditioning duct. And a power transmission antenna
The drive device has a response antenna positioned so as to protrude into the air conditioning duct through a hole made in the wall surface of the air conditioning duct;
A drive receiving unit connected to the response antenna and receiving the control data carried by the electromagnetic wave of the first frequency;
An actuator that receives the control data received by the driving device receiver and executes a predetermined operation;
Through a hole that is drilled in the wall of the air-conditioning duct, a power receiving antenna is positioned so as to project into the air conditioning duct, receiving said second electromagnetic wave frequency sent out by the transmission antenna,
A rectifying unit connected to the power receiving antenna and rectifying the electromagnetic wave of the second frequency received by the power receiving antenna to extract DC power;
A power storage unit that stores the DC power extracted by the rectification unit;
The wireless communication system, wherein the driving device receiving unit and the actuator are driven by electrical energy stored in the power storage unit. The at least one of the power transmitting antenna and the power receiving antenna includes a reflector that is positioned behind the air conditioning duct so as to desire each other's antenna and reflects the electromagnetic wave to each antenna. Item 3. The wireless communication system according to Item 1 or 2 . The wireless communication system according to claim 1 or 2 ,
When the air-conditioning duct has a bent portion, the power transmission antenna and the power receiving antenna are arranged at predetermined positions in the air-conditioning duct that sandwich the bent portion. An air-conditioning duct made of a metal tubular body;
An air conditioning control device for sending control data modulated by electromagnetic waves of a predetermined frequency into the air conditioning duct;
A wireless communication system having a drive device that receives predetermined control data sent into the air conditioning duct by the air conditioning control device and executes a predetermined control operation,
The air conditioning control device includes a question antenna positioned so as to protrude into the air conditioning duct through a hole made in the wall surface of the air conditioning duct,
Connected to this question antenna, and a control device transmitting unit for sending the control data in the first wave of the plant allows constant wave number in said air conditioning duct,
The drive device has a response antenna positioned so as to protrude into the air conditioning duct through a hole made in the wall surface of the air conditioning duct;
A driving device receiver connected to the response antenna and receiving the control data carried by the first electromagnetic wave;
An actuator that receives the control data received by the driving device receiver and executes a predetermined operation;
A rectifier connected to the response antenna and rectifying the first electromagnetic wave received by the response antenna to extract DC power;
A power storage unit that stores the DC power extracted by the rectification unit;
It said actuator and said drive receiving portion, a radio communication system, characterized in that it is driven by the electric energy stored in the power storage unit. The wireless communication system according to claim 5, wherein
The drive device is connected to the sensor for measuring a predetermined physical quantity, and the drive device transmission is connected to the response antenna, and transmits the predetermined physical quantity measured by the sensor into the air conditioning duct by the second electromagnetic wave having the predetermined frequency. And further comprising
The air conditioning control device is connected to the question antenna, further comprising a controller receiving section for receiving the physical quantity issued to Ri feed Te in the second electromagnetic wave from the drive transmission unit,
The wireless communication system, wherein the driving device transmission unit and the sensor are driven by electrical energy stored in the power storage unit. Wherein each antenna, each dipole antenna, a whip antenna, a wireless communication system according to any one of claims 1 to 6, wherein the sleeve antenna is either a Yagi antenna or loop antenna. Wherein each antenna, a radio communication system according to any one of claims 1 to 6, characterized in that a flat antenna at least one of which is affixed to the inner wall surface of the air-conditioning duct. The at least one of the interrogation antenna and the response antenna includes a reflector that is positioned behind the air conditioning duct and that desires each other's antenna to reflect the electromagnetic waves to the antennas. Item 10. A wireless communication system according to any one of Items 1 to 8 . A wireless communication system according to any one of claims 1 to 9 ,
When the air conditioning duct has a bent portion, the interrogating antenna and the response antenna are arranged at predetermined positions in the air conditioning duct that sandwich the bent portion.