JPH10107711A - Method and device for transmitting/receiving indoor environmental state - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain stable signal transmission even when an obstacle such as a duct of an air-conditioner system is in existence between a transmitter and a receiver by extending an installation available area of the transmitter and the receiver. SOLUTION: A receiver 3 and a transmitter 4 are installed in a ceiling internal space 1-2. An nondirectional antenna is adopted for a transmission antenna 4-1. A reception antenna 3-1 has a directivity and its direction is directed in a direction of a floor face. In a radio wave sent form the transmission antenna 4-1, a direct wave is attenuated by an H steel 10 in a beam 9 and a radio wave propagated in a direction of a floor 11 is reflected in reinforcement bars 12 or the like in the inside of the floor and reaches the reception antenna 3-1. Since the directivity of the reception antenna 3-1 is directed in the direction of the floor face, the antenna 3-1 has a higher gain in the reception of the reflected wave arrived from the floor face than the attenuated direct wave arrived in the lateral direction, then the effect of interference is reduced and production of a dead band is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for transmitting and receiving indoor environment conditions from a transmitter installed in the same room (including a ceiling and a space inside the ceiling) to a receiver using radio waves. Things.

[0002]

2. Description of the Related Art Conventionally, as this kind of indoor environment state transmitting / receiving apparatus, there is a "temperature detecting apparatus" disclosed in Japanese Utility Model Laid-Open Publication No. 3-124141. FIG. 12 is a block diagram showing this temperature detecting device. In the figure, 21 is a transmitter, 22 is a receiving antenna, 23 is a coaxial cable, 24 is a receiver, 25 is a temperature controller, and 26 is an air conditioner. The transmitter 21 includes a temperature sensor 21-1 and a transmission circuit 21-2.
And a transmission antenna 21-3.

[0003] As shown in FIG.
It is mounted on the wall surface of the indoor interior space (living room) 27-1. The living room 27-1 and the ceiling interior space 27-2 are the ceiling material 2
It is partitioned by 7-3. The receiving antenna 22, the coaxial cable 23, the receiver 24, the temperature controller 25, and the air conditioner 26 are installed in the ceiling internal space 27-2. In the transmitter 21, the temperature sensor 21-1 detects the room temperature and sends it to the transmission circuit 21-2 as a room temperature signal. The transmission circuit 21-2 converts the room temperature signal from the temperature sensor 21-1 into an ultrashort-wave modulated signal and sends it to the transmission antenna 21-3. The transmission antenna 21-3 radiates the ultrashort-wave modulated signal from the transmission circuit 21-2.

[0004] The ultrashort-wave modulated signal radiated from the transmitter 21 is received by the receiving antenna 22 through a ceiling made of a radio wave transmitting material, and passed through the coaxial cable 23 to the receiver 24.
Sent to The receiver 24 demodulates the received ultrahigh frequency modulation signal and restores the room temperature signal detected by the temperature sensor 21-1. The restored room temperature signal is sent to the temperature controller 2
5 to the air conditioner 26. Thereby, the air conditioner 26 controls the air volume or temperature of the intake air from the suction port 27, and from the outlet 29 through the duct 28, the living room 27-1.
To perform constant value control of the room temperature.

Here, the receiving antenna 22 is a loop antenna. The size of the receiving antenna 22 is λ
Is the wavelength of the received radio wave, "loop radius r <λ / 1
2 ”. This corresponds to a so-called “small loop antenna” in which the circumference is shorter than the wavelength (2rπ <λ). In the case of a small loop antenna, FIG.
As shown in (a), it has a maximum radiation direction in the loop plane. That is, the minute loop antenna has directivity. In this case, the directivity of the small loop antenna is s
It is represented by inθ. Hereinafter, the maximum radiation direction in the loop plane will be referred to as “direction of directivity”. In FIG. 13, since the loop of the receiving antenna 22 is placed on the ceiling surface,
The direction along the ceiling surface can be interpreted as the direction of directivity.

[0006] In this temperature detecting device, since the ultrashort wave is used, the loop radius r is reduced, and the receiving antenna 22
Are reduced in size. Further, since the receiving antenna 22 and the receiver 24 are connected by the coaxial cable 23, the receiving sensitivity of the radio wave from the transmitter 21 is maximized, and the receiving antenna 22 is isolated from the metal material of the building that reduces the receiving sensitivity. Thus, the installation position and orientation of the receiving antenna 22 can be easily selected. Further, since the receiving antenna 22 has directivity, a stable operation can be obtained in an environment where there are many jamming waves.

For reference, FIG. 14B shows directivity when the circumference of the loop antenna is equal to the wavelength of the received radio wave, and FIG. 14C shows that the circumference of the loop antenna is equal to the wavelength of the received radio wave. The directivity when there is a reflector is shown. FIG.
In (b), the directivity of the loop antenna 22 ′ is 2
cos (0.27πcosθ) (Reference:
"Antenna system and radio wave propagation", p. 72, p. 183, CQ Publishing Co., Ltd.). In FIG. 14C, it is considered that one side of the reflector 30 should be at least three times the radius r of the loop antenna 22 '(reference: "Antenna Engineering Handbook", Ohmsha).

[0008]

However, in such a conventional temperature detecting device, the transmitter 2 shown in FIG.
As is clear from the positional relationship between the antenna 1 and the receiving antenna 22, the transmitter 21 and the receiving antenna 22 are arranged in a position where they can be seen from each other, that is, in a position where there is no obstacle to radio waves, and the direct wave from the transmitter 21 is received. System. In this case, an area (dead zone) where the sensitivity is extremely reduced occurs due to the interference between the direct wave and the reflected wave from the building wall.

FIG. 15A shows an electric field strength characteristic (simulation) when only a reflected wave is received, and FIGS.
(D) shows an electric field strength characteristic (simulation) when a direct wave and a reflected wave are received. Reference strength (0d
The part cut off B) becomes a dead zone. The reference strength (0
dB) is the electric field strength at a point of 10 m in FIG. FIG. 15B shows a case where both the direct wave and the reflected wave can be transmitted and received without the influence of the radio wave attenuator. However, even if the distance is large, the amplitudes of the two waves become closer and the influence of the phase becomes remarkable. In this case, 0 dB is cut off 10 m before, and a dead zone occurs. FIGS. 15C and 15D show that, when the attenuation factor due to metal is β, β = 0.5,
In the case where there is an obstacle where β = 0.2, 0 dB is locally cut at a short distance, resulting in a dead zone.

As described above, when the system is used to receive the direct wave from the transmitter, a dead zone is generated due to the interference between the direct wave and the reflected wave from the building wall, and the area where the transmitter can be installed is limited. Will be done. Originally, such a wireless detection device is suitable for construction in an existing building where wiring work is difficult. However, in the related art, the installation locations of the transmitter and the receiving antenna are limited, so that the applicable form of the building is limited.

[0011] Incidentally, there is a demand for avoiding the installation of the transmitter on the indoor wall surface because it is not preferable in terms of aesthetic appearance. In response to this request, it is conceivable to install the transmitter 21 in the ceiling interior space 27-2 in FIG. However, there are metal air-conditioning ducts or beams or columns containing a reinforced steel frame in the ceiling of most buildings, which hinders radio wave propagation. If the transmitter 21 and the receiving antenna 22 are to be installed at a position other than the dead zone while avoiding the above, the installation position is limited to an extremely narrow range, and there are very few buildings to which this can be applied.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to expand a region where a transmitter and a receiver can be installed, and to provide a space between a transmitter and a receiver. A method and apparatus for transmitting and receiving indoor environmental conditions that enables stable signal transmission even when obstacles such as air-conditioning ducts, beams, and columns are present in the building, and enables the transmitter to be installed in the ceiling interior space in various buildings. To provide.

[0013]

In order to achieve such an object, a first invention (an invention according to claim 1) provides a transmitting antenna and a receiving antenna in the same room of a building in which a material that reflects radio waves is disposed. An antenna is arranged, at least one of the transmitting antenna and the receiving antenna is an antenna having directivity, the transmitting antenna is installed in a direction without directivity of the receiving antenna, and the receiving antenna is installed in a direction without directivity of the transmitting antenna. The environmental condition signal is converted into a radio signal and transmitted from the transmitting antenna, and the radio signal transmitted from the transmitting antenna and reflected by the material that reflects the radio wave in the building is received by the receiving antenna. is there.
According to the present invention, when the receiving antenna is an antenna having directivity and the transmitting antenna is an omnidirectional antenna, the transmitting antenna is installed in a direction without directivity of the receiving antenna, and the indoor environment state signal is a radio signal. And radiated from the transmitting antenna. The radio signal radiated from the transmitting antenna is reflected by a material that reflects radio waves in the building, and is received by the receiving antenna.

The second invention (the invention according to claim 2) is the first invention.
In the present invention, the transmitting antenna and the receiving antenna are installed on the ceiling in the same room, and the direction of the directivity of the antenna having directivity is directed to the floor surface. According to the present invention, when the receiving antenna is an antenna having directivity, and the transmitting antenna is an omnidirectional antenna, the receiving antenna is directed to the direction of the floor on the ceiling in the same room, The transmitting antenna is installed in a direction in which the receiving antenna has no directivity, and the indoor environment state signal is converted into a radio signal and emitted from the transmitting antenna. The radio signal radiated from the transmitting antenna is reflected by a material that reflects radio waves on the floor, and is received by the receiving antenna.

[0015] A third invention (an invention according to claim 3) is an environment condition detector installed in a return air introduction path in a ceiling interior space and detecting an indoor environment condition, and an environment condition signal from the environment condition detector. To a radio signal, a transmitting antenna for transmitting a radio signal from the transmitting unit, a receiving antenna for receiving a radio signal from the transmitting antenna, and an environmental status signal for receiving the radio signal received by the receiving antenna. And a receiving unit that demodulates the signal, at least one of the transmitting antenna and the receiving antenna is an antenna having directivity, and the transmitting antenna and the receiving antenna are directed to the ceiling in the same room of a building in which a material that reflects radio waves is disposed. The gender direction is oriented toward the floor. According to the present invention, when the receiving antenna is an antenna having directivity, and the transmitting antenna is an omnidirectional antenna, the receiving antenna is directed to the direction of the floor on the ceiling in the same room, The transmitting antenna is installed in a direction without directivity of the receiving antenna. In addition, an environmental condition detector is installed in the return air introduction path in the interior space of the ceiling, and the indoor environmental condition signal detected by the environmental condition detector is converted into a radio signal by the transmitter, and the radio signal from the transmitter is converted to a radio signal. Radiated from the transmitting antenna. The radio signal radiated from the transmitting antenna is reflected by a material that reflects radio waves on the floor, and is received by the receiving antenna.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments. FIG. 1 is a configuration diagram of an air conditioning control system to which the present invention is applied. In the figure, 1-1 is the interior space (living room), 1-2 is the ceiling interior space, 1-3
Is a ceiling material. In the ceiling interior space 1-2, a VAV unit (variable air volume adjustment unit) 2, a receiver (controller) 3, and a transmitter 4 are installed. In this embodiment, a space combining the living room 1-1 and the ceiling interior space 1-2 is defined as a room. Further, the ceiling material 1-3, the front and back surfaces of the ceiling material 1-3, and the ceiling interior space 1-2 are collectively defined as a ceiling.

The VAV unit 2 receives an opening command value from the receiver 3 and adjusts the amount of air supplied to the living room 1-1 through the air supply hole 5. The transmitter 4 includes a transmission antenna 4-1 and a temperature sensor 4-2 therein, and is mounted using a T-bar 7 provided on an edge portion of a return air hole (return air slit) 6. In FIG. 1, for convenience, the transmitting antenna 4
-1 is drawn outside the transmitter 4. In this embodiment, the transmitting antenna 4-1 is omnidirectional.

The receiver 3 is fixed to a ceiling suspension bolt 8 and has a telescopic rod antenna (1/4 wavelength ground plane antenna) 3-1. In this embodiment, a rod antenna (receiving antenna) 3-1
Has directivity, and the direction of the directivity is directed toward the floor surface.

In FIG. 1, reference numeral 8 denotes a window, 9 denotes a beam located in the ceiling interior space 1-2, 10 denotes a metal H steel in the beam 9, and 11 denotes a floor. Reinforcing bars 12 are embedded in the floor 11 in a lattice shape in the concrete. Also,
Below the concrete of the floor 11, a deck plate 13 used for concrete construction is installed. An iron plate is generally used for the deck plate 13.

FIG. 2 is a side sectional view showing the mounting state of the transmitter 4. The transmitter 4 is fixed to a mounting bracket 14 mounted on the T-bar 7. The mounting bracket 14 has legs 14A, 14B, and 14C at its bottom (see FIG. 3), and is mounted such that the base 7-1 of the T-bar 7 is sandwiched between the legs 14A, 14B, and 14C. In this case, the leg 14A is the ceiling interior space 1- of the base 7-1 of the T-bar 7.
The two sides are pressed against each other with elastic force, and the legs 14B, 14C
Presses against the surface of the base 7-1 on the living room 1-1 side. Leg 1
Terminal portions 4B1 and 14C1 of 4B and 14C are bent in an L-shape, and these terminal portions 4B1 and 14C1 engage with end surface 7-1a of base 7-1. As a result, the mounting bracket 14 is movably fixed to an arbitrary position on the T bar 7, and the mounting position of the transmitter 4 can be adjusted while sliding to the desired position.

The mounting bracket 14 has a mounting surface 14-1.
Are formed with engaging claws 14-D (see FIG. 4). Also, the transmitter 4 protrudes from the back of the housing 4-3,
Bridges 4-3a and 4-3b are formed (see FIG. 3). Bridge 4-3a, slit 4-3a ₁ on its downward 4-3b, 4-3b ₁ are formed. Also,
The transmitter 4 is formed with guide rails 4-3c and 4-3d projecting from the rear surface of the housing 4-3.

As shown in FIG. 4, the transmitter 4 is mounted from the side of the mounting bracket 14. That is, the transmitter 4 is slid along the mounting surface 14-1 of the mounting bracket 14 from the lateral direction of the mounting bracket 14. Then, the engaging claw 14-D which is formed on the mounting surface 14-1 enters the slit 4-3a ₁ bridge 4-3a, the guide rail 4
-3c, while being guided by the 4-3d enters slit 4-3b ₁ bridge 4-3b. As a result, the transmitter 4
As shown in FIG. 3, it is fixed to the mounting bracket 14.

The housing 4-3 of the transmitter 4 is provided with an air intake hole 4-3e on the living room 1-1 side and an air exhaust hole 4-3f on the ceiling interior space 1-2 side. Thereby, the return air from the living room 1-1 to the return air passage 1-2b via the return air hole 6 passes through the inside of the housing 4-3. A transmission antenna 4-1, a temperature sensor 4-2, a circuit board 4-4, and a battery 4-5 (see FIG. 5) are provided inside the housing 4-3. The temperature sensor 4-2 is placed in a return air passage inside the housing 4-3 and detects a return air temperature.

FIG. 5 is a block diagram showing a hardware configuration of the transmitter 4. The circuit board 4-4 includes a CPU 4-4a, a transmission circuit 4-4b, a power supply circuit 4-4c, an identification code setting switch 4-4d, a reset circuit 4-4e, and a sensor unit A / D.
Circuit power supply 4-4f, differential amplifier 4-4g, A / D circuit power control switch 4-4h, transmission circuit power control switch 4
-4i, crystal oscillators 4-4j, 4-4k, etc. The circuit board 4-4 converts the return air temperature (return air temperature signal) detected by the temperature sensor 4-2 into digital data,
An identification code and an error correction code are added to generate a radio signal, which is sent to the transmission antenna 4-1.

FIG. 6 is a perspective view showing how the receiver 3 is mounted. The receiver 3 is mounted on the ceiling suspension bolt 8 with an electric path support bracket (for example, 6-9B manufactured by Negros Electric Works) 15-1, 15-.
2 for mounting. That is, the electrical path support brackets 15-1 and 15-2 are attached at predetermined intervals in the vertical direction of the ceiling suspension bolt 8. Also, the receiver 3 is mounted on the bracket 1
6 is attached with screws 17-1 and 17-2. The bracket 16 to which the receiver 3 is attached is screwed to a screw 17-3,
Attach it to the circuit support brackets 15-1 and 15-2 by 17-4. The receiving antenna 3-1 is a telescopic rod antenna (1/4 wavelength ground plane antenna),
It can be folded and stored on the housing side of the receiver 3, and projects horizontally when used.

FIG. 7 is a block diagram showing a hardware configuration of the receiver 3. The receiver 3 includes a receiving antenna 3-1 and C
PU 3-2, receiving circuit 3-3, clock reconstruction waveform shaping circuit 3-4, crystal oscillator 3-5, power supply circuit 3-6, protection circuit 3-7, identification code setting switch 3-8, LED display section 3-9 and the like. The LED display unit 3-9 is used for receiving confirmation and the like.

[Transmission of Return Air Temperature from Transmitter 4 to Receiver 3] In the transmitter 4, the temperature sensor 4-2 is connected to the living room 1--1.
1 is detected and sent to the circuit board (transmitter) 4-4 as a return air temperature signal. The circuit board 4-4 converts the return air temperature signal from the temperature sensor 4-2 into digital data, adds an identification code and an error correction code to a radio signal,
Send to transmitting antenna 4-1. The transmission antenna 4-1 radiates a radio signal from the circuit board 4-4. In this case, since the transmitting antenna 4-1 is non-directional, a radio wave of uniform intensity is radiated in all directions.

The radio signal radiated from the transmitting antenna 4-1 tries to reach the receiving antenna 3-1 as a direct wave through the beam 9. However, since the beam 9 includes the H steel 10 made of metal, it hinders direct wave transmission.

On the other hand, the radio signal from the transmitting antenna 4-1 is also radiated toward the floor 11. Reinforcing bars 12 are embedded in the floor 11 in a grid pattern in the concrete.
In this case, since the interval between the reinforcing bars 12 is short, it is equivalent to a reflection surface for radio waves. A deck plate 13 is provided under the concrete of the floor 11, and the deck plate 1 is provided.
Since an iron plate is generally used for 3, the deck plate 13 also reflects radio waves. However, even when the deck plate 13 is a wooden board and no reflection occurs, reflection occurs only by the reinforcing bar 12.

That is, in this embodiment, the radio wave radiated from the transmitting antenna 4-1 is a direct wave,
The radio wave attenuated by the steel 10 and traveling toward the floor 11 is reflected by the reinforcing bar 12 and the deck plate 13 in the floor. The radio wave reflected by the reinforcing rod 12 and the deck plate 13 reaches the receiving antenna 3-1. The receiving antenna 3-1 has directivity, and the direction of the directivity is directed toward the floor surface.

As a result, the gain of receiving the reflected wave arriving from the floor surface direction is higher than that of the attenuated direct wave arriving from the lateral direction, so that the influence of interference can be reduced and the generation of a dead zone is prevented. In addition, the transmitter 4 and the receiver 3 can be arranged in the ceiling interior space 1-2 irrespective of the existence of the beam 9 in which the H steel 10 is embedded. Stable signal transmission can be realized. In this case, since the transmitter 4 is installed in the ceiling interior space 1-2, the appearance of the living room 1-1 is not spoiled.

Here, as the radio wave radiated from the transmission antenna 4-1, a radio wave in a frequency band that is easily reflected by a metal material such as a floor, a ceiling, or a partition wall of a building is selected. That is, in the present embodiment, it is assumed that the light is reflected by the reinforcing rods 12 and the deck plate 13 in the floor surface. Therefore, a wavelength λ = 10 W, which is about 10 times the mesh interval W, is used as the frequency (transmission frequency) f of the radio wave radiated from the transmission antenna 4-1. That is, when the speed of light is c [m / s] as the transmission frequency f, f ≦ c /
(10 W) is used. If the transmission frequency f is low, the size of the antenna becomes large. Therefore, if a high transmission frequency f is used as long as the above expression is satisfied, it is effective in downsizing.

FIG. 8 is an error distribution (experimental result) when both the receiving antenna 3-1 and the transmitting antenna 4-1 in FIG. 1 are omnidirectional antennas. Radius 4-5
There are some errors on the circle of m. Where 1
The 00% error indicates that communication was performed a plurality of times during a certain unit time, and no accurate communication was possible.

FIG. 9 shows the conditions shown in FIG. 1, that is, the receiving antenna 3-1 is a directional antenna, the transmitting antenna 4-1 is a non-directional antenna, and the receiving antenna 3
9 is an error distribution (experimental result) when the directivity direction of −1 is directed to the floor surface direction. By doing so, 4
100% error that existed on a circle of ~ 5m disappears,
It can be confirmed that stable communication has been performed. In addition, the communicable area is wide even in a long distance part, and the transmitter 4
Also, it can be easily confirmed that the area where the receiver 3 can be installed is widened.

In this embodiment, the receiving antenna 3-1 has directivity, and the transmitting antenna 4-1
Is omnidirectional (see FIG. 10A), but the receiving antenna 3-1 may be omnidirectional and the transmitting antenna 4-1 may have directivity (see FIG. 10B). Both the receiving antenna 3-1 and the transmitting antenna 4-1 may have directivity (see FIG. 10C). In this case, the directional antenna directs the direction of the directivity toward the floor surface.

The receiving antenna 3-1 as shown in FIG.
Ideally, both the transmitting antenna 4-1 and the transmitting antenna 4-1 have directivity. However, when the distance between the ceiling and the floor is relatively short as in an office environment, the receiving antenna 3-1 has directivity as shown in FIG. 10A, and the transmitting antenna 4-1 has a non-directional antenna. However, FIG.
As shown in (b), the transmitting antenna 4-1 has directivity,
The receiving antenna 3-1 may be an omnidirectional antenna. In particular, when it is necessary to reduce the size of the transmitter 4 and it is difficult to make the transmitting antenna 4-1 have directivity, FIG.
0 (a).

In this embodiment, as the antenna having directivity, a dipole antenna, a loop antenna, a ground plane antenna, a whip antenna, a rod antenna, a corner antenna, or the like can be used. Since a one-wavelength loop antenna or the like also has directivity in the upper floor direction symmetrically with the floor surface, it is effective to use an antenna having a reflector.

Further, in this embodiment, the transmitter 4 is installed in the ceiling interior space 1-2, but may be installed on the wall surface of the living room 1-1 as shown in FIG. In this case, the temperature detector 4-2 incorporated in the transmitter 4 detects the room temperature. In FIG. 11, reference numeral 18 denotes an air conditioning duct (made of metal).

In this embodiment, the return air temperature is detected as the indoor environment state. However, environmental states such as "humidity", "occupied", "fire" and "disaster prevention" are detected. You may do so. That is, the indoor environment state signal indicating the environmental state such as “humidity”, “occupied room”, “fire”, “disaster prevention” and the like may be converted into a radio signal and transmitted from the transmission antenna 4-1.

In this embodiment, transmission from transmitter 4 to receiver 3 has been described.
-1, using the receiving antenna 3-1 for both transmitting and receiving,
It is also possible to perform two-way communication. In this embodiment, the number of the transmitters 4 is one, but a configuration in which a plurality of the transmitters 4 are provided may be adopted.

[0041]

As is apparent from the above description, according to the present invention, in the first invention, when the receiving antenna is a directional antenna and the transmitting antenna is a non-directional antenna, the transmitting antenna is Installed in a direction where the receiving antenna does not have directivity, the indoor environment state signal is converted to a radio signal and radiated from the transmitting antenna, and the radio signal radiated from the transmitting antenna is reflected by a material that reflects radio waves in the building Then, the signal is received by the receiving antenna, the influence of the interference between the direct wave and the reflected wave can be reduced, the generation of a dead zone can be prevented, and the installation area of the transmitter and the receiver can be expanded. In addition, even if there are obstacles such as air-conditioning ducts, beams, and columns between the transmitter and receiver, stable signal transmission is possible, and the transmitter can be installed in the ceiling interior space in various buildings. It becomes possible not to spoil the aesthetics of the room. .

In the second invention, when the receiving antenna is an antenna having directivity and the transmitting antenna is an omnidirectional antenna, the receiving antenna directs the direction of the directivity toward the floor in the ceiling of the same room. The transmitting antenna is installed in a direction in which the receiving antenna has no directivity, and the indoor environment state signal is converted into a radio signal and radiated from the transmitting antenna.
The radio signal radiated from the transmitting antenna is reflected by the material that reflects the radio wave on the floor and is received by the receiving antenna, and the influence of the interference between the direct wave from the lateral direction and the reflected wave from the floor is reduced. Thus, the dead zone can be prevented, and the installation area of the transmitter and the receiver can be increased. Also, even if there are obstacles such as air-conditioning ducts, beams, and columns between the transmitter and receiver, stable signal transmission can be achieved, and the transmitter can be installed in the ceiling interior space in various buildings. Thus, it is possible to prevent the indoor aesthetics from being spoiled.

In the third invention, when the receiving antenna is an antenna having directivity and the transmitting antenna is an omnidirectional antenna, the direction of the directivity of the receiving antenna is directed to the floor in the ceiling of the same room. Therefore, the transmitting antenna is installed in a direction in which the receiving antenna has no directivity, and an environmental condition detector is installed in the return air introduction path in the space inside the ceiling, and an indoor environmental condition signal detected by the environmental condition detector is transmitted. The signal is converted into a radio signal by the transmission unit, the radio signal from the transmission unit is radiated from the transmission antenna, and the radio signal radiated from the transmission antenna is reflected by a material that reflects radio waves on the floor and received by the reception antenna. Can reduce the influence of interference between the direct wave from the lateral direction and the reflected wave from the floor, prevent the occurrence of dead zones, and expand the area where transmitters and receivers can be installed. So as to. In addition, stable signal transmission can be performed even when obstacles such as air-conditioning ducts, beams, and columns exist between the transmitter and the receiver, and the ceiling of the environmental condition detector, the transmission unit, and the transmission antenna can be used in various buildings. The transmitter can be installed in the internal space, that is, the transmitter can be installed in the internal space of the ceiling in various buildings, and the aesthetic appearance of the room can be maintained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an air conditioning control system to which the present invention is applied.

FIG. 2 is a side sectional view showing a mounting state of a transmitter in the air conditioning control system.

FIG. 3 is a partially broken perspective view showing a mounting state of a transmitter viewed from a direction A in FIG. 2;

FIG. 4 is a perspective view for explaining a method of attaching a transmitter to a fitting.

FIG. 5 is a block diagram illustrating a hardware configuration of a transmitter.

FIG. 6 is a perspective view showing how the receiver is mounted.

FIG. 7 is a block diagram illustrating a hardware configuration of a receiver.

FIG. 8 is a diagram showing an error distribution (experimental results) when both the receiving antenna and the transmitting antenna in FIG. 1 are omnidirectional antennas.

FIG. 9 shows the conditions shown in FIG. 1 (the receiving antenna has directivity,
Error distribution (experimental results) with transmitting antenna omnidirectional
FIG.

FIG. 10 is a diagram illustrating a combination of directivity and omnidirectionality of a receiving antenna and a transmitting antenna.

FIG. 11 is a configuration diagram showing another example of an air conditioning control system to which the present invention is applied.

FIG. 12 is a block diagram illustrating a “temperature detecting device” disclosed in Japanese Utility Model Laid-Open No. 3-124141.

FIG. 13 is a configuration diagram of an air conditioning control system to which the temperature detecting device is applied.

FIG. 14 is an explanatory diagram regarding directivity of a loop antenna.

FIG. 15 is a diagram for explaining a dead zone that occurs when a method of receiving a direct wave from a transmitter is used.

[Explanation of symbols]

1-1 indoor interior space (living room) 1-2 ceiling internal space 1-3 ceiling material, 2 VAV unit, 3 receiver, 3-1 receiving antenna, 4 transmitter, 4- DESCRIPTION OF SYMBOLS 1 ... Transmission antenna, 4-2 ... Temperature sensor, 9 ... Beam, 10 ... H steel,
11 ... floor, 12 ... steel bar, 13 ... deck plate, 18
... air conditioning duct.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuichi Tanaka 2-3-3 Kandajicho, Chiyoda-ku, Tokyo Obayashi Gumi Tokyo Head Office (72) Inventor Koji Kobayashi 2-12-19 Shibuya, Shibuya-ku, Tokyo No. Yamatake Ha Newel Co., Ltd. (72) Inventor Akira Matsuda 2-12-19 Shibuya, Shibuya-ku, Tokyo Yamatake Ha Newell Co., Ltd. (72) Makoto Morikawa 2--12-19 Shibuya, Shibuya-ku, Tokyo Yamatake Inside of Honeywell Co., Ltd. (72) Inventor Mitsutomi Ugajin 2-12-19, Shibuya, Shibuya-ku, Tokyo Inside Yamatake Honeywell Co., Ltd.

Claims (3)

[Claims] 1. A transmitting antenna and a receiving antenna are arranged in the same room of a building in which a material that reflects radio waves is arranged, at least one of the transmitting antenna and the receiving antenna is an antenna having directivity, and the transmitting antenna is The receiving antenna is installed in a direction without directivity of the transmitting antenna in a direction without directivity of the receiving antenna, and an indoor environment state signal is converted into a radio signal and transmitted from the transmitting antenna. A method of transmitting and receiving indoor environment conditions, wherein a radio signal transmitted from an antenna and reflected by a material that reflects radio waves in the building is received by the receiving antenna. 2. The indoor environment state according to claim 1, wherein the transmitting antenna and the receiving antenna are installed on a ceiling in the same room, and the direction of the directivity of the antenna is directed to the floor surface. Transmission / reception method. 3. An environmental condition detector installed in the return air introduction path in the ceiling interior space for detecting an indoor environmental condition, a transmitting unit for converting an environmental condition signal from the environmental condition detector into a radio signal, A transmitting antenna for transmitting a radio signal from the transmitting unit, a receiving antenna for receiving a radio signal from the transmitting antenna, and a receiving unit for demodulating the radio signal received by the receiving antenna into an environmental state signal; At least one of the antenna and the receiving antenna is an antenna having directivity, and the transmitting antenna and the receiving antenna are arranged on a ceiling in the same room of a building in which a material that reflects radio waves is arranged. An indoor environment state transmission / reception device characterized by being arranged in a direction.