Sensor system, communication device, and program

Abstract

To enable a communication device to accurately identify a sensor arranged near the communication device.SOLUTION: A sensor system 10 includes a plurality of sensors 20 for detecting physical amount and transmitting the detected physical amount with a radio signal, and a communication device 30 for receiving radio signals sent from each of the plurality of sensors 20. The communication device 30 includes an index value acquisition part 35M for acquiring an index value, representing degree of attenuation for signal strength at reception to signal strength at transmission of the radio signal, for each of the plurality of sensors 20, and an identification part 35N for identifying a sensor 20 with preferable reception state of the radio signal within the plurality of sensors 20 based on index values acquired for each of the plurality of sensors 20.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a sensor system, a communication device, and a program used in an air conditioning system or the like. [Background technology]

[0002] VAV air conditioning systems have been known as conventional air conditioning systems. As disclosed in Patent Document 1, this air conditioning system includes a plurality of sensors that measure the temperatures of a plurality of air conditioning zones that divide a space to be air-conditioned, and a plurality of damper devices that are provided in one-to-one correspondence with the plurality of sensors and the plurality of air conditioning zones. Each damper device receives the temperature measured by the corresponding sensor and controls the amount of conditioned air supplied (air volume) from the air conditioner to the corresponding air conditioning zone based on the received temperature. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-70945 Summary of the Invention [Problem to be solved by the invention]

[0004] In the air conditioning system described in Patent Document 1, each sensor is stationary. However, it is also conceivable to configure each sensor as a portable device that wirelessly transmits detected air temperature to a communication device for the damper device, making its location easily adjustable. This allows the sensor location to be easily adjusted to match the layout, for example, when changing the office layout. However, in such a case, it is assumed that a sensor corresponding to a certain damper device is located in a second air conditioning zone other than the first air conditioning zone corresponding to the damper device, and another sensor is located in the first air conditioning zone. Under such an assumption, it is desirable for the communication device of the damper device to accurately identify, from among multiple sensors with which it can communicate, a sensor located in the corresponding air conditioning zone, in other words, a sensor located near the communication device. Such a problem of accurately identifying a sensor located near a communication device may also arise in systems other than air conditioning systems.

[0005] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to enable a communication device to accurately identify a sensor arranged in the vicinity of the communication device. [Means for solving the problem]

[0006] In order to solve the above problem, the sensor system of the present invention comprises a plurality of sensors that detect physical quantities and transmit the detected physical quantities as wireless signals, and a communication device that receives the wireless signals transmitted by each of the plurality of sensors, wherein the communication device comprises an index value acquisition unit that acquires, for each of the plurality of sensors, an index value that indicates the degree of attenuation of the signal strength at the time of reception relative to the signal strength at the time of transmission of the wireless signal, and an identification unit that identifies, from the plurality of sensors, a sensor with the best reception conditions for the wireless signal based on the index value acquired for each of the plurality of sensors.

[0007] As an example, the index value acquisition unit acquires multiple index values ​​for each of the multiple sensors by acquiring the index value multiple times at a predetermined period, and the identification unit derives statistical values ​​of the multiple index values ​​for each of one or more sensors among the multiple sensors, including index values ​​acquired within a first predetermined period going back from the present, and identifies the sensor from the one or more sensors with the optimal reception conditions based on the derived statistical values.

[0008] As one example, the identifying unit derives the statistical value after excluding from the plurality of index values ​​any index values ​​acquired by the index value acquiring unit earlier than a second predetermined period going back from the present.

[0009] As an example, the identification unit derives a statistical value of the plurality of index values ​​for each of the one or more sensors for which the number of the plurality of index values ​​is equal to or greater than a predetermined number.

[0010] As an example, the specifying unit derives, as the statistical value, a statistical value of one or more index values ​​within a certain range from an index value having the smallest degree of attenuation among the plurality of index values.

[0011] As an example, the specifying unit transmits the physical quantity received from the specified sensor with the optimal reception condition to a processing execution unit that executes processing based on the physical quantity.

[0012] As an example, an air conditioning system is provided with an individual air conditioning zone unit that supplies conditioned air to one air conditioning zone obtained by dividing an air conditioning space, and the plurality of sensors are arranged in the air conditioning space and detect the ambient air temperature as the physical quantity, and the individual air conditioning zone unit is provided with the communication device and the processing execution unit, and the processing execution unit executes a process to control the amount of conditioned air supplied from the individual air conditioning zone unit based on the air temperature received from the sensor with the optimal reception conditions.

[0013] As an example, the individual air-conditioning zone unit includes a hollow member that forms a flow path for the conditioned air, and the communication device includes an antenna that receives the wireless signal, and the antenna is provided on an exposed surface of the inner surface of the hollow member that is exposed through an opening facing the air-conditioning space of the hollow member.

[0014] A communication device according to the present invention is a communication device that receives physical quantities detected by a plurality of sensors via wireless signals, and includes an index value acquisition unit that acquires, for each of the plurality of sensors, an index value that indicates the degree of attenuation of signal strength at the time of reception relative to the signal strength at the time of transmission of the wireless signal; and an identification unit that identifies, from the plurality of sensors, a sensor that has the best reception conditions for the wireless signal based on the index value acquired for each of the plurality of sensors. Equipped with.

[0015] The program of the present invention is stored in a memory unit within a communication device that receives physical quantities detected by each of a plurality of sensors via wireless signals, and causes the communication device to perform the following processes: acquiring, for each of the plurality of sensors, an index value that represents the degree of attenuation of the signal strength at the time of reception relative to the signal strength at the time of transmission of the wireless signal; and identifying, from among the plurality of sensors, a sensor with the best reception conditions for the wireless signal based on the index value acquired for each of the plurality of sensors. [Effects of the Invention]

[0016] According to the present invention, a communication device can accurately identify a sensor placed in the vicinity of the communication device. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a configuration diagram of an air conditioning system including a sensor system according to an embodiment of the present invention. [Figure 2] The upper drawing in FIG. 2 is an elevation view of the individual air conditioning zone unit, and the lower drawing is a bottom view of the individual air conditioning zone unit. [Figure 3]FIG. 3 is a hardware configuration diagram of the communication device. [Figure 4] FIG. 4 is a block diagram for explaining the operation of the communication device. [Figure 5] FIG. 5 is a flowchart of the communication process. [Figure 6] FIG. 6 is a diagram showing the configuration of the temperature table. [Figure 7] FIG. 7 is a diagram showing the configuration of the attenuation value table. [Figure 8] FIG. 8 is a flowchart of the identification process. DETAILED DESCRIPTION OF THE INVENTION

[0018] A sensor system according to an embodiment of the present invention will be described below with reference to the drawings.

[0019] The sensor system 10 according to this embodiment shown in FIG. 1 includes sensors 20-1 to 20-n (n is an integer of 2 or greater) and individual air conditioning zone units 30-1 to 30-m, each of which includes m (m is an integer of 2 or greater) communication devices 33 (see also FIG. 2). In FIG. 1, the individual air conditioning zone units 30-1 to 30-m are arranged in a row in the left-right direction of FIG. 1, but in reality, they are arranged in a matrix pattern in the front-rear and left-right directions when viewed from above. The sensors 20-1 to 20-n are collectively referred to as sensors 20. The individual air conditioning zone units 30-1 to 30-m are collectively referred to as individual air conditioning zone units 30.

[0020] This sensor system 10 constitutes part of a VAV (Variable Air Volume) type central air conditioning system 1 (hereinafter simply referred to as air conditioning system 1). Specifically, sensor 20 is arranged in air-conditioned space R, which is the target of air conditioning, and is configured as a temperature sensor that detects the ambient temperature. Individual air-conditioning zone unit 30 is configured as a damper device that takes in conditioned air, which is air cooled or heated by air conditioners 3 of air-conditioning system 1, via duct 7, adjusts the taken-in conditioned air to the required supply volume, and supplies it to the air-conditioned space R. Sensor 20 transmits the detected ambient temperature via a wireless signal. Individual air-conditioning zone unit 30 receives the temperature detected by sensor 20 via a wireless signal via communication device 33, and controls the supply volume of conditioned air based on the received temperature.

[0021] The sensor 20 is a small, portable temperature sensor. The user U can move the sensor 20 to a desired location. For example, when the seating layout of the air-conditioned space R in an office room is changed, the position of the sensor 20 is also changed accordingly. The air-conditioned space R may have a non-reserved address system, in which case the user U may move the sensor 20 when moving seats. The sensor 20 modulates various information, including the detected temperature, into a wireless signal (e.g., radio wave) and outputs the modulated signal. In addition to the temperature, the various information includes a sensor ID that identifies the sensor 20 itself and the signal strength (e.g., radio wave strength) E1 of the wireless signal at the time of transmission. The various information is also referred to as temperature information. The signal strength E1 at the time of transmission is represented by the signal strength at a position a certain distance (e.g., 1 meter) from the sensor 20. The signal strength E1 is assumed to be a preset value in the sensor 20.

[0022] The sensor 20 detects the temperature and transmits a wireless signal at a predetermined cycle T1 (for example, every two seconds). The sensor 20 transmits, for example, radio waves conforming to the BLE (Bluetooth (registered trademark) Low Energy) standard as the wireless signal. The sensor 20 may include an illuminance sensor or the like, and may increase or decrease the predetermined cycle T1 depending on whether the surroundings are dark or bright. For example, the sensor 20 may set the predetermined cycle T1 to one minute when the surroundings are dark, and to two seconds when the surroundings are bright.

[0023] Individual air conditioning zone units 30-1 to 30-m, which function as damper devices for adjusting the amount of conditioned air supplied, are arranged in one-to-one correspondence with the multiple air conditioning zones Z1 to Zm obtained by dividing the air-conditioned space R. The air conditioning zones Z1 to Zm are also collectively referred to as air conditioning zones Z. Each individual air conditioning zone unit 30 is installed on the ceiling of the corresponding air conditioning zone Z and supplies conditioned air to the corresponding air conditioning zone Z. Based on the temperature measured by a sensor 20 arranged within the corresponding air conditioning zone Z (or in the vicinity thereof; the same applies hereinafter), each individual air conditioning zone unit 30 controls the amount of conditioned air supplied to the air conditioning zone Z so that the temperature approaches a set temperature. The set temperature is supplied from an air conditioner controller 5 that controls the air conditioners 3 of the air conditioning system 1.

[0024] As described above, the sensor 20 is movable and can be placed near the user U. When the sensor 20 is placed in the corresponding air conditioning zone Z, the individual air conditioning zone unit 30 can adjust the amount of conditioned air supplied to the air conditioning zone Z so that the temperature detected by the sensor 20 approaches the set temperature. This allows the temperature around the user U to be controlled to a comfortable temperature.

[0025] 2, the individual air conditioning zone unit 30 includes a unit main body 31, an opening / closing unit 32, a communication device 33, and an individual air conditioning zone controller 38. The air conditioning zone Z (air conditioning zone Z to be air-conditioned) corresponding to one individual air conditioning zone unit 30 is also referred to as the corresponding air conditioning zone Z.

[0026] The unit body 31 forms a flow path L1 for supplying conditioned air (cool air or warm air) to the corresponding air-conditioning zone Z. The unit body 31 is a hollow member made of, for example, metal, and includes a first cylindrical portion 31A, a second cylindrical portion 31B, and a box-shaped portion 31C. The first cylindrical portion 31A is connected to a duct 7 (FIG. 1) through which conditioned air from the air conditioner 3 flows. The second cylindrical portion 31B is connected to a blow-out portion F (FIG. 1) that blows conditioned air to the corresponding air-conditioning zone Z. The first cylindrical portion 31A and the second cylindrical portion 31B are connected to the box-shaped portion 31C.

[0027] The opening / closing unit 32 is provided inside the first cylindrical portion 31A. The opening / closing unit 32 is configured to include blades that open and close the flow path L1, and a drive mechanism that includes an actuator and the like and drives the blades (detailed structure is not shown).

[0028] The communication device 33 is configured to be able to communicate with multiple sensors 20. The communication device 33 receives wireless signals transmitted by the multiple sensors 20 (sensors 20 within a communication distance). The communication device 33 demodulates the received wireless signals to collect temperature information represented by the wireless signals, and identifies the sensor 20 with the best reception conditions for the wireless signal (e.g., the smallest attenuation value D) based on the attenuation value D of the signal strength of the wireless signal (details will be described later). A sensor 20 with good reception conditions for the wireless signal (a small attenuation value D) means that the sensor 20 is close to the communication device 33. In other words, identifying the sensor 20 with the best reception conditions can also be considered as identifying the sensor 20 located near the communication device 33 (or the individual air-conditioning zone unit 30), for example, the sensor 20 located within the air-conditioning zone Z. The communication device 33 supplies the temperature included in the wireless signal from the identified sensor 20 to the individual air-conditioning zone controller 38.

[0029] The communication device 33 includes a circuit board on which various circuits, such as the antenna 34A and the detection circuit 34B shown in FIG. 3, are mounted. The communication device 33 is located on the inner surface of the unit body 31, at the center of the underside of the top plate of the box-shaped portion 31C. This center of the underside is exposed downward through the opening of the second cylindrical portion 31B facing the air-conditioned space R of the unit body 31. As a result, the communication device 33, particularly the antenna 34A, is exposed downward and visible through the interior of the second cylindrical portion 31B when the individual air-conditioning zone unit 30 is viewed from below, as shown in the bottom view in the lower part of FIG. 2. The antenna 34A of the communication device 33 positioned in this manner easily receives wireless signals from the sensor 20 located below it, i.e., in the corresponding air-conditioning zone Z. This effect is particularly pronounced when the unit body 31 is made of metal.

[0030] The individual air conditioning zone controller 38 uses the air temperature supplied from the communication device 33 as a feedback value and the set temperature from the air conditioner controller 5 as a target value, and controls the opening degree of the opening / closing part 32 of the individual air conditioning zone unit 30, i.e., the flow path L1, to control the supply amount of conditioned air supplied from the individual air conditioning zone unit 30. In this way, the air temperature of the corresponding air conditioning zone Z is controlled.

[0031] As shown in FIG. 3, the communication device 33 includes a signal receiving unit 34 and a microcomputer 35.

[0032] The signal receiving unit 34 includes an antenna 34A that receives wireless signals from all sensors 20 located within wireless communication distance, a detection circuit 34B that detects the signal strength E2 of the wireless signals received by the antenna 34A, and a demodulation circuit 34C that demodulates the wireless signals received by the antenna to obtain temperature information. The signal receiving unit 34 further includes an A / D (Analog / Digital) converter 34D that converts the demodulated or detected temperature information and signal strength into digital data and supplies it to the microcomputer 35.

[0033] The microcomputer 35 includes a processor 35A such as a CPU (Central Processing Unit) and a RAM (Random Access Memory) 35B that functions as the main memory of the processor 35A. The microcomputer 35 also includes a ROM (Read Only Memory) 35C that stores programs and data executed or used by the processor 35A. The processor 35A executes a program (computer program) stored in the ROM 35C to operate as a temperature acquisition unit 35L, an index value acquisition unit 35M, and an identification unit 35N shown in FIG. 4. The RAM 35B is provided with a temperature table 35T1 and a damping value table 35T2, which will be described later.

[0034] The communication device 33 receives wireless signals transmitted at a predetermined period T1 from all sensors 20 located within a wireless communication distance, using an antenna 34A of a signal receiving unit 34. Each time a wireless signal is received, the signal receiving unit 34, the temperature acquiring unit 35L, and the index value acquiring unit 35M cooperate to execute the receiving process shown in FIG.

[0035] First, the signal receiving unit 34 (detection circuit 34B) detects the signal strength E2 of the received wireless signal (step S11). The signal receiving unit 34 (demodulation circuit 34C) demodulates the received wireless signal and acquires the temperature information represented by the wireless signal (step S12). The signal receiving unit 34 (A / D converter 34D) converts the detected or acquired signal strength E2 and temperature information into digital data (step S13). The sensor ID and temperature of the temperature information converted into digital data are supplied to the temperature acquiring unit 35L (FIGS. 3 and 4). The sensor ID and signal strength E1 of the temperature information converted into digital data are supplied to the index value acquiring unit 35M together with the signal strength E2 (FIG. 3).

[0036] The temperature acquisition unit 35L records the sensor ID and temperature supplied from the signal receiving unit 34 in a temperature table 35T1 in the RAM 35B (step S14). As shown in FIG. 6, the temperature table 35T1 records a plurality of pairs of sensor IDs associated with temperatures detected by the sensors 20 identified by the sensor IDs. The specific content of the sensor IDs is assumed to be the same as the reference numerals of the sensors 20. Specifically, the sensor ID of sensor 20-1 is assumed to be 20-1, and the sensor ID of sensor 20-2 is assumed to be 20-2.

[0037] In step S14, if the sensor ID supplied from the signal receiving unit 34 is not recorded in the temperature table 35T1, the temperature acquiring unit 35L newly registers the sensor ID and the temperature. If the sensor ID from the signal receiving unit 34 is recorded in the temperature table 35T1, the temperature acquiring unit 35L updates the temperature associated with the sensor ID in the temperature table 35T1 to the temperature from the signal receiving unit 34. As a result, the latest temperature detected by the sensor 20 is stored in the temperature table 35T1.

[0038] The index value acquiring unit 35M acquires the attenuation value D by calculating the attenuation value D [dB] of the received wireless signal based on the signal strengths E1 and E2 supplied from the signal receiving unit 34 (step S15). The index value acquiring unit 35M further acquires the current time as the acquisition time T of the attenuation value D (step S16). The current time is acquired using a real-time clock or the like. The current time may include the date. The current time can also be considered the time the wireless signal was received or the time the temperature was detected.

[0039] The index value acquiring unit 35M records the acquired attenuation value D and acquisition time T in the attenuation value table 35T2 in association with the sensor ID from the signal receiving unit 34 (step S17). As shown in Fig. 7, the attenuation value table 35T2 records the sensor ID and a pair of the attenuation value D and acquisition time T for the sensor 20 identified by the sensor ID in association with each other. The attenuation value table 35T2 stores up to 30 pairs of pairs per sensor ID.

[0040] In step S17, if the sensor ID from the signal receiving unit 34 has not already been recorded in the attenuation value table 35T2, the index value acquiring unit 35M associates the sensor ID with a pair of the attenuation value D and the acquisition time T and records them in the attenuation value table 35T2. If the sensor ID has already been recorded in the attenuation value table 35T2, the index value acquiring unit 35M records the pair of the attenuation value D and the acquisition time T in the attenuation value table 35T2 in association with the sensor ID. At this time, if the attenuation value table 35T2 already has 30 pairs of the attenuation value D and the acquisition time T stored therein, the index value acquiring unit 35M updates the pair with the oldest acquisition time T among them to the pair of the attenuation value D and the acquisition time T acquired this time. As a result, the attenuation value table 35T2 records the latest 30 attenuation values ​​for each sensor ID.

[0041] The identification unit 35N in Fig. 4 executes the identification process illustrated in Fig. 8 at a predetermined period T2 longer than the predetermined period T1 (for example, a 10-second period longer than a 2-second period). In the identification process, the identification unit 35N refers to the attenuation value table to identify the sensor 20 for which the wireless signal is optimally received by the communication device 33, in other words, the sensor 20 that is transmitting a wireless signal that is optimally received by the communication device 33, and supplies the latest air temperature detected by the identified sensor 20 to the individual air conditioning zone controller 38. In this identification process, the attenuation values ​​D used to derive statistical values ​​(described below) used to identify the sensor 20 are narrowed down from all the attenuation values ​​D in the attenuation value table 35T2 (steps S31 to S35), thereby improving the accuracy of identifying the sensor 20. The sensor 20 having the optimal wireless signal reception conditions at the communication device 33 can be said to be the representative (representative for air conditioning) of multiple sensors 20 that may be located within the air conditioning zone Z from the perspective of the communication device 30, and therefore, hereinafter, this sensor 20 will also be referred to as the representative sensor 20.

[0042] In the identification process of FIG. 8, the identification unit 35N first deletes from the attenuation value table 35T2 any set that includes an acquisition time T (e.g., an acquisition time T earlier than 60 minutes ago) that is earlier than a predetermined period P1 (e.g., 60 minutes) prior to the current time (step S31). As a result, attenuation values ​​at older times are deleted from the attenuation value table 35T2. If such a set does not exist, step S31 is skipped. The same applies to other steps, and if there is no target data in another step, the step is skipped.

[0043] After step S31, the identification unit 35N deletes a sensor ID for which the number of pairs of the corresponding attenuation value D and acquisition time T has become zero in the attenuation value table 35T2 (step S32). Furthermore, the identification unit 35N deletes records of sensor IDs for which the latest acquisition time T is earlier than a predetermined period P2 (e.g., 10 minutes) prior to the current time (step S33). Step S33 leaves records of sensor IDs including attenuation values ​​D acquired within the predetermined period P2 prior to the current time. In step S33, for example, when the current time is February 2, 2022, 13:20:00, the attenuation value table 35T2 has the contents of FIG. 7, and the pair of attenuation values ​​D of A30 [dB] and B30 [dB] (the rightmost pair in FIG. 7) is the pair for the latest acquisition time T, the sensor ID "20-5" and all pairs of the associated attenuation value D and acquisition time T (i.e., one row of records) are deleted. The sensors 20 with the sensor IDs that are the subject of the deletion process have been unable to communicate with the communication device 33 for a long time. This prevents a sensor 20 that has moved outside the corresponding air conditioning zone Z from being mistakenly identified as the representative sensor 20. The predetermined period P2 is, for example, shorter than the predetermined period P1. In step S31, which is premised on the execution of step S32, old attenuation values ​​of sensors 20 that are still able to communicate with the communication device 33 are deleted.

[0044] Thereafter, the identification unit 35N identifies a sensor ID for which a predetermined number (e.g., 10) or more pairs of the attenuation value D and the acquisition time T are recorded (step S34). As a result, the sensors 20 that have been located within a communication distance with the communication device 33 for a certain period of time are identified, and sensors 20 that were only temporarily present in an area where communication with the communication device 33 is possible are excluded from the candidates for the representative sensor 20. Thereafter, the identification unit 35N identifies the minimum attenuation value D (the attenuation value D with the least attenuation) among the corresponding attenuation values ​​D for each identified sensor ID, and identifies attenuation values ​​D of 1 or more (attenuation values ​​D with the least attenuation) that are within a certain range (e.g., a range of +13 dB) from the identified minimum attenuation value D (step S35). The identified attenuation values ​​D of 1 or more are used to derive statistics, which will be described later, for identifying the representative sensor 20. Therefore, by identifying the attenuation value D in step S35, abnormal values, such as those that occur when the signal strength of the wireless signal received from the sensor 20 suddenly weakens, are excluded from the attenuation value D used to derive the statistical value, thereby preventing an incorrect sensor 20 from being identified as the representative sensor 20 due to such influences.

[0045] The identification unit 35N then performs statistical processing on the attenuation values ​​D, which are one or more, identified in step S35 for each sensor ID to derive a statistical value (step S36). The statistical value may be derived using a function or by referencing a table. The statistical value is a value indicating the tendency of the degree of attenuation of the wireless signal indicated by the attenuation values ​​D, which are one or more. Here, the statistical value is an average value, but it may also be a median, etc. The identification unit 35N identifies the sensor ID corresponding to the smallest statistical value (the statistical value with the least attenuation of the wireless signal) among the statistical values ​​derived for each sensor ID as the sensor ID of the representative sensor 20 (step S37). Since the smallest statistical value indicates the least attenuation of the wireless signal, the identification of the sensor ID identifies the sensor 20 with the optimal wireless signal reception conditions at the communication device 33. On the other hand, the processes of steps S31 to S35 above have eliminated sensors 20 with less optimal reception conditions, such as sensors that have temporarily passed by or have already moved from a nearby position.

[0046] The identification unit 35N then refers to the temperature table 35T1 based on the sensor ID in step S37, acquires the temperature corresponding to the sensor ID, and transmits it to the individual air conditioning zone controller 38 (step S38). The acquired and transmitted temperature is the most recent temperature detected by the representative sensor 20.

[0047] The individual air conditioning zone controller 38 controls the opening / closing unit 32 using the temperature from the communication device 33, i.e., the latest temperature detected by the representative sensor 20, as a feedback value and the set temperature from the air conditioner controller 5 as a target value.

[0048] As described above, the sensor system 10 includes a communication device 33 and multiple sensors 20 (particularly, multiple sensors 20 within a communicable distance from the communication device 33). The index value acquisition unit 35M of the communication device 33 acquires, for each of the multiple sensors 20, an index value (attenuation value D) representing the degree of attenuation of the signal strength E2 at the time of reception relative to the signal strength E1 at the time of transmission of the wireless signal. Furthermore, the identification unit 35N identifies, from among the multiple sensors 20, a representative sensor 20 that provides the optimal wireless signal reception conditions at the communication device 33, based on the index values ​​acquired for each of the multiple sensors 20. In particular, a sensor 20 with an index value having a small degree of attenuation is identified from one or more sensors 20 excluding sensors 20 that have moved. The index value may be the attenuation value D or, for example, the signal strength E2 itself, as long as it is guaranteed that the signal strength E1 at the time of transmission of each wireless signal transmitted from each of the multiple sensors 20 is the same. The index value may be any value that represents the attenuation of the signal strength.

[0049] The signal strength of a wireless signal decreases with increasing distance from the source of transmission. In the above configuration, the representative sensor 20 is identified based on an index value that indicates the degree of wireless signal attenuation, thereby enabling accurate identification of the representative sensor 20. Note that the representative sensor 20 can be identified by using the index value, not the statistical value. The identified sensor 20 can be the sensor 20 located near the communication device 33 (the sensor closest to the communication device 33 if there are no obstacles), for example, the sensor 20 located within the air conditioning zone Z. Therefore, by accurately identifying the representative sensor 20, the sensor 20 located near the communication device 33 (the sensor 20 optimal for use in air conditioning control) can be accurately identified. Furthermore, in the above embodiment, the communication device 33 can identify the representative sensor 20 without recognizing its own location, thereby enabling identification of the representative sensor 20 through simple processing.

[0050] Furthermore, the index value acquisition unit 35M acquires multiple index values ​​for each of the multiple sensors 20 by acquiring the index value multiple times at a predetermined period T1 (see the attenuation value table). The acquired multiple index values ​​may be stored in various storage units, including not only RAM but also non-volatile storage devices. The identification unit 35N derives statistics of the multiple index values ​​for one or more sensors 20 among the multiple sensors 20, including index values ​​acquired within a predetermined period P2 prior to the present, from the multiple index values ​​acquired by the index value acquisition unit 35M (steps S33 and S36, etc.). Then, the identification unit 35N identifies a representative sensor 20 from the one or more sensors 20 based on the derived statistics for each of the one or more sensors 20 (step S37). The sensor 20 corresponding to the statistical value indicating the least attenuation of the wireless signal becomes the representative sensor 20 of the communication device 33. This configuration makes it possible to identify a representative sensor 20 from among the sensors 20 that recently received a wireless signal. The sensor 20 that recently received a wireless signal is likely still located within a distance capable of wireless communication with the communication device 33. Therefore, the representative sensor 20 is identified with high accuracy, and thereby the sensors 20 arranged near the communication device 33 are identified with high accuracy. Note that "each of one or more sensors 20" includes the meaning of one sensor 20 and the meaning of each of multiple sensors 20.

[0051] Furthermore, the identification unit 35N excludes from the plurality of index values ​​index values ​​acquired by the index value acquisition unit 35M more than a predetermined period P1 going back from the present, and then derives the statistical value (step S31, etc.). This prevents old index values ​​from being used to derive the statistical value. Therefore, when the sensor 20 moves, index values ​​before the movement are prevented from being used to derive the statistical value, and the representative sensor 20 is identified with high accuracy, thereby allowing the sensor 20 arranged near the communication device 33 to be identified with high accuracy.

[0052] Furthermore, the identification unit 35N derives statistics of the multiple index values ​​for each of the one or more sensors among the multiple sensors 20, for which the multiple index values ​​acquired by the index value acquisition unit 35M include index values ​​acquired within a predetermined period P2 going back from the present, and the number of the multiple index values ​​is equal to or greater than a predetermined number (steps S33 and S34, etc.). As a result, a representative sensor 20 is identified from among the sensors 20 that have been placed within a distance capable of wireless communication with the communication device 33 for a certain period of time, and therefore, for example, a sensor 20 that was only temporarily present in an area capable of wireless communication with the communication device 33 is prevented from being identified as the representative sensor 20. Therefore, the representative sensor 20 is identified with high accuracy, and thereby the sensors 20 placed near the communication device 33 are identified with high accuracy.

[0053] Furthermore, the identification unit 35N derives, as the statistical value, one or more index values ​​within a certain range from the index value with the smallest degree of attenuation among the multiple index values ​​(step S35, etc.). The signal strength E2 of the wireless signal on which the index value is based is unstable due to the presence or absence of an obstacle or the like between the communication device 33 and the sensor 20, and the signal strength E2 may suddenly decrease. When the signal strength E2 suddenly decreases, the attenuation of the wireless signal becomes large, and a sensor 20 that should have been identified as the representative sensor 20 may be identified as not being the representative sensor 20. In the above embodiment, the effect of a sudden decrease in signal strength E2 on the statistical value can be reduced, and the representative sensor 20 can be identified with high accuracy, thereby accurately identifying the sensor 20 arranged near the communication device 33.

[0054] Furthermore, the individual air-conditioning zone unit 30 further includes a processing execution unit, such as an individual air-conditioning zone controller 38, that executes processing based on the temperature from the representative sensor 20. The multiple sensors 20 are arranged in the air-conditioning space R to detect the ambient temperature, and the individual air-conditioning zone unit 30 is a damper device that supplies conditioned air to one air-conditioning zone Z obtained by dividing the air-conditioning space R. The processing execution unit executes, as the processing, processing to control the amount of conditioned air supplied based on the temperature from the representative sensor 20. In this way, appropriate air conditioning is achieved even if the sensor 20 is moved. The processing execution unit may also perform processing to transmit the temperature from the sensor 20 to a higher-level device. In this way, the processing executed by the processing execution unit may be processing to output the temperature from the sensor 20.

[0055] Furthermore, the individual air conditioning zone unit 30 includes a unit body 31 made of a hollow member that forms a flow path for the conditioned air, and an antenna 34A that receives wireless signals from the sensor 20. The antenna 34A is provided on an exposed surface (the center of the underside of the top surface) of the inner surface of the unit body 31 that is exposed through an opening facing the air-conditioned space R of the unit body 31. This makes it easier for the individual air conditioning zone unit 30 to receive, via the antenna 34A, wireless signals from the sensor 20 in the air-conditioning zone Z to which the conditioned air is supplied.

[0056] The above-described embodiment can be modified in various ways. Modifications are listed below, and at least some of the modifications can be combined as appropriate.

[0057] Some of the steps in FIGS. 5 and 8 may be omitted as appropriate.

[0058] The communication device 33 may have any hardware configuration. At least a portion of the units 35L to 35N of the communication device 33 may be configured with one or more logic circuits. Examples of logic circuits include an ASIC (Application Specific Integrated Circuit) and an FPGA (Field Programmable Gate Array). The program may be stored in a non-transitory storage medium. At least a portion of the units 35L to 35N may be provided in the individual air conditioning zone controller 38 of the individual air conditioning zone unit 30. In other words, the communication device 30 may be configured by combining the communication device 30 and the individual air conditioning zone controller 38.

[0059] The sensor 20 may detect a physical quantity and transmit the detected physical quantity via a wireless signal. Examples of the physical quantity include the temperature, humidity, and brightness around the sensor 20. The individual air-conditioning zone unit 30 may be a device that operates in accordance with the physical quantity detected by the sensor 20. If the physical quantity is humidity, the individual air-conditioning zone unit 30 may be replaced by a humidifier or air conditioner that humidifies the air based on the humidity from the representative sensor 20. If the physical quantity is brightness, the individual air-conditioning zone unit 30 may be replaced by a lighting device that controls lighting based on the brightness from the nearest sensor 20. The communication device 33 may be a device that outputs the physical quantity from the sensor 20 to another device, such as a higher-level device. For example, the communication device 33 may identify the sensor with the best wireless signal reception condition from multiple sensors as a representative sensor representing the multiple sensors. The sensor 20 may transmit a wireless signal indicating the detected physical quantity in response to an inquiry from the communication device 33. The communication between the communication device 33 and the sensor 20 includes not only two-way communication but also a mode in which the communication device 33 receives a wireless signal unilaterally transmitted from the sensor 20 as in the above embodiment.

[0060] Although the present invention has been described above with reference to the embodiments and modifications, the present invention is not limited to the above embodiments and modifications. For example, the present invention includes various modifications to the above embodiments and modifications that can be understood by a person skilled in the art within the scope of the technical concept of the present invention. The configurations listed in the above embodiments and modifications can be combined as appropriate within a range that does not contradict each other. [Explanation of symbols]

[0061] 1...central air conditioning system, 3...air conditioner, 5...air conditioner controller, 7...duct, 10...sensor system, 20-1 to 20-n...sensors, 30-1 to 30-m...individual air conditioning zone unit, 31...unit main body, 31A...first cylindrical portion, 31B...second cylindrical portion, 31C...box-shaped portion, 32...opening / closing portion, 33...communication device, 34...signal receiving portion, 34A...antenna, 34B...detection circuit, 34C...demodulation circuit, 34D...A / D converter, 35...microcomputer, 35A...processor, 35L...temperature acquisition portion, 35M...index value acquisition portion, 35N...identification portion, 38...individual air conditioning zone controller, F...blowing portion, L1...flow path, R...air-conditioned space, U...user, Z1 to Zm...air-conditioning zone.

Claims

1. a plurality of sensors that detect physical quantities and transmit the detected physical quantities as wireless signals; a communication device that receives the wireless signals transmitted by each of the plurality of sensors; The communication device an index value acquiring unit that acquires, for each of the plurality of sensors, an index value that indicates a degree of attenuation of the signal strength at the time of reception of the wireless signal relative to the signal strength at the time of transmission; and a specifying unit that specifies a sensor having an optimal reception condition for the wireless signal from among the plurality of sensors based on the index value acquired for each of the plurality of sensors. Sensor system.

2. the index value acquisition unit acquires a plurality of index values ​​by acquiring the index value for each of the plurality of sensors a plurality of times at a predetermined period; The identification unit deriving a statistical value of the plurality of index values ​​for each of one or more sensors among the plurality of sensors, the plurality of index values ​​including index values ​​acquired within a first predetermined period going back from the present; identifying a sensor having the best reception condition from the one or more sensors based on the derived statistical value; The sensor system of claim 1 .

3. the identifying unit derives the statistical value after excluding, from the plurality of index values, index values ​​acquired by the index value acquiring unit earlier than a second predetermined period going back from the present; The sensor system of claim 2 .

4. the identification unit derives a statistical value of the plurality of index values ​​for each of the one or more sensors for which the number of the plurality of index values ​​is equal to or greater than a predetermined number; The sensor system according to claim 2 or 3.

5. the specifying unit derives, as the statistical value, a statistical value of one or more index values ​​within a certain range from an index value having a smallest degree of attenuation among the plurality of index values; The sensor system according to any one of claims 2 to 4.

6. the specifying unit transmits the physical quantity received from the specified sensor having the optimal reception condition to a processing execution unit that executes processing based on the physical quantity. The sensor system according to any one of claims 1 to 5.

7. An individual air conditioning zone unit is provided which divides the air-conditioned space and supplies conditioned air to one of the air-conditioning zones, the plurality of sensors are arranged in the air-conditioned space and detect an ambient air temperature as the physical quantity; the individual air conditioning zone unit includes the communication device and the processing execution unit, the processing execution unit executes, as the processing, a process of controlling the supply amount of conditioned air supplied from the individual air conditioning zone unit based on the temperature received from the sensor with the optimal reception condition. The sensor system of claim 6 .

8. The individual air conditioning zone unit includes a hollow member that forms a flow path for the conditioned air, the communication device includes an antenna for receiving the radio signal; The antenna is provided on an exposed surface of the inner surface of the hollow member that is exposed through an opening of the hollow member facing the air-conditioning space. The sensor system of claim 7 .

9. A communication device that receives physical quantities detected by a plurality of sensors via wireless signals, an index value acquiring unit that acquires, for each of the plurality of sensors, an index value that indicates a degree of attenuation of the signal strength at the time of reception of the wireless signal relative to the signal strength at the time of transmission; an identification unit that identifies a sensor having an optimal reception condition for the wireless signal from among the plurality of sensors based on the index value acquired for each of the plurality of sensors; A communication device comprising:

10. The physical quantities detected by each of the plurality of sensors are stored in a storage unit in a communication device that receives the physical quantities by wireless signal, a process of acquiring, for each of the plurality of sensors, an index value representing a degree of attenuation of the signal strength at the time of reception of the wireless signal relative to the signal strength at the time of transmission; a process of identifying a sensor having the best wireless signal reception condition from among the plurality of sensors based on the index value acquired for each of the plurality of sensors; A program that causes the communication device to execute the above.

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