CN112105964B - Sensor system, air conditioning system, object detection method, and recording medium - Google Patents

Abstract

The invention provides an object detection system, a sensor system, an air conditioning system, an object detection method and a program capable of enlarging a region of a detectable object. The object detection system (1) is provided with a switching unit (12), a determination unit (11), and a background correction unit (13). A switching unit (12) switches the detection area between a plurality of areas including at least the specific area. A judging unit (11) judges whether or not an object is present in the detection area based on the result of comparing the output data of the temperature sensor (2) for detecting the temperature of the detection area with the background data corresponding to each of the plurality of areas. A background correction unit (13) corrects background data corresponding to a specific region based on the amount of temperature change during the period when the detection region is a region other than the specific region.

Description

Sensor system, air conditioning system, object detection method and recording medium

Technical Field

The present disclosure generally relates to an object detection system, a sensor system, an air conditioning system, an object detection method and a program, and more specifically, to an object detection system, a sensor system, an air conditioning system, an object detection method and a program for detecting an object based on the output of a temperature sensor.

Background technique

Patent Document 1 describes an air conditioner having a human sensor for detecting the presence and position of a person in a room. The air conditioner controls a fan unit and the like with reference to the presence and position of a person in a room determined by a detection result (detection signal) of the human sensor.

For example, the air conditioner can determine the direction of the left and right wind deflectors based on the detection results of the human body sensor, so that the airflow is directed to the indoor occupants with high accuracy. In addition, according to the action of the human body sensor, the airflow can also track the movement of the indoor occupants, so that even if the indoor occupants move, the airflow can accurately reach the indoor occupants. As a result, the indoor occupants can reliably get a cool feeling based on the cooling effect of the airflow.

As such a human body sensor, an object detection system that detects a target object (person in the room) in the detection area based on the output of a temperature sensor that detects the temperature of the detection area can be used.

Prior Art Literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2014-126295

Summary of the invention

However, in the above-mentioned object detection system, the area where the object can be detected is limited to the field of view of the temperature sensor, and it may not be possible to detect, for example, an object (indoor person) that is indoors but outside the field of view of the temperature sensor.

The present disclosure is completed in view of the above reasons, and its purpose is to provide an object detection system, a sensor system, an air conditioning system, an object detection method and a program that can expand the area where detectable objects can be detected.

An object detection system according to one embodiment of the present disclosure includes a switching unit, a judgment unit, and a background correction unit. The switching unit switches the detection area between a plurality of areas including at least a specific area. The judgment unit judges the presence or absence of an object in the detection area based on a comparison result of output data of a temperature sensor that detects the temperature of the detection area and background data corresponding to each of the plurality of areas. The background correction unit corrects the background data corresponding to the specific area based on the temperature change during the period when the detection area is an area other than the specific area.

A sensor system according to one aspect of the present disclosure includes the object detection system and the temperature sensor.

An air conditioning system according to one aspect of the present disclosure includes the sensor system and an air conditioner that operates based on an output of the determination unit.

An object detection method according to one embodiment of the present disclosure includes switching processing, judgment processing and background correction processing. The switching processing is a processing for switching the detection area between multiple areas including at least a specific area. The judgment processing is a processing for judging the presence or absence of an object in the detection area based on a comparison result of the output data of a temperature sensor for detecting the temperature of the detection area and the background data corresponding to each of the multiple areas. The background correction processing is a processing for correcting the background data corresponding to the specific area based on the temperature change during the period when the detection area is an area other than the specific area.

A program according to one aspect of the present disclosure is a program for causing a computer system to execute the object detection method.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the configuration of an object detection system, a sensor system, and an air conditioning system according to Embodiment 1. FIG.

2A and 2B are explanatory diagrams of the operation of the object detection system when there is an object.

3A and 3B are diagrams for explaining the operation of the object detection system when there is no object.

4A and 4B are diagrams for explaining the determination process in the object detection system.

FIG. 5 is a flowchart showing an example of the operation of the object detection system.

FIG. 6 is a flowchart showing an example of the operation of the object detection system.

FIG. 7 is a flowchart showing an example of operations related to the determination process of the object detection system.

FIG. 8 is a diagram for explaining the operation of the object detection system.

FIG. 9 is a flowchart showing an operation example of the object detection system according to the comparative example.

10A and 10B are explanatory diagrams of the operation of the object detection system.

11A to 11C are diagrams for explaining the operation of the object detection system according to the modification of the first embodiment.

FIG. 12 is an explanatory diagram of the operation of the object detection system according to the first structural example of the second embodiment.

Fig. 13A is an explanatory diagram of the operation of the object detection system according to the second configuration example of the second embodiment. Fig. 13B is an explanatory diagram of the operation of the object detection system according to the third configuration example of the second embodiment.

Detailed ways

(Implementation Method 1)

(1) Overview

As shown in FIG1 , the object detection system 1 according to the present embodiment constitutes a sensor system 20 together with the temperature sensor 2. In other words, the sensor system 20 according to the present embodiment includes the object detection system 1 and the temperature sensor 2. In addition, the sensor system 20 constitutes an air conditioning system 30 together with the air conditioner 3. In other words, the air conditioning system 30 according to the present embodiment includes the sensor system 20 and the air conditioner 3.

The object detection system 1 is a system for detecting an object 5 (see FIG. 2A ) in a detection area 4 (see FIG. 2A ) based on the output of the temperature sensor 2. In the object detection system 1, the presence or absence of the object 5 in the detection area 4 is determined based on the comparison result of the output data D1 (see FIG. 4B ) of the temperature sensor 2 and the background data D2 (see FIG. 4B ). That is, in the object detection system 1, the object 5 is captured as a heat source, and the presence of the object 5 is detected based on the temperature change in the detection area 4 caused by the presence of the object 5 in the detection area 4.

In the air conditioning system 30, for example, the air conditioner 3 operates based on the detection result of the sensor system 20. As an example, the sensor system 20 used in the air conditioning system 30 uses a "person" existing in the room where the air conditioner 3 is installed as the object 5, and determines whether there is a person (object 5) in the room. In addition, when the sensor system 20 determines that there is no person (object 5) in the room, the air conditioner 3 performs control such as switching the operation mode to the power saving mode or stopping the operation.

As shown in FIG1 , the object detection system 1 involved in the present embodiment includes a switching unit 12, a judgment unit 11, and a background correction unit 13. The switching unit 12 switches the detection area 4 between a plurality of areas A1 to A3 (refer to FIG2A ) including at least a specific area. The judgment unit 11 judges the presence or absence of the object 5 in the detection area 4 based on the comparison result of the output data D1 of the temperature sensor 2 and the background data D2. The temperature sensor 2 detects the temperature of the detection area 4. The background data D2 corresponds to the plurality of areas A1 to A3, respectively. The background correction unit 13 corrects the background data D2 corresponding to the specific area based on the temperature change amount during the period when the detection area 4 is an area other than the specific area.

According to this structure, the detection area 4 in which the temperature is detected by the temperature sensor 2 is switched between the plurality of areas A1 to A3 by the switching unit 12, so that the area in which the object 5 can be detected can be expanded compared to the case where the detection area 4 is fixed. That is, in the object detection system 1 having the above structure, the area in which the object 5 can be detected is not limited to the field of view of the temperature sensor 2, and the object 5 outside the field of view of the temperature sensor 2 can also be detected.

Furthermore, in the object detection system 1 according to the present embodiment, the background correction unit 13 corrects the background data D2 corresponding to the specific area based on the temperature change amount during the period when the detection area 4 is an area other than the specific area. Thus, even if the detection area 4 is switched between the plurality of areas A1 to A3, the reliability (detection accuracy) of the detection of the object 5 in the object detection system 1 is not easily reduced. This point is described in detail in the column "(2.3) Action".

(2) Details

Hereinafter, the object detection system 1 , the sensor system 20 , and the air conditioning system 30 according to the present embodiment will be described in more detail.

(2.1) Overall structure

As described above, the air conditioning system 30 according to the present embodiment includes the sensor system 20 and the air conditioner 3. In the present embodiment, as an example, the air conditioning system 30 includes only one air conditioner 3, but the present invention is not limited to this example, and the air conditioning system 30 may include a plurality of air conditioners 3.

In addition, as described above, the sensor system 20 involved in this embodiment includes the object detection system 1 and the temperature sensor 2. In this embodiment, the sensor system 20 also includes a drive unit 21. Moreover, in this embodiment, all the structural elements of the sensor system 20 are integrated with the air conditioner 3. In other words, all the structural elements of the air conditioning system 30 are provided in the housing 31 of one air conditioner 3 (refer to FIG. 2A).

In this embodiment, as an example, a case where the air conditioning system 30 is introduced into a residential facility such as a single-family house or a multi-family house is described. Specifically, the housing 31 of the air conditioner 3 is installed on the wall or ceiling of a room 40 (refer to FIG. 2A ) in the residential facility. In this case, the air conditioner 3 adjusts the temperature, humidity, air cleanliness, air flow, etc. in the room 40.

The sensor system 20 used in the air conditioning system 30 regards a "person" existing in the room 40 where the air conditioner 3 is installed as the object 5, and determines whether the person (object 5) exists in the room 40. That is, the area to be detected by the sensor system 20 and the area to be air conditioned by the air conditioner 3 are set in the same space (inside the room 40). Therefore, when the sensor system 20 determines that there is no person (object 5) in the room 40, the air conditioner 3 performs control such as switching the operation mode to the power saving mode or stopping the operation.

Furthermore, the sensor system 20 according to the present embodiment can recognize not only the presence or absence of a person (object 5), but also the position of a person in the room 40 and the number of people (number of people) in the room 40. Therefore, the air conditioner 3 performs control such as changing the direction (wind direction) or air volume of the airflow according to at least one of the position and number of people in the room 40.

In addition, in the present embodiment, the temperature sensor 2 is an infrared array sensor in which a plurality of sensor elements for detecting infrared rays are respectively arranged in two dimensions. The "infrared rays" referred to in the present disclosure are at least light rays (heat rays) radiated from the human body, for example, light having a wavelength of about 10 [μm]. Such a temperature sensor 2 outputs a thermal image representing the temperature distribution of a detection area set within a given field of view angle. The "thermal image" referred to in the present disclosure is an image composed of a plurality of pixels arranged in two dimensions and using the detected temperatures of each of the plurality of sensor elements as pixel values. Here, as an example, the temperature sensor 2 is an infrared array sensor in which 64 sensor elements are arranged in two dimensions, 8 in the X-axis direction and 8 in the Y-axis direction. Therefore, the temperature sensor 2 outputs a thermal image in which the number of pixels in the X-axis direction and the Y-axis direction is 8 pixels as output data D1. In other words, the output data D1 is image data containing a plurality of pixels each having a temperature value as a pixel value.

In addition, the driving unit 21 generates power for moving the temperature sensor 2. In the present embodiment, the driving unit 21 drives the temperature sensor 2 so that the temperature sensor 2 rotates around the rotation axis. The rotation axis of the temperature sensor 2 is, for example, an axis along the vertical direction or inclined at a given angle relative to the vertical direction. Here, the driving unit 21 changes the orientation of the temperature sensor 2 by rotating the temperature sensor 2, thereby achieving switching of the detection area 4 between multiple areas A1 to A3 (refer to FIG. 2A). That is, the temperature sensor 2 is configured to be rotatable in the horizontal direction (translation direction) by the driving unit 21, and the detection area 4 is switched according to the orientation of the temperature sensor 2 in the horizontal direction.

The details are described in the column "(2.2) Structure of the object detection system", but in this embodiment, it is assumed that the detection area 4 is switched among the three areas of the first area A1, the second area A2, and the third area A3. Therefore, as shown in FIG2A, the drive unit 21 moves the temperature sensor 2 back and forth within a given rotation angle range, causing the temperature sensor 2 to perform a shaking motion (swinging motion), thereby switching the detection area 4 between the first area A1, the second area A2, and the third area A3. Specifically, the drive unit 21 includes a motor, and causes the temperature sensor 2 to perform a shaking motion according to a drive signal from the switching unit 12 described later.

(2.2) Structure of the object detection system

Next, the structure of the object detection system 1 will be described.

As shown in FIG. 1 , the object detection system 1 according to the present embodiment includes a background updating unit 14 , an acquiring unit 15 , and a background storage unit 16 in addition to a determining unit 11 , a switching unit 12 , and a background correcting unit 13 .

Here, the determination unit 11, the switching unit 12, the background correction unit 13, and the background update unit 14 are realized by, for example, a processing unit 10 mainly composed of a computer system such as a microcomputer. The processing unit 10 mainly consists of a computer system including a processor and a memory, and the processor executes a program recorded in the memory, thereby realizing the functions of the determination unit 11, the switching unit 12, the background correction unit 13, and the background update unit 14. The program may be recorded in the memory in advance, provided through an electric communication line such as the Internet, or provided by being recorded in a non-volatile recording medium such as a memory card.

The processing unit 10 is connected to an acquisition unit 15 and a background storage unit 16. Furthermore, the processing unit 10 is connected to a drive unit 21 and an air conditioner 3. Here, the processing unit 10 and the drive unit 21 or the air conditioner 3 can be connected as long as they can transmit information. They are not limited to a structure in which they are directly connected to each other, and they can also be connected using a communication interface, for example.

As described above, the determination unit 11 determines the presence or absence of the object 5 in the detection area 4 based on the comparison result of the output data D1 of the temperature sensor 2 and the background data D2. The "background data" referred to in the present disclosure is data that serves as a reference for the output data D1 when the determination unit 11 determines the presence or absence of the object 5, and is data indicating the temperature (thermal image in this embodiment) of the detection area 4 when the object 5 does not exist. In this embodiment, basically, the output data D1 of the temperature sensor 2 when the object 5 does not exist is used as the background data D2.

Here, in this embodiment, as described above, the output data D1 is image data including a plurality of pixels each having a temperature value as a pixel value. Therefore, the background data D2, which is a reference of the output data D1, is also image data including a plurality of pixels each having a temperature value as a pixel value, similarly to the output data D1. Specifically, the background data D2 is a thermal image in which the number of pixels in the X-axis direction and the Y-axis direction is 8 pixels.

In addition, the "based on the comparison result" mentioned in the present disclosure includes not only the case based on the result (difference) of directly comparing the output data D1 and the background data D2, but also the case substantially based on the result of comparing the output data D1 and the background data D2. That is, the judgment of the presence or absence of the object 5 in the judgment unit 11 is implemented by any of the following methods 1 to 3 as an example. The first method is a method of judging the presence or absence of the object 5 based on the result (difference) of directly comparing the output data D1 and the background data D2, and the second method and the third method are methods of judging the presence or absence of the object 5 without directly comparing the output data D1 and the background data D2.

That is, in the first method, the judgment unit 11 calculates differential data by obtaining the difference between the output data D1 and the background data D2, and compares the calculated differential data with the threshold value, thereby judging the presence or absence of the object 5 in the detection area 4. In this case, the judgment unit 11 judges that the object 5 is "present" based on the fact that the differential data exceeds the threshold value. In this embodiment, it is assumed that the judgment unit 11 adopts the first method. The processing involved in the judgment of the presence or absence of the object 5 in the judgment unit 11 is described in detail in the "(2.3) Action" column.

In the second method, the judgment unit 11 does not obtain differential data, but compares the output data D1 with the synthetic data obtained by adding a threshold value to the background data D2, thereby judging the presence or absence of the object 5 in the detection area 4. In this case, the judgment unit 11 judges that the object 5 is "present" based on the output data D1 exceeding the synthetic data. In the third method, the judgment unit 11 does not obtain differential data, but compares the synthetic data obtained by subtracting the threshold value from the output data D1 with the background data D2, thereby judging the presence or absence of the object 5 in the detection area 4. In this case, the judgment unit 11 judges that the object 5 is "present" based on the synthetic data exceeding the background data D2.

In addition, in the present embodiment, the detection area 4 is switched between the multiple areas A1 to A3 by the switching unit 12, so the background data D2 is set corresponding to the multiple areas A1 to A3. That is, the background data D2 is set for each area (the first area A1, the second area A2 or the third area A3) that is a candidate for the detection area 4. Then, the judgment unit 11 judges the presence or absence of the object 5 in the detection area 4 based on the comparison result of the background data D2 corresponding to the area as the detection area 4 among the multiple areas A1 to A3 and the output data D1 of the temperature sensor 2. That is, in the case where the detection area 4 is the area A1 among the multiple areas A1 to A3, the judgment unit 11 judges the presence or absence of the object 5 in the detection area 4 based on the comparison result of the background data D2 corresponding to the area A1 and the output data D1 of the temperature sensor 2.

In the object detection system 1 according to the present embodiment, the object 5 is a moving object. More strictly, the object 5 is a "person" existing in the room 40. Therefore, the judgment unit 11 judges that the object 5 is "absent" when the object 5 (person) does not exist in the detection area 4. If the object 5 (person) as a moving object intrudes into the detection area 4 from this state, the judgment unit 11 judges that the object 5 is "present". The object 5 can be any moving object, not limited to a person, and may be, for example, a small animal.

Here, the judgment unit 11 judges the presence or absence of the object 5 multiple times while the detection area 4 is in the same area. That is, in the present embodiment, the detection area 4 is switched between the multiple areas A1 to A3 by the switching unit 12. While the detection area 4 stops at any one of the multiple areas A1 to A3, the judgment unit 11 performs the judgment on the presence or absence of the object 5 multiple times. In other words, during the period from the switching of the detection area 4 to the next switching of the detection area 4, the judgment unit 11 performs the judgment on the presence or absence of the object 5 multiple times.

As described above, the switching unit 12 switches the detection area 4 between the multiple areas A1 to A3 including at least a specific area. That is, the detection area 4 that becomes the detection object of the temperature sensor 2 is not fixed, but is switched by the switching unit 12. The multiple areas that become candidates for the detection area 4 include more than 3 areas. In the present embodiment, it is a premise to switch the detection area 4 among the three areas of the first area A1, the second area A2, and the third area A3. That is, the multiple areas that become candidates for the detection area 4 include the three areas of the first area A1, the second area A2, and the third area A3.

Specifically, as shown in FIG2A , among the three regions obtained by dividing the space in the room 40 into three parts in a plan view, the central region becomes the first region A1, the region on the right becomes the second region A2, and the region on the left becomes the third region A3 when viewed from the temperature sensor 2. Here, as an example, the viewing angle of the temperature sensor 2 in a plan view is approximately 60 degrees, and a range of approximately 180 degrees centered on the front of the air conditioner 3 is divided into three equal parts, thereby forming three regions, namely the first region A1, the second region A2, and the third region A3.

In the present embodiment, as described above, the driving unit 21 causes the temperature sensor 2 to perform a shaking motion, thereby switching the detection area 4 between the plurality of areas A1 to A3. Therefore, the switching unit 12 outputs a driving signal to the driving unit 21, and controls the driving unit 21 by the driving signal, thereby switching the detection area 4 between the plurality of (here, 3) areas A1 to A3.

In addition, the "specific area" mentioned in the present disclosure is included in multiple areas A1~A3, and is an arbitrary area of concern. In the present embodiment, it is assumed that the first area A1, the second area A2, and the third area A3 may all become "specific areas". That is, the specific area is not fixed, and the specific area changes depending on which of the first area A1, the second area A2, and the third area A3 is focused on. For example, when the first area A1 is a "specific area", the second area A2 and the third area A3 become "areas outside the specific area". Similarly, when the second area A2 is a "specific area", the first area A1 and the third area A3 become "areas outside the specific area", and when the third area A3 is a "specific area", the first area A1 and the second area A2 become "areas outside the specific area".

In addition, in the present embodiment, the switching unit 12 performs switching of the detection area 4 at intervals of a given time (for example, tens of seconds to several minutes). That is, the switching of the detection area 4 performed by the switching unit 12 is not performed continuously, but is performed intermittently. Specifically, for example, if the driving unit 21 is operated and the switching unit 12 switches the detection area 4 from the first area A1 to the second area A2, the driving unit 21 is temporarily stopped, and the detection area 4 is temporarily fixed to the second area A2. If the second area A2 becomes the detection area 4 and a given time has passed, the driving unit 21 is operated and the switching unit 12 switches the detection area 4 from the second area A2 to the first area A1. Among them, the switching unit 12 temporarily fixes the detection area 4 to the first area A1 by temporarily stopping the driving unit 21. Therefore, the driving unit 21 does not work all the time, but only works intermittently when the detection area 4 is switched. Therefore, compared with a structure in which the driving unit 21 operates continuously, the power consumption in the driving unit 21 can be suppressed to a small amount, and the degradation of the driving unit 21 can also be reduced. Furthermore, when the temperature sensor 2 and the object detection system 1 are connected by a cable, the load applied to the cable can also be suppressed to a small amount.

The background correction unit 13 corrects the background data D2 corresponding to the specific area based on the temperature change amount during the period when the detection area 4 is an area other than the specific area. Here, the period when the detection area 4 is an area other than the specific area is set as the "first period", and the period when the detection area 4 is the specific area is set as the "second period". That is, in the first period, the detection area 4 is set in the area other than the specific area, and in the second period, the detection area 4 is set in the specific area. That is, when the background correction unit 13 sequentially switches between the first period when the detection area 4 is an area other than the specific area and the second period when the detection area 4 is the specific area, the background data D2 used in the second period is corrected based on the temperature change amount generated in the first period. In this case, in the first period when the detection area 4 is an area other than the specific area, the background data D2 corresponding to the specific area is not updated, so due to the temperature change generated in the first period, the background data D2 used in the second period may be deviated. In order to reduce this deviation, the background correction unit 13 corrects the background data D2 in the second period when the detection area 4 is the specific area based on the temperature change amount in the first period when the detection area 4 is an area other than the specific area.

In addition, the "temperature change amount" mentioned in the present disclosure means the change amount when the temperature changes in a certain period. For example, the temperature change amount in the first period is the difference between the temperature at the start point of the first period and the temperature at the end point of the first period.

Here, as described above, the specific area is not fixed, and the specific area changes depending on which of the first area A1, the second area A2, and the third area A3 is focused on. Thus, for example, when the first area A1 is a "specific area", the period during which the detection area 4 is the second area A2 and the period during which the detection area 4 is the third area A3 both become the first period, and the period during which the detection area 4 is the first area A1 becomes the second period. Similarly, when the second area A2 is a "specific area", the period during which the detection area 4 is the first area A1 and the period during which the detection area 4 is the third area A3 both become the first period, and the period during which the detection area 4 is the second area A2 becomes the second period. When the third area A3 is a "specific area", the period during which the detection area 4 is the first area A1 and the period during which the detection area 4 is the second area A2 both become the first period, and the period during which the detection area 4 is the third area A3 becomes the second period.

Here, the temperature change amount used in the background correction unit 13 is a representative value of the change amount of the temperature values of multiple pixels of the background data D2 during the period when the detection area 4 is an area other than the specific area. The "representative value" mentioned in the present disclosure includes an average value, a most frequent value, and a central value, etc. In the present embodiment, as an example, it is assumed that the representative value is the average value. That is, as described above, the output data D1 and the background data D2 are each image data containing multiple pixels whose temperature values are respectively used as pixel values. Therefore, in the present embodiment, the background correction unit 13 uses the average value of the change amount of the temperature values of all pixels constituting the background data D2 during the period (the first period) when the detection area 4 is an area other than the specific area as the temperature change amount generated during the period (the first period).

The background update unit 14 updates the background data D2. The background update unit 14 updates the background data D2 corresponding to the detection area 4 at any time while the detection area 4 is in the same area. That is, while the detection area 4 stops at any area of the plurality of areas A1 to A3, the background update unit 14 updates the background data D2 corresponding to the area at any time. The processing involved in the update of the background data D2 in the background update unit 14 is described in detail in the column "(2.3) Action".

In this embodiment, the determination unit 11 determines the presence or absence of the object 5 multiple times while the detection area 4 is in the same area, and the background update unit 14 updates the background data D2 each time the determination unit 11 determines the presence or absence of the object. That is, while the detection area 4 is in the same area, the number of times the determination unit 11 determines the presence or absence of the object 5 and the number of times the background update unit 14 updates the background data D2 become the same number.

The acquisition unit 15 is connected to the temperature sensor 2 and acquires the output data D1 from the temperature sensor 2. In the present embodiment, the temperature sensor 2 outputs a thermal image as the output data D1, so the acquisition unit 15 acquires the output data D1 including the thermal image. Here, the frequency at which the acquisition unit 15 acquires the output data D1 is determined, for example, by the frame rate of the temperature sensor 2. That is, if the frame rate of the temperature sensor 2 is 10 [fps] as an example, the acquisition unit 15 acquires the output data D1 at intervals of 0.1 [s].

The background storage unit 16 includes, for example, a nonvolatile memory, and stores the background data D2. The background storage unit 16 stores the background data D2 in correspondence with the first area A1, the second area A2, and the third area A3. That is, in the present embodiment, the background data D2 is stored in the background storage unit 16 according to each area (the first area A1, the second area A2, or the third area A3) that is a candidate for the detection area 4.

When the background data D2 is corrected by the background correction unit 13, the background data D2 stored in the background storage unit 16 is rewritten as the corrected background data D2. For example, when the background data D2 corresponding to the first area A1 is corrected by the background correction unit 13, the background data D2 corresponding to the first area A1 stored in the background storage unit 16 is rewritten as the corrected background data D2.

Similarly, when the background data D2 is updated by the background update unit 14, the background data D2 stored in the background storage unit 16 is rewritten as the updated background data D2. For example, when the background data D2 corresponding to the first area A1 is updated by the background update unit 14, the background data D2 corresponding to the first area A1 stored in the background storage unit 16 is rewritten as the updated background data D2.

Therefore, the latest background data D2, that is, the corrected or updated background data D2, is always stored in the background storage unit 16.

In addition, based on the output data D1 of the temperature sensor 2, that is, the thermal image acquired by the acquisition unit 15, it is possible not only to determine the presence or absence of the object 5, but also to estimate the temperature of the space, floor, wall, ceiling, etc. in the detection area 4. Therefore, the object detection system 1 can also output information related to the temperature of the space, floor, wall, ceiling, etc. in the detection area 4 to the air conditioner 3 in addition to or instead of the presence or absence of the object 5. In this case, the air conditioner 3 can operate based on the temperature of the space, floor, wall, ceiling, etc. in the detection area 4.

(2.3) Action

Next, the operation of the object detection system 1 will be described with reference to Fig. 2A to Fig. 4B. Here, the following case will be described, that is, in the sensor system 20 (including the object detection system 1) used for the air conditioning system 30, as shown in Fig. 2A, a "person" existing in the room 40 where the air conditioner 3 is installed is detected as the object 5.

The object detection system 1 determines the presence or absence of the object 5 in the detection area 4 by the determination unit 11 based on the comparison result of the output data D1 of the temperature sensor 2 and the background data D2 acquired by the acquisition unit 15. Here, the object detection system 1 switches the detection area 4 between the plurality of areas (the first area A1, the second area A2, and the third area A3) by the switching unit 12, and determines the presence or absence of the object 5 by the determination unit 11 for each of these plurality of areas A1 to A3. That is, FIG. 2A is a schematic top view showing the state of switching the detection area 4 between the first area A1, the second area A2, and the third area A3, and in particular, shows the state of the detection area 4 being in the first area A1. Here, as an example, the object detection system 1 sequentially switches the detection area 4 in the order of the first area A1, the second area A2, the first area A1, the third area A3, the second area A2, the first area A1, ..., and determines the presence or absence of the object 5.

The object detection system 1 acquires a thermal image as output data D1 from the temperature sensor 2 through the acquisition unit 15 while the detection area 4 is fixed to any one of the multiple areas A1 to A3, and compares the output data D1 with the background image D2. FIG2B shows the thermal image acquired as output data D1 by the acquisition unit 15 when the detection area 4 is respectively in the first area A1, the second area A2, and the third area A3 in the example of FIG2A. In FIG2B, the output data D1 acquired in the first area A1 is indicated as "center", the output data D1 acquired in the second area A2 is indicated as "right", and the output data D1 acquired in the third area A3 is indicated as "left". That is, as shown in FIG2B, in the output data D1 when the detection area 4 is in the first area A1, the temperature value (pixel value) of the pixel P1 corresponding to the object 5 (person) in the first area A1 becomes larger. In FIG2B, the shaded area represents the pixels whose temperature values exceed the given value. Likewise, as shown in FIG. 2B , in the output data D1 when the detection area 4 is in the second area A2 , the temperature value (pixel value) of the pixel P1 corresponding to the object 5 (person) in the second area A2 becomes larger.

In order to extract the pixel P1 corresponding to the object 5 (person) as described above, the output data D1 and the background data D2 are compared in the object detection system 1. Basically, as described above, the object detection system 1 uses the output data D1 of the temperature sensor 2 in the absence of the object 5 as the background data D2. Therefore, as shown in FIG. 3A and FIG. 3B, the object detection system 1 acquires the output data D1 of the temperature sensor 2 in the absence of the object 5 as the background data D2 through the acquisition unit 15. FIG. 3A is a schematic top view showing the state in which the detection area 4 switches between the first area A1, the second area A2, and the third area A3, and in particular shows the state in which the detection area 4 is in the first area A1. FIG. 3B shows a thermal image acquired as the background data D2 by the acquisition unit 15 when the detection area 4 is in the first area A1, the second area A2, and the third area A3, respectively, in the example of FIG. 3A.

Then, the object detection system 1 calculates differential data by taking the difference between the output data D1 and the background data D2, and compares the calculated differential data with the threshold value, thereby determining the presence or absence of the object 5 in the detection area 4. In the present embodiment, the output data D1 and the background data D2 are both thermal images, so the determination unit 11 generates differential data by taking the difference for each pixel. In other words, the differential data includes image data that uses the differential value between the same pixel of the output data D1 and the background data D2 as the pixel value. The determination unit 11 determines that the object 5 is "present" based on the fact that the differential data exceeds the threshold value.

As an example, FIG. 4B schematically shows the Y1 line section in the output data D1 shown in FIG. 4A. That is, it is assumed that by extracting the pixel P1 of one row along the horizontal axis (X axis) of the output data D1 shown in FIG. 4A, the temperature distribution shown in FIG. 4B is obtained. In this case, as shown in FIG. 4B, the object detection system 1 calculates the differential data by taking the difference between the output data D1 and the background data D2, and compares the calculated differential data with the threshold value Vth1, thereby determining the presence or absence of the object 5 in the detection area 4. Here, the determination unit 11 determines that the object 5 "exists" based on the fact that the differential data exceeds the threshold value Vth1. That is, in the example of FIG. 4B, in the shaded area of the data (shown by the dotted line) in the output data D1 that exceeds the background data D2 plus the threshold value Vth1, the differential data exceeds the threshold value Vth1. In the determination unit 11, it is determined that the object 5 exists in the shaded area, that is, a "person" exists.

Here, in order to distinguish between the object 5 and the heat source other than the object 5, the judgment unit 11 may also use at least one of the size, shape and pixel value (temperature value) of the pixel (shadow area) whose differential data exceeds the threshold value Vth1 to judge whether there is the object 5 (person).

FIG. 5 to FIG. 7 are flowcharts showing an example of the operation of the object detection system 1 according to the present embodiment. In particular, in FIG. 5 and FIG. 6, the processing is distinguished and recorded according to which of the multiple areas A1 to A3 the detection area 4 is located. In FIG. 5 and FIG. 6, the processing when the detection area 4 is the first area A1 is recorded in the "center" column, the processing when the detection area 4 is the second area A2 is recorded in the "right" column, and the processing when the detection area 4 is the third area A3 is recorded in the "left" column.

As shown in FIG5 , after the object detection system 1 is started, it first acquires the background data D2 corresponding to the third area A3 (S1). Then, the object detection system 1 performs a switching process of switching the detection area 4 from the third area A3 to the first area A1 (S2), and acquires the background data D2 corresponding to the first area A1 (S3). Then, the object detection system 1 performs a switching process of switching the detection area 4 from the first area A1 to the second area A2 (S4), and acquires the background data D2 corresponding to the second area A2 (S5). Thus, in the object detection system 1, the acquisition of the background data D2 corresponding to the first area A1, the second area A2 and the third area A3 is completed. The acquired background data D2 is stored in the background storage unit 16 in correspondence with the first area A1, the second area A2 and the third area A3, respectively.

Then, the object detection system 1 performs a switching process (S6) of switching the detection area 4 from the second area A2 to the first area A1, and reads the background data D2 corresponding to the first area A1 from the background storage unit 16 (S7). Thereafter, the object detection system 1 performs the judgment process described later on the first area A1 (S8). Then, the object detection system 1 calculates the temperature change amount generated during the period when the detection area 4 is the first area A1 through the background correction unit 13 (S9). At this time, the background correction unit 13 calculates the average value (representative value) of the change amount of the temperature values of multiple pixels of the background data D2 during the period when the detection area 4 is the first area A1 as the "temperature change amount".

Then, the object detection system 1 performs a switching process (S10) of switching the detection area 4 from the first area A1 to the second area A2, and reads the background data D2 corresponding to the second area A2 from the background storage unit 16 (S11). Thereafter, the object detection system 1 performs a background correction process (S12) of correcting the background data D2 through the background correction unit 13. At this time, the specific area is the second area A2, so based on the temperature change amount generated during the period when the detection area 4 is an area other than the specific area (the first area A1), that is, the temperature change amount calculated by processing S9, the background data D2 corresponding to the second area A2 is corrected. Thereafter, the object detection system 1 performs a judgment process (S13) on the second area A2 using the corrected background data D2. Thereafter, the object detection system 1 calculates the temperature change amount generated during the period when the detection area 4 is the second area A2 through the background correction unit 13 (S14). At this time, the background correction unit 13 calculates, as the “temperature change amount”, an average value (representative value) of the changes in the temperature values of the plurality of pixels of the background data D2 during the period when the detection area 4 is the second area A2.

Then, the object detection system 1 performs a switching process (S15) of switching the detection area 4 from the second area A2 to the first area A1, and as shown in FIG6 , reads the background data D2 corresponding to the first area A1 from the background storage unit 16 (S16). Thereafter, the object detection system 1 performs a background correction process (S17) of correcting the background data D2 through the background correction unit 13. At this time, the specific area is the first area A1, so based on the temperature change amount generated during the period when the detection area 4 is an area other than the specific area (the second area A2), that is, the temperature change amount calculated by processing S14, the background data D2 corresponding to the first area A1 is corrected. Thereafter, the object detection system 1 performs a judgment process (S18) on the first area A1 using the corrected background data D2. Thereafter, the object detection system 1 calculates the temperature change amount generated during the period when the detection area 4 is the first area A1 through the background correction unit 13 (S19). At this time, the background correction unit 13 calculates, as the “temperature change amount”, an average value (representative value) of the changes in the temperature values of the plurality of pixels of the background data D2 during the period when the detection area 4 is the first area A1.

Then, the object detection system 1 performs a switching process (S20) to switch the detection area 4 from the first area A1 to the third area A3, and reads out the background data D2 corresponding to the third area A3 from the background storage unit 16 (S21). Thereafter, the object detection system 1 performs a background correction process (S22) to correct the background data D2 through the background correction unit 13. At this time, the specific area is the third area A3, so based on the temperature change amount generated during the period when the detection area 4 is an area other than the specific area (the first area A1), that is, the temperature change amount calculated by processing S19, the background data D2 corresponding to the third area A3 is corrected. Thereafter, the object detection system 1 performs a judgment process (S23) on the third area A3 using the corrected background data D2.

Thereafter, by repeatedly performing the same processing, the object detection system 1 switches the detection area 4 between the plurality of areas A1 to A3 and determines the presence or absence of the target object 5 in each of the plurality of areas A1 to A3.

FIG7 shows an overview of each judgment process (S8, S13, S18, S23). That is, in the judgment process, the object detection system 1 first obtains the latest thermal image from the temperature sensor 2 as output data D1 (S101). Then, the object detection system 1 calculates differential data by taking the difference between the output data D1 and the background data D2 (S102). Then, the object detection system 1 compares the calculated differential data with the threshold value to determine the presence or absence of the object 5 (person) in the detection area 4 (S103).

Then, the object detection system 1 executes the update of the background data D2 through the background update unit 14 (S104). At this time, the background update unit 14 updates the background data D2 to be close to the output data D1. Specifically, the background update unit 14 generates differential data by taking the difference between the output data D1 and the background data D2 for each pixel, and multiplies the differential data by a given ratio (for example, a few %) of the update data and adds it to the background data D2, thereby updating the background data D2. However, in the case where it is determined by processing S103 that there is an object 5, for the output data D1, the area where the object 5 exists is excluded and used for the update of the background data D2. In other words, only the pixels in the area where the object 5 does not exist in the output data D1 are used for the update of the background data D2. As a result, in the case where the temperature of the room 40 gradually changes, the background data D2 is updated to track its temperature change.

Then, the object detection system 1 determines whether a given time has passed since the start of the judgment process (S105). At this time, if the given time has not passed (S105: No), the process returns to S101, and if the given time has passed (S105: Yes), the judgment process ends. Thus, the above-mentioned processes S101 to S104 are repeated until the given time has passed.

According to the operation of the object detection system 1 described above, the background correction unit 13 corrects the background data D2 corresponding to the specific area based on the temperature change amount during the period when the detection area 4 is an area other than the specific area. Therefore, during the period when the detection area 4 is an area other than the specific area, for example, when the temperature of the room 40 is increased by the air conditioner 3, the reliability (detection accuracy) of the detection of the object 5 in the object detection system 1 is not easily reduced.

That is, as shown in FIG8 , by correcting the background data D2 based on the temperature change ΔT1, it becomes less likely to cause false detection of the object 5 or missed detection of the object 5. FIG8 , like FIG4B , schematically shows the Y1 line section in the output data D1 shown in FIG4A . In summary, for example, when the specific area is the first area A1, the background data D2 corresponding to the first area A1 is corrected by the amount of temperature change ΔT1 generated during the period when the detection area 4 is an area other than the specific area (first area A1). In the example of FIG8 , the background data D2' before correction is represented by an imaginary line (double-dotted dash line), and the background data D2 after correction is represented by a solid line. The judgment process is performed based on the corrected background data D2, so it becomes less likely to cause false detection of the object 5 or missed detection of the object 5.

9 is a flowchart showing the operation of the object detection system according to the comparative example. The object detection system according to the comparative example mentioned here is assumed to be a structure in which the background correction unit 13 is omitted from the object detection system 1 according to the present embodiment. In other words, the object detection system according to the comparative example has the same structure as the object detection system 1 according to the present embodiment except that the background correction unit 13 is omitted.

As shown in FIG9 , in the comparative example, except that there is no temperature change amount calculation process (S9, S14, S19 in FIG5 and FIG6 ) and background correction process (S12, S17, S22 in FIG5 and FIG6 ), the same operation as the object detection system 1 involved in the present embodiment can be achieved. That is, the process "Sc(α)" (α is 1 to 23) in FIG9 corresponds to the process "S(α)" (α is 1 to 23) in FIG5 and FIG6 .

According to the object detection system involved in the comparative example, the detection area 4 switches between multiple areas A1 to A3, so during the period when the area outside the specific area is set as the detection area 4, the background data D2 corresponding to the specific area is not updated. Therefore, for example, in the case where the specific area is the first area A1, during the period when the area outside the specific area (the second area A2) is set as the detection area 4, the background data D2 corresponding to the specific area is not updated. Therefore, for example, as shown in FIG. 10A, as a result of the temperature rise during the period when the area outside the specific area (the second area A2) is set as the detection area 4, the differential data of the output data D1 and the background data D2 may exceed the threshold value regardless of the presence or absence of the object 5. As a result, even if there is no object 5, it will be judged that the object 5 "exists", resulting in a false detection.

In addition, in the object detection system involved in the comparative example, the background data D2 can also be re-acquired instead of the process (Sc11, Sc16, Sc21) of reading the background data D2. In this case, the background data D2 is re-acquired every time the detection area 4 switches between the multiple areas A1 to A3, so during the period when the area outside the specific area is set as the detection area 4, there is a possibility of missed detection of the object 5 (person) intruding into the specific area. That is, for example, as shown in FIG. 10B, there is a possibility that the object 5 (person) intruding into the specific area (the first area A1) during the period when the area outside the specific area (the second area A2) is set as the detection area 4 cannot be detected.

In contrast, in the object detection system 1 according to the present embodiment, the background correction unit 13 corrects the background data D2 corresponding to the specific area based on the temperature change during the period when the detection area 4 is an area other than the specific area, so that false detection and missed detection are not likely to occur. Therefore, in the present embodiment, there is an advantage that the reliability (detection accuracy) of the detection of the object 5 in the object detection system 1 is not likely to decrease even if the detection area 4 switches between the multiple areas A1 to A3.

(3) Modification

Embodiment 1 is only one of various embodiments of the present disclosure. Embodiment 1 can be modified in various ways according to design, etc. as long as the purpose of the present disclosure can be achieved. In addition, the same function as the object detection system 1 involved in Embodiment 1 can also be embodied by an object detection method, a program, or a non-volatile recording medium recording a program. The object detection method involved in one embodiment has a switching process (refer to S2, S4, S6, S10, S15, S20 of Figures 5 and 6), a judgment process (refer to S8, S13, S18, S23 of Figures 5 and 6), and a background correction process (refer to S12, S17, S22 of Figures 5 and 6). The switching process is a process of switching the detection area 4 between a plurality of areas A1 to A3 including at least a specific area. The judgment process is a process of judging the presence or absence of the object 5 in the detection area 4 based on the differential data between the output data D1 of the temperature sensor 2 and the background data D2. The temperature sensor 2 detects the temperature of the detection area 4. The background data D2 corresponds to the plurality of areas A1 to A3, respectively. The background correction process is a process for correcting the background data D2 corresponding to the specific area based on the temperature change amount during the period when the detection area 4 is an area other than the specific area. In addition, a program according to one embodiment is a program for causing a computer system to execute the above-mentioned object detection method.

The following lists modifications of Embodiment 1. The modifications described below can be applied in combination as appropriate.

In the object detection system 1, as shown in FIG. 11A to FIG. 11C, the areas A1 to A3 that may become the detection area 4 may also be adjustable. Specifically, in FIG. 11A, among the three areas obtained by dividing the space in the room 40 into three parts in a plan view, the central area becomes the first area A1, the area on the right becomes the second area A2, and the area on the left becomes the third area A3 when viewed from the temperature sensor 2. On the other hand, as shown in FIG. 11B, when the air conditioner 3 is set at the corner of the left side of the room 40 in a plan view, the central first area A1 is adjusted to be tilted to the right relative to the front of the air conditioner 3. As shown in FIG. 11C, when the air conditioner 3 is set at the corner of the right side of the room 40 in a plan view, the central first area A1 is adjusted to be tilted to the left relative to the front of the air conditioner 3. As a result, in the object detection system 1, the first area A1 can be directed toward the center of the room 40 regardless of the position of the air conditioner 3, and most of the room 40 can be used as the detection area 4.

In addition, in the modified examples of Figures 11A to 11C, the time that the detection area 4 is fixed to the multiple areas A1 to A3 is different according to the areas A1 to A3. In short, the switching unit 12 performs the switching of the detection area 4 at intervals of a given time, so the detection area 4 is fixed to each area A1 to A3 at given intervals. Here, the given time is set separately according to the first area A1, the second area A2, and the third area A3, so that the time that the detection area 4 is fixed to the multiple areas A1 to A3 is different according to the areas A1 to A3. In particular, with respect to the first area A1 corresponding to the center of the room 40, it is preferred that the given time is set longer than that of the second area A2 and the third area A3. Thus, the object detection system 1 can focus on detecting the presence or absence of the object 5 (person) with respect to the first area A1 where the possibility of the existence of the object 5 (person) is high.

The object detection system 1 in the present disclosure includes a computer system, for example, in the processing unit 10. The computer system uses a processor and a memory as hardware as the main structure. The processor executes the program recorded in the memory of the computer system, thereby realizing the function of the object detection system 1 in the present disclosure. The program can be pre-recorded in the memory of the computer system, provided through an electrical communication line, or recorded in a non-volatile recording medium such as a memory card, an optical disk, a hard disk drive, etc. that can be read by the computer system. The processor of the computer system includes one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits such as IC or LSI mentioned here are called differently according to the degree of integration, including integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, an FPGA (Field-Programmable Gate Array) programmed after the manufacture of the LSI, or a logic device that can realize the reconstruction of the bonding relationship inside the LSI or the reconstruction of the circuit division inside the LSI can also be adopted as a processor. A plurality of electronic circuits may be integrated into one chip or distributed across a plurality of chips. A plurality of chips may be integrated into one device or distributed across a plurality of devices.

In addition, it is not necessary for the object detection system 1 to integrate multiple functions in one housing, and the structural elements of the object detection system 1 may be dispersed in multiple housings. Furthermore, at least part of the functions of the object detection system 1, such as part of the functions of the processing unit 10, may be implemented through the cloud (cloud computing) or the like.

Furthermore, the object detection system 1 , the sensor system 20 , and the air conditioning system 30 are not limited to residential facilities, and may be introduced into non-residential facilities such as offices, stores, hospitals, schools, or nursing homes.

In addition, the object detection system 1 and the sensor system 20 are not limited to the air conditioning system 30, and can be used in, for example, a lighting control system or a room entry and exit management system.

In addition, the driving unit 21 is not a necessary component of the sensor system 20 and can be omitted as appropriate. When the driving unit 21 is omitted, the switching unit 12 can also switch the detection area 4 between the multiple areas A1 to A3 by selectively selecting and using the outputs of the multiple temperature sensors 2 corresponding to the multiple areas A1 to A3, for example.

In addition, the multiple regions that are candidates for the detection area 4 are not limited to the three regions A1 to A3, and may include more than four regions. Alternatively, the multiple regions that are candidates for the detection area 4 may also be two regions. When the detection area 4 switches only between the first region A1 and the second region A2, for example, when the first region A1 is a "specific region", the second region A2 becomes an "region outside the specific region". Similarly, when the second region A2 is a "specific region", the first region A1 becomes an "region outside the specific region". In this case, when the first region A1 is a "specific region", the period when the detection area 4 is the first region A1 becomes the first period and the third period, and the period when the detection area 4 is the second region A2 becomes the second period. Similarly, when the second region A2 is a "specific region", the period when the detection area 4 is the second region A2 becomes the first period and the third period, and the period when the detection area 4 is the first region A1 becomes the second period.

In addition, it is not a necessary structure of the object detection system 1 that the background update unit 14 updates the background data D2 every time the judgment unit 11 judges the presence or absence of the object. That is, during the period when the detection area 4 is in the same area, the number of times the judgment unit 11 judges the presence or absence of the object 5 and the number of times the background update unit 14 updates the background data D2 may be different from each other.

(Implementation Method 2)

The object detection system 1 according to this embodiment differs from the object detection system 1 according to Embodiment 1 in the method of calculating the temperature change amount used by the background correction unit 13. Hereinafter, the same configurations as those in Embodiment 1 are denoted by the same reference numerals and description thereof is omitted as appropriate.

In the first structural example of the present embodiment, as shown in FIG12 , it is assumed that the first area A1 and the second area A2 or the third area A3 overlap in the overlapping area A10. That is, in the first area A1 and the second area A2, a part of each other overlaps in the overlapping area A10. Similarly, in the first area A1 and the third area A3, a part of each other overlaps in the overlapping area A10.

In this case, the temperature change amount used by the background correction unit 13 is a representative value (e.g., average value) of the change amount of the temperature value of the pixel corresponding to the repeated area A10 among the multiple pixels of the background data D2 during the period when the detection area 4 is an area other than the specific area. That is, the temperature change amount is a representative value of the change amount of the temperature value of the pixel in the repeated area A10 among the multiple pixels of the background data D2 during the period when the detection area 4 is an area other than the specific area and is an area that overlaps with the specific area in the repeated area A10. For example, if the specific area is the second area A2, the representative value of the change amount of the temperature value of the pixel in the repeated area A10 among the multiple pixels of the background data D2 during the period when the detection area 4 is the first area A1 is used as the temperature change amount. In addition, if the specific area is the third area A3, the representative value of the change amount of the temperature value of the pixel in the repeated area A10 among the multiple pixels of the background data D2 during the period when the detection area 4 is the first area A1 is used as the temperature change amount.

According to the first configuration example, the temperature change occurring in the overlapping region A10 which is a part of the specific region is reflected in the correction of the background data D2 corresponding to the specific region, so the accuracy of the correction of the background data D2 is improved.

In addition, in the second structural example involved in the present embodiment, the temperature change amount used by the background correction unit 13 is a value reflecting the distribution of temperature values in the background data D2 during the period when the detection area 4 is an area other than the specific area. That is, when the background data D2 changes with a specific distribution during the period when the detection area 4 is an area other than the specific area, the distribution is reflected in the temperature change amount.

As an example, assume the following situation, that is, during the period when the detection area 4 is the first area A1, the temperature in the room 40 rises, and the temperature rises significantly in the second area A2 compared to the third area A3. In this case, if it is assumed that the specific area is the second area A2 or the third area A3, the background data D2 changes as shown in FIG13A during the period when the detection area 4 is the area other than the specific area (the first area A1). In FIG13A, the background data D2 before the change during the period when the detection area 4 is the first area A1 is represented by an imaginary line (a double-dashed line), and the background data D2 after the change is represented by a solid line. From the distribution of temperature values in the background data D2 during the period when the detection area 4 is the area other than the specific area, it can be seen that the temperature rise of the area on the right side of the first area A1 (the second area A2) is greater than that of the area on the left side of the first area A1 (the third area A3). Therefore, the background correction unit 13 uses the temperature change amount ΔT1 to correct the background data D2 corresponding to the second area A2 , and uses the temperature change amount ΔT2 (<ΔT1 ) to correct the background data D2 corresponding to the third area A3 .

According to the second configuration example, the temperature distribution of the region other than the specific region is reflected in the correction of the background data D2 corresponding to the specific region, so the accuracy of the correction of the background data D2 is improved.

In addition, in the third structural example involved in the present embodiment, the temperature change amount used by the background correction unit 13 is a representative value of the change amount of the temperature value of the pixels other than the specific pixel among the plurality of pixels of the background data D2 during the period when the detection area 4 is the area other than the specific area. That is, it is not the change of the temperature value of all the pixels of the background data D2 during the period when the detection area 4 is the area other than the specific area that is reflected in the temperature change amount, but the change of the temperature value of the pixels other than a part of the pixels (specific pixels) is reflected in the temperature change amount.

As an example, assume the following situation, that is, during the period when the detection area 4 is the first area A1, for example, the television receiver 401 (refer to FIG. 2A) is turned on, and the television receiver 401 becomes a fixed heat source, thereby causing a temperature rise locally in the room 40. In this case, if it is assumed that the specific area is the second area A2 or the third area A3, the background data D2 changes as shown in FIG. 13B during the period when the detection area 4 is an area other than the specific area (the first area A1). In FIG. 13B, the background data D2 before the change during the period when the detection area 4 is the first area A1 is represented by an imaginary line (a double-dashed line), and the background data D2 after the change is represented by a solid line. In the background data D2 during the period when the detection area 4 is an area other than the specific area, it can be seen that a local temperature rise occurs due to the influence of the fixed heat source. Therefore, the temperature change amount ΔT1 used by the background correction unit 13 in the correction of the background data D2 corresponding to the second area A2 is a representative value (e.g., an average value) of the change amount of the temperature value of the pixels other than the specific pixels (the pixels in the range shown by Z1 in FIG. 13B ). Here, as an example, when a temperature value difference of a part of the pixels and the remaining pixels exceeds a predetermined value among the plurality of pixels constituting the background data D2, it is determined that a local temperature change has occurred in the part of the pixels, that is, the part of the pixels are the specific pixels.

According to the third configuration example, the influence of the fixed heat source in the specific area is not reflected in the correction of the background data D2 corresponding to the specific area, so the accuracy of the correction of the background data D2 is improved.

The configuration described in the second embodiment can be adopted in combination with the various configurations (including modified examples) described in the first embodiment as appropriate.

(Summarize)

As described above, the object detection system (1) involved in the first embodiment includes a switching unit (12), a judgment unit (11) and a background correction unit (13). The switching unit (12) switches the detection area (4) between a plurality of areas (A1 to A3) including at least a specific area. The judgment unit (11) judges the presence or absence of an object (5) in the detection area (4) based on a comparison result of the output data (D1) of the temperature sensor (2) that detects the temperature of the detection area (4) and the background data (D2) corresponding to each of the plurality of areas (A1 to A3). The background correction unit (13) corrects the background data (D2) corresponding to the specific area based on the temperature change (ΔT1) during the period when the detection area (4) is an area other than the specific area.

According to this method, the detection area (4) for detecting the temperature by the temperature sensor (2) is switched between the plurality of areas (A1 to A3) by the switching unit (12), so that the area of the detectable object (5) can be expanded compared to the case where the detection area (4) is fixed. That is, in the object detection system (1), the area of the detectable object (5) is not limited to the field of view of the temperature sensor (2), and the object (5) existing outside the field of view of the temperature sensor (2) can also be detected. In addition, in the object detection system (i), the background correction unit (13) corrects the background data (D2) corresponding to the specific area based on the temperature change (ΔT1) during the period when the detection area (4) is an area other than the specific area. Therefore, even if the detection area (4) is switched between the plurality of areas (A1 to A3), the reliability of the detection of the object (5) in the object detection system (1) is not easily reduced.

In the object detection system (1) according to the second aspect, in the first aspect, the output data (D1) and the background data (D2) are each image data including a plurality of pixels CP1) each having a temperature value as a pixel value.

According to this method, the presence or absence of the object (5) is determined based on the image data, so the reliability of detecting the object (5) is improved.

In the object detection system (1) involved in the third embodiment, under the second embodiment, the temperature change (ΔT1) is a representative value of the change in temperature values of multiple pixels (P1) with respect to background data (D2) during a period when the detection area (4) is an area other than a specific area.

According to this aspect, it is possible to improve the accuracy of correction of the background data (D2) corresponding to the specific area.

In the object detection system (1) involved in the fourth embodiment, under the second embodiment, the temperature change (ΔT1) is a representative value of the change in temperature values of pixels in the repeated area (A10) among multiple pixels (P1) of the background data (D2) during a period when the detection area (4) is an area outside the specific area and is an area in the repeated area (A10) that overlaps with the specific area, and the repeated area (A10) is a part of the specific area.

According to this aspect, it is possible to improve the accuracy of correction of the background data (D2) corresponding to the specific area.

In the object detection system (1) involved in the fifth aspect, in the second aspect, the temperature change (ΔT1) is a value reflecting the distribution of temperature values in the background data (D2) during the period when the detection area (4) is an area other than the specific area.

According to this aspect, it is possible to improve the accuracy of correction of the background data (D2) corresponding to the specific area.

In the object detection system (1) involved in the sixth embodiment, under the second embodiment, the temperature change (ΔT1) is a representative value of the change in temperature values of pixels other than the specific pixel among multiple pixels (P1) of the background data (D2) during the period when the detection area (4) is an area other than the specific area.

According to this aspect, it is possible to improve the accuracy of correction of the background data (D2) corresponding to the specific area.

In the object detection system (1) involved in the seventh aspect, in any one of the first to sixth aspects, the determination unit (11) determines the presence or absence of the object (5) a plurality of times while the detection area (4) is in the same area.

According to this method, it is possible to improve the detection accuracy of the object (5).

The object detection system (1) according to the eighth aspect further comprises, in the seventh aspect, a background updating unit (14) for updating background data (D2) each time the determining unit (11) determines the presence or absence of the object (5).

According to this method, it is possible to improve the detection accuracy of the object (5).

In the object detection system (1) according to a ninth aspect, in any one of the first to eighth aspects, the target object (5) is a moving object.

According to this method, the movement of the object (5) which is a moving object can be detected.

In the object detection system (1) according to a tenth aspect, in any one of the first to ninth aspects, the time during which the detection area (4) is fixed to each of the plurality of areas (A1 to A3) differs among the areas.

According to this aspect, the object (5) can be detected intensively in any of the plurality of areas (A1 to A3).

In the object detection system (1) according to the eleventh aspect, in any one of the first to tenth aspects, the plurality of areas (A1 to A3) include three or more areas.

According to this method, the area where the object (5) can be detected can be further expanded.

A sensor system (20) according to a twelfth aspect comprises the object detection system (1) according to any one of the first to eleventh aspects and a temperature sensor (2).

According to this method, the detection area (4) for detecting the temperature by the temperature sensor (2) is switched between the plurality of areas (A1 to A3) by the switching unit (12), so that the area of the detectable object (5) can be expanded compared to the case where the detection area (4) is fixed. That is, in the sensor system (20), the area of the detectable object (5) is not limited to the field of view of the temperature sensor (2), and the object (5) existing outside the field of view of the temperature sensor (2) can also be detected.

An air conditioning system (30) according to a thirteenth aspect comprises: the sensor system (20) according to the twelfth aspect; and an air conditioner (3) that operates based on an output of a determination unit (11).

According to this method, the detection area (4) for detecting the temperature by the temperature sensor (2) is switched between the plurality of areas (A1 to A3) by the switching unit (12), so that the area of the detectable object (5) can be expanded compared to the case where the detection area (4) is fixed. That is, in the air conditioning system (30), the area of the detectable object (5) is not limited to the field of view of the temperature sensor (2), and the object (5) existing outside the field of view of the temperature sensor (2) can also be detected.

The object detection method involved in the 14th mode includes switching processing, judgment processing and background correction processing. The switching processing is a processing for switching the detection area (4) between multiple areas (A1~A3) including at least a specific area. The judgment processing is a processing for judging the presence or absence of an object (5) in the detection area (4) based on the comparison result of the output data (D1) of the temperature sensor (2) detecting the temperature of the detection area (4) and the background data (D2) corresponding to each of the multiple areas (A1~A3). The background correction processing is a processing for correcting the background data (D2) corresponding to the specific area based on the temperature change (ΔT1) during the period when the detection area (4) is an area other than the specific area.

According to this method, the detection area (4) for detecting the temperature by the temperature sensor (2) is switched between the plurality of areas (A1 to A3) by a switching process, so that the area of the detectable object (5) can be expanded compared to the case where the detection area (4) is fixed. That is, in the above-mentioned object detection method, the area of the detectable object (5) is not limited to the field of view of the temperature sensor (2), and the object (5) existing outside the field of view of the temperature sensor (2) can also be detected.

The program according to the fifteenth aspect is a program for causing a computer system to execute the object detection method according to the fourteenth aspect.

According to this method, the detection area (4) for detecting the temperature by the temperature sensor (2) is switched between the plurality of areas (A1 to A3) by a switching process, so that the area of the detectable object (5) can be expanded compared to the case where the detection area (4) is fixed. That is, in the above-mentioned procedure, the area of the detectable object (5) is not limited to the field of view of the temperature sensor (2), and the object (5) existing outside the field of view of the temperature sensor (2) can also be detected.

The present invention is not limited to the above-described embodiment, and various structures (including modified examples) of the object detection system (1) according to the first embodiment and the second embodiment can be embodied by an object detection method and a program.

The configurations according to the second to eleventh aspects are not essential to the object detection system (1) and can be omitted as appropriate.

Symbol Description

1 Object detection system;

2 Temperature sensor;

3. Air conditioner;

4 detection area;

5. Object;

11. Judgment Department;

12 switching unit;

13 Background Correction Department;

14 Background Update Department;

20 sensor systems;

30 Air conditioning system;

Area A1 to A3;

D1 outputs data;

D2 background data;

ΔT1 is the temperature change.

Claims (14)

1. A sensor system comprising an object detection system and a temperature sensor, The temperature sensor is configured to be rotatable. The object detection system comprises: a switching unit that rotates the temperature sensor to switch the detection area between a plurality of areas including at least a specific area; a determination unit that determines the presence or absence of an object within the detection area based on a comparison result of output data of the temperature sensor that detects the temperature of the detection area and background data corresponding to each of the plurality of areas; and The background correction unit corrects the background data corresponding to the specific area during a period when the detection area is an area other than the specific area based on a temperature change amount of the background data corresponding to the specific area during a period when the detection area is an area other than the specific area. 2. The sensor system according to claim 1, wherein: The output data and the background data are each image data including a plurality of pixels each having a temperature value as a pixel value. 3. The sensor system according to claim 2, wherein: The temperature change amount is a representative value of the change amount of the temperature values of the plurality of pixels of the background data during a period in which the detection area is an area other than the specific area. 4. The sensor system according to claim 2, wherein: The temperature change amount is a representative value of the change amount of the temperature value of the pixels in the repeated area among the multiple pixels of the background data during the period when the detection area is an area outside the specific area and is an area in the repeated area that overlaps with the specific area, and the repeated area is a part of the specific area. 5. The sensor system according to claim 2, wherein: The temperature change amount is a value reflecting the distribution of the temperature value in the background data during a period when the detection area is an area other than the specific area. 6. The sensor system according to claim 2, wherein: The temperature change amount is a representative value of the change amount of the temperature value of pixels other than the specific pixel among the plurality of pixels of the background data during a period when the detection area is an area other than the specific area. 7. The sensor system according to any one of claims 1 to 6, wherein: The determination unit determines the presence or absence of the object a plurality of times while the detection area is in the same area. 8. The sensor system according to claim 7, wherein: The device further includes a background updating unit configured to update the background data each time the determining unit determines the presence or absence of the object. 9. The sensor system according to any one of claims 1 to 6, wherein: The object is a moving object. 10. The sensor system according to any one of claims 1 to 6, wherein: The time periods during which the detection areas are respectively fixed to the plurality of areas vary according to the areas. 11. The sensor system according to any one of claims 1 to 6, wherein: The plurality of regions include more than three regions. 12. An air conditioning system comprising: The sensor system according to any one of claims 1 to 11; and The air conditioner operates based on the output of the determination unit. 13. An object detection method comprising: Switching processing, rotating the temperature sensor to switch the detection area between a plurality of areas including at least the specific area; A determination process of determining whether or not there is an object in the detection area based on a comparison result of output data of the temperature sensor detecting the temperature of the detection area and background data corresponding to each of the plurality of areas; and The background correction process corrects the background data corresponding to the specific area during the period when the detection area is the specific area based on the temperature change amount of the background data corresponding to the specific area during the period when the detection area is the area other than the specific area. 14. A non-volatile recording medium having a program recorded thereon, the program being used to cause a computer system to execute the object detection method according to claim 13.