EP2060857A1

EP2060857A1 - Air conditioner

Info

Publication number: EP2060857A1
Application number: EP07806197A
Authority: EP
Inventors: Hirotoshi Yano; Shoji Mochizuki; Makoto Hirano; Akira Hidaka; Masayoshi Sato; Shintaro Watanabe; Hiroshi Kage; Takashi Matsumoto
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2006-09-07
Filing date: 2007-08-29
Publication date: 2009-05-20
Anticipated expiration: 2027-08-29
Also published as: EP2060857A4; JPWO2008029679A1; WO2008029679A1; JP5452550B2; CN101490479A; EP2060857B1; CN101490479B; JP4859926B2; JP2011208936A

Abstract

A control unit 101 installed in an indoor unit 10 makes a thermopile 11 scan, allows it to scan a temperature detection covering range so as to overlap a partial region of the temperature detection range of the thermopile 11 and allows it to detect temperatures in a state with the partial region overlapped. Or the control unit 101 allows multiple thermopiles 11 to obtain temperature information in the temperature detection covering range at one time in such a manner that partial regions of the temperature detection ranges of the multiple thermopiles 11 are overlapped. The control unit 101 obtains temperature information by continuously or periodically carrying out the temperature detection, and based on the time variation of temperature information obtained, determines that a human exists when the variation exceeds the human body detection threshold value and determines where the human exists. Furthermore, based on the human body detection information, the control unit 101 increases a human body existence value, and decrease the human body existence value when the human body is not detected. When a human body existence value becomes less than the absence determination threshold value, the control unit 101 determines the absence of a human body only at a place where motion was detected last time.

Description

[Technical Field]

The present invention relates to an air conditioner that is equipped with temperature detection means and detects a heat source to detect the existence of a human or a heat generating apparatus, and that can carry out comfortable control.

[Background Art]

In conventional air conditioners, there is known an inexpensive method for detecting a human body by using a lens to limit a detection range of a sensor unit of temperature detection means using a temperature detection element such as a thermopile and by finding out whether or not there is any temperature change that exceeds a predetermined value in each region while successively switching temperature detection regions by one temperature detection means (for example, see Patent Document 1).
In addition, there is known an infrared sensing device that successfully secures the infrared ray sensing time by adopting a stepping motor which makes an intermittent drive as a motor that makes temperature detection means utilizing one pyroelectric sensor perform scanning, improves the spatial resolution and temperature resolution by this, and can achieve downsizing and low cost (for example, see Patent Document 2).
Furthermore, there is known a human body detection device that measures a living space at one time by a plurality of thermopile elements disposed in a form of matrices, which correspond to plural regions configured by dividing the living space, finds out temperature of each region, and detects absence or presence of a human by the variation of temperature based on the difference from the reference temperature using thermistors (for example, see Patent Document 3).
There is shown a method for detecting a human body on the basis of changes of light intensity of each region detected by temperature detection means (thermopiles, pyroelectric sensor) which scan plural regions of an indoor space or on the basis of a state in which the light intensity in a detection area exceeds a certain threshold value (for example, see Patent Document 7).
In addition, there is a knownmethod to compute temperature changes for zones, control an air conditioner on the assumption that a human moves in a zone with large temperature changes, and predict that a human does not move and stands still in a zone in which the temperature change is small but the measurement difference from the surroundings is large (for example, see Patent Document 6).
In addition, there is a known method to determine the place with large temperature changes as the position where a human exists, by making a pyroelectric type infrared sensor repeatedly scan a covering region back and forth and comparing the previous temperature of the covering region with the present temperature (for example, see Patent Document 5).
In addition, there is shown a method to detect a human body at a time when the variation of illuminance with time exceeds a reference value only with respect to the action frequency specific to a human body, not by the use of temperature detection means but by the use of an illuminance sensor (for example, see Patent Document 4).

[Patent Document 1] Japanese Patent Application Publication (JP-B) No. 7-30938 (FIG. 8, line 33 of page 6 to line 6 of page 8)
[Patent Document 2] Japanese Patent Application Laid-Open (JP-A) No. 8-170930 (FIG. 1, FIG. 2, paragraphs 0015 and 0018)
[Patent Document 3] JP-A-2001-304655 (FIG. 4, FIG. 7, paragraphs 0035 to 0038)
[Patent Document 4] JP-A-8-29541 (FIG. 2, paragraph 0045)
[Patent Document 5] JP-A-8-271645 (FIG. 1, paragraphs 0030 and 0032)
[Patent Document 6] Japanese Patent No. 2792997 (FIG. 4, FIG. 5, and line 29 to line 44 of page 4 of the specifications]
[Patent Document 7] JP-B-6-75011 (FIGS. 7 and 9, line 38 to line 42 of page 11, line 22 to line 24 of page 13, and line 45 to line 46 of page 14).

[Disclosure of the Invention]

[Problem to be Solved by the Invention]

However, a conventional air conditioner shown in Patent Document 1 includes a switching mechanism such as a lens for limiting the detection range at a sensor unit of a temperature detector to determine a human detection area, but the mechanism is expensive and cannot be said practical for home electric appliances such as air conditioners, etc.
In addition, in the conventional air conditioners shown in Patent Documents 2, 3, and 6, the detection capability was degraded in a region of the end of a sensor detection section depending on sensor characteristics, and there was a possibility of failure to correctly detect high temperature in an area between detection sections (in the vicinity of the boundary). There is a method of using a sensor by masking the area other than the vicinity of the center part of the sensor detection section where correct detection can be carried out, but expenses for customizing each sensor to each product are generated and the advantages of using inexpensive sensors are lost.
Furthermore, in the event that an air conditioner using temperature detection means that can detect the human body independently of the illuminance detects a human body, when the ambient temperature reaches the vicinity of 33°C which is understood to be the human radiation heat temperature, the air conditioner is unable to distinguish the ambient temperature from the human radiation heat and can not detect the human body.
When the human body is detected by the use of temperature detection means, the air conditioner is susceptible to noise of heat-generating apparatus and is likely to make false detection. Furthermore, once the air conditioner makes false detection, it is unable to determine the absence of a human, continues to make false detection to detect a substance as a human body, and consumes unrequired electric power by controlling air-stream operation or continuing operation in vain.
In a conventional air conditioner shown in Patent Document 7, there is no measures against heat sources and the heat sources are certain to be falsely detected. That is, the substance in the vicinity of human body temperature is falsely detected. In addition, once false detection occurrs, false detection continues thereafter. Consequently, absence is falsely determined.
In addition, a method to determine absence at a time when time passed is shown, too, but the whole room is scanned again to detect a human body by the same method and the heat source is falsely detected again as a human body, so that the absence is falsely determined.
The present invention has been made in view of the above-mentioned situations, and relates to an air conditioner that can accurately detect temperature by inexpensive temperature detection means even for the edge portion of the detection covering section of a sensor where heat information is difficult to obtain, that accurately determines the absence or presence of heat sources to detect the existence of a human, etc., and that can achieve comfortable control.

[Means for solving the problem]

The air conditioner according to the present invention includes temperature detection means that detects temperature while scanning a temperature detection covering range;
a temperature detection means drive circuit that drives the temperature detection means; and
a control unit that controls the temperature detection means drive circuit,
wherein the control unit directs the temperature detection means drive circuit to allow the temperature detection means to scan in such a manner as to overlap a partial region of the temperature detection range of the temperature detection means, so as to detect temperature by overlapping the partial region.
Note that the heat sources referred to here collectively means heat generators such as human body, heat-generating apparatus, etc.

[Effect of the Invention]

According to the present invention, even if the temperature detection means provides poor temperature detection accuracy at the end portion of the temperature detection range and is unable to accurately detect heat sources at the portion, the temperature detection means is allowed to scan in such a manner that the partial region of the temperature detection range is overlapped so as to detect temperature by overlapping the partial region, and therefore can secure satisfactory temperature detection accuracy by overlapping detection of the end portion of the range. This eliminates a portion where detection is degraded even if the kind of high-accuracy sensor, etc. is not chosen and permits accurate temperature detection and heat source detection.

[Brief Description of the Drawings]

FIG. 1 is an illustration that shows a first embodiment of the present invention.
FIG. 2 is a block diagram of an indoor unit 10 in the first embodiment.
FIG. 3 is a general block diagram with primary emphasis placed on the configuration of a control unit 101 in FIG. 2.
FIG. 4 is an illustration that shows the detection range and inspection method of temperature detection means (thermopile).
FIG. 5 is an illustration that shows grouping of regions according to detection temperature of temperature detection means (thermopile).
FIG. 6 is a flow chart that shows a human body detection method of the first embodiment of the present invention.
FIG. 7 is a flow chart that shows the continuation of FIG. 6.

[Description of reference numerals]

1: Air conditioner
10: Indoor unit
11: Thermopile
12: Thermistor
20: Outdoor unit
21: Thermistor
101: Control unit
102: Thermopile drive circuit
103: Fan drive circuit
104: Fan motor
105: Fan
106: Louver drive circuit
107: Louver drive motor
108: Louver
109: Thermopile drive motor
1003: Comparison unit
1004: A/D converter unit
1005: Temperature converter unit
1006: Human body detection unit
1007: Wind direction determining unit
1008: Wind velocity determining unit
1009: Scanning direction determining unit

[Best mode for carrying out the Invention]

In each of the following embodiments, the phrase "human body" may read "human" or "heat source."

First Embodiment

FIG. 1 is an illustration that shows the general configuration of an air conditioner 1 which shows a first embodiment of the present invention. The air conditioner 1 includes an indoor unit 10 and an outdoor unit 20. The indoor unit 10 includes a thermopile (infrared sensor) 11 as temperature detection means (temperature detector) in addition to regular devices required as an air conditioner indoor unit. As temperature measuring means (temperature measuring device) that measures reference temperature of the thermopile 11, a thermistor 12 is disposed close to the cold junction of the thermopile 11. Note that the thermopile 11 may consist of multiple pieces or one piece so that a partial region of an air-conditioning scheduled range (hereinafter also called a detection covering range) can be detected or may be configured in a matrix so that the whole area of the air-conditioning scheduled range can be simultaneously detected.
On the other hand, the outdoor unit 20 is equipped with regular devices necessary as an air-conditioning outdoor unit as well as with a thermistor 21 as outside temperature measuring means. In place of the thermistors 12 and 21, other temperature sensors may be used.
FIG. 2 is a block diagram of an indoor unit 10 in the first embodiment of the present invention, and the outdoor unit 10 includes a heat exchanger 13, thermopile drive circuit 102, thermopile drive motor 109, fan drive circuit 103, fan motor 104, fan 105, louver drive circuit 106, louver drive motor 107, louver 108, and others in addition to the thermopile 11 and the thermistor 12. In the event that there is no need of making the thermopile 11 scan, the thermopile drive circuit 102 and the thermopile drive motor 109 are not required. In addition, the "louver" may read "wind direction adjusting plate" or "flap."
The indoor unit 10 further includes a control unit (controller) 101 that works on each device of thermopile 11, thermistor 12, temperature detection means drive circuit 102, and fan drive circuit 103, and controls their operations. The control unit 101 imports (takes in) the information which thermopile 11 and thermistor 12 obtain and computes absence or presence and the position of a heat source based on these pieces of information. In this embodiment, the detected temperature imported by the thermopile 11 is converted into a thermal pixel image (also simply called a thermal image) and stored. The control unit 101 which achieves the above-mentioned operations includes a microcomputer to which predetermined operations are programmed.
FIG. 3 is a general block diagram focused on the configuration of the control unit 101. In FIG. 3, the control unit 101 includes a comparing unit 1003, A/D converter 1004, temperature converter 1005, human body detecting unit 1006, wind direction determining unit 1007, wind velocity determining unit 1008, and scanning direction determining unit 1009. However, in the event that there is no need of making the thermopile 11 scan, the scanning direction determining unit 1009 is not required.
Thereafter, the detection means including the human body detecting unit 1006, for detecting presence and absence of a heat generator may be collectively called a heat source detection unit, too.
Next, the operation of the air conditioner 1 will be described. The detected value of the thermopile 11 is imported into the control unit 101 via the amplifier circuit 1001 at predetermined intervals or continuously. In addition, the detected value (or measured value) of the thermistor 12 serves as a reference value for the detected value of the thermopile 11, and it is imported by the control unit 101 via the amplifier circuit 1002 at predetermined intervals or continuously.
The comparing unit 1003 compares the value detected by the thermopile 11 with the value detected by the thermistor 12 and outputs the difference. This difference (potential difference) is converted into digital signals by the A/D converter 1004. The temperature converter 1005 converts the digital potential difference signals to temperature information.
The human body detecting unit 1006 determines that a human body exists there, in the event that the difference between the previous temperature information and the present temperature information exceeds the preset human body detection threshold value.
In the event that the human body is detected by the human body detecting unit 1006, the wind direction determining unit 1007 determines the direction (angle) of the louver 108 when it receives a notice of the human detection information that indicates the human body existing position. The wind direction determining unit 1007 controls the louver drive circuit 106 with the determined louver 108 direction used as a command value. By this, a command is sent from the louver drive circuit 106 to the louver drive motor 107, which is a stepping motor, and the louver 108 direction is controlled.
Furthermore, in the event that a human body is detected by the human body detecting unit 1006, the wind velocity determining unit 1008 determines the wind velocity (or rotating speed) of the fan 105 when it receives a notice of the human body detection information. The wind velocity determining unit 1008 controls the fan drive circuit 103 with the determined wind velocity used as a command value. By this, a command is sent from the fan drive circuit 103 to the fan motor 104, and the fan motor 104 rotates the fan 105 at a rotating speed that corresponds to the command value and wind is sent out from the fan 105.
Similarly, in the event that the control unit 101 determines the heat source as heat generating device such as computer server, etc. on the basis of the threshold values that correspond to various heat generating devices, the control unit 101 cools the heat-generating device on the basis of the predetermined setting or air-conditions to prevent it from stopping due to overheating.
In the air conditioner of this embodiment, the control unit 101 periodically detects the temperature of the detection covering range by the use of the thermopile 11. In the event that the thermopile 11 installed detects only part of the detection covering range, the control unit 101 drives a stepping motor to allow the thermopile 11 to scan and allows it to detect temperature at each predetermined point, so as to detect temperatures of all the regions of the detection covering range.
In such event, the control unit 101 allows the thermopile 11 to scan in such a manner that the thermopile 11 detects temperatures, respectively, by successively overlapping part of a temperature detection range in which the thermopile 11 detects temperature at one time. Examples of the mode of overlapping temperature detection ranges capable of temperature detection include overlapping the ranges shifted by 1/2. Note that the amount of overlapping the temperature detection range of the thermopile 11 may be suitably determined in accordance with the temperature detection accuracy. By doing this, even in the case of temperature information at the end portion of the temperature detection range of the thermopile 11, the accuracy of detected temperature can be increased by the effect of overlapped measurements, and interference factors such as noise, etc. are dispersed, scarcelyexertingdetrimental effects on the temperature information. Consequently, it is possible to prevent deterioration of the accuracy at the end portions of the temperature detection range of the thermopile 11. The accuracy would be otherwise degraded if no measures are taken. In addition, because the temperature can be detected by the use of the sensor center part, highly accurate temperature detection is possible with an inexpensive sensor.
The values imported by successive overlapping as described above may be used as they are, but in the event that the position of the detection covering range is prescribed on the basis of the range where the thermopile 11 can detect temperature at one time, the detection range is shifted by 1/2. Therefore, in the event that the control unit 101 controls the air-conditioning air stream, etc., positional compensation such as coordinate transformation, etc. is necessary. In addition, temperatures of detected sections where the temperature detection range is overlapped and the imported value is overlapped may be averaged.
Note that in the event that the thermopile 11 detects temperature in the vicinity of human body radiation heat temperature with respect to the ambient temperature of the place where the thermopile 11 desires to detect a human body, it is desirable that the control unit 101 temporarily drives a fan 105 and allows air-conditioning control to take place until temperature lowers to a level in which the human body can be detected, or the control unit 101 identifies a place with a high probability of human body existence from one or more places detected, drives the louver 108 and the fan 105 to allow them to carry out air-conditioning control with a focus on the identified place, and resume human body detection after the ambient temperature reaches a level at which the human body can be detected.
In a casewhere still higher accuracy temperature detection is required, allowing the control unit 101 to detect temperature at each point where the temperature detection ranges of the thermopile 11 overlaps by 3/4 can still more improve the accuracy of the detected temperature.
Referring now to FIGS. 6 and 7 which show flow charts for showing the human body detection method, the human body detection operation of the air conditioner 1 will be described.
In Step S1 to S4 of FIG. 6, the control unit 101 utilizes the thermopile 11 and imports temperature information of the air-conditioning scheduled space (room) at predetermined intervals. In S5 and S6, the portions assumed to be the same temperature zone are grouped on the basis of the temperature information imported by the use of thermal pixel display as shown in FIG. 5. Then, in Step S7, the control unit 101 compares sequential temperature information obtained, such as the first temperature information T1, next temperature information T2, following temperature information T3, etc., and detects the portions of the values within a range in which the temperature difference is assumed to be related to the human body. In the event that the value exceeds the preset human body detection threshold value, the control unit 101 determines that there is a human body in the portions and outputs the human detection information that indicates the human body existing position.
In addition, for the portion that continues rapid temperature changes (heat source), the control unit 101 determines from the ambient temperature, as to whether the heat source is a human body or a device by the use of the human body detection threshold values preset within a range in which the human body temperature changes could occur, and outputs the human body detection information, etc. For example, even if a human suddenly begins exercising, the temperature changes by only about 10°C at maximum with errors included. In the event that the body temperature lowers, the control unit 101 computes errors using the air-conditioner cooling air settings and fans and takes the computed errors into account, and in the event that the change is the temperature change or temperature zone outside the range of human body detection threshold values, the control unit 101 determines that it is a heat source other than a human body, that is, a device. This improves the accuracy of the human body detection information.
In Step S8, in the event that regions judged to be a human body based on temperature changes are located close to each other (distance within the predetermined range), their regions are able to be considered as a same obj ect. Accordingly, their regions are grouped as the same object. This distance varies according to the circumstances taking the surrounding temperature information, etc. into account. For example, in the event that the ambient temperature is markedly lower than the human body radiation heat temperature, there is a possibility that the clothing, too, may be cooled, and keeping the distance to be regarded as the same object longer facilitates the precise extraction of human bodies. The control unit 101 is equipped with a mechanism to judge temperature changes caused by heat sources, etc. other than human bodies to be noises, based on the temperature variation and the size of groups at the time of grouping. The human body detection information is like binary images which express the temperature information with images (thermal images by thermal pixels) distinguished by using different colors such as thermo-viewers and which set a flag in the human existing area by computing a temperature difference between the sequential images. On the basis of the temperature information, the air conditioner 1 conducts air-conditioning control, centering the human body existing are, with a predetermined mode.
In the event that the change of thermal pixels concerning the temperature information is determined by the use of time difference (inter-frame difference) and human body detection is performed, multiple human body detection threshold values that correspond to multiple portions of a human body may be used. By doing this, for example, in the event that the temperature rise in the vicinity of feet is smaller than the temperature rise in the vicinity of the head, the heat level is divided into multiple steps in accordance with the relevant threshold values that correspond to the human body portions and the human body detection threshold values are established.
In the event that human body detection is simply performed by the time difference with one human body detection threshold value established, the feet may be overlooked when grouping is carried out by binary-coding. However, by the above-mentioned method, obj ects whose heat levels are adj acent from the vicinity of head to the vicinity of feet can be grouped as the same human body (same person), so that the human body can be clearly determined even up to the feet. In addition, in the event that the difference assumed to be the vicinity of feet is only detected, it may be regarded as noise and ignored or the accuracy of the detection may be improved by determining that the head portion is hidden and adding a process for determining whether the head portion would appear or not after plural cycles.
By increasing the number of human body detection threshold values in this way, high-temperature objects higher than the body temperature can be eliminated as noise (heat sources).
This technique can be applied not only to the human body but also other heat source. For example, in the vicinity of an automobile engine and in the vicinity of a tire, high temperature is acquired, but other portions are not so much high in temperature. Consequently, by using plural heat source detection threshold values that correspond to respective portions, it is also possible to accurately detect the contour of the whole automobile.
In Step S9 of FIG. 7, the control unit 101 finds a predetermined positional distance, for example, a center distance or gravity distance between each group of relevant groups such as group A grouped from the T1 and T2 temperature information, and group B grouped from T2 and T3 temperature information, etc., then regards the objects as the same object (for example, the same person) in the event that such distances are within a predetermined range. Needless to say, the control unit 101 may determine it by finding out whether or not the number of places overlapped for each group is greater than a predetermined value. In the event that the obj ects are regarded as the same person, the control unit 101 determines an amount of activity on the basis of the traveling history and traveling time of the person, estimates how much the body temperature of the relevant person rose on the basis of the amount of activity, and allows the fan 105 to perform air-conditioning control on the basis of the estimated temperature information. For example, in a case when the body temperature of the user rises and the user feels extremely hot just after carrying out furious activity, if the clothing is thick and the body temperature does not appear on the clothing surface, keeping low temperature, it was unable to cope with the case by conventional methods. However, by considering the amount of activity of the user as is the case of the present embodiment, it is possible to implement effective air-conditioning control that meets the temperature rise of the user. In addition, it is also possible to store a table that has behavioral patterns corresponding to favorite temperatures is stored in storage means (not illustrated) for each user in advance, and by collating the traveling history with the behavioral patterns stored, the user is identified, and the favorable temperature of individual user is acquired, and performing air-conditioning control on the basis of this temperature, the comfortable environment is able to be provided.
Furthermore, in the event that each group is configured by a quadrangle set upright, the distance between center position of the base of the quadrangles may be used. Now, to show one example of air-conditioning control, when the control unit 101 sets flags in the human body existing areas and performs the preset air-conditioning control, the control unit drives the louver 108 and directs the louver to the quadrangle base which is assumed to be the vicinity of the feet in the case of warming, and drives the louver 108 and directs the louver to the center of gravity of the quadrangle in the case of cooling. For the person who does not want to be subject to wind, the control unit 101 can conduct comfortable controls in accordance with the settings, such as performing air-conditioning with the air-conditioning air stream controlled, etc.
The human body detection threshold value for detecting the human body may be freely changed over in accordance with regions (Okinawa where it is warm even in the winter, Hokkaido where it is cool even in the summer, etc.) or to user's favorites. It is favorable that plural human body detection threshold values are stored in storage means (not illustrated) in advance. By change-over operation from the operation panel or remote controller by the user, the control unit 101 selects the corresponding human body detection threshold value from the storage means and operates the air-conditioner in accordance with the human detection threshold value thereafter. It is also possible to control the human detection sensitivity. For example, in the event that the ambient temperature is close to the human surface temperature, the human detection threshold value is set to be low to make the human body detection in the vicinity of the human body surface temperature (human body radiation heat temperature) more sensitive or by the use of the thermistor 21 of the outdoor unit 20 and the thermistor 12 of the indoor unit 10, the surface temperature of clothing of the user who returns home from a place where the user has gone is computed and the threshold value in the vicinity of the temperature can be lowered. In addition, considering variations in radiation heat by air-conditioning of the air-conditioner itself can reduce false detection.
The control unit 101 can vary the table of threshold values used for detection of heat sources, etc. in accordance with areas. For example, when the user operates to change a temperature setting from the operation panel or remote controller, the control unit 101 receives this setting through input means (not illustrated). The control unit 101 learns the human radiation heat and ambient temperature at the time when it receives the setting, finds the relational expression between the human radiation heat and the ambient temperature, and air-conditions so as to meet the relational expression. Because it means that there is a request for changing temperature by the user when the user changes the setting, the control unit 101 can achieve air-conditioning in accordance with users by learning how the temperature was set at the corresponding temperature of the human body radiation heat of the user. Furthermore, even when plural users utilize the same air-conditioner and temperature settings vary under the same condition, the temperature settings are averaged so that air-conditioningwhich satisfies a certain level of temperature requests of all users can be achieved. In the event that temperature raising setting and temperature lowering setting were learned in the past under the same condition, for example, at 28°C in the summertime and at 33°C for human body radiation heat, if the temperature information of temperature lowering setting is greater, it is considered that there is a strong temperature lowering request and the air-conditioning temperature is lowered. Taking such a case, in which the user may not want to be subject to air-conditioned air stream, into account, settings to direct the flap upwards and deceleration of the fan speed, etc. are carried out.
The human body detection threshold value and absence determination threshold value are changed on the basis of the average temperature of the temperatures detected by the thermopile 11 of the indoor unit 10 or the temperature detected by the thermistor 12. In addition, the control unit 101 determines in which part of the room the air-conditioned air stream flows at the time of warming, applies the value set in advance at the time of initialization, and corrects the temperature which is susceptible to heat generation or air-conditioned air stream of the air conditioner. The control unit 101 decides the human body detection threshold value and absence determination threshold, taking the temperature rise caused by them into account. At the time of warming, the control unit 101 gradually learns the temperature rising curve, computes the difference from the radiation heat at the time when the fan 105 is stopped, and modifies the human body detection threshold value and the absence determination threshold value to the values that meet the user room.
In Step S10 to S14 of FIG. 7, when a human body is detected, the control unit 101 adds a preset value to the humanbody existence value for determining whether or not a human exists, based on the human body detection information.
In the event that no human body is detected, the control unit 101 subtracts the preset value only in the range where the human body existence value exists. The control unit 101 subtracts the preset value from the human body existing value every time the temperature information is imported or each preset time, and when the human body existing value becomes less than the absence determining threshold value, the control unit 101 carries out absence determination only for the place where the motion is last detected.
The control unit 101 carries out absence determination to determine whether or not a human body exists, by the use of temperature change from grouped temperature information at the time when the human body is detected, as well as the temperature of the portion. According to this, it is possible to determine whether the person stops and does not move or the heat source is erroneously detected only at the place where the temperature is detected, and therefore, the absence determination can be reliably carried out. The control unit 101 resets the flag of the human body existing area with the absence determination and stops air-conditioning control for the portion or carries out energy-saving operation when the flag is reset. Consequently, it is possible to eliminate wasteful air-conditioning and achieve energy saving and increased air-conditioning efficiency.
Because the human detection is only based on the sequential temperatures on the time axis, the control unit 101 does not perform human body detection unless there is any temperature difference (temperature change). In addition, because household electrical appliances, etc. gradually increase temperature, even when any heat source close to the human body temperature exists, the control unit 101 does not make false detection as with the conventional technologies. In addition, even when the heat-generating devices rapidly increase temperature, the control unit 101 can cancel erroneous detection by the absence determination.
In the event that temperature detection means of a single element is used and made to scan to detect temperatures, the time lag is generated before the temperature information is acquired. Therefore, in the case of the plasma display panel TV, etc., the temperature rising value increases and there is a fear of erroneously detecting them as a human body. In addition, since the constant temperature in the vicinity of the human body radiation heat temperature is maintained at the time of the absence determination, it is difficult to make judgment. However, if the human body detection information can be refreshed (cancelled) at a set timing, for example, after a specified time, the control unit 101 does not continue erroneous recognition.
The human body existence value is expressed by f(n) and is the value obtained by adding the product of multiplying the human body existence value f(n-1) computed last time by the human body existence coefficient α and the product of multiplying the human body detection function F(n) generated at the time when the human body is detected by the human body detection coefficient β. The formula is given by: $f (n) = f (n - 1) \times α + F (n) \times β$

The value greatly rises when the human body is found, and it gradually lowers when the human body is not found. The human body existence coefficient α can be optionally changed by the user and it is possible to change the human body detection sensitivity, too. It is also possible to change or rewrite the method of computing the existence value in accordance with the types of air-conditioners, and servicing personnel and users can rewrite it via the network.
In the event that no human body is existent in the absence determination using the absence determining threshold values, the control unit 101 performs specified controls such as energy-saving operation, etc. in the range where no human body is existent. Note that the air conditioner 1 performs absence determination only at the place where the human body is detected.
Because in the conventional method, it is determined simply by the temperature difference and the temperature close to the human body temperature, objects having the temperature close to the human body temperature are erroneously detected, but in the present invention, the absence determination is added so that erroneous detection can be avoided.
In conventional inventions, once a heat source having the temperature close to the human body temperature is erroneously detected, there is no mechanism to carry out re-determination and the erroneous detection is continued. However, in the present embodiment, by carrying out absence determination and obtaining the difference from the temperature at the time when the human body is detected, it is determined that the human body is absent when the temperature change increases after a predetermined time. Consequently, because it is possible to reliably detect absence by avoiding the time of sudden temperature change, etc. caused by heat-generating devices, false detection does not continue and accurate human body detection can be performed. For the threshold value table for human body detection and the threshold value table for absence determination, different tables are, in general, used. By doing so, the threshold value in the vicinity of the human body temperature can be made smaller and even with slight changes, the human body can be detected. In addition, the user can set the human body detection sensitivity in several steps by settings. Furthermore, using separate tables for the threshold value table used for human body detection and the threshold value table used for absence determination produces an effect that absence is not determined by the change of wearing a jacket, etc. In addition, in the conventional method, absence is determined when the human body has not detected for a certain time at the place where the human body detection is carried out and appropriate air-conditioning is unable to be performed for a person who is standing still. In this embodiment, however, by carrying out absence determining processing, air-conditioning can be properly performed for a person who stands still.
Furthermore, the control unit 101 can refresh (cancel) the information on the human body detection in a predetermined timing. By this, should any false detection be made, correct detection can be performed at the time of next refreshing so that continuation of false detection can be avoided. It is possible to refresh the information as needed from a remote controller. In addition, when the human body is unable to be detected, for example, when the ambient temperature is close to the human body radiation heat temperature and it is difficult to detect the human body, the control unit 101 may drive a fan 105 to perform air-conditioning control and perform air-conditioning control temporarily to the detectable temperature or may learn the past human body detection information and temperature information to store the weighting in memory, so that the control unit 101 performs comprehensive control based on the weighting distribution. By this, wasteful air-conditioning can be suppresseduntil the temperature changes to the human body detectable temperature, and lowering of energy saving effects can be suppressed during the time until the human body is detected. By the behavioral patterns registered in advance on the basis of the studied behavioral patterns, individual identification is performed as to which person and optimum air-conditioning may be performed for each individual. Once the behavioral patterns are studied, even if clothing is thick and temperature change is not markedly shown, the human body temperature increase is estimated from the amount of activity, and comfortable air-conditioning control can be performed.
The control unit 101 also may compute an amount of activities of the human body from a variation of the positions
in which the human body was detected, and estimate the temperature rise of the human body based on the amount of activities, so as to conduct air-conditioning control based on the estimated temperature rise.
Foe example, with respect to the human body detected again in the vicinity of the area where a human body was detected before, the control unit 101 judges it as a human body which stays in the vicinity and has a small amount of activity. On the other hand, a human body detected in an area other than that in which the human body was previously detected is judged to provide a large amount of activity.
In the event of a high frame rate (a short cycle), a person within a certain range can be determined as the same person, and the traveling region can be computed, so that the amount of activity can be easily determined.
However, in the case of a slow frame rate or in the case of a method to obtain heat images by scanning, this technique is effective. The present technique adopts a method to add a value at the position where the human body was continuously detected, and to subtract the value from the place where any change is made. The person who first appears provides a large amount of activity because the person enters from the outside, and the person who stays in the same place provides a small amount of activity. Even in the case that the person goes out of the room temporarily and returns to the room, if the person nearly stays in the place where the human body was detected, the amount of activity is small.

Second Embodiment

In the first embodiment, in the event that a human body is detected in a certain area, if the heat source does not move at the time when a thermal image is compared to a next thermal image, absence determination must be performed and the presence and the absence of a person must be determined. In a second embodiment, a more simplified way will be described.
For example, when a human body is detected, a thermal pixel at the time before the human body is detected is overwritten as a background image to the thermal pixel portion of the human body detection range of the thermal image that expresses the temperature distribution. In such event, the background temperature thermal pixel of a range other than the human body detecting range is overwritten as it is. Because this produces a difference between the background image and the heat source image even in a case when the person does not move at the time when the time advances to the next cycle (frame), absence or presence of a person can be easily determined. By this, it is possible to simply determine how long the person has been staying in the area without carrying out the absence determination of the first embodiment.
In the event that the background temperature of the range other than the area where the human body is detected is updated, the human body detection threshold value is decided from the average ambient temperature by the previous thermal pixels when the human body moves newly, so that the accuracy of the detection results is thereby increased. Furthermore, since the average ambient temperature is computed in the human body detection area by the use of the ambient temperature and the last background temperature at the human body detection position, the optimum human body detection threshold value can be applied and the detection errors can be reduced.
When the human body is detected in the event that a person stays in the same position and the surrounding background temperature is varied, there is a possibility of making a mistake in determining absence in such a case that the ambient temperatur changes before the person moves, and the background image before the human body detection becomes identical to the present background temperature, because thermal pixels before the human body is detection is overwritten as the background image to the thermal pixel portion of the human body detection range.
To cope with this, in the event that the average value of the ambient temperature increases while a person stays, i is desirable to perform corrections of thermal pixels of the portion where the person stays, in accordance with the surrounding environmental temperature. For example, in the event that the background temperature at the time before a person moves in is 10° and a person of 32°C moves in, and when the ambient temperature increases to 20°C thereafter and the person moves the difference between 20°C and 10°C may be detected as 10°C Therefore, in such event, based on the thermal pixels at the human body detection area or around the human body, the temperature corrections are added to the human body staying background temperature thermal pixel portion. By this, even if a person moves, it is not erroneously detected that the person stays and the presence and absence can be determined correctly
In each of the above embodiments, the air-conditioner carries out air-conditioning control as described above. In the event that the air-conditioner 1 separately outputs the wind in, for example, 6 patterns (6 areas) only, it is possible to carry out air-conditioning by setting a flag that indicates a human body existing area for each area, and the above-mentioned air-conditioning control can be applied to any type of air conditioner 1.
In the air-conditioner 1 of each of the above embodiments, each kind of the above information can be utilized through networks in addition to being utilized for automatic control of the air conditioner 1. In such event, for example, in the case of a long distance, it is configured to separately provide the indoor unit 10 with radio communication means for making communications with cellular phones and to make communication between the cellular phones and the control unit 101 of the indoor unit 10 via the radio communication means. In addition, in the case of a short distance, it is configured to separately provide the indoor unit 10 with radio communication means for receiving signals from a remote controller and to make communication between the remote controller and the control unit 101 of this indoor unit 10 via the radio communication means. By the foregoing configuration, for example, because the human body can be detected at the time when the user is absent, the airconditioner can be used for crime-prevention or for monitoring the state of animal indoors. Furthermore, in the case of frequent remote control operation, it is possible to change the threshold values and settings preset in the memory of the air conditioner 1, or an optimum value can be chosen from the database through networks. In addition, in linkage with other equipment, for example, by setting the air-conditioning temperature to be slightly lower by judging the condition after taking a bath from the information from the water heater, still more energy saving can be achieved. Furthermore, based on the information from other equipment such as absence and presence information, etc. by room door open/close sensor or radio tags, still more accurate human body detection and comfortable control can be carried out.
Note that the temperature detector which detects the heat source of a human body, etc. discussed in the first and second embodiments shall not always be restricted to thermopiles used herein but other temperature detection sensors which have similar functions may be used.
Furthermore, it is also possible to take out only the temperature detector from the air-conditioner 1 and operate it as a single sensor unit, which can be incorporated in or externally attached to other household electrical appliances and facilities.

Claims

An air conditioner comprising:
a temperature detection means that detects temperature while scanning a temperature detection covering range;

a temperature detection means drive circuit that drives the temperature detection means; and

a control unit that controls the temperature detection means drive circuit,
wherein the control unit directs the temperature detection means drive circuit to allow the temperature detection means to scan in such a manner as to overlap a partial region of a temperature detection range of the temperature detection means, and to detect temperature with the overlapped partial region.
An air conditioner comprising:
plural temperature detection means installed corresponding to plural regions formed by dividing the temperature detection covering range; and

a control unit that controls the temperature detection means,
wherein the control unit allows the plural temperature detection means to detect temperatures in such a manner as to overlap a partial region of a temperature detection range of the temperature detection means.
The air conditioner according to claim 1 or 2, wherein the control unit comprises:
a comparison unit that computes temperature differences based on sequential temperature information obtained from the temperature detection means and compares the temperature differences with a predetermined threshold value according to a kind of heat sources; and

a heat source detection unit that determines that a heat source corresponding to the threshold value has been detected and computes where the heat source exists in the event that the temperature difference obtained by the comparison unit exceeds the threshold value.
The air conditioner according to claim 3, wherein the heat source detection unit adds a preset value for the computed heat source detected position, subtracts the preset value for a position in which no heat source is detected, and in the event that a human existence value to and from which the preset value was added or subtracted becomes equal to or less than a absence determining threshold value, compares temperature changes from the time when the heat source was detected only at a place where a temperature change was detected last time, and determines whether or not there is any heat source.
The air conditioner according to claim 3 or 4, wherein the control unit regards heat sources as a same object and group them in the event that a distance between predetermined portions of regions where presence of a heat source is determined is in a predetermined range.
The air conditioner according to claim 5, wherein the control unit varies the distance which is a condition to regard heat sources as the same object in accordance with a ambient temperature conditions when a grouping is performed.
The air conditioner according to claim 5 or 6, wherein the control unit estimates an amount of activity of the same object on the basis of a traveling history and/or traveling time of the same object, presumes a temperature rise of the same object on the basis of the amount of activity, and carries out air-conditioning control on the basis of the presumed temperature rise.
The air conditioner according to any of claims 4 to 7, further comprising:
storage means that stores memory tables in which relevant behavioral patterns and/or temperature patterns are brought to correspond to optimum temperatures in accordance with kind of prescheduled heat sources, wherein the control unit identifies a behavioral pattern and/or a temperature pattern on the basis of a traveling history and traveling time of the same object, and from these the behavioral pattern and temperature patterns and the behavioral patterns and/or temperature patterns stored in memory in the storage means, identifies an applicable heat source, acquires the optimum temperature of the relevant heat source, and based on the temperature, carries out air-conditioning control.
The air conditioner according to any of claims 5 to 8, further comprising:
a wind direction adjusting plate that adjusts a direction of the air blowing out from an indoor unit,
wherein the control unit changes the direction of the wind direction adjusting plate in accordance with a shape of the grouped groups.
The air conditioner according to any of claims 4 to 9, wherein the threshold values used for detection of heat sources are changed in accordance with a mean temperature obtained by the temperature detection means or room temperature of the temperature detection covering range.
The air conditioner according to any of claims 4 to 10,
wherein differences are made between threshold values used for the heat source detection and threshold values used for the absence determination.
The air conditioner according to any of claims 3 to 11, wherein the control unit once conducts air-conditioning control to lower temperature with a focus on a place where the heat source is to be detected or a place with high probability of human body presence which the control unit has learned before, in the event that an ambient temperature of the place where the heat source is to be detected is in the vicinity of human body radiation heat temperature, and thereafter, resumes detection of heat sources.
The air conditioner according to any of claims 1 to 12,
wherein the control unit can vary a overlapping amount of a partial region of the temperature detection range of the temperature detection means.
The air conditioner according to any of claims 3 to 13, wherein the control unit cancels results of the heat source detection and absence determination in a preset timing.
The air conditioner according to any of claims 1 to 14, wherein the control unit comprises compensation means that compensates for temperature caused by heat generated by the air conditioner itself or air conditioning air stream.
The air conditioner according to any of claims 3 to 15, wherein tables containing the threshold values can be changed over by regional information, date information or outside instructions.
The air conditioner according to claim 4, wherein the control unit determines the absence of a human body on the basis of the difference between a detection temperature of the temperature detection means at the time when the human body is detected and a current detection temperature of the temperature detection means.
The air conditioner according to any of claims 3 to 17, wherein the control unit expresses the detection temperature of the temperature detection means as thermal images, and generates the thermal images that express the temperature of a position where a human body was detected, using either one of an ambient temperature of a position where the human body was detected or a background temperature of the human body detected position at the time before the human body was detected.
The air conditioner according to claim 18, wherein the control unit corrects the background temperature of the human body detected position on the basis of the relevant region or the ambient temperature while a human body stays at the same position.
The air conditioner according to any of claims 3 to 19, wherein a plurality of human body detection threshold values are set corresponding to a plurality of portions of a human body, and based on the plurality of threshold values, the human body is detected.
The air conditioner according to claim 5 or 6, wherein the control unit computes an amount of activities of the human body from a variation of positions in which the human body is detected, and temperature rise of the human body is presumed based on the amount of activities, and air conditioning control is conducted based on the presumed temperature rise.
The air conditioner according to any of claims 1 to 21, wherein the air-conditioner is configured to be able to detach the temperature detection means from the indoor unit and allow it to be operated alone.