JP2017146157A - Range finder for bathroom and range method for bathroom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bathroom monitoring device and a bathroom monitoring method that can be put into practice at low cost.SOLUTION: A bathroom monitoring device comprises: a range unit that obtains first distance information indicating distance to each place in a bathroom by emitting a range wave and receiving a reflection wave in the bathroom where there is a person; a storage unit that stores bathroom positional information indicating the position of a first prescribed place in the bathroom; and a processing unit that obtains person positional information indicating the position of a prescribed region of the person in the bathroom on the basis of the first distance information, compares the bathroom positional information with the person positional information, and performs control to output a warning from an alarm unit on the basis of the comparison result.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bathroom distance measuring device and a bathroom distance measuring method using a distance measuring unit that emits a distance measuring wave and receives a reflected wave thereof to acquire distance information to a distance measuring object.

  As the bathroom distance measuring apparatus as described above, for example, it is used in a bathroom monitoring apparatus described in Patent Document 1.

  The bathroom monitoring apparatus of Patent Literature 1 includes a three-dimensional sensor that acquires three-dimensional information in a target area, and a height change detection unit that detects a change in height in the target area based on the acquired three-dimensional information. A position detecting means for detecting the position of the object based on the detected height change; a motion detecting means for detecting the movement of the object based on the detected height change; Risk determination means for determining whether or not the object is in a dangerous state based on the position and movement of the object, and the risk determination means determines whether or not the object is in a dangerous state. Based on the criteria set for each position.

Japanese Patent No. 3979238

  Patent Document 1 describes that a TOF (Time-Of-Flight) type distance sensor using light may be used. However, the light emitted from the distance sensor may only be specularly reflected by a mirror in the bathroom. In this case, since the distance sensor cannot accurately measure the distance, there is a problem in that bathroom monitoring is affected.

  Therefore, an object of the present invention is to provide a bathroom distance measuring device and a bathroom distance measuring method that can perform bathroom monitoring more accurately.

  In order to achieve the above object, the first aspect of the present invention is to emit a ranging wave in a bathroom and receive a reflected wave in a bathroom by a TOF (Time-of-Flight) method, so that a plurality of locations in the bathroom are provided. A distance measuring unit that acquires distance information including a distance to and a central processing unit that invalidates a distance greater than or equal to a predetermined value among the distances included in the distance information. .

  In addition, the second aspect of the present invention is a distance including distances to each location in the bathroom by emitting a ranging wave in the bathroom and receiving a reflected wave by the TOF (Time-of-Flight) method. The method is directed to a bathroom ranging method comprising: obtaining information; and invalidating a distance greater than or equal to a predetermined value among the distances included in the distance information.

  According to each aspect described above, it is possible to provide a bathroom distance measuring device and a bathroom distance measuring method that can perform bathroom monitoring more accurately.

It is a figure which shows the structure of the bathroom monitoring apparatus which concerns on each embodiment. It is a figure which shows the ranging wave and reflected wave of the ranging part of FIG. It is a figure which shows the detailed structure of the control part of FIG. It is a flowchart of the initial setting process which the control part of FIG. 1 performs. It is a flowchart of the warning process which the control part of FIG. 1 performs. It is a schematic diagram which shows an example of 1st monitoring area | region information. It is a schematic diagram when the bathroom when a person is present is viewed from above. It is a schematic diagram which shows the other example of 1st monitoring area | region information. It is a schematic diagram which shows the float which the bathroom monitoring apparatus of 1st embodiment can comprise. It is a flowchart of the warning process which concerns on a 1st modification. It is a flowchart which shows the first half part of the warning process which concerns on a 2nd modification. It is a flowchart which shows the second half part of the warning process which concerns on a 2nd modification. It is a flowchart of the initial setting process which concerns on 2nd embodiment. It is a flowchart of the warning process which concerns on 2nd embodiment. It is a schematic diagram which shows an example of 2nd monitoring area | region information. It is a schematic diagram which shows the invalid distance by specular reflection.

<< 1. First embodiment >>
Hereinafter, the bathroom monitoring apparatus A according to the first embodiment will be described in detail with reference to the drawings.

<< 1-1. Configuration of bathroom monitoring device A >>
In FIG. 1, the bathroom monitoring device A includes a distance measuring unit 1, a control unit 2, and an alarm unit 3.

  The distance measuring unit 1 is, for example, a TOF (Time-Of-Flight) type three-dimensional distance image camera, and is installed on the ceiling of a bathroom so that its optical axis is directed vertically downward. The distance measuring unit 1 includes a light source unit 11, a drive circuit 12, a light receiving unit 13, and a signal processing circuit 14 in order to acquire distance image information Idst described later.

  The light source unit 11 includes at least one light source element such as an infrared LED. When the drive signal Sin is input from the drive circuit 12, the light source unit 11 is a range-finding wave L <b> 1 that spreads in various directions within its angle of view. Radiates in.

  The radiated ranging wave L1 is reflected on the surface of the bathroom interior (for example, a bathtub, a floor, etc.) if there is no person in the bathroom. On the other hand, if there is a person in the bathroom, the distance measuring wave L1 is reflected not only on the interior surface but also on the surface of the human body. Here, in the description of the present embodiment, reflection is a concept including specular reflection and diffuse reflection. The reflected wave L2 on the interior surface or the human body surface is incident on the light receiving unit 13.

  The light receiving unit 13 typically includes a plurality of light receiving elements (for example, CCDs) arranged in a two-dimensional array. A light component reflected by the interior or the human body in the reflected wave L2 is incident on each light receiving element. Each light receiving element performs photoelectric conversion, generates a signal Sout indicating the intensity of the incident light component to the element, and outputs the signal Sout to the signal processing circuit 14.

  The signal processing circuit 14 receives the drive signal Sin of the drive circuit 12 and the output signal Sout of each light receiving element. The signal processing circuit 14 obtains a phase difference φ between the two input signals Sin and Sout for each of the plurality of light receiving elements, and obtains a spatial distance from the light source unit 11 to each reflection point based on the obtained phase difference φ. . Thereafter, the signal processing circuit 14 outputs a collection of spatial distances obtained for each light receiving element as distance image information Idst to the control unit 2 at a predetermined frame rate (for example, 30 frames / second). In other words, the distance image information Idst has a spatial distance from the distance measuring unit 1 to the interior surface or the human body surface as a pixel value.

  Here, FIG. 2 shows the distance measuring unit 1 installed on the ceiling of the bathroom 4, a person 42 in the bathtub 41, and a wall 43 around the bathtub 41. The ranging wave L1 radiated from the ranging unit 1 is reflected by the bathtub 41, the person 42, the wall 43, or the like, and received by the ranging unit 1 as a reflected wave L2. Here, in FIG. 2, the example of the reflection part on the wall 43 is a, the example of the reflection part on the upper end of the bathtub 41 is b, and the example of the reflection part on the bottom of the bathtub 41 or the floor of the washing place is c. Thus, examples of the reflection locations at the top 44 of the person 42 and other portions 45 are indicated by d and e. In this case, the distance image information Idst is a collection of spatial distances to the reflection points a to e. Note that reference numerals L1 and L2 are shown only near one light component (that is, an arrow) so that FIG. 2 is not complicated.

  In FIG. 3, the control unit 2 includes a communication unit 21, a CPU 22 that is an example of a processing unit, a nonvolatile memory 23, and a main memory 24.

  The communication unit 21 is a communication interface between the control unit 2, the distance measuring unit 1, and the alarm unit 3. The CPU 22 executes the program P stored in advance in the nonvolatile memory 23 using the main memory 24 as a work area.

  The alarm unit 3 is, for example, a speaker and can be arranged at various locations. For example, if the bathroom monitoring device A is installed in a house, the alarm unit 3 is installed in, for example, a bathroom or outside the bathroom (for example, a living room). If the installation location is a nursing facility or the like, the alarm unit 3 may be a PC speaker connected to the control unit 2 via a wired network in a separate room from the bathroom, or a wireless communication terminal connected wirelessly It may be a speaker of a wireless communication terminal (for example, a smartphone) owned by a care worker. In addition, the alarm unit 3 may be installed in a bathroom. The alarm unit 3 as described above outputs an alarm sound for a serious situation (for example, drowning or falling) in a bathroom according to various alarm sound data Isnd generated by the control unit 2.

<< 1-2. Operation of bathroom monitoring system >>
Next, the operation of the control unit 2 will be described in detail with reference to FIG. 4 and FIG.

  The CPU 22 first performs the initial setting process of FIG. 4 when there is no person in the bathroom. In step S <b> 01, the CPU 22 radiates the ranging wave L <b> 1 from the light source unit 11. The distance measuring wave L1 is reflected at various locations on the interior surface of the bathroom and is incident on the light receiving unit 13 as a reflected wave L2.

  In step S02, the signal processing circuit 14 of the distance measuring unit 1 generates the above-described distance image information Idst for at least one frame based on the output signal Sout of the light receiving unit 13, and the control unit 2 (more specifically, the main memory). 24). At the time of initial setting, the distance image information Idst is a collection of only the distances to the reflection points on the interior surface in the bathroom. In this description, this distance image information Idst is referred to as second distance image information Idst2.

  In step S03, the CPU 22 stores the second distance image information Idst2 obtained from the distance measuring unit 1 in the nonvolatile memory 23 (see FIG. 3) which is an example of a storage unit.

  In step S04, the CPU 22 converts the spatial distance for each pixel position to, for example, a vertical position with the light emitting point position of the distance measuring unit 1 as the origin by performing perspective projection conversion on the second distance image information Idst2, and the like. By the point extraction process, a pixel group having a substantially rectangular shape and a rectangular shape is searched for. In the case of a bathroom, as such a pixel group, a washing place and an outline of the upper end of the bathtub may be recognized. The CPU 22 defines a pixel group closer to the distance measuring unit 1 (that is, the ceiling) as an outline of the upper end of the bathtub 41 (indicated by b in FIG. 6), and a region within the outline (thick in FIG. 6). First monitoring area information t1 indicating (indicated by a broken line) is stored in the nonvolatile memory 23 (see FIG. 3).

  In step S05, the CPU 22 defines the bathtub upper end as a first example of a predetermined location in the bathroom, and stores the vertical position in the nonvolatile memory 23 as upper end position information I1 which is an example of bathroom position information (FIG. 3).

  This completes the initial setting process of FIG.

  The CPU 22 performs the warning process of FIG. 5 after the initial setting process. In step S11, the CPU 22 radiates the ranging wave L1 from the ranging unit 1 as described above. The distance measuring wave L1 is reflected at each location on the interior surface of the bathroom or each location of a person, and enters the light receiving unit 13 as a reflected wave L2.

  In step S <b> 12, the signal processing circuit 14 generates the above-described distance image information Idst based on the output signal Sout of the light receiving unit 13 and transfers it to the control unit 2 in units of frames. At this time, if there is a person in the bathroom, the distance image information Idst is a collection of spatial distances not only to the interior surface in the bathroom but also to each reflection point on the human body surface, as shown in FIG. In FIG. 7, the reflection location at the upper end of the bathtub 41 is indicated by b, the reflection location at the portion 45 excluding the parietal portion 44 in the person 42 is indicated by c, and the reflection location at the top 44 is indicated by d Show. In addition, illustration of other reflection locations is omitted for convenience. In the present description, the distance image information Idst obtained in step S12 is referred to as first distance image information Idst1. The first distance image information Idst1 is sequentially stored for each frame in the main memory 24 via the communication unit 21 under the control of the CPU 22.

  In step S13, the CPU 22 confirms whether or not there is a person in the bathtub. More specifically, the difference between the pixel values belonging to the first monitoring region t1 is calculated in each of the distance image information Idst1 and Idst2. If this difference is greater than or equal to a predetermined threshold, it is determined that there is a person in the bathtub.

  If it is determined in step S13 that there is a person in the bathtub, in step S14, the CPU 22 performs a perspective projection conversion and a feature point extraction process on the latest frame of the first distance image information Idst1 to obtain a predetermined part of the person. A human head top 44 (indicated by “d” in FIG. 7) is specified as a typical example, and the vertical position thereof is held as head position information I2 which is an example of human position information.

  In next step S <b> 15, the CPU 22 first reads the upper end position information I <b> 1 from the nonvolatile memory 23. Thereafter, the CPU 22 calculates the bathroom position based on the comparison result between the vertical position of the top obtained in step S14 (that is, the latest head position information I2) and the vertical position of the upper end of the bathtub (that is, the upper position information I1). To determine whether the person is drowning. More specifically, the CPU 22 subtracts the vertical position of the upper end of the bathtub from the vertical position of the top 44, and determines whether or not the difference obtained thereby is equal to or less than a predetermined threshold value. Make a flood judgment. Here, since this bathroom monitoring apparatus A aims at making a flood determination, the threshold is selected to be about 20 cm.

  If it is determined in step S15 that the water is not flooded, the CPU 22 returns to step S11 in order to update the first distance image information Idst1 and the head position information I2. On the other hand, if it is determined that the water is flooded, the CPU 22 sets the volume of the warning sound to the initial standard volume in step S16. Thereafter, in step S17, the CPU 22 generates first warning sound data Isnd1, which is one of various warning sound data Isnd and represents a warning of flooding with a sound of a set volume, and transmits the first warning sound data Isnd1 to the warning unit 3. The alarm unit 3 outputs a set volume alarm based on the received first alarm sound data Isnd1.

  Next, in step S18, when the first predetermined time has elapsed after issuing the warning in step S17, the CPU 22 updates the head position information I2 in step S19, and then makes a flood determination in step S110. In addition, the process of step S19, S110 is the same as that of step S14, S15. The first predetermined time is selected to be about 10 seconds.

  If it is determined in step S110 that the water is flooded, the CPU 22 regards the situation as more serious in step S111, sets the volume of the warning sound to be higher than the standard volume, and then performs step S17. By this processing, the warning unit 3 gives a warning by using different methods at intervals. In particular, since the warning volume gradually increases, the care staff can recognize the seriousness of the situation. On the other hand, if it is determined in step S110 that the water is not flooded, the person in the bathtub is deemed to have escaped from the flooded state, and the process returns to step S11. Thereafter, the same processing as described above is performed.

  By the way, if it is determined in step S13 that there is no person in the bathtub, the CPU 22 determines in step S112 whether or not a second predetermined time has elapsed. When the second predetermined time has elapsed in step S112, the CPU 22 considers that no person has entered the bathtub for some time in the future, and updates the second distance image information Idst2 in step S113. Since the process of step S113 is the same as the process of steps S01 to S03 of FIG. 4, a detailed description thereof will be omitted here. In step S113, at least the second distance image information Idst2 may be updated, but the first monitoring area information t1 and the upper end position information I1 may be updated at the same time.

  After determining that the second predetermined time has not elapsed in step S112 after the process in step S113, the CPU 22 performs step S11 again. Since the subsequent processing is as described above, it will not be described in detail here.

<< 1-3. Effects of the first embodiment >>
As described above, according to the present embodiment, an alarm is generated by an extremely simple process of comparing the position d of the head portion 44 of the person in the bathroom 4 and the upper end position b of the bathtub 41 (see FIGS. 2 and 7). Since it can do, it becomes possible to provide the bathroom monitoring apparatus A realizable at low cost. Moreover, the camera which produces | generates the normal two-dimensional image which consists of the pixel value which shows a color and a light and shade is unnecessary for the bathroom monitoring apparatus A. This also enables the bathroom monitoring apparatus A to be realized at low cost and eliminates the user's psychological burden of installing a camera in the bathroom.

  In the bathroom monitoring apparatus A, the CPU 22 automatically acquires the upper end position information I1 indicating the vertical position of a predetermined location in the bathroom 4 and stores it in the nonvolatile memory 23 by the initial setting process of FIG. In other words, when installing the bathroom monitoring device A in the bathroom, the installer need not bother to set the upper end position information I1 in the bathroom monitoring device A. Thus, according to this bathroom monitoring apparatus A, it becomes possible to reduce the work man-hour of an installer.

  Further, in the bathroom monitoring apparatus A, the CPU 22 performs steps S14 and after in FIG. 5 only when it is determined in step S13 in FIG. 5 that a person is in the bathroom. Therefore, it is not necessary to unnecessarily perform feature point extraction with a large processing load.

  Moreover, when the light source part 11 radiates | emits the infrared ranging wave L1, the ranging wave L1 is not reflected by the water surface in a bathtub. Therefore, in the bathroom monitoring device A, it is possible to provide the bathroom monitoring device A that can be realized at low cost as described above by recognizing the upper end position of the bathtub 41 and using it for flooding determination. .

  Further, by incorporating steps S18 to S111 into the warning process of FIG. 5, in the bathroom monitoring device A, the CPU 22 controls to issue a warning a plurality of times at different volumes over time. Thereby, it becomes possible to give a warning according to the seriousness of the situation.

<< 1-4. Appendix >>
In the above description, the distance measuring unit 1 has been described as a three-dimensional distance image camera. However, the present invention is not limited to this, and the distance measuring unit 1 may be a so-called reception scanless type three-dimensional image radar. In this case, the light source unit 11 further includes an infrared LED, a MEMS mirror, and the like. Laser light with a beam diameter from the infrared LED narrowed relatively thin is incident on the MEMS mirror. The MEMS mirror deflects incident laser light. The light deflected by the MEMS mirror is scanned in the bathroom as another example of various ranging waves. Even in the case of the reception scanless type, the configuration of the light receiving unit 13 is substantially the same as described above.

  In the above description, the various ranging waves are assumed to be light. However, the present invention is not limited to this, and the ranging wave may be a radio wave.

  In the above description, the first monitoring region t <b> 1 is a region surrounded by the upper end outline of the bathtub 41. However, the present invention is not limited to this, and as shown in FIG. 8, the first monitoring region t1 may be a region offset inward by a predetermined amount from the outline. Thereby, in step S13 of FIG. 5, it is possible to reduce the possibility that a shower installed on the wall 43 and whose vertical position is frequently changed is erroneously recognized as a human body.

  In the above description, the volume of the warning sound is increased in step S111 in FIG. However, the present invention is not limited to this, and the frequency of the warning sound may be increased.

  In the above description, the upper end position information I1 indicates the vertical position of the upper end of the bathtub 41. However, the present invention is not limited to this, and as shown in FIG. 9, when the float 5 having a specific pattern formed on the surface using a retroreflective material is floated on the bathtub 41, the CPU 22 performs the first process in the warning process. It is also possible to determine flooding by obtaining the vertical position of the float 5 as the upper end position information I1 from the one-distance image information Idst1. As a result, more accurate flooding determination can be made, and step S05 in FIG. 4 can be omitted.

  In the above description, as a preferred mode, the CPU 22 automatically obtains the upper end position information I1 indicating the vertical position of a predetermined location in the bathroom 4 and stores it in the nonvolatile memory 23 by the initial setting process of FIG. It was. However, the present invention is not limited to this, and the installer may set the upper end position information I1 in the bathroom monitoring device A when the bathroom monitoring device A is installed in the bathroom.

  In the above description, as a preferred mode, the bathroom monitoring apparatus A uses both distance image information Idst1 and Idst2. However, the present invention is not limited to this, and when installing the bathroom monitoring apparatus A, if the installer stores the upper end position information I1 in the non-volatile memory 23 in advance, control is performed so that only the first distance image information Idst1 gives a warning. Is possible.

<< 1-5. First variation >>
Next, with reference to FIG. 10 etc., the bathroom monitoring apparatus B which concerns on the 1st modification of 1st embodiment is demonstrated. Since the bathroom monitoring device B is similar in configuration to the bathroom monitoring device A, FIGS. 1 and 3 are used in the following description. However, the bathroom monitoring apparatus B is different from the bathroom monitoring apparatus A in that the warning process illustrated in FIG. 10 is performed instead of the warning process illustrated in FIG.

  FIG. 10 is different from the warning process of FIG. 5 in that steps S21 to S23 are further provided between step S15 and step S16. Since there is no difference between the two flow diagrams other than that, in FIG. 10, the same step numbers are assigned to those corresponding to the steps in FIG.

  In step S21 of FIG. 10, the CPU 22 determines whether or not a third predetermined time has elapsed since the execution of step S15. The third predetermined time is a time shorter than the first predetermined time (for example, 5 seconds), and is a time when it can be considered that a person is voluntarily diving in the bathtub instead of flooding.

  If it is determined Yes in step S21, the CPU 22 performs steps S22 and S23 similar to steps S14 and S15. Thereby, the head position information I2 is updated, and the upper end position information I1 is compared with the updated head position information I2. If it is not determined to be flooded in this step S23, the CPU 22 considers that the person is voluntarily diving in the bathtub. In this case, the process returns to step S11. On the other hand, if it is determined that the water is flooded in step S23, the process proceeds to step S16.

<< 1-6. Effect of the first modification >>
When the bathroom monitoring device A determines flooding in step S15, it immediately gives a warning. Therefore, a warning is repeatedly issued from the bathroom monitoring device A to a person who voluntarily dive in the bathtub, but not for flooding, for a short time. Therefore, it is assumed that such a person feels annoying the warning by the bathroom monitoring device A.

  However, even if the bathroom monitoring device B determines that the water is once flooded in step S15, the bathroom monitoring device B does not give a warning unless it is determined that the water is again flooded after the third predetermined time. As a result, it is possible to reduce the frequency with which a person who voluntarily dives feel annoyance.

<< 1-7. Second modification >>
Next, with reference to FIG. 11A, FIG. 11B, etc., the bathroom monitoring apparatus C which concerns on the 2nd modification of 1st embodiment is demonstrated. Compared with the bathroom monitoring apparatus A, the bathroom monitoring apparatus C is different in that the control unit 2 performs a warning process including a combination of FIGS. 11A and 11B instead of the warning process of FIG. Other than that, there is no difference between the bathroom monitoring devices A and C. Therefore, FIG. 1 and FIG. 3 are used below.

  11A and 11B is different from the flowchart of FIG. 5 in that steps S31 to S33 are further performed, for example, between steps S14 and S15. Other than that, there is no difference between the two flow diagrams. Therefore, in FIG. 11, the steps corresponding to the steps shown in FIG.

  In step S31, the CPU 22 determines how much the human head portion 44 has been displaced in the vertical direction per unit time from the current head position information I2 and the previous head position information I2, that is, the human head portion 44. The moving speed v1 in the vertical direction is calculated.

  In step S32, the CPU 22 determines whether or not the obtained moving speed v1 is equal to or greater than a predetermined threshold value vth. Here, the threshold value vth is a value that can be considered that the person in the bathtub has fallen, and is obtained in advance by an experiment or the like.

  In this description, the CPU 22 is described as performing the fall determination based on the moving speed v1, but the present invention is not limited to this, and the fall determination may be performed based on the acceleration k1 of the human head 44.

  If it is determined in step S32 that the vehicle has fallen, in step S33, the CPU 22 generates second warning sound data Isnd2 which is one of various types of warning sound data Isnd and represents a fall warning with a sound of a set volume. Send to part 3. The alarm unit 3 outputs a set volume alarm based on the received second alarm sound data Isnd2.

  After step S33 or when it is not determined that the vehicle has fallen in step S32, the CPU 22 performs step S15.

<< 1-8. Effects of the second modification >>
As described above, according to this modification, it is possible to add the value of a warning when a person in the bathroom 4 falls by simply accumulating the upper end position information I1 and performing a simple calculation.

  In addition, since steps S31 to S33 are performed before step S15 or after it is determined No in step S110, bathroom monitoring device C is used immediately after a person enters the bathtub or when a person tries to leave the bathtub. For example, it is possible to issue an alarm in a situation where a fall is likely to occur.

≪2. Second embodiment >>
Next, with reference to FIG. 12 etc., the bathroom monitoring apparatus D which concerns on 2nd embodiment is explained in full detail. Compared with the bathroom monitoring apparatus A, the bathroom monitoring apparatus D is that the control unit 2 performs the initial setting process of FIG. 12 and the warning process of FIG. 13 instead of the initial setting process of FIG. 4 and the warning process of FIG. Is different. Other than that, there is no difference between the bathroom monitoring devices A and D. Therefore, FIG. 1 and FIG. 3 are used below.

<< 2-1. Operation of bathroom monitoring system >>
First, FIG. 12 differs from FIG. 4 in that steps S41 to S44 are included instead of steps S04 and S05. Other than that, there is no difference between the two flow diagrams. Therefore, in FIG. 12, the steps corresponding to the steps in FIG. 4 are given the same step numbers, and the descriptions thereof are omitted.

  In step S41, the CPU 22 performs an invalid process on the second distance image information Idst2 on the assumption that there is a mirror (that is, a specular reflector) at the washing place in the bathroom. Specifically, the CPU 22 invalidates a pixel value greater than or equal to a predetermined value among the pixel values (that is, the distance) included in the second distance image information Idst2. Assuming that the bathroom monitoring device A is a generally rectangular parallelepiped bathroom, the predetermined value is set to the diagonal distance of the bathroom.

  In step S42, the CPU 22 replaces the invalid pixel in step S42 with the value of the peripheral valid pixel.

  In step S43, CPU22 extracts the pixel group which comprises outermost periphery from the pixel group which comprises 2nd distance image information Idst2, and recognizes these as the wall surface of a bathroom. Thereafter, after performing perspective projection conversion on the second distance image information Idst2, the CPU 22 searches for a pixel group having a rectangular shape and having substantially the same vertical position by a feature point extraction process. A pixel group farther in the vertical direction with respect to the distance portion 1 is defined as an outline of the washing place 46 of the bathroom 4 (indicated by f in FIG. 14), and a region t2 (see the thick broken line) in the outline is concerned. The second monitoring area information t <b> 2 shown is stored in the nonvolatile memory 23.

  In step S44, the CPU 22 defines the washing place as a second example of the predetermined place, and stores the vertical position in the nonvolatile memory 23 as washing place position information I3 which is another example of bathroom position information.

  13 is different from FIG. 5 in that steps S51 to S511 are included instead of steps S13 to S111. Other than that, there is no difference between the two flow diagrams. Therefore, in FIG. 13, the same step numbers are assigned to the steps corresponding to the steps in FIG.

  In steps S51 and S52, the CPU 22 performs pixel value invalidation processing and replacement processing on the first distance image information Idst1. Since steps S51 and S52 are the same as steps S41 and S42, their descriptions are omitted.

  In step S53, the CPU 22 confirms whether or not there is a person in the washing area. More specifically, the difference between the pixel values belonging to the second monitoring region t2 is calculated in each of the distance images Idst1 and Idst2. If this difference is equal to or greater than a predetermined threshold value, it is determined that there is a person in the washing area.

  If it is determined in step S53 that there is a person in the washing area, the CPU 22 performs perspective projection conversion and feature point extraction processing on the latest frame of the first distance information Idst1 in step S54, thereby determining a predetermined part of the person. The person's head top portion 44, which is an example, is specified, and the vertical position thereof is held as head position information I4, which is an example of person position information.

  In the next step S55, the CPU 22 first reads the washing place position information I3 from the nonvolatile memory 23. Thereafter, the CPU 22 determines whether the vertical position of the top (that is, the latest head position information I4) obtained in step S54 and the vertical position of the washing area (that is, the washing area position information I3) are compared at the washing area. Determine if a person is falling. More specifically, the CPU 22 subtracts the vertical position of the washing area from the vertical position of the top 44 and determines whether or not the difference obtained thereby is equal to or less than a predetermined threshold value. Make a decision. Here, since this bathroom monitoring apparatus D aims at making a fall decision, the threshold is selected to be about 20 cm.

  If it is determined in step S55 that the head has not fallen, the CPU 22 returns to step S51 in order to update the head position information I4, and then repeats the loop of steps S51 to S55. On the other hand, if it is determined to fall, the CPU 22 sets the volume of the warning sound to an initial standard volume in step S56. Thereafter, in step S57, the CPU 22 generates second warning sound data Isnd2, which is one of various warning sound data Isnd and represents a fall warning with a sound of a set volume, and transmits the second warning sound data Isnd2 to the alarm unit 3. The alarm unit 3 outputs a set volume alarm based on the received second alarm sound data Isnd2.

  Next, when it is determined in step S58 that the fourth predetermined time has elapsed since the CPU 22 issued a warning in step S57, the CPU 22 updates the head position information I4 in step S59, and then makes a fall determination in step S510. . In addition, since the process of step S59, S510 is the same as that of step S54, S55, each description is abbreviate | omitted. The fourth predetermined time is selected to be about 10 seconds.

  If it is determined in step S510 that the vehicle has fallen, the CPU 22 regards that the situation is more serious in step S511, sets the volume of the warning sound to be higher than the standard volume, and then performs step S57. By this processing, the warning unit 3 gives a warning by using different methods at intervals. In particular, since the warning volume gradually increases, the care staff can recognize the seriousness of the situation. On the other hand, if it is determined in step S510 that the person has not fallen, it is considered that the person in the bathtub has risen, and the process returns to step S11. Thereafter, the same processing as described above is performed.

  By the way, if it is determined in step S53 that there is no person in the washing area, the CPU 22 determines in step S112 whether or not a fifth predetermined time has elapsed. When the second predetermined time has elapsed in step S112, the CPU 22 considers that no person has entered the washing area for a while and updates the second distance image information Idst2 in step S113. Since the process of step S113 is the same as the process of steps S01 to S03 of FIG. 12, a detailed description will be omitted here. In step S113, it is sufficient that at least the second distance image information Idst2 is updated, but the second monitoring area information t2 or the washing place position information I3 may be updated at the same time.

  After determining that the second predetermined time has not elapsed in step S112 after the process in step S113, the CPU 22 performs step S11 again. Since the subsequent processing is as described above, it will not be described in detail here.

<< 2-2. Effect of Second Embodiment >>
As described above, according to the present embodiment, an alarm can be performed by an extremely simple process of comparing the position d of the top 44 of the person in the bathroom 4 and the position f of the washing place 46 (see FIG. 14). It is possible to provide a bathroom monitoring device D that can be realized at a low cost. Moreover, according to this bathroom monitoring apparatus D, since the camera which produces | generates a normal two-dimensional image is not required, a user's psychological burden is not forced like the description of the 1-3 column.

  In addition, according to the present embodiment, the CPU 22 performs an invalid process of the pixel value on both the distance images Idst1 and Idst2 (steps S41 and S51 in FIGS. 12 and 13) and specularly reflects them with a mirror in the bathroom. The pixel value obtained in is invalidated. In FIG. 15, the bathroom 4 with the mirror 47 is shown, and an invalid pixel value (distance) due to specular reflection is indicated by g. As a result of the above invalidation processing, it is possible to prevent erroneous recognition of the washing area (i.e., the area t2) due to the specular reflection of the distance measuring wave L1 in the bathroom, and the top of the same person can It is possible to prevent recognition from the one-range image Idst1 multiple times. This makes it possible to monitor the bathroom more accurately.

  In step S43, the second monitoring area information t2 defining the washing place is stored in the memory 23, and the outline of the washing place 46 with reference to the distance measuring unit 1 (indicated by f in FIG. 14) is defined. The If the pixel value (distance) of the first distance image information Idst1 acquired in step S51 is outside the outline of the washing place 46 defined in step S43, the CPU 22 may invalidate the pixel value. I can do it.

  Further, similarly to the description in the first to third columns, according to the bathroom monitoring device D, it is possible to reduce the work man-hours of the installer.

  Also in the bathroom monitoring apparatus D, the CPU 22 executes step S52 and subsequent steps only when it is determined in step S51 of FIG. 13 that a person is in the bathroom 4, and therefore, feature point extraction with a large processing load is unnecessary. There is no need to do it.

  Also in the bathroom monitoring device D, since the CPU 22 gives a warning a plurality of times at different volumes over time, it is possible to give a warning according to the severity of the situation.

<< 2-3. Appendix >>
The matters described in the first to fourth columns can be similarly applied to the second embodiment. The second embodiment can be modified similarly to the first to seventh columns. Furthermore, you may combine 1st embodiment and 2nd embodiment.

  In the above embodiment, in step S41, the CPU 22 invalidates a pixel value that is equal to or larger than a predetermined value among the pixel values (that is, the distance) included in the second distance image information Idst2. However, the present invention is not limited to this, and the CPU 22 sequentially selects two distance values in one direction of the uv coordinate system from the second distance image information Idst2, and the change amount of the other distance value with respect to one distance value is a predetermined value. In the above case, the other distance value may be invalidated. In other words, this processing is performed when the CPU 22 determines that the adjacent light receiving element has an amount of change in distance corresponding to one of the plurality of light receiving elements constituting the light receiving unit 13 and the light receiving element adjacent thereto being a predetermined value or more. The corresponding distance is invalidated.

  The bathroom monitoring apparatus and the bathroom monitoring method according to the present invention can be realized at low cost, and can be applied to an apparatus for monitoring a fall or flooding in a bathroom, for example.

A, B, C, D Bathroom monitoring device 1 Distance measuring unit 2 Control unit 22 Processing unit 23 Non-volatile memory 24 Main memory 3 Alarm unit

Claims (5)

A distance measuring unit that obtains distance information including distances to a plurality of locations in the bathroom by emitting a distance measuring wave and receiving a reflected wave in the bathroom by a TOF (Time-of-Flight) method;
A bathroom ranging device comprising: a central processing unit that invalidates a distance greater than or equal to a predetermined value among the distances included in the distance information.   The bathroom range finder according to claim 1, wherein the predetermined value is a diagonal distance of the bathroom. The distance measuring unit is
A plurality of receiving elements arranged in an array in a predetermined direction, each of which outputs a signal indicating a distance to each location in the bathroom;
A signal processing circuit that generates distance information indicating a distance to each location in the bathroom for each of the plurality of receiving elements;
The central processing unit, when a change amount between a distance corresponding to one of the plurality of receiving elements and a distance corresponding to a receiving element adjacent thereto is a predetermined value or more, determines a distance corresponding to the adjacent receiving element. The bathroom range finder according to claim 1, which is invalidated. The distance measurement unit obtains distance information indicating the distance to each location in the bathroom by emitting a distance measurement wave and receiving a reflected wave toward the bathroom where there is no person,
The said central processing part invalidates the distance more than predetermined value among each distance contained in the said distance information acquired when the said distance measurement part does not have a person in the said bathroom. A bathroom distance measuring device according to claim 1. Obtaining distance information including distances to each location in the bathroom by emitting a distance measurement wave in the bathroom and receiving a reflected wave by a TOF (Time-of-Flight) method;
A bathroom ranging method comprising: invalidating a distance greater than or equal to a predetermined value among the distances included in the distance information.

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