Person location detection apparatus and air conditioner

• US 20090210193A1
• Filed: 01/23/2009
• Published: 08/20/2009
• Est. Priority Date: 01/28/2008
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Nagase, Keiji
• Granted Patent: US 8,326,571 B2
• Time in Patent Office: Days
• US Class Current: 702/152
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/64 using pre-stored data
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 11/79 for controlling the direction of the supplied air
• CPC Class Codes: F24F 2120/10 Occupancy
• CPC Class Codes: F24F 2120/12 Position of occupants

Abstract

A person location detecting apparatus according to the present invention includes a light emitting section for radiating a projection light and a TOF method distance image sensor for receiving a reflected light from a room space of the projection light to output distance information in accordance with a distance to an object in the room space from each of a plurality of light receiving sections, and further includes a distance change detecting section for detecting a distance change to the object in the room space based on the distance information from the TOF method distance image sensor and a person distinguishing section for distinguishing a person by specifying a shape of a detected distance change area to detect a direction and distance to the distance change area that is specified as a shape of a person as a location of a person.

Claims

1. A person location detecting apparatus comprising a light emitting section for radiating a projection light and a TOF (Time Of Flight) method distance image sensor for receiving a reflected light from a room space of the projection light to output distance information in accordance with a distance to an object in the room space from each of a plurality of light receiving sections,

the person location detecting apparatus further comprising a distance change detecting section for detecting a distance change to the object in the room space based on the distance information from the TOF method distance image sensor and a person distinguishing section for distinguishing a person by identifying a shape of a detected distance change area to detect a direction and distance to the distance change area that is identified as a shape of a person as a location of a person.

2. A person location detecting apparatus according to claim 1, wherein the distance change detecting section measures a distance to the object in the room space in real time, calculates a time change amount of each distance in the room space based on each measured distance in the room space, and detects an existence and non-existence of a distance change based on whether or not the time change amount is less than a predetermined threshold.

3. A person location detecting apparatus according to claim 2, wherein the distance change detecting section includes a distance balanced state determining section for measuring a time change amount of a distance to the object in the room space in real time, and determining that the distance in the room is in a balanced state by the measured time change amount of the distance becoming asymptotic to zero.

4. A person location detecting apparatus according to claim 3, wherein the determining that the distance is in a balanced state corresponds to a case where there is no change in the location of the object.

5. A person location detecting apparatus according to claim 2, wherein the distance change detecting section includes a distance change state determining section for calculating a distance difference value of a frame distance value of the room space in a distance balanced state and each frame distance value from the TOF method distance image sensor to determine that the distance in the room is in a changing state when the distance difference value is greater than or equal to a predetermined threshold value and continues for a set time or more.

6. A person location detecting apparatus according to claim 5, wherein the distance difference value sets a distance frame difference threshold value for each measurement distance range in accordance with a distance resolution of the TOF method distance image sensor, and maintains the distance frame difference threshold value in a predetermined recording section in a table in order to improve an accuracy for determining a distance change.

7. A person location detecting apparatus according to claim 1, wherein the person distinguishing section distinguishes a person by comparing a value indicating a characteristic of a registered shape of a person with regard to a moving state and a still state of a person, such as a standing state, a sitting state, a lying state, and a figure difference and a value indicating a characteristic of a shape of the detected distance change area.

8. A person location detecting apparatus according to claim 7, wherein the value indicating the characteristic of the registered shape of the person is normalized by dividing a human body into each part of a trunk, a leg, and an arm and calculating a ratio of a short side length and a long side length in each part of the human body.

9. A person location detecting apparatus according to claim 8, wherein the value indicating the characteristic of the registered shape of the person is determined by calculating at least a maximum value and a minimum value and determining an indicated value range of a shape characteristic pattern from the maximum value and the minimum value.

10. A person location detecting apparatus according to claim 8, wherein the value indicating the characteristic of the registered shape of the person is determined by calculating at least a maximum value, a minimum value and an average value as well as calculating a standard deviation value using the average value, determining an indicated value range of a shape characteristic pattern from the maximum value and the minimum value, and determining a degree of variation of a shape characteristic pattern from the standard deviation value.

11. A person location detecting apparatus according to claim 1, wherein the light emitting section radiates a near infrared pulse light at a constant cycle as the projection light to the room space.

12. A person location detecting apparatus according to claim 1, wherein the light receiving section includes a photoelectric conversion section in a middle, and two pixel output electrodes V1 and V2 at points with point symmetry with respect to a center of the photoelectric conversion section interposed therebetween with two electric charge transfer gates for inputting gate signals that are contrary to each other, and outputs from the two pixel output electrodes V1 and V2 signal charges divided depending on a flight time of light corresponding to a distance to the object as the distance information.

13. A person location detecting apparatus according to claim 12, wherein the signal charges from the two pixel output electrodes V1 and V2 are converted into output voltage information in accordance with the distance and outputted from the TOF method distance image sensor as the distance information.

14. A person location detecting apparatus according to claim 1, wherein the distance L to the distance change area, the shape of which is identified as the person, is estimated by detecting the flight time T of the light to the person, and by letting c be a known speed of the light from L=(½

)·

c·

T.

15. An air conditioner for detecting a location (direction and distance) of a person using the person location detecting apparatus according to claim 1, and for performing an air conditioning in accordance with the detected location of the person.