Human presence detection method using radio waves in a closed space

Abstract

In enclosed spaces such as unit bathrooms, which are composed of ceilings, floors, walls, windows, and doors containing metal, detecting a person's position and movement using radio waves presents a challenge: the reflection of radio waves by metal causes a significant time for attenuation, making it difficult to obtain the same results as in open spaces. [Solution] In a closed space consisting of ceilings, floors, walls, windows, doors, etc. containing metal, with one or more radio wave sensors installed, the total amount of radio wave reflection at multiple detection distances when the space is unoccupied is measured and stored as a baseline value. The total amount of radio wave reflection at multiple detection distances when the space is occupied (i.e., when the space is occupied) is measured and recorded as a measured value. By comparing this measured value with the baseline value, a method is used to detect the position and movement of a person using radio waves, taking advantage of the characteristic that the radio wave attenuation time is longer due to reflection of radio waves by metal. This makes it easy to detect the position and movement of a person using radio waves even in a closed space consisting of ceilings, floors, walls, windows, doors, etc. containing metal.

Description

Technical Field

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[0001] The present invention relates to a human presence detection method using radio waves in a closed space.

Background Art

[0002] There are infrared, radio wave, and image processing methods for electronically executed human presence detection methods.

[0003] The radio wave method is a method of receiving a radio wave reflection wave in which a transmitted radio wave is reflected by an object.

[0004] The radio wave method has the feature of being able to detect objects at different overlapping distances and is applied to many products. <00​​​​​​​​​​​​​​​​​​​​​​​​​​​​ [Patent Document 1] Japanese Patent Application No. 2023-185131 [Overview of the project] [Problems that the invention aims to solve]

[0011] In enclosed spaces such as unit bathrooms, which are composed of ceilings, floors, walls, windows, and doors containing metal, detecting a person's position and movement using radio waves presents a challenge: the reflection of radio waves by metal causes significant attenuation time, making it difficult to obtain the same results as in open spaces. Therefore, detecting a person's position and movement using radio waves is not easy. [Means for solving the problem]

[0012] This invention is a method that utilizes the characteristic that a difference arises between the measured total amount of radio wave reflection at multiple detection distances when a person is present (i.e., when a person is present) and the baseline value of the total amount of radio wave reflection at multiple detection distances when the room is unoccupied, in a closed space such as a unit bathroom that is composed of ceilings, floors, walls, windows, doors, etc. that contain metal.

[0013] By utilizing this characteristic, comparing the measured total amount of radio wave reflection at multiple detection distances when a person is present with the baseline value of the total amount of radio wave reflection at multiple detection distances when no one is present, it is possible to reduce the characteristic that radio waves take time to attenuate when reflected by ceilings, floors, walls, windows, doors, etc., which contain metal. This makes it possible to detect the position and movement of people using radio waves even in enclosed spaces composed of ceilings, floors, walls, windows, doors, etc., which contain metal.

[0014] Using multiple radio wave sensors in an unoccupied state, the total amount of radio wave reflection at multiple detection distances is measured and recorded multiple times. Based on the radio wave reflection characteristics of the enclosed space composed of ceilings, floors, walls, windows, doors, etc., including metal, a baseline value of the total amount of radio wave reflection at multiple detection distances in an unoccupied state is determined by peak detection, the average of the standard deviations, or other numerical calculation arithmetic.

[0015] When a person is present, multiple radio wave sensors are used to measure and record the total amount of radio wave reflection at multiple detection distances, and the measured value of the total amount of radio wave reflection at multiple detection distances is determined.

[0016] When comparing the measured values of the total amount of radio wave reflection for multiple detection distances during occupancy with the baseline values of the total amount of radio wave reflection for multiple detection distances when unoccupied, the characteristic of the radio wave attenuation time being long due to the reflection of radio waves by ceilings, floors, walls, windows, doors, etc. containing metal can be reduced, and the position and movement of people can be detected by radio wave method even in an enclosed space composed of ceilings, floors, walls, windows, doors, etc. containing metal.

Advantages of the Invention

[0017] When detecting the position and movement of people by radio waves, in an enclosed space composed of ceilings, floors, walls, windows, doors, etc. containing metal, such as a unit bus where the radio wave attenuation time is long due to reflection of radio waves by metal and it is difficult to obtain the same results as in free space, the detection of the position and movement of people by radio wave method becomes easier.

[0018] This means that it is possible to distinguish between unoccupied and occupied states in an enclosed space composed of ceilings, floors, walls, windows, doors, etc. containing metal.

[0019] When the unoccupied state continues for a long time, updating the baseline value of the total amount of radio wave reflection for multiple detection distances when unoccupied makes it possible to maintain more accurate detection.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is an explanatory diagram of a human presence detection method by radio wave method in an enclosed space. (Example)

Modes for Carrying Out the Invention

[0021] The human presence detection method by radio wave method of the present invention uses radio wave sensors 1 and 2 equipped with a reference radio wave oscillator, a radio wave transmitter, a transmission antenna unit, a reception antenna unit, a radio wave receiver, an IQ signal processing unit, a distance calculation unit, a movement calculation unit, a reflected wave memory unit, and a power supply unit.

[0022] The radio wave type sensors 1 and 2 are installed on the ceiling, walls, etc., and measure the total amount of radio wave reflection for each of a plurality of detection distances within a structure having protrusions such as a ceiling, wall, floor containing metal and a bathtub 4, i.e., within a closed space 3.

[0023] The measurement within the closed space 3 is carried out when无人时 (无人時 is not a recognized Chinese term, it might be a misspelling. Assuming it means "when无人时 (无人 means no one, so when no one is present)" in Chinese, which is translated as "when无人时 (无人 means no one, so when no one is present)" in Chinese, which is translated as "when no one is present") and when a person 5 enters and moves, i.e., when有人时 (有人 means someone, so when someone is present)" in Chinese, which is translated as "when someone is present".

[0024] When comparing the measured values of the total amount of radio wave reflection for each of a plurality of detection distances when someone is present, which is the result of this, with the base values of the total amount of radio wave reflection for each of a plurality of detection distances when no one is present, it is possible to reduce the characteristic that the radio wave attenuation time takes time due to reflection by metal of the radio wave, and it is possible to detect the position and movement of a person by the radio wave method even in a closed space composed of a ceiling, floor, wall, window, door, etc. containing metal.

[0025] When无人时 (无人 means no one, so when无人时 (无人 means no one, so when no one is present)" in Chinese, which is translated as "when无人时 (无人 means no one, so when no one is present)" in Chinese, which is translated as "when no one is present" continues for a long time, the base value of the total amount of radio wave reflection for each of a plurality of detection distances when无人时 (无人 means no one, so when无人时 (无人 means no one, so when no one is present)" in Chinese, which is translated as "when无人时 (无人 means no one, so when no one is present)" in Chinese, which is translated as "when no one is present" can be updated to maintain accurate detection.

Industrial Applicability

[0026] The embodiment of FIG. 1 shows that in a closed space composed of a ceiling, floor, wall, window, door, etc. containing metal such as in a unit bathroom, even in a situation where it is difficult to obtain results approximated to theories such as the radio wave propagation theory and radio wave attenuation theory in free space, it is possible to detect the position and movement of a person by the radio wave method using an IQ signal by the radio wave method, and further shows the possibility of expanding the usage range of radio waves.

Explanation of Signs

[0027] 1 Radio wave type sensor 2 Radio wave type sensor 3 Closed space <00001​​​

Claims

[Claim 1] A method for detecting a person's position and movement using radio waves, in a closed space composed of ceilings, floors, walls, windows, doors, etc. containing metal, in which one or more radio wave sensors are installed, each comprising at least a reference radio wave oscillator, a radio wave transmitter, a transmitting antenna, a receiving antenna, a radio wave receiver, an IQ signal processing unit, a distance calculation unit, a movement calculation unit, a reflected wave memory unit, and a power supply unit, is used. The total amount of reflected radio waves at multiple detection distances when the room is unoccupied is measured and stored as a baseline value, and the total amount of reflected radio waves at multiple detection distances when a person enters or moves, i.e., when the room is occupied, is measured and stored as a measured value. By comparing this measured value with the baseline value, the characteristic that radio waves reflect off metal such as ceilings, walls, and floors take time to attenuate is reduced, thereby enabling the detection of a person's position and movement using radio waves.

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