A human presence detection method and apparatus

Abstract

The present application relates to a kind of human presence detection method and equipment, the method includes: by TOF sensor to the environment of no one when the environment height detection and environment photon amount detection of to-be-measured environment are carried out, record the environment height and environment photon amount measured;By TOF sensor to the distance detection and photon amount detection of to-be-measured environment in real time actual detection distance and actual detection photon amount are obtained;For each detection result, based on the difference size of environment height and actual detection distance and the difference size of environment photon amount and actual detection photon amount Comprehensive judgment whether there is person in to-be-measured environment.The present application combines the distance detection and photon amount detection of TOF, and the situation of different reflection of human body wearing fabric is comprehensively considered, and the accuracy of human presence detection is improved.

Description

Technical Field

[0001] This invention relates to the field of human body detection, and more particularly to a method and device for detecting the presence of a human body. Background Technology

[0002] Existing human presence detection devices have the following drawbacks:

[0003] (1) No low power consumption function: frequent battery replacement is required for long-term operation;

[0004] (2) No network connectivity: unable to report data to the server and monitor personnel presence in real time through the server;

[0005] (3) No configuration function: The device cannot be configured flexibly and is inconvenient to use;

[0006] (4) Current products have a release problem: PIR technology has a flaw in its principle, and it will release even when the human body is not moving, which cannot be overcome. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes a method and device for detecting the presence of a human body.

[0008] The specific plan is as follows:

[0009] A method for detecting the presence of a human body includes the following steps:

[0010] S1: Use a TOF sensor to detect the ambient height and ambient photon quantity of the test environment when no one is present, and record the measured ambient height and ambient photon quantity;

[0011] S2: The actual detection distance and actual photon quantity are obtained by using a TOF sensor to perform real-time distance and photon quantity detection on the environment under test;

[0012] S3: For each detection result, the presence of a person in the environment is determined by comprehensively considering the difference between the ambient height and the actual detection distance, and the difference between the ambient photon quantity and the actual detection photon quantity.

[0013] Furthermore, the specific determination process of step S3 includes the following steps:

[0014] S311: Determine whether the difference between the ambient height and the actual detection distance is greater than the preset TOF sensor acquisition error. If so, determine that someone is present; otherwise, proceed to S312.

[0015] S312: Determine whether the difference between the ambient height and the actual detection distance is less than the preset minimum height for the presence of a human body. If so, determine that no one is present; otherwise, proceed to S313.

[0016] S313: Determine whether the difference between the actual detected photon quantity and the ambient photon quantity is greater than a times the ambient photon quantity. If so, determine that someone is present; otherwise, proceed to S314.

[0017] S314: Determine whether the difference between the ambient photon quantity and the actual detected photon quantity is greater than b times the ambient photon quantity. If so, determine that someone is present; otherwise, determine that no one is present.

[0018] Among them, 0.5 <b<0.1,0.3<a<0.8。

[0019] Furthermore, the specific determination process of step S3 includes the following steps:

[0020] S321: Determine whether the actual detection distance is less than the preset maximum detection distance. If yes, determine that someone is there; otherwise, proceed to S322.

[0021] S322: Determine whether the difference between the actual detected photon quantity and the ambient photon quantity is greater than a times the ambient photon quantity. If so, determine that someone is present; otherwise, proceed to S323.

[0022] S323: Determine whether the difference between the ambient photon quantity and the actual detected photon quantity is greater than b times the ambient photon quantity. If so, determine that someone is present; otherwise, determine that no one is present.

[0023] Among them, 0.5 <b<0.1,0.3<a<0.8。

[0024] A human presence detection device includes a TOF sensor, a controller, a memory, and a computer program stored in the memory and executable on the controller. When the controller executes the computer program, it implements the steps of the method described in the embodiments of the present invention.

[0025] Furthermore, it also includes a human infrared sensor, which is connected to the controller. When the controller determines that there is someone based on the information received from the human infrared sensor, it controls the TOF sensor to start working. When the controller determines that there is no one based on the information received from the human infrared sensor, it controls the TOF sensor to stop working.

[0026] Furthermore, the human presence detection device is installed on top of or behind where a human body may be present.

[0027] Furthermore, it also includes a wireless communication module for uploading the judgment results to the server.

[0028] The present invention adopts the above technical solution, which combines TOF distance detection and photon quantity detection, and comprehensively considers the situation of the human body wearing fabrics with different reflectivity, thereby improving the accuracy of human presence detection. Attached Figure Description

[0029] Figure 1 The diagram shown is a flowchart of Embodiment 1 of the present invention.

[0030] Figure 2 The diagram shown is a schematic representation of the simulated measurement results for a highly reflective object in this embodiment.

[0031] Figure 3 The diagram shown is a schematic representation of the simulated measurement results for a weakly reflective object in this embodiment. Detailed Implementation

[0032] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention.

[0033] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0034] Example 1:

[0035] This invention provides a method for detecting the presence of a human body, such as... Figure 1 As shown, the method includes the following steps:

[0036] S1: Use a TOF sensor to detect the ambient height and ambient photon quantity of the test environment when no one is present, and record the measured ambient height and ambient photon quantity.

[0037] S2: The actual detection distance and actual photon quantity are obtained by using a TOF sensor to perform real-time distance detection and photon quantity detection of the environment under test.

[0038] S3: For each detection result, the presence of a person in the environment is determined by comprehensively considering the difference between the ambient height and the actual detection distance, and the difference between the ambient photon quantity and the actual detection photon quantity.

[0039] This embodiment uses a bathroom as the environment to be tested, and the specific determination method includes the following steps:

[0040] S311: Determine whether the difference between the ambient height and the actual detection distance is greater than the preset TOF sensor acquisition error. If so, determine that someone is present; otherwise, proceed to S312.

[0041] S312: Determine whether the difference between the ambient height and the actual detection distance is less than the preset minimum height for the presence of a human body. If so, determine that no one is present; otherwise, proceed to S313.

[0042] S313: Determine whether the difference between the actually detected photon amount and the environmental photon amount is greater than a times the environmental photon amount. If so, determine that there is a person; otherwise, proceed to S314;

[0043] S314: Determine whether the difference between the environmental photon amount and the actually detected photon amount is greater than b times the environmental photon amount. If so, determine that there is a person; otherwise, determine that there is no person;

[0044] a and b need to satisfy 0.5 < b < 0.1 and 0.3 < a < 0.8. Those skilled in the art can set the specific values according to experience and test data. In this embodiment, a = 0.5 and b = 0.08. As Figure 2 shown, in step S313, considering the situation where the clothes worn by the human body are strongly reflective and the human body is relatively close to the TOF sensor, the collected photon amount will increase as the distance decreases. Therefore, when the actually detected photon amount is greater than 50% of the photon amount in a no-person environment, it is considered that there is a person. As Figure 3 shown, in step S314, considering that when the clothes worn by the human body are weakly reflective, since part of the photon amount emitted by the TOF sensor will be absorbed by the weakly reflective clothes, when the human body is relatively far from the TOF sensor, when the actually detected photon amount is less than 8% of the photon amount in a no-person environment, it is considered that there is a person.

[0045] The acquisition error of the TOF sensor is related to the TOF sensor and needs to be set in combination with the test results of the TOF sensor for multiple times.

[0046] The setting of the minimum height of the human body is because the human body should have a minimum volume and correspondingly a minimum height. When the difference between the detected environmental height and the actually detected distance is less than this minimum height, it is impossible for the environment to be a human body. Therefore, this height should be set according to the actual situation.

[0047] The above steps S311 - S314 are the implementation manners when the TOF sensor is installed above the human head, that is, installed in the standard mode. In other embodiments, other installation manners can also be adopted, such as the dorsal mode, that is, installed behind the human body. The implementation manner corresponding to step S3 can adopt the following steps:

[0048] S321: Determine whether the actually detected distance is less than the preset maximum detection distance. If so, determine that there is a person; otherwise, proceed to S322;

[0049] S322: Determine whether the difference between the actually detected photon amount and the environmental photon amount is greater than a times the environmental photon amount. If so, determine that there is a person; otherwise, proceed to S323;

[0050] S323: Determine whether the difference between the ambient photon quantity and the actual detected photon quantity is greater than b times the ambient photon quantity. If so, determine that someone is present; otherwise, determine that no one is present.

[0051] In this embodiment, the maximum detection distance is set to 250 centimeters.

[0052] This invention improves the accuracy of human presence detection by combining TOF distance detection and photon quantity detection, and by comprehensively considering the situation of the human body wearing fabrics with different reflectivity.

[0053] Example 2:

[0054] The present invention also provides a human presence detection device, including a TOF sensor, a controller, a memory, and a computer program stored in the memory and executable on the controller. The controller is communicatively connected to the TOF sensor and the memory, and when the controller executes the computer program, it implements the steps in the above-described method embodiment of Embodiment 1 of the present invention.

[0055] Furthermore, the device also includes a human infrared sensor (PIR), which is communicatively connected to the controller. When the controller determines that someone is present based on the information received from the human infrared sensor, it controls the TOF sensor to start working; when the controller determines that no one is present based on the information received from the human infrared sensor, it controls the TOF sensor to stop working.

[0056] By configuring the human infrared sensor, the controller can operate in a low-power mode (TOF sensor stops working) during idle periods and only enter a high-power mode (TOF sensor starts working) during busy periods. The human infrared sensor, a passive human detection technology, is used to decide whether to enter the high-power TOF mode. When the controller is in low-power mode, the overall current draw can be as low as 25μA, thus achieving low power consumption, allowing the 5000mAh battery to last for 3 years.

[0057] In this embodiment, the controller uses an STM32WLE5CC microcontroller, which has several low-power modes: shutdown mode, standby mode, sleep mode, stop1 mode, and stop2 mode. This embodiment uses stop2 mode, in which the RTC timer can periodically wake up the microcontroller. The RTC timer wakes the microcontroller every 13 seconds to perform a watchdog timer, and after processing, it enters stop2 mode for sleep mode. The sleep current in stop2 mode is as low as 25uA, resulting in extremely low power consumption. After entering low-power mode, the device initializes various peripherals and the clock. When the device is powered off, it also shuts down the TOF and PIR power supplies, further reducing power consumption to 10uA.

[0058] Furthermore, the device also includes a wireless communication module for uploading the judgment results to the server. The wireless communication module can be a LoRa wireless module, and the upload conditions can be set by those skilled in the art, such as uploading at a certain period or upon reaching a certain threshold, etc., without limitation here. Real-time data detection can be achieved through real-time uploading.

[0059] Furthermore, since the TOF sensor itself has acquisition errors, and the acquired distance value and photon quantity will change at different times of the day, this embodiment also adds a self-learning mechanism, which is mainly used to update the ambient height and ambient photon quantity at appropriate times to enhance fault tolerance.

[0060] The self-learning mechanism is implemented according to the following logic:

[0061] If the detected status is "occupied" for a continuous period of time, the ambient height and ambient photon quantity are remeasured and updated after n time (e.g., 2 hours) through step S1.

[0062] When the human infrared sensor is idle and the TOF sensor detects that no one is present, the ambient height and ambient photon quantity are remeasured and updated in step S1.

[0063] The embodiments of the present invention have the following beneficial effects:

[0064] 1. Using low-power technology, the battery replacement time can reach 3 years.

[0065] 2. Using wireless communication technology, personnel presence information can be reported to the server at certain intervals, and many devices can be linked to display their presence.

[0066] 3. Using a human infrared sensor for auxiliary human detection and TOF for ranging, it is compatible with various human presence situations and improves the accuracy of human presence detection.

[0067] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A method for detecting the presence of a human body, characterized in that, Includes the following steps: S1: Use a TOF sensor to detect the ambient height and ambient photon quantity of the test environment when no one is present, and record the measured ambient height and ambient photon quantity; S2: The actual detection distance and actual photon quantity are obtained by using a TOF sensor to perform real-time distance and photon quantity detection on the environment under test; S3: For each detection result, the presence of a person in the environment is determined by comprehensively considering the difference between the ambient height and the actual detection distance, and the difference between the ambient photon quantity and the actual detection photon quantity. The specific determination process of step S3 includes the following steps: S311: Determine whether the difference between the ambient height and the actual detection distance is greater than the preset TOF sensor acquisition error. If so, determine that someone is present; otherwise, proceed to S312. S312: Determine whether the difference between the ambient height and the actual detection distance is less than the preset minimum height for the presence of a human body. If so, determine that no one is present; otherwise, proceed to S313. S313: Determine whether the difference between the actual detected photon quantity and the ambient photon quantity is greater than a times the ambient photon quantity. If so, determine that someone is present; otherwise, proceed to S314. S314: Determine whether the difference between the ambient photon quantity and the actual detected photon quantity is greater than b times the ambient photon quantity. If so, determine that someone is present; otherwise, determine that no one is present. Where 0.08 ≤ b < 0.1, 0.3 <a<0.8; The specific determination process of step S3 includes the following steps: S321: Determine whether the actual detection distance is less than the preset maximum detection distance. If yes, determine that someone is there; otherwise, proceed to S322. S322: Determine whether the difference between the actual detected photon quantity and the ambient photon quantity is greater than a times the ambient photon quantity. If so, determine that someone is present; otherwise, proceed to S323. S323: Determine whether the difference between the ambient photon quantity and the actual detected photon quantity is greater than b times the ambient photon quantity. If so, determine that someone is present; otherwise, determine that no one is present. Where 0.08 ≤ b < 0.1, 0.3 <a<0.8。 2. A human presence detection device, characterized in that: It includes a TOF sensor, a controller, a memory, and a computer program stored in the memory and running on the controller, wherein the controller executes the computer program to implement the steps of the method as claimed in claim 1.

3. The human presence detection device according to claim 2, characterized in that: It also includes a human infrared sensor, which is connected to the controller. When the controller determines that there is someone based on the information received from the human infrared sensor, it controls the TOF sensor to start working. When the controller determines that there is no one based on the information received from the human infrared sensor, it controls the TOF sensor to stop working.

4. The human presence detection device according to claim 2, characterized in that: The human presence detection device is installed on top of or behind where a human body may be present.

5. The human presence detection device according to claim 2, characterized in that: It also includes a wireless communication module for uploading the judgment results to the server.

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