WO2020182099A1

WO2020182099A1 - Pir sensor signal triggering method and device

Info

Publication number: WO2020182099A1
Application number: PCT/CN2020/078459
Authority: WO
Inventors: 吴肇杰; 黄海江
Original assignee: 杭州海康威视数字技术股份有限公司
Priority date: 2019-03-11
Filing date: 2020-03-09
Publication date: 2020-09-17
Also published as: CN111696289B; CN111696289A

Abstract

Disclosed are a PIR sensor signal triggering method and device. The method comprises: setting a first voltage threshold and a second voltage threshold; generating a triggering signal within a preset time duration range starting timing at the moment while a monitoring signal generated by a PIR sensor reaches the first voltage threshold and when the number of times that the monitoring signal generated by the PIR sensor alternatively reaches the first voltage threshold and the second voltage threshold reaches a set number of times. The first voltage threshold and the second voltage threshold are voltage thresholds that a waveform generated by a human body on the PIR sensor can reach the set number of times within the preset time duration range and waveforms generated by other heat sources other than the human body on the PIR sensor cannot reach the set number of times within the preset time duration range. The present application achieves the accurate recognition and signal triggering of the waveform for the human body by using the characteristic of different waveforms generated by the heat sources such as the human body and hot air on the PIR sensor.

Description

A PIR sensor signal trigger method and device

This application claims the priority of the Chinese patent application filed with the Chinese Patent Office on March 11, 2019 with the application number 201910178824.0 and the invention titled "A method and device for triggering PIR sensor signals", the entire content of which is incorporated into this application by reference in.

Technical field

This application relates to the field of security technology, in particular to a method and device for triggering PIR sensor signals.

Background technique

The working principle of the PIR (Passive Infrared Ray, pyroelectric infrared sensor) sensor is to focus the human body's thermal radiation on the pyroelectric element through a lens, so that the pyroelectric element changes in level with the change of the heat radiation. By monitoring the level change, the alarm in the installation environment of the PIR sensor can be realized. For example, when a person enters the monitoring area of the PIR sensor, the PIR sensor is prompted to produce a level change, and then an alarm is triggered by the level change of the PIR sensor.

However, because the PIR sensor is a component that passively monitors the level of thermal radiation, when a heat source similar to human thermal radiation is generated in the area monitored by the PIR sensor, an alarm will be triggered falsely, which limits the application of the PIR sensor. The heat radiation generated by non-human heat sources such as hot air has a wavelength similar to that of the human body. It can also be collected by the PIR sensor and output a level similar to or higher than that triggered by human heat radiation, so that when hot air blows through the PIR sensor, Make the PIR sensor trigger an alarm. Therefore, PIR sensors can hardly be used in outdoor environments.

Summary of the invention

In view of this, the present application provides a PIR sensor signal triggering method and device to generate an accurate human body monitoring trigger signal based on the monitoring signal of the PIR sensor, and avoid false signal triggering caused by interference such as hot air.

The technical solution of this application is realized as follows:

A PIR sensor signal trigger method, including:

Setting the first voltage threshold and the second voltage threshold;

Within the preset time range from the moment when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold and the second voltage threshold. When the number of voltage threshold reaches the set number of times, a trigger signal is generated.

Further, the PIR sensor is a bipolar PIR sensor.

Further, the monitoring signal generated by the PIR sensor is generated by the PIR sensor and amplified by an operational amplifier circuit electrically connected to the PIR sensor.

Further, the first voltage threshold is greater than the second voltage threshold; or

The first voltage threshold is less than the second voltage threshold.

Further, the duration of the preset time range belongs to a duration range of 2 seconds to 6 seconds.

Further, the set number of times is 2 times, or 3 times, or 4 times.

Further, the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold and the first voltage threshold within the preset time range that is counted when the monitoring signal generated by the PIR sensor reaches the first voltage threshold. When the number of times of the second voltage threshold reaches a set number of times, generating a trigger signal includes:

Within the preset time range from when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, whenever it is detected that the monitoring signal generated by the PIR sensor reaches the first voltage threshold, and In the previous count, it was detected that the monitoring signal generated by the PIR sensor reached the second voltage threshold, and the number of times the monitoring signal generated by the PIR sensor reached the threshold was increased by 1, and whenever the PIR was detected The monitoring signal generated by the sensor reaches the second voltage threshold, and in the previous count, it was detected that the monitoring signal generated by the PIR sensor reached the first voltage threshold, and it was recorded that the monitoring signal generated by the PIR sensor reached The number of thresholds is increased by one, and the number of times the monitoring signal generated by the PIR sensor reaches the threshold is the first time when starting to count and record;

When the recorded number of times the monitoring signal generated by the PIR sensor reaches the threshold reaches the set number of times, a trigger signal is generated.

It can be seen from the above solution that the PIR sensor signal triggering method and device of the present application uses the characteristics of different shapes of the human body and heat sources such as hot air to generate different waveforms for the PIR sensor, and is based on the waveform generated by the human body to the PIR sensor. By setting the first voltage threshold and the second voltage threshold, when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold and When the number of times of the second voltage threshold reaches the set number of times, a trigger signal is generated, thereby realizing accurate identification of the human body waveform and signal triggering. Among them, the waveform generated by the human body to the PIR sensor can alternately reach the first voltage threshold and the second voltage threshold within the preset time range, and the heat source such as hot air cannot alternately reach the first voltage threshold and the first voltage threshold within the preset time range. Two voltage threshold setting times, through this voltage threshold setting, the recognition of the human body waveform is realized. The PIR sensor signal trigger method and device of the present application can be applied to the existing bipolar PIR sensor equipment, and there is no need to modify the existing bipolar PIR sensor equipment, only the signal of the existing bipolar PIR sensor equipment The output terminal can be connected to the device that realizes the PIR sensor signal trigger method and device function of the embodiment of the present application, and has high compatibility with the existing bipolar PIR sensor equipment, and there is no need for the existing bipolar PIR sensor equipment The transformation saves the investment in the transformation of the existing bipolar PIR sensor equipment.

Description of the drawings

The drawings here are incorporated into the specification and constitute a part of the specification, show embodiments that conform to the application, and are used together with the specification to explain the principle of the application. In the attached picture:

FIG. 1 is a flowchart of a method for triggering a PIR sensor signal according to an embodiment of the application;

FIG. 2 is a structural diagram of a PIR sensor signal trigger device according to an embodiment of the application;

Figure 3 is a schematic diagram of the structure of an existing bipolar PIR sensor device;

Figure 4 is a schematic diagram of the waveform change of the existing bipolar PIR sensor equipment caused by hot air;

Fig. 5 is a schematic diagram of the waveform changes caused by the human body to the existing bipolar PIR sensor equipment;

FIG. 6 is the relationship between the voltage offset value, the first voltage threshold value and the second voltage threshold value set in the embodiment of the application;

7 is a schematic diagram of recording X1 point when the interference waveform reaches the first voltage threshold in the embodiment of the application;

8 is a schematic diagram of recording X2 points when the interference waveform reaches the second voltage threshold in the embodiment of the application;

9 is a schematic diagram of recording X3 point when the interference waveform in the embodiment of the application reaches the first voltage threshold again;

10 is a schematic diagram of recording X4 points when the interference waveform reaches the second voltage threshold again in the embodiment of the application;

FIG. 11 is a logic flow chart when the number of times n is set to 3 in an embodiment of the application;

Through the above drawings, the specific embodiments of the present application have been shown, which will be described in more detail below. These drawings and text description are not intended to limit the scope of the concept of the present application in any way, but to explain the concept of the present application to those skilled in the art by referring to specific embodiments.

detailed description

In order to make the purpose, technical solutions, and advantages of this application clearer, the following will further describe this application in detail with reference to the drawings and embodiments.

As shown in Fig. 1, the method for triggering a PIR sensor signal in an embodiment of the present application includes:

Step 1. Set the first voltage threshold and the second voltage threshold;

Step 2. Within the preset time range when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, the number of times the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold and the second voltage threshold reaches the set When the number of times, a trigger signal is generated.

Wherein, the starting time of the preset time range is the time when the monitoring signal generated by the PIR sensor reaches the first voltage threshold. According to the duration of the preset time range, the end time of the preset time range can be determined. For example, if the duration of the preset time range is 2 seconds, the end time of the preset time range is to start timing when the monitoring signal reaches the first voltage threshold The next 2 seconds correspond to the moment.

The setting of the first voltage threshold and the second voltage threshold ensures that the number of times that the waveform generated by the human body to the PIR sensor alternately reaches the first voltage threshold and the second voltage threshold within the preset time range can reach the set number of times; except for the human body The waveform generated by other heat sources (such as hot air) to the PIR sensor cannot alternately reach the first voltage threshold and the second voltage threshold within the preset time range, and/or other heat sources other than the human body (such as hot air) The number of times that the waveform generated by the PIR sensor alternately reaches the first voltage threshold and the second voltage threshold cannot reach the set number of times. Through this voltage threshold setting, the recognition of the human body waveform is realized.

In an alternative embodiment, the trigger signal can be sent to multiple devices to trigger the operation of the corresponding device. For example, the trigger signal can be sent to the alarm device to trigger the alarm of the alarm device, and the trigger signal can also be sent to the light control device to trigger the lighting of the electric light.

In an alternative embodiment, the PIR sensor may be a bipolar PIR sensor.

In an alternative embodiment, the monitoring signal generated by the PIR sensor is generated by the PIR sensor and amplified by an operational amplifier circuit electrically connected to the PIR sensor.

In an alternative embodiment, the first voltage threshold is greater than the second voltage threshold; or, the first voltage threshold is less than the second voltage threshold.

In an optional embodiment, the duration of the preset time range belongs to a duration range of 2 seconds to 6 seconds.

For example, when the duration of the preset time range is 2 seconds, it can be detected that the monitoring signal generated by the PIR sensor alternately reaches the first voltage within 2 seconds from the moment when the monitoring signal generated by the PIR sensor reaches the first voltage threshold. Whether the number of thresholds and the second voltage threshold reaches the set number of times.

Or, when the length of the preset time range is 6 seconds, it can be detected that the monitoring signal generated by the PIR sensor alternately reaches the first voltage within 6 seconds from the moment when the monitoring signal generated by the PIR sensor reaches the first voltage threshold. Whether the number of thresholds and the second voltage threshold reaches the set number of times.

In an alternative embodiment, the set number of times is 2, or 3 times, or 4 times.

For example, when the set number of times is 2, it can be detected that the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold within the preset time range from the moment the monitoring signal generated by the PIR sensor reaches the first voltage threshold. And the number of times the second voltage threshold has reached 2 times.

Or, when the set number of times is 4, it can be detected that the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold within the preset time range from the moment when the monitoring signal generated by the PIR sensor reaches the first voltage threshold. And the number of times the second voltage threshold has reached 4 times.

In an optional implementation, the above step 2 may include the following steps: within a preset time range starting from the moment when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, whenever the monitoring signal generated by the PIR sensor reaches The first voltage threshold, and the detection signal generated by the PIR sensor reaches the second voltage threshold during the previous count, the number of times the monitoring signal generated by the PIR sensor reaches the threshold is increased by one, and each time the PIR sensor is detected The generated monitoring signal reaches the second voltage threshold, and it was detected that the monitoring signal generated by the PIR sensor reached the first voltage threshold during the previous count. The number of times that the monitoring signal generated by the PIR sensor reaches the threshold is increased by one; when the recorded When the number of times the monitoring signal generated by the PIR sensor reaches the threshold reaches the set number of times, a trigger signal is generated.

Among them, the number of times that the monitoring signal generated by the PIR sensor reaches the threshold value is the first time when the timing is started.

For example, the set number of times is 4, and the duration of the preset time range is 6 seconds.

When it is detected that the monitoring signal generated by the PIR sensor reaches the first voltage threshold, start timing, and record the number of times the monitoring signal generated by the PIR sensor reaches the threshold as the first time.

When it is detected that the monitoring signal generated by the PIR sensor reaches the second voltage threshold, if the current timing time does not reach 6 seconds, the number of times the monitoring signal generated by the PIR sensor reaches the threshold can be recorded as the second time. If the current timing time When it reaches 6 seconds, you can stop timing and counting.

In the case that the number of times that the monitoring signal generated by the PIR sensor reaches the threshold is the second time, afterwards, when the monitoring signal generated by the PIR sensor is detected to reach the first voltage threshold again, if the current timing time does not reach 6 seconds , It can record the number of times that the monitoring signal generated by the PIR sensor reaches the threshold as the third time. If the current timing time reaches 6 seconds, you can stop timing and stop counting.

In the case that the number of times that the monitoring signal generated by the PIR sensor reaches the threshold is the third time, afterwards, when the monitoring signal generated by the PIR sensor is detected to reach the second voltage threshold again, if the current timing time does not reach 6 seconds , Record the number of times that the monitoring signal generated by the PIR sensor reaches the threshold value as the fourth time, that is, the set number of times, at this time, a trigger signal can be generated.

The embodiment of the present application also provides a PIR sensor signal triggering device, as shown in FIG. 2, including a setting module 11, a recording module 12 and a signal triggering module 13. The setting module 11 is used to set the first voltage threshold and the second voltage threshold. The recording module 12 is used for recording the number of times that the monitoring signal generated by the PIR sensor reaches the first voltage threshold and the second voltage threshold alternately within the preset time range when the monitoring signal generated by the PIR sensor reaches the first voltage threshold. . The signal trigger module 13 is used to generate a trigger signal when the number of times the monitoring signal generated by the PIR sensor recorded by the recording module 12 alternately reaches the first voltage threshold and the second voltage threshold reaches a set number of times.

The PIR sensor alarm method and device in the embodiments of the present application are applicable to existing bipolar PIR sensor equipment. Figure 3 shows a schematic structural diagram of an existing bipolar PIR sensor device. The bipolar PIR sensor device includes an optical component 21, a pyroelectric element 22, a MOS tube 23 and an operational amplifier 24. The optical component 21 includes a lens 211 and a filter 212, where the filter 212 is, for example, a Fresnel filter array, where the Fresnel filter array is equivalent to multiple lenses. The pyroelectric element 22 includes a first pyroelectric element 221 and a second pyroelectric element 222. The first pyroelectric element 221 and the second pyroelectric element 222 are connected with the same polarity, as shown in FIG. 3, for example, The positive electrode of the first pyroelectric element 221 and the positive electrode of the second pyroelectric element 222 are connected. The gate G of the MOS tube 23 is connected to the negative electrode of one of the two pyroelectric elements, and the negative electrode of the other pyroelectric element is grounded. For example, as shown in FIG. 3, the gate G of the MOS tube 23 is connected The negative electrode of the first pyroelectric element 221, and the negative electrode of the second pyroelectric element 222 is grounded to GND. The source S of the MOS tube 23 is connected to the input terminal of the operational amplifier 24, and the drain D of the MOS tube 23 is connected to the power supply voltage. The output terminal of the operational amplifier 24 outputs the monitoring signal of the PIR sensor.

The thermal radiation emitted from the outside passes through the optical assembly 21 and is focused on the first pyroelectric element 221 and the second pyroelectric element 222. When the thermal radiation energy received by the first pyroelectric element 221 and the second pyroelectric element 222 is At the same time, the energies cancel each other out, so that no electrical signal output is generated, and the source S of the MOS transistor 23 only outputs the voltage of the bias value. Only when the heat radiation energy received by the first pyroelectric element 221 and the second pyroelectric element 222 are different, an electrical signal is output, when the radiation irradiated to the second pyroelectric element 222 is greater than that of the first pyroelectric element 222 When element 221, the source S of the MOS tube 23 outputs a voltage higher than the bias value. When the radiation irradiated to the second pyroelectric element 222 is smaller than the first pyroelectric element 221, the source S of the MOS tube 23 outputs Voltage below the offset value. When the human body passes through the bipolar PIR sensor device, the human body heat radiation is focused on the first pyroelectric element 221 and the second pyroelectric element 222 through an equivalent lens in the Fresnel filter array, MOS The tube 23 will output positive bias voltage, 0, negative bias voltage, and 0. When the human body passes through the next equivalent lens in the Fresnel filter array, it is focused on the first pyroelectric element 221 and the second pyroelectric element 221 and the second pyroelectric element. When the electric element 222 is on, the output signal of the MOS tube 23 repeats the previous signal cycle and outputs a positive bias voltage, 0, a negative bias voltage, and 0. Because the voltage amplitude output by the source S of the MOS tube 23 is very low, it needs to be amplified by the operational amplifier 24 to be detected. In the embodiment of the present application, the signal amplified by the operational amplifier 24 is defined as a PIR sensor The generated monitoring signal.

Existing bipolar PIR sensor equipment, once the oscillation amplitude of the monitoring signal is higher than a set threshold or lower than another set threshold, it is determined that there is human activity, and a trigger signal is generated to perform operations such as alarms. For this trigger Mode, indoor applications will not cause false alarms, but once used in outdoor environments, it is very susceptible to the interference of sunlight and hot air to produce false alarms, due to the heat radiation wavelength generated by non-human heat sources such as hot air and the heat generated by the human body The radiation is similar, can also be collected by the pyroelectric element, and can output a level similar to or higher than that triggered by the human body's thermal radiation, and then can reach the above-mentioned higher than a set threshold or lower than another set. The effect of setting the threshold, which in turn generated false alarms.

In the actual test, the inventor found that the waveform generated by the hot air in the external environment is not the same as the waveform generated by the human body. For hot air, due to the larger volume of the wind, the projected area after passing through the lens is larger. Since the first pyroelectric element 221 and the second pyroelectric element 222 are connected in reverse series, the energy incident at the same time will cancel each other out. Only at the initial stage of the hot air, the voltage has a positive or negative change. The group gradually approaches the middle offset value, as shown in Figure 4.

As for the human body, the volume of the human body is small, and in actual use, the filter 212 often adopts a Fresnel filter array (ie multiple Fresnel lenses), or the filter 212 adopts an inner surface as The lens array is composed of small ball lenses, so the projected area of the human body after passing through the lens is small. Since the first pyroelectric element 221 and the second pyroelectric element 222 are connected in reverse series, when the incident energy is sequentially irradiated on the first When a pyroelectric element 221 and a second pyroelectric element 222 are connected, the voltage waveform generated will form a waveform that alternately changes around the intermediate bias value, as shown in FIG. 5. Therefore, by judging the characteristics of this waveform, the bipolar PIR sensor device can distinguish the human body in an outdoor environment and reduce the false alarm of the PIR sensor device.

The embodiment of this application is based on the difference in the characteristics of the interference waveform formed by the human body and the hot air on the bipolar PIR sensor device, especially the trigger signal is generated based on the characteristics of the interference waveform formed by the human body on the bipolar PIR sensor device. The embodiment mainly includes the following steps.

1) The interference waveform signal formed by the PIR sensor device is an AC signal with a bias. First, determine the voltage bias value V _{0 of the} signal.

2) Determine the first voltage threshold V ₁ and the second voltage threshold V ₂ according to the actual detection range requirements, as shown in FIG. 6. Wherein, the first voltage threshold V _{1 is} higher than the voltage offset value V ₀ , and the second voltage threshold V _{2 is} lower than the voltage offset value V ₀ . In other embodiments, the first voltage threshold V ₁ may be lower than the voltage offset value V ₀ , and the second voltage threshold V ₂ may be higher than the voltage offset value V ₀ .

3) When the interference waveform formed by the human body to the bipolar PIR sensor device reaches the first voltage threshold value V ₁ or the second voltage threshold value V ₂ , the number of times of reaching the threshold value is recorded once and the timing is started. For example, in the embodiment shown in FIG. 7, when the interference waveform formed by the human body on the bipolar PIR sensor device reaches the first voltage threshold V ₁ (high threshold), point X ₁ is recorded and the timing is started.

4) After that, when the interference waveform formed by the human body to the bipolar PIR sensor device reaches the second voltage threshold V ₂ or the first voltage threshold V ₁ , record the number of times reaching the threshold again, and at this time it has been recorded twice The number of times the threshold has been reached. For example, in the embodiment shown in FIG. 8, when the interference waveform formed by the human body to the bipolar PIR sensor device reaches the second voltage threshold V ₂ (low threshold), X ₂ points are recorded.

5) After that, when the interference waveform formed by the human body on the bipolar PIR sensor device reaches the first voltage threshold V ₁ or the second voltage threshold V ₂ again, the number of reaching the threshold is recorded once again, and 3 is already recorded at this time The number of times the threshold is reached. For example, in the embodiment shown in FIG. 9, when the interference waveform formed by the human body on the bipolar PIR sensor device reaches the first voltage threshold V ₁ (high threshold) again, X ₃ points are recorded.

6) After that, when the interference waveform formed by the human body on the bipolar PIR sensor device reaches the second voltage threshold V ₂ or the first voltage threshold V ₁ again, the number of times reaching the threshold is recorded again, and 4 has been recorded at this time The number of times the threshold is reached. For example, in the embodiment shown in FIG. 10, when the interference waveform formed by the human body to the bipolar PIR sensor device reaches the second voltage threshold V ₂ (low threshold) again, X ₄ points are recorded.

Continue to record the subsequent number of times the threshold is reached according to the above process.

7) Start timing from the first record of reaching the threshold. If within the set time range T, when the recorded number of reaching the threshold reaches (greater than or equal to) the set number of times n, a trigger signal is generated to trigger the alarm of the alarm device or Trigger the corresponding actions of other devices. For example, for the process shown in Figure 7 to Figure 10, start timing from X ₁ point, if within the time range T, the number of recorded points (X ₁ , X ₂ , X ₃ ... X _n ) is greater than the set number of times n , To generate a trigger signal to trigger the alarm of the alarm device or trigger the corresponding operation of other devices. Preferably, the duration of 2 seconds ≤ T ≤ 6 seconds, n can be 2, or it can be 3, or it can also be 4. The number of times T and n can be set to eliminate most of the hot air and sunlight The effect of interference.

FIG. 11 shows a logic flow chart when the number of times n is set to 3 in an embodiment of the present application, and the flow includes:

Step a, start sampling, then go to step b or step b';

Step b: Judge whether the interference waveform reaches the first voltage threshold, if yes, go to step c, otherwise return to step a;

Step c, record X ₁ point, then go to step d;

Step d, continue sampling, and enter step e;

Step e: Judge whether the interference waveform reaches the second voltage threshold, if yes, go to step f, otherwise go to step k;

Step f, record X ₂ points, then go to step g;

Step g, continue sampling, and enter step h;

Step h, judge whether the interference waveform reaches the first voltage threshold, if yes, go to step i, otherwise go to step l;

Step i, record X ₃ points, then go to step j;

Step j: Generate a trigger signal and start the next cycle;

Step k: Judge whether the timing time reaches the set time range T, if it is, the loop ends, otherwise it returns to step d;

Step 1. Determine whether the timing time reaches the set time range T, if it is, the loop ends, otherwise it returns to step g;

Step b', judge whether the interference waveform reaches the second voltage threshold, if yes, go to step c', otherwise return to step a;

Step c', record X ₁ point, then go to step d';

Step d', continue sampling, and enter step e';

Step e', judge whether the interference waveform reaches the first voltage threshold, if yes, go to step f', otherwise go to step k';

Step f', record X ₂ points, and then go to step g';

Step g', continue sampling, and enter step h';

Step h', judge whether the interference waveform reaches the second voltage threshold, if yes, go to step i', otherwise go to step l';

Step i', record X ₃ points, then go to step j';

Step j', generate a trigger signal, and start the next cycle;

Step k', judge whether the timing time reaches the set time range T, if yes, the loop ends, otherwise, return to step d';

Step l', judge whether the timing time reaches the set time range T, if yes, the loop ends, otherwise, return to step g'.

The PIR sensor signal triggering method and device according to the embodiments of the application are used to carry out the actual three groups of comparative tests; among them, the duration of T is set to 5 seconds in group A, and the alarm is triggered when n=3; the duration of T is set to 5 seconds in group B , When n=2, the alarm will be triggered; the C group setting will trigger the alarm as long as the X1 point is generated. The three sets of comparative test environments are sunny outdoor environments, the total test duration is 3 days, the PIR sensor is placed in an outdoor open-air environment, and someone passes through the test area within 3 days, and the number of passes recorded 60 times, then the three sets of comparative tests are as follows As shown in the table.

To	A组Group A	B组Group B	C组Group C
报警次数Number of alarms	6060	126126	18221822
误报次数Number of false positives	00	6666	17621762

It can be seen that the optimal embodiment adopts the setting of the duration of T as 5 seconds, and triggering the alarm when n=3 can achieve the optimal effect of avoiding false alarms.

The embodiment of the present application also provides an electronic device for executing the method for triggering a PIR sensor signal. The electronic device includes: at least one processor and a memory. The memory and at least one processor are communicatively connected, for example, the memory and at least one processor are connected through a bus. The memory stores instructions executable by at least one processor, and the instructions are executed by the at least one processor, so that the at least one processor executes the steps in the method for triggering the PIR sensor signal as described above.

The embodiments of the present application also provide a non-volatile computer-readable storage medium. The non-volatile computer-readable storage medium stores instructions. When the instructions are executed by the processor, the processor executes the The PIR sensor signal triggers the steps in the method.

The embodiment of the present application also provides a computer program product containing instructions, which when running on a computer, causes the computer to execute each step in the method for triggering the PIR sensor signal as described above.

The method and device for triggering the PIR sensor signal in the embodiments of the present application utilize the characteristics of different waveforms generated by the human body and hot air on the PIR sensor, and based on the waveform generated by the human body on the PIR sensor, by setting the first voltage threshold and the second voltage threshold. Voltage threshold, within the preset time range when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, the number of times the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold and the second voltage threshold reaches the set When the number of times, a trigger signal is generated, thereby realizing accurate identification of the human body waveform and signal triggering. Among them, the first voltage threshold and the second voltage threshold are when the human body moves within the effective detection range of the PIR sensor, the waveform generated by the subsequent amplification device of the PIR sensor can alternately reach the set number of times within a certain period of time, and heat sources such as hot air within a certain period of time The voltage threshold cannot be reached for the set number of times alternately. Through the setting of this voltage threshold, the recognition of the human body waveform is realized. The method and device for triggering PIR sensor signals in the embodiments of the present application can be applied to the existing bipolar PIR sensor equipment, and there is no need to modify the existing bipolar PIR sensor equipment, and only need to be used in the existing bipolar PIR sensor equipment. The signal output end of the PIR sensor can be connected to the device that realizes the PIR sensor signal trigger method and device function of the embodiment of the present application. It has high compatibility with the existing bipolar PIR sensor equipment and does not need to be used for the existing bipolar PIR Transformation of the sensor equipment saves the investment in the transformation of the existing bipolar PIR sensor equipment.

The above are only the preferred embodiments of this application and are not intended to limit this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in this application Within the scope of protection.

Claims

A PIR sensor signal trigger method, including:

Setting the first voltage threshold and the second voltage threshold;

Within the preset time range from the moment when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold and the second voltage threshold. When the number of voltage threshold reaches the set number of times, a trigger signal is generated.
The PIR sensor signal triggering method according to claim 1, characterized in that:

The PIR sensor is a bipolar PIR sensor.
The PIR sensor signal triggering method according to claim 1, characterized in that:

The monitoring signal generated by the PIR sensor is generated by the PIR sensor and amplified by an operational amplifier circuit electrically connected to the PIR sensor.
The PIR sensor signal triggering method according to claim 1, characterized in that:

The first voltage threshold is greater than the second voltage threshold; or

The first voltage threshold is less than the second voltage threshold.
The PIR sensor signal triggering method according to claim 1, characterized in that:

The duration of the preset time range belongs to a duration range of 2 seconds to 6 seconds.
The PIR sensor signal triggering method according to claim 1, characterized in that:

The set times are 2 times, or 3 times, or up to 4 times.
The method for triggering a PIR sensor signal according to claim 1, wherein the PIR sensor is within a preset time range when the monitoring signal generated by the PIR sensor reaches the first voltage threshold. When the number of times that the monitoring signal generated by the sensor alternately reaches the first voltage threshold and the second voltage threshold reaches a set number of times, a trigger signal is generated, including:

Within the preset time range from when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, whenever it is detected that the monitoring signal generated by the PIR sensor reaches the first voltage threshold, and In the previous count, it was detected that the monitoring signal generated by the PIR sensor reached the second voltage threshold, and the number of times the monitoring signal generated by the PIR sensor reached the threshold was increased by 1, and whenever the PIR was detected The monitoring signal generated by the sensor reaches the second voltage threshold, and in the previous count, it was detected that the monitoring signal generated by the PIR sensor reached the first voltage threshold, and it was recorded that the monitoring signal generated by the PIR sensor reached The number of thresholds is increased by one, and the number of times the monitoring signal generated by the PIR sensor reaches the threshold is the first time when starting to count and record;

When the recorded number of times the monitoring signal generated by the PIR sensor reaches the threshold reaches the set number of times, a trigger signal is generated.
A PIR sensor signal trigger device, including:

A first pyroelectric element and a second pyroelectric element, the first pyroelectric element and the second pyroelectric element are connected with the same polarity;

A MOS tube, the gate G of the MOS tube is connected to the negative electrode of one of the two pyroelectric elements, and the drain of the MOS tube is connected to the power supply voltage;

Operational amplifier, the input terminal of the operational amplifier is connected to the source S of the MOS tube, and the output terminal of the operational amplifier outputs the monitoring signal of the PIR sensor;

Processor, used to execute:

Obtaining a preset first voltage threshold and a second voltage threshold, where the first voltage threshold and the second voltage threshold are used to indicate that the PIR sensor detects a human body;

Acquiring the monitoring signal of the PIR sensor output by the operational amplifier;

Within the preset time range from the moment when the monitoring signal generated by the PIR sensor reaches the first voltage threshold, the monitoring signal generated by the PIR sensor alternately reaches the first voltage threshold and the second voltage threshold. When the number of voltage threshold reaches the set number of times, a trigger signal is generated.