False-alarm-proof vibration detection device

Abstract

The utility model is suitable for the field of vibration detection, provides a kind of anti misjudgment vibration detection device, including vibration detection module, sound detection module, main control module, alarm module and shell;The vibration detection module adopts magnetic displacement sensor, for detecting vibration mechanical wave and conversion into electric signal;The sound detection module adopts directional electret microphone, for picking up the sound wave signal generated by impact and conversion into electric signal;The vibration detection module and sound detection module are respectively connected with special amplification circuit, and electric signal is amplified to the detectable range of main control module;In the utility model, through the double signal fusion mode of vibration detection and sound detection combination, the accurate processing of signal in combination with special amplification circuit, utilize directional microphone to filter non-front sound interference and adjustable reference value to filter slight vibration interference, can effectively distinguish real vibration and interference signal, greatly reduce the probability of misjudgment, ensure that detection result is reliable.

Description

Technical Field

[0001] This utility model belongs to the field of vibration detection, and in particular relates to a vibration detection device to prevent false judgment. Background Technology

[0002] In industrial production, security, transportation, and other fields, vibration detection technology is an important means of equipment fault monitoring, safety precautions, and cargo protection. However, existing vibration detection technologies have significant drawbacks:

[0003] Weak anti-interference ability: It is sensitive to environmental noise, slight vibration and other interference, and is easily misjudged (such as the vibration of doors and windows caused by wind or the vibration transmitted by a vehicle being misjudged as illegal intrusion).

[0004] The signal processing is too simplistic: it judges vibration solely based on the presence or absence of a signal, without considering key factors such as duration and intensity changes, which leads to normal equipment vibrations and vehicle bumps being misjudged as abnormal.

[0005] Poor environmental adaptability: Lacking an effective protective structure, the circuit is easily interfered with in complex environments such as high temperature and humidity, resulting in unstable detection performance;

[0006] Furthermore, although traditional vibration sensors (inertial mechanical contact type, piezoelectric type, and resistance strain type) each have their own characteristics, they generally suffer from problems such as difficulty in vibration quantification, poor consistency, limited lifespan, or high cost. In demanding scenarios, they are prone to false triggering or failure to trigger.

[0007] Therefore, a vibration detection device that prevents misjudgment is needed to solve the above problems. Utility Model Content

[0008] The purpose of this utility model embodiment is to provide a vibration detection device to prevent misjudgment, so as to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, this utility model provides the following technical solution:

[0010] A vibration detection device for preventing false alarms includes a vibration detection module, a sound detection module, a main control module, an alarm module, and a housing;

[0011] The vibration detection module uses a magnetic displacement sensor to detect vibration mechanical waves and convert them into electrical signals;

[0012] The sound detection module uses a directional electret microphone to pick up the sound wave signal generated by the impact and convert it into an electrical signal;

[0013] The vibration detection module and the sound detection module are each connected to a dedicated amplification circuit to amplify the electrical signal to the range that the main control module can detect.

[0014] The main control module is connected to the vibration detection module and the sound detection module respectively. It is used to receive two amplified electrical signals, perform analog-to-digital conversion and quantization, compare them with preset reference values, and generate effective vibration signals.

[0015] The alarm module is connected to the main control module, and the main control module controls the alarm module to issue an alarm after generating a valid vibration signal;

[0016] The vibration detection module, sound detection module, main control module, and alarm module are all located inside the outer casing.

[0017] In a further technical solution, the amplification circuit connected to the magnetic displacement sensor includes an operational amplifier LMV721 and a comparator LM393A, forming an inverted amplification preamplifier circuit. The induced electromotive force generated by the physical displacement of the magnetic displacement sensor is amplified by this circuit after being low-pass filtered, with an amplification factor of ≈50 times and a frequency response range of 20Hz~20kHz.

[0018] A further technical solution is that the amplifier circuit connected to the directional electret microphone includes an operational amplifier OPA320 and a comparator LM393A, forming a non-inverting preamplifier circuit with good amplitude stability, operating on a single 3.3V power supply, amplification factor of ≈13 times, and a frequency response range of 20Hz~20kHz; the directional electret microphone has a cardioid polar pattern and only receives sound signals directly in front.

[0019] A further technical solution is that the magnetic displacement sensor has a sensitivity of (20±5℃)~10mv / g, a frequency response of (±5%)10-100Hz, and a linearity of ±4mV / g; the directional electret microphone has a sensitivity of -45dB and a microphone impedance of 2.2kΩ.

[0020] In a further technical solution, the main control module is a microprocessor STM32F405RG. The microprocessor has a signal input interface, including a PA1 pin (MIC_DET1) and a PA2 pin (SJ_DET2), which respectively receive the microphone amplified signal and the magnetic displacement sensor amplified signal, and compare them with the preset reference value after quantization through analog-to-digital conversion.

[0021] A further technical solution is that the main control module performs a data acquisition action with a cycle of 50ms, and the acquisition frequency is once every 1ms. The microphone channel and magnetic displacement channel are used for cross-acquisition. The acquired data is compared with the pre-recorded template data. If the data meets the requirements, the high and low level indicator detection results are output through the GPIO port.

[0022] In a further technical solution, the alarm module includes an indicator light and / or a buzzer. The indicator light is electrically connected to the PC9 pin of the microprocessor. After the main control module generates an effective vibration signal, it controls the alarm module to issue an alarm.

[0023] A further technical solution is that the housing is provided with an installation structure for connecting to the monitored object, the housing is rigidly connected to the sensor, and the microphone is installed through a directional hole; the housing is made of a shock-absorbing material to reduce environmental interference.

[0024] Compared with the prior art, the beneficial effects of this utility model are:

[0025] This invention significantly improves detection accuracy: by combining vibration detection and sound detection in a dual-signal fusion mode, and using a dedicated amplification circuit for precise signal processing, it utilizes a directional microphone to filter out non-frontal sound interference and an adjustable reference value to filter out slight vibration interference. This effectively distinguishes between real vibrations (such as frontal impacts and impacts from hard objects) and interference signals (such as wind, insect impacts, and side collisions), greatly reducing the probability of misjudgment and ensuring reliable detection results.

[0026] This invention enhances operational stability: the main control module uses a stable STM32F405RG microprocessor, each module has a reasonable circuit design, and signal transmission is stable; the outer shell is made of shock-absorbing material, which provides good protection for the internal modules and reduces the impact of environmental factors such as high temperature, humidity, and bumps on the detection performance, so that the device can still work stably in complex environments.

[0027] This utility model features adjustable sensitivity and ease of use: the sound intensity reference value and mechanical wave reference value can be manually adjusted according to the usage environment to adapt to different scenario requirements; the installation structure set on the shell is compatible with a variety of monitored objects, the installation process is simple and convenient, lowers the threshold for use, and is suitable for users with different technical levels;

[0028] This utility model has strong scalability: the alarm module supports multiple alarm modes such as indicator lights and buzzers, which users can flexibly choose according to their actual needs; the main control module has reserved peripheral interfaces, which can be easily connected to peripherals such as wireless communication modules to realize extended functions such as remote alarm and meet diverse usage needs;

[0029] This utility model has a wide range of applications: by adjusting the reference value parameters, the device can be adapted to various scenarios such as anti-tampering of power distribution boxes, impact detection of basketball backboard rims, monitoring of the operating status of industrial equipment, and monitoring of home security doors and windows. It has strong versatility, and its price is close to that of resistance strain gauge sensors, while its consistency is close to that of piezoelectric sensors.

[0030] To more clearly illustrate the structural features and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the detection device of this utility model;

[0032] Figure 2 This is a system flowchart of the present invention;

[0033] Figure 3 This is the circuit diagram of the microcontroller of this utility model;

[0034] Figure 4 This is the circuit diagram of the microphone sensor of this utility model;

[0035] Figure 5 This is the circuit diagram of the magnetic displacement sensor of this utility model. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0037] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0038] Example 1 (Distribution box anti-tampering scenario)

[0039] like Figures 1-5 As shown, this utility model embodiment provides a vibration detection device to prevent false alarms, including a vibration detection module, a sound detection module, a main control module, an alarm module, and a housing. The vibration detection module uses a magnetic displacement sensor and is connected to an amplification circuit composed of an operational amplifier LMV721 and a comparator LM393A; the sound detection module uses a directional electret microphone and is connected to an amplification circuit composed of an operational amplifier OPA320 and a comparator LM393A; the main control module is an STM32F405RG microprocessor, which receives the amplified signal from the microphone through the PA1 pin (MIC_DET1) and receives the amplified signal from the magnetic displacement sensor through the PA2 pin (SJ_DET2); the alarm module includes a buzzer connected to the corresponding pin of the microprocessor; the housing is made of metal and is rigidly connected to the power distribution box, and the microphone is mounted on the front of the housing through directional holes, with the mounting structure being bolt-fixed.

[0040] In this embodiment, the template design and strategy are as follows: the microphone channel signal strength is activated when it is greater than 80dB, and the magnetic displacement channel is activated when the drop height is greater than 7cm. An alarm signal is issued when both channels meet the conditions simultaneously. When someone deliberately opens the box from the front or hits the distribution box from the front, the vibration mechanical wave is transmitted to the magnetic displacement sensor to generate a sine wave signal. After amplification, the signal is input to the microprocessor. At the same time, the directional microphone picks up the impact sound wave signal, amplifies it, and inputs it to the microprocessor. When both signals reach the reference value, the microprocessor controls the buzzer to sound an alarm. When a car horn is directed at the microphone, only the microphone channel is activated, and the magnetic displacement channel is not activated, so the acquisition result is ignored. When a small animal climbs from the side, only the magnetic displacement channel is activated, and the sound channel is not activated, so no alarm is triggered. When there is natural wind, neither channel is activated, so no alarm is triggered. This device effectively avoids false alarms caused by environmental interference, demonstrating high detection accuracy and good anti-interference performance.

[0041] Example 2 (Basketball backboard impact detection scenario)

[0042] The difference between this embodiment and embodiment 1 is that the template design and strategy activate the microphone channel when the signal strength is greater than 60dB, activate the magnetic displacement channel when the drop height is greater than 6cm, and determine the impact of a hard object and trigger an alarm when a high-frequency impact signal is detected within 50ms; the outer shell is made of plastic and is fixed to the basketball backboard frame by a snap-fit ​​structure; the alarm module includes an indicator light and is connected to the PC9 pin of the microprocessor.

[0043] In this embodiment, when impacted by a rubber basketball, due to the shock-absorbing properties of rubber, the output signal strength of the sound channel and magnetic displacement channel is relatively low and the duration is relatively long (greater than 20ms but less than 40ms), so the microprocessor determines that it is safe and does not alarm. When impacted by a metal or hard object such as a stone, the two channels are activated and an impact pulse is detected within 10ms, so the microprocessor controls the indicator light to light up and alarm. When the basketball is moved by wind in a natural environment, the magnetic displacement channel may be activated but the sound channel is not activated. If no impact pulse is detected within 50ms, no action is taken. This device can accurately distinguish the type of impact object, effectively protect the basketball backboard frame, and demonstrates the effect of adjustable sensitivity and strong scene adaptability.

[0044] The working principle and usage process of this invention: After the anti-false alarm vibration detection device is fixed to the monitored object through the mounting structure of the outer shell, the device begins to enter the working state.

[0045] When the monitored object is subjected to a frontal impact, the vibration mechanical wave is first transmitted to the magnetic displacement sensor. Due to inertia, the sensor reciprocates and cuts the magnetic field lines, generating a weak oscillating sine wave signal. This signal is sent to an amplification circuit composed of an operational amplifier LMV721 and a comparator LM393A, which amplifies it to a voltage signal within the range of 0-3V.

[0046] The sound signal is then transmitted to the directional electret microphone, which picks up the sound wave signal generated by the impact and sends it to the amplification circuit composed of operational amplifier OPA320 and comparator LM393A to amplify it to a voltage signal in the range of 0-3V.

[0047] In the audio signal channel, the MCU processor outputs a fixed voltage audio signal reference value through a D / A converter. The signal collected by the microphone is amplified and then sent to a comparator amplifier circuit. If the output value is lower than the reference value, it is filtered out; if it is higher than the reference value, it is output to the A / D acquisition terminal of the microcontroller. The magnetic displacement sensor channel is processed in the same way.

[0048] When the MCU receives a valid signal, it performs a data acquisition operation with a cycle of 50ms and a acquisition frequency of once every 1ms, with the microphone channel and magnetic displacement channel acquiring data alternately. After the acquisition is completed, the data is analyzed and compared with the pre-recorded template data. If the data meets the requirements, the high and low level indicators are output through the GPIO port to detect the detection results, and the indicator light of the alarm module is turned on and / or the buzzer sounds. For devices with an extended wireless communication module, alarm information can also be sent to the user's handheld terminal.

[0049] Through the above workflow, the device achieves accurate detection and judgment of vibration, effectively avoiding misjudgments caused by interference signals, and providing a reliable solution for vibration monitoring in different scenarios.

[0050] The circuits, electronic components, and modules involved are all existing technologies, which can be fully implemented by those skilled in the art, and need not be elaborated upon. The content protected by this utility model does not involve any improvement to the software and methods.

[0051] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A vibration detection device to prevent false alarms, characterized in that, It includes a vibration detection module, a sound detection module, a main control module, an alarm module, and a housing; The vibration detection module uses a magnetic displacement sensor to detect vibration mechanical waves and convert them into electrical signals; The sound detection module uses a directional electret microphone to pick up the sound wave signal generated by the impact and convert it into an electrical signal; The vibration detection module and the sound detection module are each connected to a dedicated amplification circuit to amplify the electrical signal to the range that the main control module can detect. The main control module is connected to the vibration detection module and the sound detection module respectively. It is used to receive two amplified electrical signals, perform analog-to-digital conversion and quantization, compare them with preset reference values, and generate effective vibration signals. The alarm module is connected to the main control module, and the main control module controls the alarm module to issue an alarm after generating a valid vibration signal; The vibration detection module, sound detection module, main control module, and alarm module are all located inside the outer casing.

2. The vibration detection device for preventing false judgment according to claim 1, characterized in that, The magnetic displacement sensor is connected to an amplifier circuit including an operational amplifier LMV721 and a comparator LM393A, which together form an inverting amplifier preamplifier circuit with an amplification factor of approximately 50 times and a frequency response range of 20Hz to 20kHz.

3. The vibration detection device for preventing false judgment according to claim 1, characterized in that, The amplifier circuit connected to the directional electret microphone includes an operational amplifier OPA320 and a comparator LM393A, forming a non-inverting preamplifier circuit with a gain of approximately 13 times and a frequency response range of 20Hz to 20kHz; the directional electret microphone has a cardioid polar pattern.

4. The vibration detection device for preventing false judgment according to claim 1, characterized in that, The magnetic displacement sensor has a sensitivity of (20±5℃) ~10mv / g, a frequency response of (±5%) 10-100Hz, and a linearity of ±4mV / g; the directional electret microphone has a sensitivity of -45dB and a microphone impedance of 2.2kΩ.

5. The vibration detection device for preventing false judgment according to claim 1, characterized in that, The main control module is an STM32F405RG microprocessor. The microprocessor has a signal input interface, including a PA1 pin (MIC_DET1) and a PA2 pin (SJ_DET2), which receive the microphone amplification signal and the magnetic displacement sensor amplification signal, respectively.

6. The vibration detection device for preventing false judgment according to claim 1, characterized in that, The main control module performs a data acquisition action with a cycle of 50ms and a acquisition frequency of once every 1ms. The microphone channel and magnetic displacement channel are used for cross-acquisition. The acquired data is compared with the pre-recorded template data. If the data meets the requirements, the high and low level indicators are output through the GPIO port to detect the results.

7. The vibration detection device for preventing false judgment according to claim 1, characterized in that, The alarm module includes an indicator light and / or a buzzer, the indicator light being electrically connected to the PC9 pin of the microprocessor.

8. The vibration detection device for preventing false judgment according to claim 1, characterized in that, The housing is provided with an installation structure for connecting to the monitored object. The housing is rigidly connected to the sensor, and the microphone is installed through a directional hole. The housing is made of a material with shock-absorbing function.

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