KR102998552B1 - Intelligent Portable Earthquake Detector Using 3-Axis XYZ Acceleration Sensor - Google Patents

Abstract

The present invention provides a portable earthquake detection device comprising a main body case, an earthquake detection board disposed in the lower part of the internal space of the main body case and equipped with a 3-axis (X, Y, Z) acceleration sensor and a microcontroller unit (MCU), a power connection unit, a communication unit, and an alarm module. The device collects vibration data using the 3-axis (X, Y, Z) acceleration sensor, and the microcontroller unit (MCU) sets an initial reference point and determines whether an earthquake has occurred by accumulating weights according to vibration intensity. It can maintain stable detection performance over a long period through an automatic reset of the reference point and a filtering algorithm, and provides an earthquake alarm to the user in real time through an LED and a speaker included in the alarm module. The present invention provides a practical earthquake detection device that simultaneously possesses portability, real-time responsiveness, and high reliability through an automatic correction function.

Description

Intelligent Portable Earthquake Detector Using 3-Axis XYZ Acceleration Sensor

The present invention relates to a portable earthquake detection device that detects vibrations during an earthquake and provides an alarm. More specifically, it relates to a portable earthquake detection device that detects seismic waves (P-waves, S-waves, etc.) in real time using a 3-axis (X, Y, Z) acceleration sensor and includes an intelligent signal processing algorithm and a periodic reference point reset function to realize more accurate and reliable earthquake detection.

Most existing earthquake detection systems are designed as fixed units, which imposes constraints on site selection, securing infrastructure, and power connections during installation, resulting in high installation and maintenance costs. Furthermore, because these fixed systems are stationary in specific locations, they are not portable; additionally, delays in alert delivery may occur depending on the physical distance from the user, and users may be excluded from earthquake warnings while on the move.

For example, registered patent No. 10-1546074 (Patent Document 1) discloses a system for detecting and diagnosing earthquakes in structures by collecting multi-axis data using a 3-axis acceleration sensor unit, but the said patent technology is based on application within a fixed structure and has limitations in terms of portability.

Furthermore, existing earthquake detection devices had a problem in that their effectiveness as early warning systems was limited due to the low effectiveness of early response, as they lacked or were absent the function to clearly distinguish between P-waves (Primary waves), which are weak vibrations occurring in the initial stages of an earthquake, and S-waves (Secondary waves), which are strong vibrations arriving later, in order to effectively provide warnings to users.

For example, registered patent No. 10-2772882 (Patent Document 2) discloses a technology that enables relatively precise vibration measurement using a vibration detection device based on a 3-axis acceleration sensor that detects acceleration in the X, Y, and Z axes, but does not include explicit technology for vibration waveform analysis (distinguishing between P-waves and S-waves).

In addition, in the case of existing earthquake detection devices equipped with acceleration sensors, there was a problem in that the reference point of the acceleration sensor was set manually or changed during long-term use, resulting in false detection or reduced sensitivity.

For example, registered patent No. 10-2793636 (Patent Document 3) presents a technology that analyzes acceleration values to provide an alarm system based on specific conditions, but there are limitations in preventing false positives through real-time automatic reference point correction and multi-filtering algorithms.

Therefore, there is a growing need for an earthquake detection device that can ensure user portability while detecting earthquakes with high accuracy by distinguishing between P-waves and S-waves in real time, and also reduce false positive rates through automatic reference point setting and resetting and multi-filtering.

[Patent Document 1] Republic of Korea Registered Patent Publication No. 10-1546074 [Patent Document 2] Republic of Korea Registered Patent Publication No. 10-2772882 [Patent Document 3] Republic of Korea Registered Patent Publication No. 10-2793636

The present invention has been devised to solve the problems of the aforementioned prior art, and aims to provide a portable earthquake detection device that helps a user respond quickly and accurately when an earthquake occurs.

In other words, the present invention aims to overcome the limitations of existing technology by implementing an earthquake detection device that is portable, can be used regardless of installation direction or location, reduces the false positive rate to improve the accuracy of earthquake detection and alarms, and provides an intuitive warning means to the user.

The portable earthquake detection device of the present invention for achieving the above objectives can collect and analyze external vibration data in real time using a 3-axis (X, Y, Z) acceleration sensor, maintain long-term accuracy through automatic reference point setting and periodic initialization, and provide visual and auditory alarms.

In the present invention, a portable earthquake detection device for detecting an earthquake and providing an alarm to a user is,

The main body case and,

An earthquake detection board disposed in the internal space of the main body case and comprising a 3-axis (X, Y, Z) acceleration sensor and a microcontroller unit (MCU), and

It includes an alarm module positioned on top of the above earthquake board, and

The above 3-axis acceleration sensor is configured to collect vibration data generated from the external environment, and

The microcontroller unit analyzes data collected from the 3-axis accelerometer,

- When power is first supplied, set the origin using the current acceleration value as the reference point, and

- Calculate the amount of change in acceleration of each axis using the difference from the above reference point, and

- Calculate vibration intensity when the change in acceleration of each axis exceeds a preset threshold, and

- Accumulate the cumulative count by assigning weights according to the above vibration intensity,

- Control to provide an earthquake alarm through an alarm module when the above accumulated count exceeds a predetermined threshold value, and

- After a predetermined time has elapsed following the completion of earthquake detection, the reference point of the acceleration sensor is configured to be reset for additional earthquake detection, and

The above alarm module may include an LED and a speaker to provide visual and auditory alarms to the user.

In the portable earthquake detection device of the present invention, the MCU is,

Automatically resets the reference point at regular intervals, and

Even if the accumulated count remains below the alarm threshold, the reference point is reset, and

It may further include a function to reset the reference point even after a predetermined time has elapsed following an earthquake detection alarm.

In the portable earthquake detection device of the present invention, the MCU can perform the function of refining the vibration signal and reducing the false positive rate by applying at least one filtering algorithm among a Kalman filter for removing noise of non-seismic vibrations occurring in daily life or disturbances included in data collected from an acceleration sensor and a moving average filter for removing noise of non-seismic vibrations occurring in daily life.

In the portable sensing device of the present invention, a sound volume amplification resonance tube may be further included on the upper part of the speaker inside the main body case, and a USB terminal may be further provided on one side of the main body case.

The portable earthquake detection device according to the present invention provides the following effects.

First, the miniaturization and portability of the device enable direct earthquake detection around the user in various environments, including indoors and outdoors, thereby overcoming the limitations of existing fixed earthquake detection systems.

Second, through multi-axis detection and automatic zero setting functions based on a 3-axis accelerometer, the same detection accuracy can be secured regardless of the installation direction or location.

Third, the earthquake detection algorithm uses a method of quantifying vibration intensity and accumulating weights to recognize the difference between P-waves and S-waves, and by accurately providing alerts accordingly, it helps users respond early in the initial stages of an earthquake.

Fourth, detection accuracy is maintained even during long-term use through automatic reference point initialization and periodic reset functions, and the possibility of false positives is significantly reduced through the application of noise removal algorithms such as moving average filters and Kalman filters.

Fifth, the intuitive alarm system using LEDs and speakers can effectively convey information in various user environments, and the acoustic amplification design utilizing resonance tubes improves the alarm's reach, enabling a rapid response in emergency situations.

Sixth, the power supply function via the USB port increases ease of use, further enhancing the device's versatility and practicality.

In conclusion, the portable earthquake detection device of the present invention not only ensures earthquake detection accuracy capable of distinguishing and detecting only earthquakes even amidst various forms of environmental vibration, but also provides a comprehensive solution that offers improvements in terms of fieldability, real-time capability, alarm efficiency, and continuous usability—qualities that are difficult to expect from conventional fixed earthquake detection devices. Furthermore, since the user can easily install or carry the device, it offers excellent practicality, and because consistent performance can be expected regardless of the installation direction, it is highly advantageous for widespread use.

FIGS. 1 and FIGS. 2 are perspective views of a portable earthquake detection device according to one embodiment of the present invention.
FIG. 3 is a cross-sectional view of a portable earthquake detection device according to one embodiment of the present invention.
Figure 4 is a detailed plan view of the earthquake detection board and USB terminal of the portable earthquake detection device of Figure 3.

The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various different forms. The embodiments of the present invention are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

Hereinafter, a portable earthquake detection device according to the present invention will be described in detail with reference to the attached drawings.

The portable earthquake detection device (1) of the present invention is a device for detecting an earthquake and providing an alarm to a user, and may include a main body case (10), an earthquake detection board (20) disposed in the internal space of the main body case and including a 3-axis (X, Y, Z) acceleration sensor (21) and a microcontroller unit (MCU; 22), and an alarm module (30) disposed on the upper part of the earthquake detection board (20).

In the present invention, the main body case (10) is not subject to any particular restrictions on its shape and may be of any shape that is easy for a user to carry while being able to house or be equipped with the earthquake detection board (20) and the alarm module (30). An exemplary shape of the main body case (10) of the portable earthquake detection device (1) of the present invention is illustrated in FIGS. 1 and FIGS. 2.

In the present invention, the earthquake detection board (20) is placed in the internal space of the main body case (10), preferably, as shown in FIG. 3, it may be supported so as to detect vibrations transmitted from the outside by being placed horizontally in the lower part of the internal space of the main body case (10). As shown in FIG. 4, the earthquake detection board (20) may include a 3-axis acceleration sensor (21) and a microcontroller unit (22), and may optionally further include a power supply unit (40) and a communication unit (50).

The above 3-axis acceleration sensor (21) is configured to collect vibration data generated from the external environment, and is a sensor that precisely detects vibrations generated from the external environment in three directions (X, Y, Z directions). When an earthquake occurs, a fine tremor (P-wave) of the ground arrives first, followed by a larger vibration (S-wave). The above 3-axis acceleration sensor has a sensitivity sufficient to detect the difference between these two waveforms, which enables rapid early warning. Additionally, since vibrations from a typical earthquake spread in all directions, more accurate earthquake detection becomes possible by integrating and analyzing data from three axes rather than a single axis. The above 3-axis acceleration sensor (21) is capable of sampling hundreds of times per second and can capture even minute vibration changes. It collects vibration data regardless of the orientation in which it is placed (vertical, horizontal, inclined, etc.), and this is corrected through the initial reference point setting. When external vibration occurs, the above 3-axis acceleration sensor measures the acceleration value for each axis in real time and transmits it to the microcontroller unit (MCU; 22).

In the present invention, the MCU (22) is a central control unit of the earthquake detection device and performs a series of processes to determine whether there is an earthquake by analyzing data received from the 3-axis acceleration sensor (21) and to deliver an alarm to the user.

According to one embodiment of the present invention, the MCU (22) analyzes data collected from the 3-axis acceleration sensor (21),

- When power is first supplied, set the origin using the current acceleration value as the reference point, and

- Calculate the amount of change in acceleration of each axis using the difference from the above reference point, and

- Calculate vibration intensity when the change in acceleration of each axis exceeds a preset threshold, and

- Accumulate the cumulative count by assigning weights according to the above vibration intensity,

- Control to provide an earthquake warning through the alarm module (30) when the above accumulated count exceeds a predetermined threshold value, and

- After a predetermined amount of time has elapsed since the earthquake detection is completed, the reference point of the 3-axis acceleration sensor (21) may be configured to be reset for additional earthquake detection.

When power is supplied to the earthquake detection device (1) of the present invention, the MCU (22) automatically sets the current state (initial state) of the 3-axis acceleration sensor (21) at the time when power is first applied as a reference point (zero point), regardless of the installation direction or location, and this reference point serves as a standard for determining the relative magnitude of vibrations to be measured in the future. This reference point setting function is designed so as not to be affected by the installation direction, tilt, or location of the earthquake detection device (1), and serves to eliminate basic environmental data that may vary depending on the installation direction or location of the device, and enables accurate vibration detection by setting the reference point normally even when the device is in an irregular state that is not horizontal or vertical.

After the reference point is set as described above, the 3-axis acceleration sensor (21) measures vibration data collected from the external environment and transmits acceleration values for each of the three axes X, Y, and Z to the MCU (22). The MCU (22) calculates the difference between the current acceleration value of each axis received and the initial reference point to calculate the amount of acceleration change (vibration intensity) for each axis, and calculates the total vibration intensity by summing the amounts of acceleration change for each axis. The MCU (22) compares the measured amount of acceleration change with a pre-set threshold value, and if it exceeds the threshold value, determines it to be an earthquake, assigns a weight according to the vibration intensity, and accumulates it. When the accumulated weight exceeds a predetermined value, it activates the alarm module (30) to notify the user of the occurrence of an earthquake. That is, the MCU (22) assigns a weight when the vibration intensity exceeds a certain level, and the assigned weight is continuously added to the threshold_exceed_count. When this accumulated value exceeds a predetermined value, the MCU (22) determines this as an actual earthquake situation and activates the alarm module, thereby preventing false detection due to temporary vibration or noise and enabling precise detection that responds only to actual earthquakes.

An example of the operation of the MCU (22) according to the present invention is as follows.

The initial reference point (zero point) for each axis,

'zero_xg = 0.1', 'zero_yg = 0.1', 'zero_zg = 0.1' and,

The current average acceleration value for each axis is,

'xg_avg = 0.6', 'yg_avg = 0.4', 'zg_avg = 0.3' and,

Assuming the preset threshold is '0.02',

The MCU (22) performs the following step-by-step operations:

1. Calculation of the difference from the reference point:

- 'abs(0.6 - 0.1) = 0.5' (x-axis)

- 'abs(0.4 - 0.1) = 0.3' (y-axis)

- 'abs(0.3 - 0.1) = 0.2' (z-axis)

2. Determine whether threshold is exceeded:

- x-axis: '0.5 > 0.02' → exceed

- Y-axis: '0.3 > 0.02' → Exceeds

- Z-axis: '0.2 > 0.02' → Exceeds

3. Strength Calculation:

Intensity = abs(0.5) + abs(0.3) + abs(0.2) = 1.0

4. Determining Weights:

- Meets condition 'Intensity > 1.0' → Weight: 10

5. Assign weights and calculate cumulative counts:

Accumulated Count = 10 + .... ,

6. Alarm Module Operation

When the accumulated count reaches 50 or more, activate the alarm module to output an alarm for 60 seconds.

In addition, in the present invention, the MCU (22) can periodically reset the reference point at regular intervals even when the accumulated earthquake detection value has not reached a threshold value so that the reference point is not distorted due to long-term use, or automatically reset the reference point after a certain period of time has elapsed following an earthquake detection warning, thereby completing preparation for the next earthquake detection. That is, preferably, the MCU (22) has the function of automatically resetting the reference point at regular intervals, resetting the reference point even when the accumulated count is maintained below the alarm threshold, and resetting the reference point even after a predetermined period of time has elapsed following the occurrence of an earthquake detection alarm. In this way, it is possible to flexibly respond to changes in the user's installation method or location through automatic zero point setting and reference point correction independent of direction upon initial power application, and even during long-term use, continuous sensitivity can be maintained by correcting data deviations over time through reference point resetting, thereby ensuring long-term accuracy and reliability.

In one embodiment of the present invention, the MCU (22) can perform the function of refining vibration signals and reducing false positive rates by applying at least one filtering algorithm among a Kalman filter and a moving average filter for removing sensor noise, in order to increase detection reliability and selectively detect only actual earthquake vibrations. Preferably, the MCU (22) applies a multi-(composite) filtering algorithm of a Kalman filter and a moving average filter. The Kalman filter helps to analyze vibration patterns more precisely by improving the accuracy of measurement data that changes over time by filtering noise from disturbances or non-seismic vibrations occurring in daily life included in data collected from an acceleration sensor and removing noise of continuous and gradual patterns. The moving average filter can increase detection reliability by removing temporary and sudden spikes by filtering noise of temporary vibrations in daily life.

In the present invention, the alarm module (30) is an output device that intuitively conveys earthquake detection results to a user and may include at least one alarm means among a visual alarm means and an auditory alarm means. Preferably, the alarm module (30) may include a dual alarm means for a visual alarm and an auditory alarm. For example, as shown in FIG. 3, the alarm module (30) is placed on the upper part of the earthquake detection board (20) inside the main body case (10), and as shown in FIG. 4, it may include an LED (31) for a visual alarm and a speaker (32) for an auditory alarm.

In a preferred embodiment of the present invention, the LED (31) may be configured to operate differently in color, blinking speed, or period depending on the intensity of the vibration or the type of seismic wave (P-wave, S-wave, etc.). For example, an earthquake warning may be implemented such that an orange LED lights up slowly for weak vibrations (P-waves) and an LED of the same color flashes rapidly for strong vibrations (S-waves). The speaker (32) immediately notifies the user or the surroundings of the earthquake situation through a warning sound, and may output different warning sounds of different frequencies or volumes depending on the detected vibration intensity, thereby allowing the user to intuitively recognize whether an earthquake has occurred and its intensity by sound alone. The warning sound of the speaker (32) may last for a certain period of time, for example, about 60 seconds, and the warning sound output time can be set as needed.

The above-described complex alarm system enables effective warning delivery in various environments, including for users with hearing or visual impairments.

In addition, in a preferred embodiment of the present invention, a resonance tube (33) connected to the speaker (32) may be placed inside the main body case (10) as shown in FIG. 3 to spread and amplify the warning sound when an earthquake occurs. The resonance tube (33) amplifies the volume of the speaker (32), thereby enabling the warning sound to be transmitted over a wider range without power consumption, and contributes to increasing the clarity of the warning and the user's awareness rate so that the user can clearly perceive the warning sound even outdoors or in noisy environments.

In one embodiment of the present invention, the portable sensing device (1) may be provided with a USB terminal (60) on one side of the main body case (10), as shown in FIGS. 1 to 4, in order to provide a communication function along with ease of power connection. When the USB terminal (60) is provided, it can be connected to an external power source to receive power from the outside, or connected to a universal charger or auxiliary battery, thereby enabling easy charging and power supply in various environments such as buildings, vehicles, and personal portable devices. In addition, data communication (e.g., storing detection logs, changing setting values, etc.) is possible through the USB terminal (60), making it applicable to various application environments.

The portable earthquake detection device of the present invention, as described above, provides a practical alarm system to the user by simultaneously securing portability and accurate earthquake detection capabilities. It effectively overcomes the problems associated with existing fixed earthquake detection systems, such as installation constraints, high costs, and limited usage environments, and is a useful earthquake detection device that can be easily used by general users based on its compact and lightweight structure and low-power design.

1 .... Portable earthquake detection device
10 .... Main body case
20 .... earthquake detection board
21 .... 3-axis accelerometer
22 .... Microcontroller Unit (MCU)
30 .... Alarm Module
31 .... LED
32 .... speakers
33 .... Resonance tube
40 .... Power supply
50 .... Communications Department
60 .... USB port

Claims (4)

The main body case and,
An earthquake detection board disposed in the internal space of the main body case and comprising a 3-axis (X, Y, Z) acceleration sensor and a microcontroller unit (MCU), and
A portable earthquake detection device comprising an alarm module positioned on the upper part of the earthquake detection board within the internal space of the main body case,
The above 3-axis acceleration sensor is configured to collect vibration data generated from the external environment, and
The microcontroller unit analyzes data collected from the 3-axis accelerometer,
- When power is first supplied, set the origin using the current acceleration value as the reference point, and
- Calculate the amount of change in acceleration of each axis using the difference from the above reference point, and
- If the change in acceleration of each axis exceeds a preset threshold, the change in acceleration of each axis is summed to calculate the vibration intensity, and
- Accumulate the cumulative count by assigning weights according to the above vibration intensity,
- Control to provide an earthquake alarm through an alarm module when the above accumulated count exceeds a predetermined threshold value, and
The above microcontroller unit is,
Automatically resets the reference point at regular intervals, and
Even if the accumulated count remains below the alarm threshold, the reference point is reset, and
It is configured to reset the reference point for additional earthquake detection even after a predetermined time has elapsed following an earthquake detection warning, and
The above alarm module is a portable earthquake detection device comprising an LED and a speaker to provide visual and auditory alarms to the user. In paragraph 1,
A portable earthquake detection device in which the above LED is configured to operate with different colors or blinking cycles depending on the vibration intensity, and the above speaker is configured to output different warning sounds of different frequencies or volumes depending on the vibration intensity. In paragraph 1 or 2,
A portable earthquake detection device that performs the function of refining vibration signals and reducing false positive rates by applying at least one filtering algorithm, such as a Kalman filter for removing noise from disturbances or non-seismic vibrations occurring in daily life included in data collected from an acceleration sensor and a moving average filter for removing noise from non-seismic vibrations occurring in daily life. In paragraph 1 or 2,
A portable earthquake detection device comprising, inside the main body case, a resonance tube for volume amplification on the upper part of the speaker, and a USB terminal provided on one side of the main body case.