Method for alarming by knocking safety helmet

Abstract

The invention relates to a method for giving an alarm by knocking a safety helmet, which specifically comprises the following steps that: a positioner is arranged in the safety helmet, a positioning circuit of the positioner comprises an acceleration sensor, and when the safety helmet is knocked, a central processing unit in the positioning circuit receives a signal of the acceleration sensor and judges whether to give an alarm or not; the method comprises the following steps: 1, setting the number of knocking times as 0; 2, judging whether the safety helmet is worn correctly, if so, turning to 3, and otherwise, turning to 2; 3, judging whether the knocking force and the duration meet set requirements or not; if so, adding 1 to the number of knocking times, and turning to 4, otherwise, turning to 2; 4, if the knocking frequency reaches the set frequency, turning to 6, otherwise, turning to 5; 5, judging whether the knocking interval meets a set requirement or not; if so, turning to 2, otherwise, subtracting 1 from the number of knocks, and turning to 2; 6, if knock is detected, turning to 1, otherwise, sending out an alarm signal and ending; the safety helmet is convenient and fast to use, good in reliability and free of any damage.

Description

Technical Field

[0001] This invention relates to an alarm method, and more particularly to a method for triggering an alarm by striking a safety helmet. Background Technology

[0002] In high-safety environments such as chemical plants, docks, and mines, safety helmets worn by workers are typically equipped with locators to effectively manage their movements. These locators also function as alarms, allowing workers to immediately activate a remote SOS alarm when they discover a hazard or are in a dangerous environment. This alerts management personnel to rush to the scene for assistance, effectively reducing property damage and personal injury at the work site. Currently, the locators on safety helmets are usually connected to an alarm button, which is installed on the outside of the helmet. Workers can press the alarm button to activate it in case of danger. However, work sites are generally outdoors in harsh environments. Besides exposure to direct sunlight, the alarm button is also susceptible to damage from rain, snow, fog, dust, and corrosive gases, making it easily damaged (although some protective measures can be implemented, this increases the production and installation costs of the locator), affecting its normal use. Furthermore, since workers press the alarm button blindly while wearing a safety helmet, they often cannot press it quickly and have to fumble around on the helmet, making it inconvenient and hindering quick and easy alarm activation. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for triggering an alarm by tapping a safety helmet. The safety helmet does not need to be equipped with alarm buttons or similar devices. The alarm can be triggered simply by tapping the safety helmet a certain number of times. The method is convenient, quick and reliable, and will not cause any damage to the safety helmet. It can also avoid false alarms.

[0004] The technical solution of this invention:

[0005] A method for triggering an alarm by striking a safety helmet, specifically: a locator is installed inside the safety helmet. The locator's positioning circuit contains a dual-axis accelerometer. The communication port of the dual-axis accelerometer is connected to the sensor communication port of the central processing unit in the positioning circuit. The dual-axis accelerometer has two measuring axes: an X-axis and a Z-axis, which are set perpendicular to each other. When the safety helmet is placed with the top facing upwards, the Z-axis of the dual-axis accelerometer is vertical. When the safety helmet is struck, the vibration generated by the strike causes a change in the signal output by the dual-axis accelerometer. The central processing unit receives the signal output by the dual-axis accelerometer through the sensor communication port and determines whether to trigger an alarm based on the signal output by the dual-axis accelerometer. The specific steps are as follows:

[0006] Step 1: Set the number of taps to 0;

[0007] Step 2: The central processing unit receives the Z-axis data (i.e., the acceleration value of the Z-axis) output by the dual-axis accelerometer. If the sign of the Z-axis data is the same as the sign of the Z-axis data when the helmet is placed with the top facing up, then proceed to step 3; otherwise, proceed to step 2.

[0008] The central processing unit (CPU) can monitor whether the safety helmet is worn correctly in real time by detecting Z-axis data. When the worker wears the safety helmet correctly, due to the influence of gravity, the sign of the Z-axis data received by the CPU is the same as when the safety helmet is placed with the top facing up. If the sign of the Z-axis data received by the CPU is different from when the safety helmet is placed with the top facing up, it means that the safety helmet is placed with the top facing down and is not worn correctly.

[0009] When a helmet is not worn correctly, any knocking alarms triggered will be considered invalid. This also eliminates false alarms caused by the helmet shaking or accidentally rolling off during transportation.

[0010] Step 3: The central processing unit receives the X-axis data (i.e., the acceleration value of the X-axis) output by the dual-axis accelerometer. When the absolute value of the X-axis data is greater than the set value, timing starts and the X-axis data is monitored at the same time. Timing stops when the absolute value of the X-axis data is less than the set value. Then, a set delay time is added to eliminate the influence of the rebound wave generated during the tap. If the time obtained by timing is greater than the set minimum duration but less than the set maximum duration, the number of taps is incremented by 1 and the process proceeds to step 4. Otherwise, the process proceeds to step 2.

[0011] When the helmet is struck, the X-axis data will change. The X-axis data represents the striking force. When both the striking force and the striking duration meet the set requirements, it is counted as one strike.

[0012] Step 4: The central processing unit determines whether the number of taps is the set number of taps. If yes, proceed to step 6; otherwise, proceed to step 5.

[0013] Step 5: The central processing unit starts timing and monitors the X-axis data. Timing stops when the absolute value of the X-axis data is greater than the set value. If the time obtained by timing is greater than the set minimum interval time but less than the set maximum interval time, then proceed to step 2. Otherwise, decrease the number of taps by 1 and proceed to step 2.

[0014] When a safety helmet is struck, the interval between each strike must meet the set interval requirement;

[0015] Step 6: The central processing unit starts timing according to the set time interval and monitors the X-axis data at the same time; if the absolute value of the X-axis data is found to be greater than the set value within the set time interval, then proceed to step 1; otherwise, proceed to step 7.

[0016] Step 7: The central processing unit sends an alarm signal through the functional module in the positioning circuit to end the operation.

[0017] Once the set number of taps is reached, tapping continues to be monitored within the set time interval. If no more taps are detected, the central processing unit sends an alarm signal to trigger the functional module to alarm. Otherwise, the tap count is reset to 0, and the tapping detection is restarted. This prevents the alarm from being triggered by regular, continuous, non-human tapping.

[0018] The positioner is installed on the inner top surface of the safety helmet.

[0019] When the helmet is placed with the top facing upwards, the positive direction of the Z-axis of the dual-axis accelerometer is set upwards, and the two ends of the X-axis of the dual-axis accelerometer are respectively facing the left and right sides of the helmet.

[0020] A triaxial accelerometer can be used to replace a biaxial accelerometer. The mutually perpendicular X-axis and Z-axis of the triaxial accelerometer can replace the X-axis and Z-axis of the biaxial accelerometer, respectively. The Y-axis of the triaxial accelerometer is not used.

[0021] The model number of the triaxial accelerometer is LIS3DH.

[0022] The set value is 2m / s 2 ~12m / s 2 The set delay time is 20ms to 50ms, the set minimum duration is 5ms to 20ms, the set maximum duration is 10ms to 100ms, the set minimum interval is 200ms to 400ms, the set maximum interval is 800ms to 1200ms, the set number of taps is 3 to 10, and the set timer is 1s.

[0023] In step 1, the central processing unit first detects the location of the locator through the positioning circuit. If the locator is within the set map electronic fence, the number of taps is set to 0, and the process proceeds to step 2; otherwise, the process proceeds to step 1.

[0024] In step 7, the functional module includes a wireless communication module and an audible and visual alarm module. The central processing unit sends out an SOS wireless alarm signal and an audible and visual alarm signal through the wireless communication module and the audible and visual alarm module, respectively.

[0025] To use this helmet alarm, wear the helmet correctly on your head, then tap the side of the helmet with your hand, following the preset number of taps.

[0026] The beneficial effects of this invention are:

[0027] 1. This invention utilizes an accelerometer to detect the impact signal on the safety helmet and determines whether an alarm needs to be triggered based on the data changes of the accelerometer's measuring axis. When an alarm is triggered due to danger, simply tap the safety helmet a certain number of times. It is convenient and quick to use, eliminating the need for alarm buttons or similar devices on the outside of the safety helmet. This avoids damage from harsh external environments, ensures high reliability, and does not cause any damage to the safety helmet, maintaining its intact and aesthetically pleasing appearance.

[0028] 2. This invention uses an accelerometer to detect whether the safety helmet is worn correctly. The alarm will only be triggered when the safety helmet is worn correctly, thus avoiding false alarms.

[0029] 3. This invention utilizes the positioning function of a locator to detect whether the safety helmet is located within a pre-set map electronic fence. An alarm is only triggered when the helmet is within the map electronic fence, thus avoiding false alarms when the helmet is outside the monitoring environment.

[0030] 4. The alarm sensitivity of this invention is as high as 98%, and the false explosion rate is as low as three per thousand. Attached Figure Description

[0031] Figure 1 One of the waveforms of the X-axis data from a triaxial accelerometer;

[0032] Figure 2 The second waveform of the X-axis data from the triaxial accelerometer;

[0033] Figure 3 The third waveform diagram of the X-axis data from the triaxial accelerometer. Detailed Implementation

[0034] The method for triggering an alarm by striking a safety helmet is as follows: A locator is installed on the inner top surface of the safety helmet. The locator's positioning circuit contains a dual-axis accelerometer. The communication port of the dual-axis accelerometer is connected to the sensor communication port of the central processing unit in the positioning circuit. The dual-axis accelerometer has two measuring axes: the X-axis and the Z-axis, which are set perpendicular to each other. When the top of the safety helmet is facing upwards, the Z-axis of the dual-axis accelerometer is vertical, with its positive direction pointing upwards. The two ends of the X-axis of the dual-axis accelerometer point towards the left and right sides of the safety helmet, respectively. When the safety helmet is struck, the vibration caused by the strike changes the signal output by the dual-axis accelerometer. The central processing unit receives the signal output by the dual-axis accelerometer through the sensor communication port and determines whether to trigger an alarm based on the signal output by the dual-axis accelerometer. The specific steps are as follows:

[0035] Step 1: The central processing unit first detects the location of the locator through the positioning circuit. If the locator is within the set map electronic fence, the number of taps is set to 0 and the process proceeds to Step 2; otherwise, the process proceeds to Step 1.

[0036] Step 2: The central processing unit receives the Z-axis data (i.e., the acceleration value of the Z-axis) output by the dual-axis accelerometer. If the sign of the Z-axis data is the same as the sign of the Z-axis data when the helmet is placed with the top facing up, then proceed to step 3; otherwise, proceed to step 2.

[0037] The central processing unit (CPU) can monitor whether the safety helmet is worn correctly in real time by detecting Z-axis data. When the worker is wearing the safety helmet correctly, the sign of the Z-axis data received by the CPU is the same as when the helmet is placed with the top facing upwards (negative due to gravity, approximately -9.81 m / s²). 2 If the sign of the Z-axis data received by the central processing unit is different from that when the helmet is placed with the top facing up (it is a positive value), it means that the helmet is placed with the top facing down and is not worn correctly.

[0038] When a helmet is not worn correctly, any knocking alarms triggered will be considered invalid. This also eliminates false alarms caused by the helmet shaking or accidentally rolling off during transportation.

[0039] Step 3: The central processing unit receives the X-axis data (i.e., the acceleration value of the X-axis) output by the dual-axis accelerometer. When the absolute value of the X-axis data is greater than the set value, timing starts and the X-axis data is monitored at the same time. Timing stops when the absolute value of the X-axis data is less than the set value. Then, a set delay time is added to eliminate the influence of the rebound wave generated during the tap. If the time obtained by timing is greater than the set minimum duration but less than the set maximum duration, the number of taps is incremented by 1 and the process proceeds to step 4. Otherwise, the process proceeds to step 2.

[0040] When the helmet is struck, the X-axis data will change. The X-axis data represents the striking force. When both the striking force and the striking duration meet the set requirements, it is counted as one strike.

[0041] Step 4: The central processing unit determines whether the number of taps is the set number of taps. If yes, proceed to step 6; otherwise, proceed to step 5.

[0042] Step 5: The central processing unit starts timing and monitors the X-axis data. Timing stops when the absolute value of the X-axis data is greater than the set value. If the time obtained by timing is greater than the set minimum interval time but less than the set maximum interval time, then proceed to step 2. Otherwise, decrease the number of taps by 1 and proceed to step 2.

[0043] When a safety helmet is struck, the interval between each strike must meet the set interval requirement;

[0044] Step 6: The central processing unit starts timing according to the set time interval and monitors the X-axis data at the same time; if the absolute value of the X-axis data is found to be greater than the set value within the set time interval, then proceed to step 1; otherwise, proceed to step 7.

[0045] Step 7: The central processing unit sends an alarm signal through the functional module in the positioning circuit to end the operation.

[0046] Once the set number of taps is reached, tapping continues to be monitored within the set time interval. If no more taps are detected, the central processing unit sends an alarm signal to trigger the functional module to alarm. Otherwise, the tap count is reset to 0, and the tapping detection is restarted. This prevents the alarm from being triggered by regular, continuous, non-human tapping.

[0047] A triaxial accelerometer is used instead of a biaxial accelerometer. The mutually perpendicular X-axis and Z-axis of the triaxial accelerometer replace the X-axis and Z-axis of the biaxial accelerometer, respectively. The Y-axis of the triaxial accelerometer is not used.

[0048] The model number of the triaxial accelerometer is LIS3DH.

[0049] The set value is 6 m / s 2 The set delay time is 40ms, the set minimum duration is 8ms, the set maximum duration is 30ms, the set minimum interval time is 300ms, the set maximum interval time is 1000ms, the set number of taps is 3, and the set timer time is 1 second.

[0050] In step 7, the functional module includes a wireless communication module and an audible and visual alarm module. The central processing unit sends out an SOS wireless alarm signal and an audible and visual alarm signal through the wireless communication module and the audible and visual alarm module, respectively.

[0051] To use this helmet alarm, wear the helmet correctly on your head, then tap the side of the helmet with your hand, following the preset number of taps.

[0052] The set values, delay time, minimum duration, maximum duration, minimum interval, and maximum interval were obtained through experiments. The specific experimental method is as follows:

[0053] When the experimenter was informed that a single tap would trigger the alarm, the experimenter, wearing a safety helmet, tapped the helmet once from the right side, and then repeated the alarm operation twice. At this point, the waveform of the X-axis data from the triaxial accelerometer was as follows: Figure 1 As shown in the figure, after each strike, the first waveform undergoes multiple changes. This is the rebound wave caused by the movement of the helmet under the action of the liner when the force ends. The waveforms of the two subsequent repeated alarm operations are similar to the previous one. The obvious change in the X-axis can be identified as a single strike. Waveform changes caused by other methods, such as moving the helmet, are not like this (resulting in sharp waveforms). Non-human strikes can be ruled out based on the waveform duration. The amplitude and width of the first waveform can be used as a reference when determining the set value, setting the minimum duration, and setting the maximum duration. The width of the rebound wave after the first waveform can be used as a reference when determining the set delay time.

[0054] When the experimenter was instructed that the alarm would be triggered only after two taps, the experimenter, wearing a safety helmet, tapped the helmet twice from the right side. This process was then repeated twice more. At this point, the waveform of the X-axis data from the triaxial accelerometer was as follows: Figure 2 As shown in the figure, there is a certain time interval between the two taps, and the waveform of the two repeated alarm operations is similar to that of the previous one.

[0055] When the experimenter was instructed that the alarm would be triggered after three taps, the experimenter, wearing a safety helmet, tapped the helmet three times from the right side. This process was then repeated. The waveform of the X-axis data from the triaxial accelerometer was as follows: Figure 3 As shown in the figure, the time interval between the three taps is basically consistent, and the waveform of the subsequent repeated alarm operation is similar to that of the previous one. The time interval between the three taps can be used as a reference when determining the minimum and maximum interval times. If the time interval between the three taps is too large, it indicates that the tapping may be caused by a false trigger or accidental collision with other objects. If the time interval is too small, it indicates that the tapping may be caused by other mechanical vibrations.

[0056] The above experiments require multiple people to wear safety helmets and perform tapping tests. Only in this way can the parameters be applicable to most people, making the judgment of the central processing unit reliable, preventing false triggering, and ensuring sensitive tapping.

Claims

1. A method for triggering an alarm by striking a safety helmet, characterized in that: The locator is installed inside the safety helmet. The locator's positioning circuit contains a dual-axis accelerometer. The communication port of the dual-axis accelerometer is connected to the sensor communication port of the central processing unit (CPU) in the positioning circuit. The dual-axis accelerometer has two measuring axes: the X-axis and the Z-axis, which are set perpendicular to each other. When the safety helmet is placed with the top facing upwards, the Z-axis of the dual-axis accelerometer is vertical. When the safety helmet is struck, the vibration causes a change in the signal output by the dual-axis accelerometer. The CPU receives the signal output by the dual-axis accelerometer through the sensor communication port and determines whether to trigger an alarm based on the signal. The specific steps are as follows: Step 1: Set the number of taps to 0; Step 2: The central processing unit receives the Z-axis data output by the dual-axis accelerometer. If the sign of the Z-axis data is the same as the sign of the Z-axis data when the helmet is placed with the top facing up, then proceed to step 3; otherwise, proceed to step 2. Step 3: The central processing unit receives the X-axis data output by the dual-axis accelerometer. When the absolute value of the X-axis data is greater than the set value, timing starts and the X-axis data is monitored at the same time. Timing stops when the absolute value of the X-axis data is less than the set value, and then a set delay time is applied. If the time obtained by timing is greater than the set minimum duration but less than the set maximum duration, the number of taps is incremented by 1 and the process proceeds to step 4. Otherwise, the process proceeds to step 2. Step 4: The central processing unit determines whether the number of taps is the set number of taps. If it is, proceed to step 6; otherwise, proceed to step 5. Step 5: The central processing unit starts timing and monitors the X-axis data. Timing stops when the absolute value of the X-axis data is greater than the set value. If the time obtained by timing is greater than the set minimum interval time but less than the set maximum interval time, then proceed to step 2. Otherwise, decrease the number of taps by 1 and proceed to step 2. Step 6: The central processing unit starts timing according to the set time interval and monitors the X-axis data at the same time; if the absolute value of the X-axis data is found to be greater than the set value within the set time interval, then proceed to step 1; otherwise, proceed to step 7. Step 7: The central processing unit sends an alarm signal through the functional module in the positioning circuit to end the operation.

2. The method for triggering an alarm by striking a safety helmet according to claim 1, characterized in that: The locator is installed on the inner top surface of the helmet.

3. The method for triggering an alarm by striking a safety helmet according to claim 1, characterized in that: When the safety helmet is placed with the top facing upwards, the positive direction of the Z-axis of the dual-axis accelerometer is set upwards, and the two ends of the X-axis of the dual-axis accelerometer are respectively facing the left and right sides of the safety helmet.

4. The method for triggering an alarm by striking a safety helmet according to claim 1, characterized in that: The biaxial accelerometer is replaced by a triaxial accelerometer, with the mutually perpendicular X-axis and Z-axis of the triaxial accelerometer replacing the X-axis and Z-axis of the biaxial accelerometer, respectively.

5. The method for triggering an alarm by striking a safety helmet according to claim 4, characterized in that: The model number of the triaxial accelerometer is LIS3DH.

6. The method for triggering an alarm by striking a safety helmet according to claim 1, characterized in that: The set value is 2m / s 2 ~12m / s 2 The set delay time is 20ms to 50ms, the set minimum duration is 5ms to 20ms, the set maximum duration is 10ms to 100ms, the set minimum interval is 200ms to 400ms, the set maximum interval is 800ms to 1200ms, the set number of taps is 3 to 10, and the set timer is 1s.

7. The method for triggering an alarm by striking a safety helmet according to claim 1, characterized in that: In step 1, the central processing unit first detects the location of the locator through the positioning circuit. If the locator is within the set map electronic fence, the number of taps is set to 0, and the process proceeds to step 2; otherwise, the process proceeds to step 1.

8. The method for triggering an alarm by striking a safety helmet according to claim 1, characterized in that: In step 7, the functional module includes a wireless communication module and an audible and visual alarm module. The central processing unit sends out wireless alarm signals and audible and visual alarm signals through the wireless communication module and the audible and visual alarm module, respectively.

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