2.4 G-based low-power-consumption charging-free personnel positioning safety helmet and positioning system
By utilizing 2.4G low-power communication and dynamic broadcast frequency adjustment, combined with an accelerometer and a disposable battery, the smart helmet achieves long battery life and an integrated design, solving the problems of short battery life, cumbersome wearing, and high deployment costs in existing technologies, and constructing an efficient positioning system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-08
- Publication Date
- 2026-05-12
AI Technical Summary
Existing smart safety helmets have short battery life, are cumbersome to wear, have positioning tags that are separate from the helmet, and are costly to deploy and maintain, making it difficult to meet the requirements for long battery life and seamless wearing in high-risk work scenarios.
It adopts a 2.4G low-power communication, accelerometer and disposable battery design, combined with dynamic broadcast frequency adjustment and anti-tamper device to realize the integration of positioning tag and safety helmet. It builds a complete positioning system through positioning gateway and relay gateway, and optimizes power consumption management and network coverage.
It achieves zero charging throughout the entire life cycle of the safety helmet, lightweight positioning tags with no additional burden, eliminates tag removal vulnerabilities, reduces deployment and maintenance costs, and adapts to long-distance data transmission in complex environments.
Smart Images
Figure CN122004562A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of Internet of Things positioning technology and industrial safety equipment technology, specifically to a low-power, non-charging personnel positioning safety helmet and positioning system based on 2.4G. Background Technology
[0002] In high-risk work scenarios such as construction, mining, and power line inspection, safety helmets are the core protective equipment to ensure the safety of workers. With the increasing demand for intelligent management, smart safety helmets with positioning functions have emerged in existing technologies. They achieve location tracking through positioning technologies such as UWB (Ultra-Wideband), RFID (Radio Frequency Identification), and Bluetooth beacons, making it easier for managers to grasp data such as the distribution of workers, working hours, and efficiency.
[0003] However, existing smart safety helmets generally suffer from the following drawbacks: First, battery anxiety and charging burden are prominent issues. Smart safety helmets equipped with high-power components such as GPS and 4G modules require frequent charging, which not only increases the user's daily maintenance burden but also leads to interruption of positioning data and loss of monitoring continuity if they are not charged in time during construction operations. Second, the cumbersome wearing experience and separate design issues are also significant. Many positioning solutions use additional items such as wristbands and badges, or separate positioning tags from the safety helmet, resulting in a large overall weight (generally around 400g), poor wearing experience, and a management loophole of "the person is wearing it, but the positioning tag is not." In addition, high deployment and maintenance costs are also an important factor restricting their promotion. Positioning systems such as UWB and Bluetooth AoA require the deployment of a large number of positioning base stations, which have high requirements for installation location, power supply, and backhaul network. The initial investment is large, and the scalability is poor, resulting in high maintenance costs in the later stages.
[0004] Therefore, there is an urgent need for an intelligent personnel positioning solution that can be deeply integrated with safety helmets, achieve long battery life without charging, and be worn without any noticeable discomfort. Summary of the Invention
[0005] This invention aims to solve the technical problems of existing smart safety helmets, such as short battery life, cumbersome wearing, and separation of positioning tags from the safety helmet, and provides a low-power, recharge-free personnel positioning safety helmet and positioning system based on 2.4G.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On one hand, the present invention provides a low-power, recharge-free personnel positioning safety helmet based on 2.4G, comprising: The helmet itself; The positioning tag is fixed to the helmet body; Location tags include: A 2.4G wireless transceiver circuit is used to broadcast 2.4G wireless data packets containing unique identification information of the location tag; An accelerometer is used to collect motion data of the wearer. Disposable batteries provide power for the positioning tags; The main control unit is electrically connected to the 2.4G wireless transceiver circuit and the accelerometer. Based on the motion state data output by the accelerometer, the main control unit determines whether the wearer's motion state is in motion mode or stationary mode. Based on the determined motion state, the main control unit dynamically adjusts the broadcast frequency of the 2.4G wireless transceiver circuit. The broadcast frequency in motion mode is higher than that in stationary mode.
[0007] Furthermore, determining the wearer's movement status specifically includes: When the positioning tag is in stationary mode, the main control unit periodically acquires motion state data collected by the accelerometer at a first acquisition interval and sets a first count value to record the number of times motion state is detected consecutively. Each acquired data point is compared with a preset motion threshold. If the data exceeds the threshold, the first count value is incremented; otherwise, the first count value is cleared. When the first count value reaches the first preset value, the main control unit determines that the wearer has entered a movement state and switches the positioning tag to movement mode; When the positioning tag is in motion, the main control unit periodically acquires motion state data collected by the accelerometer at a second acquisition interval, and sets a second count value to record the number of times a stationary state is detected consecutively. Each acquired data point is compared with a preset motion threshold. If the motion threshold is not exceeded, the second count value is incremented; otherwise, the second count value is cleared. When the second count value reaches the second preset value, the main control unit determines that the wearer has entered a stationary state and switches the positioning tag to stationary mode.
[0008] Furthermore, the location tag has both factory default and activation modes: In factory default mode, the 2.4G wireless transceiver circuit broadcasts at the first broadcast frequency; In active mode, the main control unit broadcasts at a dynamically adjusted frequency based on the wearer's movement.
[0009] Furthermore, the broadcast frequency in motion mode is 5 times per second, and the broadcast frequency in stationary mode is 1 time per second.
[0010] Furthermore, the positioning tag also includes a waterproof device and an anti-tamper device, with the waterproof device covering the outside of the positioning tag; preferably, the anti-tamper device is a push-button anti-tamper micro switch.
[0011] Furthermore, the disposable battery is a 2000mAh lithium manganese battery, the overall weight of the positioning tag is less than or equal to 35 grams, and the positioning tag is fixed to the helmet body with high-viscosity adhesive.
[0012] Furthermore, the positioning tag also includes a buzzer and LED status indicator lights connected to the main control unit.
[0013] On the other hand, the present invention also provides a positioning system, comprising: Multiple of the aforementioned safety helmets; At least one positioning gateway is used to receive 2.4G wireless data packets broadcast by the positioning safety helmet, measure the RSSI value of each wireless data packet, and aggregate multiple RSSI values from the same positioning safety helmet within a preset aggregation time window to generate an aggregated data packet containing aggregated data, serial number and time identifier before broadcasting it. At least one relay gateway is required to receive and forward aggregated data packets broadcast by the location gateway. The public network gateway is used to receive aggregated data packets forwarded by the last-level relay gateway and upload them to the cloud platform or host computer via the external network.
[0014] Furthermore, the relay gateway has a self-learning synchronization mechanism: After the relay gateway is powered on, it first enters the listening mode. By receiving multiple aggregated data packets broadcast by the upstream gateway, it analyzes the arrival time pattern of each data packet and autonomously learns to establish a wake-up schedule that is synchronized with the sending time of the upstream gateway. After synchronization is established, the relay gateway switches to intermittent working mode, only waking up and opening the receiving window at the time corresponding to the wake-up schedule, and remaining in sleep mode at other times. After successfully receiving the aggregated data packet from the upstream gateway within the receiving window, the relay gateway updates the data packet and forwards it to the downstream gateway within the subsequent sending window.
[0015] Furthermore, at the end of each aggregation time window, the positioning gateway extracts the feature values from multiple RSSI values from the same positioning helmet, encapsulates them together with the identification information and time stamp of the corresponding positioning helmet into an aggregated data packet, and broadcasts the aggregated data packet repeatedly a preset number of times. When receiving aggregated data packets, the relay gateway filters out duplicate data packets based on the sequence number in the data packet and forwards only the first valid data packet received.
[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses an accelerometer to sense the movement of people in real time and dynamically adjusts the wireless broadcast frequency accordingly. Combined with an ultra-low power 2.4G communication unit and a disposable high-capacity battery, it achieves a daily power consumption of milliamperes. Theoretically, the positioning tag can be used for the entire lifespan of the safety helmet (more than 30 months) without charging or battery replacement, completely solving the battery anxiety of smart safety helmets.
[0017] 2. This invention features a lightweight design for the positioning tag (≤35g) and integrates it with the helmet body using high-viscosity adhesive, resulting in virtually no extra burden on the wearer. Furthermore, the combination of a physical tamper-proof switch and software logic effectively prevents the tag from being intentionally removed, thus eliminating management loopholes.
[0018] 3. This invention employs a waterproof device, enabling the safety helmet to meet national safety standards while possessing intelligent functions, and to be adapted to daily use scenarios such as workers washing their safety helmets, thus ensuring the reliability and durability of the product.
[0019] 4. By distinguishing between factory delivery mode and activation mode, this invention optimizes the power consumption management of the entire product lifecycle from production to use, and extends the storage and distribution cycle.
[0020] 5. This invention integrates a positioning safety helmet with a positioning gateway, a relay gateway, and a public network gateway to form a complete positioning system. The positioning gateway aggregates multiple RSSI values from the same positioning safety helmet within a preset aggregation time window, extracts feature values, and encapsulates them with identification information, serial number, and time stamp into an aggregated data packet before broadcasting, significantly reducing network data throughput and improving transmission efficiency. The relay gateway employs a self-learning synchronization mechanism. After power-on, it analyzes the broadcast patterns of the upstream gateway through a listening mode, autonomously learns and establishes a wake-up schedule, and then switches to an intermittent working mode, receiving and forwarding data only during wake-up times, remaining in a dormant state the rest of the time, significantly reducing power consumption and enabling long-term operation on battery power. Simultaneously, the relay gateway can be cascaded in multiple levels, effectively extending network coverage and adapting to the long-distance data transmission needs in complex environments. The public network gateway uploads the aggregated data packets forwarded by the last-level relay gateway to the cloud platform for location calculation and intelligent management. Through the above system-level design, this invention achieves efficient data aggregation, ultra-low power consumption of relays, flexible coverage expansion, and simple deployment, constructing a complete positioning closed loop from terminal perception and data transmission to cloud analysis. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the safety helmet structure of the present invention.
[0022] Figure 2 This is a block diagram showing the connection of each module in the positioning tag of the present invention (disposable batteries are not shown).
[0023] Figure 3 This is a block diagram of the positioning system of the present invention. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0025] In the description of this invention, it should be noted that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; of course, they can also refer to a mechanical connection or an electrical connection; furthermore, they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0027] like Figure 1 and Figure 2 As shown, this invention provides a low-power, recharge-free personnel positioning safety helmet based on 2.4G, comprising a helmet body and a positioning tag fixed to the helmet body (inner or outer top). The positioning tag includes a 2.4G wireless transceiver circuit for broadcasting 2.4G wireless data packets containing the unique identifier of the positioning tag, an accelerometer for collecting motion state data of the wearer, and a disposable battery for providing power to the positioning tag. A main control unit is electrically connected to both the 2.4G wireless transceiver circuit and the accelerometer. Based on the motion state data output by the accelerometer, the main control unit determines whether the wearer's motion state is in motion or stationary mode. Then, based on the determined motion state, it dynamically adjusts the broadcast frequency of the 2.4G wireless transceiver circuit; the broadcast frequency in motion mode is higher than that in stationary mode. Through this mechanism, this invention achieves on-demand broadcasting. High-frequency broadcasting ensures real-time positioning during personnel activity, while automatically reducing the frequency to lower power consumption when the personnel are stationary. Combined with a disposable battery power supply, it can operate without charging throughout the entire lifespan of the safety helmet.
[0028] The 2.4G wireless transceiver circuit of this invention is a known existing electronic component in the art and can be implemented using commercially available 2.4G radio frequency chips. Those skilled in the art can select appropriate models according to actual needs, and this invention does not limit its specific internal circuit structure.
[0029] The main control unit of this invention is a known existing electronic component in the art, and can be implemented using a low-power microcontroller (MCU) or a system-on-a-chip (SoC). Those skilled in the art can select a suitable model according to functional requirements and power consumption budget, and this invention does not limit its specific internal architecture.
[0030] As a preferred implementation, the main control unit adopts a low-power system-on-chip (SoC) solution integrated with the 2.4G wireless transceiver circuit, such as the Nordic nRF52832. This chip integrates an ARM Cortex-M4 core, a 2.4G RF transceiver, non-volatile memory, an RTC timer, multiple GPIO interfaces, and an interrupt controller, which can meet all the functional requirements of this invention.
[0031] In some embodiments, determining the wearer's movement state specifically includes: When the positioning tag is in stationary mode, the main control unit periodically acquires motion state data collected by the accelerometer at a first acquisition interval and sets a first count value to record the number of times motion state is detected consecutively. Each acquired data point is compared with a preset motion threshold. If the data exceeds the threshold, the first count value is incremented; otherwise, the first count value is cleared. When the first count value reaches the first preset value, the main control unit determines that the wearer has entered a movement state and switches the positioning tag to movement mode; When the positioning tag is in motion, the main control unit periodically acquires motion state data collected by the accelerometer at a second acquisition interval, and sets a second count value to record the number of times a stationary state is detected consecutively. Each acquired data point is compared with a preset motion threshold. If the motion threshold is not exceeded, the second count value is incremented; otherwise, the second count value is cleared. When the second count value reaches the second preset value, the main control unit determines that the wearer has entered a stationary state and switches the positioning tag to stationary mode.
[0032] As a preferred implementation, the parameters in the above motion state determination logic can be configured as follows: The preferred first data acquisition interval is 3 seconds, meaning that when the positioning tag is in stationary mode, the main control unit wakes up every 3 seconds to acquire the output data from the accelerometer. The preferred first preset value is 3 times, meaning that when the data acquired for 3 consecutive times (a total of 9 seconds) exceeds the motion threshold, it is determined that the wearer has entered a motion state.
[0033] The second acquisition interval is preferably 10 seconds, meaning that when the positioning tag is in motion mode, the main control unit wakes up once every 10 seconds and acquires the output data of the accelerometer. The second preset value is preferably 6 times, meaning that when the data collected for 6 consecutive times (a total of 60 seconds) does not exceed the motion threshold, it is determined that the wearer has entered a stationary state.
[0034] The motion threshold is set based on the following: the angular velocity output by the accelerometer (gyroscope) is a three-dimensional vector value (X-axis, Y-axis, Z-axis). Actual measurements show that when the positioning tag is stationary, the angular velocity values in all three axes fluctuate below 40. Therefore, in this embodiment, the motion threshold is preferably set to 40. When the angular velocity value of any axis exceeds 40, the collected data is determined to have "exceeded the motion threshold"; only when the angular velocity values in all three axes do not exceed 40 is the collected data determined to have "not exceeded the motion threshold".
[0035] With the above parameter configuration, in stationary mode, this invention employs a 3-second data acquisition interval and a 3-times continuous confirmation threshold, ensuring sufficient response sensitivity—switching to motion mode within 9 seconds of the wearer starting to move—while effectively avoiding false wake-ups caused by occasional minor movements (such as turning the head, shaking the leg, or briefly standing up). In motion mode, a 10-second data acquisition interval and a 6-times continuous confirmation threshold are used; no movement is detected for 60 consecutive seconds before the system is considered stationary. This effectively avoids frequent mode switching caused by short pauses (such as waiting for an elevator, tying shoelaces, or standing still to look around). The longer data acquisition interval also further reduces system power consumption in motion mode.
[0036] Based on actual testing, the power consumption of the positioning tag after configuring the above parameters can be calculated using the following formula: In static mode, the broadcast frequency is 1 time / 1 second. According to actual measurement, the average current of a single broadcast cycle is 59.3μA. If the static mode lasts for 8 hours a day, the average daily power consumption in static mode is: 8h × 59.3μA = 474.4μAh.
[0037] In sports mode, the broadcast frequency is 5 times / 1 second. According to actual measurement, the average current of a single broadcast cycle is 62.3μA. If you exercise for 16 hours a day, the average daily power consumption in sports mode is: 16h × 62.3μA = 996.8μAh.
[0038] The average daily total power consumption is 474.4μAh + 996.8μAh = 1471.2μAh ≈ 1.47mAh.
[0039] Using a 2000mAh disposable lithium manganese battery, and considering a discharge efficiency of 0.8 (with a safety margin), the theoretical battery life is: 2000mAh × 0.8 ÷ 1.47mAh ≈ 1088 days, which is more than 30 months, completely covering the mandatory scrapping cycle of the safety helmet, and achieving true charging-free operation.
[0040] The above-mentioned dynamic adjustment of the broadcast frequency of the 2.4G wireless transceiver circuit based on the determined motion state is reflected in the time-division broadcast mechanism. This time-division broadcast mechanism ensures that sufficient positioning data sampling density is provided when people are active, and automatically reduces the broadcast frequency when people are stationary to reduce unnecessary power consumption.
[0041] In some embodiments, the location tag has both factory default and activation modes: In factory default mode, the 2.4G wireless transceiver circuit broadcasts at the first broadcast frequency; In active mode, the main control unit broadcasts at a dynamically adjusted frequency based on the wearer's movement.
[0042] The factory-delivered mode is applied to the warehousing, transportation, and distribution stages after the positioning tags are manufactured. In this mode, the 2.4G wireless transceiver circuit broadcasts at a first broadcast frequency. The first broadcast frequency is preferably 1 time / 1 second, that is, one 2.4G wireless data packet is broadcast every second. This frequency is sufficient to meet the basic identification needs in scenarios such as warehouse management and inventory counting, while also having low power consumption, which can avoid excessive consumption of disposable battery power by the positioning tags before they are put into use.
[0043] When a location tag is issued to a worker and enters the signal coverage area of the location gateway for the first time, the location gateway can send an activation command to the location tag. After receiving the activation command, the location tag is controlled by the main control unit to switch from factory mode to activation mode.
[0044] The activation mode is the normal working mode of the positioning tag. In this mode, the main control unit dynamically adjusts the broadcast frequency of the 2.4G wireless transceiver circuit according to the motion state data collected in real time by the accelerometer and the aforementioned judgment logic: when the mode is judged to be stationary, it broadcasts at the stationary mode broadcast frequency (preferably 1 time / 1 second); when the mode is judged to be in motion, it broadcasts at the motion mode broadcast frequency (preferably 5 times / 1 second).
[0045] The activation command can be triggered in ways not limited to the examples above. For instance, the location tag can also switch from factory default mode to activation mode via near-field communication, Bluetooth pairing, or QR code activation. Once in activation mode, the location tag will continue to operate until the battery is depleted, without needing to switch back to factory default mode.
[0046] It should be noted that the first broadcast frequency in the factory mode can be the same as the broadcast frequency in the static mode (e.g., both are 1 time / 1 second), or it can be set to a lower frequency (e.g., 2 times / 1 second or lower). The specific configuration can be flexibly configured according to factors such as the length of the warehousing cycle and inventory management needs, all of which are within the protection scope of this invention.
[0047] In some embodiments, the positioning tag is also equipped with a buzzer and an LED status indicator that are electrically connected to the main control unit.
[0048] The buzzer is used to assist in implementing business functions, including proximity alarms to hazards and one-click recall.
[0049] Base stations are deployed in areas requiring control. The base stations and positioning tags are connected wirelessly. Managers select the corresponding management type (such as proximity alarm, one-click recall, etc.) and set trigger conditions (such as RSSI threshold, area range, etc.) through the Magic Cube configuration platform. After completing the configuration, the information is sent to the corresponding gateway.
[0050] When a person wearing an activated (activated mode) positioning helmet enters the area, the base station receives the 2.4G wireless data packets broadcast by the helmet, parses the unique identification information of the positioning tag, and measures the RSSI value. The higher the RSSI value, the closer the tag is to the base station. When the measured RSSI value meets the preset trigger conditions (such as exceeding the set RSSI threshold), the base station determines that the person has entered the alarm area and then sends an alarm command to the positioning helmet via wireless communication (such as a 2.4G wireless link).
[0051] The 2.4G wireless transceiver circuit of the safety helmet receives alarm commands and transmits them to the main control unit. The main control unit parses the commands and drives the buzzer to emit a sound with a specified rhythm. For example, a continuous high-frequency sound is emitted when approaching a hazard, and an intermittent sound is emitted when a one-button recall is activated, thus reminding personnel to be aware of the danger or to return as required. When personnel leave the alarm area or receive a stop command, the main control unit stops the buzzer from sounding.
[0052] The LED status indicator light is used solely for status verification during the switch between factory default mode and activation mode. In factory default mode, the tamper switch triggers the indicator light to flash red, yellow, and green alternately, accompanied by a buzzer sound, to verify that the tag is in normal factory condition. Once the tag is activated and enters normal operating mode (activation mode), the tamper switch only flashes the green indicator light, indicating that the tag is now activated. Through this design, the LED status indicator light provides an intuitive means of status verification for production testing and field activation.
[0053] In some embodiments, the positioning tag also includes waterproof and tamper-proof devices to improve the product's adaptability to harsh environments and the reliability of personnel positioning management.
[0054] A waterproof device covers the outside of the positioning tag to prevent dust, moisture, rain and other substances from penetrating the inside of the positioning tag, ensuring the long-term stable operation of the circuit system in harsh environments.
[0055] As a preferred embodiment, the waterproof device is a transparent, fully enclosed waterproof cover made of soft, transparent waterproof material (such as TPU, silicone, etc.), which tightly covers the outer shell of the positioning tag. The waterproof cover has a sound- and light-transmitting structure corresponding to the positions of the buzzer and LED indicator on the positioning tag to ensure that the audible and visual alarm signals can be transmitted normally; and a clearance structure is provided corresponding to the positions of the anti-tamper device to ensure that the anti-tamper function is not affected.
[0056] The waterproof device allows the positioning safety helmet of this invention to adapt to high dust and high humidity working environments such as construction sites, mines, and tunnels, and allows workers to clean the safety helmet by rinsing it with water in the summer without worrying about water damage to the positioning tag, significantly improving the product's environmental adaptability and service life.
[0057] The tamper protection device is used to generate a corresponding trigger signal when the positioning tag is illegally removed from the helmet body, so as to realize tamper protection alarm and management closed loop.
[0058] In a preferred embodiment, the anti-tamper device is a push-button microswitch. This microswitch is located at the bottom of the positioning tag and is specifically mounted on the safety helmet body using high-viscosity adhesive. The anti-tamper device generates a corresponding trigger signal when the positioning tag is illegally removed from the safety helmet body, thus achieving anti-tamper alarm and management closed loop. When the positioning tag enters the anti-tamper alarm state due to illegal removal, it needs to be unlocked through the backend management system. After logging into the system, the administrator enters the operation and maintenance management page, clicks the "Unlock" button in the operation column of the corresponding numbered device, and the system generates an unlock command and sends it to the positioning tag via the base station. After receiving the command and verifying its validity, the positioning tag exits the anti-tamper alarm state and resumes normal operation. It should be noted that the above-mentioned remote unlocking method of the backend management system is a prior art known in the art, and this invention does not specifically limit it.
[0059] In some embodiments, the disposable battery is a 2000mAh lithium-manganese battery, and the overall weight of the positioning tag is less than or equal to 35 grams. The positioning tag is fixed to the helmet body using high-viscosity adhesive. The positioning tag uses a 2000mAh lithium-manganese battery as its power source. This battery has advantages such as high energy density, low self-discharge rate, stable operating voltage, wide temperature range, high safety, no need for charging management, environmental friendliness, and significant cost advantages, providing a reliable guarantee for the positioning tag to achieve ultra-long battery life and charging-free operation. This invention controls the overall weight of the positioning tag to less than or equal to 35 grams, far lower than the typical weight of around 400 grams for existing smart helmets, resulting in almost no extra burden for the wearer and truly achieving "unfeeling wear." In addition, the positioning tag of the present invention is fixed to the helmet body with high-viscosity adhesive, specifically using 3M VHB double-sided tape (Very High Bond, ultra-high adhesive strength tape), which has the advantages of easy installation (no tools required, completed in seconds), strong adhesion (resistant to vibration and impact, resistant to wide temperature and high humidity), controllable disassembly (illegal disassembly alarm, authorized maintenance can be removed) and strong compatibility (suitable for various helmet materials, does not damage protective performance).
[0060] As a preferred option, the positioning tag is affixed to the top center or the back of the helmet. The top position minimizes signal obstruction, which is beneficial for wireless communication; the back position reduces interference with the wearer's vision. Both positions ensure a secure bond between the tag and the helmet.
[0061] The present invention also provides a positioning system that combines the aforementioned positioning safety helmet with a multi-level relay transmission network, which is suitable for personnel positioning and management in complex environments such as construction sites, underground mines, tunnels, and large warehouses.
[0062] The positioning system includes the following components: Multiple of the aforementioned safety helmets.
[0063] At least one positioning gateway, employing a 2.4G communication chip, is deployed at key locations within the work area, such as the top of a tower crane, the roof of a temporary building, or a high point in the center of the area. The positioning gateway receives 2.4G wireless data packets broadcast from the safety helmet, measures the RSSI value of each wireless data packet, and aggregates multiple RSSI values from the same safety helmet within a preset aggregation time window. It then generates an aggregated data packet containing aggregated data, a sequence number, and a timestamp before broadcasting it.
[0064] At least one relay gateway is deployed between the location gateway and the public network gateway to extend network coverage and overcome physical obstructions and distance limitations. The relay gateway uses the same 2.4G communication chip as the location gateway and is configured for low-power operation. Depending on network size and environmental complexity, the relay gateway can be configured as a single-level or multi-level cascaded system to receive and forward aggregated data packets broadcast by the location gateway. The public network gateway, with a built-in 2.4G communication core and Ethernet interface (or 4G Cat.1 module), is deployed in areas with stable network access, such as project offices and monitoring centers. The public network gateway receives aggregated data packets forwarded by the last-level relay gateway and uploads the data to a cloud platform or host computer via an external network (Ethernet, 4G / 5G, WiFi, etc.).
[0065] This invention's positioning gateway continuously scans and receives 2.4G wireless data packets broadcast by multiple positioning helmets within its coverage area. For each received valid data packet, the positioning gateway first measures its Received Signal Strength Indication (RSSI) value, which reflects the distance relationship between the positioning helmet and the positioning gateway. Within a preset aggregation time window (e.g., 5 seconds), the positioning gateway will receive multiple data packets from the same positioning helmet, thus obtaining multiple RSSI measurements. If the positioning helmet is in motion mode, it broadcasts 5 times per second, up to 25 data packets within 5 seconds. Uploading all raw data packets would cause a huge network load.
[0066] Therefore, at the end of each aggregation time window, the positioning gateway aggregates multiple RSSI values from the same positioning helmet, retaining only the RSSI value with the highest signal strength as the feature value for that time window. This maximum-value aggregation method has the following advantages: it greatly reduces the amount of data, compressing dozens of original data packets into one aggregated data packet; it retains effective information, as the maximum RSSI value in positioning calculations usually corresponds to the most reliable signal path; and it has strong anti-interference capabilities, filtering out weak signals caused by transient interference and retaining the strongest signal.
[0067] After aggregation, the positioning gateway encapsulates the extracted feature values, along with the corresponding safety helmet's identification information (ID), serial number (auto-incrementing serial number), and timestamp (time stamp) indicating the end of the current aggregation time window, into a single aggregated data packet. To improve the reception success rate of downstream gateways, the positioning gateway repeatedly broadcasts this aggregated data packet multiple times (e.g., three times consecutively). This method significantly increases the probability of successful reception at least once in environments with signal interference or momentary obstruction.
[0068] Relay gateways are crucial for resolving the conflict between long-distance transmission and battery power in complex environments. To address this conflict, relay gateways employ the following self-learning synchronization mechanism: After the relay gateway is powered on, it first enters the listening mode. By receiving multiple aggregated data packets broadcast by the upstream gateway, it analyzes the arrival time pattern of each data packet and autonomously learns to establish a wake-up schedule that is synchronized with the sending time of the upstream gateway. After synchronization is established, the relay gateway switches to intermittent working mode, only waking up and opening the receiving window at the time corresponding to the wake-up schedule, and remaining in sleep mode at other times. After successfully receiving the aggregated data packet from the upstream gateway within the receiving window, the relay gateway updates the data packet and forwards it to the downstream gateway within the subsequent sending window.
[0069] The specific implementation of analyzing the arrival time patterns of each data packet and autonomously learning to establish a wake-up schedule synchronized with the upstream gateway's transmission timing is as follows: The relay gateway's radio frequency unit is continuously turned on, constantly listening to the wireless channel and recording all parseable data packets and their precise reception times. By continuously listening to multiple data packets from its upstream gateway (for a first-level relay gateway, the upstream is the positioning gateway), the following operations are performed: Based on the reception timestamps of consecutive data packets, the data transmission period T (e.g., 5 seconds) of the upstream gateway is calculated; when the calculated data transmission period T tends to stabilize (when the calculated data transmission period T remains constant for multiple consecutive times (e.g., 3-5 times) or fluctuates slightly near its average, it is determined to be tending to stabilize), the next reception time is determined as the transmission start time reference T0; based on T0 and T, all future data transmission time points of the upstream gateway are predicted using the formula Tn = T0 + n * T, generating a data transmission time sequence (i.e., wake-up schedule) T′={T0,..., T0 + n * T}.
[0070] After learning is complete, the relay gateway automatically switches to a low-power operating mode. In this mode, during periods not corresponding to the data transmission time sequence, the relay gateway shuts down the RF module, the CPU enters deep sleep mode, and power consumption drops to the microampere level. Hundreds of microseconds before each predicted data transmission time point, the relay gateway is woken up by an RTC timer and the RF module is turned on. It then opens a listening window (e.g., lasting 800 milliseconds) aligned with the upstream gateway's broadcast time window, within which it receives the aggregated data packets broadcast by the upstream gateway.
[0071] After receiving the data, the relay gateway processes the aggregated data packet, incrementing the relay level field value within the packet by at least 1 to indicate the number of relays the packet has passed through. Then, within a preset broadcast time window, it forwards the processed aggregated data packet to the downstream gateway. After broadcasting, it immediately re-enters deep sleep mode, awaiting the next wake-up cycle.
[0072] Through the aforementioned "listen-learn-synchronize" mechanism, the relay gateway achieves multi-hop data transmission with extremely low power consumption. Within a 5-second cycle, the relay gateway only wakes up for a few hundred milliseconds within its working window, remaining in sleep mode for the rest of the time. Its average power consumption is extremely low, allowing for long-term operation under battery power.
[0073] This invention defines relay gateways as levels 1 to N according to data flow order, where N is an integer greater than or equal to 1. The upstream gateway of a level 1 relay gateway is a location gateway, and the downstream gateway of a level N relay gateway is a public network gateway. The upstream gateway of a level k relay gateway is a level (k-1) relay gateway, and the downstream gateway is a level (k+1) relay gateway, where k is an integer from 2 to N-1. A level 1 relay gateway automatically identifies itself as a first-level node by listening to the broadcast signal of the location gateway. A level k relay gateway confirms its position in the network by identifying the relay level field value as k-1 in the received data packets. A level N relay gateway identifies itself as a last-level node by recognizing that its forwarded data packets will be received by the public network gateway. Levels 1 through N and above operate by receiving data packets from upstream gateways, learning and entering a low-power mode, and then converting and sending the data packets to downstream gateways. The entire network forms a cascading sleep-wake-listen-broadcast workflow.
[0074] This embodiment uses a construction site with signal coverage dead zones as an example, and deploys as follows: Figure 3 The positioning system shown.
[0075] In this embodiment, the system composition and initial state are as follows.
[0076] Positioning safety helmets: worn by different construction workers, for example, construction worker 1 wears positioning safety helmet 1, and construction worker 2 wears positioning safety helmet 2. Each positioning safety helmet broadcasts a 2.4G wireless signal at a high frequency (e.g., 10 times per second), and its frame structure contains its globally unique ID number.
[0077] Location gateway: Deployed in the central area of the construction site. It uses a system-on-a-chip (SoC) that integrates a 2.4G radio frequency and a processor, such as Nordic Semiconductor's nRF52840.
[0078] Relay gateways: Level 1 relay gateways are deployed at the edge of areas where the location gateway signal is weak. Level 2 relay gateways are deployed on the path leading to the project site to bridge the signal. Their hardware is the same as the location gateway to reduce costs. Level 3 relay gateways are deployed in areas where the signal needs to be further extended, such as when there is physical obstruction or an extremely long distance between the Level 2 relay gateway and the public network gateway, to achieve the final relay of the signal.
[0079] Public network gateway: Deployed in the project office with a stable wired network, with the same 2.4G communication core and Ethernet interface (or 4G Cat.1 module) built in.
[0080] Finally, it should be noted that the above embodiments are merely preferred embodiments of the present invention used to illustrate the technical solutions of the present invention, and are not intended to limit the invention, nor are they intended to limit the patent scope of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. That is to say, any changes or refinements made to the main design concept and spirit of the present invention that are not of substantial significance, but whose technical problems are still consistent with the present invention, should be included within the protection scope of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention to other related technical fields are similarly included within the patent protection scope of the present invention.
Claims
1. A low-power, recharge-free personnel positioning safety helmet based on 2.4G, characterized in that: include: The helmet itself; The positioning tag is fixed to the helmet body; Location tags include: A 2.4G wireless transceiver circuit is used to broadcast 2.4G wireless data packets containing unique identification information of the location tag; An accelerometer is used to collect motion data of the wearer. Disposable batteries provide power for the positioning tags; The main control unit is electrically connected to the 2.4G wireless transceiver circuit and the accelerometer. Based on the motion state data output by the accelerometer, the main control unit determines whether the wearer's motion state is in motion mode or stationary mode. Based on the determined motion state, the main control unit dynamically adjusts the broadcast frequency of the 2.4G wireless transceiver circuit. The broadcast frequency in motion mode is higher than that in stationary mode.
2. The low-power, recharge-free personnel positioning safety helmet based on 2.4G as described in claim 1, characterized in that, Determining the wearer's movement status specifically includes: When the positioning tag is in stationary mode, the main control unit periodically acquires motion state data collected by the accelerometer at a first acquisition interval and sets a first count value to record the number of times motion state is detected consecutively. Each acquired data point is compared with a preset motion threshold. If the data exceeds the threshold, the first count value is incremented; otherwise, the first count value is cleared. When the first count value reaches the first preset value, the main control unit determines that the wearer has entered a movement state and switches the positioning tag to movement mode; When the positioning tag is in motion, the main control unit periodically acquires motion state data collected by the accelerometer at a second acquisition interval, and sets a second count value to record the number of times a stationary state is detected consecutively. Each acquired data point is compared with a preset motion threshold. If the motion threshold is not exceeded, the second count value is incremented; otherwise, the second count value is cleared. When the second count value reaches the second preset value, the main control unit determines that the wearer has entered a stationary state and switches the positioning tag to stationary mode.
3. The low-power, recharge-free personnel positioning safety helmet based on 2.4G as described in claim 1, characterized in that, The location tag indicates whether it's in factory default or activation mode: In factory default mode, the 2.4G wireless transceiver circuit broadcasts at the first broadcast frequency; In active mode, the main control unit broadcasts at a dynamically adjusted frequency based on the wearer's movement.
4. The low-power, recharge-free personnel positioning safety helmet based on 2.4G as described in claim 1, characterized in that, The broadcast frequency is 5 times per second in sports mode and 1 time per second in stationary mode.
5. The low-power, recharge-free personnel positioning safety helmet based on 2.4G as described in claim 1, characterized in that, The positioning tag also includes a waterproof device and an anti-tamper device, with the waterproof device covering the outside of the positioning tag; preferably, the anti-tamper device is a push-button anti-tamper micro switch.
6. The low-power, recharge-free personnel positioning safety helmet based on 2.4G as described in claim 1, characterized in that, The disposable battery is a 2000mAh lithium manganese battery, and the overall weight of the positioning tag is less than or equal to 35 grams. The positioning tag is fixed to the helmet body with high-viscosity adhesive.
7. The low-power, recharge-free personnel positioning safety helmet based on 2.4G as described in claim 1, characterized in that, The location tag also includes a buzzer and LED status indicators connected to the main control unit.
8. A positioning system, characterized in that, include: Multiple positioning safety helmets as described in any one of claims 1-7; At least one positioning gateway is used to receive 2.4G wireless data packets broadcast by the positioning safety helmet, measure the RSSI value of each wireless data packet, and aggregate multiple RSSI values from the same positioning safety helmet within a preset aggregation time window to generate an aggregated data packet containing aggregated data, serial number and time identifier before broadcasting it. At least one relay gateway is required to receive and forward aggregated data packets broadcast by the location gateway. The public network gateway is used to receive aggregated data packets forwarded by the last-level relay gateway and upload them to the cloud platform or host computer via the external network.
9. The positioning system according to claim 8, characterized in that, The relay gateway has a self-learning synchronization mechanism: After the relay gateway is powered on, it first enters the listening mode. By receiving multiple aggregated data packets broadcast by the upstream gateway, it analyzes the arrival time pattern of each data packet and autonomously learns to establish a wake-up schedule that is synchronized with the sending time of the upstream gateway. After synchronization is established, the relay gateway switches to intermittent working mode, only waking up and opening the receiving window at the time corresponding to the wake-up schedule, and remaining in sleep mode at other times. After successfully receiving the aggregated data packet from the upstream gateway within the receiving window, the relay gateway updates the data packet and forwards it to the downstream gateway within the subsequent sending window.
10. The positioning system according to claim 9, characterized in that, At the end of each aggregation time window, the positioning gateway extracts the feature values from multiple RSSI values from the same positioning helmet, encapsulates them together with the corresponding positioning helmet's identification information and time identifier into an aggregated data packet, and broadcasts the aggregated data packet repeatedly a preset number of times. When receiving aggregated data packets, the relay gateway filters out duplicate data packets based on the sequence number in the data packet and forwards only the first valid data packet received.