433MHz two-way anti-collision work card and vehicle-mounted receiving device

Abstract

The application discloses a 433MHz bidirectional anti-collision work card and a vehicle-mounted receiving device. The anti-collision work card is composed of a first radio frequency transceiver module, a 433MHz omnidirectional antenna, a loudspeaker and a vibration motor, etc. The vehicle-mounted receiving device is composed of a second radio frequency transceiver module, a 433MHz receiving antenna, a vehicle-mounted warning component and a voltage stabilizing module, etc. The vehicle-mounted receiving device determines the relative position range based on the received signal strength of the received work card broadcast frame, triggers the local alarm and sends an instruction frame to the work card. The work card drives the loudspeaker and the vibration motor to alarm synchronously in response to the instruction frame. The application completes the edge local alarm closed loop in the weak network or network interruption scene, avoids the problem that the whole cloud architecture is invalid in the weak network, and can roughly determine the relative vehicle direction of the personnel based on the time sequence change trend of the received signal strength through a single omnidirectional antenna, which significantly reduces the hardware cost compared with the multiple directional antenna scheme.

Description

Technical Field

[0001] This invention relates to the field of wireless radio frequency communication and personnel safety protection technology, specifically to a work badge and vehicle-mounted receiving device that realizes two-way approach warning for vehicles and personnel based on 433MHz Received Signal Strength Intensity (RSSI). Background Technology

[0002] In mining areas, ports, material yards, and large construction sites, heavy-duty vehicles are generally tall with large blind spots in the driver's cab. Drivers are very likely to miss workers passing by these vehicles, leading to collisions or run-over accidents. Dust and low-light environments further reduce the effective visual distance.

[0003] Existing anti-collision wearable devices for this scenario mainly employ ultra-wideband (UWB) based personnel tags and vehicle-mounted base stations, or satellite-based personnel positioning terminals. The former has higher module costs and higher standby power consumption for personnel-side tags; the latter suffers from signal loss in scenarios such as underground mines or material piles where signals are obstructed.

[0004] Another known solution involves installing multiple directional antennas and radio frequency receivers at the front, rear, and right side of a heavy vehicle. Each directional antenna determines the direction of approach of personnel and calculates the distance between the vehicle and personnel based on RSSI. The driver then receives an audible, visual, and voice warning from a cab-mounted warning device (this solution is known in the art). However, this solution requires installing multiple receivers and directional antennas on the same vehicle, resulting in high hardware costs and complex installation. Another known solution involves uploading the radio frequency signal from the personnel-side tag to a cloud server, where the server performs distance calculations and sends warning commands to the vehicle-side alarm device (this solution is known in the art). This solution fails entirely in weak network or network outage scenarios, and the alarm link has a long latency. Summary of the Invention

[0005] To overcome the above shortcomings, the purpose of this invention is to provide a 433MHz bidirectional anti-collision badge and vehicle-mounted receiving device, which enables vehicles and personnel to directly complete distance classification and synchronous alarm based on the 433MHz received signal strength broadcast on the badge locally on the vehicle, and can make a rough judgment of the personnel's position relative to the vehicle without having to deploy multiple directional antenna receivers on the same vehicle.

[0006] The technical problems to be solved by this invention are: ① to complete the local vehicle-person distance determination and alarm closed loop at the edge in weak network or network outage scenarios; ② to form graded alarms with gradient differences so that drivers and personnel can receive increasingly stronger prompts at different distances; ③ to realize bidirectional synchronous alarm between work badges and vehicle-mounted devices; ④ to roughly determine the location of personnel under the condition of a single omnidirectional antenna.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides a 433MHz two-way collision avoidance warning system, including a collision avoidance badge and a vehicle-mounted receiving device. The collision avoidance badge includes a wearable shell, a microcontroller unit disposed within the shell, a first radio frequency transceiver module connected to the microcontroller unit, a 433MHz omnidirectional antenna connected to the first radio frequency transceiver module, a speaker unit, a vibration motor unit, and a rechargeable battery connected to the microcontroller unit. The microcontroller unit is used to drive the first radio frequency transceiver module to broadcast a 433MHz broadcast frame containing the badge identifier at a preset broadcast period. The vehicle-mounted receiving device includes a vehicle housing, a microprocessor disposed within the housing, and a device connected to the microprocessor. The system includes a second radio frequency transceiver module, a 433MHz receiving antenna connected to the second radio frequency transceiver module, an on-board alarm device connected to the microprocessor, and a voltage regulator module connected to the vehicle power supply. The microprocessor is configured to: determine the relative position level of the crash barrier based on the received signal strength of the received broadcast frame locally on the on-board receiver; trigger a local alarm via the on-board alarm device in response to the relative position level; and send a command frame back to the crash barrier via the second radio frequency transceiver module. The microcontroller unit of the crash barrier is further configured to drive the horn unit and the vibration motor unit to output alarms synchronously in response to the command frame.

[0008] The present invention is further configured such that the microprocessor is equipped with at least three preset threshold levels corresponding to different relative distances, and a hysteresis interval is provided between adjacent threshold levels; the microprocessor is further configured with a continuous N-frame crossing confirmation mechanism, wherein the relative position is set to the threshold level only when the received signal strength of N consecutively received broadcast frames all exceed the same threshold level and the duration is not less than the preset minimum dwell time of the threshold level, wherein N is not less than 2.

[0009] The present invention is further configured such that the microprocessor, based on the temporal variation trend of the received signal strength of multiple broadcast frames received within a first time window, roughly determines the position of the anti-collision sign relative to the vehicle where the vehicle-mounted receiving device is located, and outputs the roughly determined position to the driver via the vehicle-mounted alarm device. The position includes at least three categories: front, rear, and side. When the received signal strength monotonically increases within the first time window and the rate of increase is not less than a first rate threshold, it is roughly determined to be in front; when it monotonically decreases and the rate of decrease is not less than a second rate threshold, it is roughly determined to be in rear; and when the statistical variance of the received signal strength is not less than a preset variance threshold, it is roughly determined to be in side.

[0010] The present invention is further configured such that, in the standby state when the anti-collision sign does not receive the instruction frame, the microcontroller broadcasts at a first broadcast frequency, and when the received signal strength of the received instruction frame or the locally received broadcast frame from the vehicle-mounted receiver is not lower than the warning threshold, the microcontroller switches to a second broadcast frequency, and the second broadcast frequency is higher than the first broadcast frequency.

[0011] The present invention is further configured such that both the first RF transceiver module and the second RF transceiver module operate in the 431~446.5 MHz frequency band, with a transmit power of not less than 10 dBm; the 433MHz omnidirectional antenna and the first RF transceiver module, as well as the 433MHz receiving antenna and the second RF transceiver module, are impedance matched with 50Ω; the horn unit and the vibration motor unit are respectively connected in parallel to the microcontroller unit through independent pulse width modulation output pins; the center distance between the 433MHz omnidirectional antenna and the horn unit is not less than 5 mm, and the center distance between the 433MHz omnidirectional antenna and the vibration motor unit is not less than 8 mm.

[0012] The present invention is further configured such that the vehicle-mounted receiving device independently maintains the current relative position level, the sliding window of the most recently received signal strength, and the azimuth estimate for multiple different work badges, and determines the priority of the local alarm in the order of relative position level from near to far and the number of consecutive crossing frames from most to least; when there are multiple work badges with the same relative position level and the same alarm priority, the azimuth roughly determined by each work badge is broadcast separately, or the azimuths are combined into one broadcast and output to the driver.

[0013] Compared with the prior art, the beneficial effects of the present invention are: First, the alarm decision is completed locally on the vehicle-mounted receiving device without relying on the cloud server, enabling the invention to still work normally in weak network or network outage scenarios. The alarm link latency is reduced to the millisecond level, avoiding the problem of known cloud architectures failing as a whole in weak network conditions.

[0014] Secondly, the vehicle-mounted receiver and the anti-collision badge form a two-way synchronous alarm closed loop through the same radio frequency link, so that both the badge and the vehicle receive alarms at the same time; the badge side outputs alarms in parallel through a horn and a vibration motor, so that personnel can perceive the alarm through skin touch even in noisy mining environments, avoiding accidents caused by alarm failure at either end.

[0015] Third, the temporal variation trend of the received signal strength based on multiple broadcast frames can roughly determine the location of people relative to the vehicle when there is only a single omnidirectional antenna. Compared with known solutions that require multiple directional antenna receivers to be deployed on the front and rear sides of the vehicle, the hardware cost and construction workload are significantly reduced.

[0016] Fourth, the work badge operates at the first broadcast frequency when in standby mode and switches to a higher second broadcast frequency when it is close to the next broadcast frequency. This allows the work badge to maintain a low power consumption state most of the time, significantly extending the standby battery life compared to a fixed-period broadcast scheme.

[0017] Fifth, the vehicle-mounted receiving device actively controls the output of the alarm device on the work badge side via a command frame, so that the horn and vibration motor of the work badge can be driven synchronously with the vehicle-mounted alarm device, thereby improving the alarm perception of personnel in the driver's blind spot. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall architecture of the 433MHz bidirectional collision avoidance warning system of the present invention; Figure 2 This is a schematic diagram of the internal structure of the anti-collision badge of the present invention; Figure 3 This is a schematic diagram of the internal structure of the vehicle-mounted receiving device of the present invention; Figure 4 This is a timing diagram of the bidirectional synchronous alarm chain of the present invention; Figure 5 This is a schematic diagram illustrating the principle of coarse orientation determination based on RSSI time-series change trends in this invention.

[0019] Reference numerals: 1. Anti-collision badge; 2. Vehicle-mounted receiver; 10. Microcontroller unit; 11. First RF transceiver module; 12. 433MHz omnidirectional antenna; 13. Speaker unit; 13A. Audio amplifier; 14. Vibration motor unit; 15. Rechargeable lithium battery; 16. Button unit; 17. Magnetic charging interface; 18. Status indicator (badge); 20. Microprocessor; 21. Second RF transceiver module; 22. 433MHz receiving antenna; 23. Vehicle-mounted speaker driver unit; 24. Voltage regulator module; 25. Status indicator (vehicle-mounted); 26. Vehicle power interface; 27. Magnetic mounting bracket. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments; the following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention.

[0021] Example 1: System Overall Architecture like Figure 1As shown, the 433MHz bidirectional collision avoidance warning system of the present invention consists of a collision avoidance badge (1) and a vehicle-mounted receiver (2). The collision avoidance badge (1) is worn by the operator; the vehicle-mounted receiver (2) is installed in the cab or front of the mining truck, loader, or other large working vehicle. The two communicate bidirectionally via a 433MHz frequency band wireless link. The badge shell is preferably about 110×62×12.5 mm in size, weighs about 86.7 g, and has a waterproof rating of IP66.

[0022] like Figure 1 and Figure 2 As shown, the anti-collision badge (1) integrates a microcontroller unit (10), a first radio frequency transceiver module (11), a 433MHz omnidirectional antenna (12), a speaker unit (13), a vibration motor unit (14), a rechargeable lithium battery (15), a button unit (16), a magnetic charging interface (17), and a status indicator (18). In this embodiment, the first radio frequency transceiver module (11) uses a CC1101 chip, operates in the frequency band of 431~446.5 MHz, has a transmit power of 10 dBm, and a typical receive sensitivity of no more than -107dBm. The 433MHz omnidirectional antenna (12) is a rubber whip or a PCB-mounted antenna, connected to the antenna pin of the first radio frequency transceiver module (11) through a 50Ω impedance matching link. The speaker unit (13) is connected in parallel to the microcontroller unit (10) through an audio power amplifier (13A) and the vibration motor unit (14) through independent pulse width modulation output pins, so that both can be driven simultaneously. The rechargeable lithium battery (15) has a capacity of not less than 2000 mAh and is charged at 5V / 1A via the magnetic charging interface (17).

[0023] like Figure 1 and Figure 3 As shown, the vehicle-mounted receiver (2) integrates a microprocessor (20), a second radio frequency transceiver module (21), a 433MHz receiving antenna (22), a vehicle horn driver unit (23), a voltage regulator module (24), a status indicator (25), and a vehicle power interface (26). In this embodiment, the second radio frequency transceiver module (21) uses a CC1101 chip and is connected to the microprocessor (20) via an SPI interface; the 433MHz receiving antenna (22) is connected to the antenna pin of the second radio frequency transceiver module (21) via a 50Ω impedance matching link. The back of the vehicle housing of the vehicle-mounted receiver (2) is further provided with a magnetic mounting base or screw hole mounting structure (27) for easy installation on the dashboard or roof of the driver's cab. The input end of the voltage regulator module (24) is connected to the vehicle power supply (input voltage range 9~30 VDC) via the vehicle power interface (26), and the output end provides a stable 3.3 VDC power supply to the microprocessor (20) and the second radio frequency transceiver module (21).

[0024] Example 2: Broadcast Frame Structure and Broadcast Strategy The microcontroller unit (10) of the anti-collision badge (1) drives the first radio frequency transceiver module (11) to transmit a 433MHz broadcast frame via a 433MHz omnidirectional antenna (12) at a preset period (step S1). The broadcast frame includes a preamble, synchronization word, badge identifier, power field, status field, timestamp, and CRC check. When the badge (1) does not receive the instruction frame sent back by the vehicle-mounted receiver (2) and the received signal strength of the broadcast frame from the vehicle-mounted receiver (2) is lower than the warning threshold, it transmits the broadcast frame at the first broadcast frequency; when it receives the instruction frame or the received signal strength of the broadcast frame from the vehicle-mounted receiver (2) is not lower than the warning threshold, it switches to the second broadcast frequency to transmit the broadcast frame, and the second broadcast frequency is higher than the first broadcast frequency. In this embodiment, the first broadcast frequency is preferably not greater than 2 Hz and the second broadcast frequency is preferably not less than 5 Hz.

[0025] Example 3: Vehicle-mounted receiver for distance determination and bidirectional alarm chain like Figure 4 As shown, after the work badge broadcast frame arrives, the vehicle-mounted receiving device (2) reads the received signal strength of the frame from the received signal strength register of the second radio frequency transceiver module (21) (step S2), and the microprocessor (20) maintains at least three preset threshold levels (step S3), corresponding to the long-range warning level (S4-P), the medium-range alarm level (S4-M), and the short-range emergency level (S4-E), respectively. Each threshold level is calibrated on-site according to the vehicle model and the height of the device antenna before installation.

[0026] The microprocessor (20) performs a continuous N-frame over-limit confirmation on the received signal strength (step S3A): an alarm for that level is triggered only when the received signal strength of the N consecutively received broadcast frames all exceed the threshold of the same level and the duration is not less than the preset minimum dwell time of that level; a hysteresis interval is provided between levels to make it less likely for the received signal strength jitter at the critical distance to cause frequent level jumps (step S6). In this embodiment, N is preferably 3 to 5, and the hysteresis interval is preferably not less than 3 dB.

[0027] Once a certain gear is determined, the vehicle receiver (2) triggers the local horn to output an alarm sound according to the corresponding gear through the vehicle horn drive unit (23) (long-distance warning with a slow sound + voice "person ahead", medium-distance warning with a medium-speed sound + "please slow down", and close-range emergency with a rapid sound + "emergency avoidance"); on the other hand, it sends a command frame back to the work badge (1) through the second radio frequency transceiver module (21). The command frame contains the target work badge identifier and the alarm gear identifier; the work badge (1) responds to the command frame (step S5), and the micro control unit (10) drives the horn unit (13) and the vibration motor unit (14) to output alarms synchronously according to the corresponding gear, so that the alarm on the work badge side and the alarm on the vehicle side are consistent in rhythm and intensity.

[0028] The microprocessor (20) of the vehicle-mounted receiver (2) independently maintains the current gear, the nearest received signal strength sliding window, and the direction estimation for multiple different work badges, and determines the alarm priority in the order of "high gear - many consecutive crossing frames - strong received signal strength". When there are multiple people located in front of and to the side of the vehicle (or other different directions) at the same time, and the relative positions of each person are at the same gear, and the alarm priorities obtained in the above order are also the same, the microprocessor (20) broadcasts the alarm for each direction separately, or combines the alarms for each direction into a single broadcast message and outputs it to the driver (for example, broadcasting "people in front and to the right" at the same time); when the directions of each person are different and their received signal strengths are different, the alarms are broadcast in order of receiving signal strength from strong to weak, so that the driver can be aware of the person on the closer side first, thereby avoiding missed alarms when multiple people of the same priority are present in the same direction.

[0029] Example 4: Coarse azimuth determination based on the temporal variation trend of received signal strength like Figure 5 As shown, the microprocessor (20) of the vehicle-mounted receiver (2) further performs timing analysis on the received signal strength of the received multi-frame broadcast frames within the first time window. When the vehicle is in motion, the vehicle speed is read by the vehicle-mounted receiver (2) via OBD, CAN or vehicle-mounted GNSS module as a judgment condition.

[0030] Scenario 1: When a vehicle approaches a stationary person at a speed v along the current direction of travel, and the name tag remains in the area in front of the vehicle, the on-board receiver performs linear regression on the received signal strength of multiple frames within the first time window of 0.5 to 1 second to obtain a positive slope (i.e., the received signal strength increases monotonically with time). Based on this, the microprocessor determines that the person is in the area in front of the vehicle's direction of travel and broadcasts "There is a person ahead" to the driver. Scenario 2: After the vehicle has passed the stationary person, the on-board receiver performs linear regression on the received signal strength of multiple frames within the first time window of 0.5 to 1 second to obtain a negative slope (i.e., the received signal strength decreases monotonically with time). Based on this, the microprocessor determines that the person is located in the area behind the vehicle's direction of movement. Scenario 3: When a vehicle is traveling at a constant speed v along the current direction of travel, and a person is located to the side of the vehicle (left or right) and the distance between them and the vehicle remains basically unchanged, the received signal strength of multiple frames does not have a significant monotonic trend in the first time window and has a large statistical variance (the variance is not less than 5 dB² in typical scenarios). Based on this, the microprocessor determines that the person is located to the side of the vehicle. The above-mentioned preliminary location judgment results are broadcast to the driver by the vehicle-mounted warning device, so that the driver can make an avoidance decision by referring to the rearview mirror or the vehicle-mounted camera.

[0031] Example 5: Antenna Avoidance Arrangement like Figure 2 As shown, the center-to-center distance between the 433MHz omnidirectional antenna (12) and the horn unit (13) in the workplate (1) is not less than 5mm, and the center-to-center distance between the 433MHz omnidirectional antenna (12) and the vibration motor unit (14) is not less than 8mm, in order to reduce the coupling loss between the RF antenna and the audio / vibration module. When the workplate (1) is further integrated with the 4G communication module and the Global Navigation Satellite System (GNSS) module, the center-to-center distance between the 433MHz omnidirectional antenna (12) and the antenna of the 4G communication module is not less than 15mm, and the center-to-center distance between the 433MHz omnidirectional antenna (12) and the antenna of the GNSS module is not less than 20mm, and a grounding isolation strip is provided on the PCB board.

[0032] Example 6: Proactively relinquishing public knowledge technology statements In specific implementations, the first and second RF transceiver modules can employ Sub-1GHz RF transceiver chips known in the art, such as the CC1101 series. Their register configuration, SPI interface timing, automatic gain control (AGC), and idle channel assessment (CCA) mechanisms can employ any known method described in the corresponding chip manufacturer's publicly available manual. The conversion relationship between received signal strength and distance can be implemented using known methods in the art, such as the logarithmic path loss model. The specific numerical implementation of linear regression and variance determination in the coarse forward / backward / lateral azimuth determination can employ any known linear regression method and variance calculation method in the embedded control field. The aforementioned known technologies do not constitute the inventive point of this invention but are merely optional implementation methods for carrying out this invention.

[0033] The above embodiments are only used to illustrate the present invention and do not limit the scope of protection of the present invention. The technical features in each embodiment can be combined with each other, and when the combination does not contradict each other, it should be considered as the scope of the description in this specification.

Claims

1. A 433 MHz bi-directional collision warning system characterized in that, The system includes a crash barrier badge (1) and a vehicle-mounted receiver (2). The crash barrier badge (1) includes a wearable shell, a microcontroller unit (10) located inside the shell, a first radio frequency transceiver module (11) connected to the microcontroller unit (10), a 433MHz omnidirectional antenna (12) connected to the first radio frequency transceiver module (11), a speaker unit (13), a vibration motor unit (14), and a rechargeable battery (15) connected to the microcontroller unit (10). The microcontroller unit (10) is used to drive the first radio frequency transceiver module (11) to broadcast a 433MHz broadcast frame containing the badge identifier at a preset broadcast period. The vehicle-mounted receiver (2) includes a vehicle housing, a microprocessor (20) located inside the vehicle housing, and a second radio frequency transceiver unit connected to the microprocessor (20). The system includes a transmitter module (21), a 433MHz receiving antenna (22) connected to the second radio frequency transceiver module (21), an on-board alarm device (23) connected to the microprocessor (20), and a voltage regulator module (24) connected to the vehicle power supply. The microprocessor (20) is used to: determine the relative position of the vehicle receiving device (2) with respect to the crash barrier (1) based on the received signal strength of the received broadcast frame, trigger a local alarm via the on-board alarm device (23) in response to the relative position, and send a command frame back to the crash barrier (1) via the second radio frequency transceiver module (21). The microcontroller unit (10) of the crash barrier (1) is further used to drive the horn unit (13) and the vibration motor unit (14) to output alarms synchronously in response to the command frame.

2. The 433MHz bidirectional collision avoidance warning system according to claim 1, characterized in that: The microprocessor (20) is configured with at least three preset threshold levels corresponding to different relative distances, and a hysteresis interval is provided between adjacent threshold levels so that the relative position level does not jump when the received signal strength fluctuates slightly; the microprocessor (20) is further configured with a continuous N-frame crossing confirmation mechanism, and the microprocessor (20) will set the relative position level to the threshold level only when the received signal strength of the N consecutively received broadcast frames all exceeds the same threshold level and the duration is not less than the preset minimum dwell time of the level level, where N is not less than 2.

3. The 433MHz bidirectional collision avoidance warning system according to claim 1, characterized in that: The microprocessor (20) is further used to roughly determine the position of the anti-collision sign (1) relative to the vehicle where the vehicle-mounted receiving device (2) is located based on the temporal variation trend of the received signal strength of the multiple broadcast frames received within the first time window, and output the roughly determined position to the driver via the vehicle-mounted alarm device (23); the position includes at least three categories: front, rear and side.

4. The 433MHz bidirectional collision avoidance warning system according to claim 3, characterized in that: The determination of the timing change trend includes: when the received signal strength of the broadcast frame increases monotonically within the first time window and the rate of increase is not less than the first rate threshold, the microprocessor (20) roughly determines the direction as forward; when the received signal strength decreases monotonically within the first time window and the rate of decrease is not less than the second rate threshold, the microprocessor (20) roughly determines the direction as backward; when the statistical variance of the received signal strength within the first time window is not less than the preset variance threshold, the microprocessor (20) roughly determines the direction as sideways.

5. The 433MHz bidirectional collision avoidance warning system according to claim 1, characterized in that: The microcontroller unit (10) is used to drive the first radio frequency transceiver module (11) to broadcast at the first broadcast frequency when the anti-collision badge (1) is in standby mode and does not receive the instruction frame; when the received signal strength of the broadcast frame received by the vehicle receiving device (2) is not lower than the warning threshold, it switches to broadcast at the second broadcast frequency, and the second broadcast frequency is higher than the first broadcast frequency.

6. The 433MHz bidirectional collision avoidance warning system according to claim 1, characterized in that: The first radio frequency transceiver module (11) and the second radio frequency transceiver module (21) both operate in the 431~446.5 MHz frequency band and have a transmission power of not less than 10dBm; the 433MHz omnidirectional antenna (12) and the first radio frequency transceiver module (11) and the 433MHz receiving antenna (22) and the second radio frequency transceiver module (21) are both 50Ω impedance matched; the horn unit (13) and the vibration motor unit (14) are respectively connected in parallel to the microcontroller unit (10) through independent pulse width modulation output pins; the center distance between the 433MHz omnidirectional antenna (12) and the horn unit (13) in the anti-collision work sign (1) is not less than 5 mm, and the center distance between the horn unit (13) and the vibration motor unit (14) is not less than 8 mm.

7. The 433MHz bidirectional collision avoidance warning system according to claim 1, characterized in that: The vehicle-mounted receiving device (2) is used to independently maintain the current relative position level, the sliding window of the most recently received signal strength and the azimuth estimation for multiple different work badges, and to determine the priority of the local alarm in the order of relative position level from near to far and the number of consecutive cross-line frames from most to least. When there are multiple work badges with the same relative position level and the same alarm priority, the vehicle-mounted receiving device (2) broadcasts the azimuth roughly determined by each work badge separately, or merges the azimuth into a single broadcast and outputs it to the driver.

8. A collision avoidance warning method based on the 433MHz bidirectional collision avoidance warning system of claim 1, characterized in that, include: S1. The anti-collision badge (1) broadcasts a 433MHz broadcast frame containing the badge identifier to the outside according to a preset broadcast cycle; S2. The vehicle-mounted receiver (2) receives the broadcast frame, extracts the received signal strength of the broadcast frame, and determines the relative position level of the anti-collision badge (1) locally based on the received signal strength; S3. When the relative position level is determined to change, the vehicle-mounted receiver (2) triggers a local alarm through the vehicle-mounted alarm device (23) and sends a command frame back to the anti-collision badge (1) through the second radio frequency transceiver module (21); S4. The anti-collision badge (1) responds to the command frame by driving the horn unit (13) and the vibration motor unit (14) to output alarm synchronously.

9. The collision avoidance warning method according to claim 8, characterized in that: Step S2 further includes roughly determining the position of the anti-collision sign (1) relative to the vehicle based on the temporal change trend of the received signal strength of multiple broadcast frames received within the first time window, and step S3 further includes broadcasting the roughly determined position to the driver via the vehicle-mounted alarm device (23); step S1 further includes the anti-collision sign (1) broadcasting at a first broadcast frequency in a standby state when it has not received the instruction frame, and switching to a second broadcast frequency when it receives the instruction frame or when the received signal strength of the broadcast frame received locally by the vehicle-mounted receiving device (2) is not lower than the warning threshold, wherein the second broadcast frequency is higher than the first broadcast frequency.

10. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the collision avoidance warning method as described in claim 8 or claim 9.

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