Trajectory tracking method and device of unpowered trailer, computer equipment and storage medium

Abstract

The invention provides a trajectory tracking method and device, computer equipment and a storage medium, and belongs to the field of unpowered trailer resource management.The trajectory tracking method specifically comprises the steps that gateway data collected by a mobile gateway on a tractor in real time are obtained; according to the timestamp and the signal intensity value in the gateway data, drawing a discrete point diagram formed by each beacon identifier; determining the real-time relative position of the unpowered trailer and the tractor based on the discrete point diagram, and grouping the tractor and the unpowered trailer according to the real-time relative position; generating a real-time running track of the unpowered trailer according to the marshalling information and the running track of the tractor, and acquiring a data packet sent by the same Bluetooth beacon in real time to judge that the received signal intensity value is obviously changed; marshalling is cancelled, and the unpowered trailer is positioned again according to gateway data collected by the mobile gateway on the tractor in real time. Through the processing scheme of the invention, autonomous and accurate identification of the track of the unpowered trailer is realized.

Description

Technical Field

[0001] This application relates to the field of non-powered trailer resource management, and in particular to a method, apparatus, computer equipment, and storage medium for tracking the trajectory of a non-powered trailer. Background Technology

[0002] In civil aviation airport ground support operations, airlines, ground service companies, and airports share unpowered trailers. These trailers move frequently across multiple areas, including terminals, aprons, and cargo areas, necessitating their location tracking and management. However, the shared nature and high mobility of these trailers among multiple units in airport ground operations leads to unclear maintenance responsibilities and potential disputes arising from damage. Manual management suffers from high labor costs, untimely inventory checks, and a high risk of errors. Furthermore, it's impossible to quickly track trailer usage. Even when using RFID, GNSS satellite positioning, or UWB / RTLS methods for trailer management, GNSS active navigation solutions are costly and power-hungry, and are easily obstructed in hangars and terminal areas. Real-time tracking of unpowered trailers is also impossible, hindering real-time monitoring of their use. Summary of the Invention

[0003] Therefore, in order to overcome the shortcomings of the prior art, the present invention provides a method, device, computer equipment, and storage medium for tracking the trajectory of a non-powered trailer by fusing signal strength data of the tractor and the trailer to achieve autonomous and accurate identification of the trajectory of the non-powered trailer.

[0004] To achieve the above objectives, the present invention provides a trajectory tracking method for a non-powered trailer, comprising: acquiring gateway data collected in real time by a mobile gateway on a tractor, wherein the gateway data includes at least multiple beacon identifiers, corresponding timestamps, and signal strength values ​​of Bluetooth beacon broadcasts received from the non-powered trailer; drawing a discrete point map composed of each beacon identifier based on the timestamps and signal strength values ​​in the gateway data; determining the real-time relative position of the non-powered trailer and the tractor based on the discrete point map, and grouping the tractor and the non-powered trailer according to the real-time relative position; generating a real-time running trajectory of the non-powered trailer based on the grouping information and the running trajectory of the tractor; and, when a significant change in the received signal strength value is determined by real-time acquisition of data packets sent by the same Bluetooth beacon, canceling the grouping and repositioning the non-powered trailer according to the gateway data collected in real time by the mobile gateway on the tractor.

[0005] In one embodiment, determining the real-time relative position of the unpowered trailer and the tractor based on the discrete point map includes: smoothing the scatter points of the same beacon identifier in the discrete point map through a sliding window and obtaining the average signal strength corresponding to the beacon identifier; drawing the real-time mapping curve corresponding to the beacon identifier of each Bluetooth beacon; and determining the real-time relative position of the unpowered trailer and the tractor based on the real-time mapping curve.

[0006] In one embodiment, grouping the tractor and the unpowered trailer according to the real-time relative position includes: determining the vehicle order of the unpowered trailer after the tractor based on the real-time relative position; and grouping the tractor and the unpowered trailer according to the vehicle order when the vehicle order of the unpowered trailer after the tractor remains unchanged for a predetermined time.

[0007] In one embodiment, when the signal strength value of the received data packets sent by the same Bluetooth beacon changes significantly during real-time acquisition, the ungrouping is cancelled and the unpowered trailer is repositioned based on the gateway data collected in real-time by the mobile gateway on the tractor. This includes: drawing a discrete point map corresponding to the timestamps based on the timestamps and signal strength values ​​in the different gateway data collected from the same Bluetooth beacon; determining that the tractor and the unpowered trailer containing the Bluetooth beacon have separated when the rate of change of the signal strength value of adjacent timestamps exceeds a predetermined threshold and the number of data packets received by the mobile gateway on the tractor within a fixed time period is lower than a predetermined threshold; cancelling the grouping of the unpowered trailer and the tractor based on the separation determination result; and repositioning the unpowered trailer based on the data packets collected in real-time by the mobile gateway on the tractor.

[0008] In one embodiment, the step of repositioning the unpowered trailer based on gateway data collected in real time by the mobile gateway on the tractor includes: when the mobile gateway of the tractor collects data packets of the same Bluetooth beacon again in real time within a predetermined time range, obtaining the signal strength value of the mobile gateway when it collects the data packet and determining the average signal strength before the tractor and the unpowered trailer containing the Bluetooth beacon separated; when the rate of change between the signal strength value and the average signal strength does not exceed the predetermined threshold, determining that the vehicle order of the unpowered trailer after the tractor remains unchanged, and regrouping the tractor and the unpowered trailer according to the vehicle order.

[0009] In one embodiment, generating the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor includes: determining the binding time and unbinding time of the unpowered trailer and the tractor based on the grouping information; and generating the real-time running trajectory of the unpowered trailer based on the binding time, the unbinding time, and the running trajectory of the tractor.

[0010] A trajectory tracking method for a non-powered trailer includes: real-time broadcasting of data packets from Bluetooth beacons mounted on the non-powered trailer, the data packets containing at least a beacon identifier of the Bluetooth beacon; real-time acquisition of data packets broadcast from at least one Bluetooth beacon on a tractor unit, and generation of gateway data, the gateway data containing the beacon identifier of at least one received Bluetooth beacon, a corresponding timestamp, and a signal strength value; receiving gateway data fed back by at least one of the mobile gateways, the gateway data carrying a gateway identifier and all the received data packets; plotting a discrete point map of each beacon identifier corresponding to the gateway identifier based on the timestamp and signal strength value in the gateway data; determining the real-time relative position of the non-powered trailer and the tractor unit based on the discrete point map, and grouping the tractor unit and the non-powered trailer according to the real-time relative position; generating a real-time running trajectory of the non-powered trailer based on the grouping information and the running trajectory of the tractor unit, and canceling the grouping and repositioning the non-powered trailer according to the real-time acquired gateway data when the real-time relative position of the non-powered trailer and the tractor unit changes significantly.

[0011] A trajectory tracking device for a non-powered trailer, the device comprising: a data acquisition module for acquiring gateway data collected in real time by a mobile gateway on a tractor, the gateway data including at least multiple beacon identifiers, corresponding timestamps, and signal strength values ​​of Bluetooth beacon broadcasts received from the non-powered trailer; a dot plotting module for plotting a discrete dot plot composed of each beacon identifier based on the timestamps and signal strength values ​​in the data packets; a position grouping module for determining the real-time relative position of the non-powered trailer and the tractor based on the discrete dot plot, and grouping the tractor and the non-powered trailer according to the real-time relative position; and a trajectory generation module for generating the real-time running trajectory of the non-powered trailer based on the grouping information and the running trajectory of the tractor, and when a significant change in the received signal strength value is determined from data packets transmitted by the same Bluetooth beacon in real time, canceling the grouping and repositioning the non-powered trailer based on the gateway data collected in real time by the mobile gateway on the tractor.

[0012] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the above-described method.

[0013] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0014] Compared with the prior art, the advantages of the present invention are as follows: by analyzing the timestamp and signal strength value of the data packets of Bluetooth beacon broadcast from the unpowered trailer collected in real time by the mobile gateway, the spatiotemporal relationship between the tractor and the unpowered trailer is determined, the cooperative movement path of the trailer and the tractor is accurately identified, and the dynamic binding relationship is determined and the movement trajectory of the unpowered trailer is accurately analyzed, thereby facilitating the subsequent management and allocation of unpowered trailer resources. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic flowchart of a trajectory tracking method for a non-powered trailer in one embodiment of the present invention; Figure 2 This is a discrete point diagram corresponding to each beacon identifier in one embodiment of the present invention; Figure 3 This is a flowchart illustrating the real-time relative position positioning steps in one embodiment of the present invention; Figure 4 This is a real-time mapping curve diagram corresponding to each beacon identifier in one embodiment of the present invention; Figure 5 This is a flowchart illustrating a trajectory tracking method for a non-powered trailer in another embodiment of the present invention. Figure 6 This is a structural block diagram of a trajectory tracking device for a non-powered trailer in one embodiment of the present invention; Figure 7 This is an internal structural diagram of a computer device according to one embodiment of the present invention. Detailed Implementation

[0017] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0018] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that the following description covers various aspects of embodiments within the scope of protection of this invention. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0020] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0022] This application provides a trajectory tracking method for a non-powered trailer, which can be applied to a server or terminal. The terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, and portable smart devices. The server can be a standalone server or a server cluster composed of multiple servers. Figure 1 As shown, the method is applied to a server as an example, and includes the following steps: Step 101: Obtain gateway data collected in real time by the mobile gateway on the tractor. The gateway data includes at least multiple beacon identifiers, corresponding timestamps, and signal strength values ​​of Bluetooth beacon broadcasts received from the unpowered trailer.

[0023] Non-powered trailers can be used in airports as various flatbed trucks, boxcars, and other small vehicles for transporting luggage and cargo. Each non-powered trailer is equipped with a Bluetooth beacon that can broadcast signals periodically, with a transmission distance of 10-50 meters. The Bluetooth signal can carry the beacon's identifier. The broadcast interval range of the Bluetooth beacon can be set according to actual needs; for example, the broadcast interval T... m = 1 s, the signal transmission frequency is 0.1 s / time, the sleep duty cycle is 10%, the power consumption current is <10 μA, and the transmission current is 10mA. Therefore, the average power consumption of the Bluetooth beacon per transmission is ≈ transmission power consumption × 10% + sleep power consumption × 90% = 1mA + 9μA ≈ 1mA (mainly consumed in transmission). Thus, the Bluetooth beacon has low power consumption; even a regular button battery can maintain its working life for 5-8 years. The cost of the Bluetooth beacon can be controlled within 100 yuan, which is conducive to large-scale promotion.

[0024] Bluetooth beacons can also be fixed to non-powered trailers to passively sense the trailer's movement and then obtain different broadcast states based on the trailer's movement. For example, in stationary mode, the broadcast interval T... s = 5 s, each signal transmission duration is 0.1 s, sleep duty cycle is 2%, power consumption current < 2 μA. In motion mode, the broadcast interval T m = 1 s, each signal transmission duration is 0.1 s, sleep duty cycle is 10%, power consumption current <10 μA. Under this condition, Bluetooth beacon vibration sensing can achieve near-zero static power consumption motion state determination using a mechanically filtered vibration sensing structure and a passive delay-hold circuit. The passive delay-hold circuit provides a control gating signal for the vibration-triggered electrical signal. For example, the passive delay-hold circuit uses a combination of a unidirectional diode + energy storage capacitor + high-impedance resistor to form a delay time constant τ≈100 ms–300 ms holding time, ensuring that continuous vibration signals receive a sufficiently high gating signal while occasional vibrations are filtered out. During Bluetooth beacon broadcasting, the beacon identifier and motion status of the Bluetooth beacon on the unpowered trailer can be broadcast in real time via data packets.

[0025] A mobile gateway is installed on the tractor unit. The mobile gateway can be powered by the tractor unit's onboard power supply and / or a combination of solar panels. The mobile gateway (vehicle-mounted Bluetooth gateway) continuously scans for surrounding Bluetooth beacons. Since stationary trailer beacons broadcast every 5 seconds in this mode, and amplify their transmission power to cover a distance of over 80 meters, and the tractor unit traverses the beacon coverage area for approximately 25 seconds, at least 5 RSSI readings for the same beacon can be captured. The mobile gateway's control system records at least the timestamp of the received Bluetooth signal and the corresponding signal strength value (RSSI value). In one embodiment, the mobile gateway's control system can simultaneously record the gateway's GPS coordinates (1–3 m positioning accuracy), the timestamp of the received Bluetooth signal, and the corresponding signal strength value (RSSI value) for each scan, providing a spatiotemporally corresponding dataset for subsequent positioning. The mobile gateway can upload data packets from all Bluetooth beacons acquired in real time to a server. The mobile gateway can utilize UWB, GPS / BeiDou, WIFI, or base stations for positioning. A mobile gateway or server can estimate distance or determine relative position using the received Bluetooth beacon signal strength index (RSSI value). (Bluetooth signals weaken with distance, so the signal strength value of the same Bluetooth beacon collected at different distances will vary.) For example, the mobile gateway or server can first store the distance-signal strength attenuation curve of the Bluetooth signal, and then determine the position of the unpowered trailer based on this curve. Alternatively, the mobile gateway can sort all the collected Bluetooth beacon signal strength values ​​according to their strength to determine the relative positions between different unpowered trailers.

[0026] The server can be a physical server or a cloud server. The server can receive and acquire gateway data collected in real time by the mobile gateway on the tractor. The gateway data includes at least the beacon identifiers of multiple received Bluetooth beacon broadcasts, the timestamps of the corresponding beacon identifier reception times, and the signal strength values ​​collected by the gateway when the Bluetooth signal is received.

[0027] Step 102: Draw a discrete point map composed of each beacon identifier based on the timestamp and signal strength value in the gateway data.

[0028] The server draws a discrete point map composed of beacon identifiers based on the timestamps and signal strength values ​​in the gateway data. For example... Figure 2 As shown, the server can plot a discrete point graph consisting of each beacon identifier, with time as the x-axis and the Bluetooth beacon signal strength value (RSSI value) as the y-axis. Figure 2 The non-powered trailers in the picture are boxcars. The beacon symbol for boxcar 1 is indicated by a circle, the beacon symbol for boxcar 2 is indicated by a square, and the beacon symbol for boxcar 3 is indicated by a triangle. Figure 2Cart 1, cart 2, and cart 3 move away from the gateway in sequence. The average signal strength distribution of cart 1, cart 2, and cart 3 during operation is -55dBm, -63dBm, and -73dBm, respectively.

[0029] Step 103: Determine the real-time relative position of the unpowered trailer and the tractor based on the discrete point map, and group the tractor and the unpowered trailer according to the real-time relative position.

[0030] The server determines the real-time relative position of the unpowered trailer and the tractor unit based on a discrete point map, and groups the tractor unit and unpowered trailer according to this real-time relative position. The server can directly determine the real-time relative position of the unpowered trailer and the tractor unit based on the signal strength values ​​of the Bluetooth beacons on the unpowered trailer and the signal strength loss pattern with distance, or it can draw a line graph for further analysis to determine the real-time relative position and group the tractor unit and unpowered trailer according to this real-time relative position. The server can determine whether the unpowered trailer is bound to the tractor unit based on all real-time relative positions of the same tractor unit within a predetermined period, and determine whether there is a distance conflict between different unpowered trailers. When there is no distance conflict between different unpowered trailers, the server groups the tractor unit and unpowered trailer. Figure 2 Boxcar 1, Boxcar 2, and Boxcar 3 are moved away from the gateway in sequence. Therefore, the server can group the tractor and Boxcar 1, Boxcar 2, and Boxcar 3 together and store the time period of the grouping for subsequent trajectory tracking.

[0031] Step 104: Generate the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor. When the received signal strength value changes significantly when the data packets sent by the same Bluetooth beacon are collected in real time, cancel the grouping and reposition the unpowered trailer based on the gateway data collected in real time by the mobile gateway on the tractor.

[0032] The server generates the real-time trajectory of the unpowered trailer based on the grouping time period and the tractor's running trajectory in the grouping information. The tractor's running trajectory can be collected through its own navigation system. Alternatively, it can be generated in real-time by locating and tracking the tractor via UWB, GPS / BeiDou, WIFI, or base stations. The server can generate the real-time trajectory of the unpowered trailer based on the tractor's running trajectory and grouping information. Figure 2 As shown, the server can also detect significant changes in the signal strength value carried by data packets from the same Bluetooth beacon during real-time acquisition (e.g., Figure 2 (The signal strength value of boxcar 3 disappeared at 13:28). The server can cancel the grouping of boxcar 3 and reposition the unpowered trailer based on the gateway data collected in real time by the mobile gateway on the tractor (e.g., Figure 2The signal strength of car 3 recovered at 13:34, at which point the server re-included car 3 into the group.

[0033] The above method analyzes the timestamps and signal strength values ​​of data packets broadcast by Bluetooth beacons from the unpowered trailer in real time, collected by the mobile gateway, to determine the spatiotemporal relationship between the tractor and the unpowered trailer, accurately identify the cooperative movement path of the trailer and the tractor, realize the dynamic binding relationship determination and the accurate analysis of the movement trajectory of the unpowered trailer, thereby facilitating the subsequent management and allocation of unpowered trailer resources.

[0034] In one embodiment, determining the real-time relative position of the unpowered trailer and the tractor based on a discrete point map includes the following steps: Step 301: Smooth the values ​​of the scattered points of the same beacon in the discrete point map by using a sliding window, and obtain the average signal strength corresponding to the beacon.

[0035] The server uses a sliding window to smooth the values ​​of scattered points for the same beacon identifier in the discrete point graph and obtains the average signal strength (RSSI) corresponding to that beacon identifier. avg (value), such as Figure 2 The values ​​are -55, -63, and -73 dBm, etc. The server uses a sliding window average algorithm with a window width of (1s-10s) to obtain the RSSI of the beacon ID at a certain moment. avg The server obtains the signal strength values ​​of all scattered points within the sliding window and calculates the average to obtain the RSSI. avg value.

[0036] In one embodiment, the server can also perform short-term jitter removal on the acquired raw RSSI value sequence. For example, if the motion state of a beacon is continuously less than 2 seconds, it is considered a scanning jitter and discarded. Subsequently, the median of the RSSI readings of the same beacon is filtered to remove outliers that deviate from the median value by ±6 dB, so as to reduce the impact of multipath effects and sudden interference. The server then aggregates 3-5 valid readings of the same Bluetooth beacon during the passage of the inspection vehicle into a stable RSSI window sequence, laying the foundation for subsequent accurate positioning.

[0037] Step 302: Plot the real-time mapping curve corresponding to the beacon identifier of each Bluetooth beacon.

[0038] The server uses the average signal strength (RSSI) avg (Value) Establish a real-time mapping curve between vehicle signal fingerprint and signal strength ( Figure 4 The duration of the sliding window can be selected from 1 second to 10 seconds. Figure 4 The top curve represents boxcar 1, the middle curve represents boxcar 2, and the bottom curve represents boxcar 3.

[0039] Step 303: Determine the real-time relative position of the unpowered trailer and the tractor based on the real-time mapping curve.

[0040] The server can extract the RSSI value reflecting the actual distance from the real-time mapping curve and determine the real-time relative position of the unpowered trailer and the tractor. For example, the server can determine the value around which the real-time mapping curve fluctuates, and then determine that value as the RSSI value corresponding to that real-time mapping curve, thereby determining the real-time relative position of the unpowered trailer and the tractor.

[0041] The above method can accurately determine the real-time relative position of the unpowered trailer and avoid the effects of multipath effects and sudden disturbances.

[0042] In one embodiment, grouping the tractor and the unpowered trailer according to the real-time relative position includes: determining the vehicle order of the unpowered trailer after the tractor based on the real-time relative position; and grouping the tractor and the unpowered trailer according to the vehicle order when the vehicle order of the unpowered trailer after the tractor remains unchanged for a predetermined time.

[0043] The server can preliminarily determine the vehicle order of unpowered trailers following motorized trains based on real-time relative positions (1m-30m). For example, the server can automatically bind a group of beacon IDs that meet the criteria of "stable RSSI mean and small variance" into the same "accompanying group" and automatically perform relationship binding.

[0044] In one embodiment, the server can also compare the RSSI values ​​of different unpowered trailers with the RSSI value. avg The server will further verify whether different non-powered trailers conform to the vehicle sorting criteria based on the changes in the values. If the criteria are met and the vehicle sorting of the non-powered trailers after the tractor remains unchanged within the predetermined time, the server will group the tractor and the non-powered trailers according to the vehicle sorting criteria.

[0045] If the order of unpowered trailers following the towing vehicle remains unchanged within a predetermined time period, the server will group the towing vehicle and the unpowered trailers according to their vehicle order. For example, for each beacon, samples with RSSI > -85 dBm within the most recent K (3-5) windows are extracted, and their moving average signal strength value RSSI is calculated. avg Within N consecutive windows, compare the RSSI with the RSSI each time. avg The difference ΔRSSI (this value is the absolute value) must satisfy 0 < ΔRSSI < 8 dB; when the above condition is met, record the binding start time T. startIf it is successful, the "binding" event will be triggered; otherwise, the unbound state will remain, and data caching and judgment will continue.

[0046] In one embodiment, the server calculates the average signal strength (RSSI) of each candidate beacon over four consecutive sliding windows. avg The server compares the signals based on the average signal strength (RSSI) collected by each mobile gateway when the same Bluetooth beacon is collected by multiple mobile gateways. avg Sort the data according to the RSSI of a certain gateway. avg If the beacon consistently exceeds the suboptimal gateway by at least 6 dB, it is determined that the beacon and the gateway vehicle have formed a "stable bond," and the bond time T is immediately recorded. start .

[0047] The above method further accurately determines the grouping of non-powered trailers and avoids mutual interference between grouped vehicles traveling in parallel for a short period of time.

[0048] In one embodiment, when the signal strength value of the received data packets sent by the same Bluetooth beacon changes significantly during real-time acquisition, the unpowered trailer is disengaged and repositioned based on the gateway data collected in real-time by the mobile gateway on the tractor. This includes: plotting a discrete point map corresponding to the timestamps based on the timestamps and signal strength values ​​in the different gateway data collected from the same Bluetooth beacon; determining that the tractor and the unpowered trailer containing the Bluetooth beacon have detached when the rate of change of signal strength values ​​between adjacent timestamps exceeds a predetermined threshold and the number of data packets received by the mobile gateway on the tractor within a fixed time period is lower than a predetermined threshold; based on the detachment determination result, disengaging the unpowered trailer from the tractor; and repositioning the unpowered trailer based on the data packets collected in real-time by the mobile gateway on the tractor.

[0049] The server plots a discrete point graph corresponding to the timestamps based on the timestamps and signal strength values ​​collected from different gateways for the same Bluetooth beacon, such as... Figure 2 Scatter plot of boxcar 3 in the image.

[0050] When the rate of change of signal strength values ​​between adjacent timestamps exceeds a predetermined threshold and the number of data packets received by the mobile gateway on the tractor unit within a fixed time period is lower than a predetermined threshold, the server determines that the tractor unit and the unpowered trailer containing the Bluetooth beacon have become detached. When the rate of change of signal strength values ​​between adjacent timestamps exceeds the threshold and is accompanied by packet loss (the mobile gateway on the tractor unit fails to receive data packets from the Bluetooth beacon, i.e., the number of data packets received by the tractor unit within a fixed time period is lower than a predetermined threshold), the server automatically triggers a "detachment" alarm (corresponding to...). Figure 4 (The uncoupling point of the boxcar 3). Specifically, when the RSSI of the boxcar 3 Bluetooth beacon... avgIf the value drops below -90 dBm, or if the continuous static state lasts for more than 30 seconds, the server determines it as an "unbinding event" and records the unbinding time T. end Subsequently, by using the GPS trajectory of the tractor and the dead reckoning algorithm driven by the beacon RSSI to fuse and compensate for the trajectory of the unpowered trailer, the positioning error can be kept within 5 meters even in satellite signal blind spots.

[0051] Based on the detachment determination result, the server cancels the grouping of the unpowered trailer and the tractor. The server also cancels the grouping of boxcar 3 and the tractor containing the mobile gateway.

[0052] The server repositions the unpowered trailer based on gateway data collected in real time by the mobile gateway on the tractor.

[0053] The above method can update the binding status of the non-powered trailer based on the real-time collected gateway data, thereby enabling the tracking of the non-powered trailer's trajectory.

[0054] In one embodiment, the non-powered trailer is repositioned based on gateway data collected in real time by the mobile gateway on the tractor vehicle, including: when the mobile gateway of the tractor vehicle collects data packets of the same Bluetooth beacon again in real time within a predetermined time range, obtaining the signal strength value when the mobile gateway collects the data packet and determining the average signal strength before the tractor vehicle and the non-powered trailer where the Bluetooth beacon are located separated; when the rate of change between the signal strength value and the average signal strength does not exceed a predetermined threshold, determining that the vehicle order of the non-powered trailer behind the tractor vehicle remains unchanged, and regrouping the tractor vehicle and the non-powered trailer according to the vehicle order.

[0055] When the mobile gateway of the tractor unit collects data packets from the same Bluetooth beacon again within a predetermined time range, the server obtains the signal strength value when the mobile gateway collected the data packet and the average signal strength value before the tractor unit and the unpowered trailer containing the Bluetooth beacon separated. When a beacon's RSSI reappears after a period of loss (corresponding to...) Figure 4 When the boxcar 3 reappears in the middle, the server will not only check the current strength, but also retrieve the "last known strength fingerprint" before the disconnection.

[0056] When the rate of change between the signal strength value and the average signal strength value does not exceed a predetermined threshold, it is determined that the vehicle order of the unpowered trailer after the tractor remains unchanged, and the tractor and unpowered trailer are regrouped according to the vehicle order. The server determines the RSSI after reconnection. avg The value quickly returned to its previous stable range. Figure 4 (The value is around -73dBm). The server automatically restores the original sequence number in the group, without the need for manual intervention to re-number.

[0057] The above method achieves automatic identification and binding of the following status of the unpowered trailer based on the stability characteristics of the RSSI signal strength generated by the relatively stable movement of the tractor and the unpowered trailer.

[0058] In one embodiment, generating the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor includes: determining the binding and unbinding times of the unpowered trailer and the tractor based on the grouping information; and generating the real-time running trajectory of the unpowered trailer based on the binding and unbinding times and the running trajectory of the tractor.

[0059] The server determines the binding time T between the unpowered trailer and the tractor based on the grouping information. start And the moment of unbinding T end The server generates the real-time trajectory of the unpowered trailer based on the binding and unbinding times and the tractor's trajectory.

[0060] In one embodiment, such as Figure 5 As shown, a trajectory tracking method for a non-powered trailer is provided, including the following steps: Step 501: The Bluetooth beacon set on the non-powered trailer broadcasts a data packet in real time, the data packet containing at least the beacon identifier of the Bluetooth beacon.

[0061] The data packet can contain not only the beacon identifier of the Bluetooth beacon, but also the motion status of the non-powered trailer corresponding to the Bluetooth beacon (moving=1, stationary=0), battery level warning (normal=0, low=1), checksum (used to verify the completeness of information), reserved fields (which can be used for extended purposes, such as temperature, environment, etc.).

[0062] Step 502: The mobile gateway on the tractor collects data packets from at least one Bluetooth beacon broadcast from the unpowered trailer in real time and generates gateway data. The gateway data includes at least the beacon identifiers of multiple received Bluetooth beacon broadcasts from the unpowered trailer, the corresponding timestamps, and the signal strength values.

[0063] A mobile gateway on the tractor unit collects data packets from at least one Bluetooth beacon broadcast from a non-powered trailer in real time. The mobile gateway packages all the collected Bluetooth beacon data packets into gateway data. The gateway data includes at least the beacon identifiers of the received Bluetooth beacon broadcasts, the timestamps of the corresponding beacon identifier reception times, and the signal strength value collected by the gateway when the Bluetooth signal was received.

[0064] Step 503: The server receives gateway data from at least one mobile gateway. The gateway data carries the gateway identifier and all received data packets.

[0065] The server receives gateway data from at least one mobile gateway. This gateway data carries the gateway identifier and all received data packets. The gateway data may also carry the location information of the tractor unit and the gateway timestamp from when the data was uploaded.

[0066] Step 504: The server draws a discrete point map consisting of each beacon identifier corresponding to the gateway identifier based on the timestamp and signal strength value in the gateway data.

[0067] Step 505: The server determines the real-time relative position of the unpowered trailer and the tractor based on the discrete point map, and groups the tractor and the unpowered trailer according to the real-time relative position.

[0068] Step 506: The server generates the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor. When the real-time relative position of the unpowered trailer and the tractor changes significantly, the grouping is canceled and the unpowered trailer is repositioned based on the real-time collected gateway data.

[0069] In one embodiment, such as Figure 6 As shown, a trajectory tracking device for a non-powered trailer is also provided. The device includes a data acquisition module 601, a dot plotting module 602, a position grouping module 603, and a trajectory generation module 604.

[0070] The data acquisition module 601 is used to acquire gateway data collected in real time by the mobile gateway on the tractor. The gateway data includes at least multiple beacon identifiers, corresponding timestamps, and signal strength values ​​of Bluetooth beacon broadcasts received from the unpowered trailer.

[0071] The dot plot drawing module 602 is used to draw a discrete dot plot composed of each beacon identifier based on the timestamp and signal strength value in the gateway data.

[0072] The position grouping module 603 is used to determine the real-time relative position of the unpowered trailer and the tractor based on a discrete point map, and to group the tractor and the unpowered trailer according to the real-time relative position.

[0073] The trajectory generation module 604 is used to generate the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor. When the received signal strength value changes significantly when the data packets sent by the same Bluetooth beacon are collected in real time, the grouping is canceled and the unpowered trailer is repositioned based on the gateway data collected in real time by the mobile gateway on the tractor.

[0074] In one embodiment, the location grouping module includes: The averaging unit is used to smooth the values ​​of scattered points with the same beacon identifier in the discrete point graph through a sliding window, and obtain the average signal strength corresponding to the beacon identifier.

[0075] The curve plotting unit is used to plot the real-time mapping curve corresponding to the beacon identifier of each Bluetooth beacon.

[0076] The position determination unit is used to determine the real-time relative position of the unpowered trailer and the tractor based on the real-time mapping curve.

[0077] In one embodiment, the location grouping module includes: The sorting unit is used to determine the order of vehicles behind the tractor unit for the unpowered trailer based on their real-time relative positions.

[0078] The grouping unit is used to group the tractor and the non-powered trailer according to the vehicle order when the order of the non-powered trailers behind the tractor remains unchanged within a predetermined time.

[0079] In one embodiment, the trajectory generation module includes: The scatter plot generation unit is used to draw a discrete plot corresponding to the timestamp based on the timestamp and signal strength values ​​in different gateway data collected from the same Bluetooth beacon.

[0080] The separation determination unit is used to determine that the tractor and the unpowered trailer where the Bluetooth beacon is located have separated when the rate of change of the signal strength value of adjacent timestamps exceeds a predetermined threshold and the number of data packets received by the mobile gateway on the tractor within a fixed time period is less than a predetermined threshold.

[0081] The group cancellation unit is used to cancel the grouping of unpowered trailers and tractors based on the determination of disengagement.

[0082] The positioning unit is used to reposition the unpowered trailer based on data packets collected in real time by the mobile gateway on the tractor.

[0083] In one embodiment, the trajectory generation module includes: The re-evaluation unit is used to obtain the signal strength value of the mobile gateway when it collects the data packet of the same Bluetooth beacon again in real time within a predetermined time range, and to determine the average signal strength value before the tractor and the unpowered trailer where the Bluetooth beacon are located separated.

[0084] The regrouping unit is used to determine that the vehicle order of the unpowered trailer after the tractor remains unchanged when the rate of change between the signal strength value and the average signal strength does not exceed a predetermined threshold, and to regroup the tractor and the unpowered trailer according to the vehicle order.

[0085] In one embodiment, the trajectory generation module includes: The timing unit is used to determine the binding and unbinding times of the unpowered trailer and tractor based on the grouping information.

[0086] The trajectory generation unit is used to generate the real-time running trajectory of the unpowered trailer based on the binding and unbinding times and the running trajectory of the tractor.

[0087] Specific limitations regarding the trajectory tracking device for non-powered trailers can be found in the limitations of the trajectory tracking method for non-powered trailers mentioned above, and will not be repeated here. Each module in the aforementioned trajectory tracking device for non-powered trailers can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0088] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 7 As shown, the computer device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores gateway data, Bluetooth data packets, and other data. The network interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a trajectory tracking method for a non-powered trailer.

[0089] In one embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to perform the following steps: acquiring gateway data collected in real time by a mobile gateway on a tractor, the gateway data including at least multiple beacon identifiers, corresponding timestamps, and signal strength values ​​of Bluetooth beacon broadcasts received from unpowered trailers; drawing a discrete point map composed of each beacon identifier based on the timestamps and signal strength values ​​in the gateway data; determining the real-time relative position of the unpowered trailer and the tractor based on the discrete point map, and grouping the tractor and the unpowered trailer according to the real-time relative position; generating a real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor, and when it is determined that the received signal strength value has changed significantly when data packets sent by the same Bluetooth beacon are collected in real time, canceling the grouping and repositioning the unpowered trailer according to the gateway data collected in real time by the mobile gateway on the tractor.

[0090] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When executed by a processor, the computer program performs the following steps: acquiring gateway data collected in real time by a mobile gateway on a tractor, the gateway data including at least multiple beacon identifiers, corresponding timestamps, and signal strength values ​​of Bluetooth beacon broadcasts received from unpowered trailers; drawing a discrete point map composed of each beacon identifier based on the timestamps and signal strength values ​​in the data packets; determining the real-time relative position of the unpowered trailer and the tractor based on the discrete point map, and grouping the tractor and the unpowered trailer according to the real-time relative position; generating the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor, and when it is determined that the received signal strength value has changed significantly when data packets sent by the same Bluetooth beacon are collected in real time, canceling the grouping and repositioning the unpowered trailer according to the gateway data collected in real time by the mobile gateway on the tractor.

[0091] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A trajectory tracking method for a non-powered trailer, characterized in that, include: The gateway data collected in real time by the mobile gateway on the tractor is obtained. The gateway data includes at least multiple beacon identifiers, corresponding timestamps, and signal strength values ​​of Bluetooth beacon broadcasts received from the unpowered trailer. A discrete point map composed of each beacon identifier is drawn based on the timestamp and signal strength value in the gateway data; The real-time relative position of the unpowered trailer and the tractor is determined based on the discrete point map, and the tractor and the unpowered trailer are grouped according to the real-time relative position. The real-time running trajectory of the unpowered trailer is generated based on the grouping information and the running trajectory of the tractor. When the received signal strength value changes significantly when the data packets sent by the same Bluetooth beacon are collected in real time, the grouping is canceled and the unpowered trailer is repositioned based on the gateway data collected in real time by the mobile gateway on the tractor.

2. The trajectory tracking method according to claim 1, characterized in that, Determining the real-time relative position between the unpowered trailer and the tractor based on the discrete point map includes: The values ​​of the scattered points of the same beacon identifier in the discrete point map are smoothed by using a sliding window, and the average signal strength corresponding to the beacon identifier is obtained. Plot the real-time mapping curves corresponding to the beacon identifiers of each Bluetooth beacon; The real-time relative position of the unpowered trailer and the tractor is determined based on the real-time mapping curve.

3. The trajectory tracking method according to claim 1, characterized in that, The step of grouping the tractor and the unpowered trailer according to the real-time relative position includes: The order of the unpowered trailers following the tractor is determined based on the real-time relative positions. If the order of the unpowered trailers following the tractor remains unchanged within a predetermined time, the tractor and the unpowered trailers will be grouped according to the vehicle order.

4. The trajectory tracking method according to claim 1, characterized in that, When the received signal strength value changes significantly after real-time acquisition of data packets sent by the same Bluetooth beacon, the unpowered trailer is disbanded and repositioned based on the gateway data collected in real-time by the mobile gateway on the tractor, including: Plot a discrete point graph corresponding to the timestamp based on the timestamps and signal strength values ​​collected from different gateways for the same Bluetooth beacon. When the rate of change of signal strength values ​​between adjacent timestamps exceeds a predetermined threshold and the number of data packets received by the mobile gateway on the tractor within a fixed time period is less than a predetermined threshold, it is determined that the tractor and the unpowered trailer where the Bluetooth beacon is located have detached. Based on the determination of detachment, the formation of non-powered trailers and tractors will be cancelled. The unpowered trailer is repositioned based on data packets collected in real time by the mobile gateway on the tractor.

5. The trajectory tracking method according to claim 4, characterized in that, The step of repositioning the unpowered trailer based on gateway data collected in real time by the mobile gateway on the tractor includes: When the mobile gateway of the tractor unit collects the data packet of the same Bluetooth beacon again in real time within a predetermined time range, the signal strength value of the mobile gateway when it collects the data packet and the average signal strength value of the tractor unit and the unpowered trailer where the Bluetooth beacon is located before they separate are obtained. When the rate of change between the signal strength value and the average signal strength does not exceed the predetermined threshold, it is determined that the vehicle order of the unpowered trailer after the tractor remains unchanged, and the tractor and the unpowered trailer are regrouped according to the vehicle order.

6. The trajectory tracking method according to claim 1, characterized in that, The step of generating the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor includes: The binding and unbinding times of the unpowered trailer and the tractor are determined based on the grouping information. The real-time running trajectory of the unpowered trailer is generated based on the binding and unbinding times and the running trajectory of the tractor.

7. A trajectory tracking method for a non-powered trailer, characterized in that, include: A Bluetooth beacon mounted on a non-powered trailer broadcasts data packets in real time, the data packets containing at least the beacon identifier of the Bluetooth beacon; The mobile gateway on the tractor unit collects data packets from at least one Bluetooth beacon broadcast from the unpowered trailer in real time and generates gateway data, which includes at least the beacon identifiers, corresponding timestamps, and signal strength values ​​of the multiple received Bluetooth beacon broadcasts from the unpowered trailer. The server receives gateway data fed back by at least one of the mobile gateways, the gateway data carrying a gateway identifier and all the data packets received; The server draws a discrete point map consisting of each beacon identifier, corresponding to the gateway identifier, based on the timestamp and signal strength value in the gateway data; The server determines the real-time relative position of the unpowered trailer and the tractor based on the discrete point map, and groups the tractor and the unpowered trailer according to the real-time relative position. The server generates the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor. When the real-time relative position of the unpowered trailer and the tractor changes significantly, the grouping is canceled and the unpowered trailer is repositioned based on the real-time collected gateway data.

8. A trajectory tracking device for a non-powered trailer, characterized in that, The device includes: The data acquisition module is used to acquire gateway data collected in real time by the mobile gateway on the tractor. The gateway data includes at least multiple beacon identifiers, corresponding timestamps, and signal strength values ​​of Bluetooth beacon broadcasts received from the unpowered trailer. The dot plot drawing module is used to draw a discrete dot plot composed of each beacon identifier based on the timestamp and signal strength value in the gateway data; The position grouping module is used to determine the real-time relative position of the unpowered trailer and the tractor based on the discrete point map, and to group the tractor and the unpowered trailer according to the real-time relative position. The trajectory generation module is used to generate the real-time running trajectory of the unpowered trailer based on the grouping information and the running trajectory of the tractor. When the received signal strength value is significantly changed by the data packets sent by the same Bluetooth beacon in real time, the grouping is canceled and the unpowered trailer is repositioned based on the real-time collected gateway data.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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