Remote communication method and system of unmanned mine car

Abstract

The invention discloses a remote communication method and system for an unmanned mine car, and belongs to the field of communication.The remote communication method for the unmanned mine car comprises the following steps that a three-dimensional terrain model of a mine area is constructed, and electromagnetic wave propagation path loss is calculated in real time; if it is predicted that the communication quality of the target unmanned mine car is possibly lower than a threshold value due to terrain shielding after the dynamic time threshold value T, a direct communication mode is changed into an intermediate communication mode; screening relay nodes from other unmanned mine cars; compared with the prior art, the method has the advantages that the communication mode is changed in advance by judging whether the communication quality of the unmanned mine car is lower than the threshold value possibly due to terrain shielding or not in advance, the direct communication mode is changed into the intermediate communication mode, and after it is confirmed that the terrain shielding risk is relieved and the communication quality is judged, the communication mode is changed into the intermediate communication mode. An intermediate communication mode is changed into a direct communication mode, so that the unmanned mine car always keeps good communication quality and always works normally.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of communication, and particularly relates to a remote communication method and system for unmanned mine cars. BACKGROUND

[0002] The mine area has complex terrain, and there are obstacles such as open-pit mines, mountains, and stockyards. When radio waves (such as 4G / 5G, Wi-Fi, or special wireless frequency bands) propagate, they will be blocked by the terrain, resulting in diffraction loss and multipath effect, which leads to a decrease in signal strength, an increase in delay, or even interruption. For example, when the mine car enters the bottom of the open-pit mine, the surrounding rock wall may completely block the base station signal; the metal ore in the stockyard can reflect electromagnetic waves, interfering with communication stability.

[0003] Therefore, the unmanned mine car may be blocked by the terrain in the mine area, resulting in low communication quality, which affects the normal work of the unmanned mine car, and needs to be improved. SUMMARY

[0004] Therefore, it is necessary to provide a remote communication method and system for unmanned mine cars in view of the above problems.

[0005] The embodiment of the present application is implemented as follows: a remote communication method for an unmanned mine car, comprising the following steps:

[0006] A three-dimensional terrain model of the mine area is constructed, and the electromagnetic wave propagation path loss is calculated in real time (based on the ITU-R P.526 diffraction model). If it is predicted that the target unmanned mine car may be blocked by the terrain after a dynamic time threshold T (T = ΔT + safety margin, ΔT is the estimated time of entering the blind area) and the communication quality is lower than the threshold (such as RSRP ≤ -110 dBm or packet loss rate ≥ 15%), the direct communication mode is changed to the intermediate communication mode;

[0007] Relay nodes that meet the spatial position, communication quality, and motion state are selected from other unmanned mine cars; the base station controls remote communication with the target unmanned mine car through the relay nodes;

[0008] When it is confirmed that the terrain blocking risk is removed (the diffraction path loss decreases by ≥3 dB), and the communication quality in the direct communication mode is higher than the threshold for a duration of Δt (Δt ≥ 3 times the communication period), the base station controls remote communication with the target unmanned mine car directly, and the intermediate communication mode is changed to the direct communication mode.

[0009] In one embodiment, the present application provides a remote communication method for unmanned mine cars, which builds a three-dimensional terrain model of the mine area, calculates the electromagnetic wave propagation path loss in real time (based on the ITU-R P.526 diffraction model), and if it is predicted that the target unmanned mine car may be blocked by the terrain after a dynamic time threshold T (T = ΔT + safety margin, ΔT is the estimated time of entering the blind area) to cause the communication quality to be below the threshold (such as RSRP≤-110dBm or packet loss rate≥15%), then the direct communication mode is changed to the intermediate communication mode, which specifically includes:

[0010] Fusing satellite images of the mine area, laser radar and real-time position data of the mine car, a dynamically updated three-dimensional terrain model of the mine area is built, and the obstacle distribution and base station coordinates are marked;

[0011] Based on the international standard propagation model, the signal attenuation path caused by the terrain obstruction is analyzed, and the risk area that may be caused by obstacles to cause the communication quality (RSRP, packet loss rate) to be below the threshold within the next 30 seconds is predicted, and the obstacles include mountains and ore piles;

[0012] According to the time ΔT of entering the blind area predicted by the motion trajectory of the mine car, the safety margin is calibrated by superimposing the historical communication interruption data to generate a dynamic time threshold T, and when the mine car is expected to reach the risk area within the dynamic time threshold T, the direct communication mode is changed to the intermediate communication mode.

[0013] In one embodiment, the present application provides a remote communication method for unmanned mine cars, which selects relay nodes meeting the spatial position, communication quality and motion state from other unmanned mine cars; and the specific steps of controlling the base station to perform remote communication with the target unmanned mine car through the relay nodes include:

[0014] According to the real-time positioning data of the unmanned mine car and the three-dimensional digital map of the mine area, the relative distance between the target unmanned mine car and other unmanned mine cars is calculated, and candidate mine cars with a distance of≤300m are selected (based on the theoretical coverage radius of 5G-NR FR1 frequency band);

[0015] Using a trajectory prediction algorithm, the driving path of the target unmanned mine car within the next 30 seconds is predicted in combination with the motion state (speed, direction) of the target unmanned mine car and the mine area terrain data, and candidate mine cars that may enter the signal blind area (such as blind area caused by curve obstruction and base station coverage edge) are excluded to form a primary screening list;

[0016] The communication parameters of the mine cars in the primary screening list are collected in real time by the vehicle-mounted 5G module: RSRP≥-95dBm (to ensure basic signal strength), SINR≥10dB (to suppress channel noise interference), and channel utilization rate≤60% (to avoid network congestion risk), and the mine cars meeting all the conditions are included in the secondary screening list;

[0017] In combination with the IMU data, the instantaneous acceleration of the mine car in the secondary screening list is monitored. If the acceleration or deceleration is greater than a set absolute value (e.g., > 2 m / s2), it is determined to be an unstable node and is removed, and a tertiary screening list is generated;

[0018] The angle between the speed vector of the mine car in the tertiary screening list and the target unmanned mine car is calculated. Only the mine car with an angle ≤ 45° (to ensure the same direction of movement) is retained. The mine car with the smallest angle is selected as the relay node (to maximize the link duration). The base station controls the relay node and the target unmanned mine car to perform remote communication.

[0019] In one embodiment, the present application provides a remote communication method for an unmanned mine car. When the terrain shielding risk is confirmed to be removed (the diffraction path loss decreases by ≥ 3 dB), and the communication quality in the direct communication mode for a duration of Δt is higher than a threshold value, Δt ≥ 3 times the communication period, the base station directly performs remote communication with the target unmanned mine car. In the step of changing from the intermediate communication mode to the direct communication mode, it specifically includes:

[0020] The electromagnetic wave diffraction loss change between the target unmanned mine car and the base station is continuously monitored. When it is detected that the path loss continuously decreases by 3 dB, it is confirmed that the terrain shielding risk is removed.

[0021] The key indicators of communication quality (such as RSRP, packet loss rate, etc.) are collected in real time. It is confirmed that the communication quality is continuously higher than the set threshold value for a duration of Δt, Δt ≥ 3 times the communication period.

[0022] The base station directly performs remote communication with the target unmanned mine car, and changes from the intermediate communication mode to the direct communication mode.

[0023] In one embodiment, the present application provides a remote communication method for an unmanned mine car. After the step of calculating the angle between the speed vector of the mine car in the tertiary screening list and the target unmanned mine car, only the mine car with an angle ≤ 45° (to ensure the same direction of movement) is retained. The mine car with the smallest angle is selected as the relay node (to maximize the link duration). The base station controls the relay node and the target unmanned mine car to perform remote communication, the step further includes:

[0024] Send instructions to the relay node to maintain the current mode, and prohibit the relay node from responding to control commands other than the emergency mode (such as energy-saving mode switching, task priority change).

[0025] Continuously monitor the speed vector and communication stability of the relay node. If the angle exceeds 45° or the signal is interrupted, immediately re-trigger the selection of a new relay node.

[0026] In one embodiment, the present application provides a remote communication system for unmanned mine car, comprising:

[0027] A communication quality judgment module is configured to construct a three-dimensional terrain model of a mine area, calculate a path loss of electromagnetic wave propagation in real time (based on an ITU-R P.526 diffraction model), and change a direct communication mode to an intermediate communication mode if a target unmanned mine car is predicted to be blocked by terrain and the communication quality is lower than a threshold (e.g., RSRP≤-110 dBm or a packet loss rate≥15%) after a dynamic time threshold T (T=ΔT+ safety margin, ΔT is an estimated time for entering a blind area).

[0028] A relay node selection module is configured to select a relay node from other unmanned mine cars according to spatial position, communication quality and motion state, and control a base station to perform remote communication with the target unmanned mine car through the relay node.

[0029] A communication mode recovery module is configured to change the intermediate communication mode to the direct communication mode when it is confirmed that the terrain blocking risk is removed (the path loss of diffraction is reduced by≥3 dB) and the communication quality is higher than the threshold in the direct communication mode for a time Δt (Δt≥3 times a communication period).

[0030] In one embodiment, the present application provides a remote communication system for unmanned mine car, and the communication quality judgment module comprises:

[0031] A mine area three-dimensional construction unit is configured to fuse satellite images of a mine area, laser radar and real-time position data of a mine car, construct a three-dimensional terrain model of the mine area which can be dynamically updated, and mark obstacle distribution and base station coordinates.

[0032] A risk area prediction unit is configured to analyze a signal attenuation path caused by terrain blocking based on an international standard propagation model, and predict a risk area in which the communication quality (RSRP, packet loss rate) is lower than a threshold within 30 seconds in the future due to obstacles, the obstacles including mountains and ore piles.

[0033] A risk prediction processing unit is configured to predict a time ΔT for the mine car to enter a blind area according to a motion trajectory of the mine car, superimpose a safety margin calibrated based on historical communication interruption data, and generate a dynamic time threshold T, and change the direct communication mode to the intermediate communication mode when the mine car is predicted to reach the risk area within the dynamic time threshold T.

[0034] In one embodiment, the present application provides a remote communication system for unmanned mine car, and the relay node selection module comprises:

[0035] A relative distance screening unit is configured to calculate the relative distance between the target unmanned mine car and other unmanned mine cars according to the real-time positioning data of the unmanned mine car and the three-dimensional digital map of the mine area, and to screen out candidate mine cars with a distance of ≤300 meters (based on the theoretical coverage radius of the 5G-NR FR1 frequency band);

[0036] A driving path screening unit is configured to use a trajectory prediction algorithm to predict the driving path of the target unmanned mine car within 30 seconds in the future in combination with the motion state (speed, direction) of the target unmanned mine car and the mine area terrain data, to eliminate candidate mine cars that may enter a signal blind area (such as a blind area caused by a curve), and to form a first screening list;

[0037] A communication quality screening unit is configured to collect, through the vehicle-mounted 5G module, the communication parameters of the mine cars in the first screening list in real time: RSRP≥-95dBm (to ensure basic signal strength), SINR≥10dB (to suppress channel noise interference), and channel utilization rate≤60% (to avoid network congestion risk), and to include mine cars meeting all conditions in a second screening list;

[0038] An unstable node screening unit is configured to monitor the instantaneous acceleration of the mine cars in the second screening list in combination with the IMU data, to determine that a mine car is an unstable node and to eliminate the unstable node if the mine car exhibits a sudden acceleration or sudden deceleration greater than a set absolute value (such as >2m / s²), and to generate a third screening list;

[0039] A relay node determination unit is configured to calculate the speed vector angle between the mine cars in the third screening list and the target unmanned mine car, to retain only mine cars with an angle ≤45° (to ensure that the motion directions are similar), and to select a mine car with the smallest angle as a relay node (to maximize the link duration), and to control the base station to perform remote communication with the target unmanned mine car through the relay node.

[0040] In one embodiment, the present application provides a remote communication system for an unmanned mine car, and the communication mode recovery module comprises:

[0041] A risk removal confirmation unit is configured to continuously monitor the change in electromagnetic wave diffraction loss between the target unmanned mine car and the base station, and to confirm that the terrain shielding risk is removed when a continuous decrease in path loss of 3dB is detected;

[0042] A communication quality confirmation unit is configured to collect key indicators of communication quality (such as RSRP, packet loss rate, etc.) in real time, to confirm that the communication quality is continuously higher than a set threshold within a time Δt, and to confirm that Δt≥3 times the communication period;

[0043] A communication mode change unit is configured to control the base station to perform remote communication directly with the target unmanned mine car, and to change the intermediate communication mode to a direct communication mode.

[0044] In one of the embodiments, the application provides a remote communication system of unmanned mine car, the relay node selection module further comprises:

[0045] The mode maintaining unit is used for sending an instruction to the relay node to keep the current mode, and prohibiting the relay node from responding to other control commands (such as energy-saving mode switching and task priority changing) except for the emergency mode.

[0046] The relay node replacing unit is used for continuously monitoring the speed vector and communication stability of the relay node, and immediately triggering the screening of a new relay node if the included angle exceeds 45° or the signal is interrupted.

[0047] Compared with the prior art, the application has the beneficial effects that: the application changes the communication mode in advance by judging whether the unmanned mine car is likely to cause the communication quality to be lower than the threshold value due to the terrain obstruction, changes from the direct communication mode to the intermediate communication mode, and changes from the intermediate communication mode to the direct communication mode after confirming that the terrain obstruction risk is removed and judging the communication quality, so that the unmanned mine car always maintains good communication quality and always works normally. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 A flowchart of a remote communication method of an unmanned mine car provided for the embodiment of the application is shown.

[0049] Figure 2 A flowchart of judging the communication quality provided for the embodiment of the application is shown.

[0050] Figure 3 A flowchart of screening the relay node provided for the embodiment of the application is shown.

[0051] Figure 4 A flowchart of restoring the communication mode provided for the embodiment of the application is shown.

[0052] Figure 5 A flowchart of maintaining the working state and replacing the relay node provided for the embodiment of the application is shown.

[0053] Figure 6 A schematic diagram of a remote communication system of an unmanned mine car provided for the embodiment of the application is shown.

[0054] Figure 7 A schematic diagram of a communication quality judging module provided for the embodiment of the application is shown.

[0055] Figure 8 A first part of a schematic diagram of a relay node selection module provided for the embodiment of the application is shown.

[0056] Figure 9 A schematic diagram of a communication mode restoring module provided for the embodiment of the application is shown.

[0057] Figure 10 The second part of the schematic diagram of the relay node selection module provided by the embodiment of the application. DETAILED DESCRIPTION

[0058] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0059] In one embodiment, as shown in Figure 1 A remote communication method of an unmanned mine car, comprising the following steps:

[0060] Step S1, a three-dimensional terrain model of a mine area is constructed, and an electromagnetic wave propagation path loss is calculated in real time (based on the ITU-RP.526 diffraction model). If it is predicted that the target unmanned mine car may be blocked by terrain to cause the communication quality to be lower than a threshold value (such as RSRP≤-110dBm or the packet loss rate≥15%) after a dynamic time threshold T (T=ΔT+ safety margin, ΔT is the estimated time of entering the blind area), the direct communication mode is changed to the intermediate communication mode.

[0061] Step S2, relay nodes meeting the spatial position, communication quality and motion state are screened from other unmanned mine cars; and the base station is controlled to perform remote communication through the relay nodes and the target unmanned mine car.

[0062] Step S3, when it is confirmed that the terrain blocking risk is removed (the diffraction path loss decreases by≥3dB), and the communication quality under the direct communication mode is higher than the threshold value for a continuous time Δt (Δt≥3 times the communication period), the base station is controlled to perform remote communication directly with the target unmanned mine car, and the intermediate communication mode is changed to the direct communication mode.

[0063] The high-precision three-dimensional terrain data is used to construct a three-dimensional terrain model of a mining area, and the path loss of electromagnetic waves in complex terrain is calculated in real time by combining the ITU-R P.526 diffraction model; when it is predicted that the target unmanned mine car will be blocked by mountains / mines after a dynamic time threshold T (T = AT + safety margin) and the communication quality will deteriorate (such as RSRP ≤-110 dBm or packet loss rate exceeds 15%), the communication mode switching mechanism is triggered, and the direct communication mode is changed to the intermediate communication mode; the direct communication mode is that the base station directly connects the target unmanned mine car, and the intermediate communication mode is that the base station communicates with the target unmanned mine car through a relay node; the relay node that meets the communication quality (such as RSSI ≥-95 dBm), the stable motion state, and is located in the signal relay area of the base station and the target unmanned mine car is selected from the adjacent mine cars by a spatial position screening algorithm, and a multi-hop link of the base station, the relay node, and the target unmanned mine car is established; when it is detected that the diffraction loss caused by the shielding terrain decreases by ≥3 dB (such as the mine car bypasses the obstacle to restore the line of sight), and the direct connection signal quality is stable and meets the standard in the next three communication periods, the base station direct connection mode is automatically switched back, forming a full closed-loop communication guarantee system of terrain risk prediction, relay network reconstruction, and channel quality recovery, so that the unmanned mine car always maintains good communication quality and always works normally.

[0064] In one embodiment, as shown in Figure 2 The present application provides a remote communication method of an unmanned mine car, and the step S1 is to construct a three-dimensional terrain model of a mining area and calculate the path loss of electromagnetic wave propagation in real time (based on the ITU-R P.526 diffraction model); if it is predicted that the target unmanned mine car will be blocked by terrain after a dynamic time threshold T (T = AT + safety margin, AT is the estimated time of entering the blind area) and the communication quality will be lower than the threshold (such as RSRP ≤-110 dBm or packet loss rate ≥15%), the direct communication mode is changed to the intermediate communication mode in the step of changing the direct communication mode to the intermediate communication mode.

[0065] Step S11, fuse the satellite image of the mining area, the laser radar, and the real-time position data of the mine car, construct a dynamically updated three-dimensional terrain model of the mining area, and mark the obstacle distribution and the base station coordinates;

[0066] Step S12, based on the international standard propagation model, analyze the signal attenuation path caused by terrain shielding, and predict the risk area in which the communication quality (RSRP, packet loss rate) will be lower than the threshold in the next 30 seconds due to obstacles, and the obstacles include mountains and mine piles;

[0067] Step S13, predict the time AT of entering the blind area according to the motion trajectory of the mine car, superimpose the safety margin calibrated by the historical communication interruption data, and generate a dynamic time threshold T; when the mine car is predicted to reach the risk area within the dynamic time threshold T, the direct communication mode is changed to the intermediate communication mode.

[0068] The specific implementation process of step S11 is as follows: step S111, multi-source data acquisition and registration: macroscopic terrain images of a mining area are acquired through satellite remote sensing (resolution ≤ 0.5 m), centimeter-level precision point cloud data are generated by using a vehicle-mounted laser radar (LiDAR) scanning, and real-time coordinates are integrated by using a mine vehicle GNSS / INS positioning system (positioning accuracy ≤ 10 cm). Multi-source data spatial alignment is achieved through coordinate system conversion (WGS84 / UTM).

[0069] Step S112, three-dimensional modeling and dynamic updating: based on a modeling tool such as Bentley ContextCapture, satellite image texture and LiDAR point cloud are fused to construct an initial three-dimensional terrain grid model; ground surface changes (such as mine heap displacement and road collapse) are detected in real time through mine vehicle motion trajectory data, and an incremental updating algorithm (such as octree spatial segmentation) is used to locally correct the geometric structure of the model.

[0070] Step S113, intelligent obstacle identification: a PointNet++ point cloud deep learning framework is applied to perform semantic segmentation on static obstacles (mountains and buildings) and dynamic obstacles (moving devices) in LiDAR data, and the obstacle boundary is verified in combination with mine vehicle obstacle avoidance radar data to generate an obstacle vector layer with attribute labels (height and material).

[0071] Step S114, communication element labeling: base station coordinates (longitude, latitude and altitude) and antenna radiation parameters are embedded in the three-dimensional model, and the spatial relationship between the coverage range (line-of-sight / non-line-of-sight area) of the base station and the obstacles is quickly queried through a spatial database (PostGIS), thereby providing a geographic information basis for subsequent electromagnetic propagation calculation.

[0072] In one embodiment, as shown in Figure 3 The present application provides a remote communication method of an unmanned mine vehicle, and the step S2 of screening a relay node meeting spatial position, communication quality and motion state from other unmanned mine vehicles; in the step of controlling the base station to perform remote communication through the relay node and the target unmanned mine vehicle, the step specifically comprises:

[0073] Step S21, according to the real-time positioning data of the unmanned mine vehicle and the three-dimensional digital map of the mining area, the relative distance between the target unmanned mine vehicle and other unmanned mine vehicles is calculated, and candidate mine vehicles with a distance ≤ 300 meters are screened out (based on the theoretical coverage radius of the 5G-NR FR1 frequency band);

[0074] Step S22, using trajectory prediction algorithm, combining the motion state (speed, direction) of the target unmanned mine car and the mine area terrain data, predicting its driving path within 30 seconds in the future, eliminating candidate mine cars that may enter the signal blind area (such as blind area caused by curve shielding, base station coverage edge), and forming a first screening list;

[0075] Step S23, real-time collection of communication parameters of mine cars in the first screening list through the vehicle-mounted 5G module: RSRP≥-95dBm (guarantee basic signal strength), SINR≥10dB (suppress channel noise interference), channel utilization rate≤60% (avoid network congestion risk), mine cars meeting all conditions are included in the second screening list;

[0076] Step S24, combining IMU data to monitor the instantaneous acceleration of mine cars in the second screening list, if the sudden acceleration or deceleration is greater than the set absolute value (such as >2m / s²), it is determined as unstable node and eliminated, and the third screening list is generated;

[0077] Step S25, calculating the speed vector angle between the mine cars in the third screening list and the target unmanned mine car, only keeping the mine cars with an angle ≤45° (to ensure the same motion direction), and selecting the mine car with the smallest angle as the relay node (to maximize the link duration), and controlling the base station to communicate with the target unmanned mine car through the relay node.

[0078] In step S21, for the target unmanned mine car, the three-dimensional Euclidean distance formula is used to calculate the straight-line distance between it and the surrounding mine cars, and the elevation is corrected combined with the mine area digital terrain model (DTM) to exclude the pseudo-neighbors caused by the terrain undulation; Through spatial range query, the candidate mine car set with a relative distance ≤300 meters is selected, the theoretical coverage radius of FR1 frequency band (450MHz-6GHz) is usually in the order of 300 meters to several kilometers, which is affected by the base station transmission power, antenna configuration and environmental factors, therefore, 300 meters is set to ensure the communication quality.

[0079] In one embodiment, as shown in Figure 4 The present application provides a remote communication method for unmanned mine cars, and the step S3 includes the following steps:

[0080] Step S31, continuously monitoring the electromagnetic wave diffraction loss change between the target unmanned mine car and the base station, and when the detection shows that the path loss continuously decreases by 3dB, it is confirmed that the terrain shielding risk is removed;

[0081] Step S32, real-time collection of key indicators of communication quality (such as RSRP, packet loss rate, etc.), confirming that the communication quality is continuously higher than the set threshold within Δt time, Δt≥3 times the communication period;

[0082] Step S33, controlling the base station to directly and remotely communicate with the target unmanned mine car, changing from the intermediate communication mode to the direct communication mode.

[0083] In step S31, when there is a terrain obstruction (such as a mountain or a building) between the mine car and the base station, the signal needs to be transmitted by diffraction, at which time the path loss will increase significantly (typical diffraction loss can reach 10-20 dB). When a continuous decrease of 3 dB in path loss is detected (corresponding to an increase of about 50% in signal power), it indicates that the mine car has moved to the edge of the obstacle or has left the obstructed area, and the diffraction component in the electromagnetic wave propagation path has decreased, and the direct path gradually regains its dominant position, so it can be determined that the terrain obstruction risk has been removed.

[0084] In one embodiment, as shown in Figure 5 The present application provides a remote communication method for an unmanned mine car, wherein step S25, the angle between the speed vector of the mine car and the target unmanned mine car in the three-time screening list is calculated, only the mine car with an angle ≤45° (to ensure that the motion direction converges) is retained, and the mine car with the smallest angle is selected as the relay node (to maximize the link duration), and after the step of controlling the base station to remotely communicate with the target unmanned mine car through the relay node, the method further comprises:

[0085] Step S26, sending an instruction to the relay node to keep the current mode, and prohibiting the relay node from responding to control commands other than the emergency mode (such as energy-saving mode switching and task priority change);

[0086] Step S27, continuously monitoring the speed vector and communication stability of the relay node, and if the angle exceeds 45° or the signal is interrupted, triggering the screening of a new relay node immediately.

[0087] In step S26, the core purpose of requiring the relay node to keep the current mode is to lock the running state of the relay node to ensure the stability and reliability of the communication link, thereby indirectly ensuring the communication quality of the target unmanned mine car. The specific reasons are as follows:

[0088] Avoiding link fluctuations caused by mode switching: If the relay node is allowed to respond to commands such as energy-saving mode switching or task priority change, it may reduce the transmission power (energy-saving mode) or temporarily interrupt the communication (task reconfiguration), directly affecting the signal-to-noise ratio (SNR) and data transmission continuity of the relay link;

[0089] Maintain relay node resource specialization: Force relay nodes to maintain the current mode (such as fixed power, frequency band and protocol stack), which can avoid time slot conflicts or channel switching delays introduced by dynamic resource allocation algorithms (such as DRX mechanism in LTE / 5G), and ensure strict synchronization of communication period (TTI);

[0090] Reduce control plane interference: Inhibit non-emergency command response to reduce the control plane signaling processing load of relay nodes (such as RRC reconfiguration, measurement report reporting), thereby reducing the risk of real-time degradation caused by CPU resource competition;

[0091] Emergency mode priority guarantee: Only allow response to emergency mode (such as collision avoidance instruction), to ensure that the relay node can still quickly switch to a high-reliability state in extreme scenarios, and avoid safety accidents caused by communication interruption.

[0092] In one embodiment, as shown in Figure 6 The present application provides a remote communication system for unmanned mine cars, comprising:

[0093] A communication quality judgment module 1 is used to build a three-dimensional terrain model of the mine area, calculate the electromagnetic wave propagation path loss in real time (based on ITU-R P.526 diffraction model), and if it is predicted that the target unmanned mine car may be blocked by the terrain after a dynamic time threshold T (T = ΔT + safety margin, ΔT is the estimated time to enter the blind area) Communication quality is lower than the threshold (such as RSRP≤-110dBm or packet loss rate≥15%), change from direct communication mode to intermediate communication mode;

[0094] A relay node selection module 2 is used to select relay nodes that meet the spatial position, communication quality and motion state from other unmanned mine cars; control the base station to communicate with the target unmanned mine car through the relay node;

[0095] A communication mode recovery module 3 is used to confirm that the terrain blocking risk is removed (the diffraction path loss drops by ≥3dB), and the communication quality in the direct communication mode is higher than the threshold for Δt time, Δt≥3 times the communication period, and control the base station to communicate with the target unmanned mine car directly, change from intermediate communication mode to direct communication mode.

[0096] The ITU-R P.526 diffraction model is a standard method recommended by the International Telecommunication Union (ITU) for calculating the path loss of electromagnetic waves when diffraction occurs at the edge of an obstacle. This model simulates the diffraction attenuation effect of electromagnetic waves encountering obstacles such as mountains and buildings through geometric optics theory, and is particularly suitable for signal propagation prediction in non-line-of-sight (NLOS) scenarios. The core principle is to simplify the obstacle into a knife-edge shape, based on parameters such as obstacle height, transmitter-receiver distance, and wavelength, to calculate the diffraction loss value, thereby evaluating the reliability of communication links in complex terrain.

[0097] In one embodiment, as shown in Figure 7 The present application provides a remote communication system for unmanned mine cars, which includes a communication quality judgment module 1 comprising:

[0098] A mine area three-dimensional construction unit 11 is used to fuse mine area satellite images, laser radar, and real-time position data of mine cars, construct a dynamically updateable mine area three-dimensional terrain model, and mark obstacle distribution and base station coordinates;

[0099] A risk area prediction unit 12 is used to analyze signal attenuation paths caused by terrain shielding based on international standard propagation models, predict risk areas that may cause communication quality (RSRP, packet loss rate) to be below a threshold value within the next 30 seconds due to obstacles, and the obstacles include mountains and mine piles;

[0100] A risk prediction processing unit 13 is used to predict the time ΔT of entering a blind area according to the motion trajectory of the mine car, superimpose historical communication interruption data to calibrate a safety margin, generate a dynamic time threshold T, and change the direct communication mode to the intermediate communication mode when the mine car is expected to reach the risk area within the dynamic time threshold T.

[0101] In the risk area prediction unit 12, based on the mine area three-dimensional terrain model and the real-time trajectory of the mine car, the motion path of the mine car in the next 30 seconds is predicted by Kalman filtering; secondly, virtual communication links between the base station and the mine car are generated along the predicted path at time steps (such as 5 sampling points per second), and a ray casting algorithm (Ray Casting) is used to detect whether the path is blocked by dynamically updated mine piles or mountains. For the shielding scenario, the ITU-R P.526 diffraction model is called to calculate the diffraction loss, combined with the free space loss, multipath effect (3GPP TR 38.901 model), and mine car receiving sensitivity, to output the RSRP prediction value and the bit error rate (mapped to the packet loss rate) of each sampling point in real time; finally, a communication quality heat map is generated by spatial interpolation, and high-risk areas with RSRP < -110 dBm or packet loss rate > 15% are marked.

[0102] In one embodiment, as shown in Figure 8 The present application provides a remote communication system for unmanned mine cars, which includes a relay node selection module 2 comprising:

[0103] A relative distance screening unit 21 is configured to calculate the relative distance between the target unmanned mine truck and other unmanned mine trucks according to the real-time positioning data of the unmanned mine truck and the three-dimensional digital map of the mine area, and screen out candidate mine trucks with a distance of ≤300 meters (based on the theoretical coverage radius of the 5G-NR FR1 frequency band);

[0104] A driving path screening unit 22 is configured to use a trajectory prediction algorithm to predict the driving path of the target unmanned mine truck within 30 seconds in the future in combination with the motion state (speed, direction) of the target unmanned mine truck and the mine area terrain data, eliminate candidate mine trucks that may enter a signal blind area (such as a blind area caused by a curve), and form a primary screening list.

[0105] A communication quality screening unit 23 is configured to collect the communication parameters of the mine trucks in the primary screening list in real time through the vehicle-mounted 5G module: RSRP≥-95dBm (to ensure the basic signal strength), SINR≥10dB (to suppress channel noise interference), and channel utilization rate≤60% (to avoid network congestion risk), so that the mine trucks meeting all the conditions are included in a secondary screening list.

[0106] An unstable node screening unit 24 is configured to monitor the instantaneous acceleration of the mine trucks in the secondary screening list in combination with the IMU data, and if the sudden acceleration or sudden deceleration is greater than a set absolute value (such as >2m / s²), the unstable node is determined and eliminated, and a tertiary screening list is generated.

[0107] A relay node determination unit 25 is configured to calculate the speed vector angle between the mine trucks in the tertiary screening list and the target unmanned mine truck, and only keep the mine trucks with an angle ≤45° (to ensure that the motion directions are similar), and select the mine truck with the smallest angle as the relay node (to maximize the link duration), so that the base station controls the remote communication with the target unmanned mine truck through the relay node.

[0108] In the relay node determination unit 25, the speed vector data (including the speed size, heading angle, and pitch angle) of each mine truck in the tertiary screening list is obtained in real time, which is converted into a three-dimensional speed vector. For the target unmanned mine truck, the speed vector angle between the target unmanned mine truck and the candidate mine truck is calculated using the vector dot product formula, and the heading angle measurement noise is eliminated by using Kalman filtering. After screening the mine trucks with an angle ≤45°, the mine trucks are sorted in ascending order of the angle, and the mine truck with the smallest angle is selected as the relay node.

[0109] In one embodiment, as shown in FIG. 1, Figure 9 the present application provides a remote communication system for unmanned mine trucks, and the communication mode recovery module 3 comprises:

[0110] The risk release confirmation unit 31 is configured to continuously monitor the change of electromagnetic wave diffraction loss between the target unmanned mine car and the base station, and confirm that the terrain shielding risk is released when detecting that the path loss continuously decreases by 3 dB.

[0111] The communication quality confirmation unit 32 is configured to collect key indicators (such as RSRP, packet loss rate, etc.) of communication quality in real time, and confirm that the communication quality continuously exceeds the set threshold within Δt time, Δt≥3 times of the communication period.

[0112] The communication mode changing unit 33 is configured to control the base station to directly and remotely communicate with the target unmanned mine car, and change the intermediate communication mode to the direct communication mode.

[0113] In the communication quality confirmation unit 32, the core reason for setting Δt≥3 times of the communication period is to exclude transient interference and verify the stability of the communication quality. More than 3 times of independent sampling can form a basic statistical sample, and short-time fluctuations (such as burst packet loss and instantaneous RSRP jitter) can be eliminated through sliding average or median filtering.

[0114] In one embodiment, as shown in FIG. 2, the present application provides a remote communication system for an unmanned mine car, and the relay node selection module 2 further comprises: Figure 10

[0115] The mode maintaining unit 26 is configured to send an instruction to the relay node to maintain the current mode, and prohibit the relay node from responding to other control commands (such as energy-saving mode switching and task priority changing) except for the emergency mode.

[0116] The relay node changing unit 27 is configured to continuously monitor the speed vector and communication stability of the relay node, and immediately re-trigger the screening of a new relay node if the included angle exceeds 45° or the signal is interrupted.

[0117] In the mode maintaining unit 26, the running state of the relay node can be further controlled. Under the condition of not affecting safety, the current speed and position of the relay node are maintained to ensure that the motion direction and the target unmanned mine car tend to be the same (reduce the relative displacement speed), and the relative motion of the two is the slowest (the directions are similar or almost the same), thereby significantly prolonging the effective communication distance maintenance time between the two (maximizing the link duration), reducing the risk of relay link breakage through the consistency of physical motion, and ensuring the stability of remote communication.

[0118] ​It should be understood that, although the steps in the flowcharts of the embodiments of the present application are shown in sequence according to the arrows, the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of the steps is not strictly limited in sequence, and the steps can be executed in other sequences. Moreover, at least some of the steps in the embodiments can include multiple sub-steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of the sub-steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least some of the other steps or sub-steps or stages of the other steps.

[0119] The technical features of the above-described embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above-described embodiments are described, but it should be understood that any combination of the technical features is within the scope of the present disclosure as long as the combination does not result in contradictions.

[0120] The above-described embodiments only express several implementation manners of the present application, which are described in detail and specifically, but should not be understood as limitations on the patent scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which are within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

[0121] The above-described embodiments only express several implementation manners of the present application, which are described in detail and specifically, but should not be understood as limitations on the patent scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which are within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

[0122] In addition, it should be understood that, although the present application is described in the form of embodiments, each embodiment does not necessarily contain only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in the embodiments can be combined appropriately to form other embodiments that can be understood by those skilled in the art.

Claims

1. A remote communication method for an unmanned mining truck, characterized in that, The remote communication method for this driverless mining truck includes the following steps: Construct a three-dimensional terrain model of the mining area and calculate the electromagnetic wave propagation path loss in real time. If it is predicted that the target unmanned mining vehicle may have communication quality lower than the threshold due to terrain occlusion after a dynamic time threshold T, then switch from direct communication mode to intermediate communication mode. Select relay nodes from other unmanned mining vehicles that meet the requirements of spatial location, communication quality, and motion status; control the base station to conduct remote communication with the target unmanned mining vehicle through the relay nodes; Once the risk of terrain obstruction is confirmed to be eliminated, and the communication quality in direct communication mode for a duration of Δt is higher than the threshold (Δt ≥ 3 times the communication cycle), the control base station directly communicates with the target unmanned mining vehicle remotely, changing from intermediate communication mode to direct communication mode.

2. The remote communication method for unmanned mining trucks according to claim 1, characterized in that, The step of constructing a three-dimensional terrain model of the mining area, calculating electromagnetic wave propagation path loss in real time, and changing from direct communication mode to intermediate communication mode if the predicted communication quality of the target unmanned mining vehicle may fall below the threshold due to terrain obstruction after a dynamic time threshold T includes: By integrating satellite imagery of the mining area, lidar data, and real-time location data of mining trucks, a dynamically updatable 3D terrain model of the mining area is constructed, marking the distribution of obstacles and the coordinates of base stations. Based on the international standard propagation model, the signal attenuation path caused by terrain obstruction is analyzed, and the risk areas in the next 30 seconds that may have communication quality below the threshold due to obstacles are predicted. Obstacles include mountains and mine piles. Based on the predicted entry time ΔT of the mine car's movement trajectory into the blind zone, and by superimposing historical communication interruption data to calibrate the safety margin, a dynamic time threshold T is generated. When the mine car is expected to reach the risk area within the dynamic time threshold T, the communication mode is changed from direct communication mode to intermediate communication mode.

3. The remote communication method for unmanned mining trucks according to claim 1, characterized in that, The steps of selecting relay nodes from other unmanned mining vehicles that meet the requirements of spatial location, communication quality, and motion status, and controlling the base station to conduct remote communication between the relay nodes and the target unmanned mining vehicle, specifically include: Based on the real-time positioning data of the unmanned mining truck and the three-dimensional digital map of the mining area, the relative distance between the target unmanned mining truck and other unmanned mining trucks is calculated, and candidate mining trucks with a distance of ≤300 meters are selected. Using a trajectory prediction algorithm, combined with the motion status of the target unmanned mining truck and the terrain data of the mining area, the driving path of the target unmanned mining truck in the next 30 seconds is predicted, and candidate mining trucks that may enter the signal blind zone are eliminated to form a screening list. The communication parameters of mining trucks in the first screening list are collected in real time by the vehicle-mounted 5G module: RSRP≥-95dBm, SINR≥10dB, channel utilization ≤60%. Mining trucks that meet all the conditions are included in the second screening list. By combining IMU data to monitor the instantaneous acceleration of the mining trucks in the secondary screening list, if a sudden acceleration or deceleration exceeds a set absolute value, it is determined to be an unstable node and removed, generating a tertiary screening list; Calculate the velocity vector angle between the mining truck and the target unmanned mining truck in the three filtering lists, retain only the mining truck with an angle ≤ 45°, select the mining truck with the smallest angle as the relay node, and control the base station to communicate remotely with the target unmanned mining truck through the relay node.

4. The remote communication method for unmanned mining trucks according to claim 1, characterized in that, The step of controlling the base station to directly communicate with the target unmanned mining vehicle remotely after confirming that the terrain obstruction risk has been eliminated and that the communication quality in the direct communication mode for a continuous time Δt is higher than the threshold, with Δt ≥ 3 times the communication cycle, and changing from the intermediate communication mode to the direct communication mode, specifically includes: Continuously monitor the changes in electromagnetic wave diffraction loss between the target unmanned mining truck and the base station. When the path loss is detected to decrease continuously by 3dB, the risk of terrain occlusion is confirmed to be eliminated. Real-time acquisition of key communication quality indicators confirms that the communication quality remains above a set threshold for a time interval Δt, where Δt ≥ 3 times the communication cycle. The control base station communicates remotely with the target unmanned mining vehicle, changing from an intermediate communication mode to a direct communication mode.

5. The remote communication method for unmanned mining trucks according to claim 3, characterized in that, The calculation of the velocity vector angle between the mining truck and the target unmanned mining truck in the three-stage screening list, retaining only mining trucks with an angle ≤ 45°, and selecting the mining truck with the smallest angle as the relay node, and controlling the base station to conduct remote communication with the target unmanned mining truck through the relay node, further includes: Send instructions to relay nodes to maintain the current mode and prohibit relay nodes from responding to control commands other than those in emergency mode; Continuously monitor the velocity vector and communication stability of relay nodes. If the angle exceeds 45° or the signal is interrupted, immediately re-trigger the selection of new relay nodes.

6. A remote communication system for an unmanned mining truck, characterized in that, The remote communication system of the unmanned mining truck includes: The communication quality judgment module is used to construct a three-dimensional terrain model of the mining area and calculate the electromagnetic wave propagation path loss in real time. If it is predicted that the target unmanned mining vehicle may have communication quality lower than the threshold due to terrain occlusion after a dynamic time threshold T, the module will switch from direct communication mode to intermediate communication mode. The relay node selection module is used to select relay nodes from other unmanned mining vehicles that meet the requirements of spatial location, communication quality, and motion status; the control base station conducts remote communication with the target unmanned mining vehicle through the relay nodes; The communication mode recovery module is used to control the base station to directly communicate with the target unmanned mining vehicle remotely when the terrain obstruction risk is confirmed to be eliminated and the communication quality in the direct communication mode for a continuous time Δt is higher than the threshold, and Δt is ≥ 3 times the communication cycle, and the intermediate communication mode is changed to the direct communication mode.

7. The remote communication system for the unmanned mining truck according to claim 6, characterized in that, The communication quality assessment module includes: The three-dimensional construction unit for the mining area is used to integrate satellite imagery, lidar, and real-time location data of mining trucks to build a dynamically updatable three-dimensional terrain model of the mining area, marking the distribution of obstacles and the coordinates of base stations; The risk area prediction unit is used to analyze the signal attenuation path caused by terrain obstruction based on the international standard propagation model, and predict the risk areas in the next 30 seconds where the communication quality may be lower than the threshold due to obstacles, including mountains and mine piles. The risk prediction and processing unit is used to predict the time ΔT for entering the blind zone based on the movement trajectory of the mining truck, superimpose historical communication interruption data to calibrate the safety margin, and generate a dynamic time threshold T. When the mining truck is expected to reach the risk area within the dynamic time threshold T, it switches from direct communication mode to intermediate communication mode.

8. The remote communication system for unmanned mining trucks according to claim 6, characterized in that, The relay node selection module includes: The relative distance filtering unit is used to calculate the relative distance between the target unmanned mining truck and other unmanned mining trucks based on the real-time positioning data of the unmanned mining truck and the three-dimensional digital map of the mining area, and to filter out candidate mining trucks with a distance ≤ 300 meters. The driving path filtering unit is used to use a trajectory prediction algorithm, combined with the motion status of the target unmanned mining vehicle and the terrain data of the mining area, to predict its driving path in the next 30 seconds, eliminate candidate mining vehicles that may enter the signal blind zone, and form a filtering list. The communication quality screening unit is used to collect the communication parameters of the mining trucks in the primary screening list in real time through the vehicle-mounted 5G module: RSRP≥-95dBm, SINR≥10dB, channel utilization ≤60%, and mining trucks that meet all the conditions are included in the secondary screening list. The unstable node screening unit is used to monitor the instantaneous acceleration of the mine cars in the secondary screening list by combining IMU data. If a sudden acceleration or deceleration exceeds a set absolute value, it is judged as an unstable node and removed, generating a tertiary screening list. The relay node determination unit is used to calculate the velocity vector angle between the mining truck and the target unmanned mining truck in the three-stage screening list, retain only the mining truck with an angle ≤ 45°, select the mining truck with the smallest angle as the relay node, and control the base station to conduct remote communication with the target unmanned mining truck through the relay node.

9. The remote communication system for the unmanned mining truck according to claim 6, characterized in that, The communication mode recovery module includes: The risk removal confirmation unit is used to continuously monitor the change in electromagnetic wave diffraction loss between the target unmanned mining truck and the base station. When the path loss is detected to decrease continuously by 3dB, the terrain occlusion risk is confirmed to be removed. The communication quality confirmation unit is used to collect key indicators of communication quality in real time and confirm that the communication quality is continuously higher than a set threshold within a time Δt, where Δt ≥ 3 times the communication cycle. The communication mode changing unit is used to control the base station to communicate remotely with the target unmanned mining vehicle, changing from intermediate communication mode to direct communication mode.

10. The remote communication system for the unmanned mining truck according to claim 8, characterized in that, The relay node selection module also includes: The mode maintenance unit is used to send instructions to relay nodes to maintain the current mode and prohibit relay nodes from responding to other control commands except for emergency mode. The relay node replacement unit is used to continuously monitor the speed vector and communication stability of the relay node. If the included angle exceeds 45° or the signal is interrupted, it will immediately trigger the screening of a new relay node.

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