Safety disposal method after communication interruption of unattended remote control electric shovel

Abstract

The invention discloses a safety disposal method after communication interruption of an unattended remote control electric shovel. The method comprises the following steps: recording manual control data according to a set frequency; communication heartbeat is monitored in real time, and an emergency stop mechanism is triggered immediately when communication is interrupted; entering a safe disposal state of the bucket; judging whether the electric shovel is in an excavation process or not before shutdown; whether an obstacle exists under the bucket or not is detected; whether obstacles exist in a set range around the bucket of the electric shovel or not is monitored; judging whether the position of the bucket rod is in a preset horizontal interval or not; judging whether the length of the bucket rod extending out of the pushing pinion exceeds a preset length; controlling the lifting mechanism to lower the bucket at a preset lifting speed until the bucket is in contact with the ground; and controlling all the working mechanisms to brake, stopping the rectification system, delaying for preset time, and ending high-voltage stopping. Therefore, according to the method, automatic and safe landing of the heavy-load bucket during communication interruption under the scene of unattended remote control of the electric shovel is achieved, and equipment damage and safety accident risks are effectively avoided.

Description

Technical Field

[0001] This invention relates to a safety handling method for communication interruption of an unattended remote-controlled electric shovel, belonging to the technical field of safety protection for remote-controlled electric shovels in open-pit mines. Background Technology

[0002] With technological advancements and policy incentives, remote control systems are increasingly being deployed on electric shovels in open-pit mines. Currently, most remotely controlled electric shovels still have a human operator in the local cab to assist the remote operator in handling emergencies. However, based on the goal of building unmanned smart mines, the remote control of electric shovels must inevitably evolve towards unmanned operation.

[0003] In existing technologies, a communication detection program is typically installed between the local and remote ends of the electric shovel. When communication is interrupted or excessive latency occurs, the system automatically engages the brakes on the shovel's working mechanism to prevent potential hazards from continued operation under abnormal conditions. Once communication is restored, the remote end can release the brakes, allowing the shovel to resume operation. If communication cannot be restored after an extended period, the local operator will take over, or the bucket will be lowered to the ground and the machine stopped.

[0004] However, when electric shovels are operated unattended locally, serious shortcomings of existing technologies become apparent during remote-controlled production if communication is interrupted and cannot be reconnected quickly. In such cases, the bucket remains suspended in the air for extended periods, posing a significant safety hazard, especially when loaded with material. For example, in large open-pit mines, electric shovel buckets have large capacities, carrying materials weighing several tons or even tens of tons. If the bucket remains suspended due to communication interruption, uneven stress on equipment components over a prolonged period can lead to structural damage, and falling material could damage surrounding equipment and facilities, posing a serious threat to the lives of nearby workers. Moreover, communication interruptions are frequent in actual production, and existing technologies lack effective solutions for addressing this issue of a suspended bucket due to communication disruptions during unattended operation. This not only affects production efficiency but also significantly increases safety risks, necessitating a new technological solution to address these problems. Summary of the Invention

[0005] The purpose of this invention is to provide a safe handling method for communication interruptions in unattended remote-controlled electric shovels. Addressing the issue of communication interruptions and bucket suspension in mining electric shovels, its working principle is as follows: Communication status is monitored via a communication heartbeat; an emergency stop and brake activation occur upon detection of an anomaly. Multiple sensors are used to perceive information such as bucket position, materials, and obstacles, making decisions based on different operating scenarios to ensure the bucket is safely lowered to the ground at a low speed. Simultaneously, speed and position control deviations are monitored for safety protection. During automatic bucket movement, once communication is restored, the remote operator can interrupt and take over control at any time.

[0006] To achieve the above-mentioned technical objectives, the present invention will adopt the following technical solution: A safety handling method for unattended remotely operated electric shovels after communication interruption includes the following steps: Step S101: Record manual control data according to the set frequency, including real-time input of left and right master commands, position of lifting rope, position of pushing stick, actual position of rotary encoder, and timestamp the recorded data. Step S102: Monitor the communication heartbeat in real time. When communication is interrupted, the emergency stop mechanism is immediately triggered, the input commands of each working mechanism of the electric shovel are cleared, and the brake is engaged. Each working mechanism of the electric shovel includes the lifting mechanism, the pushing mechanism, and the slewing mechanism. Step S103: Enter the bucket safety handling state and control the release of the brakes of all working mechanisms of the electric shovel; Step S104: Determine whether the electric shovel was in the digging process before it stopped: If yes, automatically retrieve the recent operation information according to the manual control data recorded in step S101; if no, proceed to the next step. Step S105: Detect whether there is an obstacle directly below the bucket: If yes, proceed to step S106; if no, proceed to step S107. Step S106: Monitor whether there are obstacles within a set range around the electric shovel bucket. If yes, automatically retrieve recent operation information according to the manual control data recorded in step S101. If no, control the slewing mechanism to rotate at a set speed to the side without obstacles at a certain angle, and then return to step S105 to re-detect whether there are obstacles under the bucket. Step S107: Determine whether the stick position is within the preset horizontal range: If yes, proceed to step S108; if no, further determine whether the stick position is horizontally downward or horizontally upward. If the stick position is horizontally downward, control the lifting mechanism to move upward at a preset lifting speed for a period of time; otherwise, control the lifting mechanism to move downward at a preset lifting speed for a period of time, and then determine again whether the stick position is within the preset horizontal range. Step S108: Determine whether the length of the stick extending from the push pinion exceeds the preset length: If yes, proceed directly to step S109; if no, control the push mechanism to move forward at a preset push speed for a period of time, and then determine again whether the length of the stick extending from the push pinion exceeds the preset length. Step S109: Control the lifting mechanism to lower the bucket at a preset lifting speed until the bucket touches the ground; Step S110: Control all working mechanisms to hold the brakes, shut down the rectifier system, and execute high-voltage shutdown after a preset delay to end the process.

[0007] Preferably, in step S101, when recording manual control data at a set frequency, the set frequency is 100ms; the position of the lifting rope is obtained by collecting data from an absolute encoder installed on the lifting reducer; the position of the pushing bucket is obtained by collecting data from an absolute encoder installed on the pushing reducer; and the actual position of the rotary encoder is obtained by collecting data from an absolute encoder installed at the center of the rotary collector ring.

[0008] Preferably, in step S102, during the real-time monitoring of the communication heartbeat, a threshold for determining communication interruption is set based on an integer multiple of the basic monitoring period, wherein the basic monitoring period of the communication heartbeat is 100ms; when the monitored communication heartbeat delay is greater than the set threshold for determining communication interruption, it indicates that communication has been interrupted.

[0009] Preferably, in step S104, the recent operation information is automatically retrieved according to the manual control data recorded in step S101, specifically referring to retrieving the operation information in the last 3 seconds.

[0010] Preferably, in step S104, the determination of whether the electric shovel is in the digging process before stopping is based on the system parameters before stopping the electric shovel; the system parameters before stopping the electric shovel include the digging / walking mode, the set speed / actual speed / actual torque of the lifting and pushing motors, and the actual speed of the slewing motor.

[0011] Preferably, in step S105, when detecting whether there is an obstacle directly below the bucket, the judgment is made based on the information fed back by the obstacle monitoring sensor installed in front of the top of the driver's cab; the obstacle monitoring sensor includes a lidar and an industrial camera, both of which cover the space below the bucket in their detection areas.

[0012] Preferably, in step S106, when monitoring whether there are obstacles within a set range around the electric shovel bucket, the monitoring is performed based on the information fed back by the 360° coverage achieved by the 120° viewing angle millimeter-wave radar at the four corners of the electric shovel; the slewing mechanism is controlled to rotate at a set speed to the side without obstacles by a certain angle, the set speed specifically refers to 0.1 times the maximum slewing speed; the rotation of a certain angle specifically refers to a slewing adjustment angle of 10°.

[0013] Preferably, in step S107, when determining whether the stick position is within the preset horizontal range, the determination is based on the data fed back by the single-axis inclinometer installed above the saddle of the pushing mechanism; the preset horizontal range specifically refers to the horizontal ±5°; the lifting mechanism moves at a preset speed for a period of time, the preset speed specifically refers to 0.1 times the maximum lifting speed; the movement time specifically refers to an adjustment of 2 seconds.

[0014] Preferably, in step S108, whether the length of the stick extending out of the pushing pinion exceeds a preset length, the preset length specifically refers to three-quarters of the total length of the stick; the pushing mechanism moves forward at a preset pushing speed for a period of time, the preset speed specifically refers to 0.1 times the maximum pushing speed; the movement time specifically refers to 2 seconds.

[0015] Preferably, in step S109, during the lowering of the bucket, the torque of the lifting motor and the stick tilt angle are monitored in real time. When the torque of the lifting motor suddenly decreases while the stick tilt angle remains unchanged, it is determined that the bucket has contacted the ground.

[0016] Another technical objective of the present invention is to provide an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, the computer program being executed to perform the above-described safety handling method for unattended remote-controlled electric shovels after communication interruption.

[0017] Based on the above-mentioned technical objectives, the present invention has the following advantages compared with the prior art: 1. Enhanced safety: Automatic bucket lowering prevents heavy-duty buckets from being suspended in the air for extended periods, reducing structural fatigue and preventing material falling and causing damage to equipment or personnel; 2. Adaptability to unmanned operation: No human intervention is required throughout the process, which enhances the feasibility and reliability of remote control of electric shovels without human intervention, and helps to create unmanned open-pit mining faces; 3. Equipment protection optimization: Low-speed (0.1 times rated speed) bucket dropping and accurate landing judgment (torque + tilt angle dual parameters) improve the safety of automatic operation.

[0018] 4. High flexibility: The communication interruption judgment threshold can be dynamically adjusted according to the communication environment to adapt to the complex working conditions of different mines. At the same time, it supports manual takeover after communication is restored, taking into account both safety and operational flexibility. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a structure for deploying multi-dimensional sensors on an unattended, remotely controlled electric shovel. Figure 2 This is a flowchart of the safety handling method for unattended remote-controlled electric shovels after communication interruption, as described in this invention. In the diagram: 1-Lifting reducer; 2-Center of rotary slip ring; 3-Push reducer; 4-Obstacle monitoring sensor; 5-Millimeter-wave radar; 6-Single-axis inclinometer. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specifically stated, the relative arrangement, expressions, and values ​​of components and steps set forth in these embodiments do not limit the scope of the present invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0021] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used here to describe the spatial positional relationship of a device or feature as shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figure. For example, if the device in the figure is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations). Example 1

[0022] like Figure 2 As shown, the safety handling method for unattended remote-controlled electric shovels after communication interruption according to the present invention, based on multi-scenario intelligent judgment and multi-dimensional safety control strategies, ensures the safe lowering of the bucket, and specifically includes the following steps: Step S101: Record the manual control data according to the set frequency p (the set frequency p can be: p=100ms; or the set recording frequency can be reduced or increased according to the accuracy requirements), including the real-time input of the left and right master commands, the position of the lifting rope, the position of the pushing stick, the actual position of the rotary encoder, and assign a timestamp to the recorded data.

[0023] In this invention, multi-dimensional sensors are deployed on the electric shovel, such as... Figure 1As shown, this enables real-time monitoring of the electric shovel's status and the environment, providing data support for the safe handling of the bucket after communication interruption.

[0024] The status of the electric shovel is determined by the current position of each working mechanism of the electric shovel. Each working mechanism of the electric shovel includes a lifting mechanism, a pushing mechanism, and a slewing mechanism. The lifting mechanism is used to control the raising and lowering of the bucket and includes a lifting motor, a lifting reducer, and a lifting rope. The pushing mechanism is used to control the extension and retraction of the pushing boom and includes a pushing motor, a pushing reducer, and a pushing boom. The slewing mechanism is used to control the rotation of the upper vehicle relative to the lower vehicle and includes a slewing motor.

[0025] The specific hardware configuration of the electric shovel is as follows: A first absolute encoder 1 is installed on the lifting reducer. The position of the lifting rope is calculated by collecting the rotation angle θ1 of the lifting reducer in real time, which can reflect the lifting height of the bucket.

[0026] A second absolute encoder (i.e., a rotary encoder) is installed at the center 2 of the rotary collector ring to monitor the rotation angle θ2 of the upper vehicle relative to the lower vehicle.

[0027] A third absolute encoder 3 is installed on the push reducer. The position of the push boom is calculated by collecting the rotation angle θ3 of the push reducer in real time, which can reflect the extension and retraction state of the boom.

[0028] A single-axis inclinometer 6 is installed above the saddle to monitor the stick inclinometer angle in real time, reflecting the stick's attitude.

[0029] Obstacle detection sensor 4 is installed at the top front of the driver's cab. It is a combination of lidar and industrial camera, with the lidar on top and the industrial camera below. The observation areas of the two overlap and cover the space under the bucket. It is used to detect whether there are obstacles under the bucket, including high-voltage cables at the tail of the electric shovel, large rocks, auxiliary vehicles or equipment. Millimeter-wave radar 5 with a 120° field of view is installed at the left front, left rear, right front and right rear of the electric shovel to form 360° monitoring and perceive the distribution of obstacles around the electric shovel in real time.

[0030] Based on the deployed multi-dimensional sensors, the position of the lifting rope is calculated by collecting data from the first absolute encoder 1 installed on the lifting reducer; the position of the pushing bucket is calculated by collecting data from the third absolute encoder installed on the pushing reducer; and the actual position of the rotary encoder is obtained by collecting data from the second absolute encoder installed at the center of the rotary collector ring.

[0031] The distance traveled by the slewing, pushing, and lifting mechanisms is calculated using both the distance calculated by the motor speed and the distance calculated by the sensor position. Redundancy protection is provided between the two; if the deviation is too large, the automatic movement will stop immediately. Specifically, the distance calculated by the motor speed refers to the distance obtained by integrating the motor speed over time after converting it to the moving mechanism through the transmission ratio. The distance calculated by the sensor position is the difference between the real-time monitoring position and the initial position of the movement.

[0032] Step S102: Monitor the communication heartbeat in real time. When communication is interrupted (communication heartbeat delay > 500ms) and cannot be restored in a short time, the emergency stop mechanism is immediately triggered. The input commands of each working mechanism of the electric shovel are cleared, and the brake is engaged. Each working mechanism of the electric shovel includes the lifting mechanism, the pushing mechanism and the slewing mechanism.

[0033] During the automatic movement of the bucket, once communication is restored, the remote operator can interrupt and take over control at any time.

[0034] In this step, during real-time monitoring of the communication heartbeat, a threshold for determining communication interruption is set based on an integer multiple of the basic monitoring period, where the basic monitoring period is 100ms. In this invention, the set threshold for communication interruption is 5 basic monitoring periods, i.e., the communication heartbeat delay > 500ms. When communication stability is better, the interruption threshold can be adjusted to 6 or more time periods; when communication interference is strong, the interruption threshold can be adjusted to 4 or fewer time periods.

[0035] Step S103: Enter the bucket safety handling state and control the release of the brakes of each working mechanism of the electric shovel.

[0036] Step S104: Determine whether the electric shovel was in the digging process before it stopped. If yes, automatically backtrack the recent operation information (in specific implementation, backtrack for about 3 seconds, which can ensure that about 30 sets of data can be backtracked, taking into account the continuity of electric shovel operation backtracking and the reasonableness of data volume) according to the manual control data recorded in step S101. If no, proceed to the next step.

[0037] In this invention, the system parameters before shutdown (digging / walking mode, set speed / actual speed / actual torque of lifting and pushing motors, and actual speed of slewing motor) are used to determine whether the electric shovel is in the digging process before shutdown.

[0038] Step S105: Detect whether there is an obstacle directly below the bucket: If yes, proceed to step S106; if no, proceed to step S107.

[0039] In this invention, a combination of lidar and industrial camera located at the top front of the driver's cab (covering the space below the bucket) is used to detect whether there are any obstacles (including the high-voltage cable at the tail of the electric shovel).

[0040] Step S106: Monitor whether there are obstacles within a set range around the electric shovel bucket: If so, automatically retrieve recent (in practice, retrieve the last 3 seconds) operation information based on the manual control data recorded in step S101; if not, control the slewing mechanism at a set speed ω0 (in practice, the set speed ω0 is ω0=0.1ω). max ω max The maximum rotation speed of the slewing mechanism is indicated. This speed is a low-speed micro-motion, which allows the system to stop quickly even in the event of a sudden malfunction. The slewing mechanism rotates to the side without obstacles by a certain angle α (in specific implementation, the angle α is set to 10°, which can avoid the impact of large angle adjustments on efficiency and can also effectively change the bucket angle. With the repeated detection mechanism, the lowering position without obstacles can be quickly found). After that, the system returns to step S105 to re-detect whether there are any obstacles under the bucket.

[0041] When implementing this step, the present invention uses millimeter-wave radar with a 120° field of view (360° coverage) at the four corners of the electric shovel to monitor whether there are obstacles within a 5-meter range around the bucket of the electric shovel.

[0042] Step S107: Determine whether the boom position is within a preset horizontal range (in this invention, it is set to horizontal ±5°): If yes, proceed to step S108; if no, further determine whether the boom position is horizontally downward or horizontally upward. If the boom position is horizontally downward, control the lifting mechanism to lift at a preset lifting speed V0 (in specific implementation, the preset lifting speed V0 is set to: V0 = 0.1). V max V max This indicates the maximum lifting speed of the lifting mechanism, which is a low-speed micro-motion, allowing the system to stop quickly even in the event of a sudden malfunction. The system moves upwards for a period of time t0 (in practice, t0 can be 2 seconds, which meets the requirements for attitude adjustment while also ensuring adjustment efficiency through a repeated detection mechanism). Conversely, if the lifting speed is too low, the lifting mechanism is controlled to move downwards at a preset lifting speed V0 for a period of time t0, and then the stick position is checked again to see if it is within the preset horizontal range. The purpose of this step is to prevent the stick from tilting too much, which could cause it to hit the ground or obstacles and malfunction when adjusting the stick position in step S108.

[0043] In this invention, when implementing this step, the monitoring data of the single-axis inclinometer above the saddle is used to determine whether the stick is within the horizontal ±5° range.

[0044] Step S108: Determine whether the length of the stick extending from the push pinion exceeds the preset length. If yes, proceed directly to step S109. If no, control the push mechanism to move forward at a preset push speed (the preset push speed specifically refers to 0.1 times the maximum push speed, which is a low-speed micro-motion, so that the system can stop quickly even in the event of a sudden failure) for a period of time (the movement time specifically refers to 2 seconds, which can meet the needs of adjusting the posture and, together with the repeated detection mechanism, ensure the adjustment efficiency). Then, determine again whether the length of the stick extending from the push pinion exceeds the preset length.

[0045] In this invention, during this step, based on the absolute encoder data of the push reducer, it is determined whether the length of the stick extending beyond the push pinion exceeds a preset length L0. The preset length L0 is set as: L0 = 3 / 4 * L, where L represents the total length of the stick. The preset length L0 ensures that the stick extends a sufficient distance, preventing the bucket from colliding with the electric shovel or failing to land horizontally as required when lowering the bucket in step S109 due to an insufficient rotation radius.

[0046] Step S109: Control the lifting mechanism to lower the bucket at a preset lifting speed V0 until the bucket touches the ground.

[0047] In this invention, during this step, the hoisting motor torque and the stick tilt angle are monitored in real time: when the hoisting motor torque suddenly decreases while the stick tilt angle remains unchanged, it is determined that the bucket has contacted the ground.

[0048] Step S110: Control all working mechanisms to hold the brakes, shut down the rectifier system, and execute high-voltage shutdown after a preset delay to end the process.

[0049] This solution achieves automatic and safe landing of heavy-duty buckets in unattended scenarios when communication is interrupted through multi-sensor fusion perception, multi-dimensional status judgment, and tiered safety operation, effectively avoiding the risks of equipment damage and safety accidents. Example 2

[0050] The present invention also provides a storage medium, wherein the computer program stored in the storage medium, when running, executes the above-described safety handling method after communication interruption of the unattended remote-controlled electric shovel. Example 3

[0051] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the above-described safety handling method for unattended remote-controlled electric shovels after communication interruption through the computer program.

[0052] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0053] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0054] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0055] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0056] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0057] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A safety handling method for unattended remote-controlled electric shovels after communication interruption, characterized in that, Includes the following steps: Step S101: Record manual control data according to the set frequency, including real-time input of left and right master commands, position of lifting rope, position of pushing stick, actual position of rotary encoder, and timestamp the recorded data. Step S102: Monitor the communication heartbeat in real time. When communication is interrupted, the emergency stop mechanism is immediately triggered, the input commands of each working mechanism of the electric shovel are cleared, and the brake is engaged. Each working mechanism of the electric shovel includes the lifting mechanism, the pushing mechanism, and the slewing mechanism. Step S103: Enter the bucket safety handling state and control the release of the brakes of all working mechanisms of the electric shovel; Step S104: Determine whether the electric shovel was in the digging process before it stopped: If yes, automatically retrieve the recent operation information according to the manual control data recorded in step S101; if no, proceed to the next step. Step S105: Detect whether there is an obstacle directly below the bucket: If yes, proceed to step S106; if no, proceed to step S107. Step S106: Monitor whether there are obstacles within a set range around the electric shovel bucket. If yes, automatically retrieve recent operation information according to the manual control data recorded in step S101. If no, control the slewing mechanism to rotate at a set speed to the side without obstacles at a certain angle, and then return to step S105 to re-detect whether there are obstacles under the bucket. Step S107: Determine whether the stick position is within the preset horizontal range: If yes, proceed to step S108; if no, further determine whether the stick position is horizontally downward or horizontally upward. If the stick position is horizontally downward, control the lifting mechanism to move upward at a preset lifting speed for a period of time; otherwise, control the lifting mechanism to move downward at a preset lifting speed for a period of time, and then determine again whether the stick position is within the preset horizontal range. Step S108: Determine whether the length of the stick extending from the push pinion exceeds the preset length: If yes, proceed directly to step S109; if no, control the push mechanism to move forward at a preset push speed for a period of time, and then determine again whether the length of the stick extending from the push pinion exceeds the preset length. Step S109: Control the lifting mechanism to lower the bucket at a preset lifting speed until the bucket touches the ground; Step S110: Control all working mechanisms to hold the brakes, shut down the rectifier system, and execute high-voltage shutdown after a preset delay to end the process.

2. The safety handling method for unattended remote-controlled electric shovels after communication interruption according to claim 1, characterized in that, In step S101, when recording manual control data at a set frequency of 100ms, the position of the lifting rope is obtained by collecting data from an absolute encoder installed on the lifting reducer; the position of the pusher stick is obtained by collecting data from an absolute encoder installed on the pusher reducer; and the actual position of the rotary encoder is obtained by collecting data from an absolute encoder installed at the center of the rotary collector ring.

3. The safety handling method for unattended remote-controlled electric shovels after communication interruption according to claim 1, characterized in that, In step S102, during the real-time monitoring of the communication heartbeat, a threshold for determining communication interruption is set based on an integer multiple of the basic monitoring period, wherein the basic monitoring period of the communication heartbeat is 100ms; when the monitored communication heartbeat delay is greater than the set threshold for determining communication interruption, it indicates that communication has been interrupted.

4. The safety handling method for unattended remote-controlled electric shovels after communication interruption according to claim 1, characterized in that, In step S104, the recent operation information is automatically retrieved according to the manual control data recorded in step S101, specifically referring to the operation information in the last 3 seconds.

5. The safety handling method for unattended remote-controlled electric shovels after communication interruption according to claim 1, characterized in that, In step S104, the determination of whether the electric shovel is in the digging process before it stops is based on the system parameters before the electric shovel stops. The system parameters before the electric shovel stops include the digging / traveling mode, the set speed / actual speed / actual torque of the lifting and pushing motors, and the actual speed of the slewing motor. In step S105, when detecting whether there is an obstacle directly below the bucket, the judgment is made based on the information fed back by the obstacle monitoring sensor installed in front of the top of the driver's cab. Obstacle detection sensors include lidar and industrial cameras, both of which cover the space under the bucket.

6. The safety handling method for unattended remote-controlled electric shovels after communication interruption according to claim 1, characterized in that, In step S106, when monitoring whether there are obstacles within a set range around the electric shovel bucket, the monitoring is performed based on the information fed back by the 120° viewing angle millimeter-wave radar at the four corners of the electric shovel to achieve 360° coverage; the slewing mechanism is controlled to rotate at a set speed to the side without obstacles by a certain angle, the set speed specifically refers to 0.1 times the maximum slewing speed; the rotation of a certain angle specifically refers to a slewing adjustment angle of 10°.

7. The safety handling method for unattended remote-controlled electric shovels after communication interruption according to claim 1, characterized in that, In step S107, when determining whether the stick position is within the preset horizontal range, the data is based on the data fed back by the single-axis inclinometer installed above the saddle of the pushing mechanism; the preset horizontal range specifically refers to the horizontal ±5°; the lifting mechanism moves at a preset speed for a period of time, the preset speed specifically refers to 0.1 times the maximum lifting speed; the movement time specifically refers to an adjustment of 2 seconds.

8. The safety handling method for unattended remote-controlled electric shovels after communication interruption according to claim 1, characterized in that, In step S108, it is determined whether the length of the stick extending out of the pushing pinion exceeds the preset length, which specifically refers to three-quarters of the total length of the stick; the pushing mechanism moves forward at a preset pushing speed for a certain period of time, which specifically refers to 0.1 times the maximum pushing speed; the movement time specifically refers to 2 seconds.

9. The safety handling method for unattended remote-controlled electric shovels after communication interruption according to claim 1, characterized in that, In step S109, during the lowering of the bucket, the hoisting motor torque and stick tilt angle are monitored in real time. When the hoisting motor torque suddenly decreases while the stick tilt angle remains unchanged, it is determined that the bucket has contacted the ground.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, The computer program is executed to perform the safety handling method for unattended remote-controlled electric shovels after communication interruption as described in any one of claims 1 to 9.

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