Unattended control method for dumping plough

Abstract

The invention discloses an unattended control method for a dumping plough, and belongs to the technical field of ore extraction. The method comprises the following steps: after receiving a current dumping task, determining the position and pose of a dumping machine; establishing a three-dimensional model of the waste dump according to the three-dimensional shape of the material pile; and extracting the contour features of the dumping site, calculating the rotation angle of the dumping arm of the dumping machine corresponding to the dumping boundary, comparing the rotation angle with the rotation angle obtained by measurement, and when the movement position of the dumping arm is close to the position corresponding to the dumping boundary, controlling the dumping arm to automatically move towards the other direction for the next operation action. The whole process is automatically controlled, the labor intensity of workers is reduced, the working efficiency is improved, and the personal safety of the workers is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of ore mining, and in particular relates to an unattended control method for a soil dumper. Background Art

[0002] The spoiler is a key equipment in the stripping operation of open-pit mines. In the stripping operation of open-pit mines, materials are collected by electric shovels and single-bucket trucks or bucket wheel excavators, and transported by belt conveyors. The spoiler is located at the end of the stripping and transportation system. The stripped soil and rocks are unloaded to the receiving arm through the unloading tail car, and then transported to the discharging arm through the belt conveyor on the receiving arm, and finally discharged to the spoil dump through the belt conveyor on the discharging arm. The spoiler operator operates in the control room on the spoiler, and the on-site noise and dust pollution, the working environment is harsh, and it is not conducive to health.

[0003] At present, the soil discharge operation of the soil discharger is operated by workers in the control room on the soil discharger. The on-site working conditions are relatively complex and harsh, the manual labor intensity is high, the work efficiency is low, the safety is poor, and the occupational hazards are great. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide an unattended control method for a soil dumper, which solves the problem that the soil dumping operation of the soil dumper must be controlled by workers on the soil dumper, the operating environment is harsh and the safety of the workers cannot be guaranteed, and the work efficiency is low.

[0005] The technical solution adopted by the invention is: an unattended control method for a soil discharger, and its technical key points are, including the following steps: after receiving the current soil discharge task, determining the position and posture of the soil discharger; establishing a three-dimensional model of the soil discharge yard according to the three-dimensional shape of the material pile; extracting the contour features of the soil discharge yard, and calculating the rotation angle of the discharge arm of the soil discharger corresponding to the soil discharge boundary, and comparing the rotation angle with the rotation angle obtained by measurement. When the moving position of the discharge arm is close to the position corresponding to the soil discharge boundary, the discharge arm is controlled to automatically move in another direction to perform the next operation.

[0006] Furthermore, the method for determining the position of the spoil dumper is as follows: a positioning device is installed on the crawler bridge of the spoil dumper, and after the positioning device receives the GNSS satellite signal and the differential correction data sent by the base station set up in the spoil dump, it performs positioning calculation to obtain the position information of the spoil dumper.

[0007] Furthermore, the position of the soil discharger includes a rotation angle of the discharge arm and a pitch angle of the discharge arm.

[0008] Furthermore, the method for determining the rotation angle of the discharge arm is as follows: taking the direction of the discharge arm and the track of the soil discharger unloading trolley as 0°, an electronic tag for collecting the absolute rotation angle of the discharge arm is installed every 90 degrees at the fixed position of the rotating platform of each soil discharger; the position coincident with the track of the soil discharger unloading trolley is calibrated as the reference zero point of the encoder, and the encoder calculates the actual angle when the soil discharger is rotating; when the discharge arm of the soil discharger rotates, each time it passes an electronic tag, the absolute position information of the electronic tag is read, the absolute angle of the current rotation of the soil discharger is obtained, and compared with the position information calculated by the encoder, the final rotation angle of the discharge arm is obtained.

[0009] Furthermore, the determining of the three-dimensional shape of the material pile and establishing the three-dimensional model of the spoil dump refers to obtaining point cloud data of the material pile of the spoil dump by scanning, and regenerating the three-dimensional model of the material pile of the spoil dump using the obtained point cloud data.

[0010] Furthermore, the extraction of the dumping area contour features refers to detecting the dumping area boundary through the dumping machine protection strategy and the boundary recognition strategy, and extracting the dumping area contour features using the point cloud adaptive variable threshold segmentation algorithm.

[0011] Furthermore, the soil dumper protection strategy refers to the first layer of mechanical protection; the second layer of soft limit protection; the third layer of ultrasonic protection; and the fourth layer of system protection.

[0012] Furthermore, the automatic soil discharge strategy includes a rotary soil discharge method and a fixed-point soil discharge method. The fixed-point soil discharge method is used for a material pile that requires a regular shape, and the rotary soil discharge method is used for a material pile that has an irregular shape.

[0013] The beneficial effects of the present invention are as follows: the unattended control method of the soil dumper determines the position and posture of the soil dumper after receiving the current soil dumping task; establishes a three-dimensional model of the soil dumping field according to the three-dimensional shape of the material pile; extracts the contour features of the soil dumping field, calculates the rotation angle of the soil dumper discharge arm corresponding to the soil dumping boundary, and compares the rotation angle with the rotation angle obtained by measurement. When the displacement position of the discharge arm approaches the position corresponding to the soil dumping boundary, the discharge arm is controlled to automatically move in another direction to perform the next operation. The whole process realizes automated control, reduces the intensity of manual labor, improves work efficiency, and ensures the personal safety of workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1This is a principle diagram of the fixed-point soil discharge method in an embodiment of the present invention; Figure 2 Schematic diagram of the rotary soil discharge method in an embodiment of the present invention; Figure 3 The present invention is a flowchart of an unattended control method for a soil dumper in an embodiment of the present invention. DETAILED DESCRIPTION

[0016] To make the above-mentioned objects, features and advantages of the present invention more obvious, the following is a brief description of the present invention in conjunction with the attached Figure 1-Figure 3 The present invention is further described in detail with specific implementation modes.

[0017] The unattended control system of the soil dumper adopted in this embodiment includes: a positioning system, a three-dimensional scanning system, an anti-collision system, a control system, etc. Among them, the three-dimensional scanning system of the soil dumper includes a laser radar scanner and a three-dimensional scanning server. The laser radar scanner is installed at the head of the material dumping arm, and is installed horizontally and symmetrically parallel to the material dumping arm on the left and right to obtain the point cloud data of the material pile in the soil dumping yard. The three-dimensional scanning server is installed in the remote control room of the soil dumper to process the returned point cloud data and generate a three-dimensional model of the soil dumping yard.

[0018] The anti-collision system of the soil discharging machine has three sets of ultrasonic distance measurement anti-collision devices installed on both sides of the discharging arm of each soil discharging machine. The anti-collision distance is adjustable to ensure that the discharging arm does not collide with the material piles on both sides and other obstacles during the soil discharging operation. A set of radar material level detection device is installed at the material outlet of the discharging arm head of each soil discharging machine for material height control to prevent the discharging arm from colliding with the soil pile. Two ultrasonic distance meters are installed in front and behind the lower crawler of the soil discharging machine to monitor obstacles when the soil discharging machine is moving.

[0019] The control system includes a PLC controller, a host computer and server, an industrial switch, and a wireless communication device. The PLC controller is used to collect data of the soil dumper and control the movement of the soil dumper. The host computer and server are installed in the remote control room of the soil dumper to display the operating parameters of the soil dumper, fault alarm, equipment control, video monitoring, preparation of production plans, display of production reports, etc., and send control instructions to the PLC controller to control the soil dumper to realize unattended soil dumping operations. The industrial switch and wireless communication device are used to communicate between the PLC controller and the host computer server.

[0020] The unattended control method of a soil dumper of this embodiment comprises the following steps: Step 1: After receiving the soil dumping task, determine the position and posture of the soil dumper. Measure the relative walking position of the soil dumper to the soil dumping field, the posture of the soil dumper including the rotation angle of the dumping arm and the pitch angle of the dumping arm. The data accuracy of these three action mechanisms is the key technology for the fully automatic unmanned operation of the soil dumper. The precision and accuracy of positioning seriously affect the efficiency and safety of unmanned work.

[0021] Step 1.1: Determine the location of the dumper.

[0022] A unified three-dimensional space coordinate system is established for the dumping site, dumper, and stockpile. The X direction of the coordinate system is the track direction of the dumper unloading trolley, the Y direction is the direction perpendicular to the track of the dumper unloading trolley, and the Z direction is the height direction of the stockpile. The walking position accuracy is plus or minus 0.05 meters, and the rotation and pitch angle accuracy is plus or minus 0.01 degrees.

[0023] An RTK base station is set up in the spoil dump and an RTK high-precision positioning module is installed on the crawler bridge of the spoil dumper.

[0024] The base station is located at a known position and sends correction data to the high-precision positioning module. The high-precision positioning module receives the correction data during movement and performs real-time positioning.

[0025] After receiving the GNSS satellite signal and the differential correction data sent by the base station, the high-precision positioning module combines the two to perform accurate positioning calculations to obtain high-precision location information of the earthmoving machine.

[0026] Step 1.2, determining the rotation angle of the discharge arm of the soil discharger, includes the following steps: Step 1.2.1: Install a set of driven rotary positioning device on the rotary mechanism of each soil discharger. The rotary positioning device includes encoders and gears. The gears in the driven rotary device equipped with the encoder mesh with the gears of the rotary mechanism body to achieve synchronous rotation, thereby measuring the rotation angle of the discharge arm.

[0027] Step 1.2.2: Install an electronic tag every 90 degrees at the fixed position of the rotating platform of each soil spreader. Take the direction of the discharge arm and the track of the soil spreader unloading trolley as 0°, and arrange the electronic tags at the corresponding positions of -90°, -45°, 0°, 45°, and 90° respectively. Install a total of 5 tags for absolute angle coding.

[0028] Step 1.2.3: During the rotary positioning process, the reference zero point of the encoder must first be calibrated at the position that coincides with the track of the soil spreader unloading trolley. During the rotation of the soil spreader, the current data of the encoder is continuously obtained through the positioning system acquisition terminal, and the current position of the soil spreader is calculated by comparing it with the reference zero point data.

[0029] Step 1.2.4: When the discharging arm of the earth-spreader rotates, each time it passes an electronic tag, it reads the absolute position information of the tag, obtains the current absolute rotation angle of the earth-spreader, compares it with the position information calculated by the encoder in step 1.2.3, and performs position correction to reduce the positioning error caused by excessive rotation angle and improve real-time positioning accuracy.

[0030] Step 1.3, determining the pitch angle of the discharge arm of the soil discharger, includes the following steps: Step 1.3.1: The pitch positioning of the discharge arm of the earth-spreader adopts a high-precision inclinometer designed based on gravity sensing technology, and one set is installed on the inner side of the tail of the discharge arm. The detection accuracy reaches 0.01°, and the angle signal is sent to the PLC controller through communication.

[0031] Step 1.3.2: The high-precision inclinometer is based on gravity sensing and outputs data with the horizontal 0° as the absolute position. During the pitch process, it outputs a 4-20ma signal in real time as the angle changes, and determines the real-time pitch angle of the discharge arm through data conversion.

[0032] Step 2: Determine the 3D shape of the material pile and establish a 3D model of the dumping site; extract the contour features of the dumping site through the point cloud adaptive variable threshold segmentation algorithm, and calculate the rotation angle of the dumping arm of the dumper corresponding to the dumping boundary.

[0033] Step 2.1: The 3D laser scanning system obtains point cloud data of the spoil pile by scanning, and sends the obtained point cloud data to the 3D scanning server to generate a 3D model of the spoil pile.

[0034] The 3D laser scanning system includes a laser radar scanner and a 3D scanning server. The laser radar scanner is installed on the head of the discharge arm and is installed horizontally and symmetrically on the left and right sides of the discharge arm. During the operation, the discharger automatically performs a 3D laser scan on the outer contour of the operating material pile to obtain the point cloud data of the discharge yard pile. The point cloud data is transmitted to the 3D scanning server via Ethernet. The 3D scanning server is used to process the returned point cloud data and generate a 3D model of the discharge yard. The 3D model supports operations such as rotation, scaling, and translation, and can dynamically update the 3D model during discharge. The operator can query the position coordinate data at any point on the 3D model. The 3D model can display each discharge area and dynamically display it on the upper computer screen.

[0035] Step 2.2: The control server analyzes the three-dimensional model of the spoil dump, generates the action instructions of the spoil dump according to the set algorithm strategy and the equipment parameter data of the spoil dump, and sends the control instructions to the PLC controller; wherein the algorithm strategy includes: spoil dump protection strategy, boundary recognition strategy and automated spoil dumping strategy.

[0036] Step 2.2.1: The spoiler protection strategy is as follows: The first level of protection detection is mechanical protection, which ensures that the soil discharger meets the protection requirements of the mechanical performance of the equipment during routine operation through the mechanical limit switches of the slewing mechanism and pitching mechanism, such as slewing limit / limit, pitching limit / limit, and pull rope switches on both sides of the discharge arm.

[0037] The second level of protection is soft limit protection. By adding walking, slewing and pitching soft protection functions in the program, the position information of each mechanism collected by the positioning system is compared with the physical mechanical limit position. When each mechanism exceeds the position of its physical limit, the corresponding dumper action automatically stops operating (stops the operation of various mechanisms such as walking, slewing and pitching), and gives an audible and visual alarm.

[0038] The third layer is ultrasonic protection for protection detection. Ultrasonic wave is used to detect material piles or other foreign objects within 0-6 meters around the earth-discharging machine and the discharge arm in real time. When any foreign objects are detected, the machine slows down in advance. The ultrasonic detection device is installed with anti-collision alarm for any action of the discharge arm to ensure that the automatic protection requirements of the earth-discharging machine are met during operation.

[0039] The fourth level of protection is system protection. The system occupies the space of each material pile on the spoil yard according to its outer contour. The space occupied by the material pile is automatically set as a restricted area. The system detects the position of the discharge arm in the space in real time. Once it approaches the restricted area, the discharge arm will stop moving and provide an alarm.

[0040] Step 2.2.2: The boundary identification strategy process is: the boundary of the soil dumping area needs to be automatically detected during the soil dumping operation, and the function of automatic rotation to the boundary needs to be realized. The specific method of realizing the automatic soil dumping boundary detection and automatic rotation function in the PLC control system is: extracting contour features through the point cloud adaptive variable threshold segmentation algorithm, calculating the rotation angle corresponding to the soil dumping boundary, and sending the data to the PLC controller in real time. The PLC controller obtains the spatial position coordinates of the soil dumping machine's discharge arm in real time through the soil dumping machine positioning system, and compares it with the boundary coordinate data sent by the three-dimensional scanning system during the soil dumping operation. When the discharge arm moves close to the position corresponding to the soil dumping boundary, the discharge arm automatically moves in the other direction to prepare for the next operation.

[0041] Step 3: The soil spreader PLC control system instructs the soil spreader to perform automated material discharge operations according to the control instructions, and feeds back real-time equipment data to the control server.

[0042] Step 3.1: Automated soil discharge strategy. For small-sized material piles that require regular shapes, the fixed-point discharge method can achieve higher operation stability. For large or irregular-shaped material piles, the rotary discharge method can better adapt to the changes in the material pile and achieve continuous and efficient soil discharge operations.

[0043] (1) Fixed-point soil discharge method. During the automatic soil discharge process, the soil discharger does not move, and the discharge arm is fixed at a certain height for soil discharge. The height of the material pile is set within the operating range allowed by the soil discharger. In order to reduce dust during the soil discharge process, the height of the discharge arm is generally fixed at 4m from the surface of the material pile. When the material pile is 1m away from the position of the discharge arm, the discharge arm is controlled to move up 3m until the height of the material pile at that point reaches the predetermined height. The discharge arm rotates an angle to discharge soil at the second point. After the soil discharge is completed within the effective rotation range, the soil discharger retreats 2m and performs the next rotation of fixed-point soil discharge until the soil discharge is completed. Figure 1 As shown, the order of discharging soil at fixed points is to discharge soil at fixed points in sequence according to the numerical order shown in the figure, and after discharging the first layer, continue to discharge the second layer until 64 ends.

[0044] (2) Rotary soil discharge method. During the automatic soil discharge process, the stacker-reclaimer does not move, the discharge arm is fixed at a certain height, and it rotates left and right within the effective rotation range to discharge soil. The height control of soil discharge is the same as that of fixed-point soil discharge. When the pile height reaches the predetermined height, the truck retreats 2m and then performs the second rotation of soil discharge until the soil discharge is completed. Figure 2 As shown, after the soil discharging machine discharges to the upper boundary number 1, the soil discharging machine retreats to the lower boundary number 1 and retreats 2m, and starts discharging from the boundary shown by the lower number 2 until it reaches the boundary shown by the upper number 2, and then retreats 2m, discharging reciprocatingly in numerical order.

[0045] Step 3.2: Feedback the equipment data such as the position and operating parameters of the on-site dumper to the control server for the next operation.

[0046] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An unattended control method for a soil dumper, characterized in that: The method includes the following steps: after receiving the current soil discharge task, determining the position and posture of the soil discharger; establishing a three-dimensional model of the soil discharge yard according to the three-dimensional shape of the material pile; extracting the contour features of the soil discharge yard, calculating the rotation angle of the discharge arm of the soil discharger corresponding to the soil discharge boundary, and comparing the rotation angle with the measured rotation angle. When the moving position of the discharge arm is close to the position corresponding to the soil discharge boundary, the discharge arm is controlled to automatically move in another direction to perform the next operation.

2. The unattended control method for a soil dumper according to claim 1, characterized in that: The method for determining the position of the soil dumper is as follows: a positioning device is installed on the crawler bridge of the soil dumper, and after receiving the GNSS satellite signal and the differential correction data sent by the base station set up in the soil dumping field, the positioning device performs positioning calculation to obtain the position information of the soil dumper.

3. The unattended control method for a soil dumper according to claim 1, characterized in that: The position of the soil dumper includes the rotation angle of the dumping arm and the pitch angle of the dumping arm.

4. The unattended control method for a soil dumper according to claim 3, characterized in that: The method for determining the rotation angle of the discharge arm is as follows: taking the direction of the discharge arm and the track of the soil discharger unloading trolley as 0°, an electronic tag for collecting the absolute rotation angle of the discharge arm is installed every 90 degrees at the fixed position of the rotating platform of each soil discharger; the position coincident with the track of the soil discharger unloading trolley is calibrated as the reference zero point of the encoder, and the encoder calculates the actual angle during the rotation of the soil discharger; when the discharge arm of the soil discharger rotates, each time it passes an electronic tag, the absolute position information of the electronic tag is read to obtain the absolute angle of the current rotation of the soil discharger, which is compared with the position information calculated by the encoder to obtain the final rotation angle of the discharge arm.

5. The unattended control method for a soil dumper according to claim 1, characterized in that: The determining of the three-dimensional shape of the material pile and establishing the three-dimensional model of the spoil dump refers to obtaining point cloud data of the material pile of the spoil dump by scanning, and regenerating the three-dimensional model of the material pile of the spoil dump by using the obtained point cloud data.

6. The unattended control method for a soil dumper according to claim 1, characterized in that: The extraction of the dumping site contour features refers to detecting the dumping area boundary through the dumping machine protection strategy and the boundary recognition strategy, and extracting the dumping site contour features using the point cloud adaptive variable threshold segmentation algorithm.

7. The unattended control method for a soil dumper according to claim 6, characterized in that: The protection strategy for the earthmoving machine is as follows: the first layer is mechanical protection; the second layer is soft limit protection; the third layer is ultrasonic protection; and the fourth layer is system protection.

8. The unattended control method for a soil dumper according to claim 1, characterized in that: Automatic soil discharge strategies include rotary soil discharge method and fixed-point soil discharge method. The fixed-point soil discharge method is used for material piles that require regular shapes, and the rotary soil discharge method is used for material piles with irregular shapes.

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