Automatic slagging control method for a slagging vehicle

Abstract

The application discloses an automatic slag scooping control method of a slag scooping vehicle, and the control method comprises the following steps: in step one, a control system drives a height adjusting assembly and a pitch angle adjusting assembly to jointly control a slag scooping shovel to reach a predetermined depth and angle according to a target working depth; in step two, in a slag scooping stroke, the control system takes the displacement of the height adjusting hydraulic cylinder as a main control variable, takes the displacement of the pitch angle adjusting hydraulic cylinder as a driven compensation variable, divides a working process into three automatic stages of cutting in, scooping material and lifting, and automatically completes originally complicated compound actions by the system, so that the working efficiency is greatly improved; and a real-time proportional linkage model LP=k(θ)×LH+b of the height adjusting hydraulic cylinder and the pitch angle adjusting hydraulic cylinder is established.

Description

Technical Field

[0001] This invention relates to an automatic muck-loading control method for a muck-loading truck, belonging to the field of muck-loading trucks. Background Technology

[0002] Slag loaders are key equipment used in metallurgical, mining, and tunnel engineering for cleaning waste slag and mineral materials. Existing slag loaders typically employ multi-section robotic arms in conjunction with hydraulic cylinders to drive the slag-loading blades to complete the cutting, shoveling, and lifting actions. However, in actual operation, existing slag loading control technology still has the following shortcomings:

[0003] Because the adjustment mechanism of the slag shovel is usually a non-linear multi-bar hinge structure, when the hydraulic cylinder drives the connecting rod to rotate in a circle, the movement trajectory of the shovel tip is arc-shaped. To achieve horizontal straight material removal, the operator needs to manually compensate for the pitch angle and height at extremely high frequencies, which can easily lead to "grounding" or "shovel drifting" phenomena, resulting in uneven cleaning of the bottom of the slag pit. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an automatic muck-loading control method for a muck-loading truck to solve the problem.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an automatic muck-loading control method for a muck-loading truck, wherein the muck-loading truck comprises:

[0006] Slag shovel;

[0007] Connecting plate;

[0008] Rotating platform; pitch angle adjustment assembly for adjusting the angle of the shovel relative to the ground; including pitch angle adjustment rod, first height adjustment rod, and pitch angle adjustment hydraulic cylinder;

[0009] A height adjustment assembly for adjusting the height of the shovel above the ground; including a second height adjustment rod and a height adjustment hydraulic cylinder;

[0010] Control system;

[0011] The control method includes:

[0012] Step 1: The control system drives the height adjustment component and the pitch angle adjustment component to jointly control the tip of the shovel to reach the predetermined depth and angle according to the target working depth.

[0013] Step two: During the slag removal stroke, the control system uses the displacement of the height-adjusting hydraulic cylinder as the primary control variable and the displacement of the pitch-angle-adjusting hydraulic cylinder as the secondary compensation variable. A proportional linkage model for the extension and retraction of the two sets of hydraulic cylinders is established in real time: LP = k(θ) × LH + b, where k(θ) = k0 + α × sin(θ). Here, LP is the real-time total length of the pitch-angle-adjusting hydraulic cylinder, LH is the real-time total length of the height-adjusting hydraulic cylinder, k(θ) is the transmission ratio coefficient, and b is the compensation constant in the initial operating state. k0 is a fixed value within ±10° of the horizontal line, and α is the transmission ratio correction coefficient. When 10° > θ... When θ > -10°, α = 0; when 20° > θ ≥ 10°, or -10° ≥ θ > -20°, α = 0.12k0; when 35° > θ ≥ 20°, or -20° ≥ θ > -35°, α = 0.20k0; the horizontal direction of the rotating platform is taken as the X-axis, the direction of the slag shovel is positive, and the direction perpendicular to the horizontal plane and upward is taken as the Y-axis; where θ is the instantaneous tilt angle of the second height adjustment rod relative to the X-axis; by utilizing the geometric constraint relationship between the first height adjustment rod and the second height adjustment rod, the height fluctuation of the slag shovel during the backward movement is dynamically offset, so that the tip of the slag shovel moves smoothly along a predetermined horizontal straight line or a preset curved trajectory;

[0014] Step 3: When the operation is detected to be completed or the load reaches the preset threshold, the control system drives the height adjustment hydraulic cylinder to extend forward, causing the second height adjustment rod to rotate upward to lift the slag shovel as a whole; at the same time, the control system controls the pitch angle adjustment hydraulic cylinder to retract at a response speed higher than that of the height adjustment, so that the slag shovel flips upward around its connection point with the first height adjustment rod, forming a closed bearing posture to prevent waste slag from falling off.

[0015] Preferably, in step two, the control system establishes the proportional linkage model based on a preset coordinate system; wherein, the hinge point A between the height adjustment hydraulic cylinder and the rotating platform in the height adjustment component is taken as the coordinate origin (0,0); the horizontal direction of the rotating platform is taken as the X-axis, the direction of the slag shovel is positive, and the direction perpendicular to the horizontal plane upwards is taken as the Y-axis; wherein:

[0016] The coordinates of hinge point B (XB, YB): that is, the coordinates of the hinge point between the second height adjustment rod and the rotating platform;

[0017] The coordinates (XC, YC) of hinge point C: that is, the coordinates of the hinge point between the pitch angle adjusting hydraulic cylinder and the rotating platform.

[0018] Preferably, the control system acquires the instantaneous tilt angle θ of the second height adjustment rod relative to the X-axis in real time.

[0019] Preferably, in step one, the control system first obtains the target cutting depth H0, calculates the required total length LH0 of the height adjustment hydraulic cylinder, and then extends or retracts according to the current length of the height adjustment hydraulic cylinder; when the height adjustment hydraulic cylinder moves to 0.8×LH0, the pitch angle adjustment hydraulic cylinder is triggered to move synchronously, so that the shovel accurately forms a cutting angle when it reaches the target depth.

[0020] Preferably, in step two, the control system corrects the value of b in real time according to the initial height of the shovel, so as to ensure that the parallelism error between the shovel tip movement trajectory and the ground is controlled within ±2%.

[0021] Preferably, in step two, the control system monitors the displacement change ΔLH of the height adjustment hydraulic cylinder at a fixed frequency, and calculates the target displacement LP=k(θ)×(LH+ΔLH)+b of the pitch angle adjustment hydraulic cylinder in real time, so as to realize the synchronous linkage between the height adjustment hydraulic cylinder and the pitch angle adjustment hydraulic cylinder.

[0022] Preferably, in step three, the loading threshold PL is set as follows: PL = Pm + ΔP, where Pm is the hydraulic chamber pressure when the slag shovel is unloaded, and ΔP is the pressure increment preset according to the density of the waste slag to be processed; when the pressure value collected by the control system for 0.5 seconds is greater than PL, the lifting action is automatically triggered.

[0023] Preferably, during the lifting process in step three, the retraction speed of the pitch angle adjusting hydraulic cylinder is faster than that of the height adjusting hydraulic cylinder, causing the connecting plate to drive the slag scraper to flip upward to an elevation angle greater than 45° relative to the ground.

[0024] Preferably, the control system provides a manual and automatic switching mode; in automatic mode, the control system reads the operation sequence table pre-stored in the PLC memory and automatically cycles through the cutting, unloading and lifting stages until the operation completion instruction is received.

[0025] Beneficial effects

[0026] This invention divides the operation process into three automated stages: cutting, material removal, and lifting. This allows the system to automatically complete the originally complex compound actions, significantly improving work efficiency. By establishing a real-time proportional linkage model LP=k(θ)×LH+b for the height adjustment hydraulic cylinder and the pitch angle adjustment hydraulic cylinder, the control system can automatically compensate for the vertical displacement component generated by the multi-bar mechanism in the circular motion. In particular, the introduction of a dynamic transmission ratio correction coefficient α based on sin(θ) effectively offsets the height fluctuation caused by nonlinear geometric constraints, keeping the parallelism error between the slag removal shovel tip trajectory and the ground within ±2%, thus ensuring the flatness of the bottom of the slag pit after cleaning. Attached Figure Description

[0027] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0028] Figure 1 A schematic diagram of the telescopic end of the height-adjusting hydraulic cylinder before and after extension and retraction is shown in an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the telescopic end of the pitch angle adjusting hydraulic cylinder before and after extension and retraction is shown in an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the slag scraper and connecting plate of the present invention is shown. Detailed Implementation

[0031] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0032] Please see Figures 1-3 This invention provides a technical solution for an automatic muck-loading control method for a muck-loading truck: the muck-loading shovel 30 is installed on the muck-loading truck. In one embodiment, the muck-loading truck adopts a muck-loading shovel adjustment device and muck-loading truck with application number 202522736560.X. The muck-loading truck includes a muck-loading shovel 30, a connecting plate 12, a rotating platform 11, a pitch angle adjustment component, a height adjustment component, and a control system. The pitch angle adjustment component is used to adjust the angle of the muck-loading shovel 30 relative to the ground, and includes a pitch angle adjustment rod 13, a first height adjustment rod 14, and a pitch angle adjustment hydraulic cylinder 16. The height adjustment component is used to adjust the height of the muck-loading shovel 30 relative to the ground, and includes a second height adjustment rod 15 and a height adjustment hydraulic cylinder 17.

[0033] In this embodiment, the slag removal operation is divided into a cutting stage, a material removal stage, and a hoisting stage. The specific control methods include:

[0034] Step 1: The control system first acquires the target cutting depth H0 and calculates the target extension LH0 of the height-adjusting hydraulic cylinder 17. Based on the target working depth, the control system drives the height-adjusting hydraulic cylinder 17 to extend forward, causing the second height-adjusting rod 15 to rotate upwards around its hinge point with the rotating platform 11. Preferably, when the height-adjusting hydraulic cylinder 17 moves to 0.8 × LH0, the pitch angle-adjusting hydraulic cylinder 16 is triggered to move synchronously. The control system outputs an angle offset command matching the height change, driving the pitch angle-adjusting hydraulic cylinder 16 to move in coordination, pulling the first height-adjusting rod 14 through the pitch angle-adjusting rod 13, so that the shovel 30 accurately deflects downward at the cutting angle when reaching the target depth. This delayed coordinated action triggered based on the target stroke percentage (0.8 times) effectively avoids mechanical wear caused by premature contact of the shovel tip with the ground.

[0035] Step Two: During the slag removal stroke, to overcome the arc-shaped motion trajectory caused by the rotation of the multi-bar mechanism, the control system uses the displacement of the height-adjusting hydraulic cylinder 17 as the primary control variable and the displacement of the pitch-angle-adjusting hydraulic cylinder 16 as the secondary compensation variable. The control system establishes a proportional linkage model for the extension and retraction of the two hydraulic cylinders in real time: LP = k(θ) × LH + b, where LP is the real-time extension and retraction length of the pitch-angle-adjusting hydraulic cylinder 16 and LH is the real-time extension and retraction length of the height-adjusting hydraulic cylinder 17.

[0036] k(θ) is the transmission ratio coefficient, and its value range is preset according to the length ratio of the first height adjustment rod 14 and the second height adjustment rod 15 to compensate for the vertical displacement deviation of the slag shovel 30 during the horizontal displacement process.

[0037] In this model, LP = k(θ) × LH + b, k(θ) = k0 + α × sin(θ), which essentially forces a linear approximation of the non-circular kinematics of a multi-bar mechanism. However, during the motion of the mechanism:

[0038] Within the small pitch angle range (close to horizontal, e.g., within ±10° of the horizontal line): the transmission ratio changes smoothly, and the error of the fixed k0 value is small; however, within the large pitch angle range (the shovel tilts downwards or upwards at a large angle): because the second height adjusting rod 15 makes circular motion around the hinge point, the ratio of its vertical displacement to its horizontal displacement ΔX / ΔZ changes non-linearly with the angle θ. If the fixed k0 value is still used at this time, it will lead to:

[0039] When the pitch angle is too large: the compensation is insufficient, the actual height of the shovel tip is higher than the theoretical value, resulting in "shovel drift" (the shovel tip leaves the ground and cannot effectively dig material).

[0040] If the pitch angle is too small (negative angle): the compensation is excessive, the actual height of the shovel tip is lower than the theoretical value, resulting in "grounding" (the shovel tip hitting the ground and damaging the equipment).

[0041] Through fitting calculations, this invention found that k0 satisfies a sine / cosine relationship in the large pitch angle range. Specifically, as a further improvement, in one embodiment, when θ is greater than or equal to 10° (10° upward from the horizontal line) or less than or equal to -10° (10° downward from the horizontal line), k(θ) is defined to dynamically change with the angle as follows: k(θ) = k0 + α × sin(θ), where k0 is a fixed value within ±10° of the horizontal line, and α is the transmission ratio correction coefficient. It can be understood that through the above correction, due to the functional characteristics of sin(θ), it can be made to precisely match the nonlinear change law of the vertical displacement component with the angle in the four-bar linkage. That is, at large pitch angles (sin(θ) increases), the transmission ratio coefficient k(θ) is automatically increased, which means that the pitch angle adjusting hydraulic cylinder 16 is required to perform a greater degree of compensation action to offset the additional vertical displacement component caused by the large-angle rotation of the second height adjusting rod 15. To ensure that the shovel tip maintains a parallelism error with the ground within ±2% (or even optimized to ±0.5%) across a wide working range greater than 10° or less than -10°, completely eliminating systematic trajectory deviations caused by angle changes. In one embodiment, when 10°>θ>-10°, α=0; when 20°>θ≥10°, or -10°≥θ>-20°, α=0.12k0; when 35°>θ≥20°, or -20°≥θ>-35°, α=0.20k0; with the horizontal direction of the rotating platform as the X-axis, the direction of the shovel as positive, and the direction perpendicular to the horizontal plane upward as the Y-axis; where θ is the instantaneous tilt angle of the second height adjustment rod relative to the X-axis.

[0042] b is the compensation constant under the initial operating state. The control system corrects the value of b in real time according to the initial height of the shovel 30 to ensure that the parallelism error between the shovel tip movement trajectory and the ground is controlled within ±2%.

[0043] In actual operation, the control system monitors the displacement change ΔLH of the height adjustment hydraulic cylinder 17 at a fixed frequency and calculates the target displacement LP=k(θ)×(LH+ΔLH)+b of the pitch angle adjustment hydraulic cylinder 16 in real time. Subsequently, the oil supply of the pitch angle adjustment hydraulic cylinder 16 is adjusted through an existing closed-loop PID algorithm to achieve synchronous linkage between the height adjustment hydraulic cylinder 17 and the pitch angle adjustment hydraulic cylinder 16. Utilizing the geometric constraint relationship between the first height adjustment rod 14 and the second height adjustment rod 15, the height fluctuation of the shovel 30 during the backward movement is dynamically offset, allowing the shovel tip to move smoothly along a predetermined horizontal straight line or preset curved trajectory.

[0044] To accurately derive the transmission ratio coefficient k(θ), a coordinate system needs to be established on the rotating platform 11.

[0045] Coordinate axis settings: The horizontal plane of the rotating platform 11 is the X-axis (positive in the direction of the slag shovel), and the Y-axis is perpendicular to the horizontal plane and pointing upwards.

[0046] Furthermore, define:

[0047] Hinge point A (reference point): The hinge point between the height adjustment hydraulic cylinder 17 and the rotating platform 11, with coordinates (0,0).

[0048] Hinge point B (first height point): The hinge point between the second height adjustment rod 15 and the rotating platform 11, with coordinates set as (XB, YB).

[0049] Hinge point C (pitch cylinder base point): The hinge point between the pitch angle adjusting hydraulic cylinder 16 and the rotating platform 11, with coordinates set as (XC, YC).

[0050] Step 3: During the material removal process, the control system monitors the hydraulic system pressure to determine the load condition. The loading threshold PL is set as follows: PL = Pm + ΔP. Where Pm is the hydraulic chamber pressure when the slag scraper 30 is unloaded, and ΔP is the pressure increment preset based on the density of the waste slag to be processed. When the pressure value collected by the control system for 0.5 consecutive seconds is greater than PL, the lifting action is automatically triggered, or the lifting action is also triggered when the working stroke is detected to be complete.

[0051] Upon triggering, the control system drives the height-adjusting hydraulic cylinder 17 to extend forward, causing the second height-adjusting rod 15 to rotate upward, thereby raising the entire slag-removing shovel 30. Simultaneously, the pitch-angle-adjusting hydraulic cylinder 16 retracts at a faster response speed than the height adjustment. Specifically, the retraction speed of the pitch-angle-adjusting hydraulic cylinder 16 is faster than that of the height-adjusting hydraulic cylinder 17, causing the connecting plate 12 to rotate the slag-removing shovel 30 upward to an elevation angle greater than 45° relative to the ground. At this time, the slag-removing shovel 30 rotates upward around its connection point with the first height-adjusting rod 14, forming a closed bearing posture to prevent waste slag from falling off.

[0052] In addition, the control system offers manual and automatic switching modes. In automatic mode, the control system reads the operation sequence table pre-stored in the PLC memory and automatically cycles through the above-mentioned cutting, unloading, and lifting stages until it receives the operation completion instruction, which greatly reduces the labor intensity of operators.

[0053] Working Principle: After the equipment starts, the PLC control system enters the cutting stage according to the set parameters. The height adjustment hydraulic cylinder 17 lowers first, and when it approaches the target depth (80% stroke), the pitch angle adjustment hydraulic cylinder 16 intervenes, allowing the slag scraper 30 to cut into the slag pile at the optimal angle. After entering the material scraping stage, the control system uses a pre-established proportional linkage model (LP=k(θ)×LH+b) and a PID closed-loop algorithm to automatically coordinate the extension and retraction speeds of the two hydraulic cylinders. This compensates for the vertical height difference caused by the circular motion of the multi-bar mechanism, enabling the slag scraper 30 to make high-precision horizontal linear motion at the bottom of the pit, avoiding uneven force or jamming. When the slag scraper 30 is filled with waste slag at the bottom of the pit (i.e., the hydraulic chamber pressure is greater than the load threshold PL for 0.5 seconds continuously), the system automatically determines to enter the lifting stage. At this time, the height hydraulic cylinder quickly raises, while the pitch angle hydraulic cylinder retracts at an even faster speed, causing the slag scraper 30 to "raise" more than 45° instantly, like a spoon, steadily scooping up the waste slag. The entire process is enhanced by over-limit forced braking protection from pressure sensors, achieving efficient, stable, and highly automated slag removal operations.

[0054] Example 1

[0055] Measured:

[0056] The effective distance between the second height adjustment rod 15 and the hinge point B is 1200mm;

[0057] The effective distance between the first height adjustment rod 14 and the pitch angle adjustment rod 13 is 1173mm;

[0058] The effective distance between the pitch angle adjustment rod 13 and the hinge point B is 670mm;

[0059] The effective distance between the pitch angle adjustment rod 13 and the hinge point C is 620mm;

[0060] Hinge point A: is set as the origin (0,0) mm.

[0061] Hinge point B: that is, the hinge point between the second height adjustment rod 15 and the rotating platform 11, with coordinates set as (-15, 375) mm.

[0062] Hinge point C: The hinge point between the pitch angle adjusting hydraulic cylinder 16 and the rotating platform 11, with coordinates set to (-850, 375) mm.

[0063] Step 1 (Initiation Phase):

[0064] The control system first obtains the set target cutting depth H0 = 270mm. The control system performs geometric calculations using the aforementioned coordinate system and rod parameters. Specifically, the effective distance between the second height adjusting rod 15 and hinge point B, the length from hinge point A to hinge point B, and the real-time total length of the height adjusting hydraulic cylinder 17 can be defined as a dynamic triangle; the effective distance between the second height adjusting rod 15 and hinge point B, the effective distance between the first height adjusting rod 14 and pitch angle adjusting rod 13, the effective distance between the pitch angle adjusting rod 13 and hinge point B, and the connecting plate 12 can be defined as a dynamic quadrilateral.

[0065] The effective distance between the second height adjustment rod 15 and the hinge point A is calculated to be 770mm, which means the required total length LH0 of the height adjustment hydraulic cylinder 17 is 770mm.

[0066] The control system first obtains the set target entry angle as 15°;

[0067] Similarly: the length from hinge point B to hinge point C, the effective distance between the pitch angle adjustment rod 13 and hinge point B, and the real-time total length of the pitch angle adjustment hydraulic cylinder 16;

[0068] The total length required for the pitch angle adjusting hydraulic cylinder 16 is 670mm.

[0069] When the height adjustment hydraulic cylinder moves to 0.8×LH0 (i.e. 616mm), it triggers the synchronous movement of the pitch angle adjustment hydraulic cylinder.

[0070] Step Two, Material Removal Stage:

[0071] Define k0=1, b=50; similar to step one, according to geometry, solve for θ=25°. According to the preset rule, when 35°>θ≥20°, α=0.20k0. The proportional linkage model of the extension and retraction of the two sets of hydraulic cylinders is LP=k(θ)×LH+b, k(θ)=k0+α×sin(θ), where θ is the instantaneous tilt angle of the second height adjustment rod relative to the X-axis; after correction:

[0072] k(25°) = k0 + 0.20k0 × sin(25°), that is, k(25°) 1.08; that is, the real-time total length LP of the pitch angle adjusting hydraulic cylinder 16 is 1.08×LH(770)+50=881.6mm.

[0073] Step 3, Improvement Phase:

[0074] The control system automatically determines whether to initiate a lifting action by monitoring the hydraulic system pressure. The loading threshold PL is set as follows: PL = Pm + ΔP. Here, Pm is the hydraulic chamber pressure when the slag shovel 30 is unloaded, and ΔP is a preset pressure increment based on the density of the waste slag to be processed. The lifting action is automatically triggered when the pressure value collected by the control system is greater than PL for 0.5 consecutive seconds, or when the lifting operation is detected to have ended.

[0075] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0076] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An automatic muck-loading control method for a muck-loading truck, the muck-loading truck comprising: Slag shovel; Connecting plate; Rotating platform; The pitch angle adjustment assembly is used to adjust the angle of the shovel relative to the ground; it includes a pitch angle adjustment rod, a first height adjustment rod, and a pitch angle adjustment hydraulic cylinder. A height adjustment assembly for adjusting the height of the shovel above the ground; including a second height adjustment rod and a height adjustment hydraulic cylinder; Control system; The control method is characterized by: Step 1: The control system drives the height adjustment component and the pitch angle adjustment component to jointly control the tip of the shovel to reach the predetermined depth and angle according to the target working depth. Step two: During the slag removal stroke, the control system uses the displacement of the height-adjusting hydraulic cylinder as the primary control variable and the displacement of the pitch-angle-adjusting hydraulic cylinder as the secondary compensation variable. A proportional linkage model for the extension and retraction of the two sets of hydraulic cylinders is established in real time: LP = k(θ) × LH + b, where k(θ) = k0 + α × sin(θ). Here, LP is the real-time total length of the pitch-angle-adjusting hydraulic cylinder, LH is the real-time total length of the height-adjusting hydraulic cylinder, k(θ) is the transmission ratio coefficient, and b is the compensation constant in the initial operating state. k0 is a fixed value within ±10° of the horizontal line, and α is the transmission ratio correction coefficient. When 10° > θ... When θ > -10°, α = 0; when 20° > θ ≥ 10°, or -10° ≥ θ > -20°, α = 0.12k0; when 35° > θ ≥ 20°, or -20° ≥ θ > -35°, α = 0.20k0; the horizontal direction of the rotating platform is taken as the X-axis, the direction of the slag shovel is positive, and the direction perpendicular to the horizontal plane and upward is taken as the Y-axis; where θ is the instantaneous tilt angle of the second height adjustment rod relative to the X-axis; by utilizing the geometric constraint relationship between the first height adjustment rod and the second height adjustment rod, the height fluctuation of the slag shovel during the backward movement is dynamically offset, so that the tip of the slag shovel moves smoothly along a predetermined horizontal straight line or a preset curved trajectory; Step 3: When the operation is detected to be completed or the load reaches the preset threshold, the control system drives the height adjustment hydraulic cylinder to extend forward, causing the second height adjustment rod to rotate upward to lift the slag shovel as a whole; at the same time, the control system controls the pitch angle adjustment hydraulic cylinder to retract at a response speed higher than that of the height adjustment, so that the slag shovel flips upward around its connection point with the first height adjustment rod, forming a closed bearing posture to prevent waste slag from falling off.

2. The automatic muck-loading control method for a muck-loading truck according to claim 1, characterized in that: In step two, the control system establishes the proportional linkage model based on a preset coordinate system; wherein, the origin (0,0) is taken as the hinge point A between the height adjustment hydraulic cylinder and the rotating platform in the height adjustment assembly; where: The coordinates of hinge point B (XB, YB): that is, the coordinates of the hinge point between the second height adjustment rod and the rotating platform; The coordinates (XC, YC) of hinge point C: that is, the coordinates of the hinge point between the pitch angle adjusting hydraulic cylinder and the rotating platform.

3. The automatic muck-loading control method for a muck-loading truck according to claim 2, characterized in that: The control system acquires the instantaneous tilt angle θ of the second height adjustment rod relative to the X-axis in real time.

4. The automatic muck-loading control method for a muck-loading truck according to claim 1, characterized in that: In step one, the control system first obtains the target cutting depth H0, calculates the required total length LH0 of the height adjustment hydraulic cylinder, and then extends or retracts according to the current length of the height adjustment hydraulic cylinder; when the height adjustment hydraulic cylinder moves to 0.8×LH0, the pitch angle adjustment hydraulic cylinder is triggered to move synchronously, so that the shovel accurately deflects downward at the cutting angle when it reaches the target depth.

5. The automatic muck-loading control method for a muck-loading truck according to claim 1, characterized in that: In step two, the control system corrects the value of b in real time based on the initial height of the shovel to ensure that the parallelism error between the shovel tip's movement trajectory and the ground is controlled within ±2%.

6. The automatic muck-loading control method for a muck-loading truck according to claim 1, characterized in that: In step two, the control system monitors the displacement change ΔLH of the height adjustment hydraulic cylinder at a fixed frequency and calculates the target displacement LP=k(θ)×(LH+ΔLH)+b of the pitch angle adjustment hydraulic cylinder in real time, so as to realize the synchronous linkage between the height adjustment hydraulic cylinder and the pitch angle adjustment hydraulic cylinder.

7. The automatic muck-loading control method for a muck-loading truck according to claim 1, characterized in that: In step three, the loading threshold PL is set as follows: PL = Pm + ΔP, where Pm is the hydraulic chamber pressure when the slag shovel is unloaded, and ΔP is the pressure increment preset according to the density of the waste slag to be processed; when the pressure value collected by the control system for 0.5 seconds is greater than PL, the lifting action is automatically triggered.

8. The automatic muck-loading control method for a muck-loading truck according to claim 7, characterized in that: During the lifting process in step three, the retraction speed of the pitch angle adjusting hydraulic cylinder is faster than that of the height adjusting hydraulic cylinder, causing the connecting plate to drive the slag scraper to flip upward to an elevation angle greater than 45° relative to the ground.

9. The automatic muck-loading control method for a muck-loading truck according to claim 1, characterized in that: The control system provides manual and automatic switching modes. In automatic mode, the control system reads the operation sequence table pre-stored in the PLC memory and automatically cycles through the cutting, unloading and lifting stages until it receives the operation completion instruction.

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