Direct grab automatic loading process

Abstract

The application discloses a direct grab automatic loading process, which comprises the following steps: (1) real-time data acquisition; (2) acquisition of a loading point array position; (3) control of a travelling crane to the loading and unloading point position; (4) grab discharging; and (5) automobile material pile model updating. The application carries out limited material space gridding on the oxide scale material pile in the automobile grab, designs a loading model control algorithm, and realizes automatic control loading of the travelling crane grab.

Description

Technical Field

[0001] This invention is a divisional application of the invention application "An automatic loading model control algorithm for a vortex well trolley" (2021107334997), which relates to an automatic loading process, particularly an automatic loading process for a direct grab bucket. Background Technology

[0002] Cyclone well cranes are used for storing and retrieving slag from the well. The former includes grabbing and storing the slag into a sump, while the latter includes grabbing and loading the slag from the sump onto trucks for transport. To improve production efficiency, the challenge of automated loading control must be addressed.

[0003] The main technical challenges of automated loading control lie in: ① vehicle positioning, ② material loading model control, and ③ safety control to prevent spillage and collisions. The material loading model, in particular, is a highly complex stockpile model. It typically relies on laser scanning-assisted image recognition and sophisticated computer modeling to analyze the materials inside the vehicle, determine the optimal loading position, and safely control the loading process. This process is complex, has a long development cycle, and is costly; therefore, there are currently no successful industrial application cases in China.

[0004] Existing automated loading functions conventionally employ the method of constructing an intermediate silo. Iron oxide sheets are grabbed into a fixed material silo, and loading is achieved through unloading from the bottom of the silo. This method requires the construction of an intermediate silo. Most importantly, the typical height of an iron oxide sheet cyclone hoist is 9 meters. The silo height + the height of the truck unloading at the bottom of the silo + the grab bucket height generally exceed 12 meters, making it impossible to apply the automated loading function of existing cyclone hoist scoops. This limitation restricts the application of automated loading control for iron oxide sheet stacks; existing direct grab bucket loading typically relies on manual operation to control the scoop bucket.

[0005] Therefore, there is an urgent need for a simple and practical automatic loading model control method for iron oxide scale stacking to realize automatic loading of direct grab buckets. Summary of the Invention

[0006] The technical objective of this invention is to address the shortcomings of the prior art by providing a direct grab bucket automatic loading process. This process uses an algorithm to control the loading model of iron oxide scale, thereby solving the technical problem of automatic control loading of the crane grab bucket.

[0007] The technical solution of this invention to solve its technical problem is: an automatic loading process for direct grab buckets, characterized by including the following steps:

[0008] (6) Real-time data acquisition: Real-time reading of the position of the crane and trolley, the height of the grab bucket, the weight of the grab bucket, and the data of the grab bucket;

[0009] (7) Obtain the loading point matrix position: Load the truck according to the loading sequence of the points. If the height of the matrix is ​​greater than or equal to (the height of the truck bed sideboard - the safe unloading height to prevent spillage), skip the point and find the next point until a matrix that meets the conditions is found.

[0010] (8) Control the crane to the loading and unloading point;

[0011] (9) Grab bucket discharge: After the crane reaches the truck loading point, the grab bucket begins to descend. When the weight of the grab bucket begins to decrease, it indicates that the grab bucket has touched the material. At this time, the height of the material at the stacking point can be accurately obtained by the height of the grab bucket. Then the grab bucket is raised to a certain height and then stops. The closing cable continues to raise and discharge begins until the grab bucket is fully open and the discharge ends.

[0012] (10) Update the vehicle material pile model: After the material is discharged, the grab bucket rises to the safe translation height. According to the loading model algorithm, the height of each point matrix inside the vehicle is corrected to complete the control of the material model inside the vehicle.

[0013] Furthermore, the model establishment in the above loading model algorithm is as follows: a row of loading dot matrix, the number of dots = (vehicle length - 2 × safe distance between grab bucket and vehicle) / grab bucket width; the number of dots is rounded down to the final number of dots, and the dot matrix width is recalculated based on the determined number of dots; for each dot matrix of the vehicle loading, the material height is recorded.

[0014] Furthermore, the calculations in the above loading model algorithm are as follows: the increase in height h at the diffusion point and the distance from the diffusion point to the closing axis follow a normal distribution curve: when unloading on the in-vehicle plane, within the range of diffusion radius r = grab opening width / 3, the unloaded material accounts for 80% of the total unloading volume of this grab bucket; when piling material on a slope, the normal distribution function of the increase in height at each unloading point is:

[0015]

[0016] The value of σ on the upslope is calculated using the formula: (1-λk)r=1.3σ, where: k is the slope = difference between the unloading height at the center point of the grab bucket and the original lattice height / distance between the two points, and λ is the slope coefficient, ranging from 0.3 to 0.7; the value of σ on the downslope is calculated using the formula: (1+λk)r=1.3σ, where k is the slope and λ is the slope coefficient, ranging from 1 to 3.

[0017] The height correction for the dot matrix on both sides of the grab's center point is as follows:

[0018] Compared with the prior art, the present invention has the following outstanding advantages:

[0019] 1. This invention automatically obtains the position of the truck bed by using laser ranging and line marking for parking;

[0020] 2. This invention performs a limited material space gridding of the iron oxide scale pile in the truck bed and designs a loading model control algorithm to realize automatic control loading of the truck grab bucket, including automatic selection of loading position, automatic unloading, automatic stop when the material is full, and automatic update of the material pile model after each unloading. The material height at each loading point in the truck bed is displayed on the screen, and the material status inside the truck is dynamically displayed.

[0021] 3. It achieves safety control to prevent spillage and collisions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the vehicle position detection of the present invention.

[0023] Figure 2 This is a planar material distribution diagram of the present invention.

[0024] Figure 3 Material distribution diagram of inclined stacking according to the present invention.

[0025] Figure 4 This is a display diagram of the loading screen of the present invention.

[0026] Figure 5 This is a process control diagram for the vehicle assembly process of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] This invention obtains the spatial location area of ​​the truck bed through vehicle position detection, establishes a truck material stack model, and designs a truck material stack model control algorithm to realize the automatic loading function of the truck.

[0029] 1. Car positioning

[0030] To achieve automated loading of trucks, it is necessary to obtain the three-dimensional space area of ​​the truck bed. However, the parking position of trucks is somewhat random, and different types of trucks result in different widths, lengths, and heights. If this information cannot be obtained, there will be safety issues such as the grab bucket hitting the truck, scratching the truck, and spilling materials when loading.

[0031] Its positioning detection map is as follows Figure 1As shown, to obtain precise vehicle positioning, the vehicle must be parked parallel to oncoming traffic (either large or small vehicle, depending on the site layout). This can be achieved through management measures. To facilitate parking, a lane marking is drawn on the left side of the vehicle, requiring the driver to park with the left wheel close to this lane. This ensures parallel parking on the left and right sides of the vehicle and determines the positions of the left and right side panels of the truck bed. Once the rear position of the vehicle is determined, the entire truck bed space can be obtained based on the input truck bed length, width, floor height, and side panel height. Therefore, it is necessary to detect the rear position of the vehicle. This is achieved by installing a laser rangefinder at the rear of the vehicle to monitor the position of the rear panel, thus realizing the detection of the truck bed space position.

[0032] 2. Material loading model

[0033] (1) Three-dimensional model of the truck bed

[0034] Based on the fixed left-side position and rear monitoring position of the parked car, the absolute position of the lower right corner of the car can be determined. Then, based on the input length, width, floor height, and sideboard height of the car bed, a three-dimensional position model of the car bed can be obtained.

[0035] (2) Automobile loading model

[0036] Trucks are generally 2.2 to 2.5 meters wide, and the grab bucket opens to 1.8 to 2 meters wide. This width is just enough to accommodate the grab bucket's unloading width. Therefore, the truck model is divided into a row of loading dot matrix. The number of dot matrix is ​​determined according to the length of the truck. Sufficient safety distance must be left at both ends of each truck bucket to ensure that the grab bucket will not touch the front and rear side panels of the truck bucket during loading, thus achieving anti-collision safety control.

[0037] Number of dots = (Vehicle length - 2 × safe distance between grab bucket and vehicle) / grab bucket width

[0038] The number of dots obtained from the above formula needs to be rounded down. The rounded number is the final number of dots. Based on the final number of dots, the dot width is recalculated using the following formula:

[0039] Dot width = (vehicle length - 2 × safe distance between grabber and vehicle) / number of dots

[0040] For each point in the truck loading process, the material height is recorded, thus constructing a three-dimensional mathematical model of the material in the truck hopper.

[0041] (3) Collapse slope

[0042] After a truck loads the material, it may cause partial collapse of the stockpile. The slope angle α of the stockpile during collapse is the maximum slope of the stockpile. Based on the characteristics of iron oxide scale, α is selected to be between 30° and 70°, and the optimized scheme is 35° to 50°. The slope of the collapse is tag(α).

[0043] When loading materials onto a truck, the slope of adjacent lattice points (=height difference / lattice distance) ≤ tag(α).

[0044] (4) Car loading height

[0045] When discharging material, the grab bucket descends in the closed state until its weight is reduced to 0, indicating that the grab bucket has touched the material. At this point, the height of the grab bucket is the height of the material.

[0046] If the material is lower than the truck bed height during unloading, and the weight has not decreased, it indicates that the grab bucket has not touched the truck floor, meaning the truck is not parked at the loading point. The system will issue a fault alarm and stop unloading to ensure safety. If, during the initial unloading, the grab bucket height is greater than or equal to the truck bed side panel height, it indicates that the loading point has touched the truck bed side panel, suggesting a problem with truck positioning. The system will also issue a fault alarm and stop unloading. By judging the unloading height of the grab bucket, some special cases of inaccurate truck positioning or the truck not being in the parking position can be ruled out, effectively ensuring loading safety. This achieves safety control to prevent spillage and collisions in special circumstances.

[0047] (5) Loading point sequence

[0048] When loading a vehicle using a grab bucket, the loading is not done in the order of the dot matrix, but rather at alternate points. For example, if there are 5 loading dots for a vehicle, the loading dot matrix order is: 1→3→5→2→4→1…, and so on.

[0049] The advantage of loading in this order is that material is released between the two pile peaks, making it less likely for the grab bucket to tip over, and also providing better protection against spillage.

[0050] When the material height at a certain point is greater than or equal to (truck bed sideboard height - anti-spillage safety unloading height), that point is full and cannot be loaded anymore. Otherwise, the material will overflow the sideboard and spill outwards. In this case, the point will be skipped and the next point will be loaded until all points are full and the loading is finished.

[0051] (6) Calculation of loading model

[0052] When the grab bucket is loading material into the vehicle, the material distribution area spreads outwards to both sides along the grab bucket's opening direction, with the grab bucket's closing axis as the center line. The increase in height h of the diffusion point and the distance from the diffusion point to the closing axis follow a normal distribution curve: within the diffusion radius r = grab bucket opening width / 3, the unloaded material accounts for 80% of the total unloading volume of this grab bucket operation. At 2r, the unloading height is essentially zero. See the normal distribution diagram below. Figure 2 .

[0053] When stockpiling materials on a slope, the material is unloaded at an angle towards the downhill side. Therefore, in the distribution of the stockpiling area, the influence area on the uphill side is relatively small, so the distribution curve tends to converge towards the center. On the downhill side, the variance σ is larger, the influence area is larger, and the distribution curve expands outwards. See the distribution diagram. Figure 3 .

[0054] The normal distribution function of the increase in height at each unloading point is:

[0055]

[0056] h max σ is the height of the highest unloading point. x is the distance from the unloading point to the closed shaft. σ is the variance. e is the natural constant.

[0057] If unloading is done on the inside of the vehicle, and the material distribution accounts for 80% of the area within the unloading radius r = grab bucket width / 3, we can find from the table that x = 1.3σ, that is, r = 1.3σ, then σ = r / 1.3.

[0058] If unloading is done on a slope, the value of σ needs to be determined by analyzing whether it is an uphill or downhill slope. The calculation is as follows: Uphill slope: The value of σ is calculated according to the formula: (1-λk)r=1.3σ, where: k is the slope (difference between the unloading height of the grab bucket center point and the original lattice height / distance between the two points), λ is the slope coefficient, which ranges from 0.3 to 0.7 depending on the characteristics of iron oxide scale. λ is related to the viscosity of the material and the amount of sludge. The material and sludge content of each cyclone well do not vary much, but different cyclone wells will differ. Therefore, this variable is included. When the material viscosity is high or the sludge content is high, the value of λ is large, and vice versa. For example, when λ is 0.3 and k is 1, then... For unloading on a flat surface, σ = r / 1.3. With σ remaining constant, the unloading radius is reduced to 0.7r. For a downslope surface: the value of σ is calculated using the formula: (1 + λk)r = 1.3σ, where k is the slope, λ is the slope coefficient, and λ ranges from 1 to 3 depending on the characteristics of the iron oxide scale. For example, if λ is 1 and k is 1, then... When unloading in a plane, σ = r / 1.3. With σ remaining constant, the unloading radius increases to 2r.

[0059] The height correction for the dot matrix on both sides of the grab's center point is as follows:

[0060]

[0061] a) Original height after adjustment

[0062] If the slope between the unloading point at the center of the grab bucket and the dot matrix does not exceed the collapse slope, the original dot matrix height is used; otherwise, the unloading height at the center of the grab bucket is used as the reference point, and corrections are made according to the collapse slope. That is:

[0063] If the slope of the material slope satisfies the condition of not collapsing, then this value is taken as the original lattice height;

[0064] If the slope is greater than the collapse slope, the height is calculated by reverse calculation based on the collapse slope, using the unloading height at the center of the grab bucket as the reference point.

[0065] b) Increase the height h by unloading at the center point max

[0066] The central unloading point increases the height the most, and the calculation formula is:

[0067] h max = Grab bucket unloading weight / iron oxide scale density / material spreading area

[0068] The weight of the material discharged from the grab bucket is the weight difference before and after discharge. Since iron oxide is iron powder and iron filings, the density of iron oxide scale is taken as 2.75 t / m³. 3 .

[0069] Material spreading area = grab bucket depth × 4r 2 Calculate, where r = grab opening width / 3.

[0070] (7) Loading Stop Mode

[0071] There are three loading and stopping modes: full loading mode, weight mode, and loading count mode.

[0072] ① Full filling mode: that is, the filling height of all dot matrix points is ≥ (height of truck bed sideboard - safety unloading height to prevent spillage);

[0073] ② Weight mode: Stops when the loading weight exceeds the set weight value; it will also stop when the filling mode condition is met.

[0074] ③ Loading frequency mode: The loading frequency of the grab bucket will stop when the set value is exceeded. It will also stop when the full loading mode conditions are met.

[0075] (8) Display of material height for truck loading

[0076] Based on the loading model, the system automatically acquires the height of each point on the truck bed and compares it with the height of the sideboards. It then displays the percentage of material within the sideboard height of the hopper and shows the material height proportionally. This provides a clear view of the material distribution and surface height within the hopper. (See the image for details.) Figure 4 .

[0077] The specific implementation method is as follows:

[0078] After the crane performs a loading operation, the system automatically corrects the height of the dot matrix based on the position, height, and weight of the grab bucket to ensure the accuracy of the stacking dot matrix height.

[0079] like Figure 5 As shown, the process control is described in detail below:

[0080] (1) Real-time data acquisition

[0081] Real-time reading of the location of the crane and trolley, grab bucket height, grab bucket weight, and grab bucket height data.

[0082] (2) Obtain the loading point position

[0083] Loading proceeds sequentially by intermittent points. If the height of a point is greater than or equal to (height of truck bed sideboard - safe unloading height to prevent spillage), skip that point and search for the next point until a point that meets the conditions is found.

[0084] (3) Control the crane to the loading and unloading point.

[0085] (4) Grab bucket discharge

[0086] After the crane reaches the truck loading point, the grab bucket begins to descend. When the weight of the grab bucket begins to decrease, it indicates that the grab bucket has touched the material. At this time, the height of the material at the stacking point can be accurately obtained by measuring the height of the grab bucket. Then, the grab bucket is raised to a certain height and stops. The closing cable continues to raise the grab bucket and begins to discharge the material until the grab bucket is fully open and the discharge is completed.

[0087] (5) Update of automobile stockpile model

[0088] After the material is discharged, the grab bucket rises to a safe horizontal movement height. Based on the loading model algorithm, the height of each point matrix inside the vehicle is corrected to complete the control of the material model inside the vehicle.

[0089] It should be noted that any aspects not described in detail in this embodiment are techniques well-known in the art. Only certain exemplary embodiments have been briefly described above. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of this invention. Therefore, the drawings and descriptions are considered exemplary in nature and not restrictive.

[0090] The present invention has been described in detail with reference to specific embodiments thereof. For those skilled in the art, various obvious changes made to it without departing from the spirit and scope of the present invention are within the protection scope of the present invention.

Claims

1. An automated loading process using a direct grab bucket, characterized in that: Includes the following steps: (1) Real-time data acquisition: Real-time reading of the position of the crane and the grab bucket, the grab bucket height, the grab bucket weight, and the grab bucket height data; (2) Obtain the loading point position: Load the truck according to the loading order of the points. If the height of the point is greater than or equal to (the height of the truck bed sideboard - the safe unloading height to prevent spillage), skip the point and find the next point until a point that meets the conditions is found. (3) Control the crane to the loading and unloading point; (4) Grab bucket discharge: After the crane reaches the truck loading point, the grab bucket begins to descend. When the weight of the grab bucket begins to decrease, it means that the grab bucket has touched the material. At this time, the height of the material at the stacking point can be accurately obtained by the height of the grab bucket. Then the grab bucket is raised to a certain height and then stops. The closing cable continues to raise and discharge begins until the grab bucket is fully open and the discharge ends. (5) Update the truck stockpile model: After the material is discharged, the grab bucket rises to the safe translation height. According to the loading model algorithm, the height of each point matrix inside the truck is corrected to complete the control of the material model inside the truck. The calculations in the loading model algorithm state that the increase in height h at the diffusion point and the distance from the diffusion point to the closing axis follow a normal distribution curve: When unloading on a flat surface inside the vehicle, within the range of diffusion radius r = grab opening width / 3, the unloaded material accounts for 80% of the total unloading volume of the grab bucket; when piling material on a slope, the normal distribution function of the increase in height at each unloading point is: The value of σ on the upslope is calculated using the formula: (1-λk)r=1.3σ, where: k is the slope = difference between the unloading height at the center point of the grab bucket and the original lattice height / distance between the two points, and λ is the slope coefficient, ranging from 0.3 to 0.7; the value of σ on the downslope is calculated using the formula: (1+λk)r=1.3σ, where k is the slope and λ is the slope coefficient, ranging from 1 to 3. The corrected height of the dot matrix on both sides of the grab's center point is: Corrected dot matrix height = Original height after adjustment + .

2. The direct grab bucket automatic loading process according to claim 1, characterized in that: The model establishment in the loading model algorithm is: a row of loading dot matrix, the number of dots = (vehicle length - 2 × safe distance between grab bucket and vehicle) / grab bucket width; The final number of dots is determined by rounding down the number of dots. The dot width is then recalculated based on the determined number of dots. For each point on the truck loading system, the material height is recorded.

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