A calculation method for the lifting weight of a crane moment limiter

Abstract

The present invention discloses a method for calculating the lifting weight of a crane moment limiter, which includes: controlling the main boom to move from the minimum lifting amplitude to the maximum lifting amplitude and then return from the maximum lifting amplitude to the minimum lifting amplitude when the crane is in the states of empty hook, 33% rated load, and 66% rated load respectively, and recording the tension data and angle data; when the crane is in the 100% rated load state, controlling the main boom to perform lifting at the minimum lifting amplitude, and recording the tension data and angle data; generating four straight lines corresponding to different rated load states in a two-dimensional coordinate diagram based on the recorded tension data and angle data, obtaining the tension data and angle data in the actual site, generating measured points in the two-dimensional coordinate diagram to form a fifth straight line, and obtaining the actual lifting weight corresponding to the current main boom through equal-proportion or variable-proportion interpolation operation based on the slopes of other adjacent straight lines. Thus, the method has a simple model, fast calculation speed, low hardware requirements, and eliminates various calculations.

Description

Technical Field

[0001] The present invention relates to the technical field of construction machinery, and particularly to a method for calculating the load of a crane moment limiter. Background Art

[0002] The crane moment limiter obtains real-time working condition parameter signals from position sensors (measuring signals such as length and angle) and force sensors (measuring signals such as tension and pressure). The accuracy calibration method adopted is to measure the sensor signals of the crane under different loads in various working conditions, obtain the parameter conversion operation formula through a specific algorithm, and then write it into a single-chip microcomputer for processing and operation to obtain the actual load and amplitude and compare them with the maximum moment for judgment. A control signal is output in a dangerous state to prevent the crane from moving towards a dangerous state, thereby playing a safety protection role.

[0003] However, when the single-chip microcomputer performs processing and operation, the key to its core algorithm is the accurate calculation of the actual load. Most of the algorithm models in the prior art are calculated based on the moment balance theory. In this method, it is difficult for the moment limiter system using the single-chip microcomputer as the core controller to run large-scale simulation programs such as finite element analysis, and it is difficult to run large and complex algorithm models. It is necessary to spend a large amount of manpower, material resources and time on measuring the working condition parameters of the crane, and it is easy to produce errors due to accidental factors or human errors in the measurement process. Moreover, it is difficult to measure and collect the working condition parameter data during the movement of the boom, resulting in insufficient accuracy of the load moment limiter and false judgment. Moreover, the algorithm based solely on the moment balance theory obviously cannot meet the ±5% error requirement specified in the general technical conditions of the crane moment limiter. Summary of the Invention

[0004] To solve some or all of the technical problems existing in the above prior art, the present invention provides a method for calculating the load of a crane moment limiter.

[0005] The technical solution of the present invention is as follows:

[0006] A method for calculating the load of a crane moment limiter, the method is used for a crane that calculates the load through a moment limiter, and the method includes:

[0007] S1: When the crane is in the empty hook state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tension data and the corresponding angle data during the entire lifting process;

[0008] S2: When the crane is in the 33% rated load state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tension data and the corresponding angle data during the entire lifting process;

[0009] S3: When the crane is in the 66% rated load state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tensile force data and the corresponding angle data during the entire lifting process;

[0010] S4: When the crane is in the 100% rated load state, control the main boom of the crane to perform lifting at the minimum lifting amplitude, and record the tensile force data and the corresponding angle data during the lifting process;

[0011] S5: Establish a two-dimensional coordinate graph with the tensile force and the angle as the horizontal and vertical coordinates respectively. Based on the above-recorded tensile force data and the corresponding angle data, generate graphs corresponding to different rated load states in the two-dimensional coordinate graph. The graph includes a first straight line corresponding to the empty hook state, a second straight line corresponding to the 33% rated load state, a third straight line corresponding to the 66% rated load state, and a point corresponding to the 100% rated load state;

[0012] S6: In the two-dimensional coordinate graph, the extension lines of the first straight line, the second straight line and the third straight line intersect at a fixed point at the same time. Connect the point corresponding to the 100% rated load state with this fixed point to form a fourth straight line. This fourth straight line is used to represent the corresponding relationship between the tensile force data and the angle data in the 100% rated load state;

[0013] S7: Obtain the current tensile force data and angle data of the main boom in the actual field, generate a measured point corresponding to this tensile force data and angle data in the two-dimensional coordinate graph, connect this measured point with the fixed point to form a fifth straight line corresponding to the current main boom, obtain the slope of the fifth straight line, and based on the slopes of other adjacent straight lines, through equal-ratio or variable-ratio interpolation operations, obtain the actual lifting weight corresponding to the current main boom.

[0014] Optionally, S7 includes: partitioning in the two-dimensional coordinate graph based on the first straight line, the second straight line, the third straight line and the fourth straight line. Among them, the area between the first straight line and the second straight line is area A, the area between the second straight line and the third straight line is area B, the area between the third straight line and the fourth straight line is area C, and the area above the fourth straight line is area D. Among them,

[0015] When the fifth straight line is located in area A, the slope A5 of the fifth straight line is interpolated and calculated by means of the slopes of the first straight line and the second straight line, and the calculated actual lifting weight is between the empty hook weight and the 33% rated load weight;

[0016] When the fifth straight line is located in area B, the slope A5 of the fifth straight line is interpolated and calculated by means of the slopes of the second straight line and the third straight line, and the calculated actual lifting weight is between the 33% rated load weight and the 66% rated load weight;

[0017] When the fifth straight line is located in area C, the slope A5 of the fifth straight line is interpolated using the slopes of the third and fourth straight lines, and the actual load lifted calculated is between 66% and 100% of the rated load capacity.

[0018] When the fifth straight line is located in area D, the slope A5 of the fifth straight line is interpolated using the slopes of the third and fourth straight lines.

[0019] Optionally, S7 further includes: after changing the type of the hook, when the fifth straight line is below area A, the slope A5 of the fifth straight line is interpolated using the slopes of the first and second straight lines.

[0020] Optionally, the recorded tension data described above can be the tension value collected by a tension sensor or the pressure value of the main luffing cylinder.

[0021] Optionally, when the hoisting angle of the main boom is 90°, the tension is 0, and the coordinates of the fixed point where the extension lines of the first, second, and third straight lines intersect are (0, 90).

[0022] The main advantages of the technical solution of the present invention are as follows:

[0023] The load calculation method model of the crane moment limiter of the present invention is simple, has a fast calculation speed, has low requirements for hardware, has a wide application range, and omits the calculation of various component weights, a large number of hinge point positions, center of gravity positions, force arms, moments, block ratios, pulley block efficiencies, anti-backward tipping pressures, etc. in the moment balance formula calculation model, and can be applied to truss boom cranes, telescopic boom cranes, etc., providing a new idea for the algorithm model of the crane moment limiter. Description of the Drawings

[0024] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of the present invention, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 is a two-dimensional curve graph established based on the actually collected tension-angle data in one embodiment according to the present invention;

[0026] Figure 2 is for Figure 1 the data in to generate a two-dimensional coordinate graph, wherein different load lifting zones are divided based on different straight lines. Detailed Embodiments

[0027] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0028] The technical solutions provided by the embodiments of the present invention will be described in detail below in conjunction with the drawings.

[0029] As Figure 1 and Figure 2 shown, in an embodiment according to the present invention, a method for calculating the load of a crane moment limiter is provided. This method is used for a crane that calculates the load through a moment limiter, and can be used for the load calculation of moment limiters such as crawler cranes and truck cranes. It can be understood that the crane includes a main boom, a hoist, and a spreader; the pulling rope wound on the hoist bypasses the pulley block at the head of the main boom and is connected to the spreader. The main boom can move from the minimum lifting amplitude to the maximum lifting amplitude. During the movement of the main boom, the angle sensor can obtain the real-time angle data of the main boom, and at the same time, the tension sensor can collect the real-time tension data of the pull plate, and the hydraulic sensor can collect the real-time pressure data of the main luffing cylinder.

[0030] In this embodiment, the method includes:

[0031] S1: When the crane is in the empty hook state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tension data and the corresponding angle data during the entire lifting process;

[0032] S2: When the crane is in the 33% rated load state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tension data and the corresponding angle data during the entire lifting process;

[0033] S3: When the crane is in the 66% rated load state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tension data and the corresponding angle data during the entire lifting process;

[0034] S4: When the crane is in the 100% rated load state, control the main boom of the crane to lift at the minimum lifting amplitude, and record the tension data and the corresponding angle data during the lifting process;

[0035] S5: Establish a two-dimensional coordinate graph with the pulling force F and the angle A as the horizontal and vertical coordinates respectively. Based on the above-recorded pulling force data and the corresponding angle data, generate graphs corresponding to different load states in the two-dimensional coordinate graph. The graph includes a first straight line corresponding to the empty hook state, a second straight line corresponding to the 33% load state, a third straight line corresponding to the 66% load state, and a point corresponding to the 100% load state.

[0036] S6: In the two-dimensional coordinate graph, the extension lines of the first straight line, the second straight line, and the third straight line intersect at a fixed point simultaneously. Connect the point corresponding to the 100% load state with this fixed point to form a fourth straight line. This fourth straight line is used to represent the corresponding relationship between the pulling force data and the angle data under the 100% load state.

[0037] S7: Obtain the current pulling force data and angle data of the main boom in the actual field, generate a measured point corresponding to this pulling force data and angle data in the two-dimensional coordinate graph, connect this measured point with the fixed point to form a fifth straight line corresponding to the current main boom, obtain the slope of the fifth straight line, and based on the slopes of other adjacent straight lines, through equal-proportion or variable-proportion interpolation operations, obtain the actual lifting weight corresponding to the current main boom.

[0038] Exemplarily, as Figure 1 shown, the first straight line corresponding to the empty hook state, the second straight line corresponding to the 33% load state, the third straight line corresponding to the 66% load state, and a point corresponding to the 100% load state can be plotted in the two-dimensional pulling force-angle coordinate graph.

[0039] Theoretically, the intersection coordinates of the 3 straight lines should be (0, 90). That is to say, when the lifting angle of the main boom is 90°, the corresponding pulling force data should be 0. However, due to problems such as different working conditions and boom designs, the actual situation is not necessarily this coordinate.

[0040] In this embodiment, when the lifting angle of the main boom is 90°, the pulling force is 0, then the coordinates of the fixed point where the extension lines of the first straight line, the second straight line, and the third straight line intersect are (0, 90).

[0041] Optionally, the above-recorded pulling force data can be the pulling force value collected by a pulling force sensor or the pressure value of the main luffing cylinder.

[0042] Furthermore, according to the 4 straight lines obtained in the two-dimensional coordinate graph, we can divide it to obtain 4 regions.

[0043] Specifically, in S7, it includes: partitioning in a two-dimensional coordinate graph based on the first straight line, the second straight line, the third straight line, and the fourth straight line. Among them, the area between the first straight line and the second straight line is area A, the area between the second straight line and the third straight line is area B, the area between the third straight line and the fourth straight line is area C, and the area above the fourth straight line is area D.

[0044] Among them, area A is the area where the load is from the empty hook to 33% of the rated load weight, area B is the area where the load is from 33% of the rated load weight to 66% of the rated load weight, area C is the area where the load is from 66% of the rated load weight to 100% of the rated load weight, and area D is the area where the load exceeds 100% of the rated load weight.

[0045] During the process of calculating the actual load

[0046] When the fifth straight line is in area A, the slope A5 of the fifth straight line is interpolated and calculated by means of the slopes of the first straight line and the second straight line, and the calculated actual load is between the empty hook and 33% of the rated load weight;

[0047] When the fifth straight line is in area B, the slope A5 of the fifth straight line is interpolated and calculated by means of the slopes of the second straight line and the third straight line, and the calculated actual load is between 33% of the rated load weight and 66% of the rated load weight;

[0048] When the fifth straight line is in area C, the slope A5 of the fifth straight line is interpolated and calculated by means of the slopes of the third straight line and the fourth straight line, and the calculated actual load is between 66% of the rated load weight and 100% of the rated load weight;

[0049] When the fifth straight line is in area D, the slope A5 of the fifth straight line is interpolated and calculated by means of the slopes of the third straight line and the fourth straight line.

[0050] In addition, after changing the type of the hook, when the fifth straight line is below area A, the slope A5 of the fifth straight line is interpolated and calculated by means of the slopes of the first straight line and the second straight line.

[0051] To further describe the solution in this embodiment, when the coordinates of the fixed point are (0, 90), the straight-line equations corresponding to the above four straight lines are respectively:

[0052] The first straight line (empty-hook weight straight-line equation): y = A1x + 90;

[0053] The second straight line (33% rated load weight straight-line equation): y = A2x + 90;

[0054] The third straight line (66% rated load weight straight-line equation): y = A3x + 90;

[0055] The fourth straight line (100% rated load weight straight-line equation): y = A4x + 90;

[0056] The above four linear equations all intersect at the fixed point (0, 90). The only difference among these four linear equations lies in their slopes. It can be understood that in actual calculations, in addition to the different slopes, the intercepts will also be slightly different. However, in this embodiment, interpolation operations are mainly performed on the slopes. Therefore, in actual calculations, it is only a matter of the amount of calculation and does not affect the overall calculation accuracy.

[0057] Exemplarily, assume that the coordinate point generated by the currently collected tension data and angle data of the main boom is in area A. For example, the coordinates of this point are (x1, y1). Then, after connecting this point to the fixed point (0, 90), the equation of the formed straight line is y = A5x + 90. Interpolation calculations are performed based on the slope A5 between A1 and A2 to calculate a certain value between the empty hook and 33% of the rated load weight of the current lifting weight, and the actual lifting weight is obtained.

[0058] Specifically, if the first straight line (the straight line equation of the empty hook weight (10t)) is: y = -0.15x + 90; the second straight line (the straight line equation of 33% of the rated load weight (30t)): y = -0.13x + 90. The currently collected tension data and angle data of the main boom are 200 and 62 respectively, and the generated coordinate point is (200, 62). After connecting this point to (0, 90), according to the two-point formula of the straight line equation, the straight line equation of the current weight is:

[0059] (y - 62) / (90 - 62) = (x - 200) / (0 - 200);

[0060] After simplification, the equation of the fifth straight line is obtained as: y = -0.14x + 90. Its slope -0.14 is exactly in the middle between -0.13 and -0.15. After proportional conversion, the actual weight is also exactly in the middle between 10t and 30t, and the actual lifting weight at this time is obtained as 20t.

[0061] Thus, the lifting weight calculation method of the crane moment limiter in this embodiment has the following advantages:

[0062] The lifting weight calculation method model of the crane moment limiter of the present invention is simple, has a fast calculation speed, has low requirements for hardware, has a wide application range, and omits various calculations such as the weights of various components, the positions of a large number of hinge points, the center of gravity position, the force arm, the moment, the pulley ratio, the pulley block efficiency, the anti-backward tipping pressure, etc. in the moment balance formula calculation model. It can be applied to truss boom cranes, telescopic boom cranes, etc., providing a new idea for the algorithm model of the crane moment limiter.

[0063] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. In addition, in this text, "front", "rear", "left", "right", "upper" and "lower" are all referenced with respect to the placement state shown in the drawings.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A load calculation method for a crane moment limiter, characterized in that, The method is used for a crane that calculates the lifted weight through a torque limiter, and the method includes: S1: When the crane is in the empty-hook state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tension data and the corresponding angle data during the entire lifting process; S2: When the crane is in the 33% rated load state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tension data and the corresponding angle data during the entire lifting process; S3: When the crane is in the 66% rated load state, control the main boom of the crane to move from the minimum lifting amplitude to the maximum lifting amplitude, and then return from the maximum lifting amplitude to the minimum lifting amplitude, and record the tension data and the corresponding angle data during the entire lifting process; S4: When the crane is in the 100% rated load state, control the main boom of the crane to lift at the minimum lifting amplitude, and record the tension data and the corresponding angle data during the lifting process; S5: Establish a two-dimensional coordinate graph with tension and angle as the horizontal and vertical coordinates respectively. Based on the tension data corresponding to the empty-hook state and the corresponding angle data recorded in S1, the tension data corresponding to the 33% rated load state and the corresponding angle data recorded in S2, the tension data corresponding to the 66% rated load state and the corresponding angle data recorded in S3, and the tension data corresponding to the 100% rated load state and the corresponding angle data recorded in S4, generate graphs corresponding to different rated load states in the two-dimensional coordinate graph. The graph includes a first straight line corresponding to the empty-hook state, a second straight line corresponding to the 33% rated load state, a third straight line corresponding to the 66% rated load state, and a point corresponding to the 100% rated load state; S6: In the two-dimensional coordinate graph, the extension lines of the first straight line, the second straight line, and the third straight line intersect at a fixed point at the same time. Connect the point corresponding to the 100% rated load state with this fixed point to form a fourth straight line. This fourth straight line is used to represent the corresponding relationship between the tension data and the angle data in the 100% rated load state; S7: Obtain the current tension data and angle data of the main boom in the actual field, generate a measured point corresponding to this tension data and angle data in the two-dimensional coordinate graph, connect this measured point with the fixed point to form a fifth straight line corresponding to the current main boom, obtain the slope of the fifth straight line, and based on the slopes of other adjacent straight lines, through equal-ratio or variable-ratio interpolation operations, obtain the actual lifted weight corresponding to the current main boom.

2. The load calculation method for a crane moment limiter according to claim 1, characterized in that, What is included in S7 is: Based on the first straight line, the second straight line, the third straight line, and the fourth straight line, partition the two-dimensional coordinate graph. Among them, the area between the first straight line and the second straight line is area A, the area between the second straight line and the third straight line is area B, the area between the third straight line and the fourth straight line is area C, and the area above the fourth straight line is area D. Among them, When the fifth straight line is located in area A, the slope A5 of the fifth straight line is interpolated and calculated by means of the slopes of the first straight line and the second straight line, and the calculated actual lifted weight is between the empty-hook weight and the 33% rated load weight; When the fifth straight line is located in area B, the slope A5 of the fifth straight line is interpolated by means of the slopes of the second and third straight lines, and the actual load lifted calculated is between 33% and 66% of the rated load; When the fifth straight line is located in area C, the slope A5 of the fifth straight line is interpolated by means of the slopes of the third and fourth straight lines, and the actual load lifted calculated is between 66% and 100% of the rated load; When the fifth straight line is located in area D, the slope A5 of the fifth straight line is interpolated by means of the slopes of the third and fourth straight lines.

3. The load calculation method for a crane moment limiter according to claim 2, characterized in that, What is further included in S7 is: after the hook type is changed, when the fifth straight line is below area A, the slope A5 of the fifth straight line is interpolated by means of the slopes of the first and second straight lines.

4. The load calculation method for a crane moment limiter according to claim 1, characterized in that, The tensile force data recorded in S1, the tensile force data recorded in S2, the tensile force data recorded in S3, and the tensile force data recorded in S4 mentioned above are the tensile force values collected by the tensile force sensor.

5. The load calculation method for a crane moment limiter according to claim 1, characterized in that, The tensile force data recorded in S1, the tensile force data recorded in S2, the tensile force data recorded in S3, and the tensile force data recorded in S4 mentioned above are the pressure values of the main luffing oil cylinder.

6. The load calculation method for a crane moment limiter according to claim 1, characterized in that, When the hoisting angle of the main boom is 90°, the tensile force is 0, and the coordinates of the fixed point where the extension lines of the first, second, and third straight lines intersect are (0, 90).

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