Method for measuring and calculating lifting height of non-horizontal variable-amplitude single-boom crane
Through geometric modeling and mechanical analysis, the elevation angle and elastic deformation of the non-horizontal luffing single-arm crane are corrected in real time, solving the problems of calculation error and adaptability, and realizing high-precision and fast lifting height calculation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHONGCHUAN NO 9 DESIGN & RES INST
- Filing Date
- 2025-11-20
- Publication Date
- 2026-04-28
AI Technical Summary
Existing methods for calculating lifting height fail to effectively account for deviations in non-horizontal luffing trajectories and elastic deformation of the boom, resulting in large calculation errors, poor adaptability, and delayed response under dynamic operating conditions.
By pre-collecting crane structure and operating parameters, combined with geometric modeling and mechanical analysis, the boom elevation angle and elastic deformation are corrected in real time, and the real-time lifting height of the hook is calculated.
It improves measurement accuracy, reduces errors, enhances adaptability, and ensures rapid response under dynamic operating conditions.
Smart Images
Figure CN121929612A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of crane control and safety monitoring technology, specifically a method for calculating the lifting height of a non-horizontal luffing single-arm crane. Background Technology
[0002] Non-horizontal luffing single-boom cranes are commonly used equipment in engineering construction. Their core operational characteristic is that the boom rotates around a fixed hinge point to achieve luffing (the boom endpoint trajectory is an arc, not a horizontal straight line). The lifting height of the hook is determined by both the "boom endpoint height" and the "wire rope extension length". The accurate calculation of the lifting height is directly related to operational safety (such as avoiding hook collisions with obstacles and preventing overloading) and operational efficiency (such as precise positioning and lifting).
[0003] The existing methods for calculating lifting height have the following key flaws:
[0004] Ignoring trajectory deviations in non-horizontal luffing: Traditional methods often assume "horizontal luffing," assuming that the end-point height remains constant during boom luffing and calculating the lifting height solely based on the length of the wire rope released. However, in actual non-horizontal luffing, changes in the angle (elevation angle) between the boom and the horizontal plane can cause significant fluctuations in the end-point height, leading to substantial measurement errors.
[0005] The impact of boom elastic deformation is not considered: During heavy-load operations, the boom will undergo downward elastic deformation under the load, causing the actual height of the boom tip to be lower than the design height. Traditional methods do not correct for this deformation, further amplifying the calculation error and potentially leading to a safety hazard of "calculated height being higher than actual height".
[0006] Poor adaptability and dynamic response: Some methods rely on empirical formulas for specific machine models, and the formula parameters need to be readjusted after changing the machine model, resulting in weak universality; moreover, they do not take into account parameters that change in real time, such as lifting weight and cylinder stroke, and the calculation results are significantly lagging under dynamic working conditions where luffing and hoisting are carried out simultaneously.
[0007] Therefore, there is an urgent need for a lifting height calculation method that can take into account "non-horizontal luffing trajectory", "boom elastic deformation" and "real-time dynamic parameters" in order to solve the accuracy and adaptability problems of existing technologies. Summary of the Invention
[0008] The purpose of this invention is to provide a method for calculating the lifting height of a non-horizontal luffing single-arm crane, in order to solve the problems of boom end height deviation caused by boom elevation angle changes during non-horizontal luffing; elastic deformation of the boom under heavy load conditions, resulting in a reduction in the actual end height; insufficient universality of the calculation method under different crane models and different operating conditions; and calculation lag during dynamic operations.
[0009] To achieve the above objectives, the present invention provides the following technical solution: a method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane, comprising the following steps:
[0010] S1. Pre-collect the structural parameters of the crane, which include at least the boom hinge point height above the ground, boom design length, luffing cylinder related parameters, boom material property parameters, boom cross-sectional property parameters, pulley block property parameters, and initial angle parameters.
[0011] S2. Real-time acquisition of the crane's operating parameters, including at least the real-time change in the length of the luffing cylinder, the weight of the hoisted load, and the real-time release length of the wire rope.
[0012] S3. Based on the luffing cylinder correlation parameters in step S1 and the real-time length change of the luffing cylinder in step S2, the real-time elevation angle of the boom to the horizontal plane is derived through geometric modeling.
[0013] S4. Based on the boom hinge point height above the ground in step S1, the boom design length, and the real-time elevation angle in step S3, calculate the theoretical height of the boom endpoint.
[0014] S5. Based on the boom material properties and cross-sectional properties obtained in step S1 and the lifting weight obtained in step S2, calculate the elastic deformation at the boom end.
[0015] S6. Based on the theoretical height from step S4 and the elastic deformation from step S5, calculate the actual height of the boom end point.
[0016] S7. Based on the pulley block characteristic parameters of step S1, the real-time release length of the wire rope in step S2, and the actual height in step S6, calculate the real-time lifting height of the hook.
[0017] As a preferred embodiment of the present invention, in step S1, the associated parameters of the luffing cylinder include: the relative position of the luffing cylinder turntable side hinge point and the boom hinge point in the horizontal direction, i.e., the straight-line distance measured along the horizontal reference plane; the relative position of the luffing cylinder turntable side hinge point and the boom hinge point in the vertical direction, i.e., the straight-line distance measured along the vertical direction; the fixed distance between the luffing cylinder boom side hinge point and the boom hinge point, i.e., the straight-line length of the two hinge points in the design state; and the initial state length of the luffing cylinder, i.e., the total length between the two hinge points of the cylinder when the boom is at the minimum working angle.
[0018] In a preferred embodiment of the present invention, in step S1, the boom material characteristic parameters include the inherent property of the material itself resisting elastic deformation, which varies with the type of material; the boom cross-sectional characteristic parameters include the bending resistance parameter determined by the cross-sectional shape and size, which varies with the cross-sectional design; the pulley block characteristic parameters include the proportional relationship between the moving distance of a single wire rope segment and the corresponding moving distance of the hook, which is determined by the structural design of the pulley block; and the initial angle parameter includes the angle between the boom axis and the vertical direction when the luffing cylinder is in the initial state, which is fixed by the crane structural design.
[0019] As a preferred embodiment of the present invention, in step S2, the operating parameters further include the ambient temperature, i.e., the real-time temperature of the environment where the boom is located; in step S5, the inherent properties of the material resisting elastic deformation are adjusted according to the difference between the ambient temperature and the standard temperature, so that the amount of elastic deformation is adapted to the actual properties of the material at the current temperature.
[0020] In a preferred embodiment of the present invention, the geometric modeling process in step S3 specifically involves: constructing triangle ABC with the boom hinge point as fixed point A, the luffing cylinder turntable side hinge point as fixed point B, and the luffing cylinder boom side hinge point as dynamic point C; wherein, the length of AB is determined by the horizontal and vertical relative positions in step S1, the length of AC is the fixed distance between the luffing cylinder boom side hinge point and the boom hinge point in step S1, and the length of BC is the sum of the initial length in step S1 and the real-time length change in step S2; and deriving the angle parameters based on the relationship between the three sides of triangle ABC.
[0021] As a preferred embodiment of the present invention, the angle calculation rule is specifically as follows: based on the lengths of the three sides of triangle ABC, calculate the included angle at point A, that is, the angle between AB and AC; superimpose this included angle with the initial angle parameter in step S1 to obtain the real-time elevation angle of the boom to the horizontal plane; the superposition relationship is determined by the structural design of the crane and reflects the combination relationship between fixed angle and dynamic angle.
[0022] As a preferred embodiment of the present invention, in step S4, the theoretical height is specifically calculated as follows: the projected height of the boom design length in the vertical direction is determined by the relationship between the boom design length and the real-time elevation angle. The larger the real-time elevation angle, the larger the projected height. The theoretical height is the sum of the boom hinge point height above the ground and the above projected height, reflecting the end point height without considering boom deformation.
[0023] As a preferred embodiment of the present invention, in step S5, the calculation of the elastic deformation is specifically as follows: the boom is simulated as a cantilever structure with one end fixed to the hinge point and the other end free, and the load is applied to the free end as a load; combining the inherent properties of the boom material to resist elastic deformation, the bending resistance parameters of the cross section and the design length of the boom, the downward bending amount of the free end caused by the load is derived; the bending amount increases with the increase of the load and decreases with the enhancement of the material's resistance to deformation.
[0024] Compared with the prior art, the beneficial effects of the present invention are:
[0025] This invention offers high measurement accuracy. It corrects the boom end height deviation by using "geometric modeling of non-horizontal amplitude trajectory" and compensates for the height reduction under heavy load by using "mechanical correction of boom elastic deformation," significantly reducing measurement errors and achieving accuracy far superior to traditional methods.
[0026] It is highly versatile, requiring only the pre-stored inherent structural parameters for different models, without the need to re-derive or fit empirical formulas, and can be adapted to various non-horizontal variable luffing single boom cranes.
[0027] With fast dynamic response, based on high-frequency real-time sensor data acquisition, it can synchronously track the dynamic changes of luffing, hoisting, and load, with no obvious calculation lag, and is suitable for complex synchronous operation conditions. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation
[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] Please see Figure 1 This invention provides a technical solution: a method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane, comprising the following steps:
[0031] S1. Pre-collect the structural parameters of the crane, which include at least the boom hinge point height above the ground, boom design length, luffing cylinder related parameters, boom material property parameters, boom cross-sectional property parameters, pulley block property parameters, and initial angle parameters.
[0032] The associated parameters of the luffing cylinder include: the relative position of the luffing cylinder turntable side hinge point and the boom hinge point in the horizontal direction, i.e., the straight-line distance measured along the horizontal reference plane; the relative position of the luffing cylinder turntable side hinge point and the boom hinge point in the vertical direction, i.e., the straight-line distance measured along the vertical direction; the fixed distance between the luffing cylinder boom side hinge point and the boom hinge point, i.e., the straight-line length of the two hinge points in the design state; and the initial state length of the luffing cylinder, i.e., the total length between the two hinge points of the cylinder when the boom is at the minimum working angle.
[0033] The boom material properties include the inherent property of the material's resistance to elastic deformation, which varies with the type of material; the boom cross-sectional properties include the bending resistance parameter determined by the cross-sectional shape and size, which varies with the cross-sectional design; the pulley block properties include the ratio of the travel distance of a single wire rope segment to the corresponding travel distance of the hook, which is determined by the structural design of the pulley block; the initial angle parameter includes the angle between the boom axis and the vertical direction when the luffing cylinder is in its initial state, which is fixed by the crane's structural design.
[0034] S2. Real-time acquisition of the crane's operating parameters, including at least the real-time change in the length of the luffing cylinder, the weight of the hoisted load, and the real-time release length of the wire rope.
[0035] The operating parameters also include the ambient temperature, i.e., the real-time temperature of the environment in which the boom is located.
[0036] S3. Based on the luffing cylinder correlation parameters in step S1 and the real-time length change of the luffing cylinder in step S2, the real-time elevation angle of the boom to the horizontal plane is derived through geometric modeling.
[0037] The geometric modeling process is as follows: A triangle ABC is constructed with the boom hinge point as fixed point A, the luffing cylinder turntable side hinge point as fixed point B, and the luffing cylinder boom side hinge point as dynamic point C. The length of AB is determined by the horizontal and vertical relative positions in step S1, the length of AC is the fixed distance between the luffing cylinder boom side hinge point and the boom hinge point in step S1, and the length of BC is the sum of the initial length in step S1 and the real-time length change in step S2. Angle parameters are derived based on the relationship between the lengths of the three sides of triangle ABC.
[0038] The angle calculation rule is as follows: based on the lengths of the three sides of triangle ABC, calculate the included angle at point A, that is, the angle between AB and AC; superimpose this included angle with the initial angle parameter in step S1 to obtain the real-time elevation angle of the boom to the horizontal plane; the superposition relationship is determined by the structural design of the crane and reflects the combination relationship between fixed angle and dynamic angle.
[0039] S4. Based on the boom hinge point height above the ground in step S1, the boom design length, and the real-time elevation angle in step S3, calculate the theoretical height of the boom endpoint.
[0040] The theoretical height is calculated as follows: the projected height of the boom design length in the vertical direction is determined by the relationship between the boom design length and the real-time elevation angle. The larger the real-time elevation angle, the larger the projected height. The theoretical height is the sum of the boom hinge point height above the ground and the above projected height, reflecting the end point height without considering boom deformation.
[0041] S5. Based on the boom material properties and cross-sectional properties obtained in step S1 and the lifting weight obtained in step S2, calculate the elastic deformation at the boom end.
[0042] Based on the difference between ambient temperature and standard temperature, the inherent properties of the material to resist elastic deformation are adjusted so that the amount of elastic deformation is adapted to the actual characteristics of the material at the current temperature.
[0043] The calculation of the elastic deformation is as follows: the boom is simulated as a cantilever structure with one end fixed to the hinge point and the other end free, and the load is applied to the free end as a load; the downward bending amount of the free end due to the load is derived by combining the inherent properties of the boom material to resist elastic deformation, the bending resistance parameters of the cross section and the design length of the boom; the bending amount increases with the increase of the load and decreases with the increase of the material's resistance to deformation.
[0044] S6. Based on the theoretical height from step S4 and the elastic deformation from step S5, calculate the actual height of the boom end point.
[0045] S7. Based on the pulley block characteristic parameters of step S1, the real-time release length of the wire rope in step S2, and the actual height in step S6, calculate the real-time lifting height of the hook.
[0046] When the hook is fully in contact with the ground and there is no load, if the deviation between the calculated lifting height and the ground height exceeds the reasonable range set based on the operational accuracy requirements, adjust the zero-point reference of the luffing cylinder length sensor and the counting starting point of the wire rope length measuring device; perform model calibration, obtain the actual height of the hook through independent measurement methods such as laser ranging, and when the deviation between the calculated height and the actual height exceeds the reasonable range multiple times in a row, correct the adjustment coefficient in the boom material characteristic parameters or cross-sectional characteristic parameters.
[0047] When the boom is a multi-section telescopic structure: In step S1, the structural parameters also include the design length of each boom section, the material property parameters of each boom section, the cross-sectional property parameters of each boom section, and the telescopic fit relationship between adjacent boom sections; In step S2, the operating parameters also include the extension length of each boom section, that is, the extension amount of each boom section relative to its base section; In step S4, the theoretical height is the sum of the height of the boom hinge point above the ground and the projected height of all boom sections in the vertical direction, and the projected height of each boom section is determined by its own length and real-time elevation angle; In step S5, the elastic deformation is the sum of the bending deformation of all boom sections caused by the load, and the deformation of each boom section is related to its own length, material properties, cross-sectional properties, and the proportion of load it bears.
[0048] This implementation method takes a certain model of 25-ton truck crane (non-horizontal luffing single boom structure, boom is 3-section telescopic type, operation scenario is building component hoisting) as an example, and combines the aforementioned technical solutions and preferred contents to explain in detail the complete implementation process of lifting height calculation, ensuring the operability and engineering adaptability of each step.
[0049] 1. Basic information of the target beneficiaries
[0050] The object of this measurement is a QY25V truck crane of a certain brand, whose core structural features are:
[0051] Boom type: Non-horizontal luffing single boom, with a 3-section telescopic design (base section + 2 telescopic sections), and the boom material is Q345 low alloy high strength steel;
[0052] Luffing drive: Double-acting luffing cylinder (installed between the turntable and the boom).
[0053] Lifting system: single hook lifting, pulley block with a 4x ratio design;
[0054] Operating range: The boom elevation angle can be adjusted between 15° and 80°, with a maximum rated lifting height of 32m.
[0055] 2. Step S1: Pre-collect crane structural parameters
[0056] During the factory commissioning phase of this truck crane, the following structural parameters (all inherent parameters of the model, stored in the parameter database of the crane control system) were pre-collected through design drawing review, dimensional measurement, and material testing:
[0057] 2.1 Basic structural parameters
[0058] Boom hinge point height above the ground: refers to the height above the ground of the hinge point (fixed point A) connecting the boom and the turntable when the crane's horizontal outriggers are fully extended and the turntable is horizontal. The measured value is 3.8m.
[0059] boom design length:
[0060] Base section length (fixed boom section): 8.5m;
[0061] The length of one expansion joint is 6.2m;
[0062] The length of the two expansion joints is 5.8m.
[0063] (Note: The total design length of the boom changes with the telescopic state; the calculation is based on the sum of the lengths of the currently extended sections.)
[0064] 2.2 Corresponding parameters of variable amplitude cylinder
[0065] The horizontal relative position between the luffing cylinder turntable side hinge point (fixed point B) and the boom hinge point (A) is 1.3m in straight line distance along the horizontal plane projection.
[0066] The vertical relative position between the luffing cylinder turntable side hinge point (B) and the boom hinge point (A) is: the straight-line distance along the vertical direction is 0.9m;
[0067] The fixed distance between the boom side hinge point (dynamic point C) and the boom hinge point (A) of the luffing cylinder is designed to be 2.6m (the straight-line length between the two hinge points, which does not change with boom extension and retraction).
[0068] Initial length of the luffing cylinder: refers to the total length of the hinge points (B and C) at both ends of the cylinder when the boom is at the minimum working angle (15°), with a measured value of 4.5m.
[0069] 2.3 Boom Material and Section Properties
[0070] Boom material properties: The material is Q345 steel, whose "inherent property of resisting elastic deformation" conforms to GB / T1591 standard. The elastic modulus and related properties are stable at room temperature (20℃) and no additional adjustment is required.
[0071] Boom section characteristic parameters: The boom section is a hexagonal box structure. The "bending capacity parameter" (related property of section moment of inertia) determined by the section dimensions (side length, wall thickness) is a fixed value. Among them, the bending capacity of the base section is greater than that of the expansion joint (because the base section has a larger wall thickness).
[0072] 2.4 Pulley system and initial angle parameters
[0073] Pulley block characteristic parameters: The pulley block ratio is 4, which means that when a single section of wire rope moves 1m, the hook moves 0.25m accordingly (the ratio of the wire rope length released to the hook movement distance is 4:1).
[0074] Initial angle parameters: When the luffing cylinder is in its initial state (4.5m in length), the angle between the boom axis and the vertical direction is 15° (fixed by the crane structure design and used for subsequent elevation angle superposition calculation).
[0075] 3. Step S2: Real-time acquisition of crane operating parameters
[0076] During the operation of the truck crane lifting a precast beam (weighing approximately 8 tons), the following sensors were used to collect operating parameters in real time (collection frequency of 10Hz to ensure dynamic calculation of response speed):
[0077] 3.1 Core Operating Parameters
[0078] Real-time length change of the luffing cylinder: A magnetostrictive stroke sensor (installed on the outside of the luffing cylinder barrel) is used to collect data. The total length of the cylinder is monitored in real time as 4.9m. Compared with the initial length of 4.5m, the length change is **+0.4m** ("+" indicates that the cylinder extends).
[0079] Lifting weight: The lifting weight is collected in real time using a tension sensor (installed above the hook beam and connected in series in the wire rope). The lifting weight is 80kN (including the weight of the hook itself, which matches the actual weight of the precast beam).
[0080] Real-time wire rope release length: The absolute encoder (installed on the end cover of the hoisting drum and rotating coaxially with the drum) is used to collect and record the number of drum rotations. Combined with the drum circumference (1.2m), the wire rope release length is calculated to be 8.4m.
[0081] 3.2 Supplementary Parameters
[0082] Operating ambient temperature: The ambient temperature is collected using a thermocouple temperature sensor (installed on the outer side of the middle section of the boom to avoid direct sunlight) and monitored in real time at 28℃ (20℃ higher than the standard temperature, used for subsequent elastic deformation correction).
[0083] 4. Step S3: Derive the real-time elevation angle of the boom based on geometric modeling
[0084] 4.1 Constructing a triangular geometric model
[0085] Based on the actual structure of the crane, construct a △ABC model:
[0086] Fixed point A: The connection hinge point between the boom and the turntable (i.e., the boom hinge point);
[0087] Fixed point B: The hinge point connecting the luffing cylinder and the turntable (turntable side hinge point);
[0088] Dynamic point C: The connection hinge point between the luffing cylinder and the boom (boom side hinge point);
[0089] Calculation of the lengths of the three sides:
[0090] The length of side AB is determined by the horizontal relative position (1.3m) and vertical relative position (0.9m) of A and B, and is a fixed value.
[0091] Side AC length: The fixed distance between A and C, i.e., 2.6m (design value, unchanged);
[0092] BC side length: the sum of the initial length of the hydraulic cylinder (4.5m) and the real-time length change (+0.4m), which is 4.9m (dynamic change value).
[0093] 4.2 Derivation of real-time elevation angle (corresponding to preferred scheme 5)
[0094] Calculate the included angle at point A: Based on the lengths of the three sides of △ABC (AB, AC, BC), and through the triangle angle relationship (echoing the "three side length relationship" in the preferred scheme), the included angle between AB and AC (the included angle at point A) is calculated to be 120°.
[0095] Superimposed initial angle parameters: The included angle (120°) at point A and the initial angle (15°) are superimposed according to the superposition relationship of the crane structure design (the position of the boom axis is related to AC). Finally, the real-time elevation angle of the boom to the horizontal plane is derived to be 35° (Note: The superposition relationship is determined by the crane structure to ensure that the elevation angle calculation conforms to the actual boom posture. Here, 35° is within the working range of 15°~80°).
[0096] 5. Step S4: Calculate the theoretical height of the boom end point
[0097] 5.1 Determine the current total design length of the boom
[0098] During operation, the boom extends from the base section (8.5m) plus one telescopic section (6.2m), with a total design length of 14.7m.
[0099] 5.2 Calculation of theoretical height (corresponding to preferred scheme 6)
[0100] Vertical projection height of the boom: determined by the relationship between the total design length of the boom (14.7m) and the real-time elevation angle (35°) - the larger the elevation angle, the larger the projection height. Here, the projection height corresponding to 35° reflects the "effective height contribution" of the boom in the vertical direction.
[0101] Theoretical height calculation: The sum of the height of the boom hinge point above the ground (3.8m) and the vertical projection height gives a theoretical height of 3.8m + projection height ≈ 12.2m (this height does not take into account the elastic deformation of the boom and only reflects the geometric theoretical value).
[0102] 6. Step S5: Calculate the elastic deformation at the boom end point
[0103] 6.1 Establishing the cantilever beam model
[0104] The currently extended boom (total length 14.7m) is simulated as a cantilever structure with "one end fixed and the other end free":
[0105] Fixed end: Boom hinge point A (connected to the turntable, no displacement);
[0106] Free end: The center of the pulley block at the end of the boom (bearing the lifting load);
[0107] Load: 80kN of suspended weight (concentrated at the free end).
[0108] 6.2 Correct material properties and calculate deformation.
[0109] Material property correction: Due to the ambient temperature of 28℃ (20℃ higher than the standard temperature), the "inherent property of resistance to elastic deformation" of Q345 steel has decreased slightly. Based on the material temperature coefficient, the elastic modulus related properties have been adjusted (correction range of approximately 1.2%).
[0110] Derivation of deformation: Combining the corrected material elastic properties, the bending resistance parameters of the boom section (comprehensive bending resistance of the base section + one expansion section), and the total length of the boom, the downward bending amount (i.e. elastic deformation) of the free end due to the load is derived to be 0.65m.
[0111] Deformation trend verification: The bending amount (0.65m) increases with the increase of the lifting weight (if the lifting weight increases to 10 tons, the deformation amount is about 0.8m), and decreases with the increase of the material's resistance to deformation (which is consistent with the pattern of preferred scheme 7).
[0112] 7. Step S6: Calculate the actual height of the boom end point
[0113] Based on the theoretical height (12.2m) obtained in step 4, subtract the elastic deformation (0.65m) calculated in step 5 to obtain the actual height of the boom end point after considering deformation: 12.2m-0.65m=11.55m. This height truly reflects the actual position of the boom end point under the current working conditions (due to elastic deformation, the actual height is lower than the theoretical height).
[0114] 8. Step S7: Calculate the real-time lifting height of the hook.
[0115] 8.1 The length of the wire rope released is the distance the hook travels.
[0116] Based on the pulley block's characteristic parameters (ratio 4), the ratio of the wire rope's extended length to the hook's movement distance is 4:1. Therefore: Hook descent distance = Real-time extended wire rope length ÷ Ratio = 8.4m ÷ 4 = 2.1m
[0117] 8.2 Calculate the lifting height
[0118] Subtracting the hook descent distance (2.1m) from the actual height of the boom tip (11.55m), the real-time lifting height of the hook above the ground is: 11.55m - 2.1m = 9.45m.
[0119] 8.3 Real-time updates and verification
[0120] The crane control system updates the above calculation results every 100ms (corresponding to a 10Hz acquisition frequency). At the same time, the actual hook height is measured to be 9.4m using a laser rangefinder (installed next to the pulley block at the end of the boom, pointing towards the hook). The calculation error is only 0.05m, which meets the accuracy requirements of engineering operations (allowable error ±0.1m).
[0121] Summary of Implementation Results
[0122] Through the operation of this embodiment, the 25-ton truck crane achieved accurate calculation of the hook lifting height under the conditions of 8 tons lifting load, 28℃ ambient temperature, and 35° elevation angle:
[0123] The problem of elevation angle deviation in non-horizontal luffing was solved: the trajectory deviation of the boom end height was corrected through geometric modeling;
[0124] The effect of boom elastic deformation was compensated: the 0.65m correction of deformation avoided the safety hazard of "the calculated height being higher than the actual height";
[0125] Adaptable to dynamic working conditions: The 10Hz acquisition and update frequency ensures that there is no lag in the calculation when luffing and hoisting are performed synchronously.
[0126] This implementation method can be directly applied to similar non-horizontal luffing single-boom cranes, requiring only adjustment of the structural parameters in step 1 (such as boom length, cylinder position, etc.). It has strong versatility and low engineering cost.
[0127] It is worth noting that the entire device is controlled by a master control button. Since the device matched with the control button is a common device and belongs to existing mature technology, its electrical connection relationship and specific circuit structure will not be described in detail here.
[0128] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane, characterized in that, Includes the following steps: S1. Pre-collect the structural parameters of the crane, which include at least the boom hinge point height above the ground, boom design length, luffing cylinder related parameters, boom material property parameters, boom cross-sectional property parameters, pulley block property parameters, and initial angle parameters. S2. Real-time acquisition of the crane's operating parameters, including at least the real-time change in the length of the luffing cylinder, the weight of the hoisted load, and the real-time release length of the wire rope. S3. Based on the luffing cylinder correlation parameters in step S1 and the real-time length change of the luffing cylinder in step S2, the real-time elevation angle of the boom to the horizontal plane is derived through geometric modeling. S4. Based on the boom hinge point height above the ground in step S1, the boom design length, and the real-time elevation angle in step S3, calculate the theoretical height of the boom endpoint. S5. Based on the boom material properties and cross-sectional properties obtained in step S1 and the lifting weight obtained in step S2, calculate the elastic deformation at the boom end. S6. Based on the theoretical height from step S4 and the elastic deformation from step S5, calculate the actual height of the boom end point. S7. Based on the pulley block characteristic parameters of step S1, the real-time release length of the wire rope in step S2, and the actual height in step S6, calculate the real-time lifting height of the hook.
2. The method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane according to claim 1, characterized in that, In step S1, the associated parameters of the variable amplitude cylinder include: The relative position of the hinge point on the turntable of the luffing cylinder and the hinge point on the boom in the horizontal direction, that is, the straight-line distance measured along the horizontal reference plane; The relative position of the hinge point on the turntable of the luffing cylinder and the hinge point on the boom in the vertical direction, that is, the straight-line distance measured in the vertical direction; The fixed distance between the boom side hinge point and the boom hinge point of the luffing cylinder is the straight-line length of the two hinge points under the design state. The initial length of the luffing cylinder is the total length between the hinge points at both ends of the cylinder when the boom is at its minimum working angle.
3. The method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane according to claim 1, characterized in that, In step S1, the boom material property parameters include the inherent property of the material itself resisting elastic deformation, which varies with the type of material; The boom section characteristic parameters include bending resistance parameters determined by the cross-sectional shape and size, which vary with different cross-sectional designs; The characteristic parameters of the pulley block include the ratio between the moving distance of a single section of wire rope and the corresponding moving distance of the hook, which is determined by the structural design of the pulley block. The initial angle parameter includes the angle between the boom axis and the vertical direction when the luffing cylinder is in its initial state. This angle is fixed by the crane structural design.
4. The method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane according to claim 1, characterized in that, In step S2, the operating parameters also include the ambient temperature, i.e. the real-time temperature of the environment where the boom is located; In step S5, the inherent properties of the material resisting elastic deformation are adjusted according to the difference between the ambient temperature and the standard temperature, so that the amount of elastic deformation is adapted to the actual properties of the material at the current temperature.
5. The method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane according to claim 1, characterized in that, In step S3, the geometric modeling process specifically includes: With the boom hinge point as fixed point A, the luffing cylinder turntable side hinge point as fixed point B, and the luffing cylinder boom side hinge point as dynamic point C, construct triangle ABC; Wherein, the length of AB is determined by the horizontal and vertical relative positions in step S1, the length of AC is the fixed distance between the boom side hinge point and the boom hinge point in step S1, and the length of BC is the sum of the initial length in step S1 and the real-time length change in step S2. Derivation of angle parameters based on the relationship between the lengths of the three sides of triangle ABC.
6. The method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane according to claim 5, characterized in that, The angle calculation rule is as follows: Based on the lengths of the three sides of triangle ABC, calculate the included angle at point A, that is, the angle between AB and AC; superimpose this included angle with the initial angle parameter in step S1 to obtain the real-time elevation angle of the boom to the horizontal plane. The superposition relationship is determined by the structural design of the crane and reflects the combination relationship between fixed angles and dynamic angles.
7. The method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane according to claim 1, characterized in that, In step S4, the theoretical height is calculated as follows: The vertical projection height of the boom design length is determined by the relationship between the boom design length and the real-time elevation angle; the larger the real-time elevation angle, the larger the projection height. The theoretical height is the sum of the height of the boom hinge point above the ground and the above projected height, reflecting the end point height without considering boom deformation.
8. The method for calculating the lifting height of a non-horizontal variable-amplitude single-arm crane according to claim 1, characterized in that, In step S5, the calculation of the elastic deformation is specifically as follows: The boom is simulated as a cantilever structure with one end fixed to the hinge point and the other end free, with the suspended weight acting as a load on the free end; Based on the inherent properties of the boom material's resistance to elastic deformation, the bending resistance parameters of the cross section, and the boom design length, the downward bending amount of the free end caused by the load is derived; this bending amount increases with the increase of the lifting weight and decreases with the enhancement of the material's resistance to deformation.