Hoisting load measuring method based on balance beam strain-load relation

Abstract

According to the balance beam strain-load relation-based hoisting load measurement method, strain-load values of key points of a balance beam are measured to obtain a least square fitting curve of a required working condition, so that the hoisting load of the balance beam is effectively measured. According to the balance beam surface strain hoisting load measuring system provided by the embodiment of the invention, the same strain sensors are respectively arranged at the four position points with relatively large strain of the balance beam, the strain values are acquired, and finally, calculation is performed through a corresponding formula, so that the effect of monitoring the hoisting load of the balance beam in real time is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of lifting weight measurement, and particularly relates to a lifting weight measurement method based on the strain-load relationship of a balance beam. Background Art

[0002] The size of the rotor of a large hydropower station is relatively large. In this example, the diameter of the rotor of the hydropower station is 15 m, the height is 3 m, and the weight is more than 1000 t. During the hoisting process of the hydropower station rotor, it is necessary to use a large bridge crane to complete the hoisting of the rotor through a special lifting tool, lift the rotor from the maintenance workshop to above the foundation pit, and then complete the assembly of the hydraulic generator rotor and the stator.

[0003] The balance beam is located at the interface between the hoisting equipment and the hoisting object, connecting the overhead crane and the rotor, and plays an important role in the rotor hoisting operation. Its main functions include: ensuring that the rotor remains balanced and stable during the hoisting process, avoiding damage to the rotor caused by tilting or rotation, which is crucial for ensuring the safety of the hoisting operation and the integrity of the equipment.

[0004] Reasonably distribute or balance the loads of each lifting point. In the case of multi-crane lifting, the balance beam reasonably distributes or balances the loads of each lifting point to ensure the stability and safety of the hoisting operation. Therefore, when performing the rotor hoisting operation, it is very necessary to use a balance beam for lifting the rotor.

[0005] When the balance beam hoists heavy objects, it is easy to be dangerous due to exceeding the load borne by the balance beam. The potential safety risks cannot be ignored, so it is very necessary to measure the load of the balance beam to ensure the normal progress of the hoisting. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a lifting weight measurement method based on the strain-load relationship of a balance beam. The present invention determines the key parts of the balance beam structure through finite element simulation, and arranges strain sensors at these parts, which can accurately capture the strain response of the balance beam under different loads.

[0007] To solve the above technical problem, the technical solution adopted by the present invention is: A lifting weight measurement method based on the strain-load relationship of a balance beam, the steps are as follows: S1. Install strain sensors at the key parts of the balance beam structure, and obtain the strain data of the balance beam structure under different loads in actual situations through the arranged strain sensors; The method for obtaining the key parts of the balance beam structure is: determining the key parts through finite element simulation, and finding the parts with larger strain in the hoisting device under the hoisting working conditions considering acceleration and inclination. These parts are the key parts; S2. Sum the strain values of multiple key parts, fit the relationship curve between the strain values of the key parts and the load, and obtain the strain-load relationship formula; S3. During the service process of the structure, use the strain sensors arranged on the key parts of the structure to obtain the strain data at the same position at the same time interval, and use the obtained strain data as the input of the calculation formula in step S2 to output the weight borne by the structure, realizing the online monitoring of the load.

[0008] Preferably, in S1, through finite element simulation, it is determined that the four parts where the strain of the hoisting device is greater than under the hoisting conditions with acceleration and inclination are used as the key parts of the balance beam structure, and strain sensors are arranged on the key parts of the balance beam structure.

[0009] Preferably, the process of obtaining the strain values of the key parts is as follows: under the conditions that the load of the balance beam is vertically downward, the load deflects 5° in the short side direction of the balance beam, and the load deflects 5° in the long side direction of the balance beam, obtain the strain values under different loads.

[0010] Preferably, in step S2, after selecting the method of summing the measured point strains to obtain the total strain, then perform fitting, and magnify the strain values of the key parts by 10 5 times and obtain the measured point summation from the image to reduce the influence of load deflection on the measurement of the load size.

[0011] Preferably, the sub-steps of S2 are as follows: Construct a simulation database, and the simulation database includes data samples under different working conditions. The data values of the data samples include strain values and load magnitudes; Through finite element simulation of the overall structure of the balance beam, determine the parts where the strain of the hoisting device changes greatly under the hoisting conditions with acceleration and inclination, and arrange strain sensors on these parts. The designed working condition is N; Collect the corresponding strain data y under each working condition, including the strain values measured at each point by the strain bridge, and obtain the strain vector of the measured points =[ε1 ε2 ε3... ε k , where ε k represents the strain value measured by the strain measurement point numbered k, and sum all the strain values to obtain the total strain y.

[0012] Preferably, the data sample consists of the total strain value y of the measured points and the load x under the same calibration working condition.

[0013] Preferably, when the load deflects 5° towards the short side of the balance beam, the strain values at four points under simulated loads of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed up, and the relational expression of the load-strain fitting curve is obtained by least squares fitting as follows: 。

[0014] Preferably, when the load deflects 5° towards the long side of the balance beam, the strain values at four points under simulated loads of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed up, and the relational expression of the load-strain fitting curve is obtained by least squares fitting as follows: 。

[0015] Preferably, when the load direction is vertically downward, the strain values at four points under simulated loads of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed up, and the relational expression of the load-strain fitting curve is obtained by least squares fitting as follows: 。

[0016] Preferably, the final strain-load relational expression is as follows:

[0017] where x is the load, with the unit of t, and f(x) is the sum of the strain values at four measuring points, with the unit of ε.

[0018] The present invention can achieve the following beneficial effects: 1. By finite element simulation, the key parts of the balance beam structure are determined, and strain sensors are arranged at these parts, enabling accurate capture of the strain response of the balance beam under different loads. Combining with the fitting of the strain-load relational expression, high-precision measurement of the lifting load is achieved, with the measurement error controlled within 5%, significantly improving the safety and reliability of the lifting operation.

[0019] 2. By arranging strain sensors at the key parts and collecting strain data at fixed time intervals, real-time online monitoring of the balance beam load is achieved. This method can promptly detect abnormal loads and avoid equipment damage or safety accidents caused by overloading or eccentric loading.

[0020] 3. The present invention considers various hoisting working conditions (such as the load being vertically downward, deflecting 5° towards the short side, and deflecting 5° towards the long side), and through finite element simulation and experimental verification, establishes a strain-load relationship formula applicable to different working conditions. This method can effectively handle the complex working conditions in actual hoisting operations and ensure the accuracy and stability of the measurement results.

[0021] 4. By summing the strains at the measuring points and amplifying the strain values at the key positions, the present invention can effectively reduce the influence of load deflection on the measurement results and improve the anti-interference ability and adaptability of the measurement system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below in conjunction with the drawings and embodiments: Figure 1 It is a flow chart of the method of the present invention.

[0023] Figure 2 It is a diagram of the positions of four simulation measuring points in the method of the present invention.

[0024] Figure 3 It is the load-strain fitting curve of measuring point 3 in the present invention.

[0025] Figure 4 It is the load-strain fitting curve of measuring point 4 in the present invention.

[0026] Figure 5 It is the load-strain fitting curve of measuring point 5 in the present invention.

[0027] Figure 6 It is the load-strain fitting curve of measuring point 6 in the present invention.

[0028] Figure 7 It is the strain-load fitting curve of the sum of the strains of measuring points 3, 4, 5, and 6 in the present invention. SPECIFIC EMBODIMENTS

[0029] The preferred solution is as Figures 1 to 7 shown. In order to implement a load measurement method based on the strain-load relationship of the balance beam, the specific measures are as follows: The introduction of the acquisition device is as follows: Four strain sensors collect data. The four strain sensors are arranged at specific positions, and the above sensor acquisition module can sense the stress and strain of the balance beam; Two data acquisition devices. The data acquisition devices are arranged in the power supply cabinet. The above data acquisition devices can collect the sensed data of the corresponding sensor acquisition module and transmit the sensed data; A controller. The controller communicates with the two data acquisition devices through signal transmission lines.

[0030] The host computer communicates with the controller via a signal transmission line, enabling communication between the host computer and the controller and performing fusion calculations on the data sent by the controller. Programming is carried out using Unity3D software. After receiving the fused data from the host computer, the fused data is resolved and analyzed, presenting the strain perception information of the twelve groups of sensor acquisition modules and the real-time information of the load, thereby intuitively showing the stress and strain of the balance beam and the real-time state of the suspended load to the bridge crane driver.

[0031] Optionally, the construction process of the strain-load relationship includes: Construct a simulation database, which includes data samples under different working conditions. The data values of the samples include strain values and load magnitudes.

[0032] Perform a force analysis on the structure in finite element software such as ANSYS. By setting the load conditions and working conditions, the corresponding load simulation results are obtained. According to the simulation results, determine the positions where the structural strain changes significantly and set them as strain monitoring points; and paste strain sensors on the surfaces of these positions, with the number of pasted sensors being 4. Then start the structural loading experiment and set 3 different load conditions according to the actual service conditions of the structure. Collect the strain data under each working condition, including the strain values measured at each point by the strain bridge. Obtain the strain vector of the measuring points =[ε1 ε2ε3...εk], where εk represents the strain value measured at the strain measuring point numbered k, and the sum of all strain values is obtained as the total strain.

[0033] The load parameter vector of the load measurement method based on the strain-load relationship of the balance beam is the total weight magnitude.

[0034] Furthermore, the data samples of the load measurement method based on the strain-load relationship of the balance beam are composed of the total strain value y of the measuring points under the same calibration working condition and the load x.

[0035] After magnifying the strain of the measuring points by 10 5 times, the summation of the measuring points obtained from the image can reduce the influence of load deflection on the measurement of the load magnitude. Therefore, the method of summing the strain of the measuring points is selected to obtain the total strain and then fitting is carried out.

[0036] Furthermore, when the load deflects 5° in the direction of the short side of the balance beam, the strain values of four points under the simulation loads of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed, and the relationship formula of the load-strain fitting curve is obtained by least squares fitting as:

[0037] Furthermore, when the load deflects 5° in the long side direction of the balance beam, the strain values at four points under simulation loads of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed up, and the relational expression of the load-strain fitting curve is obtained by least squares fitting as follows:

[0038] Furthermore, when the load direction is vertically downward, the strain values at four points under simulation loads of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed up, and the relational expression of the load-strain fitting curve is obtained by least squares fitting as follows:

[0039] Furthermore, the final strain-load relational expression is:

[0040] where x is the weight in t, and f(x) is the sum of the strain values at four measuring points in ε.

[0041] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The protection scope of the present invention should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, the equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for measuring a weight based on a balance beam strain-load relationship, characterized in that The following steps are involved: S1. Install strain sensors at key positions of the balance beam structure, and obtain strain data of the balance beam structure under different loads in actual situations through the arranged strain sensors; The key parts of the balance beam structure are obtained by: determining the key parts through finite element simulation, and finding the parts with large strain in the lifting device under the lifting conditions with acceleration and inclination, which are the key parts; S2, summing the strain values ​​of multiple key parts, fitting the relationship curve between the strain value and load of the key parts, and obtaining the strain-load relationship; S3. During the service of the structure, strain sensors arranged at key parts of the structure are used to obtain strain data at the same position at the same time intervals. The obtained strain data is used as the input of the calculation formula in step S2 to output the weight borne by the structure, thereby realizing online monitoring of the load.

2. A method for measuring a weight based on a balance beam strain-load relationship according to claim 1, characterized in that: In S1, through finite element simulation, it is determined that the strain of the lifting device under the lifting condition with acceleration and inclination is greater than The four positions are regarded as the key positions of the balance beam structure, and strain sensors are arranged at the key positions of the balance beam structure.

3. The method for measuring a weight based on a balance beam strain-load relationship according to claim 2, characterized in that: The process of obtaining the strain values ​​of key parts is as follows: when the load of the balance beam is vertically downward, the load is deflected 5° toward the short side of the balance beam, and the load is deflected 5° toward the long side of the balance beam, the strain values ​​under different loads are obtained.

4. The method for measuring a weight based on a balance beam strain-load relationship according to claim 1, characterized in that: In step S2, the total strain is obtained by summing the strains of the measuring points and then fitting is performed. The sum of the strain values ​​of the key parts is amplified by 10 5 The image is multiplied and the sum of the measuring points is obtained to reduce the influence of load deflection on the load size measurement.

5. The method for measuring a weight based on a balance beam strain-load relationship according to claim 1, characterized in that: The sub-steps of S2 are as follows: Constructing a simulation database, wherein the simulation database includes data samples under different working conditions, and data values ​​of the data samples include strain values ​​and load magnitudes; By performing finite element simulation on the overall structure of the balance beam, the parts where the strain of the hoisting device changes greatly under the hoisting conditions with acceleration and inclination are determined, and strain sensors are arranged at these parts. The design condition is N; The corresponding strain data under each working condition is collected as y, which includes the strain value of each point measured by the strain bridge, and the strain vector of the measuring point is obtained. =[ε1ε2ε3...ε k ], where ε k Represents the strain value measured at the strain measuring point numbered k. The total strain y is obtained by summing up all the strain values.

6. The method for measuring a weight based on a balance beam strain-load relationship according to claim 5, characterized in that: The data sample consists of the total strain value y and load x of the measuring point under the same calibration condition.

7. The method for measuring a weight based on a balance beam strain-load relationship according to claim 3, characterized in that: When the load is deflected 5° toward the short side of the balance beam, the strain values ​​of the four points under the simulated load of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed, and the relationship between the load and strain fitting curve is fitted by the least squares method: 。 8. The method for measuring a weight based on a balance beam strain-load relationship according to claim 7, characterized in that: When the load is deflected 5° toward the long side of the balance beam, the strain values ​​of the four points under the simulated load of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed, and the relationship between the load and strain fitting curve is fitted by the least squares method: 。 9. The method for measuring a weight based on a balance beam strain-load relationship according to claim 8, characterized in that: When the load direction is vertically downward, the strain values ​​of the four points under the simulation load of 0t, 180t, 360t, 540t, 720t, 900t, 1080t, 1260t, 1440t, 1620t, and 1800t are summed, and the relationship between the load and strain fitting curve is fitted by the least squares method: 。 10. The method for measuring a weight based on the strain-load relationship of a balance beam according to claim 9, characterized in that: The ultimate strain-load relationship is: Where x is the load, the unit is t, and f(x) is the sum of the strain values ​​at the four measuring points, the unit is ε.

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