Mine car load test identification method

Abstract

The invention provides a mine car load test identification method, and belongs to the technical field of vehicle safety. Comprising the steps that S1, a plurality of one-way strain gauges are adopted, a quarter-bridge or half-bridge or full-bridge circuit is adopted, a strain rosette does not need to be adopted, various compensation, temperature excursion and null excursion do not need to be considered, and dynamic loads are collected in real time; s2, processing a strain signal; s3, based on the strain signal which only retains the dynamic alternating component after the strain signal processing, identifying the dynamic component of the mine car load; and S4, superposing the static or quasi-static balance load to obtain a complete load spectrum of the mine car. According to the method, a series of scientific and reasonable processing and analysis are carried out on a test result through an extremely simple test method, noise interference and various drifts can be effectively removed, error deviation is corrected, and useful information hidden in original data is fully mined. Through the test and data processing flow, the finally identified mine car load spectrum can truly reflect the actual load state of the mine car.

Description

TECHNICAL FIELD

[0001] The application provides a mine car load test identification method, and belongs to the technical field of vehicle safety. BACKGROUND

[0002] The real-time load condition of a mine car, which is a key equipment for mine transportation, is directly related to the operation safety, service life and transportation efficiency of the vehicle. Accurate identification of the load of the mine car is of great significance to vehicle performance evaluation, safety monitoring and early warning, transportation efficiency optimization and mine production management. However, the traditional mine car load identification method has many limitations in practical application.

[0003] Strain measurement or stress measurement is the basis for mine car load identification. Strain gauges, as a kind of high-precision sensors, have been widely used in the measurement of mine car strain signals. However, the strain signal often contains noise, temperature drift, zero drift, burr and other interference components, and the traditional method has deficiencies in signal filtering, zero drift processing and comprehensiveness of load identification. For example, band-pass filtering will filter out the static components in the low frequency band, resulting in data distortion; complete zero drift removal or simple and rough midline zero processing will incorrectly remove the static components, affecting the accuracy of load identification.

[0004] In recent years, although researchers have made a lot of improvements in optimizing signal filtering strategies, improving zero drift processing methods, integrating multiple software tools and introducing simulation technology, the limitations of traditional methods have not been completely solved.

[0005] The dynamic load of the rear axle of the mine car must be tested in real time, and cannot be calculated by the ADAMS whole vehicle model. Because the mine car uses large tires with a diameter of about 3 meters, such as 50 / 80R57, there is no tire dynamics test bench and test results for traditional cars, and there is no mine car tire model, so ADAMS simulation of mine car road driving cannot be performed, and therefore only real-time load testing can be performed;

[0006] Real-time load testing generally uses strain testing. Strain testing requires compensation, such as bending stress compensation, axial stress compensation, and especially temperature compensation. These compensations increase the degree of complexity and workload of strain testing, and even cannot be implemented due to structural or space limitations, such as the requirement for two strain gauges to be arranged on the symmetric two sides of the tensioned member for bending stress compensation of the axial stress test, and the requirement for four strain gauges to be arranged on the symmetric two sides of the bending member for axial stress compensation of the bending stress test. These compensations often cannot be implemented due to structural or space limitations.

[0007] Since compensation is needed for strain test, increasing compensation will make strain test more complicated or unachievable. If long time test is directly carried out without compensation, the obtained strain curve will have serious temperature drift and zero drift phenomenon, which belongs to slow varying component in strain signal close to static component, so that the test result will have overall deviation, and then affect the authenticity and effectiveness of subsequent load identification. SUMMARY

[0008] In view of the above technical problems, the present application provides a method for load test and identification of mine car, which can effectively remove noise interference and various drifts, correct error deviation and fully exploit useful information hidden in original data by means of a series of scientific and reasonable processing and analysis of test results with the aid of a simple test method. After this processing procedure, the finally identified load of mine car is not only more reasonable, but also can truly reflect the actual load state of mine car. The method has the following characteristics:

[0009] 1. Simple test: quarter bridge or half bridge or full bridge circuit test of multiple unidirectional strain gauges is adopted, without strain rosette, and without temperature compensation, axial stress test without bending stress compensation, bending stress test without axial stress compensation and other complicated compensation techniques;

[0010] 2. Simple data processing: low-pass filter is used to retain static component and low-frequency component of interest, and then the midline is set to zero to completely remove temperature drift, zero drift and direct current component, and only retain low-frequency alternating current component of interest;

[0011] 3. Load identification alternating current component: based on the retained low-frequency alternating current component of interest, the load alternating current component is identified;

[0012] 4. Static load compensation: ADAMS whole vehicle model simulation technology is used to extract load static component, and combined with typical working conditions of mine car such as empty or full load downhill, full load or empty load uphill, empty and full load flat road driving and other typical working conditions, based on the uphill and downhill sections displayed by GPS signal, the load static direct current component is superimposed on the load alternating current component respectively, and then the dynamic load spectrum of full working condition is obtained, which overcomes the shortcomings of traditional method, and realizes more accurate, comprehensive and real load identification of mine car in full working condition in a simple way, and provides a new solution for performance evaluation, safety monitoring and optimization design of mine car.

[0013] 5. In the field of mine car load identification, traditional strain gauge-based measurement methods have an inherent and difficult-to-overcome limitation: even under ideal conditions (for example, using high-precision strain gauges, effectively suppressing system zero drift, and minimizing environmental noise interference), the measurement results can only reflect the static load caused by the ore, the static or quasi-static load caused by axle load transfer when traveling up and downhill, and the static and dynamic strain caused by the dynamic load of the entire vehicle. In other words, traditional methods cannot directly and continuously obtain the static strain signal caused by the total weight of the mine car and the ore, including the weight of the mine car.

[0014] The fundamental reason is that strain gauges measure the local microstrains that occur in the mine car structure when loaded. When the mine car is unloaded and stationary, the body structure already bears the stresses generated by its own weight and the weight of its attached equipment. At this point, the strain gauge's corresponding baseline output value is zero. During subsequent loading and transportation of ore, the strain gauge cannot reflect the static load component caused by the mine car's own weight. Consequently, traditional strain measurement systems typically only effectively capture the dynamic variation, failing to effectively correlate, separate, and integrate the initial static strain component representing the vehicle's own weight with the captured dynamic strain component. Consequently, the output signal loses information about the static strain caused by the vehicle's own weight, making load identification, subsequent vehicle performance evaluation, safety monitoring and early warning, transportation efficiency optimization, and mine production management based on this information strictly unacceptable.

[0015] The core innovation of this method lies in its successful solution to the critical issue of "missing absolute total weight signal." By introducing the multi-body dynamics simulation software ADAMS, and using a high-precision physical model to calculate the static stress field of the vehicle structure under combined loads, the method can accurately identify and separate the static component of the measurement signal (primarily comprising the relatively constant load effects of the mine car's own weight and ore).

[0016] The signal output by the method of this invention is no longer simply a measurement of ore weight change; it instead produces a complete, accurate, and continuous load change signal representing the combined weight of the vehicle and the ore. This signal not only contains real-time dynamic information about the ore loading, but also firmly anchors the absolute benchmark of the vehicle's deadweight, providing an unprecedented, complete, and reliable load data foundation for critical applications such as accurate weighing of mining vehicles, safety monitoring, and efficiency statistics.

[0017] The specific technical solutions are:

[0018] A method for testing and identifying a mine car load comprises the following steps:

[0019] S1. Strain test

[0020] Adopt multiple one-way strain gauges, and adopt quarter bridge or half bridge or full bridge circuit, without adopting strain flowers, without considering various compensations, temperature drift and zero drift, real-time collection dynamic load.

[0021] S2, strain signal processing

[0022] Low-pass filtering: the original strain signal is processed by 50Hz low-pass filtering;

[0023] Complete zero drift removal: the low-pass filtered signal is completely zero drift removed, so that all signals are based on Y=0 straight line and present up and down fluctuation state, only dynamic alternating component of strain signal is reserved.

[0024] Deburring: remove wild points in the signal, reduce the adverse effects of abnormal spikes and burrs on load identification, and improve the smoothness and reliability of the signal.

[0025] S3, dynamic load identification

[0026] Based on the strain signal processing, only the dynamic alternating component of the strain signal is reserved, and the dynamic component of the mine car load is identified.

[0027] S4, superimposing static or quasi-static balance load to obtain the complete load spectrum of the mine car

[0028] Static or quasi-static balance load acquisition: the mine car model is built by means of ADAMS software; the static balance load of typical mine area working conditions such as empty load uphill, empty load and full load horizontal road driving, full load uphill and downhill is obtained based on the static balance simulation analysis of ADAMS whole car model; then based on the uphill and downhill road segments displayed by GPS signal, the static balance load of corresponding working condition is superimposed on the dynamic load of corresponding road segment identified, the complete load signal is reconstructed, and finally the mine car load spectrum containing dynamic component and static or quasi-static balance load component is obtained.

[0029] The technical scheme of the present application has the following technical effects:

[0030] (1) simple strain test

[0031] Simple test, no fear of drift: adopt multiple one-way strain gauges, and adopt quarter bridge or half bridge or full bridge circuit, without adopting strain flowers, without considering various compensations, temperature drift and zero drift, real-time collection dynamic load.

[0032] The compensation of strain test, such as bending stress compensation, axial stress compensation, especially temperature compensation, increases the complexity and workload of strain test, and even cannot be implemented due to structural or space limitations, such as the bending stress compensation of axial stress test requires two strain gauges arranged on the symmetrical two sides of the tension member, and the axial stress compensation of bending stress test requires four strain gauges arranged on the symmetrical two sides of the bending member, which cannot be implemented due to structural or space limitations.

[0033] (2) Guarantee the authenticity of data

[0034] The low-frequency dynamic alternating components of interest in the strain signal are completely retained by low-pass filtering, ensuring that the identified load signal accurately reflects the actual dynamic alternating load of the mine car, providing reliable basis for subsequent vehicle analysis.

[0035] Due to different low-frequency cutoff frequencies such as 0.3, 0.5, 0.7, 1.0 Hz, the quasi-static components gradually change from too much to too little, causing uncertainty in retaining static or quasi-static components such as sensor zero drift, temperature drift, and axle load transfer in uphill and downhill working conditions, resulting in load distortion.

[0036] (3) Comprehensive improvement

[0037] Integrating dynamic components and static components, the complete load spectrum of the mine car is obtained, providing more comprehensive data support for in-depth study of the mechanical properties of the mine car under different working conditions.

[0038] Overcomes the one-sidedness and limitations of previous methods that only focus on dynamic changes or only focus on static components.

[0039] (4) Innovative integration

[0040] Innovatively combines the advantages of Ncode software, MATLAB software, and ADAMS software and other professional software, each performs its own function and closely cooperates, forming a simple and efficient, reliable and accurate unique mine car load test and identification method and process, which is different from single software analysis or single strain test processing mode, providing an integrated innovative idea and method for solving similar engineering problems. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 X-direction strain of the rear trailing arm of the example before and after 50Hz low-pass filtering (before: red solid line; after: black dashed line);

[0042] Figure 2 X-direction strain of the rear trailing arm of the example before and after zero drift removal (before: red solid line; after: black dashed line);

[0043] Figure 3Strain comparison before and after deburring of the X direction of the rear trailing arm of the example (before: red solid line; after: black dashed line);

[0044] Figure 4 Strain comparison before and after deburring of the Z direction of the rear trailing arm of the example (before: red solid line; after: black dashed line);

[0045] Figure 5 Strain comparison before and after deburring of the Z direction of the rear trailing arm of the example (before: red solid line; after: black dashed line);

[0046] Figure 6 Strain comparison before and after deburring of the Z direction of the rear trailing arm of the example (before: red solid line; after: black dashed line);

[0047] Figure 7 f 4,x -X direction strain;

[0048] Figure 8 f 5,z -X direction strain;

[0049] Figure 9 f 4,x -Z direction strain;

[0050] Figure 10 f 5,z -Z direction strain;

[0051] Figure 11 f 4,x Load;

[0052] Figure 12 f 5,z Load;

[0053] Figure 13 Force (dynamic component) of the Z direction of the rear trailing arm under full load downhill;

[0054] Figure 14 Force of the Z direction of the rear trailing arm under full load downhill. DETAILED DESCRIPTION

[0055] The technical solutions of the present application will be described in combination with specific embodiments.

[0056] This embodiment takes the Z direction load of the rear trailing arm of a mine car under full load downhill as an example.

[0057] (1) Strain signal processing:

[0058] X direction strain data of the rear trailing arm:

[0059] ① 50Hz low-pass filtering, such as Figure 1 .

[0060] ②Zero drift removal, such as Figure 2 .

[0061] ③Deburring, such as Figure 3 .

[0062] Z direction strain data of rear trailing arm:

[0063] ①50Hz low-pass filter, such as Figure 4 .

[0064] ②Zero drift removal, such as Figure 5 .

[0065] ③Deburring, such as Figure 6 .

[0066] (2) Dynamic load identification:

[0067] As shown in Figures 7 to 12 , fix the left and right shaft heads, and sequentially apply f4=f 4,x , f5=f 5,z load at the hinge hole, and extract the specific direction strain of the two experimental patches to obtain the unit load strain matrix required for hinge load identification:

[0068] A e-f,b (1:2,1:2)=[19.992,36.589;

[0069] -3.2382,5.7679]*1.0e-11.

[0070] X and Z direction load identification calculation process of rear trailing arm:

[0071] Test to obtain patch strain e4, e5, and identify the load expression:

[0072] [F4,F5] T =A e-f,b -1 ·[e4,e5] T

[0073] Import this formula into MATLAB and calculate with the previously processed strain signal, thus obtaining the dynamic component part of the load, as shown in Figure 13 .

[0074] (3) Obtain static load:

[0075] According to the ADAMS model simulation, the static component of the rear trailing arm in the Z direction is 257.1 tons when the mine car is full and downhill (2247s-2400s).

[0076] (4) Superimpose dynamic load and static load to obtain complete load signal, as shown in Figure 14 .

Claims

1. A method for testing and identifying a mine car load spectrum, characterized in that: The following steps are involved: S1. Strain test Multiple unidirectional strain gauges are used, and quarter-bridge, half-bridge, or full-bridge circuits are adopted. There is no need to use strain gauges, and there is no need to consider various compensation, temperature drift, and zero drift. Dynamic loads can be collected in real time. S2. Strain signal processing Including low-pass filtering, complete zero drift removal, and burr removal; S3. Dynamic load identification Based on the strain signal processing that only retains the dynamic alternating component, the dynamic component of the mine car load is identified; S4. Superimpose static or quasi-static balanced loads to obtain the complete load spectrum of the mine car.

2. A method for testing and identifying a mine car load according to claim 1, characterized in that: The specific method of strain signal processing in S2 is: Low-pass filtering: 50Hz low-pass filtering is used to process the original strain signal; Complete zero drift removal: Perform a complete zero drift removal operation on the low-pass filtered signal, so that all signals fluctuate up and down based on the Y=0 straight line, and only retain the dynamic alternating component of the strain signal; Deburring: Removes wild points in the signal, reduces the adverse effects of abnormal spikes and other burrs on load identification, and improves signal smoothness and reliability.

3. The method for testing and identifying a mine car load according to claim 1, wherein: The method for obtaining static or quasi-static balanced load in S4 is: A mine car model was built with ADAMS software. Based on the static balance simulation analysis of the ADAMS vehicle model, the static balance loads of typical mining conditions such as empty uphill and downhill, empty and fully loaded horizontal road driving, and fully loaded uphill and downhill driving were obtained. Then, based on the uphill and downhill sections displayed by the GPS signal, the static balance load of the corresponding working condition is superimposed on the dynamic load of the identified corresponding section to reconstruct the complete load signal, and finally a mine car load spectrum containing both dynamic components and static or quasi-static balance load components is obtained.

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