Spoke type track wheel continuous force measurement and solving method

Abstract

The application provides a spoke rail wheel continuous force measurement and calculation method, and relates to the wheel rail force measurement technical field.The method comprises the following steps: evenly arranging multiple strain gauges connected into a bridge circuit on a spoke rail wheel; outputting a signal through the bridge circuit; calculating strain distribution under unit vertical force and obtaining actual vertical force under external force; superimposing and correcting the bridge circuit output signal to obtain a lateral force, and completing continuous force measurement and calculation of the spoke rail wheel. Through data collection on the rail wheel and optimization of the calculation algorithm, the force measurement device can quickly respond to changes in the wheel rail force, realize continuous measurement of the wheel rail force, ensure real-time and accuracy of the test data, and be suitable for various research scenes such as railway vehicle dynamics test.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wheel-rail force measurement, and particularly relates to a spoke type track wheel continuous force measurement and solving method. BACKGROUND

[0002] With the development of railway transportation technology, wheel-rail force, as an important parameter for measuring the running state of railway vehicles, the health condition of tracks and the safety performance of trains, has attracted widespread attention. Wheel-rail force refers to the interaction between the wheel and the rail. This force is transmitted to the bogie and the car body through the suspension system of the wheel, and has a direct impact on the lateral stability, riding comfort, wheel-rail wear and derailment safety of the vehicle. The size of the wheel-rail force not only affects the safety and comfort of the vehicle, but also has an important effect on the service life of the track and the maintenance frequency.

[0003] The current mainstream wheel-rail force measurement methods include the force measuring wheel pair method based on axle strain, the measurement method based on rail waist strain, and the non-contact method for indirectly measuring wheel-rail force.

[0004] In the laboratory, strain gauges are often arranged at specific positions of the wheel or axle to realize real-time measurement of wheel-rail force, which is a relatively mature traditional force measurement method for measuring the interaction between the wheel and the rail.

[0005] The core of this method is to convert the physical strain received by the wheel into an electrical signal using a strain gauge, and then calculate the interaction between the wheel and the rail. However, in actual application, there are still some obvious shortcomings and limitations, as follows:

[0006] Low applicability. The traditional wheel-rail force measurement method has certain limitations in measuring different speeds, vehicle types and frequencies. Since the strain gauge must be arranged at a specific position of the wheel or axle, the wheel structure and material of different vehicle types are different, making it difficult for the traditional wheel-rail force measurement method to be used universally on different types of vehicles. In the measurement process of high-speed trains, the traditional wheel-rail force measurement method may also be affected by the high-speed changes of the wheel-rail contact point, and cannot accurately capture real-time changing mechanical data.

[0007] Low measurement sensitivity. In the traditional wheel-rail force measurement method, although the strain gauge can capture the change of wheel-rail force, the strain of the web plate type wheel under vertical force is small and the sensitivity is low, resulting in insufficient precision of the strain gauge in vertical force measurement, which cannot accurately reflect the actual interaction between the wheel and the rail, and cannot accurately capture the dynamic characteristics of the vehicle during high-speed motion.

[0008] The phase angle calculation leads to large errors. In the existing traditional wheel-rail force measurement method, the phase angle information of the wheel-rail contact point is usually ignored when calculating the wheel-rail force. This means that the traditional wheel-rail force measurement method can only obtain the amplitude information of the strain signal and cannot reflect the actual force direction and angle change of the wheel during rotation. Since the wheel-rail force is a dynamic quantity, ignoring the phase angle information may lead to insufficient accuracy of the calculation results, especially in high-speed trains, such error is more obvious. In addition, due to the limitations of the installation position of the strain gauge and the complexity of the wheel material, the wheel-rail force calculated by the traditional wheel-rail force measurement method may have significant deviation from the actual force, which cannot meet the high-precision engineering application requirements.

[0009] The test installation is complex. The traditional wheel-rail force measurement method requires installing strain gauges at key positions of the axle or wheel, and this installation process is usually cumbersome and requires highly accurate calibration. When measuring the wheel-rail force of different vehicle types, it is necessary to repeatedly install, adjust and calibrate the strain gauges, which greatly increases the complexity and cost of the test. In addition, the running environment of the wheel and axle is complex, which may affect the stability of the strain gauge and cause measurement errors.

[0010] The strain gauge is easily damaged. Due to the complex dynamic load on the wheel and axle during the test, the strain gauge is easily affected by factors such as vibration, impact and temperature change, especially under random load conditions, the service life and stability of the sensor will be severely affected. Such damage may result in inaccurate measurement data, increasing the maintenance cost of the equipment.

[0011] In summary, although the traditional measurement method solves the problem of wheel-rail force measurement to some extent, it has many limitations. First, the traditional method requires installing a large number of sensors on the vehicle axle or track, the measurement process is complex, the test cost is high, and the installation and calibration are not convenient. Second, since the contact point of the wheel and the track changes constantly with the rotation of the wheel, real-time measurement of the force at the wheel-rail contact point is extremely challenging. During the test, the dynamic changes of the wheel-rail contact point are simulated to ensure the accuracy of the wheel-rail force measurement.

[0012] Therefore, there is an urgent need for a wheel-rail force continuous measurement and calculation method with high precision and simple operation to better meet the high-precision measurement requirements of wheel-rail force in tests. SUMMARY

[0013] In view of the above problems in the prior art, the present application provides a spoke-type track wheel continuous force measurement and calculation method to solve the above problems.

[0014] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: a spoke-type track wheel continuous force measurement and calculation method applied to a track wheel force measurement device, comprising the following steps:

[0015] A plurality of strain gauges are evenly arranged on the spoke type track wheel and connected into a bridge circuit; the bridge circuit outputs a signal, the strain distribution under unit vertical force is calculated, and the actual vertical force under external force is obtained; the lateral force is obtained by superimposing and correcting the bridge circuit output signal, and the continuous force measurement and calculation of the spoke type track wheel are completed.

[0016] Further, the plurality of strain gauges are evenly arranged on the track wheel and connected into a bridge circuit, a vertical force measurement bridge circuit: a plurality of strain gauges are arranged at the inflection points of the spoke plate to obtain strain changes under vertical force, wherein the strain gauges are connected by a full-bridge circuit; a lateral force measurement bridge circuit: a plurality of strain gauges are arranged at the end of the spoke plate and the straight plate to eliminate the interference of vertical force on lateral force measurement.

[0017] Further, the track wheel force measuring device comprises a track wheel and a strain gauge; the spoke plate of the track wheel adopts a half-spoke design, and a fan-shaped opening is arranged on the spoke plate.

[0018] The beneficial effects of the present application are:

[0019] The present application is based on track wheel force measuring device and phase angle calculation technology, and by reasonably arranging strain gauges on the spoke plate, the wheel-rail force at the contact between the wheel and the track can be accurately measured, especially in the measurement of vertical force and lateral force, which has extremely high sensitivity and accuracy. The present application not only can simplify the test process, reduce the repeated installation of test equipment, but also can improve the measurement accuracy, reduce the test cost, and provide more reliable wheel-rail force measurement data. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The opening scheme diagram for the track wheel.

[0021] Figure 2 The fan-shaped opening optimization diagram for the track wheel.

[0022] Figure 3 The strain gauge position and bridge circuit diagram.

[0023] Figure 4 The strain distribution diagram under unit vertical force.

[0024] Figure 5 The strain distribution diagram under lateral force and bending moment.

[0025] Figure 6 The measurement point arrangement and bridge circuit diagram.

[0026] Figure 7 The result comparison diagram under unit load.

[0027] Figure 8The figure is a schematic diagram of the result comparison under the action of random load (without eccentric distance).

[0028] Figure 9 The figure is a schematic diagram of the result comparison under the action of random load (with eccentric distance).

[0029] Figure 10 The figure is a schematic diagram of the influence of eccentric distance on the measurement of wheel-rail force.

[0030] Figure 11 The figure is a flow chart of the method of the present application. DETAILED DESCRIPTION

[0031] The specific embodiments of the present application are described below to facilitate the understanding of the present application for those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the present application defined and determined by the appended claims, and all the inventions utilizing the concept of the present application are within the scope of protection.

[0032] EMBODIMENT

[0033] As shown in Figure 11 The present application provides a spoke rail wheel continuous force measurement and calculation method, which is applied to a rail wheel force measurement device, and the implementation method is as follows:

[0034] S1, a plurality of strain gauges connected in a bridge circuit are uniformly arranged on the spoke rail wheel, specifically:

[0035] The vertical force measurement bridge circuit: a plurality of strain gauges are arranged at the inflection points of the spoke plates to obtain the strain change under the action of vertical force, wherein the strain gauges are connected through a full-bridge circuit;

[0036] The horizontal force measurement bridge circuit: a plurality of strain gauges are arranged at the ends of the spoke plates and the straight web plates to eliminate the interference of vertical force on the measurement of horizontal force;

[0037] S2, the strain distribution under the action of unit vertical force is calculated by the bridge circuit output signal, and the actual vertical force under the action of external force is obtained;

[0038] S3, the horizontal force is obtained by superimposing and correcting the bridge circuit output signal, and the continuous force measurement and calculation of the spoke rail wheel are completed.

[0039] In this embodiment, the rail wheel force measurement device rail wheel and the strain gauges; the strain gauges are arranged on the rail wheel.

[0040] The spoke plate of the track wheel adopts a half-spoke design, and an opening is arranged on the spoke plate; the strain gauge is arranged at the reverse bending point of the spoke plate; the strain gauge is arranged at the end of the spoke plate and the straight web plate; the opening on the spoke plate is a sector.

[0041] In this embodiment, the track wheel force measuring device of the present application constructs a high-precision, stable and sensitive wheel-rail force measuring system by designing the track wheel and strain gauge arrangement. This system can continuously measure and calculate the wheel-rail force under complex conditions such as random load and considering eccentricity, and improve the measurement accuracy through phase angle solving technology, and is suitable for various research scenarios such as railway vehicle dynamics test. The specific structure is as follows:

[0042] The track wheel is one of the core components of the force measuring device, and its main function is to simulate the contact relationship between the wheel and the track, and measure the wheel-rail force through the strain gauge. The design of the track wheel is based on the principle of "assuming that the wheel is stationary and the track rotates around the wheel", which simplifies the mechanical analysis in the test process and improves the measurement accuracy.

[0043] The track wheel is forged from track steel, and the rim part is designed with a 1:40 inclination angle to simulate the working state of the real wheel on the track. The spoke plate of the track wheel adopts a half-spoke design, and openings are arranged at key positions to improve the sensitivity of the strain signal. The shape of the opening is precisely designed to increase the strain signal output while maintaining the structural strength of the track wheel.

[0044] The outer surface of the track wheel is uniformly distributed with multiple strain gauges for measuring the changes of wheel-rail force in different directions. Through signal collection and processing of these strain gauges, the mechanical action of the wheel in the vertical, lateral and longitudinal directions can be calculated.

[0045] In this embodiment, the optimization design of the half-spoke type force measuring track wheel of the present application mainly focuses on the following four aspects: opening scheme optimization, opening sector optimization, and strength calculation of the track wheel with optimized sector opening. These optimization designs aim to improve the strain sensitivity and structural strength of the track wheel during wheel-rail force measurement, while ensuring its sufficient load capacity and reliability under high load.

[0046] 1. Opening scheme optimization

[0047] Problem with existing spoke plate design: In traditional spoke plate design, the spoke plate is usually solid, which shows small radial strain under high load, resulting in insufficient measurement sensitivity. When the force is small, the spoke plate strain is not obvious, and sufficient strain signal cannot be obtained, affecting the accuracy of the measurement. Therefore, it is necessary to increase the output signal of the strain by opening holes on the spoke plate, so as to improve the measurement sensitivity.

[0048] Optimization process: In order to improve the output of strain signal, the present application makes a hole in the spoke plate, as shown in Figure 1 The finite element analysis is used to compare the strain and stress distribution of the spoke plate under the conditions of no hole and different hole conditions. The results show that the radial strain of the spoke plate under the action of vertical force is very small, and it is difficult to capture enough signal through the strain gauge, so the sensitivity is low. Therefore, the scheme of making appropriate hole in the spoke plate is adopted to increase the output of strain signal.

[0049] The finite element results are as follows: under the action of vertical force Q=10kN, the radial strain of the spoke plate after hole making is obviously increased. The specific data shows that the radial strain of the spoke plate without hole is 3.1με, while after hole making, the radial strain increases to 7.7με, as shown in Table 1. In addition, the maximum radial stress under the action of transverse force Y=10kN increases from 16.4MPa to 17.4MPa, although it increases, but still lower than the safety limit of 18MPa, therefore, the hole making scheme is considered to be feasible.

[0050] Table 1 results of force analysis of no hole and hole making scheme

[0051]

[0052] 2, optimization of hole fan

[0053] Traditional spoke plate design problem: although the hole making of spoke plate can improve the strain output, the shape, size and position of hole making have important influence on the sensitivity of strain signal. The traditional circular hole design has limited effect on the amplification of strain signal, especially under the action of transverse force, stress concentration is easy to occur at the hole making place, which affects the structural strength of spoke plate.

[0054] Optimization process: in order to solve this problem, the present application further optimizes the hole shape of spoke plate, as shown in Figure 2 By comparing the strain distribution of circular and fan-shaped hole, it is found that the fan-shaped hole can more effectively amplify the strain signal, and at the same time reduce the stress concentration phenomenon under the action of transverse force.

[0055] Finite element results: as shown in Table 2, after the hole shape is changed from circular to fan-shaped, the radial strain under the action of vertical force Q=10kN increases from 11.5με to 11.9με, under the action of transverse force Y=10kN, the maximum strain position is transferred from the hole making place to the middle and lower position of spoke plate, and the radial strain decreases from 97.2με to 72.7με. The maximum stress decreases from 20.3MPa to 15MPa, which is still lower than the safety limit of 18MPa, showing better mechanical properties, and the scheme is basically determined as fan-shaped hole.

[0056] Optimization results: The design of fan-shaped openings not only improves the strain output under vertical force, but also effectively reduces the stress concentration phenomenon under lateral force, ensuring the stability of the wheel disc under high load. Finite element results show that the stress distribution of the wheel disc with fan-shaped opening design under lateral force is more uniform, and the structural strength is significantly improved.

[0057] Table 2 Stress analysis results of different opening shapes

[0058]

[0059] 3. Optimized fan-shaped opening - track wheel strength design

[0060] The wheel disc needs to bear loads from different directions during actual operation, so after structural optimization, strength calculation of the optimized track wheel must be performed to ensure its safety and stability under various working conditions.

[0061] Optimization process: The optimized fan-shaped opening design is further verified by finite element analysis under vertical and lateral forces. The specific calculation method is to apply loads at different angles on the wheel disc, with an interval of 15° and 22.5° as a working condition, and calculate the equivalent stress and principal stress distribution within the range of 0°-360°. In the test, the vertical force Q = 200 kN, the lateral force Y = 80 kN, and the eccentricity E is 10 mm. The most unfavorable working condition is simulated for strength analysis.

[0062] Finite element results: The most unfavorable working condition occurs at 345°, where the vertical force, eccentricity, and lateral force act simultaneously, with the maximum equivalent stress of 182.8 MPa and the maximum principal stress of -178.2 MPa, both of which are lower than the safety limit of 200 MPa. Therefore, the optimized fan-shaped opening design can maintain sufficient structural strength and safety under high load. In each working condition, the maximum equivalent stress occurs at the smallest width of the wheel disc.

[0063] Through optimization of the opening scheme, fan-shaped opening, and strength calculation, the semi-spoke type force track wheel design of the present invention significantly improves the sensitivity of strain signals while ensuring structural strength. The optimized track wheel not only provides accurate measurement data under vertical and lateral forces, but also can withstand high loads under complex working conditions, making it suitable for various research scenarios such as railway vehicle dynamics testing.

[0064] In this embodiment, the test strain gauge arrangement and bridge design are as follows:

[0065] In the present invention, multiple strain gauges are evenly arranged at key positions of the track wheel. These strain gauges are connected into bridge circuits for measuring the changes of wheel-rail force in different directions. The principle of strain gauge arrangement is based on the results of finite element analysis, ensuring that sufficient strain signals can be captured without increasing stress concentration.

[0066] Vertical force measurement bridge circuit: Strain gauges are arranged at the inflection points of the web plate, where the strain response is obvious and can capture the strain changes under the action of vertical force. The strain gauges are connected by full-bridge circuit to ensure the accuracy of signal acquisition.

[0067] Lateral force measurement bridge circuit: Strain gauges are arranged at the end of the web plate and the straight plate, which have high sensitivity under the action of lateral force. Through specific bridge circuit design, the interference of vertical force on lateral force measurement can be eliminated, ensuring that the output signal can accurately reflect the changes of lateral force.

[0068] Figure 3 The arrangement position of strain gauges and the connection mode of bridge circuit are shown. The vertical force strain gauges are located at the inflection points to reduce the mutual interference of lateral force and vertical force output signals; the lateral force strain gauges are located at the end of the web plate, enhancing the signal sensitivity when measuring lateral force.

[0069] In this embodiment, the vertical force calculation is as follows:

[0070] Vertical force calculation principle: Through the bridge circuit output signal, the strain distribution under the action of unit vertical force can be calculated, and the actual vertical force under the action of external force can be further calculated. The calculation formula of vertical force is as follows:

[0071] 1. Bridge circuit output of unit vertical force:

[0072] When unit vertical force (1 kN) acts on the bridge circuit, as shown in Figure 4 , the signal output by the bridge circuit is:

[0073]

[0074] Through equation (1), the strain output of unit vertical force in each direction can be obtained.

[0075] 2. Correction of vertical force bridge circuit output:

[0076] By correcting the phase angle, the output of the vertical force bridge circuit is:

[0077]

[0078] This step of correction is used to eliminate the error caused by the change of phase angle.

[0079] 3. Calculation of vertical force under external load:

[0080] Under the action of Q(t), the vertical force bridge output is:

[0081] q1(θ) = Sq(θ) · Q(t) (3)

[0082] q2(θ) = Cq(θ) · Q(t) (4)

[0083] According to the measured bridge output signal, the test measured vertical force can be calculated by the following formula:

[0084]

[0085] where Q cal (t) represents the test measured vertical force, q1(θ) and q2(θ) represent the output signals of the vertical force bridge under the action of the actual vertical force Q(t), Sq(θ) represents the output signal of the bridge under the action of the unit vertical force, Cq(θ) represents the output signal of the vertical force bridge by correcting the phase angle, and ε(θ) represents the strain distribution under the action of the unit vertical force.

[0086] In this embodiment, the lateral force is calculated as follows:

[0087] Lateral force calculation principle: The calculation of lateral force involves the superposition and correction of bridge output signals to minimize signal interference between lateral force and vertical force. The key to lateral force calculation lies in capturing the strain signals under the action of lateral force through strain gage arrangement and bridge design, and correcting to obtain accurate lateral force value.

[0088] 1. Bridge output of unit lateral force:

[0089] When the unit lateral force (1 kN) acts, the output signal of the bridge is:

[0090] Syy(θ) = [ε yA (θ) - ε yB (θ) + ε yB (θ + π) - ε yA (θ + π)] (6)

[0091]

[0092] where Syy(θ) and Cyy(θ) both represent the output signals of the bridge under the action of the unit lateral force, and ε yA (θ) and ε yB (θ) both represent the inner and outer surface strain distribution under the action of the unit lateral force, as shown in (a) of Figure 5

[0093] ​2. Correction under eccentricity effect: In actual measurement process, due to eccentricity, the vertical force will also be accompanied by certain bending moment effect, so the bending moment effect needs to be corrected:

[0094] Syy(θ) = [ε yA (θ) - ε yB (θ) + ε yB (θ + π) - ε yA (θ + π)] (8)

[0095]

[0096] Wherein, Syy(θ) and Cyy(θ) both represent the output signal of the bridge under the action of unit bending moment (vertical force and eccentricity), ε ZA (θ) and ε ZB (θ) both represent the strain distribution of the inner and outer surfaces under the action of unit bending moment, such as Figure 5 (b) of FIG. 1.

[0097] 3. Calculation of lateral force:

[0098] Under the action of external load Y(t) and Q(t), the lateral force bridge output is:

[0099] y1(θ) = Syy(θ) · Y(t) + Syy(θ) · Q(t) E(t) (10)

[0100] y2(θ) = Cyy(θ) · Y(t) + Cyy(θ) · Q(t) E(t) (11)

[0101] Wherein, E(t) represents the eccentricity of the vertical force action point, y1(θ) and y2(θ) represent the signals measured by the bridge at different angles respectively.

[0102] According to the bridge output result, the actual calculation formula of the lateral force is:

[0103]

[0104] Wherein, Y cal_1 (t) represents the lateral force measured by the test, Y(t) and Q(t) represent the actual acting lateral force and vertical force respectively.

[0105] In this embodiment, the main difference between the force measurement method in the specification GB / T5599 and the innovative method of the application is that the traditional force measurement method mainly adopts non-phase angle calculation method, ignores the change of the phase angle of the wheel-rail contact point, and leads to large measurement error. In the traditional method in the specification, the strain gauge arrangement is similar to the application, and the bridge arrangement of the measuring point is shown in Figure 6(Standard GB / T5599 Appendix C), but the phase change of wheel-rail contact point is not considered in the solution process, and the calculation process is as follows:

[0106] Vertical force solution:

[0107] Bridge output under unit vertical force:

[0108]

[0109] Wherein, ε(θ) represents the hoop strain distribution of the neutral axis of the patch under the action of unit vertical force;

[0110] Therefore, under the action of Q(t), the vertical force bridge output result is:

[0111] q1G(θ)=Sq G (θ)·Q(t) (16)

[0112] q2G(θ)=Cq G (θ)·Q(t) (17)

[0113] According to the bridge output result, the vertical force measured by the test is:

[0114]

[0115] In this embodiment, the lateral force solution is as follows:

[0116] Bridge output under unit lateral force+vertical force:

[0117]

[0118]

[0119] Wherein, ε y and ε z are the strain distributions under unit lateral force and bending moment, respectively.

[0120] Therefore, under the action of external loads Y(t) and Q(t), the lateral force bridge output is:

[0121] y 1G (θ)=Syy_G(θ)·Y(t)+Sye_G(θ)·Q(t)E(t) (23)

[0122] y 2G (θ)=Cyy_G(θ)·Y(t)+Cye_G(θ)·Q(t)E(t) (24)

[0123] According to the bridge output result, the lateral force measured by the test is:

[0124]

[0125] In this embodiment, the rail wheel wheel rail force calculation method of the application compares the bridge output system designed accurately with the wheel rail force calculation method in the existing GB / T5599 specification. Mainly including the comparison of bridge output results under unit load and random load. This part analyzes the performance of the two methods under different working conditions, especially the accuracy, error range and measurement sensitivity of the bridge output.

[0126] In this embodiment, the bridge output results under unit load are compared:

[0127] The bridge output results of the application, the measured wheel rail force in the figure is calculated by formula (5), formula (13), formula (18) and formula (26), the strain unit is με, and the force unit is kN.

[0128] 1. According to the design of the application, the bridge output of vertical force and lateral force is optimized, which can provide more accurate measurement data. In the test design, unit vertical force Q=1kN and unit lateral force Y=1kN are applied respectively, and the eccentricity is 1mm. From the formula (5), it can be known that Figure 7 Figure 7 (a) of the (b) is the specification vertical force (continuous measurement), Figure 7 (c) of the (c) is the test lateral force, Figure 7 (d) of the (d) is the specification lateral force, and the bridge output results are as follows: Figure 7

[0129] Vertical force bridge output: when 1kN of unit vertical force is applied, the bridge output signal fluctuates little, and the absolute value of the signal output is close to a horizontal line, indicating that the method can accurately reflect the change of vertical force. Through correction formula calculation, the fluctuation amplitude of the bridge output signal is between-5% and 2.5%, which proves that the accuracy of the application in vertical force measurement is very high.

[0130] Lateral force bridge output: under the action of 1kN unit lateral force, the bridge output signal reflects the change of lateral force, and the absolute value of the signal output is also close to a horizontal line, and the fluctuation amplitude is between-2% and 1.2%. Although the output signal strength of the lateral force is relatively small, it still maintains high measurement accuracy.

[0131] 2. Bridge output results in GB / T5599 specification:

[0132] The bridge design in the specification is relatively simple, and the phase angle information of the wheel rail contact point is not considered in the calculation, so the output accuracy under unit load is lower than that of the application. By applying the same unit load, the bridge output results of the specification method are as follows:

[0133] ​​The bridge output signal of the vertical force fluctuates greatly when the standard method is applied to 1kN vertical force, and the fluctuation range is between-29% and 3.3%. Although the standard method can roughly reflect the change of the vertical force, the bridge signal has a large deviation due to the neglect of the phase angle information, and the measurement error is large, especially in the case of rapid change of the vertical force, the error is more obvious.

[0134] The bridge output signal of the lateral force and the fluctuation range are slightly larger than those of the present method.

[0135] The comparison summary under the unit load is as follows:

[0136] As can be seen from the test data, the bridge output of the present method under the unit load shows more stable and accurate results. The output signal error of the vertical force is only-5% to 2.5%, which is much lower than-29% to 3.3% of the standard method, and the error of the lateral force is controlled within-2% to 1.2%, which shows higher accuracy, but the output signal is weaker than the standard method. Considering the above, the vertical force adopts the bridge of the present test, and the lateral force adopts the standard bridge.

[0137] In this embodiment, the bridge output results under random load are compared as follows:

[0138] During the test, the load borne by the track wheel and the wheel is randomly changed. Therefore, the comparison of the bridge output results under random load is of great significance for evaluating the reliability and stability of the measurement method. Therefore, the bridge output results of the present method and GB / T5599 standard are compared.

[0139] 1. The bridge output results of the present method

[0140] Under the action of random load, the bridge output of the present method considers the phase angle information and separately corrects the vertical force and the lateral force. Therefore, the signal of the bridge output is more stable, and the error is smaller.

[0141] Random load without eccentric distance:

[0142] Under the action of random load without eccentric distance, it is assumed that the error standard deviation of the bridge output signal is 1με, and the test results are as shown in Figure 8 , in which, Figure 8 (a) of the figure is the vertical force of the present test, Figure 8 (b) of the figure is the standard vertical force (continuous measurement), Figure 8 (c) of the figure is the lateral force of the present test, Figure 8 (d) of the figure is the standard lateral force, the data shows that the bridge output signal of the present method remains high stability under random load, as shown in Figure 9 , in which, Figure 9 (a) of the figure is the vertical force of the present test,Figure 9 (b) is the normalized vertical force (continuous measurement), Figure 9 (c) is the test transverse force, Figure 9 (d) is the normalized transverse force. Due to the bridge design considering the strain gauge arrangement at different angles and the phase angle correction, the measurement error is controlled within -4% ~ 3% compared with the normalized method, especially when the random load changes frequently, the signal output is still accurate.

[0143] Random load with eccentricity:

[0144] As shown in Figure 10 , in the case of eccentricity (eccentricity is 7mm), the test shows that the eccentricity has little effect on the vertical force, and the bridge output still maintains high precision. The effect of eccentricity on transverse force is relatively large, about 3kN, but after the bridge correction, the error is still small, and the overall output result is stable.

[0145] 2、GB / T5599 specification bridge output results

[0146] Compared with the present application, the bridge design in the specification fails to effectively cope with the influence of random load and eccentricity, especially when the load changes rapidly, the error of signal output is large.

[0147] Under the action of random load with and without eccentricity, the output signal of the vertical force bridge of the normalized method fluctuates greatly, and the output signal of the transverse force bridge fluctuates less, which is close to the method of the present application, as shown in Figure 9 . Since the normalized method does not consider the phase angle correction, especially when the strain gauge arrangement is not reasonable, the accuracy of vertical force measurement is significantly reduced, resulting in large signal deviation.

[0148] 3、Comparison summary under random load

[0149] From the comparison results under the action of random load, it can be seen that the bridge output of the present application still maintains high precision and stability under the action of random load (without eccentricity and with eccentricity), and the error is controlled within a small range. In contrast, the normalized method of GB / T5599 specification has a large error in the output signal of the vertical force bridge under the same working condition, and the eccentricity has a significant effect on the transverse force. Therefore, the measurement accuracy of the present application is significantly better than that of the normalized method under complex working conditions.

[0150] The track wheel wheel rail force calculation method of the application, through the optimization of bridge path design and phase angle correction, shows more stable and accurate measurement results under the action of unit load and random load. Compared with the traditional method in GB / T5599 specification, the bridge path output of the application has lower error in vertical force measurement, especially under the condition of random load and eccentricity, it still maintains high precision. Therefore, the calculation method of the application has the advantage of high precision in the test measurement of wheel rail force, and can provide more reliable mechanical data.

[0151] The technical effect of the application mainly lies in the optimization of track wheel design, the calculation method based on phase angle and the improvement of bridge path structure, which significantly improves the precision, stability and reliability of wheel rail force measurement. The following is a specific effect description of the application, combined with the technical scheme for quantitative analysis:

[0152] 1. Improved measurement accuracy

[0153] The application optimizes the arrangement of strain gauges and bridge path design, solves the measurement error problem caused by unreasonable strain gauge position and ignoring phase angle information in traditional wheel rail force measurement method. Under the action of random load, the measurement result of the application is more accurate and stable. The random load with and without eccentricity is tested in the test.

[0154] Vertical force measurement accuracy: The strain gauges for vertical force are arranged at the inflection point, so that the bridge path can accurately reflect the change of vertical force. Compared with the traditional measurement method, the application effectively reduces the random error through strain gauge optimization and phase angle correction. The test shows that under the action of random load, the measurement error of vertical force is reduced to-4%~3%, compared with-40% to-50% of the traditional method in GB / T5599 specification, the error is greatly reduced, which shows that the application can still maintain high precision measurement under the action of random load.

[0155] Lateral force measurement accuracy: The lateral force strain gauges are arranged at the end of the wheel rim plate, which can maximize the capture of lateral force strain signals and reduce the interference of vertical force. At the same time, under the condition of eccentricity, although the fluctuation of lateral force increases slightly, after phase angle correction, the measurement error of lateral force of the application is controlled within 5%. This precision improvement is particularly important in complex working conditions, ensuring continuous measurement and high precision calculation of wheel rail force in the test process, and providing high precision wheel rail force data under different working conditions.

[0156] 2. Simplify the test process and reduce the time cost

[0157] The traditional wheel rail force measurement method needs to install multiple strain gauges on the axle or rim, and needs to be calibrated and debugged repeatedly, which not only increases the complexity of the test process, but also increases the time cost.

[0158] Test procedure simplification: The present application simplifies the installation process of strain gauges by designing a rail wheel force measuring device. In the traditional method, the installation of strain gauges needs to be repeated for different vehicle types. However, the rail wheel device of the present application can complete the installation and debugging of strain gauges at one time without repeated debugging for different vehicle types. The test preparation time is reduced by more than 40%.

[0159] Debugging time is shortened: Due to the optimization of bridge structure and the reasonable layout of strain gauges, the calibration work in the test process is reduced, and the total test time is reduced by about 30%. This simplification significantly reduces the preparation and execution time of large-scale tests, improving the test efficiency.

[0160] 3. Improvement of measurement sensitivity

[0161] The present application significantly improves the sensitivity of the measurement system by optimizing the design of the spoke plate opening. Especially, the strain output of the vertical force is significantly amplified.

[0162] Optimization effect of the opening scheme: Tests have shown that by optimizing the traditional solid structure of the spoke plate to a fan-shaped opening design, the strain signal under the action of vertical force is increased by about 2.5 times. Before the opening, the radial strain under the action of vertical force Q=10kN is only 3.1με, while after the fan-shaped opening, the radial strain is increased to 7.7με. This shows that the present application can significantly amplify the strain signal and improve the measurement sensitivity through the opening design.

[0163] Strength and sensitivity balance after optimization of fan-shaped opening: Under the premise of maintaining structural strength, the optimized fan-shaped opening design can effectively reduce the stress concentration phenomenon under the action of lateral force. Compared with the circular opening, the maximum radial strain of the fan-shaped opening is increased by about 10%, while the maximum stress is reduced to 15MPa, which is lower than the safety limit (18MPa), ensuring the structural safety under complex loads.

[0164] 4. Enhanced anti-interference ability and stability

[0165] Because the traditional measurement method does not consider the phase angle change of the wheel-rail contact point, the measurement process is easily affected by external interference, especially when the wheel is running at high speed during the test, the stability of the measurement signal is poor. The present application significantly improves the anti-interference ability by introducing the phase angle correction technology.

[0166] Effect of phase angle correction: Under different working conditions, especially at high speed and under random load, the present application can reduce the fluctuation of strain signal through the phase angle correction algorithm. Tests show that the signal fluctuation amplitude of the traditional method under random load reaches -40% to -50%, while the fluctuation amplitude is reduced to -4% ~ 3% after phase angle correction of the present application, indicating that it has better anti-interference ability under complex working conditions.

[0167] The measurement signal is stable: under complex load, the vertical force and lateral force measurement signals are more stable. The test results show that the signal fluctuation range of the lateral force is only 5%, indicating that the application can provide more reliable and consistent measurement data.

[0168] 5. Reduced equipment service life and maintenance cost

[0169] The traditional wheel-rail force measurement method relies on a large number of strain gauges installed on dynamic components such as axles and rims, which are easily affected by wear, vibration and external environment, resulting in high equipment maintenance cost and short service life.

[0170] Optimization of strain gauge arrangement: the application arranges strain gauges on the track wheel device instead of directly installing them on the wheel and axle, avoiding damage to the strain gauges caused by high-speed motion. The fixing device of the track wheel can maintain the stability of the device during measurement, reducing the wear of the measuring device caused by dynamic changes of the vehicle.

[0171] Reduced maintenance frequency: due to the reasonable arrangement of strain gauges and the small dynamic load of the device, the wear of the device is reduced, the service life of the device is prolonged, and the maintenance frequency is reduced by more than 30%. At the same time, the equipment maintenance cost is reduced by about 25%.

[0172] In summary, the application optimizes the track wheel force measuring device, bridge design, phase angle correction and strain gauge arrangement, significantly improves the accuracy, sensitivity and stability of wheel-rail force measurement, and provides significant improvement in test process, maintenance cost, equipment service life, etc. Combined with the above quantitative data, it can be seen that compared with the traditional method, the measurement error of the application is significantly reduced, the test process is simplified by 40%, and the maintenance cost is reduced by 25%. These effects fully demonstrate the significant advantages of the application in the field of wheel-rail force measurement.

[0173] In summary, the highlights of the application are as follows:

[0174] 1. High-precision wheel-rail force measurement. By attaching strain gauges to the track wheel device and combining phase angle calculation technology, the application can accurately measure the vertical force and lateral force at the wheel-rail contact point, especially under complex conditions such as random load and eccentricity, providing stable and reliable data output.

[0175] 2. Application of phase angle information. Unlike traditional methods without phase angle calculation, the application introduces phase angle information during measurement, making the measured wheel-rail force more accurately reflect the actual situation at the wheel-rail contact point, reducing errors in the signal transmission process and improving measurement accuracy.

[0176] 3、Test procedure simplification. The traditional wheel-rail force measurement method requires the installation of strain gauges at key locations such as axles and wheel rims. Different vehicle models require repeated installation and debugging. The track wheel device of the present application simplifies this process, allowing continuous measurement with only one-time installation of the track wheel equipment, greatly reducing test preparation time.

[0177] 4、Sensitivity improvement. Compared to traditional web-type wheels, the track wheel equipment of the present application optimizes the arrangement of strain gauges and the design of the spoke plates, making it more sensitive to external excitation strain response, providing greater strain output under vertical and lateral forces, and improving measurement accuracy.

[0178] The present application improves and optimizes many technical defects in the existing wheel-rail force measurement method through innovative design and technical means, effectively solving the following problems in the current wheel-rail force measurement method:

[0179] 1、Test procedure is complicated. The commonly used wheel-rail force measurement method requires the installation of multiple strain gauges at the axles, wheel rims or other key positions, which not only requires test personnel to have high technical ability, but also increases the complexity and time consumption of test preparation. Especially in different vehicle models or different test environments, strain gauges need to be reinstalled and calibrated before each test, significantly increasing the cost and time investment of the test.

[0180] The present application avoids the complex process of repeatedly installing strain gauges on different vehicle models by designing a track wheel force measurement device. The track wheel equipment can be installed on the track once, and the wheel-rail force can be measured continuously by presetting the strain gauge position, thereby simplifying the test procedure, reducing installation time and equipment debugging workload, and improving test efficiency.

[0181] 2、Ignoring phase angle information. The existing measurement method ignores the phase angle change of the wheel-rail contact point during rotation, relying only on strain gauge measurement of amplitude signals to calculate wheel-rail force. This method is prone to errors in dynamic situations, especially at high speeds. Wheel-rail force as a dynamic quantity constantly changes in direction and size during wheel rotation. If the phase angle information is ignored, the measured wheel-rail force cannot accurately reflect the actual mechanical properties, resulting in distorted measurement results.

[0182] The present application uses a phase angle-based calculation method, which includes the phase angle change of the wheel-rail contact point in the calculation process, and can more accurately reflect the dynamic changes of the wheel-rail force. By introducing phase angle information, the present application can better capture the direction change of the wheel-rail force, greatly improving the accuracy of the measurement, especially in complex conditions such as random loads in tests, this improvement significantly reduces errors.

[0183] 3. Low measurement sensitivity. In the prior art, the web-type wheel design used in wheel-rail force measurement methods, although having certain weight reduction and load bearing advantages in structure, can cause small strain signals in the stress transmission process, thereby affecting the measurement accuracy. In addition, the structural characteristics of the web-type wheel also limit its measurement sensitivity under the action of wheel-rail force.

[0184] The present application optimizes the track wheel device, especially improves the opening shape of the wheel web and the arrangement position of the strain gauge, so that the device shows high sensitivity under the action of vertical force and lateral force. Tests show that the design of fan-shaped opening greatly increases the strain signal output, and can capture greater strain changes under the action of various forces, making the measurement results more accurate and stable, meeting the high requirements for sensitivity in wheel-rail force measurement.

[0185] 4. Insufficient measurement accuracy. Existing measurement methods usually ignore the mechanical complexity in the dynamic process of wheel-rail force, especially in the measurement accuracy of forces in different directions. The traditional wheel-rail force measurement method is relatively accurate in measuring lateral force, but in the measurement of vertical force, it is often difficult to accurately reflect the actual stress condition during wheel-rail contact due to low sensitivity. In addition, due to the deviation of the force transmission path of the system measurement device in different directions, the calculation results may differ greatly from the actual values.

[0186] The present application not only improves the sensitivity of the strain gauge, but also significantly improves the calculation accuracy of the wheel-rail force through the phase angle calculation method, especially in the measurement of vertical force. Through continuous measurement and calculation of forces in different directions, the present application can better reflect the actual changes of wheel-rail force during vehicle operation, significantly improve the accuracy of mechanical data, and reduce errors caused by device structure problems.

[0187] 5. Difficult to maintain and easy to damage the traditional wheel-rail force measurement method. The strain gauge is usually directly installed on the axle or rim, etc. During the test process, it is long-term in high-speed motion and high-pressure environment, and is easily affected by external factors such as vibration, impact and wear, resulting in shorter service life of the equipment and higher maintenance cost. The damage of the strain gauge not only affects the accuracy of the measurement, but also causes the interruption of the test or the loss of data.

[0188] The track wheel force measuring device of the present application is designed on the track wheel instead of the wheel itself, avoiding the influence of the high-speed motion of the axle and the wheel on the measuring device. By arranging the strain gauge in the track wheel device, the risk of damage to the equipment is reduced, and the durability and reliability of the device are improved. In addition, the equipment of the present application is easy to install, which is convenient for subsequent maintenance and updating, greatly reducing the maintenance cost of the equipment and the risk of interruption of the test.

[0189] 6、Data processing lag, continuous measurement difficult. The current wheel-rail force measurement system has limited efficiency in data acquisition and processing, especially when the wheel is running at high speed. Due to the large amount of data and rapid changes, the traditional measurement system is difficult to achieve continuous measurement of wheel-rail force, and may have problems such as data lag and distortion, which affect the test results.

[0190] The present application can realize real-time and continuous measurement of wheel-rail force by simplifying the data acquisition process and optimizing the solving algorithm. Especially during the high-speed running of the track wheel, the force measuring device of the present application can quickly respond to the mechanical changes of the wheel and the track, ensuring the real-time and accuracy of the data, and meeting the continuous force measurement and solving requirements of the wheel-rail force in the test.

Claims

1. A method for continuous force measurement and calculation of a spoked track wheel, characterized in that, This continuous force measurement and calculation method for spoked track wheels is applied to track wheel force measuring devices and includes the following steps: Multiple strain gauges, connected to form a bridge circuit, are evenly arranged on a spoked track wheel, specifically as follows: Vertical force measurement bridge circuit: Multiple strain gauges are arranged at the inflection point of the spoke plate to obtain the strain change under the action of vertical force. The strain gauges are connected by a full bridge circuit. Lateral force measurement bridge circuit: Multiple strain gauges are arranged at the ends of the spokes and at the straight section to eliminate the interference of vertical force on the lateral force measurement. The expression for the experimentally measured vertical force is as follows: in, This represents the vertical force measured in the experiment. and Indicates the actual vertical force The output signal of the drooping force bridge circuit under action. This represents the output signal of the bridge circuit when a unit vertical force is applied. This indicates the output signal of the vertical force bridge circuit after correcting the phase angle. Indicates the rotation angle of the track wheel. , , , , and All represent the strain distribution at measuring points arranged at an angle on the track wheel under a unit vertical force; By using the bridge output signal, the strain distribution under a unit vertical force is calculated, and the actual vertical force under external force is obtained. By superimposing and correcting the bridge output signal, the lateral force is obtained, and continuous force measurement and calculation of the spoked track wheel is completed. The expression for lateral force is as follows: in, This represents the transverse force measured in the experiment. and Both represent the output signal of the bridge circuit under a unit lateral force. and This indicates the bridge circuit output signal under external load. This represents the actual lateral force. Indicates the eccentricity of the point of application of the vertical force. and Both represent the output signals of the bridge circuit under unit vertical force and eccentricity. and Both represent the strain distribution on the inner and outer surfaces under unit vertical force and eccentricity. and Both represent the strain distribution on the inner and outer surfaces under a unit transverse force.

2. The method for continuous force measurement and calculation of spoked track wheels according to claim 1, characterized in that, The track wheel force measuring device includes a track wheel and strain gauges; The track wheel is mounted between the wheel axle and the bearing housing via a bearing, and the strain gauge is disposed on the track wheel.

3. The method for continuous force measurement and calculation of spoked track wheels according to claim 2, characterized in that, The spoke plate of the track wheel adopts a semi-spoke design and has openings. The strain gauges are arranged at the inflection points of the spokes; the strain gauges are also arranged at the ends of the spokes and at the straight sections.

4. The method for continuous force measurement and calculation of spoked track wheels according to claim 3, characterized in that, The openings on the spokes are fan-shaped.

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