Trailer towing test device and method

Abstract

The application discloses a trailer traction test device and method, relates to the technical field of trailer traction test, and aims to solve the technical problem that the prior art is inconvenient for comprehensively detecting the mechanical property of a traction pin under complex working conditions, and comprises the following steps: S1, a preparation stage, removing an original traction saddle of a traction vehicle to be tested, replacing the traction saddle with a test saddle, arranging a mechanical sensor on the inner hole wall of the test saddle and the inner wall of a lock tongue in the axial direction, and connecting the test saddle of the traction vehicle with a traction pin of a trailer; S2, test working condition setting, setting uniform forward movement and uniform reverse movement working conditions; S3, uniform traction working condition test, starting the traction vehicle and driving the traction vehicle according to the set uniform forward movement working condition, detecting the pressure of the rear side surface of the traction pin by using the mechanical sensor arranged on the inner wall of the lock tongue, and adjusting the driving angle by a driver of the traction vehicle according to the driving path, so that the relative position of the traction pin and the mechanical sensor covers each detection area. The application has the advantages of evaluating the mechanical property of the traction pin under complex working conditions.

Description

Technical Field

[0001] This invention relates to the field of trailer traction testing technology, and more specifically, to a trailer traction testing device and method. Background Technology

[0002] In the field of trailer traction performance testing, existing technologies typically employ simple tensile testing equipment to test the basic mechanical properties of the components connecting the trailer and the tractor. This traditional testing method generally involves applying tensile force through a mechanical device under specific static conditions, measuring the load-bearing capacity of components such as the tow pin in a single direction of force, and thus assessing whether it meets basic usage requirements. For example, some testing equipment can only fix the position of the tow pin, apply a stable tensile force to the tractor, observe the deformation of the tow pin, or measure the maximum tensile force it can withstand.

[0003] However, this traditional testing technology has obvious shortcomings: it cannot comprehensively test the mechanical properties of the towing pin under actual complex working conditions, especially the changes in the force on the surface of the towing pin caused by changes in angle, speed and different driving directions during the operation of the tractor. It is difficult to accurately detect potential dents and damage on the surface of the towing pin, and it is also impossible to scientifically quantify and evaluate the safety level of the towing pin. This is extremely detrimental to ensuring the safety of the connection between the trailer and the tractor.

[0004] In view of this, we propose a trailer traction test device and method. Summary of the Invention

[0005] The purpose of this invention is to provide a trailer traction testing device and method to solve the technical problem that the existing technology is not convenient for comprehensively testing the mechanical properties of the traction pin under complex working conditions.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a trailer towing test method, comprising the following steps:

[0007] S1. Preparation stage: Remove the original towing saddle of the tractor to be tested, replace it with a test saddle, and arrange mechanical sensors along the axial direction on the inner wall of the test saddle and the inner wall of the locking tongue. Connect the tractor test saddle to the trailer towing pin.

[0008] S2. Test condition settings: Set constant speed forward and constant speed reverse conditions;

[0009] S3. Constant speed traction condition test: The tractor starts and travels at a set constant speed. The mechanical sensors arranged on the inner wall of the locking tongue are used to detect the pressure on the rear surface of the traction pin. The tractor driver adjusts the driving angle according to the driving path so that the relative position of the traction pin and the mechanical sensor covers each detection area.

[0010] S4. Constant speed reversing condition test: The tractor starts and drives according to the set constant speed reversing condition. The pressure of the front surface of the traction pin is detected by the mechanical sensor arranged on the inner wall of the test saddle. The tractor driver adjusts the driving angle according to the driving path so that the relative position of the traction pin and the mechanical sensor covers each detection area.

[0011] S5. Data analysis: Obtain the pressure data collected in steps S3 and S4, filter the collected data, and identify surface dents and damage to the traction pin.

[0012] S6. Safety assessment: quantify damage characteristics and evaluate the safety level of the traction pin.

[0013] Preferably, in step S1, the mechanical sensor group on the inner wall of the test saddle and the inner wall of the lock tongue is arranged opposite to each other;

[0014] When connecting the trailer and the tractor, use a gap measuring ruler with an accuracy of 0.1mm to check the gap at the connection point and ensure the gap value is correct. Within the standard range .

[0015] Preferably, in steps S3 and S4, the tractor driver adjusts the driving angle according to the driving path. Must meet ,in, This represents the maximum angle at which the tractor swings to the left. To determine the maximum angle at which the tractor swings to the right, the driver slowly turns the steering wheel to make the tractor's trajectory change in a slight arc, altering the relative position of the traction pin and the force sensor. This ensures that each detection area on the traction pin surface, divided along the axial direction, is scanned by the force sensor at least once.

[0016] Preferably, in step S5, the data filtering process employs a wavelet transform algorithm, and its transform formula is as follows:

[0017] ;

[0018] in, It is the original pressure signal. It is a scale parameter. These are translation parameters. These are wavelet basis functions;

[0019] Discrete wavelet transform is a discretization of continuous wavelet transform in terms of scale and translation. For discrete sequences... Its discrete wavelet transform is expressed as:

[0020] ;

[0021] in, , is the discretized wavelet basis function. It is a normalization factor. For discrete time sequence numbers. The length of the sequence. This is a discrete index for the scale factor. The discrete index of the translation factor is used to determine the position of the wavelet function on the discrete time axis.

[0022] Preferably, in step S5, the specific method for identifying dent damage on the traction pin surface is as follows: the location and number of dent damage are determined by a preset pressure data missing identification algorithm based on threshold comparison, and the pressure data threshold is used. ,in, This value is obtained by statistically averaging the pressure data collected from the traction pin under normal conditions and the same test conditions. It represents the average level of the traction pin surface pressure under normal conditions. The standard deviation of the pressure data is represented by... This represents a coefficient determined based on the false positive rate requirement and the reliability requirement of the test;

[0023] When the processed pressure data satisfy At that time, it was determined that there was a dent or damage at that location.

[0024] Preferably, in step S6, the method for quantifying damage characteristics is as follows:

[0025] Calculate damage density , , ,in, This indicates the number of dents or damage on the outer surface of the traction pin. This indicates the outer surface area of ​​the traction pin. This indicates the radius of the base of the traction pin. Indicates the length of the traction pin;

[0026] The method for assessing the safety level of traction pins is as follows:

[0027] The safety level is assessed based on a neural network model. The model employs a multilayer perceptron structure. The input layer receives damage feature data obtained from data analysis, including the location, number, and density of dent damage. The model outputs the safety level. ,in, This represents the activation function. The weights are represented and updated using the backpropagation algorithm. , indicating the amount of weight update. Represents the first input layer The input value of each neuron. Indicates the bias term. Indicates the learning rate. This represents the loss function calculated using the cross-entropy loss function. , Indicates the true label, This represents the model's predicted value. The model is trained using a large amount of traction pin data with known safety conditions and damage characteristics to improve its accuracy and reliability.

[0028] Preferably, in step S6, a security level determination criterion is set: a security level score is assigned. The security level output by the model Through linear transformation function To obtain, that is , ,in, and These are the fitting coefficients, used to output the safety level of the model based on these samples. and the corresponding actual security level score Linear regression analysis was performed to minimize the error between the actual score and the transformed score to determine and The value;

[0029] when At that time, it was determined that the traction pin was in a safe condition;

[0030] when At that time, it was determined that the traction pin was in an unsafe condition;

[0031] in, The safety level score threshold is determined in advance through a large amount of experimental data and industry standards.

[0032] A trailer traction testing device includes a test saddle, the interior of which has an inner wall, a detachable traction pin is disposed inside the inner wall, and a locking tongue for locking and limiting the traction pin is movably disposed inside the test saddle.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. This invention, by designing mechanical sensors arranged along the axial direction on the inner wall of the test saddle and the inner wall of the locking tongue, and setting constant speed forward and constant speed reverse conditions for testing, can comprehensively detect the surface pressure changes of the traction pin under different working conditions during actual driving, accurately identify the surface dent damage of the traction pin, and effectively solve the problem that the existing technology cannot comprehensively detect the mechanical properties of the traction pin under complex working conditions.

[0035] 2. This invention uses wavelet transform algorithm to filter the collected data, removing noise caused by factors such as vehicle vibration and electromagnetic interference, making the detection data more accurate and reliable, and further improving the accuracy of identifying surface dent damage of the traction pin, thereby more accurately evaluating the mechanical performance of the traction pin under complex working conditions.

[0036] 3. This invention evaluates the safety level of the towing pin based on a neural network model and sets reasonable safety level judgment criteria. By quantifying damage characteristics, it can scientifically quantify and assess the safety status of the towing pin. Compared with existing technologies, it provides a more reliable guarantee for the safety of the connection between the trailer and the tractor, and further ensures the safe use of the towing pin under complex working conditions. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0038] Figure 2 This is a schematic diagram of the structure of the traction saddle and traction pin in the engagement state of the present invention.

[0039] Explanation of the labels in the diagram:

[0040] 1. Test saddle; 2. Inner bore wall; 3. Traction pin; 4. Locking tongue. Detailed Implementation

[0041] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with the accompanying drawings.

[0042] Example 1, such as Figure 1 As shown, the present invention provides a trailer towing test method, comprising the following steps:

[0043] S1. Preparation stage: Remove the original towing saddle of the tractor to be tested, replace it with a test saddle, and arrange mechanical sensors along the axial direction on the inner wall of the test saddle and the inner wall of the locking tongue. Connect the tractor test saddle to the trailer towing pin.

[0044] S2. Test condition setting: Based on actual usage scenarios and industry standards, set constant speed forward and constant speed reverse conditions, determine the speed range, and ensure that the deviation between the actual speed and the set speed is within the allowable range through the speed closed-loop control system.

[0045] S3. Constant speed traction condition test: The tractor starts and travels at a set constant speed. The mechanical sensors arranged on the inner wall of the locking tongue are used to detect the pressure on the rear surface of the traction pin. The tractor driver adjusts the driving angle according to the driving path so that the relative position of the traction pin and the mechanical sensor covers each detection area.

[0046] S4. Constant speed reversing condition test: The tractor starts and drives according to the set constant speed reversing condition. The pressure of the front surface of the traction pin is detected by the mechanical sensor arranged on the inner wall of the test saddle. The tractor driver adjusts the driving angle according to the driving path so that the relative position of the traction pin and the mechanical sensor covers each detection area.

[0047] S5. Data analysis: Obtain the pressure data collected in steps S3 and S4, filter the collected data, and identify surface dents and damage to the traction pin.

[0048] S6. Safety assessment: quantify damage characteristics and evaluate the safety level of the traction pin.

[0049] In an embodiment of the present invention, in S1, the mechanical sensor group on the inner wall of the test saddle and the inner wall of the lock tongue is arranged opposite to each other;

[0050] When connecting the trailer and the tractor, use a gap measuring ruler with an accuracy of 0.1mm to check the gap at the connection point and ensure the gap value is correct. Within the standard range The scope of this standard is determined by the design specifications for the connection between trailers and tractors;

[0051] The output torque of the tractor engine was measured using an engine comprehensive performance testing instrument. and rotational speed Using the power formula of a power system Calculate the power of the power system to ensure ,in, Determined based on the minimum power requirements needed for testing and the power demands of the vehicle when fully loaded;

[0052] Input power is measured by installing torque and speed sensors on the input and output shafts of the transmission system. and output power Using the efficiency formula of the transmission system Calculate the efficiency of the transmission system to ensure ,in, The efficiency value is determined based on industry standard values ​​for similar transmission systems to ensure the vehicle can operate normally.

[0053] In embodiments of the present invention, in S3 and S4, the tractor driver adjusts the driving angle according to the driving path. Must meet ,in, This represents the maximum angle at which the tractor swings to the left. To determine the maximum angle at which the tractor swings to the right, the driver slowly turns the steering wheel to make the tractor's trajectory change in a slight arc, altering the relative position of the traction pin and the force sensor. This ensures that each detection area on the traction pin surface, divided along the axial direction, is scanned by the force sensor at least once.

[0054] In an embodiment of the present invention, in step S5, the data filtering method employs a wavelet transform algorithm, and its transform formula is as follows:

[0055] ;

[0056] in, It is the raw pressure signal, that is, the signal of the unprocessed change in pressure on the surface of the traction pin over time, collected by the mechanical sensor. This is the scaling parameter, used to control the scaling of the wavelet function. Different scales correspond to different frequency components; larger scales correspond to low-frequency components, and smaller scales correspond to high-frequency components. This is the translation parameter, used to control the translation of the wavelet function on the time axis. Changing the value of b allows the wavelet function to analyze the signal at different time positions. These are wavelet basis functions, which are functions with finite duration and oscillatory properties. This indicates its complex conjugate form;

[0057] Discrete wavelet transform is a discretization of continuous wavelet transform in terms of scale and translation. For discrete sequences... Its discrete wavelet transform is expressed as:

[0058] ;

[0059] in, , is the discretized wavelet basis function. It is a normalization factor. For discrete time sequence numbers. The length of the sequence. This serves as a discrete index for the scale factor, corresponding to different scale levels and reflecting the different frequency resolutions of the signal. The discrete index of the translation factor is used to determine the position of the wavelet function on the discrete time axis. First, an appropriate wavelet basis function and decomposition level are selected to perform wavelet decomposition on the original pressure data, decomposing the data into sub-signals of different scales and frequencies. By setting a threshold, the wavelet coefficients are thresholded to remove the wavelet coefficients corresponding to noise generated by vehicle vibration and electromagnetic interference. Finally, the processed wavelet coefficients are reconstructed by wavelet to obtain the filtered pressure data.

[0060] The specific method for identifying dent damage on the surface of the traction pin is as follows: The location and number of dent damages are determined using a preset pressure data missing identification algorithm based on threshold comparison, and the pressure data threshold is used. ,in, This value is obtained by statistically averaging the pressure data collected from the traction pin under normal conditions and the same test conditions. It represents the average level of the traction pin surface pressure under normal conditions. The standard deviation of pressure data reflects the degree of dispersion of the pressure data relative to the mean. This represents a coefficient determined based on the false positive rate requirement and the reliability requirement of the test, and is generally determined through multiple simulation experiments and actual tests.

[0061] When the processed pressure data satisfy At that time, it was determined that there was a dent or damage at that location.

[0062] In an embodiment of the present invention, in S6, the method for quantifying damage characteristics is as follows:

[0063] Calculate damage density , , ,in, This indicates the number of dents or damage on the outer surface of the traction pin. This indicates the outer surface area of ​​the traction pin. This indicates the radius of the base of the traction pin. The length of the traction pin is indicated. The surface of the traction pin is divided into grids, and the number of dents and damages in each grid area is counted. Thus, the damage density can be calculated;

[0064] The method for assessing the safety level of traction pins is as follows:

[0065] The safety level is assessed based on a neural network model. The model employs a multilayer perceptron structure. The input layer receives damage feature data obtained from data analysis, including the location, number, and density of dent damage. The model outputs the safety level. ,in, This represents the activation function, used to introduce nonlinear factors and enhance the expressive power of the model. The weights are represented and updated using the backpropagation algorithm. , indicating the amount of weight update. Represents the first input layer The input value of each neuron, i.e., a certain dimension of the damage feature data. This represents the bias term, used to adjust the activation threshold of neurons. The learning rate is determined based on the convergence speed and stability requirements of the model training, and controls the step size of each weight update. This represents the loss function calculated using the cross-entropy loss function. It is used to measure the difference between the model's predicted values ​​and the true labels. This indicates the actual label, that is, the safety level corresponding to the tow pin with a known safety status. This represents the model's predicted value. The model is trained using a large amount of known safety status and damage characteristics of traction pins to improve its accuracy and reliability.

[0066] Set safety level assessment criteria: assign a safety level score. The security level output by the model Through linear transformation function To obtain, that is , ,in, and These are the fitting coefficients, obtained through statistical analysis of a large number of traction pin samples with known safety levels. The safety level is then output using a model based on these samples. and the corresponding actual security level score Linear regression analysis was performed to minimize the error between the actual score and the transformed score to determine and The value;

[0067] when At that time, it was determined that the traction pin was in a safe condition;

[0068] when At that time, it was determined that the traction pin was in an unsafe condition;

[0069] in, The safety level score threshold is determined in advance through a large amount of experimental data and industry standards.

[0070] Example 2, as follows Figure 2 As shown, a trailer traction test device includes a test saddle 1, an inner wall 2 formed inside the test saddle 1, a detachable traction pin 3 inside the inner wall 2, and a locking tongue 4 movably disposed inside the test saddle 1 for locking and limiting the traction pin 3.

[0071] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. A trailer traction test method, characterized in that, Includes the following steps: S1. Preparation stage: Remove the original towing saddle of the tractor to be tested, replace it with a test saddle, and arrange mechanical sensors along the axial direction on the inner wall of the test saddle and the inner wall of the locking tongue. Connect the tractor test saddle to the trailer towing pin. S2. Test condition settings: Set constant speed forward and constant speed reverse conditions; S3. Constant speed traction condition test: The tractor starts and travels at a set constant speed. The mechanical sensors arranged on the inner wall of the locking tongue are used to detect the pressure on the rear surface of the traction pin. The tractor driver adjusts the driving angle according to the driving path so that the relative position of the traction pin and the mechanical sensor covers each detection area. S4. Constant speed reversing condition test: The tractor starts and drives according to the set constant speed reversing condition. The pressure of the front surface of the traction pin is detected by the mechanical sensor arranged on the inner wall of the test saddle. The tractor driver adjusts the driving angle according to the driving path so that the relative position of the traction pin and the mechanical sensor covers each detection area. S5. Data analysis: Obtain the pressure data collected in steps S3 and S4, filter the collected data, and identify surface dents and damage to the traction pin. S6. Safety assessment: quantify damage characteristics and evaluate the safety level of the traction pin.

2. The trailer traction test method according to claim 1, characterized in that, In S1, the mechanical sensor group on the inner wall of the test saddle seat and the inner wall of the lock tongue are arranged opposite to each other. When connecting the trailer and the tractor, use a gap measuring ruler with an accuracy of 0.1mm to check the gap at the connection point and ensure the gap value is correct. Within the standard range .

3. The trailer traction test method according to claim 2, characterized in that, In S3 and S4, the tractor driver adjusts the driving angle according to the driving path. Must meet ,in, This represents the maximum angle at which the tractor swings to the left. To determine the maximum angle at which the tractor swings to the right, the driver slowly turns the steering wheel to make the tractor's trajectory change in a slight arc, altering the relative position of the traction pin and the force sensor. This ensures that each detection area on the traction pin surface, divided along the axial direction, is scanned by the force sensor at least once.

4. The trailer traction test method according to claim 3, characterized in that, In step S5, the data filtering process employs a wavelet transform algorithm, and its transform formula is as follows: ； in, It is the original pressure signal. It is a scale parameter. These are translation parameters. These are wavelet basis functions; Discrete wavelet transform is a discretization of continuous wavelet transform in terms of scale and translation. For discrete sequences... Its discrete wavelet transform is expressed as: ； in, , is the discretized wavelet basis function. It is a normalization factor. For discrete time sequence numbers. The length of the sequence. This is a discrete index for the scale factor. The discrete index of the translation factor is used to determine the position of the wavelet function on the discrete time axis.

5. The trailer traction test method according to claim 4, characterized in that, In step S5, the specific method for identifying dent damage on the traction pin surface is as follows: the location and number of dent damage are determined by a preset pressure data missing identification algorithm based on threshold comparison, and the pressure data threshold is used. ,in, This value is obtained by statistically averaging the pressure data collected from the traction pin under normal conditions and the same test conditions. It represents the average level of the traction pin surface pressure under normal conditions. The standard deviation of the pressure data is represented by... This represents a coefficient determined based on the false positive rate requirement and the reliability requirement of the test; When the processed pressure data satisfy At that time, it was determined that there was a dent or damage at that location.

6. The trailer traction test method according to claim 5, characterized in that, In S6, the method for quantifying damage characteristics is as follows: Calculate damage density , , ,in, This indicates the number of dents or damage on the outer surface of the traction pin. This indicates the outer surface area of ​​the traction pin. This indicates the radius of the base of the traction pin. Indicates the length of the traction pin; The method for assessing the safety level of traction pins is as follows: The safety level is assessed based on a neural network model. The model employs a multilayer perceptron structure. The input layer receives damage feature data obtained from data analysis, including the location, number, and density of dent damage. The model outputs the safety level. ,in, This represents the activation function. The weights are represented and updated using the backpropagation algorithm. , indicating the amount of weight update. Represents the first input layer The input value of each neuron. Indicates the bias term. Indicates the learning rate. This represents the loss function calculated using the cross-entropy loss function. , Indicates the true label, This represents the model's predicted value. The model is trained using a large amount of known safety status and damage characteristics of traction pins to improve its accuracy and reliability.

7. The trailer traction test method according to claim 6, characterized in that, In step S6, a security level determination criterion is set: a security level score is defined. The security level output by the model Through linear transformation function To obtain, that is , ,in, and These are the fitting coefficients, used to output the safety level of the model based on these samples. and the corresponding actual security level score Linear regression analysis was performed to minimize the error between the actual score and the transformed score to determine and The value; when At that time, it was determined that the traction pin was in a safe condition; when At that time, it was determined that the traction pin was in an unsafe condition; in, The safety level score threshold is determined in advance through a large amount of experimental data and industry standards.

8. An apparatus for use in a trailer traction test method as described in claim 7, characterized in that, The test saddle includes an inner wall with a detachable traction pin inside the inner wall, and a locking tongue for locking and limiting the traction pin is movably provided inside the test saddle.

Images