A system and method for evaluating the ride quality of a mining dump truck

Abstract

The application discloses a kind of mine dump truck's smoothness evaluation system and method, comprising: data acquisition module, the data acquisition module includes several triaxial accelerometer, displacement sensor, respectively for collecting vibration acceleration data and displacement data;Data analysis module, the data analysis module is used to receive vibration acceleration data and displacement data, and analysis obtains smoothness comprehensive evaluation value and seat comfort matrix.The present application evaluates the smoothness of mine dump truck by smoothness comprehensive evaluation value and seat comfort matrix, improves the problem that existing smoothness method evaluation is inaccurate caused by road condition, speed, seat low-frequency large-scale movement etc., improves the accuracy and transverse comparability of smoothness evaluation result.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of mine dump truck's smoothness evaluation system and method, belong to mine dump truck field. BACKGROUND

[0002] Automobile smoothness is an important index to evaluate the comfort of passengers during vehicle driving, in order to objectively and accurately evaluate the smoothness of the vehicle, "GB / T 4970-2009 Automobile Smoothness Test Method" specifies the smoothness test method and evaluation method of automobile under pulse input driving and random input driving condition. In order to ensure the accuracy of the evaluation method, the road, vehicle speed and other requirements are made in detail in the test method.

[0003] As a non-road vehicle, mine dump truck drives on low-grade road surface, and the normal driving speed is usually lower than 30-40km / h. The driver works for a long time, and the evaluation result obtained by using "GB / T 4970-2009 Automobile Smoothness Test Method" is basically very uncomfortable, which is greatly different from the subjective feeling of the driver, and cannot truly reflect the smoothness of the vehicle. The unevenness of the real test road is greatly different, which cannot be compared and evaluated laterally, and "GB / T 4970-2009 Automobile Smoothness Test Method" ignores the discomfort caused by large displacement of low-frequency suspension seat to the driver. SUMMARY

[0004] In view of the problems existing in the prior art, the present application provides a kind of mine dump truck's smoothness evaluation system and method.

[0005] In order to achieve the above purpose, a kind of mine dump truck's smoothness evaluation system provided by the present application comprises:

[0006] The data acquisition module comprises a plurality of three-axis accelerometers and displacement sensors, respectively used for collecting vibration acceleration data and displacement data;

[0007] The data analysis module is used for receiving vibration acceleration data and displacement data, and analyzing to obtain smoothness comprehensive evaluation value and seat comfort matrix.

[0008] As an improvement, the data acquisition module comprises three three-axis accelerometers and three displacement sensors; the three three-axis accelerometers are respectively installed on the footrest of the cab, the seat cushion and the seat backrest; the three displacement sensors are respectively installed on the left front suspension oil cylinder, the right front suspension oil cylinder and the seat under the cab, respectively used for measuring the extension amount of the left front suspension oil cylinder, the extension amount of the right front suspension oil cylinder and the vertical movement amount of the cab seat.

[0009] As an improvement, the displacement sensors installed on the left front and right front suspension oil cylinders are calibrated to make the sensor extension equal to the cylinder rod extension, and the left front and right front suspension oil cylinder rod extension displacement is recorded; the displacement sensor installed below the driver's seat is calibrated to record the seat balance position as the displacement zero point, and the relative displacement of the seat in the vertical direction is recorded.

[0010] In addition, the application also provides an evaluation method based on the smoothness evaluation system of the mine dump truck, comprising the following steps:

[0011] S1, obtaining a smoothness comprehensive evaluation value

[0012] S101, calculating a total weighted acceleration root mean square value matrix A v ;

[0013] S102, calculating a vehicle-road roughness matrix A r ;

[0014] S103, calculating a smoothness comprehensive evaluation value

[0015] S2, obtaining a seat comfort matrix

[0016] S201, calculating a seat speed comfort matrix A s ;

[0017] S202, setting a vehicle speed weighting coefficient matrix A kv , multiplying the vehicle speed weighting coefficient matrix by the seat speed comfort matrix to obtain a seat comfort matrix A sv ;

[0018] S203, importing the seat comfort matrix into a seat comfort classification chart to obtain a seat comfort level.

[0019] As an improvement, the total weighted acceleration root mean square value matrix A v in step S101 is composed of total weighted acceleration root mean square values A calculated at different specified speeds according to the “GB / T 4970-2009 Automobile Smoothness Test Method”.

[0020] As an improvement, the vehicle-road roughness matrix A r in step S102 is obtained by inverse normalization processing of vehicle-road roughness r at different specified speeds.

[0021]

[0022] A r =[r n1 r n2 … r nm ];

[0023] In the formula: a vni represents v n Weighted acceleration root mean square value of position i at vehicle speed;

[0024] The vehicle-road unevenness r is obtained by multiplying the standard deviation of the left front and right front suspension cylinder rod extension displacement by the left front and right front suspension cylinder rod displacement weighting coefficient, and the calculation formula is as follows: r=[s F s R ]×[k F k R ] T ;

[0025] The inverse normalization processing is inverse normalization calculation with the H-level road surface vehicle-road unevenness and the A-level road surface vehicle-road unevenness as the maximum and minimum values, and the calculation formula is as follows:

[0026] As an improvement, the ride comfort comprehensive evaluation value in step S103 is the vehicle-road unevenness matrix A r multiplied by the total weighted acceleration root mean square value matrix A v , and the calculation formula is as follows:

[0027] As an improvement, the seat vehicle speed comfort matrix A s in step S201 is the seat vertical overrun frequency N and the seat vertical relative speed effective value v sr at different specified vehicle speeds,

[0028] The overrun frequency N is to select a suitable threshold value according to the seat vertical stroke, and to count the frequency of the seat vertical relative displacement exceeding the threshold value within a unit time. The seat vertical relative speed effective value v sr is to calculate the effective value after the first derivative of the seat vertical relative speed, v sr =[X(2)-X(1) X(3)-X(2) … X(m)-X(m-1)] / f.

[0029] In the formula: X(m) represents the mth value of the seat vertical displacement data, and f represents the data sampling rate.

[0030] As an improvement, the vehicle speed weighting coefficient matrix A kv in step S202 is a matrix composed of different coefficients according to different specified vehicle speeds, A kv =[k v1 k v2 … k vn ] and

[0031] The seat comfort matrix A sv The calculation is as follows: A sv = A kv * A s = [N v sr ].

[0032] As an improvement, the seat comfort classification chart in step S203 is obtained by classifying the seat comfort through the subjective perception database of the excessive frequency and the effective value of the seat vertical relative speed, and drawing the seat comfort classification chart.

[0033] The principle of the present application is: using a three-axis accelerometer to collect the footrest, backrest and cushion vibration acceleration, using a displacement sensor to collect the left front and right front suspension oil cylinder rod displacement and seat vertical displacement. The data analysis module calculates the total weighted acceleration root mean square matrix of the acceleration data at different speeds and working conditions, and calculates the vehicle-road roughness matrix from the left front and right front oil cylinder rod displacement data. The total weighted acceleration root mean square matrix and the vehicle-road roughness matrix are multiplied to obtain the smoothness comprehensive evaluation value. The displacement of the seat vertical displacement is calculated to obtain the seat comfort matrix.

[0034] Compared with the prior art, the present application evaluates the smoothness of the mine dump truck through the smoothness comprehensive evaluation value and the seat comfort matrix, improves the problem that the existing smoothness method evaluation is inaccurate due to road conditions, vehicle speed, seat low-frequency large movement, etc., and improves the accuracy and transverse comparability of the smoothness evaluation result. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The figure is a schematic diagram of the principle structure of the present application;

[0036] Figure 2 The figure is a seat comfort classification chart of the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the present application will be further described in detail below. However, it should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the scope of the present application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs, and the terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0039] A smoothness evaluation system of a mine dump truck, comprising:

[0040] Data acquisition module, the data acquisition module includes several three-axis accelerometers, displacement sensors, respectively used for collecting vibration acceleration data and displacement data;

[0041] Data analysis module, the data analysis module is used for receiving vibration acceleration data and displacement data, and analyzing to obtain smoothness comprehensive evaluation value and seat comfort matrix.

[0042] As an embodiment, the data acquisition module includes three three-axis accelerometers and three displacement sensors;

[0043] The three-axis accelerometers are respectively installed at the seat cushion, the seat back and the foot position (the specific installation position is referred to GB / T 4970-2009 Automotive Road Test Methods), and the displacement sensors are respectively installed at the left front suspension oil cylinder, the right front suspension oil cylinder and the position below the seat;

[0044] The three-axis accelerometers are respectively used for measuring the vibration acceleration of the seat cushion, the seat back and the foot position, and the displacement sensors are respectively used for measuring the extension displacement of the left front and right front suspension oil cylinder rods and the vertical displacement of the seat; after calibration of the suspension oil cylinder rod displacement sensors, the sensor extension amount is equal to the cylinder rod extension amount, after calibration of the seat vertical displacement sensor, the seat balance position is recorded as the displacement zero point, the three-axis accelerometer range is not less than 50g, the sensitivity is not greater than 10mv / g, the displacement sensor range is not less than 1m, and the sensitivity is not greater than 1mv / mm. The sampling frequency of the data acquisition system is set to 1000Hz.

[0045] Before the test, it is necessary to confirm whether the vehicle state is normal, the test road needs 3 kilometers of straight road, the road longitudinal slope is not greater than 3%, and the road grade has no requirement. The test is divided into empty load smoothness test and rated load smoothness test, the empty load smoothness test is driven at 10, 20, 30 and 40km / h for 3 minutes, each speed is repeated three times, and the rated load smoothness test is driven at 8, 16 and 24km / h for 3 minutes, each speed is repeated three times.

[0046] Example 1

[0047] As Figure 1 shown, the calculation process of the data analysis module is introduced taking the whole vehicle empty load as an example, the whole vehicle rated load state calculation process is the same as the whole vehicle empty load, and the specific steps are as follows:

[0048] Step 1, refer to the random input driving test of GB / T 4970-2009 Automotive Road Test Methods to calculate the total weighted acceleration root mean square value of each position The weighted acceleration root mean square value of each position at each speed constitutes an acceleration root mean square value matrix A:

[0049]

[0050] In the formula: the rows correspond to the root mean square values ​​of weighted acceleration at each position under constant speeds of 10, 20, 30, and 40 km / h, respectively; the columns correspond to the root mean square values ​​of weighted acceleration at the foot pedal, backrest, and seat cushion, respectively.

[0051] Next, the root mean square value A of the total weighted acceleration at each vehicle speed was calculated using the "GB / T 4970-2009 Test Method for Ride Comfort of Automobiles". v :

[0052]

[0053] Step 2: Calculate the standard deviation s of the displacement of the left suspension cylinder under constant speeds of 10, 20, 30, and 40 km / h. F and the standard deviation of the right suspension displacement s R Considering that the cab is located at the front left of the vehicle, the weighting coefficients for the left and right side suspension displacements are set to 0.7 and 0.3, respectively. The vehicle-road unevenness r is obtained by multiplying the displacement standard deviation and the weighting coefficients.

[0054] r = [s F s R [0.7 0.3] T =0.7s F +0.3s R ;

[0055] The vehicle-road unevenness is obtained by inverse normalization. n :

[0056]

[0057] In the formula: r h For H-level road surface roughness, r a The road surface roughness is classified as Class A.

[0058] Obtain the road roughness matrix A for vehicles exiting at constant speeds of 10, 20, 30, and 40 km / h. r :

[0059] A r =[r n1 r n2 r n3 r n4 ];

[0060] Step 3: Calculate the overall ride comfort evaluation value using the vehicle-road unevenness matrix.

[0061] Step 4: Calculate the displacement of the driver's seat height obtained by the seat vertical displacement sensor. Use a threshold to judge the relative displacement of the seat and obtain the number of times the relative displacement reaches the threshold of 50mm per unit time, which is recorded as the over-limit frequency N.

[0062] The vertical relative velocity of the seat is obtained by differentiating the relative displacement of the seat, and then the effective value of the vertical relative velocity v is obtained. sr ;

[0063] v sr =[X(2)-X(1) X(3)-X(2)…X(m)-X(m-1)] / f;

[0064] In the formula: X(m) represents the m-th value of the seat vertical displacement data, and f represents the data sampling rate.

[0065] Calculate the frequency N and v of exceeding the limit while driving at constant speeds of 10, 20, 30, and 40 km / h. sr Obtain the seat speed comfort matrix A s :

[0066]

[0067] Set up a weighting coefficient matrix A for different vehicle speeds. kv :

[0068] A kv =[k v1 k v2 … k vn ]and

[0069] Calculate the seat comfort matrix A sv A sv =A kv ×A s =[N v sr ].

[0070] The frequency of exceeding the limit N and the effective value of the vertical relative velocity of the seat are combined in the seat comfort matrix. sr Substitute Figure 2 The chair comfort rating chart determines the seat comfort level and completes the judgment of seat comfort.

[0071] The seat comfort rating chart uses the frequency of exceeding limits as the horizontal axis and the effective value of vertical relative velocity as the vertical axis. Different frequency amplitude excitations are applied through a seat vibration test bench, and the subjects' subjective feelings are used to evaluate different frequencies of exceeding limits and effective values ​​of vertical relative velocity. A subjective feeling database of different frequencies of exceeding limits and effective values ​​of vertical relative velocity is obtained. The comfort of the seats is rated using this database, and the seat comfort rating chart is drawn.

[0072] The smoothness comprehensive evaluation value and the seat comfort matrix and the seat comfort level in the empty load state are obtained through the above calculation steps, the smoothness comprehensive evaluation value and the seat comfort matrix and the seat comfort level in the rated load state are calculated by using the same method, and thus the smoothness evaluation in the empty load state and the rated load state is completed.

[0073] Due to the above scheme, the displacement sensor is used to measure the vehicle-road roughness, the smoothness comprehensive evaluation value is obtained by using the vehicle-road roughness matrix and the total weighted acceleration root mean square matrix, the smoothness evaluation value is not greatly deviated due to the road roughness, the influence of the vehicle speed and the road condition on the smoothness calculation is excluded, the smoothness test requirement of the mine dump truck on the actual road in the mine area is met, the applicability of the smoothness test is improved, the problem of the large difference between the evaluation result and the subjective feeling of the driver is solved, the transverse comparison of the smoothness of the mine dump truck is realized, and the basis for the optimization of the smoothness of the whole vehicle is provided.

[0074] The low-frequency large-amplitude vibration (movement) of the suspended seat causes the discomfort of the driver, a seat vertical displacement sensor is used, the seat comfort matrix is obtained by calculating the seat vertical displacement overrun frequency and the vertical velocity effective value, the quantitative analysis of the dynamic comfort of the suspended seat is realized, and then the seat comfort matrix is brought into the seat comfort classification diagram to obtain the qualitative evaluation of the comfort of the seat.

[0075] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement or improvement within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An evaluation method of a mine dump truck-based smoothness evaluation system, characterized by, The smoothness evaluation system of the mine dump truck comprises a data acquisition module and a data analysis module. The method comprises the following steps: S1, obtaining a smoothness comprehensive evaluation value S101、calculate total weighted acceleration root mean square value matrix A v ; S102、calculating a vehicle-road roughness matrix A r ; the vehicle-road roughness matrix A r is inversely normalized by the vehicle-road roughness r at different specified vehicle speeds; A r ＝[r n1 r n2 …r nm ]； wherein: a vni represents v n Weighted acceleration root mean square value at position i at vehicle speed The vehicle-road unevenness r is obtained by multiplying the standard deviation of the displacement of the left front and right front suspension oil cylinder rods by the left front and right front suspension oil cylinder rod displacement weighting coefficient, and the calculation formula is as follows: r=[s F s R ]×[k F k R ] T ; The inverse normalization processing is inverse normalization calculation with the H-level road surface vehicle-road unevenness and the A-level road surface vehicle-road unevenness as the maximum value and the minimum value, and the calculation formula is as follows: S103、calculating the smoothness comprehensive evaluation value smoothness comprehensive evaluation value is a vehicle-road roughness matrix A r multiplied by the total weighted acceleration root mean square matrix A v obtained, and the calculation formula is as follows: S2, obtaining a seat comfort matrix S201、calculating the seat vehicle speed comfort matrix A s ; seat vehicle speed comfort matrix A s is the frequency N of the seat vertical overrun and the effective value v of the seat vertical relative speed at different specified vehicle speeds sr , The super-limit frequency N is a frequency of the seat vertical relative displacement exceeding a threshold value in a unit time, which is selected according to the seat vertical stroke, and the seat vertical relative speed effective value v sr is a speed effective value calculated after once differentiating the seat vertical relative speed, v sr =[X(2)-X(1) X(3)-X(2) … X(m)-X(m-1)] / f; In the formula, X(m) represents the mth value of the seat vertical displacement data, and f represents the data sampling rate. S202, setting a vehicle speed weighting coefficient matrix A kv A seat comfort matrix A is obtained by multiplying a vehicle speed weighting coefficient matrix by a seat vehicle speed comfort matrix sv ; the vehicle speed weighting coefficient matrix A kv is a matrix composed of different coefficient groups according to different specified vehicle speeds, A kv =[k v1 k v2 … k vn ]and The seat comfort matrix A sv The calculation is as follows: A sv = A kv x A s = [N v sr ]; S203, substituting the seat comfort matrix into a seat comfort classification diagram to obtain a seat comfort level; the seat comfort classification diagram is obtained by classifying the seat comfort through a subjective perception database of the excessive frequency and the seat vertical relative speed effective value.

2. The evaluation method of the smoothness evaluation system based on the mine dump truck according to claim 1, characterized in that, The total weighted acceleration root mean square value matrix A in the step S101 v is composed of total weighted acceleration root mean square values A calculated at different prescribed vehicle speeds.

3. The evaluation method of the smoothness evaluation system based on the mine dump truck according to claim 1, characterized in that, The data acquisition module comprises three triaxial accelerometers and three displacement sensors. The three triaxial accelerometers are respectively installed at the driver's cabin footrest, the seat cushion and the seat backrest. The three displacement sensors are respectively installed at the left front suspension oil cylinder, the right front suspension oil cylinder and below the driver's cabin seat, and are respectively used for measuring the left front suspension oil cylinder rod extension amount, the right front suspension oil cylinder rod extension amount and the driver's cabin seat vertical movement amount.

4. The evaluation method of a smoothness evaluation system based on a mine dump truck according to claim 3, characterized by, The displacement sensors installed at the left front and right front suspension oil cylinders are calibrated to make the sensor extension amount equal to the cylinder rod extension amount, and the left front and right front suspension oil cylinder rod extension displacement is recorded. The displacement sensor installed below the driver's cabin seat is calibrated to make the seat balance position as the displacement zero point, and the seat vertical relative displacement is recorded.

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