Fault detection methods and devices

Abstract

This invention relates to the field of fault detection technology, providing a fault detection method and apparatus. The method involves determining the fault detection type, including creeping vibration detection, vibration and noise detection, and output characteristic detection; adjusting the fault detection device to the creeping vibration detection mode corresponding to the creeping vibration detection type to perform creeping vibration detection on the tested hydraulic cylinder; adjusting the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type to perform vibration and noise detection on the tested hydraulic cylinder; and adjusting the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type to perform output characteristic detection on the tested hydraulic cylinder. By flexibly adjusting the fault detection device to the corresponding fault detection mode, creeping vibration, vibration and noise, and output characteristic detection can be automatically achieved, solving the problem of insufficient effectiveness of manual detection of hydraulic cylinder faults and effectively improving the fault detection efficiency of hydraulic cylinders.

Description

Technical Field

[0001] This invention relates to the field of fault detection technology, and in particular to a fault detection method and apparatus. Background Technology

[0002] Currently, fault detection devices for hydraulic cylinders in the industry mainly focus on testing the cylinder's sealing performance, without addressing the research and analysis of cylinder creep / vibration, vibration / abnormal noise, and output characteristics. However, in practical applications, creep / vibration and vibration / abnormal noise faults in hydraulic cylinders have a significant impact on the safe and reliable operation of the main unit. For example, for crane telescopic cylinders, creep / vibration can cause difficulties in positioning heavy objects and even create safety risks; for excavator boom cylinders, abnormal noise can severely affect the user experience, and after prolonged operation, serious problems such as oil leakage from the boom seal and damage to the boom cylinder can occur; for pump main cylinders, abnormal output characteristics can directly affect the pumping range and working efficiency of the pumping system.

[0003] However, faults such as crawling vibration, abnormal noise, and output characteristics of hydraulic cylinders are mainly detected manually, resulting in insufficient fault detection rate and relatively low fault detection efficiency. Summary of the Invention

[0004] This invention provides a fault detection method and apparatus to address the shortcomings of existing technologies where faults related to hydraulic cylinder crawling vibration, abnormal noise, and output characteristics are mainly detected manually.

[0005] This invention provides a fault detection method, the method comprising:

[0006] Determine the fault detection type, which includes crawling vibration detection type, vibration and abnormal noise detection type, and output characteristic detection type;

[0007] Adjust the fault detection device to the crawling vibration detection mode corresponding to the crawling vibration detection type, and perform crawling vibration detection on the tested hydraulic cylinder;

[0008] Adjust the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type, and perform vibration and noise detection on the tested hydraulic cylinder;

[0009] Adjust the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type, and perform output characteristic detection on the tested hydraulic cylinder.

[0010] According to a fault detection method provided by the present invention, the step of performing creeping vibration detection on the tested hydraulic cylinder includes:

[0011] Calculate the absolute value of the average speed difference of the tested cylinder within any two adjacent first sampling periods;

[0012] Compare the absolute value of the average speed difference with the magnitude of the first error threshold;

[0013] If the absolute value of the average speed difference is greater than the first error threshold, then it is determined that the tested cylinder has a crawling vibration fault in the adjacent first sampling period.

[0014] According to a fault detection method provided by the present invention, the calculation of the absolute value of the average speed difference of the tested hydraulic cylinder within any two adjacent first sampling periods includes:

[0015] Collect the displacement value of the tested hydraulic cylinder at the previous moment and the displacement value at the current moment;

[0016] Determine the first average speed of the tested hydraulic cylinder between the previous moment and the current moment;

[0017] The displacement value of the tested hydraulic cylinder at the next moment is collected, and the second average velocity of the tested hydraulic cylinder between the current moment and the next moment is calculated.

[0018] Calculate the absolute value of the difference between the first average speed and the second average speed;

[0019] The previous time and the current time, as well as the current time and the next time, are all separated by the first sampling period.

[0020] A fault detection method according to the present invention further includes:

[0021] If the absolute value of the average speed difference is less than or equal to the first error threshold, then it is determined whether the displacement value at the next moment has reached the travel limit.

[0022] If the displacement value at the next moment reaches the stroke limit, then calculate the average, maximum and minimum values ​​of the speed of the tested cylinder in all first sampling periods;

[0023] When the absolute value of the difference between the average value and the maximum value is less than the first error threshold, and the absolute value of the difference between the average value and the minimum value is less than the first error threshold, it is determined that the tested cylinder has no crawling vibration fault.

[0024] If the displacement value at the next moment does not reach the travel limit, then the current moment is updated as the previous moment, the next moment is updated as the current moment, and the time interval between the next moment and the first sampling period is updated as the next moment.

[0025] According to a fault detection method provided by the present invention, the vibration and abnormal noise detection of the tested hydraulic cylinder includes:

[0026] The initial vibration value of the tested hydraulic cylinder was collected when it was not in operation.

[0027] During the operation of the tested hydraulic cylinder, the real-time vibration value of the tested hydraulic cylinder is collected at a time interval of the second sampling period;

[0028] If the absolute value of the difference between the real-time vibration value and the initial vibration value is greater than the second error threshold, then it is determined that the tested cylinder has a vibration and noise fault within the stroke corresponding to the real-time vibration value.

[0029] According to a fault detection method provided by the present invention, output characteristic detection is performed on a tested hydraulic cylinder, including:

[0030] The thrust value and rod chamber pressure of the tested hydraulic cylinder under the outward pushing condition, or the tension value and rodless chamber pressure under the pull-back condition, are collected at each sampling time interval using the third sampling period as the time interval.

[0031] Based on the thrust value and the rod chamber pressure, determine the outward load efficiency of the tested cylinder at each sampling time; or, based on the pull value and the rodless chamber pressure, determine the pullback load efficiency of the tested cylinder at each sampling time.

[0032] If the extrapolated load efficiency or the pullback load efficiency is greater than or equal to the preset efficiency, then the tested cylinder is determined to be in a normal state.

[0033] A fault detection method according to the present invention further includes:

[0034] If the extrapolated load efficiency or the pullback load efficiency is less than the preset efficiency, then it is detected whether the stroke at the sampling time corresponding to the extrapolated load efficiency or the pullback load efficiency is within the buffer zone of the tested cylinder.

[0035] If the stroke at the sampling time corresponding to the extrapolation load efficiency or the pullback load efficiency is not in the buffer zone of the tested cylinder, then compare the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pullback condition with the magnitude of the allowable back pressure.

[0036] If the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pullback condition is greater than the allowable back pressure, then it is determined that there is an output characteristic fault caused by excessive back pressure within the stroke corresponding to the acquisition time.

[0037] A fault detection method according to the present invention further includes:

[0038] If the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pullback condition is less than or equal to the allowable back pressure, then it is determined that there is an output characteristic fault caused by mechanical jamming within the stroke corresponding to the acquisition time.

[0039] According to a fault detection method provided by the present invention, the fault detection device includes: a test bench, a test equipment, a test cylinder, an off-center loading cylinder, a lifting cylinder, a tension cylinder, a fixed pin, and a movable support.

[0040] One end of the test bench is fixed to the ground via the fixed pin, and the other end of the test bench is fixed to the ground via the movable bracket; the bottom of the auxiliary test cylinder is fixed to the test bench surface at the opposite end to the test cylinder, and the piston rod of the auxiliary test cylinder is mechanically connected to the test equipment; the piston rod of the offset loading cylinder is mechanically connected to the guide sleeve of the test cylinder; the bottom of the lifting cylinder is fixed to the ground, and the piston rod of the lifting cylinder is mechanically connected to the test bench; the bottom of the tension cylinder is fixed to the ground, and the piston rod of the tension cylinder is mechanically connected to the test bench.

[0041] The bottom of the test cylinder is fixed to the test bench. The test equipment, the accompanying cylinder, the offset loading cylinder, the lifting cylinder, and the tension cylinder are used to adjust the fault detection device to the crawling vibration detection mode, the vibration and abnormal noise detection mode, and the output characteristic detection mode.

[0042] The present invention also provides a fault detection device, comprising:

[0043] The determination module is used to determine the fault detection type, which includes crawling vibration detection type, vibration and abnormal noise detection type, and output characteristic detection type;

[0044] The creeping vibration detection module is used to adjust the fault detection device to the creeping vibration detection mode corresponding to the creeping vibration detection type, and to perform creeping vibration detection on the tested hydraulic cylinder.

[0045] The vibration and noise detection module is used to adjust the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type, and to perform vibration and noise detection on the tested hydraulic cylinder.

[0046] The output characteristic detection module is used to adjust the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type, and to perform output characteristic detection on the tested hydraulic cylinder.

[0047] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the fault detection methods described above.

[0048] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the fault detection methods described above.

[0049] This invention provides a fault detection method and apparatus. The method involves determining the fault detection type, which includes creeping vibration detection, vibration and noise detection, and output characteristic detection. The method then adjusts the fault detection device to the creeping vibration detection mode corresponding to the creeping vibration detection type to perform creeping vibration detection on the tested hydraulic cylinder. Next, it adjusts the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type to perform vibration and noise detection on the tested hydraulic cylinder. Finally, it adjusts the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type to perform output characteristic detection on the tested hydraulic cylinder. By flexibly adjusting the fault detection device to the corresponding fault detection mode, creeping vibration, vibration and noise, and output characteristic detection can be automatically achieved, improving both the fault detection rate and the efficiency of hydraulic cylinder fault detection. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 This is a flowchart illustrating the fault detection method provided by the present invention;

[0052] Figure 2 This is a schematic diagram of the crawling jitter fault detection process provided by the present invention;

[0053] Figure 3 This is a schematic diagram of the vibration and noise fault detection process provided by the present invention;

[0054] Figure 4 This is a schematic diagram of the output characteristic fault detection process provided by the present invention;

[0055] Figure 5 This is a schematic diagram of the physical fault detection device provided by the present invention;

[0056] Figure 6 This is a schematic diagram of the structure of the virtual fault detection device provided by the present invention;

[0057] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention;

[0058] Figure label:

[0059] 1. Test bench; 2. Test equipment; 3. Test cylinder; 4. Offset loading cylinder; 5. Lifting cylinder; 6. Pull-back cylinder; 7. Fixed pin; 8. Movable support; A. Test cylinder; B. Ground. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0061] The following is combined with Figures 1 to 7 This invention describes a fault detection method and apparatus.

[0062] Figure 1 This is a flowchart illustrating the fault detection method provided by the present invention.

[0063] like Figure 1 As shown in the figure, the fault detection method provided by this embodiment of the invention can be executed by the control system of a fault detection device, wherein the tested cylinder includes a hydraulic cylinder, etc., and the method mainly includes the following steps:

[0064] 101. Determine the fault detection type. Fault detection types include crawling vibration detection type, vibration and abnormal noise detection type, and output characteristic detection type.

[0065] In a specific implementation process, the hydraulic cylinder that needs to be fault detected is defined as the test cylinder. First, the fault detection type of the hydraulic cylinder must be determined. The fault detection type of the hydraulic cylinder can be determined by obtaining the fault detection type input by the user through a human-machine interface, or by performing fault detection according to a preset fault detection method. Among them, the fault detection types include creeping vibration detection type, vibration and abnormal noise detection type, and output characteristic detection type.

[0066] 102. Adjust the fault detection device to the creep vibration detection mode corresponding to the creep vibration detection type, and perform creep vibration detection on the tested cylinder.

[0067] Because the fault detection device tests the hydraulic cylinder under test, its configuration can be adjusted. It can test the cylinder under no-load conditions or under load. The fault detection device can be adjusted to the fault detection mode corresponding to the fault detection type according to the user's actual needs. The creeping vibration detection mode includes multiple options, and can be performed under no-load conditions or under load; the specific mode can be determined based on the user's actual requirements.

[0068] 103. Adjust the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type, and perform vibration and noise detection on the tested cylinder.

[0069] Specifically, if vibration and noise detection is required, the fault detection device needs to be adjusted to the corresponding vibration and noise detection mode. Whether to apply a load can be determined according to the user's actual needs. Vibration and noise detection can also be performed with or without a load, thereby ensuring more comprehensive fault detection.

[0070] 104. Adjust the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type, and perform output characteristic detection on the tested cylinder.

[0071] Similarly, if it is necessary to test the output characteristics of the tested hydraulic cylinder, the fault detection device needs to be adjusted to the corresponding output characteristic detection state. That is, the tested hydraulic cylinder needs to be under load, and fault detection should be performed on the tested hydraulic cylinder under load. The load includes axial load and radial off-center load, etc., to more realistically simulate actual working conditions and ensure the accuracy of fault detection results.

[0072] There is no specific order for steps 102, 103 and 104; they can be executed sequentially or simultaneously.

[0073] This embodiment provides a fault detection method that, by determining the fault detection type (including creeping vibration detection, vibration and noise detection, and output characteristic detection), adjusts the fault detection device to the creeping vibration detection mode corresponding to the creeping vibration detection type to perform creeping vibration detection on the tested hydraulic cylinder; adjusts the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type to perform vibration and noise detection on the tested hydraulic cylinder; and adjusts the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type to perform output characteristic detection on the tested hydraulic cylinder. By flexibly adjusting the fault detection device to the corresponding fault detection mode, creeping vibration, vibration and noise, and output characteristics can be automatically detected, improving both the fault detection rate and the efficiency of hydraulic cylinder fault detection.

[0074] Furthermore, based on the above embodiments, this embodiment performs crawling vibration detection on the tested hydraulic cylinder, including: calculating the absolute value of the average speed difference of the tested hydraulic cylinder in any two adjacent first sampling periods; comparing the absolute value of the average speed difference with the magnitude of a first error threshold; if the absolute value of the average speed difference is greater than the first error threshold, it is determined that the tested hydraulic cylinder has a crawling vibration fault in adjacent first sampling periods.

[0075] The calculation of the absolute value of the average velocity difference of the test cylinder within any two adjacent first sampling periods includes: collecting the displacement value of the test cylinder at the previous moment and the displacement value at the current moment; determining the first average velocity of the test cylinder between the previous moment and the current moment; collecting the displacement value of the test cylinder at the next moment and calculating the second average velocity of the test cylinder between the current moment and the next moment; and calculating the absolute value of the difference between the first average velocity and the second average velocity. The previous moment and the current moment, as well as the current moment and the next moment, are separated by the first sampling period.

[0076] Specifically, the principle for detecting whether the test cylinder has a crawling vibration fault is to compare the difference between the average speeds of the test cylinder in adjacent cycles. If the difference is within the first error threshold, it is determined that there is no crawling vibration fault; otherwise, it is determined that the test cylinder has a crawling vibration fault.

[0077] Figure 2 This is a schematic diagram of the crawling jitter fault detection process provided by the present invention.

[0078] like Figure 2 As shown, when performing crawling vibration fault detection, the first sampling period is set to t, the stroke of the tested cylinder is X, and the first error threshold is δ1. The tested sample is fully vented and tested to prepare for the test. The determination of t, X and δ1 can be input by the user through the human-machine interface.

[0079] Then, initialize n=1, i=1, and collect the data from the previous time step T. n The displacement value at time (=T1+n*t) is denoted as X. n The data is collected at the next time point after the first sampling period, i.e., T, which is the interval between the previous time point and the previous time point. n+1 (=T n The displacement value X at time +t) n+1 ; Calculate the previous time T n Up to the current time T n+1 First average velocity V between time periods n =(X n+1 -X n ) / t, stored in table V i Then, the next time interval, T, is collected after the first sampling period from the current time. n+2(=T n+1 The displacement value X at time +t) n+2 And calculate the current time T. n+1 Until the next moment T n+2 Second average velocity V between time periods n+1 =(X n+2 -X n+1 ) / t, stored in table V i+1 Finally, calculate the first average velocity V. i With the second average velocity V i+1 The absolute value of the difference; if the absolute value of the difference is greater than the first error threshold δ1, then it is determined that the error range is from Xn to X. n+2 There is a crawling jitter error within the travel period, and the human-computer interaction interface outputs "During travel period Xn to X..." n+2 "Crawling / vibration fault exists in the interval." Here, the previous, current, and next moments can be any moment, i.e., any moment during the testing of the tested hydraulic cylinder. That is, the crawling / vibration fault detection process is executed cyclically, such as... Figure 2 As shown, after the detection of the two adjacent cycles is completed, the crawling jitter fault detection of the next adjacent cycle is performed.

[0080] Furthermore, such as Figure 2 As shown, if the absolute value of the average speed difference is less than or equal to the first error threshold, it is determined whether the displacement value at the next moment has reached the stroke limit; if the displacement value at the next moment has reached the stroke limit, the average, maximum, and minimum speeds of the tested cylinder in all the first sampling periods are calculated; when the absolute value of the difference between the average and the maximum is less than the first error threshold, and the absolute value of the difference between the average and the minimum is less than the first error threshold, it is determined that the tested cylinder has no crawling vibration fault; if the displacement value at the next moment has not reached the stroke limit, the current moment is updated as the previous moment after the update, the next moment is updated as the current moment after the update, and the time interval between the next moment and the first sampling period is updated as the next moment after the update.

[0081] Specifically, if the absolute value of the average velocity difference is less than or equal to the first error threshold, it is necessary to determine the next time step T. n+2 (=T n+1 +t) corresponds to the journey X n+2 Has the travel limit been reached? If at the next moment T... n+2 (=T n+1If the displacement value of (+t) does not reach the travel limit X, it indicates that crawling jitter fault detection needs to continue. This involves updating the values ​​of n and i, using the current time in the previous test loop as the updated previous time, the next time as the updated current time, and the time interval between the next and the first sampling period as the updated next time, i.e., n = n + 3, i = i + 3. This crawling jitter detection is performed cyclically until the collected travel reaches the travel limit.

[0082] If the next moment T is determined n+2 (=T n+1 +t) corresponds to the journey X n+2 If the travel limit is reached, it is necessary to re-detect crawling jitter within all intervals corresponding to all first sampling periods. First, calculate the average value V of the tested cylinder speed over all first sampling periods. a =average(V1:V i ), maximum value V b =max(V1:V i Minimum value V c =min(V1:V i Compare the maximum values ​​V respectively. b and the minimum value V c With average value V a The relationship between their magnitudes, if δ1 < |V b -V a | and, δ1 < |V c -V a If the value is |, then it is determined that there may be a crawling jitter fault. Therefore, it is necessary to retest the crawling jitter within the travel range corresponding to the speed extreme value. Otherwise, it is determined that there is no crawling jitter fault.

[0083] Furthermore, based on the above embodiments, this embodiment performs vibration and noise detection on the tested hydraulic cylinder, including: collecting the initial vibration value of the tested hydraulic cylinder in a non-working state; during the working process of the tested hydraulic cylinder, collecting the real-time vibration value of the tested hydraulic cylinder at a second sampling period as the time interval; if the absolute value of the difference between the real-time vibration value and the initial vibration value is greater than the second error threshold, it is determined that there is a vibration and noise fault in the tested hydraulic cylinder within the stroke corresponding to the real-time vibration value.

[0084] Specifically, Figure 3 This is a schematic diagram of the vibration and noise fault detection process provided by the present invention, as shown below. Figure 3 As shown, before using the hydraulic cylinder fault detection device to detect vibration and abnormal noise, the test cylinder is first fully tested and vented to determine the second sampling period t, the stroke X, and the second error threshold δ2. The second sampling period can be the same as the first sampling period, which is t, and the stroke can also be the same, which is X.

[0085] After the preparation work is completed, the fault detection of vibration and abnormal noise needs to be carried out. First, the initial vibration value of the test cylinder in the non-working state, i.e., the stationary state, is collected and recorded as Y. 初 Then, the tested hydraulic cylinder begins to move under the drive of the hydraulic station. During the operation of the tested hydraulic cylinder, sampling is performed at time intervals of the second sampling period t, that is, the vibration value is sampled once every second sampling period to obtain the real-time vibration value at each sampling moment, and the real-time vibration value Y collected each time is recorded. t The corresponding displacement value X t Movement, compare real-time vibration value Y t With the initial displacement value Y 初 The size, if δ2 < |Y t -Y 初 |, then determine in itinerary X t The memory is experiencing vibration and abnormal noise faults, δ2≥|Y t -Y 初 If the current stroke is confirmed to be free of vibration or abnormal noise, then the vibration value is sampled and detected again at the second interval, and the detection is repeated until all strokes are collected, that is, after the stroke of the tested cylinder reaches its limit, the detection ends.

[0086] Furthermore, based on the above embodiments, this embodiment performs output characteristic detection on the tested hydraulic cylinder, including: acquiring the thrust value and rod chamber pressure of the tested hydraulic cylinder under the outward pushing condition at each sampling time interval, or the tension value and rodless chamber pressure under the pull-back condition, with the third sampling period as the time interval; determining the outward load efficiency of the tested hydraulic cylinder at each sampling time based on the thrust value and rod chamber pressure, or determining the pull-back load efficiency of the tested hydraulic cylinder at each sampling time based on the tension value and rodless chamber pressure; if the outward load efficiency or pull-back load efficiency is greater than or equal to the preset efficiency, then the tested hydraulic cylinder is determined to be in a normal state.

[0087] If the extrapolated load efficiency or pull-back load efficiency is less than the preset efficiency, then it is checked whether the stroke at the sampling time corresponding to the extrapolated load efficiency or pull-back load efficiency is within the buffer zone of the tested cylinder. If the stroke at the sampling time corresponding to the extrapolated load efficiency or pull-back load efficiency is not within the buffer zone of the tested cylinder, then the rod chamber pressure under the extrapolated condition or the rodless chamber pressure under the pull-back condition is compared with the allowable back pressure. If the rod chamber pressure under the extrapolated condition or the rodless chamber pressure under the pull-back condition is greater than the allowable back pressure, then it is determined that there is an output characteristic fault caused by excessive back pressure within the stroke corresponding to the sampling time. If the rod chamber pressure under the extrapolated condition or the rodless chamber pressure under the pull-back condition is less than or equal to the allowable back pressure, then it is determined that there is an output characteristic fault caused by mechanical jamming within the stroke corresponding to the sampling time.

[0088] Specifically, the core principle of output characteristic fault detection is to simulate the loading motion of the tested hydraulic cylinder under load. Based on the load efficiency of the tested hydraulic cylinder and the pressure in the rod chamber and rodless chamber, it is determined whether the output efficiency is abnormal. The tested hydraulic cylinder operates in two conditions: an outward thrust condition and a backward thrust condition. The outward thrust condition corresponds to a thrust value f. 1t With rod chamber pressure P 1t The pullback condition corresponds to the tensile force value f. 2t With rodless chamber pressure P 2t .

[0089] Figure 4 This is a schematic diagram of the output characteristic fault detection process provided by the present invention.

[0090] like Figure 4 As shown, before performing output characteristic fault detection, the third sampling period t, the stroke X of the tested cylinder, and the buffer stroke X are first determined. 缓 Cylinder diameter a, rod diameter b, preset efficiency η 下 Allow back pressure δ3, then perform a full test run of the test cylinder and vent the air, control the test cylinder to move under the drive of the hydraulic station, and after the preparation work is completed, start the output characteristic fault detection.

[0091] Specifically, the thrust value f of the tested hydraulic cylinder under extrapolated working conditions is collected at each sampling time interval using the third sampling period as the time interval. 1t With rod chamber pressure P 1t Or the tensile force f under pullback conditions. 2t With rodless chamber pressure P 2t The sampling time includes any moment from the start of operation of the tested hydraulic cylinder to the point where it reaches its limit stroke X.

[0092] Due to the thrust value f 1t Rod chamber pressure P 1t Tension value f 2t Rodless chamber pressure P 2t Since the cylinder diameter a and rod diameter b are known quantities, the load efficiency at time t can be calculated. If the test cylinder at time t is in the outward working condition, the outward load efficiency under the outward working condition is calculated using formula (1). If the test cylinder at time t is in the pull-back working condition, the pull-back load efficiency under the pull-back working condition is calculated using formula (2).

[0093]

[0094]

[0095] Where, η 1t Indicates the extrapolated load efficiency, η 2tIndicates pull-back load efficiency, a represents cylinder diameter, b represents rod diameter, f represents... 1t Indicates thrust value, P 1t Indicates rod chamber pressure, f 2t Indicates the tensile force value, P 2t This indicates the pressure in the rodless chamber.

[0096] After obtaining the extrapolated load efficiency and the pullback load efficiency, the extrapolated load efficiency η is compared respectively. 1t Pull-back load efficiency η 2t With preset efficiency η 下 The size, if η 1t ≥η 下 , and η 2t ≥η 下 If the test cylinder has no output characteristic fault, it is determined that it is in a normal state. Otherwise, if the test cylinder has an output characteristic fault, it is necessary to determine the type of output characteristic fault.

[0097] like Figure 4 As shown, the way to determine the fault type of the output characteristic is to check whether the stroke at the corresponding sampling time is in the buffer of the tested cylinder when the extrapolated load efficiency or the pullback load efficiency is less than the preset efficiency. If it is in the buffer, the sampling detection is performed at the next sampling time, and the detection is performed in a loop.

[0098] When the extrapolation load efficiency or pullback load efficiency is less than the preset efficiency, the stroke at the corresponding sampling time is not in the buffer. Then, it is determined whether the rod chamber pressure under the extrapolation condition is greater than the allowable back pressure δ3. If it is greater, it indicates that there is an output characteristic fault in the stroke at the sampling time, and the cause of the fault is excessive back pressure. If it is less, it indicates that the cause of the output characteristic fault in the stroke at the sampling time is mechanical jamming.

[0099] In the above embodiments, the first sampling period t, the second sampling period t, and the third sampling period t are the same, and the limit stroke X of the tested oil cylinder is the same.

[0100] Figure 5 This is a schematic diagram of the physical fault detection device provided by the present invention.

[0101] like Figure 5As shown, the fault detection device in this embodiment includes: a test bench 1, a test equipment 2, a test cylinder 3, an offset loading cylinder 4, a lifting cylinder 5, a tension cylinder 6, a fixed pin 7, and a movable support 8; one end of the test bench 1 is fixed to ground B via the fixed pin 7, and the other end of the test bench 1 is fixed to ground B via the movable support 8; the bottom of the test cylinder 3 is fixed to the test bench 1 at the opposite end to the test cylinder A, and the piston rod of the test cylinder 3 is mechanically connected to the test equipment 2; the piston rod of the offset loading cylinder 4... The piston rod is mechanically connected to the guide sleeve of the tested cylinder A; the bottom of the lifting cylinder 5 is fixed to the ground B, and the piston rod of the lifting cylinder 5 is mechanically connected to the test bench 1; the bottom of the tension cylinder 6 is fixed to the ground B, and the piston rod of the tension cylinder 6 is mechanically connected to the test bench 1; the bottom of the tested cylinder A is fixed to the table surface of the test bench; the test equipment 2, the accompanying cylinder 3, the off-center loading cylinder 4, the lifting cylinder 5, and the tension cylinder 6 are used to adjust the fault detection device to the crawling vibration detection mode, the vibration and abnormal noise detection mode, and the output characteristic detection mode.

[0102] In the specific implementation process, in order to more closely resemble real working conditions, during fault detection, it is necessary to start the hydraulic power source of the tested cylinder and drive the tested cylinder to reciprocate several times throughout its full stroke to fully expel air from the tested cylinder and hydraulic circuit. Then, based on the working posture of the tested cylinder under actual working conditions, the lifting cylinder at the bottom left end of the test bench is used to control the test bench and the test equipment, auxiliary cylinder, and off-center load cylinder on the test bench to rotate around the fixed pin as the center, adjusting the posture of the test bench. According to the actual working conditions of the tested cylinder, the off-center loading force of the radial loading cylinder is set through the off-center load cylinder, and the axial loading load force is set through the auxiliary cylinder. The tested cylinder begins to move under the drive of the hydraulic station, thus enabling different fault detections of the tested cylinder, including creeping vibration detection, vibration and abnormal noise detection, and output characteristic detection.

[0103] The fault detection method provided by this invention can accurately and quickly complete the detection of crawling vibration, vibration and abnormal noise, and output characteristics of the tested hydraulic cylinder. Compared with manual detection methods, it effectively improves the efficiency of fault detection. By efficiently detecting crawling vibration, vibration and abnormal noise, and output characteristic faults, the quality of hydraulic cylinders installed on the operating machinery is improved, while also ensuring the safe and reliable operation of the tested hydraulic cylinders on the main machine, thus reducing the incidence of safety accidents.

[0104] Based on the same general inventive concept, this invention also protects a fault detection device. The fault detection device provided by this invention will be described below. The fault detection device described below and the fault detection method described above can be referred to in correspondence.

[0105] Figure 6 This is a schematic diagram of the structure of the virtual fault detection device provided by the present invention.

[0106] like Figure 6 As shown, this embodiment provides a fault detection device, including:

[0107] The determination module 601 is used to determine the fault detection type, which includes crawling vibration detection type, vibration and abnormal noise detection type, and output characteristic detection type.

[0108] The creeping vibration detection module 602 is used to adjust the fault detection device to the creeping vibration detection mode corresponding to the creeping vibration detection type, and to perform creeping vibration detection on the tested hydraulic cylinder.

[0109] Vibration and noise detection module 603 is used to adjust the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type, and to perform vibration and noise detection on the tested hydraulic cylinder.

[0110] The output characteristic detection module is used to adjust the fault detection device to the output characteristic detection mode 604 corresponding to the output characteristic detection type, and to perform output characteristic detection on the tested hydraulic cylinder.

[0111] This embodiment provides a fault detection device that determines the fault detection type, including creeping vibration detection, vibration and noise detection, and output characteristic detection. The device is adjusted to the creeping vibration detection mode corresponding to the creeping vibration detection type to perform creeping vibration detection on the tested hydraulic cylinder; the device is also adjusted to the vibration and noise detection mode corresponding to the vibration and noise detection type to perform vibration and noise detection on the tested hydraulic cylinder; and the device is further adjusted to the output characteristic detection mode corresponding to the output characteristic detection type to perform output characteristic detection on the tested hydraulic cylinder. By flexibly adjusting the fault detection device to the corresponding fault detection mode, creeping vibration, vibration and noise, and output characteristic detection can be automatically achieved, improving both the fault detection rate and the efficiency of hydraulic cylinder fault detection.

[0112] Furthermore, the crawling jitter detection module 602 in this embodiment is specifically used for:

[0113] Calculate the absolute value of the average speed difference of the tested cylinder within any two adjacent first sampling periods;

[0114] Compare the absolute value of the average speed difference with the magnitude of the first error threshold;

[0115] If the absolute value of the average speed difference is greater than the first error threshold, then it is determined that the tested cylinder has a crawling vibration fault in the adjacent first sampling period.

[0116] Furthermore, the crawling jitter detection module 602 in this embodiment is specifically used for:

[0117] Collect the displacement value of the tested hydraulic cylinder at the previous moment and the displacement value at the current moment;

[0118] Determine the first average speed of the tested hydraulic cylinder between the previous moment and the current moment;

[0119] The displacement value of the tested hydraulic cylinder at the next moment is collected, and the second average velocity of the tested hydraulic cylinder between the current moment and the next moment is calculated.

[0120] Calculate the absolute value of the difference between the first average speed and the second average speed;

[0121] The previous time and the current time, as well as the current time and the next time, are all separated by the first sampling period.

[0122] Furthermore, the crawling jitter detection module 602 in this embodiment is specifically used for:

[0123] If the absolute value of the average speed difference is less than or equal to the first error threshold, then it is determined whether the displacement value at the next moment has reached the travel limit.

[0124] If the displacement value at the next moment reaches the stroke limit, then calculate the average, maximum and minimum values ​​of the speed of the tested cylinder in all first sampling periods;

[0125] When the absolute value of the difference between the average value and the maximum value is less than the first error threshold, and the absolute value of the difference between the average value and the minimum value is less than the first error threshold, it is determined that the tested cylinder has no crawling vibration fault.

[0126] If the displacement value at the next moment does not reach the travel limit, then the current moment is updated as the previous moment, the next moment is updated as the current moment, and the time interval between the next moment and the first sampling period is updated as the next moment.

[0127] Furthermore, the vibration and noise detection module 603 in this embodiment is specifically used for:

[0128] The initial vibration value of the tested hydraulic cylinder was collected when it was not in operation.

[0129] During the operation of the tested hydraulic cylinder, the real-time vibration value of the tested hydraulic cylinder is collected at a time interval of the second sampling period;

[0130] If the absolute value of the difference between the real-time vibration value and the initial vibration value is greater than the second error threshold, then it is determined that the tested cylinder has a vibration and noise fault within the stroke corresponding to the real-time vibration value.

[0131] Furthermore, the output characteristic detection 604 in this embodiment is specifically used for:

[0132] The thrust value and rod chamber pressure of the tested hydraulic cylinder under the outward pushing condition, or the tension value and rodless chamber pressure under the pull-back condition, are collected at each sampling time interval using the third sampling period as the time interval.

[0133] Based on the thrust value and the rod chamber pressure, determine the outward load efficiency of the tested cylinder at each sampling time; or, based on the pull value and the rodless chamber pressure, determine the pullback load efficiency of the tested cylinder at each sampling time.

[0134] If the extrapolated load efficiency or the pullback load efficiency is greater than or equal to the preset efficiency, then the tested cylinder is determined to be in a normal state.

[0135] Furthermore, the output characteristic detection 604 in this embodiment is specifically used for:

[0136] If the extrapolated load efficiency or the pullback load efficiency is less than the preset efficiency, then it is detected whether the stroke at the sampling time corresponding to the extrapolated load efficiency or the pullback load efficiency is within the buffer zone of the tested cylinder.

[0137] If the stroke at the sampling time corresponding to the extrapolation load efficiency or the pullback load efficiency is not in the buffer zone of the tested cylinder, then compare the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pullback condition with the magnitude of the allowable back pressure.

[0138] If the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pullback condition is greater than the allowable back pressure, then it is determined that there is an output characteristic fault caused by excessive back pressure within the stroke corresponding to the acquisition time.

[0139] Furthermore, the output characteristic detection 604 in this embodiment is specifically used for:

[0140] If the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pullback condition is less than or equal to the allowable back pressure, then it is determined that there is an output characteristic fault caused by mechanical jamming within the stroke corresponding to the acquisition time.

[0141] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention.

[0142] like Figure 7As shown, the electronic device may include a processor 710, a communications interface 720, a memory 730, and a communication bus 740, wherein the processor 710, communications interface 720, and memory 730 communicate with each other via the communication bus 740. The processor 710 can call logical instructions in the memory 730 to execute a fault detection method. This method includes: determining a fault detection type, which includes a crawling vibration detection type, a vibration and noise detection type, and an output characteristic detection type; adjusting the fault detection device to the crawling vibration detection mode corresponding to the crawling vibration detection type, and performing crawling vibration detection on the tested cylinder; adjusting the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type, and performing vibration and noise detection on the tested cylinder; and adjusting the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type, and performing output characteristic detection on the tested cylinder.

[0143] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0144] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, wherein when the program instructions are executed by a computer, the computer is able to execute the fault detection method provided by the above methods, the method comprising: determining a fault detection type, the fault detection type including a crawling vibration detection type, a vibration and noise detection type, and an output characteristic detection type; adjusting the fault detection device to the crawling vibration detection mode corresponding to the crawling vibration detection type, and performing crawling vibration detection on the tested hydraulic cylinder; adjusting the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type, and performing vibration and noise detection on the tested hydraulic cylinder; adjusting the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type, and performing output characteristic detection on the tested hydraulic cylinder.

[0145] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, is implemented to perform the fault detection methods provided above. The method includes: determining a fault detection type, the fault detection type including a crawling vibration detection type, a vibration and noise detection type, and an output characteristic detection type; adjusting a fault detection device to a crawling vibration detection mode corresponding to the crawling vibration detection type, and performing crawling vibration detection on the tested hydraulic cylinder; adjusting the fault detection device to a vibration and noise detection mode corresponding to the vibration and noise detection type, and performing vibration and noise detection on the tested hydraulic cylinder; and adjusting the fault detection device to an output characteristic detection mode corresponding to the output characteristic detection type, and performing output characteristic detection on the tested hydraulic cylinder.

[0146] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0147] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fault detection method, characterized in that, The methods include: Determine the fault detection type, which includes crawling vibration detection type, vibration and abnormal noise detection type, and output characteristic detection type; Adjust the fault detection device to the crawling vibration detection mode corresponding to the crawling vibration detection type, and perform crawling vibration detection on the tested hydraulic cylinder; Adjust the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type, and perform vibration and noise detection on the tested hydraulic cylinder; Adjust the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type, and perform output characteristic detection on the tested hydraulic cylinder; The output characteristics of the tested hydraulic cylinder are tested, including: acquiring the thrust value and rod chamber pressure of the tested hydraulic cylinder under the outward thrust condition at each sampling time interval (with a third sampling period as the time interval), or the tension value and rodless chamber pressure under the pullback condition; determining the outward load efficiency of the tested hydraulic cylinder at each sampling time based on the thrust value, the rodless chamber pressure, and the rod chamber pressure, or determining the pullback load efficiency of the tested hydraulic cylinder at each sampling time based on the tension value, the rod chamber pressure, and the rodless chamber pressure; if the outward load efficiency or the pullback load efficiency is greater than or equal to a preset efficiency, the tested hydraulic cylinder is determined to be in a normal state; if the outward thrust efficiency or the pullback load efficiency is greater than or equal to a preset efficiency, the tested hydraulic cylinder is determined to be in a normal state. If the push load efficiency or the pull-back load efficiency is less than the preset efficiency, then it is detected whether the stroke at the sampling time corresponding to the push load efficiency or the pull-back load efficiency is within the buffer zone of the tested cylinder; if the stroke at the sampling time corresponding to the push load efficiency or the pull-back load efficiency is not within the buffer zone of the tested cylinder, then the rod chamber pressure under the push condition or the rodless chamber pressure under the pull-back condition is compared with the allowable back pressure; if the rod chamber pressure under the push condition or the rodless chamber pressure under the pull-back condition is greater than the allowable back pressure, then it is determined that there is an output characteristic fault caused by excessive back pressure within the stroke corresponding to the sampling time.

2. The fault detection method according to claim 1, characterized in that, The crawling vibration detection of the tested hydraulic cylinder includes: Calculate the absolute value of the average speed difference of the tested cylinder within any two adjacent first sampling periods; Compare the absolute value of the average speed difference with the magnitude of the first error threshold; If the absolute value of the average speed difference is greater than the first error threshold, then it is determined that the tested cylinder has a crawling vibration fault in the adjacent first sampling period.

3. The fault detection method according to claim 2, characterized in that, The calculation of the absolute value of the average speed difference of the tested cylinder within any two adjacent first sampling periods includes: Collect the displacement value of the tested hydraulic cylinder at the previous moment and the displacement value at the current moment; Determine the first average speed of the tested hydraulic cylinder between the previous moment and the current moment; The displacement value of the tested hydraulic cylinder at the next moment is collected, and the second average velocity of the tested hydraulic cylinder between the current moment and the next moment is calculated. Calculate the absolute value of the difference between the first average speed and the second average speed; The previous time and the current time, as well as the current time and the next time, are all separated by the first sampling period.

4. The fault detection method according to claim 3, characterized in that, Also includes: If the absolute value of the average speed difference is less than or equal to the first error threshold, then it is determined whether the displacement value at the next moment has reached the travel limit. If the displacement value at the next moment reaches the stroke limit, then calculate the average, maximum and minimum values ​​of the speed of the tested cylinder in all first sampling periods; When the absolute value of the difference between the average value and the maximum value is less than the first error threshold, and the absolute value of the difference between the average value and the minimum value is less than the first error threshold, it is determined that the tested cylinder has no crawling vibration fault. If the displacement value at the next moment does not reach the travel limit, then the current moment is updated as the previous moment, the next moment is updated as the current moment, and the time interval between the next moment and the first sampling period is updated as the next moment.

5. The fault detection method according to claim 1, characterized in that, The vibration and noise detection of the tested hydraulic cylinder includes: The initial vibration value of the tested hydraulic cylinder was collected when it was not in operation. During the operation of the tested hydraulic cylinder, the real-time vibration value of the tested hydraulic cylinder is collected at a time interval of the second sampling period; If the absolute value of the difference between the real-time vibration value and the initial vibration value is greater than the second error threshold, then it is determined that the tested cylinder has a vibration and noise fault within the stroke corresponding to the real-time vibration value.

6. The fault detection method according to claim 1, characterized in that, Also includes: If the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pullback condition is less than or equal to the allowable back pressure, then it is determined that there is an output characteristic fault caused by mechanical jamming within the stroke corresponding to the sampling time.

7. The fault detection method according to any one of claims 1-6, characterized in that, The fault detection device includes: a test bench, a test equipment, a test cylinder, an off-center loading cylinder, a lifting cylinder, a tension cylinder, a fixed pin, and a movable support. One end of the test bench is fixed to the ground via the fixed pin, and the other end of the test bench is fixed to the ground via the movable bracket; the bottom of the auxiliary test cylinder is fixed to the test bench surface at the opposite end to the test cylinder, and the piston rod of the auxiliary test cylinder is mechanically connected to the test equipment; the piston rod of the offset loading cylinder is mechanically connected to the guide sleeve of the test cylinder; the bottom of the lifting cylinder is fixed to the ground, and the piston rod of the lifting cylinder is mechanically connected to the test bench; the bottom of the tension cylinder is fixed to the ground, and the piston rod of the tension cylinder is mechanically connected to the test bench. The bottom of the test cylinder is fixed to the test bench. The test equipment, the accompanying cylinder, the offset loading cylinder, the lifting cylinder, and the tension cylinder are used to adjust the fault detection device to the crawling vibration detection mode, the vibration and abnormal noise detection mode, and the output characteristic detection mode.

8. A fault detection device, characterized in that, include: The determination module is used to determine the fault detection type, which includes crawling vibration detection type, vibration and abnormal noise detection type, and output characteristic detection type; The creeping vibration detection module is used to adjust the fault detection device to the creeping vibration detection mode corresponding to the creeping vibration detection type, and to perform creeping vibration detection on the tested hydraulic cylinder. The vibration and noise detection module is used to adjust the fault detection device to the vibration and noise detection mode corresponding to the vibration and noise detection type, and to perform vibration and noise detection on the tested hydraulic cylinder. The output characteristic detection module is used to adjust the fault detection device to the output characteristic detection mode corresponding to the output characteristic detection type, and to perform output characteristic detection on the tested hydraulic cylinder. The output characteristics of the tested hydraulic cylinder are tested, including: acquiring the thrust value and rod chamber pressure of the tested hydraulic cylinder under the outward thrust condition at each sampling time interval (with a third sampling period as the time interval), or the tension value and rodless chamber pressure under the pullback condition; determining the outward load efficiency of the tested hydraulic cylinder at each sampling time based on the thrust value, the rodless chamber pressure, and the rod chamber pressure, or determining the pullback load efficiency of the tested hydraulic cylinder at each sampling time based on the tension value, the rod chamber pressure, and the rodless chamber pressure; if the outward load efficiency or the... If the pull-back load efficiency is greater than or equal to the preset efficiency, the tested cylinder is determined to be in normal condition. If the extrapolation load efficiency or the pull-back load efficiency is less than the preset efficiency, it is detected whether the stroke at the sampling time corresponding to the extrapolation load efficiency or the pull-back load efficiency is within the buffer zone of the tested cylinder. If the stroke at the sampling time corresponding to the extrapolation load efficiency or the pull-back load efficiency is not within the buffer zone of the tested cylinder, the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pull-back condition is compared with the allowable back pressure. If the rod chamber pressure under the extrapolation condition or the rodless chamber pressure under the pullback condition is greater than the allowable back pressure, then it is determined that there is an output characteristic fault caused by excessive back pressure within the stroke corresponding to the sampling time.

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