UAV hydraulic pump oil distribution plate and swash plate fault detection method and system

Abstract

The present invention provides a method and system for detecting faults in the oil distribution plate and swash plate of a hydraulic pump for an unmanned aerial vehicle (UAV), relating to the technical field of UAVs. The method comprises: obtaining frequency characteristic information of the hydraulic pump based on the operating speed and number of plungers of the hydraulic pump; constructing a fault detection parameter set and threshold values ​​corresponding to each fault detection parameter in the fault detection parameter set; obtaining power spectra of a normal hydraulic pump and a hydraulic pump to be tested during operation within a set time period and performing calculations to obtain energy data at each frequency multiplication value; calculating the energy data at each frequency multiplication value to obtain the numerical value corresponding to each fault detection parameter; and determining the fault detection result based on each numerical value and its corresponding threshold value. The present invention can improve the accuracy of fault detection of the oil distribution plate and swash plate components of a UAV hydraulic pump, significantly reduce fault detection time, realize onboard online real-time detection, and prevent major faults in the UAV hydraulic pump.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles (UAVs), and in particular to a method and system for detecting faults of an oil distribution plate and a swash plate of a hydraulic pump of an UAV. Background Art

[0002] The oil distribution plate and swash plate of the UAV hydraulic pump are core components. Due to the harsh working environment of the oil distribution plate and swash plate of the UAV hydraulic pump and the alternating load, they need to operate reliably and stably for a long time. In addition, the existing fault detection methods have large computational complexity, poor real-time performance, and low decision-making accuracy. They are only suitable for ground tests and research verification. There is no efficient and high-accuracy online real-time fault detection method that can be embedded in the hydraulic pump housing for flight. Therefore, it is impossible to predict possible accidents in advance during the flight of the UAV, and it is difficult to effectively prevent major faults. Summary of the Invention

[0003] The purpose of the present invention is to provide a method and system for detecting the oil distribution plate and swash plate faults of a UAV hydraulic pump, which greatly reduces the fault detection time, realizes airborne online real-time detection, can prevent major faults of the UAV hydraulic pump, and has high detection efficiency.

[0004] A method for detecting faults of an oil distribution plate and a swash plate of a hydraulic pump of a drone, comprising:

[0005] Obtain frequency characteristic information of the hydraulic pump based on the operating speed and number of plungers of the hydraulic pump; the frequency characteristic information includes a fundamental frequency value, a double frequency value, a triple frequency value, a quadruple frequency value, a quintuple frequency value, and a sextuple frequency value;

[0006] Constructing a fault detection parameter set and a threshold value corresponding to each fault detection parameter in the fault detection parameter set; the fault detection parameter set includes abnormal vibration parameters of the oil distribution plate and the swash plate, fault parameters of the oil distribution plate and the swash plate, main fault parameters of the swash plate, secondary fault parameters of the swash plate, main fault parameters of the oil distribution plate, and secondary fault parameters of the oil distribution plate;

[0007] Acquire a first vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump when the hydraulic pump is operating normally within a set time period; construct a first power spectrum based on the first vibration signal;

[0008] Performing calculation based on the frequency characteristic information and the first power spectrum to obtain first energy data at each frequency multiplication value;

[0009] Acquire a second vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump to be tested during operation within a set time period; construct a second power spectrum based on the second vibration signal;

[0010] Performing calculation based on the frequency characteristic information and the second power spectrum to obtain second energy data at each frequency multiplication value;

[0011] Calculating based on each of the first energy data and each of the second energy data to obtain a value corresponding to each of the fault detection parameters;

[0012] Performing a judgment based on each of the numerical values ​​and the corresponding threshold value to obtain a fault detection result;

[0013] The numerical calculation formula for the abnormal vibration parameters of the oil distribution plate and the swash plate is as follows:

[0014]

[0015] The numerical calculation formulas for the fault parameters of the oil distribution plate and the swash plate are as follows:

[0016]

[0017] The numerical calculation formula of the main parameters of the swash plate fault is as follows:

[0018]

[0019] The numerical calculation formula of the swash plate fault secondary parameter is as follows:

[0020]

[0021] The numerical calculation formula of the main parameters of the oil distribution plate fault is as follows:

[0022]

[0023] The numerical calculation formula of the oil distribution plate fault secondary parameter is as follows:

[0024]

[0025] Where: T1 is the value of the abnormal vibration parameter of the oil distribution plate and the swash plate, T2 is the value of the fault parameter of the oil distribution plate and the swash plate, T 3-1 is the value of the main parameter of the swash plate fault, T 3-2 is the value of the secondary parameter of the swash plate fault, T 4-1 is the value of the main parameter of the oil distribution plate fault, T 4-2 is the value of the secondary parameter of the oil distribution plate fault, EB1 is the second energy data at the fundamental frequency value, EB2 is the second energy data at the double frequency value, EB3 is the second energy data at the triple frequency value, EB4 is the second energy data at the quadruple frequency value, EB5 is the second energy data at the quintuple frequency value, EB6 is the second energy data at the sextuple frequency value, EA2 is the first energy data at the double frequency value, EA3 is the first energy data at the triple frequency value, EA4 is the first energy data at the quadruple frequency value, EB T =EB1+EB2+EB3+EB4+EB5+EB6.

[0026] Optionally, the judgment based on each of the numerical values ​​and each of the thresholds to obtain a fault detection result is specifically:

[0027] If the abnormal vibration parameters of the oil distribution plate and the swash plate are less than their corresponding thresholds, the hydraulic pump to be tested is normal; if the abnormal vibration parameters of the oil distribution plate and the swash plate are greater than or equal to their corresponding thresholds, the vibration of the oil distribution plate and the swash plate is abnormal.

[0028] When the oil distribution plate and the swash plate vibrate abnormally, the fault parameters of the oil distribution plate and the swash plate are judged. If the fault parameters of the oil distribution plate and the swash plate are greater than or equal to their corresponding thresholds, the oil distribution plate and the swash plate are both faulty. If the fault parameters of the oil distribution plate and the swash plate are less than their corresponding thresholds, the main fault parameter of the swash plate and the secondary fault parameter of the swash plate are judged.

[0029] If the swash plate fault main parameter is greater than or equal to its corresponding threshold value and the swash plate fault secondary parameter is less than or equal to its corresponding threshold value, the swash plate is faulty; if the swash plate fault main parameter is less than its corresponding threshold value or the swash plate fault secondary parameter is greater than its corresponding threshold value, the oil distribution plate fault main parameter and the oil distribution plate fault secondary parameter are judged;

[0030] If the main parameter of the oil distribution plate fault is greater than or equal to its corresponding threshold and the secondary parameter of the oil distribution plate fault is less than or equal to its corresponding threshold, the oil distribution plate is faulty; if the main parameter of the oil distribution plate fault is less than its corresponding threshold or the secondary parameter of the oil distribution plate fault is greater than its corresponding threshold, an unknown abnormality occurs in the hydraulic pump to be tested.

[0031] The fault detection results include the hydraulic pump to be tested being normal, both the oil distribution plate and the swash plate being faulty, the swash plate being faulty, the oil distribution plate being faulty, and an unknown abnormality occurring.

[0032] Optionally, obtaining the frequency characteristic information of the hydraulic pump based on the operating speed and the number of plungers of the hydraulic pump includes:

[0033] The fundamental frequency value of the hydraulic pump is obtained based on the operating speed and number of plungers of the hydraulic pump;

[0034] A double frequency value, a triple frequency value, a quadruple frequency value, a quintuple frequency value and a sextuple frequency value are obtained based on the fundamental frequency value.

[0035] Optionally, the calculation based on the frequency characteristic information and the first power spectrum to obtain the first energy data at each frequency multiplication value is specifically:

[0036] Performing calculation based on the double frequency value and the first power spectrum to obtain the first energy data at the double frequency value;

[0037] Performing calculation based on the triple frequency value and the first power spectrum to obtain the first energy data at the triple frequency value;

[0038] Calculation is performed based on the fourth frequency value and the first power spectrum to obtain the first energy data at the fourth frequency value.

[0039] Optionally, the first energy data at the double frequency value is calculated as follows:

[0040]

[0041] The calculation formula for the first energy data at the triple frequency value is as follows:

[0042]

[0043] The calculation formula for the first energy data at the quadruple frequency value is as follows:

[0044]

[0045] Where: AV 2i Represents the amplitude of the first power spectrum at the double frequency value of frequency i, AV 3i represents the amplitude of the first power spectrum at the frequency i position at the triple frequency value, AV 4i represents the amplitude of the first power spectrum at the fourth frequency value at frequency i, f2 represents the double frequency value, f3 represents the triple frequency value, and f4 represents the quadruple frequency value.

[0046] Optionally, the calculation based on the frequency characteristic information and the second power spectrum to obtain the second energy data at each frequency multiplication value is specifically:

[0047] Performing calculation based on the fundamental frequency value and the second power spectrum to obtain the second energy data at the fundamental frequency value;

[0048] Performing calculation based on the double frequency value and the second power spectrum to obtain the second energy data at the double frequency value;

[0049] Performing calculation based on the triple frequency value and the second power spectrum to obtain the second energy data at the triple frequency value;

[0050] Performing calculation based on the fourth frequency value and the second power spectrum to obtain the second energy data at the fourth frequency value;

[0051] Performing calculation based on the fifth frequency value and the second power spectrum to obtain the second energy data at the fifth frequency value;

[0052] Calculation is performed based on the sextuplicate frequency value and the second power spectrum to obtain the second energy data at the sextuplicate frequency value.

[0053] Optionally, the second energy data calculation formula at the fundamental frequency value is as follows:

[0054]

[0055] The calculation formula for the second energy data at the double frequency value is as follows:

[0056]

[0057] The calculation formula for the second energy data at the triple frequency value is as follows:

[0058]

[0059] The calculation formula for the second energy data at the quadruple frequency value is as follows:

[0060]

[0061] The calculation formula for the second energy data at the fifth frequency value is as follows:

[0062]

[0063] The calculation formula for the second energy data at the sixth frequency value is as follows:

[0064]

[0065] Where: BV 1i is the amplitude of the second power spectrum at the fundamental frequency value at frequency i, BV 2i BV is the amplitude of the second power spectrum at the frequency i position at the double frequency value, 3i BV is the amplitude of the second power spectrum at the frequency i position at the triple frequency value, 4i BV is the amplitude of the second power spectrum at the frequency i position at the fourth frequency value, 5i BV is the amplitude of the second power spectrum at the fifth frequency value at frequency i, 6i is the amplitude of the second power spectrum at the sixth frequency value at frequency i, f1 is the fundamental frequency value, f2 represents the second frequency value, f3 represents the third frequency value, f4 represents the fourth frequency value, f5 represents the fifth frequency value, and f6 represents the sixth frequency value.

[0066] The present invention also provides a UAV hydraulic pump oil distribution plate and swash plate fault detection system, comprising:

[0067] A frequency characteristic module is used to obtain frequency characteristic information of the hydraulic pump based on the operating speed and the number of plungers of the hydraulic pump; the frequency characteristic information includes a fundamental frequency value, a double frequency value, a triple frequency value, a quadruple frequency value, a quintuple frequency value, and a sextuple frequency value;

[0068] a parameter threshold module for constructing a fault detection parameter set and a threshold value corresponding to each fault detection parameter in the fault detection parameter set based on cognition-oriented construction; the fault detection parameter set includes abnormal vibration parameters of the oil distribution plate and the swash plate, fault parameters of the oil distribution plate and the swash plate, primary fault parameters of the swash plate, secondary fault parameters of the swash plate, primary fault parameters of the oil distribution plate, and secondary fault parameters of the oil distribution plate;

[0069] a first power module, configured to obtain a first vibration signal at a connection between the oil distribution plate and the swash plate when the hydraulic pump is operating normally within a set time period, and construct a first power spectrum based on the first vibration signal;

[0070] A first energy module is configured to perform calculation based on the frequency characteristic information and the first power spectrum to obtain first energy data at each frequency multiplication value;

[0071] a second power module, configured to obtain a second vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump to be tested during operation within a set time period, and to construct a second power spectrum based on the second vibration signal;

[0072] A second energy module is configured to perform calculation based on the frequency characteristic information and the second power spectrum to obtain second energy data at each frequency multiplication value;

[0073] a parameter calculation module, configured to calculate, based on each of the first energy data and each of the second energy data, a value corresponding to each of the fault detection parameters;

[0074] The numerical calculation formula for the abnormal vibration parameters of the oil distribution plate and the swash plate is as follows:

[0075]

[0076] The numerical calculation formulas for the fault parameters of the oil distribution plate and the swash plate are as follows:

[0077]

[0078] The numerical calculation formula of the main parameters of the swash plate fault is as follows:

[0079]

[0080] The numerical calculation formula of the swash plate fault secondary parameter is as follows:

[0081]

[0082] The numerical calculation formula of the main parameters of the oil distribution plate fault is as follows:

[0083]

[0084] The numerical calculation formula of the oil distribution plate fault secondary parameter is as follows:

[0085]

[0086] Where: T1 is the value of the abnormal vibration parameter of the oil distribution plate and the swash plate, T2 is the value of the fault parameter of the oil distribution plate and the swash plate, T 3-1 is the value of the main parameter of the swash plate fault, T 3-2 is the value of the secondary parameter of the swash plate fault, T 4-1 is the value of the main parameter of the oil distribution plate fault, T 4-2 is the value of the secondary parameter of the oil distribution plate fault, EB1 is the second energy data at the fundamental frequency value, EB2 is the second energy data at the double frequency value, EB3 is the second energy data at the triple frequency value, EB4 is the second energy data at the quadruple frequency value, EB5 is the second energy data at the quintuple frequency value, EB6 is the second energy data at the sextuple frequency value, EA2 is the first energy data at the double frequency value, EA3 is the first energy data at the triple frequency value, EA4 is the first energy data at the quadruple frequency value, EB T =EB1+EB2+EB3+EB4+EB5+EB6;

[0087] The fault detection module is used to make a judgment based on each of the numerical values ​​and the corresponding threshold values ​​to obtain a fault detection result.

[0088] The effects of the present invention are as follows:

[0089] The method and system for detecting the oil distribution plate and swash plate faults of the hydraulic pump of a UAV of the present invention can improve the accuracy of fault detection of the oil distribution plate and swash plate components of the hydraulic pump of a UAV, greatly reduce the fault detection time, and realize airborne online real-time detection. Moreover, by introducing the concept of oriented cognition, the perception of the status of the oil distribution plate and swash plate components of the hydraulic pump of a UAV is enhanced, and the degradation of the system status can be more accurately identified, and major faults of the hydraulic pump of the UAV can be prevented. The detection efficiency is high and the system is simple and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 This is a flow chart of the method for detecting faults of the oil distribution plate and swash plate of a hydraulic pump of a UAV according to the present invention;

[0091] Figure 2 This is a structural diagram of the UAV hydraulic pump oil distribution plate and swash plate fault detection system of the present invention;

[0092] Figure 3 It is a fault detection flow chart of the present invention;

[0093] Figure 4 is a schematic diagram of a first power spectrum diagram of a first example;

[0094] Figure 5 is a schematic diagram of a second power spectrum diagram of the first example;

[0095] Figure 6 is a schematic diagram of a first power spectrum diagram of a second example;

[0096] Figure 7 is a schematic diagram of the second power spectrum diagram of the second example.

[0097] In the figure: 1. Frequency characteristic module; 2. Parameter threshold module; 3. First power module; 4. First energy module; 5. Second power module; 6. Second energy module; 7. Parameter calculation module; 8. Fault detection module. DETAILED DESCRIPTION

[0098] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0099] Figure 1 This is a flow chart of the method for detecting faults of the oil distribution plate and swash plate of the hydraulic pump of the UAV of the present invention. Figure 1 As shown, the present invention provides a method for detecting faults of an oil distribution plate and a swash plate of a hydraulic pump of a UAV, comprising:

[0100] Step S1 : obtaining frequency characteristic information of the hydraulic pump based on the operating speed and number of plungers of the hydraulic pump.

[0101] In this embodiment, the frequency characteristic information includes a fundamental frequency value, a double frequency value, a triple frequency value, a quadruple frequency value, a quintuple frequency value, and a sextuple frequency value.

[0102] First, the fundamental frequency of the hydraulic pump is obtained based on the operating speed and number of plungers of the hydraulic pump. The fundamental frequency calculation formula is as follows:

[0103] f1=operating speed of hydraulic pump (r / s)×number of plungers;

[0104] Where: f1 is the fundamental frequency value.

[0105] Based on the fundamental frequency value, the double frequency value, triple frequency value, quadruple frequency value, quintuple frequency value and sextuple frequency value are obtained.

[0106] The calculation formula is as follows:

[0107] f2=2×f1;

[0108] f3=3×f1;

[0109] f4=4×f1;

[0110] f5=5×f1;

[0111] f6=6×f1;

[0112] Where: f2 represents the double frequency value, f3 represents the triple frequency value, f4 represents the quadruple frequency value, f5 represents the quintuple frequency value, and f6 represents the sextuple frequency value.

[0113] Step S2: construct a fault detection parameter set and a threshold value corresponding to each fault detection parameter in the fault detection parameter set.

[0114] In this embodiment, the fault detection parameter set includes the oil distribution plate and swash plate vibration abnormality parameters, the oil distribution plate and swash plate fault parameters, the swash plate fault main parameters, the swash plate fault secondary parameters, the oil distribution plate fault main parameters and the oil distribution plate fault secondary parameters. Each threshold value is selected based on the structural characteristics, materials, processes and usage requirements of the oil distribution plate and swash plate of the hydraulic pump to be tested. Y1 represents the threshold value corresponding to the oil distribution plate and swash plate vibration abnormality parameters, Y2 represents the threshold value corresponding to the oil distribution plate and swash plate fault parameters, and Y 3-1 Indicates the threshold value corresponding to the main parameter of the swash plate fault, Y 3-2 Indicates the threshold value corresponding to the secondary parameter of the swash plate fault, Y 4-1 Indicates the threshold value corresponding to the main parameter of the oil distribution plate fault, Y 4-2 Indicates the threshold corresponding to the secondary parameter of the oil distribution plate fault.

[0115] Step S3: obtaining a first vibration signal at the connection between the oil distribution plate and the swash plate when the hydraulic pump is operating normally within a set time period; and constructing a first power spectrum based on the first vibration signal.

[0116] In this embodiment, a vibration acceleration sensor installed at the junction of the oil distribution plate and swash plate of a normal hydraulic pump acquires a first vibration signal, calculates its vibration power spectrum, and plots it to obtain a first power spectrum. The abscissa of the first power spectrum represents frequency, and the ordinate represents power amplitude. The set time is selected based on actual needs; in this embodiment, 1 second is selected.

[0117] Step S4: performing calculation based on the frequency characteristic information and the first power spectrum to obtain first energy data at each frequency multiplication value.

[0118] Specifically, step S4 includes:

[0119] Step S41: Calculate based on the double frequency value and the first power spectrum to obtain first energy data at the double frequency. The calculation formula is as follows:

[0120]

[0121] Step S42: Calculate based on the triple frequency value and the first power spectrum to obtain first energy data at the triple frequency. The calculation formula is as follows:

[0122]

[0123] Step S43: Calculate based on the quadruple frequency value and the first power spectrum to obtain first energy data at the quadruple frequency. The calculation formula is as follows:

[0124]

[0125] Where: EA2 is the first energy data at double frequency, EA3 is the first energy data at triple frequency, EA4 is the first energy data at quadruple frequency, AV 2i represents the amplitude of the first power spectrum at the frequency i near the double frequency, AV 3i represents the amplitude of the first power spectrum at frequency i near the triple frequency, AV 4i Represents the amplitude of the first power spectrum at frequency i near the fourth harmonic.

[0126] Step S5: Acquire a second vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump under test during operation within a set time period; construct a second power spectrum based on the second vibration signal. For details, see step S3.

[0127] Step S6: performing calculation based on the frequency characteristic information and the second power spectrum to obtain second energy data at each frequency multiplication value.

[0128] Furthermore, step S6 includes:

[0129] Step S61: Calculate based on the fundamental frequency value and the second power spectrum to obtain the second energy data at the fundamental frequency. The calculation formula is as follows:

[0130]

[0131] Step S62: Calculate based on the double frequency value and the second power spectrum to obtain the second energy data at the double frequency. The calculation formula is as follows:

[0132]

[0133] Step S63: Calculate based on the triple frequency value and the second power spectrum to obtain the second energy data at the triple frequency. The calculation formula is as follows:

[0134]

[0135] Step S64: Calculate based on the quadruple frequency value and the second power spectrum to obtain the second energy data at the quadruple frequency. The calculation formula is as follows:

[0136]

[0137] Step S65: Calculate based on the fifth harmonic value and the second power spectrum to obtain the second energy data at the fifth harmonic. The calculation formula is as follows:

[0138]

[0139] Step S66: Calculate based on the sixth harmonic value and the second power spectrum to obtain the second energy data at the sixth harmonic. The calculation formula is as follows:

[0140]

[0141] Where: EB1 is the second energy data at the fundamental frequency, EB2 is the second energy data at the double frequency, EB3 is the second energy data at the triple frequency, EB4 is the second energy data at the quadruple frequency, EB5 is the second energy data at the quintuple frequency, EB6 is the second energy data at the sextuple frequency, BV 1i is the amplitude of the second power spectrum at frequency i near the fundamental frequency, BV 2i is the amplitude of the second power spectrum at frequency i near the double frequency, BV 3i is the amplitude of the second power spectrum at frequency i near the triple frequency, BV 4i is the amplitude of the second power spectrum at frequency i near the fourth harmonic, BV 5i BV is the amplitude of the second power spectrum at frequency i near the fifth harmonic, 6i is the amplitude of the second power spectrum at frequency i near the sixth harmonic.

[0142] Step S7: Calculate based on each first energy data and each second energy data to obtain a value corresponding to each fault detection parameter.

[0143] Preferably, the numerical calculation formula for the abnormal vibration parameters of the oil distribution plate and the swash plate is as follows:

[0144]

[0145] The numerical calculation formula for the fault parameters of the oil distribution plate and the swash plate is as follows:

[0146]

[0147] The numerical calculation formula of the main parameters of the swash plate fault is as follows:

[0148]

[0149] The numerical calculation formula of the secondary parameter of the swash plate fault is as follows:

[0150]

[0151] The numerical calculation formula for the main parameters of the oil distribution plate fault is as follows:

[0152]

[0153] The numerical calculation formula of the secondary parameter of the oil distribution plate fault is as follows:

[0154]

[0155] Where: T1 is the value of the abnormal vibration parameter of the oil distribution plate and the swash plate, T2 is the value of the fault parameter of the oil distribution plate and the swash plate, T 3-1 is the value of the main parameter of the swash plate fault, T 3-2 is the value of the secondary parameter of the swash plate fault, T 4-1 is the value of the main parameter of the oil distribution plate fault, T 4-2 is the value of the secondary parameter of the oil distribution plate failure, EB T =EB1+EB2+EB3+EB4+EB5+EB6.

[0156] Step S8: Make a judgment based on each value and its corresponding threshold value to obtain a fault detection result.

[0157] Specifically, if Figure 3 As shown, if the vibration abnormality parameters of the oil distribution plate and the swash plate are less than their corresponding thresholds, the hydraulic pump to be tested is normal; if the vibration abnormality parameters of the oil distribution plate and the swash plate are greater than or equal to their corresponding thresholds, the vibration of the oil distribution plate and the swash plate is abnormal.

[0158] When the oil distribution plate and the swash plate vibrate abnormally, the fault parameters of the oil distribution plate and the swash plate are judged. If the fault parameters of the oil distribution plate and the swash plate are greater than or equal to their corresponding thresholds, the oil distribution plate and the swash plate are both faulty. If the fault parameters of the oil distribution plate and the swash plate are less than their corresponding thresholds, the main fault parameters and the secondary fault parameters of the swash plate are judged.

[0159] If the swash plate fault main parameter is greater than or equal to its corresponding threshold and the swash plate fault secondary parameter is less than or equal to its corresponding threshold, the swash plate is faulty; if the swash plate fault main parameter is less than its corresponding threshold or the swash plate fault secondary parameter is greater than its corresponding threshold, the oil distribution plate fault main parameter and the oil distribution plate fault secondary parameter are judged;

[0160] If the main parameter of the oil distribution plate fault is greater than or equal to its corresponding threshold and the secondary parameter of the oil distribution plate fault is less than or equal to its corresponding threshold, the oil distribution plate is faulty; if the main parameter of the oil distribution plate fault is less than its corresponding threshold or the secondary parameter of the oil distribution plate fault is greater than its corresponding threshold, an unknown abnormality occurs in the hydraulic pump to be tested.

[0161] The fault detection results include the hydraulic pump to be tested is normal, both the oil distribution plate and the swash plate are faulty, the swash plate is faulty, the oil distribution plate is faulty, and an unknown abnormality occurs.

[0162] When the fault detection result is any one or more of the following: failure of the oil distribution plate and the swash plate, failure of the swash plate, failure of the oil distribution plate, and an unknown abnormality, the hydraulic pump to be tested shall be disassembled and the fault shall be repaired.

[0163] Taking a hydraulic pump with an operating speed of 1500r / min and 8 plungers as an example, the calculation is as follows:

[0164] Fundamental frequency value = 1500 / 60×8 = 200Hz, represented by f1.

[0165] The double frequency value = 2×200 = 400Hz, represented by f2.

[0166] The triple frequency value = 3×200 = 600Hz is represented by f3.

[0167] The fourth frequency value = 4×200 = 800Hz, represented by f4.

[0168] The fifth frequency value = 5×200 = 1000Hz is represented by f5.

[0169] The sixth frequency value = 6×200 = 1200Hz is represented by f6.

[0170] Obtain the first vibration signal at the connection between the oil distribution plate and the swash plate when the hydraulic pump is working normally, and calculate the amplitude of the power at different frequencies. The first power spectrum obtained is as follows: Figure 4 shown.

[0171] The first energy data at the double frequency value is calculated as follows:

[0172]

[0173] The first energy data at the triple frequency value is calculated as follows:

[0174]

[0175] The first energy data at the fourth harmonic value is calculated as follows:

[0176]

[0177] Obtain the second vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump under test when it is working, and calculate the amplitude of the power at different frequencies. The obtained second power spectrum is as follows: Figure 5 shown.

[0178] The second energy data at the fundamental frequency value is calculated as follows:

[0179]

[0180] The second energy data at the double frequency value is calculated as follows:

[0181]

[0182] The second energy data at the triple frequency value is calculated as follows:

[0183]

[0184] The second energy data at the fourth harmonic value is calculated as follows:

[0185]

[0186] The second energy data at the fifth harmonic value is calculated as follows:

[0187]

[0188] The second energy data at the sixth frequency value is calculated as follows:

[0189]

[0190] EB T =EB1+EB2+EB3+EB4+EB5+EB6

[0191] =3.04918+1.346399+3.635306+2.890223+3.810166+2.460654=17.191928.

[0192] The numerical calculation of the abnormal vibration parameters of the oil distribution plate and the swash plate is as follows:

[0193]

[0194] The numerical calculation of the main parameters of the swash plate fault is as follows:

[0195]

[0196] The numerical calculation of the secondary parameters of the swash plate fault is as follows:

[0197]

[0198] Swash plate failure detection auxiliary indicator T 3-2 The calculation is as follows:

[0199]

[0200] The numerical calculation of the main parameters of the oil distribution plate fault is as follows:

[0201]

[0202] The numerical calculation of the secondary parameter of the oil distribution plate fault is as follows:

[0203]

[0204] In this embodiment, the threshold values ​​corresponding to the fault detection parameters are determined as follows: Y1=0.40, Y2=0.30, Y 3-1 =0.15, Y3-2 =0.80, Y 4-1 =0.50, Y 4-2 =0.70.

[0205] Since T1=0.46713114 and Y1=0.40, T1≥Y1 exists, indicating that abnormal vibration of the oil distribution plate and the swash plate occurs at this time.

[0206] Since T2=0.532869, Y2=0.30, T2≥Y2, indicating that both the oil distribution plate and the swash plate are faulty. The hydraulic pump to be tested should be disassembled and the fault should be repaired.

[0207] Taking a hydraulic pump with an operating speed of 2400r / min and 11 plungers as an example, the calculation is as follows:

[0208] Fundamental frequency value = 2400 / 60×11 = 440Hz, represented by f1.

[0209] The double frequency value = 2×440 = 880Hz, represented by f2.

[0210] The triple frequency value = 3×440 = 1320Hz is represented by f3.

[0211] The fourth frequency value = 4×440 = 1760Hz, represented by f4.

[0212] The fifth frequency value = 5×440 = 2200Hz is represented by f5.

[0213] The sixth frequency value = 6×440 = 2640Hz is represented by f6.

[0214] Obtain the first vibration signal at the connection between the oil distribution plate and the swash plate when the hydraulic pump is working normally, and calculate the amplitude of the power at different frequencies. The first power spectrum obtained is as follows: Figure 6 shown.

[0215] The first energy data at the double frequency value is calculated as follows:

[0216]

[0217] The first energy data at the triple frequency value is calculated as follows:

[0218]

[0219] The first energy data at the fourth harmonic value is calculated as follows:

[0220]

[0221] Obtain the second vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump under test when it is working, and calculate the amplitude of the power at different frequencies. The obtained second power spectrum is as follows: Figure 7 shown.

[0222] The second energy data at the fundamental frequency value is calculated as follows:

[0223]

[0224] The second energy data at the double frequency value is calculated as follows:

[0225]

[0226] The second energy data at the triple frequency value is calculated as follows:

[0227]

[0228] The second energy data at the fourth harmonic value is calculated as follows:

[0229]

[0230] The second energy data at the fifth harmonic value is calculated as follows:

[0231]

[0232] The second energy data at the sixth frequency value is calculated as follows:

[0233]

[0234] EB T =EB1+EB2+EB3+EB4+EB5+EB6=3.366938+3.412321+3.596237+2.65302+2.818502+4.463709=20.310727.

[0235] The numerical calculation of the abnormal vibration parameters of the oil distribution plate and the swash plate is as follows:

[0236]

[0237] The numerical calculation of the main parameters of the swash plate fault is as follows:

[0238]

[0239] The numerical calculation of the secondary parameters of the swash plate fault is as follows:

[0240]

[0241] Swash plate failure detection auxiliary indicator T 3-2 The calculation is as follows:

[0242]

[0243] The numerical calculation of the main parameters of the oil distribution plate fault is as follows:

[0244]

[0245] The numerical calculation of the secondary parameter of the oil distribution plate fault is as follows:

[0246]

[0247] In this embodiment, the threshold values ​​corresponding to the fault detection parameters are determined as follows: Y1=0.50, Y2=0.60, Y 3-1 =0.55, Y 3-2 =1.0, Y 4-1 =0.25, Y 4-2 =1.20.

[0248] Since T1=0.51083824 and Y1=0.50, T1≥Y1 exists, indicating that abnormal vibration of the oil distribution plate and the swash plate occurs at this time.

[0249] Since T2=0.48916176 and Y2=0.60, T2≥Y2 does not exist, which means that the oil distribution plate and the swash plate are not both faulty at this time.

[0250] The main and secondary parameters of the swash plate fault are judged. 3-1 =0.16577142 and T 3-2 =0.16903702, does not meet T 3-1 ≥Y 3-1 And T 3-2 ≤Y 3-2 Condition, indicating that the swash plate is normal.

[0251] The main and secondary parameters of the oil distribution plate fault are judged. 4-1 =0.29639303 and T 4-2 =1.14849059, there exists T 4-1 ≥Y 4-1 And T 4-2 <Y 4-2 , indicating that the oil distribution plate failure has occurred. The hydraulic pump to be tested should be disassembled and the failure should be repaired.

[0252] Figure 2 This is a structural diagram of the hydraulic pump oil distribution plate and swash plate fault detection system for drones of the present invention. Figure 2As shown, the present invention provides a UAV hydraulic pump oil distribution plate and swash plate fault detection system, including: a frequency characteristic module 1, a parameter threshold module 2, a first power module 3, a first energy module 4, a second power module 5, a second energy module 6, a parameter calculation module 7 and a fault detection module 8.

[0253] The frequency characteristic module 1 is used to obtain frequency characteristic information of the hydraulic pump based on the operating speed and the number of plungers of the hydraulic pump.

[0254] In this embodiment, the frequency characteristic information includes a fundamental frequency value, a double frequency value, a triple frequency value, a quadruple frequency value, a quintuple frequency value, and a sextuple frequency value.

[0255] The parameter threshold module 2 is used to construct a fault detection parameter set and a threshold value corresponding to each fault detection parameter in the fault detection parameter set based on cognition.

[0256] In this embodiment, the fault detection parameter set includes oil distribution plate and swash plate vibration abnormality parameters, oil distribution plate and swash plate fault parameters, swash plate fault main parameters, swash plate fault secondary parameters, oil distribution plate fault main parameters and oil distribution plate fault secondary parameters.

[0257] The first power module 3 is used to obtain a first vibration signal at the connection between the oil distribution plate and the swash plate when the hydraulic pump is working normally within a set time period, and to construct a first power spectrum based on the first vibration signal.

[0258] The first energy module 7 is used to perform calculations based on the frequency characteristic information and the first power spectrum to obtain first energy data at each frequency multiplication value.

[0259] The second power module 8 is used to obtain a second vibration signal at the connection between the oil distribution plate and the swash plate when the hydraulic pump to be tested is working within a set time period, and construct a second power spectrum based on the second vibration signal.

[0260] The second energy module 9 is used to perform calculations based on the frequency characteristic information and the second power spectrum to obtain second energy data at each frequency multiplication value.

[0261] The parameter calculation module 7 is used to calculate the values ​​corresponding to the fault detection parameters based on the first energy data and the second energy data.

[0262] The numerical calculation formula for the abnormal vibration parameters of the oil distribution plate and the swash plate is as follows:

[0263]

[0264] The numerical calculation formula for the fault parameters of the oil distribution plate and the swash plate is as follows:

[0265]

[0266] The numerical calculation formula of the main parameters of the swash plate fault is as follows:

[0267]

[0268] The numerical calculation formula of the secondary parameter of the swash plate fault is as follows:

[0269]

[0270] The numerical calculation formula for the main parameters of the oil distribution plate fault is as follows:

[0271]

[0272] The numerical calculation formula of the secondary parameter of the oil distribution plate fault is as follows:

[0273]

[0274] Where: T1 is the value of the abnormal vibration parameter of the oil distribution plate and the swash plate, T2 is the value of the fault parameter of the oil distribution plate and the swash plate, T 3-1 is the value of the main parameter of the swash plate fault, T 3-2 is the value of the secondary parameter of the swash plate fault, T 4-1 is the value of the main parameter of the oil distribution plate fault, T 4-2 is the value of the secondary parameter of the oil distribution plate fault, EB1 is the second energy data at the fundamental frequency value, EB2 is the second energy data at the double frequency value, EB3 is the second energy data at the triple frequency value, EB4 is the second energy data at the quadruple frequency value, EB5 is the second energy data at the quintuple frequency value, EB6 is the second energy data at the sextuple frequency value, EA2 is the first energy data at the double frequency value, EA3 is the first energy data at the triple frequency value, EA4 is the first energy data at the quadruple frequency value, EB T =EB1+EB2+EB3+EB4+EB5+EB6

[0275] The fault detection module 8 is used to make judgments based on each value and its corresponding threshold value to obtain a fault detection result.

[0276] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0277] The above embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A method for detecting faults of the oil distribution plate and swash plate of a UAV hydraulic pump, characterized in that: It includes: The frequency characteristic information of the hydraulic pump is obtained based on the working speed and number of plungers of the hydraulic pump; The frequency characteristic information includes a fundamental frequency value, a double frequency value, a triple frequency value, a quadruple frequency value, a quintuple frequency value, and a sextuple frequency value; Constructing a fault detection parameter set and a threshold value corresponding to each fault detection parameter in the fault detection parameter set; the fault detection parameter set includes abnormal vibration parameters of the oil distribution plate and the swash plate, fault parameters of the oil distribution plate and the swash plate, main fault parameters of the swash plate, secondary fault parameters of the swash plate, main fault parameters of the oil distribution plate, and secondary fault parameters of the oil distribution plate; Acquire a first vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump when the hydraulic pump is operating normally within a set time period; construct a first power spectrum based on the first vibration signal; Performing calculation based on the frequency characteristic information and the first power spectrum to obtain first energy data at each frequency multiplication value; Acquire a second vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump to be tested during operation within a set time period; construct a second power spectrum based on the second vibration signal; Performing calculation based on the frequency characteristic information and the second power spectrum to obtain second energy data at each frequency multiplication value; Calculating based on each of the first energy data and each of the second energy data to obtain a value corresponding to each of the fault detection parameters; The numerical calculation formula for the abnormal vibration parameters of the oil distribution plate and the swash plate is as follows: The numerical calculation formulas for the fault parameters of the oil distribution plate and the swash plate are as follows: The numerical calculation formula of the main parameters of the swash plate fault is as follows: The numerical calculation formula of the swash plate fault secondary parameter is as follows: The numerical calculation formula of the main parameters of the oil distribution plate fault is as follows: The numerical calculation formula of the oil distribution plate fault secondary parameter is as follows: Where: T1 is the value of the abnormal vibration parameter of the oil distribution plate and the swash plate, T2 is the value of the fault parameter of the oil distribution plate and the swash plate, T 3-1 is the value of the main parameter of the swash plate fault, T 3-2 is the value of the secondary parameter of the swash plate fault, T 4-1 is the value of the main parameter of the oil distribution plate fault, T 4-2 is the value of the secondary parameter of the oil distribution plate fault, EB1 is the second energy data at the fundamental frequency value, EB2 is the second energy data at the double frequency value, EB3 is the second energy data at the triple frequency value, EB4 is the second energy data at the quadruple frequency value, EB5 is the second energy data at the quintuple frequency value, EB6 is the second energy data at the sextuple frequency value, EA2 is the first energy data at the double frequency value, EA3 is the first energy data at the triple frequency value, EA4 is the first energy data at the quadruple frequency value, EB T =EB1+EB2+EB3+EB4+EB5+EB6; Based on the values ​​and the corresponding thresholds, a fault detection result is obtained, specifically: If the vibration abnormality parameters of the oil distribution plate and the swash plate are less than their corresponding threshold values, the hydraulic pump to be tested is normal; if the vibration abnormality parameters of the oil distribution plate and the swash plate are greater than or equal to their corresponding threshold values, the vibration of the oil distribution plate and the swash plate is abnormal; When the oil distribution plate and the swash plate vibrate abnormally, the fault parameters of the oil distribution plate and the swash plate are judged. If the fault parameters of the oil distribution plate and the swash plate are greater than or equal to their corresponding thresholds, the oil distribution plate and the swash plate are both faulty. If the fault parameters of the oil distribution plate and the swash plate are less than their corresponding thresholds, the main fault parameter of the swash plate and the secondary fault parameter of the swash plate are judged. If the swash plate fault main parameter is greater than or equal to its corresponding threshold value and the swash plate fault secondary parameter is less than or equal to its corresponding threshold value, the swash plate is faulty; if the swash plate fault main parameter is less than its corresponding threshold value or the swash plate fault secondary parameter is greater than its corresponding threshold value, the oil distribution plate fault main parameter and the oil distribution plate fault secondary parameter are judged; If the main parameter of the oil distribution plate fault is greater than or equal to its corresponding threshold value and the secondary parameter of the oil distribution plate fault is less than or equal to its corresponding threshold value, the oil distribution plate is faulty; if the main parameter of the oil distribution plate fault is less than its corresponding threshold value or the secondary parameter of the oil distribution plate fault is greater than its corresponding threshold value, an unknown abnormality occurs in the hydraulic pump to be tested; The fault detection results include the hydraulic pump to be tested being normal, both the oil distribution plate and the swash plate being faulty, the swash plate being faulty, the oil distribution plate being faulty, and an unknown abnormality occurring.

2. The method for detecting faults of the oil distribution plate and swash plate of a UAV hydraulic pump according to claim 1, characterized in that: The frequency characteristic information of the hydraulic pump is obtained based on the operating speed and the number of plungers of the hydraulic pump, including: The fundamental frequency value of the hydraulic pump is obtained based on the operating speed and number of plungers of the hydraulic pump; A double frequency value, a triple frequency value, a quadruple frequency value, a quintuple frequency value and a sextuple frequency value are obtained based on the fundamental frequency value.

3. The method for detecting failures of the oil distribution plate and swash plate of a UAV hydraulic pump according to claim 1, characterized in that: The calculation based on the frequency characteristic information and the first power spectrum is performed to obtain the first energy data at each frequency multiplication value, specifically: Performing calculation based on the double frequency value and the first power spectrum to obtain the first energy data at the double frequency value; Performing calculation based on the triple frequency value and the first power spectrum to obtain the first energy data at the triple frequency value; Calculation is performed based on the fourth frequency value and the first power spectrum to obtain the first energy data at the fourth frequency value.

4. The method for detecting failures of the oil distribution plate and swash plate of a UAV hydraulic pump according to claim 3, characterized in that: The calculation formula for the first energy data at the double frequency value is as follows: The calculation formula for the first energy data at the triple frequency value is as follows: The calculation formula for the first energy data at the quadruple frequency value is as follows: Where: AV 2i Represents the amplitude of the first power spectrum at the double frequency value of frequency i, AV 3i represents the amplitude of the first power spectrum at the frequency i position at the triple frequency value, AV 4i represents the amplitude of the first power spectrum at the fourth frequency value at frequency i, f2 represents the double frequency value, f3 represents the triple frequency value, and f4 represents the quadruple frequency value.

5. The method for detecting failures of the oil distribution plate and swash plate of a UAV hydraulic pump according to claim 1, characterized in that: The calculation based on the frequency characteristic information and the second power spectrum is performed to obtain the second energy data at each frequency multiplication value, specifically: Performing calculation based on the fundamental frequency value and the second power spectrum to obtain the second energy data at the fundamental frequency value; Performing calculation based on the double frequency value and the second power spectrum to obtain the second energy data at the double frequency value; Performing calculation based on the triple frequency value and the second power spectrum to obtain the second energy data at the triple frequency value; Performing calculation based on the fourth frequency value and the second power spectrum to obtain the second energy data at the fourth frequency value; Performing calculation based on the fifth frequency value and the second power spectrum to obtain the second energy data at the fifth frequency value; Calculation is performed based on the sextuplicate frequency value and the second power spectrum to obtain the second energy data at the sextuplicate frequency value.

6. The method for detecting failures of the oil distribution plate and swash plate of a UAV hydraulic pump according to claim 5, characterized in that: The calculation formula for the second energy data at the fundamental frequency value is as follows: The calculation formula for the second energy data at the double frequency value is as follows: The calculation formula for the second energy data at the triple frequency value is as follows: The calculation formula for the second energy data at the quadruple frequency value is as follows: The calculation formula for the second energy data at the fifth frequency value is as follows: The calculation formula for the second energy data at the sixth frequency value is as follows: Where: BV 1i is the amplitude of the second power spectrum at the fundamental frequency value at frequency i, BV 2i BV is the amplitude of the second power spectrum at the frequency i position at the double frequency value, 3i BV is the amplitude of the second power spectrum at the frequency i position at the triple frequency value, 4i BV is the amplitude of the second power spectrum at the frequency i position at the fourth frequency value, 5i BV is the amplitude of the second power spectrum at the fifth frequency value at frequency i, 6i is the amplitude of the second power spectrum at the sixth frequency value at frequency i, f1 is the fundamental frequency value, f2 represents the second frequency value, f3 represents the third frequency value, f4 represents the fourth frequency value, f5 represents the fifth frequency value, and f6 represents the sixth frequency value.

7. A UAV hydraulic pump oil distribution plate and swash plate fault detection system, characterized in that: It includes: A frequency characteristic module is used to obtain frequency characteristic information of the hydraulic pump based on the operating speed and number of plungers of the hydraulic pump; The frequency characteristic information includes a fundamental frequency value, a double frequency value, a triple frequency value, a quadruple frequency value, a quintuple frequency value, and a sextuple frequency value; A parameter threshold module, configured to construct a fault detection parameter set and a threshold value corresponding to each fault detection parameter in the fault detection parameter set based on cognition-oriented construction; The fault detection parameter set includes abnormal vibration parameters of the oil distribution plate and the swash plate, fault parameters of the oil distribution plate and the swash plate, main fault parameters of the swash plate, secondary fault parameters of the swash plate, main fault parameters of the oil distribution plate and secondary fault parameters of the oil distribution plate; a first power module, configured to obtain a first vibration signal at a connection between the oil distribution plate and the swash plate when the hydraulic pump is operating normally within a set time period, and construct a first power spectrum based on the first vibration signal; A first energy module is configured to perform calculation based on the frequency characteristic information and the first power spectrum to obtain first energy data at each frequency multiplication value; a second power module, configured to obtain a second vibration signal at the connection between the oil distribution plate and the swash plate of the hydraulic pump to be tested during operation within a set time period, and to construct a second power spectrum based on the second vibration signal; A second energy module is configured to perform calculation based on the frequency characteristic information and the second power spectrum to obtain second energy data at each frequency multiplication value; a parameter calculation module, configured to calculate, based on each of the first energy data and each of the second energy data, a value corresponding to each of the fault detection parameters; The numerical calculation formula for the abnormal vibration parameters of the oil distribution plate and the swash plate is as follows: The numerical calculation formulas for the fault parameters of the oil distribution plate and the swash plate are as follows: The numerical calculation formula of the main parameters of the swash plate fault is as follows: The numerical calculation formula of the swash plate fault secondary parameter is as follows: The numerical calculation formula of the main parameters of the oil distribution plate fault is as follows: The numerical calculation formula of the oil distribution plate fault secondary parameter is as follows: Where: T1 is the value of the abnormal vibration parameter of the oil distribution plate and the swash plate, T2 is the value of the fault parameter of the oil distribution plate and the swash plate, T 3-1 is the value of the main parameter of the swash plate fault, T 3-2 is the value of the secondary parameter of the swash plate fault, T 4-1 is the value of the main parameter of the oil distribution plate fault, T 4-2 is the value of the secondary parameter of the oil distribution plate fault, EB1 is the second energy data at the fundamental frequency value, EB2 is the second energy data at the double frequency value, EB3 is the second energy data at the triple frequency value, EB4 is the second energy data at the quadruple frequency value, EB5 is the second energy data at the quintuple frequency value, EB6 is the second energy data at the sextuple frequency value, EA2 is the first energy data at the double frequency value, EA3 is the first energy data at the triple frequency value, EA4 is the first energy data at the quadruple frequency value, EB T =EB1+EB2+EB3+EB4+EB5+EB6; The fault detection module is used to make a judgment based on each of the numerical values ​​and the corresponding threshold values ​​to obtain a fault detection result, specifically: If the vibration abnormality parameters of the oil distribution plate and the swash plate are less than their corresponding threshold values, the hydraulic pump to be tested is normal; if the vibration abnormality parameters of the oil distribution plate and the swash plate are greater than or equal to their corresponding threshold values, the vibration of the oil distribution plate and the swash plate is abnormal; When the oil distribution plate and the swash plate vibrate abnormally, the fault parameters of the oil distribution plate and the swash plate are judged. If the fault parameters of the oil distribution plate and the swash plate are greater than or equal to their corresponding thresholds, the oil distribution plate and the swash plate are both faulty. If the fault parameters of the oil distribution plate and the swash plate are less than their corresponding thresholds, the main fault parameter of the swash plate and the secondary fault parameter of the swash plate are judged. If the swash plate fault main parameter is greater than or equal to its corresponding threshold value and the swash plate fault secondary parameter is less than or equal to its corresponding threshold value, the swash plate is faulty; if the swash plate fault main parameter is less than its corresponding threshold value or the swash plate fault secondary parameter is greater than its corresponding threshold value, the oil distribution plate fault main parameter and the oil distribution plate fault secondary parameter are judged; If the main parameter of the oil distribution plate fault is greater than or equal to its corresponding threshold value and the secondary parameter of the oil distribution plate fault is less than or equal to its corresponding threshold value, the oil distribution plate is faulty; if the main parameter of the oil distribution plate fault is less than its corresponding threshold value or the secondary parameter of the oil distribution plate fault is greater than its corresponding threshold value, an unknown abnormality occurs in the hydraulic pump to be tested; The fault detection results include the hydraulic pump to be tested being normal, both the oil distribution plate and the swash plate being faulty, the swash plate being faulty, the oil distribution plate being faulty, and an unknown abnormality occurring.

Images