Underwater electro-hydraulic actuator system leakage fault analysis method

Abstract

The invention discloses a leakage fault analysis method for an underwater electro-hydraulic actuator system. The method comprises the following steps: building an underwater electro-hydraulic actuator system model; setting a dynamic leakage node in the underwater electro-hydraulic actuator system model; a deep sea pressure compensator module is loaded in the underwater electro-hydraulic actuator system model; simulating leakage through an underwater electro-hydraulic actuator system model to obtain gradient change data of the leakage; establishing a mapping relation between the fault parameters and the underwater electro-hydraulic actuator system performance according to the nonlinear friction, the gap, the saturation effect and the gradient change data; a multi-dimensional fault feature library is constructed according to the effective stroke decline rate of the hydraulic cylinder, the plunger pump outlet pressure fluctuation threshold value and the valve flow coefficient attenuation rate; and finishing discriminant analysis of fault types and severity by combining the mapping relation and the multi-dimensional fault feature library. The deep sea pressure compensator module is embedded in the underwater electro-hydraulic actuator system model, the dynamic compression effect of the sealing element is simulated in real time, and the environmental adaptability of the model is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fault analysis, and in particular to a method for analyzing leakage faults of an underwater electro-hydraulic actuator system. Background Art

[0002] Underwater electro-hydraulic actuator systems, or EHAs, are a key technology that converts electrical energy into hydraulic energy, which is then converted to mechanical energy via hydraulic cylinders or motors, enabling precise control and operation of deep-sea equipment. Traditional hydraulic or mechanical actuators often struggle to meet the high-performance and high-reliability requirements of deep-sea pressures and complex environments, while EHAs offer broad application prospects. However, under deep-sea pressures (60 MPa to 90 MPa), low temperatures, and complex fluid environments, EHA systems are susceptible to leakage failures in hydraulic cylinders, plunger pumps, and valves due to seal failure, leading to system performance degradation or even failure. Currently, fault analysis of underwater EHA systems primarily relies on traditional experimental methods or expert judgment. These methods often rely on single-parameter analysis or empirical judgment, lack systematic research on the effects of multiple fault coupling, and fail to fully consider the dynamic impact of deep-sea pressure on seal performance. This results in low diagnostic accuracy and poor adaptability. Summary of the Invention

[0003] An embodiment of the present invention provides a method for analyzing leakage faults in an underwater electro-hydraulic actuator system, which is used to solve the problems in the prior art where fault analysis of underwater EHA systems mainly relies on traditional experimental methods or expert judgment. Fault analysis methods mostly rely on single parameter analysis or empirical judgment, lack systematic research on the coupling effects of multiple faults, and do not fully consider the dynamic impact of deep-sea high pressure on sealing performance, resulting in low diagnostic accuracy and poor adaptability.

[0004] In one aspect, an embodiment of the present invention provides a method for analyzing leakage failures in an underwater electro-hydraulic actuator system, comprising:

[0005] Build a model of an underwater electro-hydraulic actuator system;

[0006] Loading a deep-sea pressure compensator module into the underwater electro-hydraulic actuator system model;

[0007] Setting a dynamic leakage node in the underwater electro-hydraulic actuator system model;

[0008] Simulating leakage through the underwater electro-hydraulic actuator system model to obtain gradient change data of the leakage;

[0009] Establishing a mapping relationship between fault parameters and underwater electro-hydraulic actuator system performance based on nonlinear friction, clearance and saturation effects and the gradient change data;

[0010] A multi-dimensional fault feature library is constructed based on the hydraulic cylinder effective stroke drop rate, plunger pump outlet pressure fluctuation threshold and valve flow coefficient attenuation rate;

[0011] The mapping relationship and the multi-dimensional fault feature library are combined to complete the discriminant analysis of the fault type and severity.

[0012] In a possible implementation, after completing the discriminant analysis of the fault type and severity by combining the mapping relationship and the multi-dimensional fault feature library, the method further includes:

[0013] Optimizing the model parameters of the underwater electro-hydraulic actuator system by dynamically comparing the results of the discriminant analysis with experimental data;

[0014] A fault repair strategy library is generated to iteratively upgrade the underwater electro-hydraulic actuator system.

[0015] In a possible implementation, the underwater electro-hydraulic actuator system model includes: a hydraulic cylinder, a plunger pump, a servo motor, a flow matching valve, and a deep-sea pressure compensator module.

[0016] In a possible implementation, setting a dynamic leakage node in the underwater electro-hydraulic actuator system model includes:

[0017] Dynamic leakage nodes are set on the piston sealing surface of the hydraulic cylinder, the distribution plate of the plunger pump and the valve core;

[0018] The leakage amount of the dynamic leakage node is adjusted by a flow control valve.

[0019] In a possible implementation, after adjusting the leakage amount of the dynamic leakage node by using a flow control valve, the method further includes:

[0020] The nonlinear effect of high pressure on the deformation of the seal is compensated by the deep-sea pressure compensator module.

[0021] In one possible implementation, the leakage analysis of the hydraulic cylinder includes:

[0022] The leakage amount, piston stroke, speed and reset time of the hydraulic cylinder are monitored and collected to obtain hydraulic cylinder data;

[0023] Leakage analysis of the hydraulic cylinder is performed according to the threshold data of the hydraulic cylinder data.

[0024] In one possible implementation, the leakage analysis of the plunger pump includes:

[0025] The leakage, outlet pressure and shaft torque of the plunger pump are monitored and collected to obtain plunger pump data;

[0026] Leakage analysis of the plunger pump is performed based on threshold data of the plunger pump data.

[0027] In one possible implementation, the leakage analysis of the valve core includes:

[0028] The leakage, inlet pressure, flow coefficient and average flow velocity of the valve core are monitored and collected to obtain valve core data;

[0029] Leakage analysis of the valve core is performed based on threshold data of the valve core data.

[0030] The present invention provides a method for analyzing leakage failures in an underwater electro-hydraulic actuator system, which has the following advantages:

[0031] By embedding a deep-sea pressure compensator module in the underwater electro-hydraulic actuator system model, the dynamic compression effect of deep-sea high pressure on seals can be simulated in real time, thereby improving the environmental adaptability of the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 A flow chart of a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0034] Figure 2 A schematic diagram of the structure of an underwater electro-hydraulic actuator system model for a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0035] Figure 3 A comparison diagram of the piston rod stroke of a hydraulic cylinder at different leakage levels in a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0036] Figure 4 A comparison chart of the maximum strokes of a hydraulic cylinder at different leakage levels in a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0037] Figure 5 A comparison chart of the outlet pressure of a plunger pump at different leakage levels for a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0038] Figure 6A graph showing the maximum outlet pressure variation of a plunger pump at different leakage rates for a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0039] Figure 7 A comparison diagram of the shaft torque of a plunger pump at different leakage levels for a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0040] Figure 8 A graph showing changes in the maximum shaft torque of a plunger pump at different leakage levels for a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0041] Figure 9 A comparison diagram of the inlet pressure of a valve core at different leakage rates for a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0042] Figure 10 A diagram showing the maximum inlet pressure variation of a valve core at different leakage rates in a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0043] Figure 11 A comparison chart of the outlet flow rates of a valve core at different leakage levels in a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0044] Figure 12 A diagram showing the maximum outlet flow rate variation of a valve core at different leakage rates in a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0045] Figure 13 A comparison chart of average flow rates of valve cores at different leakage levels in a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0046] Figure 14 A diagram showing the maximum average flow rate variation of a valve core at different leakage levels in a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0047] Figure 15 A comparison chart of flow coefficients of valve cores at different leakage rates for a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application;

[0048] Figure 16 A diagram showing changes in the maximum flow coefficient of a valve core under different leakage rates in a method for analyzing leakage failure of an underwater electro-hydraulic actuator system provided in an embodiment of the present application.

[0049] Explanation of the numbers in the figure: 1. Hydraulic cylinder; 2. Plunger pump; 3. Deep-sea motor; 4. Overflow valve; 5. Flow matching valve; 6. Pressure transmitter; 7. Load controller; 8. Speed ​​sensor; 9. Displacement sensor. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] Figure 1 A schematic flow chart of a method for analyzing a leakage fault of an underwater electro-hydraulic actuator system provided in an embodiment of the present invention. The method for analyzing a leakage fault of an underwater electro-hydraulic actuator system provided in an embodiment of the present invention includes:

[0052] Build a model of an underwater electro-hydraulic actuator system;

[0053] Loading a deep-sea pressure compensator module into the underwater electro-hydraulic actuator system model;

[0054] Setting a dynamic leakage node in the underwater electro-hydraulic actuator system model;

[0055] Simulating leakage through the underwater electro-hydraulic actuator system model to obtain gradient change data of the leakage;

[0056] Establishing a mapping relationship between fault parameters and underwater electro-hydraulic actuator system performance based on nonlinear friction, clearance and saturation effects and the gradient change data;

[0057] A multi-dimensional fault feature library is constructed based on the hydraulic cylinder effective stroke drop rate, plunger pump outlet pressure fluctuation threshold and valve flow coefficient attenuation rate;

[0058] The mapping relationship and the multi-dimensional fault feature library are combined to complete the discriminant analysis of the fault type and severity.

[0059] After completing the discriminant analysis of the fault type and severity by combining the mapping relationship and the multi-dimensional fault feature library, the method further includes:

[0060] Optimizing the model parameters of the underwater electro-hydraulic actuator system by dynamically comparing the results of the discriminant analysis with experimental data;

[0061] A fault repair strategy library is generated to iteratively upgrade the underwater electro-hydraulic actuator system.

[0062] The underwater electro-hydraulic actuator system model includes: a hydraulic cylinder, a plunger pump, a servo motor, a flow matching valve and a deep-sea pressure compensator module.

[0063] After adjusting the leakage amount of the dynamic leakage node by the flow control valve, the method further includes:

[0064] The nonlinear effect of high pressure on the deformation of the seal is compensated by the deep-sea pressure compensator module.

[0065] The leakage amount, piston stroke, speed and reset time of the hydraulic cylinder are monitored and collected to obtain hydraulic cylinder data;

[0066] Leakage analysis of the hydraulic cylinder is performed according to the threshold data of the hydraulic cylinder data.

[0067] The leakage, outlet pressure and shaft torque of the plunger pump are monitored and collected to obtain plunger pump data;

[0068] Leakage analysis of the plunger pump is performed based on threshold data of the plunger pump data.

[0069] The leakage analysis of the valve core includes:

[0070] The leakage, inlet pressure, flow coefficient and average flow velocity of the valve core are monitored and collected to obtain valve core data;

[0071] Leakage analysis of the valve core is performed based on threshold data of the valve core data.

[0072] For example, after the model is built, the signal size of the flow control valve signal generator is changed in the AMESim model to adjust the opening of the flow control valve and obtain operating conditions with different leakage amounts of the component. By observing the flow rate at both ends of the flow control valve, the flow through the flow control valve under the current signal control, that is, the leakage amount of the component, can be obtained. After the simulation is completed, the corresponding data is sorted to obtain the change pattern of the piston rod stroke of the hydraulic cylinder under different leakage amounts, the change pattern of the outlet pressure and shaft torque of the plunger pump under different leakage amounts, and the change pattern of the inlet pressure, outlet flow rate, average flow rate and flow coefficient of the flow matching valve under different leakage amounts. A mapping relationship between fault parameters and system performance is established, providing a data foundation for the subsequent establishment of the underwater EHA system fault diagnosis model.

[0073] The underwater electro-hydraulic actuator system model that is adaptive to deep sea environment is as follows: Figure 2 As shown, it includes: a hydraulic cylinder 1, a plunger pump 2, a deep-sea motor 3, a relief valve 4, a flow matching valve 5, a pressure transmitter 6, a load controller 7, a speed sensor 8 and a displacement sensor 9.

[0074] The deep-sea motor 3 is mechanically connected to the plunger pump 2, which drives the operation of the deep-sea motor 3. The output of the plunger pump 2 is connected to the hydraulic cylinder 1 via a pipeline, providing it with high-pressure hydraulic oil. A flow matching valve 5 is connected to this oil circuit to adjust the flow rate differences during the reciprocating motion of the hydraulic cylinder 1 to ensure uniform motion. A relief valve 4 connects the system pipeline to the closed oil tank, forming a deep-sea pressure compensator model to maintain stable system pressure. A pressure transmitter 6 is installed in the pipeline to collect pressure signals. The hydraulic cylinder 1 is connected to a speed sensor 8 and a displacement sensor 9, which transmit speed and displacement signals to the data collection equipment respectively. A load controller 7 is connected to the system via a signal line and changes the signal value to adjust the load output of the hydraulic cylinder 1 to simulate different working conditions.

[0075] Dynamic leakage nodes were set at the piston sealing surface of the hydraulic cylinder 1, the valve plate of the plunger pump 2, and the valve core of the relief valve 4. The leakage rate was adjusted by the flow matching valve 5 to simulate a gradient leakage condition of 0 to 63 mL / min. A deep-sea pressure compensator module was also embedded, inputting a dynamic pressure signal of 60 MPa to 90 MPa.

[0076] Hydraulic cylinder 1 leakage analysis: Set the leakage rate to 0mL / min, 6.55mL / min, 25.3mL / min, and 62.7mL / min, and monitor the piston stroke, speed, and reset time. When the leakage rate is ≥6.55mL / min, the effective stroke decrease rate exceeds 3%, triggering a first-level warning; when the leakage rate is ≥25.3mL / min, the piston reset delay exceeds 15%, triggering a second-level fault indicator (data analysis as shown in the figure). Figure 3 、 4 ).

[0077] Plunger pump leakage analysis: Set the leakage rate to 0mL / min, 6.55mL / min, 25.1mL / min, and 58.3mL / min, and monitor the outlet pressure and shaft torque. When the leakage rate is ≥25.1mL / min, the outlet pressure fluctuation exceeds ±15%, and the shaft torque attenuation rate exceeds 20%, it is determined that the pump body seal has failed (such as Figure 5-8 ).

[0078] Valve leakage analysis: Set the leakage rate to 0mL / min, 10.5mL / min, 26.6mL / min, and 63.0mL / min, and monitor the inlet pressure, flow coefficient, and average flow rate. When the leakage rate is ≥26.6mL / min, the flow coefficient attenuation rate exceeds 20%, and the valve adjustment function is determined to be invalid (such as Figure 9-16 ).

[0079] Then, based on the simulation data, a "leakage volume-performance attenuation" relationship curve is constructed, key threshold criteria are extracted, and a fault feature coding library is generated. The model accuracy is verified by comparison with experimental data. When the error rate is ≤5%, a diagnostic report is output and targeted maintenance plans are recommended (such as replacing the seal or adjusting the compensator parameters). The simulation model parameters are iteratively optimized to improve the predictive reliability of the system under extreme working conditions. In order to verify the accuracy and reliability of the simulation model, the simulation results are compared and analyzed with the experimental results. Based on the comparison results, the simulation model is optimized and adjusted to improve the accuracy and reliability of the simulation analysis. At the same time, the simulation model can also be used to predict and evaluate the performance of the underwater EHA system, providing strong support for the design and optimization of the system.

[0080] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications that fall within the scope of the present invention and the preferred embodiments.

[0081] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for analyzing leakage failure of an underwater electro-hydraulic actuator system, characterized in that: include: Build a model of an underwater electro-hydraulic actuator system; Loading a deep-sea pressure compensator module into the underwater electro-hydraulic actuator system model; Setting a dynamic leakage node in the underwater electro-hydraulic actuator system model; Simulating leakage through the underwater electro-hydraulic actuator system model to obtain gradient change data of the leakage; Establishing a mapping relationship between fault parameters and underwater electro-hydraulic actuator system performance based on nonlinear friction, clearance and saturation effects and the gradient change data; A multi-dimensional fault feature library is constructed based on the hydraulic cylinder effective stroke drop rate, plunger pump outlet pressure fluctuation threshold and valve flow coefficient attenuation rate; The mapping relationship and the multi-dimensional fault feature library are combined to complete the discriminant analysis of the fault type and severity.

2. The method for analyzing leakage failure of an underwater electro-hydraulic actuator system according to claim 1, characterized in that: After completing the discriminant analysis of the fault type and severity by combining the mapping relationship and the multi-dimensional fault feature library, the method further includes: Optimizing the model parameters of the underwater electro-hydraulic actuator system by dynamically comparing the results of the discriminant analysis with experimental data; A fault repair strategy library is generated to iteratively upgrade the underwater electro-hydraulic actuator system.

3. The method for analyzing leakage failure of an underwater electro-hydraulic actuator system according to claim 1, characterized in that: The underwater electro-hydraulic actuator system model includes: a hydraulic cylinder, a plunger pump, a servo motor, a flow matching valve and the deep-sea pressure compensator module.

4. The method for analyzing leakage failure of an underwater electro-hydraulic actuator system according to claim 3, characterized in that: The step of setting a dynamic leakage node in the underwater electro-hydraulic actuator system model includes: Dynamic leakage nodes are set on the piston sealing surface of the hydraulic cylinder, the distribution plate of the plunger pump and the valve core; The leakage amount of the dynamic leakage node is adjusted by a flow control valve.

5. The method for analyzing leakage failure of an underwater electro-hydraulic actuator system according to claim 4, characterized in that: After adjusting the leakage amount of the dynamic leakage node by the flow control valve, the method further includes: The nonlinear effect of high pressure on the deformation of the seal is compensated by the deep-sea pressure compensator module.

6. The method for analyzing leakage failure of an underwater electro-hydraulic actuator system according to claim 4, characterized in that: The leakage analysis of the hydraulic cylinder includes: The leakage amount, piston stroke, speed and reset time of the hydraulic cylinder are monitored and collected to obtain hydraulic cylinder data; Leakage analysis of the hydraulic cylinder is performed according to the threshold data of the hydraulic cylinder data.

7. The method for analyzing leakage failure of an underwater electro-hydraulic actuator system according to claim 4, characterized in that: The leakage analysis of the plunger pump includes: The leakage, outlet pressure and shaft torque of the plunger pump are monitored and collected to obtain plunger pump data; Leakage analysis of the plunger pump is performed based on threshold data of the plunger pump data.

8. The method for analyzing leakage failure of an underwater electro-hydraulic actuator system according to claim 4, characterized in that: The leakage analysis of the valve core includes: The leakage, inlet pressure, flow coefficient and average flow velocity of the valve core are monitored and collected to obtain valve core data; Leakage analysis of the valve core is performed based on threshold data of the valve core data.

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