A method, device and system for troubleshooting engineering machinery

Abstract

The present invention provides a method, device and system for troubleshooting engineering machinery. The troubleshooting method first provides a troubleshooting scheme based on fault tree analysis, and provides a troubleshooting process of probability-enhanced fault tree analysis on the basis of the troubleshooting scheme of fault tree analysis. It can effectively solve the problems of strong subjectivity, low efficiency and high cost in the existing troubleshooting process of engineering machinery. At the same time, with the increase of troubleshooting cases, the troubleshooting process can be timely optimized according to the failure rate, fault severity and troubleshooting cost of each component, and the accuracy and efficiency of troubleshooting can be gradually improved. In addition, by integrating mobile terminal applications, operators can obtain diagnostic results and maintenance suggestions at any time, making equipment maintenance more convenient and intelligent.

Description

Technical Field

[0001] The invention relates to a method, a device and a system for troubleshooting engineering machinery, and belongs to the field of engineering machinery. Background Art

[0002] The operating parameters of the electro-hydraulic system of construction machinery are complex and the faults are highly hidden, which makes it difficult to diagnose faults in the electro-hydraulic system. At present, traditional troubleshooting mainly relies on manual observation and experience judgment, which has problems such as strong subjectivity, low efficiency and high cost. With the development of intelligent construction machinery, there is an urgent need for an efficient and accurate troubleshooting method and system to improve equipment maintenance efficiency and reduce fault repair time and cost.

[0003] At present, there are three main methods for implementing engineering machinery fault troubleshooting, namely, fault diagnosis technology based on maintenance manuals, fault diagnosis method based on case reasoning, and fault tree analysis method.

[0004] Fault diagnosis technology based on maintenance manuals. This technology modularizes the data in maintenance manuals and uses intelligent retrieval technology and data link technology to achieve accurate and efficient query of manual data.

[0005] The fault diagnosis method based on case reasoning saves and records the maintenance data of engineering machinery through a reasonable method and stores the maintenance data in the case library in the form of case knowledge, and uses data mining algorithms and case-based reasoning to realize engineering machinery fault diagnosis. This method can make full use of previous successful troubleshooting experience, based on the collected and continuously enriched fault cases, to efficiently complete the fault diagnosis of engineering machinery, effectively shorten the maintenance time of engineering machinery, and reduce maintenance costs.

[0006] Fault tree analysis method, this method gradually refines the causes of system failure from the overall to the local in a tree-like manner, is a behavioral model based on the structure and functional characteristics of the diagnosis object, and is a qualitative causal model. Through this method, we can solve the problem of complex system structure and difficult fault analysis, and provide a way to realize the fault diagnosis system.

[0007] In the industry, Caterpillar (CAT) has developed a fault diagnostic instrument and its matching diagnostic software CAT ET. Through these tools, technicians can read the fault code of the equipment and collect real-time operating data; CAT's SIS service information system further supports the troubleshooting and maintenance process. The CAT SIS system contains comprehensive technical information such as fault modes, troubleshooting solutions, and maintenance steps, and is combined with remote same-screen technology to provide real-time assistance. At present, the Caterpillar SIS system does not provide a troubleshooting solution for difficult electro-hydraulic systems, and the knowledge base only contains maintenance solutions such as disassembly, assembly, and cleaning of hydraulic components.

[0008] The above three methods are analyzed to summarize the shortcomings of the current engineering machinery electro-hydraulic system troubleshooting technology:

[0009] The fault diagnosis method based on maintenance manuals relies on the comprehensiveness and accuracy of the manual data. If the manual information is not updated in a timely manner or is not detailed enough, the diagnosis effect may be affected.

[0010] Fault diagnosis methods based on case reasoning rely on the quality and quantity of the existing case library. When new fault types are not recorded or the case data is not rich enough, the diagnostic accuracy may be low.

[0011] The fault tree analysis method is suitable for fault analysis with known structures and logical relationships, but it is difficult to cover faults with complex or unknown causes. The fault tree analysis method mainly uses qualitative analysis to display the cause-effect relationship of faults through a tree model to identify possible fault paths in the system. However, the significant disadvantage of this method is its limitation of qualitative analysis and its inability to provide quantitative analysis, which is specifically manifested in the following aspects:

[0012] (1) Lack of quantitative failure probability assessment: Fault tree analysis can identify the paths that may lead to system failure, but it cannot accurately calculate the probability of each failure event. For scenarios that require quantitative risk assessment, qualitative results are difficult to meet the needs and cannot provide accurate probability data support for decision-making.

[0013] (2) Difficulty in reliability prediction and life assessment: Since fault tree analysis only focuses on the logical relationship of fault events and has no quantitative data support, it is difficult to predict the overall reliability of the system or the life of key components. This limits the application of this method in reliability analysis and preventive maintenance.

[0014] (3) Unable to quantify the impact of faults: Fault tree analysis can only point out potential causes of faults, but cannot evaluate the impact of different faults on system performance. This makes it difficult to determine the optimal maintenance strategy or priority fault path through quantitative means in practical applications.

[0015] A large number of fault tree technology studies have been carried out in the academic field. However, when using the fault tree analysis method to develop a fault diagnosis plan for the electro-hydraulic system of engineering machinery, there are several major limitations, which make it difficult to develop an efficient plan:

[0016] (1) Limitations of complex system knowledge: The electro-hydraulic system of construction machinery contains knowledge from multiple disciplines such as hydraulics, electrical engineering, and control, and its operating parameters are complex. Although university researchers have a solid theoretical foundation, they lack industry experience in equipment structure, component failure modes, and specific operating characteristics, and are unable to accurately analyze the mechanism of electro-hydraulic system failures.

[0017] (2) Lack of dynamic updating of fault data: The failure rate of the electro-hydraulic system of construction machinery is affected by many factors such as the environment, load, and operating habits. These data require long-term on-site operation records and statistics, but it is difficult for universities to track and collect the failure rate data of actual equipment over a long period of time. Without these accurate failure rate data, the fault tree model can only be based on theoretical or experimental speculation, resulting in a lack of pertinence in its diagnostic solution. Summary of the invention

[0018] The present invention provides a method, device and system for troubleshooting engineering machinery faults, which solve the problems of inaccurate diagnosis and positioning of engineering machinery faults and low troubleshooting efficiency in the background technology.

[0019] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0020] A method for troubleshooting engineering machinery, comprising:

[0021] According to the stored historical fault data, the fault type is used as the top fault event and a fault tree analysis model is generated;

[0022] Calculate the failure rate of each electro-hydraulic component failure event, and introduce the failure rate data into a pre-built probability enhanced fault tree analysis model so that each component failure event in the model has a quantified probability;

[0023] Calculate the relative probability importance of each component failure according to the quantified probability;

[0024] Obtain the difficulty of troubleshooting each component failure;

[0025] Get the cost of parts needed to repair the failure;

[0026] Obtain the spare parts resource configuration of each component;

[0027] The fault troubleshooting priority is calculated by comprehensively considering the relative probability importance, troubleshooting difficulty, the cost of parts required to repair the fault, and the allocation of spare parts resources;

[0028] The fault propagation path is determined in the fault tree analysis model according to the fault troubleshooting priority, and the fault propagation path is troubleshooted step by step until the cause of the fault is found.

[0029] Furthermore, troubleshooting follows the principle of electrical first and hydraulic second.

[0030] Furthermore, troubleshooting of the hydraulic section follows the principle of first troubleshooting the pilot oil circuit and then the main oil circuit.

[0031] Furthermore, the main oil circuit is troubleshooted in the order of power elements, control elements, and actuators.

[0032] Furthermore, the failure rate of each electro-hydraulic component failure event is calculated, and the failure rate data is introduced into a pre-built probability enhanced fault tree analysis model so that each component failure event in the model has a quantified probability. The method is as follows:

[0033] According to the historical fault data, the total number of historical faults F, the frequency of occurrence of the top event F0, and the frequency of occurrence of each system fault F are obtained. i , i is the i-th system, each subsystem fault F i,j , j is the jth subsystem, if there is no subsystem, j is omitted, and the frequency of failure of each component F i,j,k , k is the kth part;

[0034] Calculate the probability of occurrence of each top event P0 and the probability of occurrence of each system failure P i , the probability of subsystem failure P i,j and the probability of component failure P i,j,k ;

[0035] The probability of occurrence of each top event: ; Probability of failure of each system: ; Probability of failure of each subsystem: ; Probability of failure of each component: .

[0036] Furthermore, the relative probability importance of each component failure .

[0037] Furthermore, the method for obtaining the troubleshooting difficulty of each component failure is as follows:

[0038] According to the difficulty of troubleshooting, the difficulty of troubleshooting each component is M k Scoring: The scoring principles are:

[0039] 1 point for faults that can be corrected by visual observation;

[0040] The faults that can be corrected by the fault codes displayed on the instrument are worth 0.9 points;

[0041] The faults that can be detected by measuring instruments are 0.7 to 0.8 points;

[0042] Faults that can be corrected by external disassembly are scored 0.4 to 0.6 points;

[0043] The faults that can be detected by disassembly are 0.1 points to 0.3 points.

[0044] Furthermore, the method for obtaining the cost of parts required to repair the fault is:

[0045] Based on the cost of parts needed to repair the fault Ck Scoring: The scoring principles are:

[0046] Low-value components are 0.9 points to 1 point;

[0047] Medium value components are 0.6 to 0.8 points;

[0048] Higher value components are 0.3 points to 0.5 points;

[0049] High-value components are 0.1 points to 0.2 points.

[0050] Furthermore, the method for obtaining the spare parts resource configuration status of each component is:

[0051] Spare parts resource allocation for each component N k Scoring, scoring principles are:

[0052] 1 point for sufficient spare parts resources;

[0053] If the goods need to be transferred nearby, the score is 0.7 to 0.9 points;

[0054] The need for remote transfer of goods is 0.4 points to 0.6 points.

[0055] Furthermore, the method for calculating the troubleshooting priority is:

[0056] Calculate the troubleshooting priority W k , W k The larger the value, the higher the priority;

[0057] ;

[0058] I k is the relative probability importance, ;

[0059] M k To troubleshoot the difficulty, ;

[0060] C k The cost of parts required to repair the fault, The weight of the cost of parts needed to repair the failure;

[0061] N k The spare parts resource configuration. The weight of spare parts resource configuration.

[0062] Further, .

[0063] A second aspect of the present invention provides a construction machinery fault troubleshooting device, comprising:

[0064] A historical case data management module is used to generate a fault propagation path based on the stored historical fault data and taking the fault type as the top fault event;

[0065] Calculate the failure rate of each electro-hydraulic component failure event, and introduce the failure rate data into a pre-built probability enhanced fault tree analysis model so that each component failure event in the model has a quantified probability;

[0066] A fault-guided query module, used to calculate the relative probability importance of each component fault according to the quantified probability;

[0067] Obtain the difficulty of troubleshooting each component failure;

[0068] Get the cost of parts needed to repair the failure;

[0069] Obtain the spare parts resource configuration of each component;

[0070] The fault troubleshooting priority is calculated by comprehensively considering the relative probability importance, troubleshooting difficulty, the cost of parts required to repair the fault, and the allocation of spare parts resources;

[0071] Troubleshoot along the fault propagation path according to the fault troubleshooting priority until the cause of the fault is found.

[0072] A third aspect of the present invention provides an engineering machinery fault troubleshooting system, including a mobile app and a cloud platform;

[0073] The mobile app is provided with a fault diagnosis page, and the fault diagnosis page is linked to the cloud platform;

[0074] The cloud platform is provided with a proxy server and the troubleshooting device as described above, the troubleshooting page accesses the troubleshooting device through the proxy server, and the troubleshooting device is used to provide backend services for the troubleshooting page.

[0075] The beneficial effects achieved by the present invention are:

[0076] The present invention can effectively solve the problems of strong subjectivity, low efficiency and high cost in the existing engineering machinery fault troubleshooting process. At the same time, as the number of troubleshooting cases increases, the troubleshooting process can be optimized in a timely manner according to the failure rate, severity and troubleshooting cost of each component, and the accuracy and efficiency of troubleshooting can be gradually improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is a schematic diagram of a fault tree analysis model of the present invention taking the electro-hydraulic system with no action of bucket swinging outward as an example;

[0078] Figure 2 It is a schematic diagram of the probability enhanced fault tree analysis model of the present invention;

[0079] Figure 3 This is a schematic diagram of the troubleshooting process of the present invention taking the electro-hydraulic system with no action of the bucket swinging outward as an example;

[0080] Figure 4 Schematic diagram of the troubleshooting system of the present invention. DETAILED DESCRIPTION

[0081] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0082] Embodiment 1: This embodiment provides a method for troubleshooting engineering machinery faults. First, a fault tree analysis-based troubleshooting solution is provided. On the basis of the fault tree analysis troubleshooting solution, a probability-enhanced fault tree analysis troubleshooting process is provided to further optimize the troubleshooting process.

[0083] like Figure 1 As shown in the figure, taking the bucket swing-out non-action electro-hydraulic system as an example, a set of standard logical judgment rules based on fault tree analysis is established. The specific steps for rule formulation are as follows:

[0084] Fault Tree Analysis Model Construction:

[0085] Taking the fault type as the top fault event, such as no action, slow action, jitter, etc., based on the failure mode of components, by studying the working principles of the whole machine, electro-hydraulic system and components, analyzing the possible fault causes and manifestations of each subsystem, and determining the fault propagation path. Figure 1 shown.

[0086] Logical judgment rule formulation for troubleshooting:

[0087] Troubleshooting follows the principle of "electrical first, hydraulic second". The hydraulic part further follows the order of "pilot oil circuit first, main oil circuit second". The main oil circuit part is checked in sequence of "power element → control element → actuator". For example, when troubleshooting "bucket swing does not work", first check whether the solenoid valve coil is damaged, and then check the proportional valve, port relief valve, main control valve core, etc. on a sequential basis. Based on the analysis of the cause of the fault, formulate fault logic judgment rules, which include fault top events, cause analysis, troubleshooting steps, and maintenance methods.

[0088] like Figure 2 As shown, based on the above fault tree analysis model, a probability enhanced fault tree analysis method is provided:

[0089] Based on the frequency, occurrence conditions, maintenance history and other data of component failure events, the failure rate of each electro-hydraulic component failure event is calculated, and the failure rate data is introduced into the model so that each component failure event in the model has a clear quantitative probability. The specific steps are as follows:

[0090] According to the historical fault data, the total number of historical faults F, the frequency of occurrence of the top event F0, and the frequency of occurrence of each system fault F are obtained. i (i is the i-th system), each subsystem failure F i,j (j is the jth subsystem. If there is no subsystem, j is omitted) and the frequency of failure of each component F i,j,k (k is the kth part);

[0091] The frequency of occurrence is obtained by statistics, and the probability of occurrence of each top event P0 and the probability of occurrence of each system failure P i , the probability of subsystem failure P i,j and the probability of component failure P i,j,k ;

[0092] The probability of occurrence of each top event: ;

[0093] Probability of failure of each system: ;

[0094] Probability of failure of each subsystem: ;

[0095] The probability of failure of each component: ;

[0096] The calculated probability of occurrence is used to calculate the relative probability importance of each component failure I k ;

[0097] The relative probability importance of each component failure: ;

[0098] The above-mentioned probabilities and relative probability importances are introduced into the fault tree to form a probability enhanced fault tree analysis model.

[0099] Critical Failure Path Identification:

[0100] The fault tree model is used to calculate the probability of occurrence of electro-hydraulic system fault events, quantify the impact of various fault events on system performance, identify the fault chain with the greatest impact on system failure rate, and optimize the fault troubleshooting process based on the troubleshooting cost (mainly considering time and resources). The specific steps are as follows:

[0101] According to the difficulty of troubleshooting, the difficulty of troubleshooting each component is M k Scoring: The scoring principles are:

[0102] 1 point is given to faults that can be detected by visual observation, such as low liquid level, leakage, looseness, breakage, etc.

[0103] The faults that can be corrected by the fault codes displayed on the instrument are worth 0.9 points;

[0104] Faults that can be checked by multimeter, pressure gauge or other instruments or by simple troubleshooting (such as using a screwdriver to approach the solenoid valve to determine whether it is powered), and that do not require disassembly or assembly, are scored 0.7 to 0.8 points;

[0105] Faults that can be checked by external disassembly (such as end covers, proportional valves, etc.) are scored 0.4 to 0.6 points;

[0106] Faults detected through disassembly (such as plunger pumps, motor assemblies, etc.) are scored 0.1 to 0.3 points.

[0107] Based on the cost of repair or maintenance of the parts, the method of cost of parts required is:

[0108] Based on the cost of parts needed to repair the fault C k Scoring: The scoring principles are:

[0109] Low-value components such as seals, one-way valves, and joints are 0.9 to 1 point;

[0110] Medium-value components such as cartridge valves, proportional pressure reducing valves, and pressure sensors are 0.6 to 0.8 points;

[0111] For example, high-value components such as multi-way valves, hydraulic cylinders, and proportional control valves are 0.3 to 0.5 points;

[0112] High-value components such as plunger pumps, motors, and high-performance servo components are 0.1 to 0.2 points.

[0113] According to the resource allocation of parts, the spare parts resource allocation of each component is N k Scoring, scoring principles are:

[0114] 1 point for sufficient spare parts resources;

[0115] Need to transfer goods nearby (can be delivered within 3 days) 0.7 points to 0.9 points;

[0116] The need for remote transfer of goods (cycle > 3 days) is 0.4 to 0.6 points.

[0117] The method for calculating troubleshooting priority is:

[0118] Calculate the troubleshooting priority W k , W k The larger the value, the higher the priority;

[0119] ;

[0120] I k is the relative probability importance, ;M k To troubleshoot the difficulty, ; C k The cost of parts required to repair the fault, The weight of the cost of parts required to repair the failure; N k The spare parts resource configuration. The weight of spare parts resource configuration; .

[0121] Example 2: Apply the troubleshooting method described in Example 1 to troubleshoot the electro-hydraulic system failure of the bucket swinging outward without action as an example; Figure 3 As shown, first check whether the fault code related to the handle communication is displayed. If the fault code related to the handle communication is displayed, it is determined that the handle communication is faulty; otherwise, continue to check whether the fault code related to the bucket outward swing solenoid valve is displayed. If the fault code related to the bucket outward swing solenoid valve is displayed, it is determined that the electrical connection of the bucket outward swing solenoid valve is faulty; otherwise, use a small screwdriver to close the solenoid valve. If there is no suction, it is determined that the coil of the bucket outward swing solenoid valve is damaged; otherwise, swap it with the bucket inward retraction solenoid valve to observe whether the fault is transferred. If the fault is transferred, it is determined that the bucket outward swing proportional valve is stuck; otherwise, swap the port relief valve (B port) with the port relief valve (A port) to observe whether the fault is relieved. If the fault is relieved, it is determined that the port relief valve (B port) is faulty; otherwise, remove the main control valve core to observe whether there is sticking or scratching. If there is sticking or scratching, it is determined that the main control valve core is stuck or scratched.

[0122] Embodiment 3: This embodiment provides a construction machinery fault troubleshooting device, including a historical case data management module and a fault guided query module;

[0123] The historical case data management module is used to collect historical fault data of the electro-hydraulic system of engineering machinery, including information such as the type, cause, diagnostic steps, maintenance plan and processing results of the fault. These data are standardized and stored in categories to form a structured case library. Each case contained in the case library is represented by a fault feature vector so that the system can quickly retrieve and match;

[0124] Retrieval and matching of historical cases: When a device fails, maintenance personnel input the parameter information of the current fault (such as fault phenomenon, operating status, alarm information, etc.) to generate the corresponding fault feature vector. The system uses a similarity calculation algorithm to match the current fault feature vector with the historical fault cases in the case library to find the historical case that is most similar to the current fault feature.

[0125] Fault diagnosis and recommended solutions: Based on the most matching historical cases, the system provides corresponding fault diagnosis suggestions, including possible fault causes and recommended maintenance solutions;

[0126] Case library update: After the troubleshooting is completed, the diagnostic process and results of the fault are recorded and archived, and included in the case library and stored as a new case.

[0127] Fault tree construction, for the hydraulic system, electrical system and engine system of construction machinery, establish a set of standard logical judgment rules based on fault tree analysis. Take the fault type as the top fault event, such as no action, slow action, jitter, etc. By studying the working principle of the electro-hydraulic system and each component, analyzing the relationship between subsystems and components, and based on the failure mode of components, analyzing the possible faults and their manifestations of each subsystem. Determine the propagation path of the fault between different components and establish a standardized fault judgment process;

[0128] The troubleshooting process is formulated. The troubleshooting follows the principle of "electrical first, then hydraulic". The hydraulic part further follows the order of "pilot oil circuit first, then main oil circuit". The main oil circuit part is checked in sequence of "power element → control element → actuator". For example, when troubleshooting "bucket swing does not work", first check whether the solenoid valve coil is damaged, and then check the proportional valve, port relief valve, main control valve core, etc.;

[0129] The fault tree analysis model is constructed based on the frequency, occurrence conditions, maintenance history and other data of component failure events. The failure rate of each electro-hydraulic component failure event is calculated, and the failure rate data is introduced into the model so that each component failure event in the model has a clear quantitative probability.

[0130] The fault-guided query module is used to identify key fault paths. It calculates the probability of occurrence of electro-hydraulic system fault events through the fault tree model, quantifies the impact of various fault events on system performance, identifies the fault chain with the greatest impact on the system failure rate, and optimizes the fault troubleshooting process based on the troubleshooting cost (mainly considering time and resources).

[0131] Example 4: This example uses the above example 3 to develop a historical case data management module and a fault-guided query module. This example provides a solution for integrating the two modules into a mobile terminal. Taking excavator fault diagnosis as an example, Figure 4As shown, a hyperlink is established in the mobile APP. By clicking the link, one can quickly jump from the existing mobile terminal application to the login page of the excavator fault diagnosis expert system and access the cloud platform. The cloud platform is equipped with a proxy server, and the historical case data management module and the excavator fault guided query module provide background services. In order to prevent the historical case data management module and the excavator fault guided query module from being attacked, the cloud platform is also equipped with an interceptor.

[0132] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

[0133] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0134] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0135] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0136] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A method for troubleshooting engineering machinery, characterized in that: include: According to the stored historical fault data, the fault type is used as the top fault event and a fault tree analysis model is generated; Calculate the failure rate of each electro-hydraulic component failure event, and introduce the failure rate data into a pre-built probability enhanced fault tree analysis model so that each component failure event in the model has a quantified probability; Calculate the relative probability importance of each component failure according to the quantified probability; Obtain the difficulty of troubleshooting each component failure; Get the cost of parts needed to repair the failure; Obtain the spare parts resource configuration of each component; The fault troubleshooting priority is calculated by comprehensively considering the relative probability importance, troubleshooting difficulty, the cost of parts required to repair the fault, and the allocation of spare parts resources; The fault propagation path is determined in the fault tree analysis model according to the fault troubleshooting priority, and the fault propagation path is troubleshooted step by step until the cause of the fault is found.

2. The method for troubleshooting engineering machinery according to claim 1, characterized in that: Troubleshooting follows the principle of electrical first and hydraulic second.

3. The engineering machinery fault troubleshooting method according to claim 2 is characterized in that: Troubleshooting for the hydraulic section should follow the principle of first troubleshooting the pilot oil circuit and then the main oil circuit.

4. The engineering machinery fault troubleshooting method according to claim 3 is characterized in that: Troubleshooting for the main oil circuit should be carried out in the order of power components, control components and actuators.

5. The engineering machinery fault troubleshooting method according to claim 1, characterized in that: The method of calculating the failure rate of each electro-hydraulic component failure event and introducing the failure rate data into the pre-built probability enhanced fault tree analysis model so that each component failure event in the model has a quantified probability is as follows: According to the historical fault data, the total number of historical faults F, the frequency of occurrence of the top event F0, and the frequency of occurrence of each system fault F are obtained. i , i is the i-th system, each subsystem fault F i,j , j is the jth subsystem, if there is no subsystem, j is omitted, and the frequency of failure of each component F i,j,k , k is the kth part; Calculate the probability of occurrence of each top event P0 and the probability of occurrence of each system failure P i , the probability of subsystem failure P i,j and the probability of component failure P i,j,k ; The probability of occurrence of each top event: ; Probability of failure of each system: ; Probability of failure of each subsystem: ; Probability of failure of each component: .

6. The engineering machinery fault troubleshooting method according to claim 5, characterized in that: The relative probability importance of each component failure .

7. The engineering machinery fault troubleshooting method according to claim 1, characterized in that: The method for obtaining the troubleshooting difficulty of each component failure is: According to the difficulty of troubleshooting, the difficulty of troubleshooting each component is M k Scoring: The scoring principles are: 1 point for faults that can be corrected by visual observation; The faults that can be corrected by the fault codes displayed on the instrument are worth 0.9 points; The faults that can be detected by measuring instruments are 0.7 to 0.8 points; Faults that can be corrected by external disassembly are scored 0.4 to 0.6 points; The faults that can be detected by disassembly are 0.1 points to 0.3 points.

8. The engineering machinery fault troubleshooting method according to claim 1, characterized in that: The method to obtain the cost of parts required to repair the failure is: Based on the cost of parts needed to repair the fault C k Scoring: The scoring principles are: Low-value components are 0.9 points to 1 point; Medium value components are 0.6 to 0.8 points; Higher value components are 0.3 points to 0.5 points; High-value components are 0.1 points to 0.2 points.

9. The engineering machinery fault troubleshooting method according to claim 1, characterized in that: The method for obtaining the spare parts resource configuration of each component is: Spare parts resource allocation for each component N k Scoring, scoring principles are: 1 point for sufficient spare parts resources; If the goods need to be transferred nearby, the score is 0.7 to 0.9 points; The need for remote transfer of goods is 0.4 points to 0.6 points.

10. The engineering machinery fault troubleshooting method according to claim 1, characterized in that: The method for calculating troubleshooting priority is: Calculate the troubleshooting priority W k , W k The larger the value, the higher the priority; ； I k is the relative probability importance, ; M k To troubleshoot the difficulty, ; C k The cost of parts required to repair the fault, The weight of the cost of parts needed to repair the failure; N k The spare parts resource configuration. The weight of spare parts resource configuration.

11. The engineering machinery fault troubleshooting method according to claim 1, characterized in that: 。 12. A device for troubleshooting engineering machinery, characterized in that: include: A historical case data management module is used to generate a fault propagation path based on the stored historical fault data and taking the fault type as the top fault event; Calculate the failure rate of each electro-hydraulic component failure event, and introduce the failure rate data into a pre-built probability enhanced fault tree analysis model so that each component failure event in the model has a quantified probability; A fault-guided query module, used to calculate the relative probability importance of each component fault according to the quantified probability; Obtain the difficulty of troubleshooting each component failure; Get the cost of parts needed to repair the failure; Obtain the spare parts resource configuration of each component; The fault troubleshooting priority is calculated by comprehensively considering the relative probability importance, troubleshooting difficulty, the cost of parts required to repair the fault, and the allocation of spare parts resources; Troubleshoot along the fault propagation path according to the fault troubleshooting priority until the cause of the fault is found.

13. A construction machinery fault troubleshooting system, characterized in that: Including mobile app and cloud platform; The mobile app is provided with a fault diagnosis page, and the fault diagnosis page is linked to the cloud platform; The cloud platform is provided with a proxy server and the troubleshooting device as claimed in claim 12, the fault diagnosis page accesses the troubleshooting device through the proxy server, and the troubleshooting device is used to provide backend services for the fault diagnosis page.

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