Hybrid propulsion system cross coupling fault diagnosis method and system

Abstract

The invention discloses a hybrid propulsion system cross coupling fault diagnosis method and system, and the method comprises the following steps: 1, building a coupling model between an air condition and a ground condition through analyzing the motion state data of an aerocar in an air-ground conversion process; 2, researching a functional coupling relationship between a turboshaft engine and a motor actuator based on a hovercar motion state coupling result in the step 1; and 3, based on the fault prediction characteristic value in the step 2, continuously monitoring sensor data and an actuator state by the system, and performing real-time fault diagnosis based on cross coupling characteristics to obtain system real-time diagnosis feedback and adjustment suggestions. According to the invention, accurate coupling analysis between air and ground working conditions is realized, and fault diagnosis and early warning can be carried out on coupling characteristics in the air take-off stage and the ground landing stage by monitoring motion state data in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of fault diagnosis of a flying car power system, and in particular to a hybrid propulsion system cross-coupling fault diagnosis method and system. Background Art

[0002] As a representative of future transportation, flying cars combine the characteristics of cars and aircraft, and can effectively alleviate the problem of ground traffic congestion. With the advancement of technology and the development of electrification, hybrid propulsion systems are gradually being applied to the field of flying cars and play a key role. In the hybrid propulsion system of flying cars, there is a significant coupling relationship between the motion states in the air and on the ground, and there is also a complex coupling between the functions of the actuators in the propulsion system (such as turboshaft engines and motors). How to fully consider these cross-coupling relationships and effectively apply them to the prediction of system failures has become a technical problem that the industry urgently needs to solve. At present, the research on fault diagnosis of hybrid propulsion systems of flying cars is not very comprehensive, and some existing related technical solutions can provide some references for research in this field. For example, in the Chinese invention patent application number CN202310030052.2, entitled "A flying car wire-controlled chassis control system", it is mentioned that flying cars should be suitable for both land and air use, so the structures of various chassis systems should have redundant characteristics so that they can play a role in fault diagnosis and special circumstances. The fault diagnosis module of its wire-controlled chassis system takes into account the coupling relationship between the air and the ground, obtains expected data input through signal reception and processing, obtains real-time data input through the detection system, and performs fault diagnosis after preprocessing; the Chinese invention patent application number is CN 202210917909.8, entitled "Flying car self-test method, equipment and computer-readable storage medium", which proposes to divide the flying car system into a flight system and a land system. The two major systems each contain multiple subsystems, and each subsystem parameter is individually diagnosed to form a target control strategy; the Chinese invention patent application number is CN 202410916533.8, entitled "Hybrid vehicle diagnostic method, device and medium", which proposes a fault diagnosis method for vehicle components, engine components and drive motor components by coupling the engine and drive motor and coupling the processors respectively.

[0003] However, although these existing technologies have solved the fault diagnosis problem in hybrid propulsion systems to a certain extent, there are still two major shortcomings: First, in terms of fault prediction, existing technologies mostly focus on fault prediction of a single actuator or under specific working conditions, ignoring the functional coupling between different actuators and the interaction during the air-to-ground conversion process. Due to the failure to fully utilize the coupling characteristics inside and outside the system, these solutions are often unable to accurately predict the occurrence of faults in advance when faced with complex working conditions. Secondly, in the design of fault diagnosis methods, existing technologies usually perform fault diagnosis on a single component or a single working condition, and fail to fully consider the functional cross-coupling between the actuators within the system. This approach ignores the possibility of maintaining the overall function of the system by utilizing the functional coupling of other actuators when some functions of the system fail, resulting in low reliability of the diagnosis results under complex working conditions.

[0004] Therefore, how to further develop a fault diagnosis method that can comprehensively utilize the coupling characteristics between the actuators and between the air-ground working conditions in the hybrid propulsion system has become an important issue to improve the reliability and safety of the hybrid propulsion system. The present invention aims to provide a hybrid propulsion system fault diagnosis method based on cross-coupling characteristics, which improves the accuracy of fault prediction and diagnosis through in-depth analysis of the system coupling characteristics, and ensures the efficient operation and stability of the system under complex working conditions. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the problems existing in the above-mentioned existing hybrid propulsion system cross-coupling fault diagnosis method and system, the present invention is proposed.

[0007] Therefore, the purpose of the present invention is to provide a cross-coupling fault diagnosis method and system for a hybrid propulsion system, which solves the problem in the prior art that when predicting and diagnosing system faults, it is difficult to effectively utilize the coupling characteristics between the actuators and the air-ground working conditions, resulting in inaccurate fault prediction and unreliable diagnosis results of the hybrid propulsion system under complex working conditions, and it is impossible to fully utilize the advantages of the internal functional coupling of the system for efficient fault diagnosis.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a hybrid propulsion system cross-coupling fault diagnosis method, comprising the following steps: Step 1: By analyzing the motion state data of the flying car during the air-to-ground conversion process, a coupling model between the air and ground conditions is established to obtain the coupling characteristic data of the impact of the ground acceleration process on the air takeoff stage or the impact of the air flight attitude on the ground landing stability, so as to perform fault diagnosis and monitor the motion state coupling results of the flying car in real time; Step 2: Based on the flying car motion state coupling results in step 1, the functional coupling relationship between the turboshaft engine and the motor actuator is studied. By analyzing the impact of the motor output power fluctuation on the working state of the turboshaft engine, the specific impact range of the turboshaft engine and motor functional coupling is obtained, and a fault prediction model based on historical data and real-time monitoring data is established to predict the probability and time of potential faults, set fault thresholds, and output fault prediction feature values; Step 3: Based on the fault prediction characteristic values ​​in step 2, the system will continuously monitor sensor data and actuator status, and perform real-time fault diagnosis based on cross-coupling characteristics to obtain real-time diagnostic feedback and adjustment suggestions. When an abnormality is detected, the system will automatically adjust the working mode of the hybrid propulsion system and output the adjusted propulsion system parameters to ensure flight safety and avoid further expansion of the fault.

[0009] As a preferred solution of the hybrid propulsion system cross-coupling fault diagnosis method of the present invention, the step 1 specifically includes: 11) By analyzing the motion state data of the flying car during ground acceleration and the attitude angle of the take-off stage in the air, a coupling model between ground and air conditions is established, the influence coefficients α1 and β1 are obtained, and a preliminary coupling equation is constructed: , where M c represents the combined effect of the coupled model, V g is the ground acceleration, θ a is the aerial attitude angle; 12) Based on the coupling model M obtained in step 11) c , further analyze the influence of the aerial flight attitude on the ground landing stability, obtain the coupling characteristic parameters γ1 and γ2, and update the coupling formula as follows: , where S c Indicates the landing stability after coupling, A a is the air attitude parameter.

[0010] As a preferred solution of the hybrid propulsion system cross-coupling fault diagnosis method of the present invention, the step 2 specifically includes: 21) Based on the coupling model M in step 1 c and S c, the coupling relationship between the turboshaft engine output power and the motor output power is studied, the influence of motor power fluctuation on the turboshaft engine is analyzed, the coupling coefficients λ1 and λ2 are obtained, and the coupling equation is established: , where P t is the output power of the turboshaft engine, P e is the output power of the motor; 22) Based on the coupling equation in step 21), using the historical data H d and real-time monitoring data R m , establish the fault prediction model F p , calculate the probability P of potential failures through machine learning algorithms or physics-based models f and time T f : , where f ( , ) is the probability calculation function and g ( , ) is the time calculation function; 23) According to the fault prediction model F in step 22) p , set the fault threshold δ f , when P f ≥δ f When the system outputs the fault prediction report R f , and recommended preventive measures: .

[0011] As a preferred solution of the hybrid propulsion system cross-coupling fault diagnosis method of the present invention, the step three specifically includes: 31) Based on the fault prediction report R in step 23) f , the system continuously monitors the data S of each sensor d and actuator state A s , using the coupled model M c and the functional coupling equation P t , diagnose the fault source in real time and evaluate the fault impact range, and obtain the fault impact parameter η and the fault source location parameter λ s : , where f ( ) is the fault impact parameter calculation function, g ( ) is the fault source location parameter calculation function; 32) Based on the diagnosis results in step 31), generate a fault diagnosis report R d The system automatically adjusts the working mode of the hybrid propulsion system according to the report. The adjusted propulsion system parameters P adj satisfy: ; 33) According to the adjustment result in step 32), the system updates the control strategy of the propulsion system in real time to ensure that the adjusted parameter P adj Meet flight safety requirements.

[0012] A cross-coupling fault diagnosis system for a hybrid propulsion system, comprising: a turboshaft engine module, a motor module, a power coupler, a power management module, an air-to-ground conversion control module, a sensor unit module, and a fault diagnosis controller based on cross-coupling characteristics; The turboshaft engine module includes: an air intake device, a compressor, a combustion chamber, a power turbine, an exhaust device, a turboshaft reduction mechanism and an output shaft; the air intake device is connected to the compressor to introduce external air and send it into the compressor; the compressor is connected to the combustion chamber; the combustion chamber is connected to the power turbine to generate high-temperature and high-pressure gas by mixing air and fuel and igniting them to drive the power turbine; the power turbine is connected to the exhaust device to discharge the combustion exhaust gas, and is connected to the turboshaft reduction mechanism through the output shaft to convert the gas energy into mechanical energy and transmit it to the turboshaft reduction mechanism; the turboshaft reduction mechanism regulates the speed of the output shaft to adapt to different working conditions and environmental requirements; The motor module includes: a motor, a reducer and a motor control unit; the motor is connected to the reducer; the reducer adjusts the output speed of the motor to adapt to different working conditions and environmental requirements; the motor control unit is connected to the motor and the reducer to monitor and control them in real time; The air intake device, compressor and combustion chamber in the turboshaft engine module adopt a compact integrated design to improve the efficiency and response speed of power output; the reducer and motor control unit in the motor module adopt a modular design to facilitate maintenance and function expansion; the output of the turboshaft engine module and the motor module is connected to the output drive shaft through a power coupler to achieve synchronous power output; The power management module is connected to the turboshaft engine module, the motor module and the power coupler, is responsible for coordinating the power distribution and conversion between the turboshaft engine module and the motor module, and adopts an integrated design; The air-to-ground conversion control module smoothly switches between air and ground operating conditions by monitoring the current environmental state; the output signal of the air-to-ground conversion control module is transmitted to the power management module and the fault diagnosis controller to achieve power coordination and fault monitoring during the operating condition conversion; The sensor unit module is used to continuously monitor the turboshaft engine module, the motor module and the power coupler, and its input includes the combustion chamber temperature, the compressor pressure, the output speed of the turboshaft engine module, the output speed of the motor module and the bus current parameter, and the above data is summarized and processed and output to the fault diagnosis controller; The fault diagnosis controller adopts a design based on cross-coupling characteristics, and monitors the functional coupling state between the turboshaft engine module and the motor module, as well as the conversion between air and ground working conditions in real time through feedback from the sensor unit module and the air-to-ground conversion control module.

[0013] As a preferred solution of the cross-coupling fault diagnosis system of the hybrid propulsion system of the present invention, wherein: under air conditions, the power management module gives priority to the output of the turboshaft engine module, and adjusts the auxiliary output of the motor module as needed; under ground conditions, the power management module gives priority to the power output of the motor module, and provides additional power through the assistance of the turboshaft engine module to meet the needs of ground operation.

[0014] As a preferred solution of the cross-coupling fault diagnosis system of the hybrid propulsion system described in the present invention, when a potential fault is detected, the fault diagnosis controller can make a fault warning according to the coupling characteristics and initiate appropriate emergency measures to ensure the stability and safety of the system.

[0015] As a preferred solution of the cross-coupling fault diagnosis system of the hybrid propulsion system described in the present invention, wherein: during the operation of the system, the power management module adjusts the output ratio of the turboshaft engine module and the motor module through the power coupler to adapt to the power requirements under different working conditions; when the fault diagnosis controller detects a fault, it can adjust the distribution ratio of the power coupler and reconfigure the power output path through the power management module to continue to maintain the normal operation of the system and ensure the system reliability and safety under complex working conditions.

[0016] Beneficial effects of the present invention: 1. The present invention not only considers the motion state coupling of the flying car in the process of air-to-ground conversion, and realizes accurate coupling analysis between air and ground working conditions, but also can perform fault diagnosis and early warning on the coupling characteristics of the air takeoff and ground landing stages by real-time monitoring of motion state data, thus ensuring the stability and safety of the flying car under complex working conditions; 2. The present invention has conducted an in-depth study of the functional coupling relationship between turboshaft engines and actuators such as motors, and established a fault prediction model based on historical data and real-time monitoring data. By introducing the setting of key coupling parameters and fault thresholds, accurate monitoring and early warning of functional coupling between actuators are achieved, and a prediction report can be provided before potential faults occur, thereby improving the system's fault prediction capability and response speed; 3. The present invention also considers real-time diagnosis and system adjustment after a fault occurs. Through the established fault diagnosis model, the system can quickly locate the source of the fault and evaluate its impact range, and automatically adjust the working mode of the hybrid propulsion system to ensure flight safety. In the event of partial actuator failure, the system can still achieve functional control of the propulsion system through adjusted parameters, improving the fault tolerance and system safety of the flying car in a fault state. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 creative labor. Among them: Figure 1 It is a schematic structural diagram of the hybrid propulsion system of the present invention; Figure 2 It is a schematic diagram of the structure of the turboshaft engine module; Figure 3 It is a schematic diagram of the motor module structure; Figure 4 It is a principle flow chart of the method of the present invention; In the figure: 1. turboshaft engine module; 2. motor module; 3. power coupler; 4. power management module; 5. air-ground conversion control module; 6. sensor unit module; 7. fault diagnosis controller; 101. air intake device; 102. compressor; 103. combustion chamber; 104. power turbine; 105. exhaust device; 106. turboshaft reduction mechanism; 107. output shaft; 201. electric motor; 202. reducer; 203. motor control unit. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0019] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0020] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0021] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0022] Reference Figure 1-Figure 4, a hybrid propulsion system cross-coupling fault diagnosis method is provided, comprising the following steps: Step 1: By analyzing the motion state data of the flying car during the air-to-ground conversion process, a coupling model between the air and ground conditions is established to obtain the coupling characteristic data of the impact of the ground acceleration process on the air takeoff stage or the impact of the air flight attitude on the ground landing stability, so as to perform fault diagnosis and monitor the motion state coupling results of the flying car in real time; Step 2: Based on the flying car motion state coupling results in step 1, the functional coupling relationship between the turboshaft engine and the motor actuator is studied. By analyzing the impact of the motor output power fluctuation on the working state of the turboshaft engine, the specific impact range of the turboshaft engine and motor functional coupling is obtained, and a fault prediction model based on historical data and real-time monitoring data is established to predict the probability and time of potential faults, set fault thresholds, and output fault prediction feature values; Step 3: Based on the fault prediction characteristic values ​​in step 2, the system will continuously monitor sensor data and actuator status, and perform real-time fault diagnosis based on cross-coupling characteristics to obtain real-time diagnostic feedback and adjustment suggestions. When an abnormality is detected, the system will automatically adjust the working mode of the hybrid propulsion system and output the adjusted propulsion system parameters to ensure flight safety and avoid further expansion of the fault.

[0023] Among them, step one specifically includes: 11) By analyzing the motion state data of the flying car during ground acceleration and the attitude angle of the take-off stage in the air, a coupling model between ground and air conditions is established, the influence coefficients α1 and β1 are obtained, and a preliminary coupling equation is constructed: , where M c represents the combined effect of the coupled model, V g is the ground acceleration, θ a is the aerial attitude angle; 12) Based on the coupling model M obtained in step 11) c , further analyze the influence of the aerial flight attitude on the ground landing stability, obtain the coupling characteristic parameters γ1 and γ2, and update the coupling formula as follows: , where S c Indicates the landing stability after coupling, A a is the air attitude parameter.

[0024] Furthermore, step 2 specifically includes: 21) Based on the coupling model M in step 1 c and S c , the coupling relationship between the turboshaft engine output power and the motor output power is studied, the influence of motor power fluctuation on the turboshaft engine is analyzed, the coupling coefficients λ1 and λ2 are obtained, and the coupling equation is established: , where P t is the output power of the turboshaft engine, P e is the output power of the motor; 22) Based on the coupling equation in step 21), using the historical data H d and real-time monitoring data R m , establish the fault prediction model F p , calculate the probability P of potential failures through machine learning algorithms or physics-based models f and time T f : , where f ( , ) is the probability calculation function and g ( , ) is the time calculation function; 23) According to the fault prediction model F in step 22) p , set the fault threshold δ f , when P f ≥δ f When the system outputs the fault prediction report R f , and recommended preventive measures: .

[0025] Among them, step three specifically includes: 31) Based on the fault prediction report R in step 23) f , the system continuously monitors the data S of each sensor d and actuator state A s , using the coupled model M c and the functional coupling equation P t , diagnose the fault source in real time and evaluate the fault impact range, and obtain the fault impact parameter η and the fault source location parameter λ s : , where f ( ) is the fault impact parameter calculation function, g ( ) is the fault source location parameter calculation function; 32) Based on the diagnosis results in step 31), generate a fault diagnosis report R d The system automatically adjusts the working mode of the hybrid propulsion system according to the report. The adjusted propulsion system parameters P adj satisfy: ; 33) According to the adjustment result in step 32), the system updates the control strategy of the propulsion system in real time to ensure that the adjusted parameter P adj Meet flight safety requirements.

[0026] Specifically, the cross-coupling fault diagnosis system of the hybrid propulsion system includes: a turboshaft engine module 1, a motor module 2, a power coupler 3, a power management module 4, an air-to-ground conversion control module 5, a sensor unit module 6 and a fault diagnosis controller 7 based on cross-coupling characteristics; The turboshaft engine module 1 includes: an air intake device 101, a compressor 102, a combustion chamber 103, a power turbine 104, an exhaust device 105, a turboshaft reduction mechanism 106 and an output shaft 107; the air intake device 101 is connected to the compressor 102, introducing external air and sending it to the compressor 102; the compressor 102 is connected to the combustion chamber 103; the combustion chamber 103 is connected to the power turbine 104, and by mixing air and fuel and igniting them, high-temperature and high-pressure gas is generated to drive the power turbine 104; the power turbine 104 is connected to the exhaust device 105 to discharge the combustion exhaust gas, and is connected to the turboshaft reduction mechanism 106 through the output shaft 107, converting the gas energy into mechanical energy and transmitting it to the turboshaft reduction mechanism 106; the turboshaft reduction mechanism 106 regulates the speed of the output shaft 107 to adapt to different working conditions and environmental requirements; The motor module 2 includes: a motor 201, a reducer 202 and a motor control unit 203; the motor 201 is connected to the reducer 202; the reducer 202 adjusts the output speed of the motor to adapt to different working conditions and environmental requirements; the motor control unit 203 is connected to the motor 201 and the reducer 202 to monitor and control them in real time; The air intake device 101, the compressor 102 and the combustion chamber 103 in the turboshaft engine module 1 adopt a compact integrated design to improve the efficiency and response speed of the power output; the reducer 202 and the motor control unit 203 in the motor module 2 adopt a modular design to facilitate maintenance and function expansion; the output of the turboshaft engine module 1 and the motor module 2 is connected to the output drive shaft through the power coupler 3 to achieve synchronous power output; The power management module 4 is connected to the turboshaft engine module 1, the motor module 2 and the power coupler 3, and is responsible for coordinating the power distribution and conversion between the turboshaft engine module 1 and the motor module 2, and adopts an integrated design; The air-to-ground conversion control module 5 performs smooth conversion between air and ground working conditions by monitoring the current environmental state; the output signal of the air-to-ground conversion control module 5 is transmitted to the power management module 4 and the fault diagnosis controller 7 to achieve power coordination and fault monitoring during the working condition conversion; The sensor unit module 6 is used to continuously monitor the turboshaft engine module 1, the motor module 2 and the power coupler 3. Its input includes the temperature of the combustion chamber 103, the pressure of the compressor 102, the output speed of the turboshaft engine module 1, the output speed of the motor module 2 and the bus current parameter. The above data are summarized and processed and then output to the fault diagnosis controller 7; The fault diagnosis controller 7 adopts a design based on cross-coupling characteristics. Through the feedback of the sensor unit module 6 and the air-to-ground conversion control module 5, it monitors the functional coupling state between the turboshaft engine module 1 and the motor module 2, as well as the conversion between air and ground working conditions in real time.

[0027] Among them, under air conditions, the power management module 4 gives priority to the output of the turboshaft engine module 1, and adjusts the auxiliary output of the motor module 2 as needed; under ground conditions, the power management module 4 gives priority to the power output of the motor module 2, and provides additional power through the assistance of the turboshaft engine module 1 to meet the needs of ground operation.

[0028] Furthermore, when a potential fault is detected, the fault diagnosis controller 7 can make a fault warning according to the coupling characteristics and initiate appropriate emergency measures to ensure the stability and safety of the system. During the operation of the system, the power management module 4 adjusts the output ratio of the turboshaft engine module 1 and the motor module 2 through the power coupler 2 to adapt to the power requirements under different working conditions; when the fault diagnosis controller 7 detects a fault, it can adjust the distribution ratio of the power coupler 3 and reconfigure the power output path through the power management module 4 to continue to maintain the normal operation of the system and ensure the system reliability and safety under complex working conditions.

[0029] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A hybrid propulsion system cross-coupling fault diagnosis method, characterized in that: The following steps are involved: Step 1: By analyzing the motion state data of the flying car during the air-to-ground conversion process, a coupling model between the air and ground conditions is established to obtain the coupling characteristic data of the impact of the ground acceleration process on the air takeoff stage or the impact of the air flight attitude on the ground landing stability, so as to perform fault diagnosis and monitor the motion state coupling results of the flying car in real time; Step 2: Based on the flying car motion state coupling results in step 1, the functional coupling relationship between the turboshaft engine and the motor actuator is studied. By analyzing the impact of the motor output power fluctuation on the working state of the turboshaft engine, the specific impact range of the turboshaft engine and motor functional coupling is obtained, and a fault prediction model based on historical data and real-time monitoring data is established to predict the probability and time of potential faults, set fault thresholds, and output fault prediction feature values; Step 3: Based on the fault prediction characteristic values ​​in step 2, the system will continuously monitor sensor data and actuator status, and perform real-time fault diagnosis based on cross-coupling characteristics to obtain real-time diagnostic feedback and adjustment suggestions. When an abnormality is detected, the system will automatically adjust the working mode of the hybrid propulsion system and output the adjusted propulsion system parameters to ensure flight safety and avoid further expansion of the fault.

2. The hybrid propulsion system cross-coupling fault diagnosis method according to claim 1, characterized in that: The step 1 specifically includes: 11) By analyzing the motion state data of the flying car during ground acceleration and the attitude angle of the take-off stage in the air, a coupling model between ground and air conditions is established, the influence coefficients α1 and β1 are obtained, and a preliminary coupling equation is constructed: , where M c represents the combined effect of the coupled model, V g is the ground acceleration, θ a is the aerial attitude angle; 12) Based on the coupling model M obtained in step 11) c , further analyze the influence of the aerial flight attitude on the ground landing stability, obtain the coupling characteristic parameters γ1 and γ2, and update the coupling formula as follows: , where S c Indicates the landing stability after coupling, A a is the air attitude parameter.

3. The hybrid propulsion system cross-coupling fault diagnosis method according to claim 2, characterized in that: The step 2 specifically includes: 21) Based on the coupling model M in step 1 c and S c , the coupling relationship between the turboshaft engine output power and the motor output power is studied, the influence of motor power fluctuation on the turboshaft engine is analyzed, the coupling coefficients λ1 and λ2 are obtained, and the coupling equation is established: , where P t is the output power of the turboshaft engine, P e is the output power of the motor; 22) Based on the coupling equation in step 21), using the historical data H d and real-time monitoring data R m , establish the fault prediction model F p , calculate the probability P of potential failures through machine learning algorithms or physics-based models f and time T f : , where f ( , ) is the probability calculation function and g ( , ) is the time calculation function; 23) According to the fault prediction model F in step 22) p , set the fault threshold δ f , when P f ≥δ f When the system outputs the fault prediction report R f , and recommended preventive measures: .

4. The hybrid propulsion system cross-coupling fault diagnosis method according to claim 3, characterized in that: The step three specifically includes: 31) Based on the fault prediction report R in step 23) f , the system continuously monitors the data S of each sensor d and actuator status A s , using the coupled model M c and the functional coupling equation P t , diagnose the fault source in real time and evaluate the fault impact range, and obtain the fault impact parameter η and the fault source location parameter λ s : , where f ( ) is the fault impact parameter calculation function, and g ( ) is the fault source location parameter calculation function; 32) Based on the diagnosis results in step 31), generate a fault diagnosis report R d The system automatically adjusts the working mode of the hybrid propulsion system according to the report. The adjusted propulsion system parameters P adj satisfy: ; 33) According to the adjustment result in step 32), the system updates the control strategy of the propulsion system in real time to ensure that the adjusted parameter P adj Meet flight safety requirements.

5. A hybrid propulsion system cross-coupling fault diagnosis system, characterized in that: include: A turboshaft engine module (1), a motor module (2), a power coupler (3), a power management module (4), an air-to-ground conversion control module (5), a sensor unit module (6), and a fault diagnosis controller (7) based on cross-coupling characteristics; The turboshaft engine module (1) comprises: an air intake device (101), a compressor (102), a combustion chamber (103), a power turbine (104), an exhaust device (105), a turboshaft speed reduction mechanism (106), and an output shaft (107); the air intake device (101) is connected to the compressor (102) to introduce external air and send it into the compressor (102); the compressor (102) is connected to the combustion chamber (103); the combustion chamber (103) is connected to the power turbine (104) to generate high-temperature and high-pressure gas by mixing air and fuel and igniting them, thereby driving the power turbine (104); the power turbine (104) is connected to the exhaust device (105) to discharge combustion exhaust gas, and is connected to the turboshaft speed reduction mechanism (106) through the output shaft (107) to convert gas energy into mechanical energy and transmit it to the turboshaft speed reduction mechanism (106); the turboshaft speed reduction mechanism (106) regulates the rotation speed of the output shaft (107) to adapt to different working conditions and environmental requirements; The motor module (2) comprises: a motor (201), a reducer (202) and a motor control unit (203); the motor (201) is connected to the reducer (202); the reducer (202) adjusts the output speed of the motor to adapt to different working conditions and environmental requirements; the motor control unit (203) is connected to the motor (201) and the reducer (202) to monitor and control them in real time; The air intake device (101) and the compressor (102) and the combustion chamber (103) in the turboshaft engine module (1) adopt a compact integrated design to improve the efficiency and response speed of power output; the reducer (202) and the motor control unit (203) in the motor module (2) adopt a modular design to facilitate maintenance and function expansion; the outputs of the turboshaft engine module (1) and the motor module (2) are connected to the output drive shaft through a power coupler (3) to achieve synchronous power output; The power management module (4) is connected to the turboshaft engine module (1), the motor module (2) and the power coupler (3), is responsible for coordinating the power distribution and conversion between the turboshaft engine module (1) and the motor module (2), and adopts an integrated design; The air-to-ground conversion control module (5) performs a smooth conversion between air and ground operating conditions by monitoring the current environmental state; the output signal of the air-to-ground conversion control module (5) is transmitted to the power management module (4) and the fault diagnosis controller (7) to achieve power coordination and fault monitoring during the operating condition conversion; The sensor unit module (6) is used to continuously monitor the turboshaft engine module (1), the motor module (2) and the power coupler (3), and its input includes the temperature of the combustion chamber (103), the pressure of the compressor (102), the output speed of the turboshaft engine module (1), the output speed of the motor module (2) and bus current parameters, and the above data is aggregated and processed and then output to the fault diagnosis controller (7); The fault diagnosis controller (7) adopts a design based on cross-coupling characteristics, and monitors the functional coupling state between the turboshaft engine module (1) and the motor module (2), as well as the conversion between air and ground working conditions in real time through feedback from the sensor unit module (6) and the air-to-ground conversion control module (5).

6. The hybrid propulsion system cross-coupling fault diagnosis system according to claim 5, characterized in that: In airborne conditions, the power management module (4) gives priority to the output of the turboshaft engine module (1), while adjusting the auxiliary output of the motor module (2) as required; in ground conditions, the power management module (4) gives priority to the power output of the motor module (2), and provides additional power through the assistance of the turboshaft engine module (1) to meet the needs of ground operation.

7. The hybrid propulsion system cross-coupling fault diagnosis system according to claim 5, characterized in that: When a potential fault is detected, the fault diagnosis controller (7) can issue a fault warning based on the coupling characteristics and initiate appropriate emergency measures to ensure the stability and safety of the system.

8. The hybrid propulsion system cross-coupling fault diagnosis system according to claim 5, characterized in that: During the operation of the system, the power management module (4) adjusts the output ratio of the turboshaft engine module (1) and the motor module (2) through the power coupler (2) to adapt to the power requirements under different working conditions; when the fault diagnosis controller (7) detects a fault, it can adjust the distribution ratio of the power coupler (3) and reconfigure the power output path through the power management module (4) to continue to maintain the normal operation of the system and ensure the reliability and safety of the system under complex working conditions.

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