Helicopter hydraulic system joint simulation method based on multiple disciplines

Abstract

The invention belongs to the technical field of hydraulic systems, and discloses a helicopter hydraulic system joint simulation method based on multidisciplinary, which comprises the following steps of: 1, acquiring a hydraulic system demand; 2, performing hydraulic system demand analysis to obtain a hydraulic system case diagram; 3, performing function analysis to obtain an activity diagram, a sequence diagram and a black box state diagram; 4, based on function analysis, system design integration is carried out, a white box state diagram is obtained, and a hydraulic system function logic model based on Rhapsody is built; 5, building a hydraulic system physical performance model based on AMESim on the basis of a Rhapsody hydraulic system physical function model; based on the sequence diagram, simulating a cabin display panel of the hydraulic system in AMESim; 6, building a three-dimensional dynamic visual model of the main rotor and the tail rotor based on CAT IA; 7, the hydraulic system function logic model, the complete hydraulic system physical prototype model and the main tail rotor dynamics three-dimensional visual model are combined; and 8, setting simulation conditions, and carrying out joint simulation.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic systems, and in particular relates to a multi-disciplinary-based joint simulation method for helicopter hydraulic systems. Background Art

[0002] At present, the design of helicopter hydraulic system adopts the model-based system engineering forward design method, but there are still some shortcomings in practical application:

[0003] 1. The transfer between the functional logical architecture obtained from top-down demand development and demand definition and the physical architecture after design synthesis can only be manually converted. There is a lack of corresponding automation tools. The physical function model and the physical performance model built are not related and cannot be verified accordingly.

[0004] 2. Currently, the hydraulic system simulation is in a single form and can only realize the performance simulation verification of important parameters in the system physical architecture design. It cannot jointly verify whether the logic of the system is correct, and cannot intuitively display the impact of hydraulic system changes on each user. Summary of the invention

[0005] Purpose of the invention: To provide a multidisciplinary joint simulation method for helicopter hydraulic systems. By applying simulation technology between physical function models, physical performance models and three-dimensional visual models, it can realize the work of demand confirmation, simulation analysis verification and design iteration in the forward design of hydraulic systems. On the other hand, it can intuitively display the state changes of the hydraulic system during operation and the execution status of system users. It can realize system logic and performance verification in the early stage of hydraulic system design to avoid the high cost caused by later changes.

[0006] Technical Solution

[0007] A multidisciplinary joint simulation method for helicopter hydraulic system, the steps are as follows:

[0008] Step 1: Obtain hydraulic system requirements;

[0009] Step 2: Analyze the requirements of the hydraulic system and obtain a hydraulic system use case diagram to represent the external interface relationship;

[0010] Step 3: Perform functional analysis on each of the above use cases to obtain activity diagrams, sequence diagrams, and black box state diagrams to represent the internal relationships of the system and refine the docking interface relationships;

[0011] Step 4: Based on the activity diagram, sequence diagram, and black box state diagram, perform system design synthesis to obtain a white box state diagram, which is used to represent the specific physical implementation form of the system and build a physical function model of the hydraulic system based on Rhapsody;

[0012] Step 5: Based on the physical function model of the hydraulic system in Rhapsody, build the physical performance model of the hydraulic system based on AMESim; based on the sequence diagram, simulate the cockpit display panel of the hydraulic system in AMESim;

[0013] Step 6: Build a CATIA-based three-dimensional visual model of the main tail rotor dynamics to represent the assembly position and motion relationship of the main tail rotor, as well as the relationship between the hydraulic system and the main tail rotor;

[0014] Step 7: Combine the hydraulic system physical function model, the hydraulic system physical performance model and the main tail rotor dynamics three-dimensional visual model;

[0015] Step 8: Set simulation conditions and perform joint simulation.

[0016] Furthermore, in step 1, the process of obtaining the hydraulic system requirements is as follows:

[0017] According to the definition of the helicopter's full life cycle stages, identify the participants in each stage, including the military, pilots, ground crew, aircrew support personnel, design team, process manufacturing team, test team, and finished product suppliers, and obtain the needs of participants at different stages;

[0018] Extract relevant clauses applicable to hydraulic systems from top-level project documents and standards to form requirement items;

[0019] Obtain similar product design experience / failure information, analyze previous failures, extract requirements that are easy to optimize product functions and improve performance, and form requirement items;

[0020] The requirements obtained from the above three methods are integrated, including selection, merging and sorting, to finally obtain the hydraulic system requirements.

[0021] Further, in step 2, the process is as follows:

[0022] According to the requirements of the hydraulic system, use cases are created in Rhapsody to determine the functions of the hydraulic system, provide hydraulic energy, manage electromechanical information flow and ground maintenance of the system, describe the relationship between all participants and the three functions, and obtain a use case diagram to express the boundaries of the hydraulic system, as well as its interaction with the outside world and its interfaces.

[0023] Further, in step three, the process of obtaining the activity diagram based on the use case diagram is as follows:

[0024] Based on the use case diagram, the three functions of the hydraulic system are divided into multiple activities and operations. The activity diagram is used to represent the logical relationship and workflow between the activities, which is used to represent the internal relationship of the system. The functional logic of "providing pressure energy" is described as follows: when the hydraulic system is powered on, the system is in the power-on state; the main reducer is started, and the mechanical energy is converted into the pressure energy of the hydraulic system; the high-pressure oil is filtered by the storage device and then provided to each user; the return oil connected to the user is returned to the hydraulic storage device through the return oil filter after actuation; when the system pressure is lower than the specified pressure value, the backup hydraulic source is switched to supply pressure; when the system pressure is higher than the specified value, the pressure is relieved through the pressure relief device;

[0025] The functional logic of "managing electromechanical information flow" is described as follows: when the hydraulic system is working, the pressure in the system is monitored and the pressure data is transmitted to the flight control system in real time. When the pressure is lower than the specified value, a low pressure alarm is provided to the pilot; the liquid level in the system is monitored and the liquid level data is transmitted to the flight control system in real time. When the system liquid level is lower than the specified value, a low liquid level alarm is provided to the pilot, and unimportant users with high oil leakage rates are cut off; the oil temperature in the system is monitored and the oil temperature data is transmitted to the flight control system in real time. When the system oil temperature is higher than the specified value, a high oil temperature alarm is provided to the pilot; the oil contamination degree in the system is monitored and the pressure difference data is transmitted to the flight control system in real time. When the pressure difference data is higher than the specified value, an oil contamination alarm is provided to the pilot and ground crew;

[0026] The functional logic of "system ground maintenance" is described as follows: on the ground, ground staff replenish pressure to the hydraulic system manually or automatically; on the ground, ground staff perform power-assisted checks on user actions through the ground hydraulic oil source; on the ground, ground staff replenish oil to the onboard storage device through the ground hydraulic oil source or manually; on the ground, ground staff inspect and repair the hydraulic system.

[0027] Furthermore, in step 3, the process of obtaining the sequence diagram based on the activity diagram is as follows:

[0028] Based on the activity diagram, under the natural environment, mechanical environment, electromagnetic environment, and system safety, maintainability, reliability, testability, supportability, and weight constraints described in the top-level project file in the hydraulic system requirements, the interaction between the hydraulic system and the outside world in each working scenario of the entire flight mission profile of the helicopter and the dynamic sequence between each activity in the activity diagram are analyzed to obtain a sequence diagram to represent the behavior sequence of the use case;

[0029] In the climbing / cruising / combat phases, under the constraints of natural environment, mechanical environment, electromagnetic environment, system safety and reliability, a sequence diagram of user pressure supply scenarios and fault scenarios is drawn. When the power supply system powers on the hydraulic system, the main reducer provides mechanical energy to the hydraulic system. The pilot controls the helicopter through the flight control stick. The hydraulic system provides high-pressure oil at a certain pressure to provide control assistance. The hydraulic system feeds back pressure data, liquid level data, temperature data, and pressure difference data to the flight control system and display system. When the liquid level is lower than the specified value, the system feeds back the fault status to the flight control system and display system. The pilot receives an alarm in the display system, and the control unit in the system automatically cuts off unimportant users with a large leakage rate and prompts the pilot.

[0030] In the hangar stage, under the constraints of the system's storage environment, reliability, maintainability and security, draw a sequence diagram of the ground pressure replenishment, power assist inspection, oil replenishment and maintenance scenarios in the "system ground maintenance" function;

[0031] During the traction taxiing phase, under the electromagnetic environment and reliability indicators, draw sequence diagrams for wheel braking, tail wheel unlocking and pressure supply scenarios, and fault scenarios;

[0032] During the takeoff / landing phase, under the constraints of the natural environment, mechanical environment, electromagnetic environment, system safety, and reliability, draw a sequence diagram of the flight control system pressure supply scenario and fault scenario.

[0033] Furthermore, in step three, the process of obtaining the black box state diagram based on the activity diagram and sequence diagram is as follows:

[0034] Based on the activity diagram and sequence diagram, according to the three functions of the hydraulic system, the working states of each activity in different scenarios in the sequence diagram are comprehensively represented to obtain the black box state diagram, which combines the information of the activity diagram and sequence diagram to represent the working state of the system, the transition between states and the execution operation;

[0035] The working states in the black box state diagram of "providing pressure energy" include normal pressure supply state, auxiliary pressure supply state, overpressure state, flight control pressure supply state, wheel brake pressure supply state, tail wheel unlocking pressure supply state and landing gear pressure supply state;

[0036] The working states in the black box state diagram of "Managing Electromechanical Information Flow" include pressure monitoring state, liquid level monitoring state, temperature monitoring state, pollution monitoring state and alarm state, among which the alarm state includes low pressure alarm state, low liquid level alarm state, over temperature alarm state and pollution alarm state;

[0037] The working states in the black box status diagram of "System Ground Maintenance" include pressurization state, ground refueling state, ground flight assist inspection state, and ground equipment maintenance state.

[0038] Furthermore, in step 4, the system functions in the black box state diagram are allocated to each subsystem, the best physical implementation form of each subsystem function is selected, and system design synthesis is performed to merge the functional similar items in each subsystem, and the system safety, maintainability, reliability, testability, security and weight constraints are comprehensively considered to obtain the white box state diagram;

[0039] The status of each subsystem is run to verify the previous requirements, and a physical function model of the hydraulic system based on Rhapsody is built, which consists of a main hydraulic power unit, a backup hydraulic power unit, and a redundancy conversion device;

[0040] The main hydraulic power unit includes a hydraulic oil tank capable of storing oil, a hydraulic pump capable of converting mechanical energy into hydraulic energy, a level sensor capable of monitoring the liquid level and providing a low oil level alarm, a safety valve capable of overpressure relief, a contamination indicator capable of monitoring oil contamination, an oil filter capable of filtering the oil, a hydraulic self-sealing valve capable of maintenance, and an oil observation window;

[0041] The backup hydraulic power unit includes a hydraulic oil tank that can store oil, a hydraulic pump that can be driven by an electric motor and convert mechanical energy into hydraulic energy, a level sensor that can monitor the liquid level and provide a low oil level alarm, a safety valve that can realize an overpressure relief function, a contamination indicator that can monitor oil contamination, an oil filter that can filter oil, a hydraulic self-sealing valve and an oil observation window that can realize a maintenance function. The redundancy conversion device includes a solenoid valve that can automatically cut off the power source, a solenoid valve that can cut off the oil circuit, a pressure sensor that can realize pressure monitoring and alarm functions, and a one-way valve that can realize oil flow function.

[0042] Further, in step five, based on the physical function model of the hydraulic system of Rhapsody, a hydraulic system physical performance model based on AMESim is built, which consists of a main hydraulic power unit, a backup power unit, a redundancy conversion device and a main tail rotor servo actuator cylinder, wherein the system oil is set to No. 15 aviation hydraulic oil, the medium temperature is -55 to +135°C, and the ambient temperature is -55 to +70°C; the rated working pressure of the main hydraulic power unit is 28MPa, the rated flow is 50L / min, the total effective volume of the oil tank is 4.5L, and the low oil level alarm oil level is 2L; the rated working pressure of the backup hydraulic power unit is 28MPa, the rated flow is 50L / min, the total effective volume of the oil tank is 4.5L, the low oil level alarm oil level is 2L, and the voltage is 28VDC; the switching response time of the redundancy conversion device is not more than 0.2s, and the main tail rotor servo actuator cylinder adopts a single actuator cylinder controlled by PID, with a load of 5000N;

[0043] Based on the sequence diagram, the cockpit display panel of the hydraulic system is simulated in AMESim, including the main hydraulic pressure display, backup hydraulic pressure display, main hydraulic system oil temperature display, backup hydraulic system oil temperature display, main hydraulic system fluid level display, and backup hydraulic system fluid level display.

[0044] Furthermore, in step six, a CAT IA-based three-dimensional visual model of the main tail rotor dynamics is constructed, and according to the actual installation status of each component of the main tail rotor, respective kinematic pairs are established to represent the assembly position and motion relationship of the main tail rotor; a rotary pair drive is added to drive the main tail rotor rotary shaft drive, and a force unit is added to increase the drive damping; control input and output variables and nodes are added as the interactive data interface between AMESim and CAT IA, and AMESim inputs the hydraulic resultant force of the main tail rotor servo actuator to CAT IA, and CAT IA outputs the velocity and displacement of the main tail rotor servo actuator to AMESim to represent the relationship between the hydraulic system and the main tail rotor.

[0045] Furthermore, in step seven, the data interaction between the grid models is shown in the following table:

[0046]

[0047]

[0048] In summary, the beneficial effects of the present invention are as follows:

[0049] The present invention relates to a multidisciplinary helicopter hydraulic system joint simulation method, which realizes the work of demand confirmation, simulation analysis verification and design iteration in the forward design of the hydraulic system through the application of simulation technology between physical function models, physical performance models and three-dimensional visual models. On the other hand, it can intuitively display the state changes of the hydraulic system during operation and the execution status of system users, and can realize system logic and performance verification in the early stage of hydraulic system design to avoid the high cost caused by later changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a use case diagram.

[0051] Figure 2 For the activity diagram.

[0052] Figure 3 It is a sequence diagram.

[0053] Figure 4 It is a black box state diagram.

[0054] Figure 5 It is a white box state diagram.

[0055] Figure 6 This is the simulation result diagram.

[0056] Figure 7 This is the joint simulation flow chart. DETAILED DESCRIPTION

[0057] A multidisciplinary joint simulation method for helicopter hydraulic systems is implemented through demand development software, performance simulation software, and dynamics simulation software. According to the definition of the helicopter hydraulic system, the system demand analysis is carried out; the functional logic model of the helicopter hydraulic system based on Rhapsody is built; through functional analysis, the hydraulic system activity diagram, sequence diagram, and black box state diagram are determined, and design synthesis is carried out to determine the hydraulic system logic architecture model, and verify whether the system logic meets expectations; a hydraulic system performance simulation model based on AMESim is built, performance parameters are set, and simulation verification is carried out; according to the motion relationship of the helicopter main rotor and tail rotor, the respective kinematic pairs are established, the assembly position and motion relationship settings are completed, and a main tail rotor dynamic three-dimensional visual model based on CAT IA is built; the data interaction interface of Rhapsody, AMESim, and CAT IA is set; simulation parameters are set, simulation is carried out, simulation results are determined, and hydraulic system demand verification is realized.

[0058] The specific steps include:

[0059] Step 1: Obtain hydraulic system requirements;

[0060] First, according to the definition of the whole life cycle stage of the helicopter, including project feasibility study, (overall) scheme design, detailed engineering design, scientific research adjustment flight test, identification flight test, use / support and other six stages, identify the main participants in each stage, including the military, pilots, ground crew, aircrew support personnel, designer team, process manufacturing team, test team, finished product supplier and other stakeholders, and obtain their needs at different stages; extract the relevant clauses applicable to the hydraulic system in the top-level documents and standards of the project, and form items; obtain similar product design experience / fault information, and analyze previous faults, extract requirements that are easier to optimize product functions and improve performance, and form items; integrate the requirements obtained from the above three ways, including trade-offs, merging, and sorting, and finally obtain the hydraulic system requirements;

[0061] Step 2: Conduct hydraulic system demand analysis and obtain a hydraulic system use case diagram to represent external interface relationships;

[0062] According to the above hydraulic system requirements, use cases are created in Rhapsody to determine the functions of the hydraulic system, namely, providing hydraulic energy, managing electromechanical information flow and ground maintenance of the system. The relationship between the above stakeholders and the three functions is described to obtain a use case diagram, which expresses the boundaries of the hydraulic system, as well as the interaction and interfaces with the outside world (i.e., pilots, display systems, main reducers, power systems, flight control systems, flight management systems, ground crews, hydraulic oil trucks, wheels, etc.), namely, the hydraulic system has mechanical interfaces with the main reducer, power system, and flight control system, electronic communication interactions with the display system and flight management system, and human-machine control interactions with pilots and ground crews.

[0063] Step 3: Perform functional analysis on each of the above use cases through activity diagrams, sequence diagrams, and black box state diagrams to represent the internal relationships of the system and refine the external interface relationships;

[0064] Based on the use case diagram, the three functions of the hydraulic system are divided into multiple activities and operations, and the activity diagram is used to represent the logical relationship and workflow between each activity, which is used to represent the internal relationship of the system. The functional logic of "providing pressure energy" is described as follows: when the hydraulic system is powered on, the system is in the power-on state; the main reducer is started, and the mechanical energy is converted into the pressure energy of the hydraulic system; the high-pressure oil is filtered by the storage device and then provided to each user; the return oil connected to the user is returned to the hydraulic storage device through the return oil filter after actuation; when the system pressure is lower than the specified pressure value, the backup hydraulic source is switched to supply pressure; when the system pressure is higher than the specified value, the pressure is relieved through the pressure relief device. The functional logic of "managing electromechanical information flow" is described as follows: when the hydraulic system is working, the pressure in the system is monitored and the pressure data is transmitted to the flight control system in real time. When the pressure is lower than the specified value, a low pressure alarm is provided to the pilot; the liquid level in the system is monitored and the liquid level data is transmitted to the flight control system in real time. When the system liquid level is lower than the specified value, a low liquid level alarm is provided to the pilot, and unimportant users with high oil leakage rates are cut off; the oil temperature in the system is monitored and the oil temperature data is transmitted to the flight control system in real time. When the system oil temperature is higher than the specified value, a high oil temperature alarm is provided to the pilot; the oil contamination level in the system is monitored and the pressure difference data is transmitted to the flight control system in real time. When the pressure difference data is higher than the specified value, an oil contamination alarm is provided to the pilot and ground crew. The functional logic of "system ground maintenance" is described as follows: on the ground, ground staff replenish pressure to the hydraulic system manually or automatically; on the ground, ground staff perform power-assisted checks on user actions through the ground hydraulic oil source; on the ground, ground staff replenish oil to the onboard storage device through the ground hydraulic oil source or manually; on the ground, ground staff inspect and repair the hydraulic system.

[0065] Based on the activity diagram, under the external environments such as natural environment, mechanical environment, electromagnetic environment described in the top-level file of the project in the hydraulic system requirements, as well as the constraints of system safety, maintainability, reliability, testability, security and weight, the interaction between the hydraulic system and the outside world and the dynamic sequence between the activities in the activity diagram are analyzed in each working scenario of the entire flight mission profile of the helicopter (including hangar, towing and taxiing, take-off, climb, cruise, combat and landing), and a sequence diagram is obtained to represent the behavioral sequence of the use case. During the climb / cruise / combat phases, under the constraints of natural environment, mechanical environment, electromagnetic environment, system safety and reliability, a sequence diagram of pressure supply scenarios and fault scenarios for users such as the flight control system is drawn. That is, when the power supply system powers on the hydraulic system, the main reducer provides mechanical energy to the hydraulic system, and the pilot controls the helicopter through the flight control stick. The hydraulic system provides high-pressure oil at a certain pressure to provide control assistance. The hydraulic system feeds back pressure data, liquid level data, temperature data, and pressure difference data to the flight control system and display system. When the liquid level is lower than the specified value, the system feeds back the fault status to the flight control system and the display system. The pilot can receive an alarm prompt in the display system, and the control unit in the system automatically cuts off unimportant users with high leakage rates and prompts the pilot. During the hangar stage, under the constraints of the system's storage environment, reliability, maintainability and security, draw a sequence diagram of the ground pressure replenishment, power assistance inspection, oil replenishment and maintenance scenarios in the "system ground maintenance" function; during the traction and taxiing stage, under the electromagnetic environment and reliability indicators, draw a sequence diagram of the wheel braking, tail wheel unlocking pressure supply scenarios and fault scenarios; during the take-off / landing stage, under the constraints of the natural environment, mechanical environment, electromagnetic environment, system safety and reliability, draw a sequence diagram of the flight control system pressure supply scenarios and fault scenarios.

[0066] Based on the activity diagram and sequence diagram, according to the three functions of the hydraulic system, the working states of each activity in different scenarios in the sequence diagram are comprehensively represented to obtain the black box state diagram, which integrates the information of the activity diagram and the sequence diagram and is used to represent the working state of the system, the transition between states and the execution operation. The working states in the black box state diagram of "providing pressure energy" include normal pressure supply state, auxiliary pressure supply state, overpressure state, flight control pressure supply state, wheel brake pressure supply state, tail wheel unlocking pressure supply state and landing gear pressure supply state; the working states in the black box state diagram of "managing electromechanical information flow" include pressure monitoring state, liquid level monitoring state, temperature monitoring state, pollution monitoring state and alarm state, among which the alarm state includes low pressure alarm state, low liquid level alarm state, overtemperature alarm state and pollution alarm state; the working states in the black box state diagram of "system ground maintenance" include charging state, ground refueling state, ground flight assist inspection state and ground equipment maintenance state.

[0067] Step 4: Based on functional analysis, allocate the system functions in the black box state diagram to each subsystem, select the best physical implementation form of each subsystem function, and conduct system design synthesis, merge the functional similar items in each subsystem, and comprehensively consider the system safety, maintainability, reliability, testability, security and weight constraints to obtain the white box state diagram, operate the status of each subsystem to verify the previous requirements, and build a physical functional model of the hydraulic system based on Rhapsody, which consists of a main hydraulic power unit, a backup hydraulic power unit, and a redundancy conversion device. The main hydraulic power unit includes a hydraulic oil tank that can realize the oil storage function, a hydraulic pump that can convert mechanical energy into hydraulic energy, a level sensor that can monitor the liquid level and provide a low oil level alarm, and a hydraulic system that can realize A safety valve with overpressure relief function, a contamination indicator for monitoring oil contamination, an oil filter for filtering oil, a hydraulic self-sealing valve and an oil observation window for maintenance function; the backup hydraulic power unit includes a hydraulic oil tank for storing oil, a hydraulic pump driven by an electric motor and converting mechanical energy into hydraulic energy, a level sensor for monitoring the liquid level and providing a low oil level alarm, a safety valve for overpressure relief function, a contamination indicator for monitoring oil contamination, an oil filter for filtering oil, a hydraulic self-sealing valve and an oil observation window for maintenance function; the redundancy conversion device includes a solenoid valve for automatically cutting off the power source, a solenoid valve for cutting off the oil circuit, a pressure sensor for pressure monitoring and alarm functions, and a one-way valve for oil flow function.

[0068] Step 5: Based on the physical function model of the hydraulic system in Rhapsody, a physical performance model of the hydraulic system based on AMESim is constructed, which consists of a main hydraulic power unit, a backup power unit, a redundancy conversion device and a main tail rotor servo actuator. The system oil is set to No. 15 aviation hydraulic oil, the medium temperature is -55 to +135°C, and the ambient temperature is -55 to +70°C; the rated working pressure of the main hydraulic power unit is 28MPa, the rated flow rate is 50L / min, the total effective volume of the oil tank is 4.5L, and the low oil level alarm oil level is 2L; the rated working pressure of the backup hydraulic power unit is 28MPa, the rated flow rate is 50L / min, the total effective volume of the oil tank is 4.5L, the low oil level alarm oil level is 2L, and the voltage is 28VDC; the switching response time of the redundancy conversion device is no more than 0.2s, and the main tail rotor servo actuator adopts a single actuator controlled by PID with a load of 5000N.

[0069] Based on the sequence diagram, the cockpit display panel of the hydraulic system is simulated in AMESim, including the main hydraulic pressure display, backup hydraulic pressure display, main hydraulic system oil temperature display, backup hydraulic system oil temperature display, main hydraulic system fluid level display, and backup hydraulic system fluid level display;

[0070] Step 6: Build a CAT IA-based three-dimensional visual model of the main tail rotor dynamics. According to the actual installation status of each component of the main tail rotor, establish their own kinematic pairs to represent the assembly position and motion relationship of the main tail rotor; add a rotary pair drive to drive the main tail rotor rotation axis drive, add a force unit, and increase the drive damping; add control input and output variables and nodes as the interactive data interface between AMESim and CAT IA. AMESim inputs the hydraulic force of the main tail rotor servo actuator to CAT IA, and CAT IA outputs the speed and displacement of the main tail rotor servo actuator to AMESim to represent the relationship between the hydraulic system and the main tail rotor.

[0071] Step 7: Combine the hydraulic system physical function model, the hydraulic system physical performance model and the three-dimensional visual model of the main tail rotor dynamics;

[0072] Specifically, the input and output boundaries and interaction data settings between each model are shown in the table below.

[0073] Table interactive data settings between models

[0074]

[0075] Step 8: Set simulation conditions and perform joint simulation.

[0076] Taking "low pressure in main hydraulic system" and "low oil level in main hydraulic system" as examples, joint simulation is carried out. The joint simulation time is set to 10 seconds. In the Rhapsody physical function model, the dynamic behavior of the hydraulic system is described, the hydraulic system requirements are verified, and the control signal is transmitted to the AMES im physical performance model. When the supply pressure of the main hydraulic power unit in the AMES im physical performance model drops below a certain pressure value, the pressure sensor uploads the pressure data to the Rhapsody physical function model. The Rhapsody physical function model gives a control signal as scheduled, and the backup hydraulic system pressure is controlled to increase to 21MPa in the AMES im physical performance model. The control unit in the system completes the switch as scheduled, and the main hydraulic system supply pressure and backup hydraulic system supply pressure values ​​are displayed on the AMES im cockpit display panel. The motion state of the main tail rotor servo can be seen in the CAT IA main tail rotor dynamics three-dimensional visual model. This fault has no effect on it, and the autonomous handling function of the "low pressure in main system" fault is realized. In the AMESim physical performance model, it is set that the main hydraulic system leaks oil, the oil level in the tank decreases, and the low oil level alarm is triggered. The oil level sensor transmits the data to the Rhapsody physical function model. The Rhapsody physical function model gives a control signal as predetermined. In the AMESim physical performance model, the tail rotor cut-off valve is controlled to cut off the tail rotor pressure supply. The main hydraulic system tank oil level value is displayed on the AMESim cockpit display panel. In the CAT IA main tail rotor dynamics three-dimensional visual model, it can be seen that the tail rotor is not working, thereby realizing the autonomous handling function in the event of a "low oil level in the main hydraulic system" fault.

Claims

1. A multi-disciplinary helicopter hydraulic system joint simulation method, characterized by: Here are the steps: Step 1: Obtain hydraulic system requirements; Step 2: Analyze the requirements of the hydraulic system and obtain a hydraulic system use case diagram to represent the external interface relationship; Step 3: Perform functional analysis on each of the above use cases to obtain activity diagrams, sequence diagrams, and black box state diagrams to represent the internal relationships of the system and refine the docking interface relationships; Step 4: Based on the activity diagram, sequence diagram, and black box state diagram, perform system design synthesis to obtain a white box state diagram, which is used to represent the specific physical implementation form of the system and build a physical function model of the hydraulic system based on Rhapsody; Step 5: Based on the physical function model of the hydraulic system in Rhapsody, build the physical performance model of the hydraulic system based on AMESim; based on the sequence diagram, simulate the cockpit display panel of the hydraulic system in AMESim; Step 6: Build a CATIA-based 3D visual model of the main tail rotor dynamics to represent the assembly position and motion relationship of the main tail rotor, as well as the relationship between the hydraulic system and the main tail rotor; Step 7: Combine the hydraulic system physical function model, the hydraulic system physical performance model and the main tail rotor dynamics three-dimensional visual model; Step 8: Set simulation conditions and perform joint simulation.

2. The method according to claim 1, characterized in that: In step 1, the process of obtaining the hydraulic system requirements is as follows: According to the definition of the helicopter's life cycle stages, identify the participants in each stage, including the military, pilots, ground crew, aircrew support personnel, design team, process manufacturing team, test team, and finished product suppliers, and obtain the needs of participants at different stages; Extract relevant clauses applicable to hydraulic systems from top-level project documents and standards to form requirement items; Obtain similar product design experience / failure information, analyze previous failures, extract requirements that are easy to optimize product functions and improve performance, and form requirement items; The requirements obtained from the above three methods are integrated, including selection, merging and sorting, to finally obtain the hydraulic system requirements.

3. The method according to claim 2, characterized in that: In step 2, the process is as follows: According to the requirements of the hydraulic system, use cases are created in Rhapsody to determine the functions of the hydraulic system, provide hydraulic energy, manage electromechanical information flow and ground maintenance of the system, describe the relationship between all participants and the three functions, and obtain a use case diagram to express the boundaries of the hydraulic system, as well as its interaction with the outside world and its interfaces.

4. The method according to claim 3, characterized in that: In step three, the process of obtaining the activity diagram based on the use case diagram is as follows: Based on the use case diagram, the three functions of the hydraulic system are divided into multiple activities and operations. The activity diagram is used to represent the logical relationship and workflow between the activities, which is used to represent the internal relationship of the system.

5. The method according to claim 4, characterized in that: In step 3, the process of obtaining the sequence diagram based on the activity diagram is as follows: Based on the activity diagram, under the natural environment, mechanical environment, electromagnetic environment, and system safety, maintainability, reliability, testability, security, and weight constraints described in the top-level project file in the hydraulic system requirements, the interaction between the hydraulic system and the outside world in each working scenario of the entire flight mission profile of the helicopter and the dynamic sequence between each activity in the activity diagram are analyzed to obtain a sequence diagram that represents the behavioral sequence of the use case.

6. The method according to claim 5, characterized in that: In step 3, the process of obtaining the black box state diagram based on the activity diagram and sequence diagram is as follows: Based on the activity diagram and sequence diagram, according to the three functions of the hydraulic system, the working states of each activity in different scenarios in the sequence diagram are comprehensively represented to obtain the black box state diagram, which combines the information of the activity diagram and sequence diagram to represent the working state of the system, the transition between states and the execution operation.

7. The method according to claim 6, characterized in that: In step 4, the system functions in the black box state diagram are allocated to each subsystem, the best physical implementation form of each subsystem function is selected, and the system design synthesis is performed to merge the functional similar items in each subsystem, and the system safety, maintainability, reliability, testability, security and weight constraints are comprehensively considered to obtain the white box state diagram; The status of each subsystem is operated to verify the previous requirements, and a physical functional model of the hydraulic system based on Rhapsody is built, which consists of a main hydraulic power unit, a backup hydraulic power unit, and a redundancy conversion device.

8. The method according to claim 7, characterized in that: In step 5, based on the physical function model of the hydraulic system of Rhapsody, a hydraulic system physical performance model based on AMESim is constructed, which consists of a main hydraulic power unit, a backup power unit, a redundancy conversion device, and a main tail rotor rudder actuator. Based on the sequence diagram, the cockpit display panel of the hydraulic system is simulated in AMESim, including the main hydraulic pressure display, backup hydraulic pressure display, main hydraulic system oil temperature display, backup hydraulic system oil temperature display, main hydraulic system fluid level display, and backup hydraulic system fluid level display.

9. The method according to claim 8, characterized in that: In step six, a CATIA-based three-dimensional visual model of the main tail rotor dynamics is built. According to the actual installation status of each component of the main tail rotor, their respective kinematic pairs are established to represent the assembly position and motion relationship of the main tail rotor; a rotary pair drive is added to drive the main tail rotor rotation axis drive, and a force unit is added to increase the drive damping; control input and output variables and nodes are added as the interactive data interface between AMESim and CATIA. AMESim inputs the hydraulic force of the main tail rotor servo actuator to CATIA, and CATIA outputs the velocity and displacement of the main tail rotor servo actuator to AMESim to represent the relationship between the hydraulic system and the main tail rotor.

10. The method according to claim 9, characterized in that: In step 7, the data interaction between the grid models is shown in the following table:

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