A multi-disciplinary based helicopter hydraulic system co-simulation method

Abstract

The application belongs to the technical field of hydraulic systems, and discloses a helicopter hydraulic system joint simulation method based on multi-discipline, wherein step one is to acquire hydraulic system demand; step two is to analyze the hydraulic system demand to obtain a hydraulic system use case diagram; step three is to perform function analysis to obtain an activity diagram, a sequence diagram and a black box state diagram; step four is to perform system design synthesis based on the function analysis to obtain a white box state diagram and build a hydraulic system function logic model based on Rhapsody; step five is to build a hydraulic system physical performance model based on AMESim based on the hydraulic system physical function model based on Rhapsody; the cabin display panel of the hydraulic system is simulated in AMESim based on the sequence diagram; step six is to build a main tail rotor dynamics three-dimensional visual model based on CAT IA; step seven is to combine the hydraulic system function logic model, the complete hydraulic system physical prototype model and the main tail rotor dynamics three-dimensional visual model; and step eight is to set simulation conditions and perform joint simulation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydraulic systems, and particularly relates to a helicopter hydraulic system joint simulation method based on multi-disciplines. BACKGROUND

[0002] At present, the helicopter hydraulic system design adopts a model-based system engineering positive design method, but there are still some deficiencies in actual application.

[0003] 1. The transfer between the functional logic architecture obtained by top-down demand development and demand definition and the physical architecture after design synthesis can only be manually converted, lacks corresponding automatic tools, and the physical function model and the physical performance model are irrelevant and cannot be verified accordingly.

[0004] 2. At present, the hydraulic system simulation is single, and only the performance simulation verification of important parameters in the system physical architecture design can be realized, the correctness of the logic of the system cannot be verified, and the influence of the change of the hydraulic system on each user cannot be intuitively displayed. SUMMARY

[0005] The application aims to provide a helicopter hydraulic system joint simulation method based on multi-disciplines, which realizes demand confirmation, simulation analysis and verification, and design iteration in the positive design of the hydraulic system through the simulation technology application among the physical function model, the physical performance model and the three-dimensional visual model, and on the other hand, can intuitively display the state change in the running process of the hydraulic system and the execution of the system user, can realize the logic and performance verification of the system in the early stage of the hydraulic system design, and avoid the large cost caused by the later change.

[0006] TECHNICAL SCHEME

[0007] A helicopter hydraulic system joint simulation method based on multi-disciplines, steps are as follows:

[0008] Step 1: Obtain the hydraulic system demand;

[0009] Step 2: Analyze the hydraulic system demand to obtain a hydraulic system use case diagram for representing the external interface relationship;

[0010] Step 3: Perform function analysis on each use case to obtain an activity diagram, a sequence diagram and a black box state diagram for representing the internal relationship of the system and refining the interface relationship;

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

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

[0013] Step six: build the main tail rotor dynamics three-dimensional view model based on CAT IA, which is used to represent the assembly position and motion relationship of the main tail rotor, and the relationship between the hydraulic system and the main tail rotor;

[0014] Step seven: combine the hydraulic system physical function model, the hydraulic system physical performance model and the main tail rotor dynamics three-dimensional view model;

[0015] Step eight: set the simulation conditions and perform the joint simulation.

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

[0017] According to the definition of the whole life cycle stage of the helicopter, identify the participants in each stage, including the military, pilots, ground personnel, air support personnel, designer team, process manufacturing team, test team, finished product supplier, and obtain the requirements of the participants in different stages;

[0018] Extract the relevant provisions in the project top-level file and standards applicable to the hydraulic system to form the requirement items;

[0019] Obtain similar product design experience / fault information, analyze past failures, extract requirements that are prone to product function optimization and performance improvement, and form requirement items;

[0020] Integrate the requirements obtained through the above three approaches, including selection, combination, and sorting, to finally obtain the hydraulic system requirements.

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

[0022] According to the hydraulic system requirements, create use cases in Rhapsody, determine the functions of the hydraulic system, provide hydraulic energy, manage mechanical and electrical information flow and system ground maintenance, describe the relationship between all participants and the three functions, obtain the use case diagram, express the boundary of the hydraulic system, and the interaction with the outside world and the interface.

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

[0024] Based on the use case diagram, three functions of the hydraulic system are divided into multiple activities and operations, and the logical relationship and workflow between each activity are represented by activity diagram, which is used to represent the internal relationship of the system. The logical description of the function of "providing pressure energy" is as follows: when the hydraulic system is connected to the power supply, the system is in the power-on state; the main reducer starts, 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 provided to each user; the return oil of the connected user is returned to the hydraulic storage device after actuation; when the system pressure is lower than the specified pressure value, the backup hydraulic source is switched to provide pressure; when the system pressure is higher than the specified value, the pressure relief device is used for pressure relief;

[0025] The logical description of the function of "managing mechanical and electrical information flow" is as follows: when the hydraulic system is working, the pressure in the system is monitored and the pressure data is transmitted to the flight tube system in real time, and when the pressure is lower than the specified value, the pilot is provided with a low pressure alarm; the liquid level in the system is monitored and the liquid level data is transmitted to the flight tube system in real time, and when the system liquid level is lower than the specified value, the pilot is provided with a low liquid level alarm and the non-essential and high oil leakage rate users are cut off; the oil temperature in the system is monitored and the oil temperature data is transmitted to the flight tube system in real time, and when the system oil temperature is higher than the specified value, the pilot is provided with a high oil temperature alarm; the oil pollution degree in the system is monitored and the pressure difference data is transmitted to the flight tube system in real time, and when the pressure difference data is higher than the specified value, the pilot and ground crew are provided with an oil pollution alarm;

[0026] The logical description of the function of "system ground maintenance" is as follows: on the ground, the ground crew replenishes the pressure of the hydraulic system by manual or automatic means; on the ground, the ground crew checks the power assistance of user action by ground hydraulic oil source; on the ground, the ground crew replenishes the oil in the on-board storage device by ground hydraulic oil source or manual means; on the ground, the ground crew overhauls the hydraulic system.

[0027] Further, in step three, 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 constraint conditions described in the top-level file of the project in the hydraulic system demand, the interaction between the hydraulic system and the outside world and the dynamic sequence between each activity in the activity diagram are analyzed under each working scene of the whole flight mission profile of the helicopter, and the sequence diagram is obtained to represent the behavior sequence of the use case;

[0029] In the climbing / cruising / fighting stage, under the constraints of natural environment, mechanical environment, electromagnetic environment, system safety, reliability, the sequence diagram of user pressure supply scene and failure scene is drawn. When the power supply system is powered on, the main reducer provides mechanical energy for the hydraulic system. The pilot controls the helicopter through the flight control stick, and the hydraulic system provides a certain pressure of high-pressure oil to provide steering assistance. The hydraulic system feeds back pressure data, liquid level data, temperature data, and pressure difference data to the flight tube system and display system. When the liquid level is lower than the specified value, the system feeds back the failure state to the flight tube system and display system. The pilot receives an alarm prompt in the display system, and the control unit in the system automatically cuts off the non-essential and high leakage users and prompts the pilot;

[0030] In the hangar stage, under the constraints of the storage environment, reliability, maintainability and supportability of the system, the sequence diagram of the ground pressure compensation, power assistance check, oil replenishment and maintenance scene in the "system ground maintenance" function is drawn.

[0031] In the taxiing stage, under the constraints of electromagnetic environment and reliability index, the sequence diagram of wheel brake, tail wheel unlocking pressure supply scene and failure scene is drawn.

[0032] In the take-off / landing stage, under the constraints of natural environment, mechanical environment, electromagnetic environment, system safety, reliability, the sequence diagram of flight control system pressure supply scene and failure scene is drawn.

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

[0034] Based on the activity diagram and the sequence diagram, the working states of each activity in different scenes in the sequence diagram are comprehensively represented according to the three functions of the hydraulic system, and the black box state diagram is obtained, which collects 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.

[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, wherein 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 state diagram of "system ground maintenance" include pressure charging state, ground oiling state, ground flight power assistance check state, and ground equipment maintenance state.

[0038] Further, in step four, 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, the function homologous items in each subsystem are combined, and the system safety, maintainability, reliability, testability, supportability and weight constraint conditions are comprehensively considered to obtain a white box state diagram;

[0039] The state operation of each subsystem is implemented to verify the early-stage requirements, and a physical function model of the hydraulic system based on Rhapsody is built, which is composed 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 realizing oil storage, a hydraulic pump capable of converting mechanical energy into hydraulic energy, a liquid level sensor capable of monitoring the liquid level and providing low oil level alarm, a safety valve capable of realizing overpressure relief, a contamination indicator capable of realizing oil pollution monitoring, an oil filter capable of filtering oil, a hydraulic self-sealing valve capable of realizing maintenance function, and an oil observation window.

[0041] The backup hydraulic power unit includes a hydraulic oil tank capable of realizing oil storage, a hydraulic pump capable of converting mechanical energy into hydraulic energy driven by a motor, a liquid level sensor capable of monitoring the liquid level and providing low oil level alarm, a safety valve capable of realizing overpressure relief, a contamination indicator capable of realizing oil pollution monitoring, an oil filter capable of filtering oil, a hydraulic self-sealing valve capable of realizing maintenance function, and an oil observation window. The redundancy conversion device includes an electromagnetic valve capable of automatically cutting off the power source, an electromagnetic valve capable of realizing oil path cutting, a pressure sensor capable of realizing pressure monitoring and alarm function, and a one-way valve capable of realizing oil channel flow function.

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

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

[0044] Further, in step six, a CAT IA-based main tail rotor dynamics three-dimensional visual model is built, and according to the actual installation state of each component of the main tail rotor, a respective motion pair is 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 rotating shaft drive, a force unit is added to increase the driving damping; control input and output variables and nodes are added as the interactive data interface between AMESim and CAT IA, the hydraulic force of the main tail rotor steering cylinder is input from AMESim to CAT IA, and the speed and displacement of the main tail rotor steering cylinder are output from CAT IA to AMESim, which are used to represent the mutual relationship between the hydraulic system and the main tail rotor.

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

[0046]

[0047]

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

[0049] The helicopter hydraulic system joint simulation method based on multi-discipline relates to a kind of simulation technology application between physical function model, physical performance model and three-dimensional visual model, realizes demand confirmation, simulation analysis verification and design iteration etc. in hydraulic system forward design, on the other hand, the state change in the running process of hydraulic system can be visually displayed, and system user executes situation, can realize system logic and performance verification in the early stage of hydraulic system design, avoid the great cost brought by later change. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 It is use case diagram.

[0051] Figure 2 It is activity diagram.

[0052] Figure 3 It is sequence diagram.

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

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

[0055] Figure 6 It is simulation result diagram.

[0056] Figure 7 A joint simulation flow chart is shown. DETAILED DESCRIPTION

[0057] A multi-disciplinary helicopter hydraulic system joint simulation method is realized by developing software, performance simulation software and dynamics simulation software. According to the definition of the helicopter hydraulic system, the system requirement analysis is carried out; the function logic model of the helicopter hydraulic system based on Rhapsody is built; through function analysis, the activity diagram, sequence diagram and black box state diagram of the hydraulic system are determined, and design synthesis is carried out to determine the logical architecture model of the hydraulic system, and whether the system logic meets the expectation is verified; the hydraulic system performance simulation model based on AMESim is built, the performance parameters are set, and the simulation verification is carried out; according to the motion relationship of the main rotor and tail rotor of the helicopter, the respective kinematic pairs are established, the assembly position and motion relationship are set, and the main tail rotor dynamics three-dimensional visual model based on CAT IA is built; the data interaction interface of Rhapsody, AMESim and CAT IA is set; the simulation parameters are set, the simulation is carried out, the simulation result is determined, and the hydraulic system requirement verification is realized.

[0058] Specifically, the following steps are included:

[0059] Step one: obtaining the hydraulic system requirement;

[0060] Firstly, according to the definition of the whole life cycle stage of the helicopter, including project demonstration, (general) scheme design, detailed engineering design, scientific research adjustment flight, identification flight, use / safeguard, etc. six stages, the main participants of each stage are identified, including the military, pilots, ground personnel, air support personnel, designer team, process manufacturing team, test team, product supplier and other stakeholders, the requirements of different stages are obtained; the relevant provisions suitable for the hydraulic system in the project top-level file and standards are extracted, and the items are formed; the design experience / fault information of similar products is obtained, and the past faults are analyzed, the requirements which are more easy to optimize product function and improve performance are extracted, and the items are formed; the requirements obtained by the above three ways are synthesized, including selection, combination, sorting, and finally the hydraulic system requirement is obtained;

[0061] Step two: hydraulic system requirement analysis is carried out, and the hydraulic system use case diagram is obtained for representing the external interface relationship;

[0062] According to the above hydraulic system requirements, use cases are created in Rhapsody to determine the functions of the hydraulic system, i.e. providing hydraulic energy, managing the electromechanical information flow and system ground maintenance, to describe the relationship between the above stakeholders and the three functions, to obtain the use case diagram, to express the boundary of the hydraulic system, and to interact with the outside world (i.e. the pilot, the display system, the main reducer, the power supply system, the flight control system, the flight tube system, the ground crew, the hydraulic oil truck, the machine wheel, etc.) and the interface possessed, i.e. the hydraulic system has a mechanical interface with the main reducer, the power supply system and the flight control system, an electronic communication interaction with the display system and the flight tube system, and a human-computer operation interaction with the pilot and the ground crew.

[0063] Step three: function analysis of the above-mentioned use cases is performed through activity diagrams, sequence diagrams and black box state diagrams to represent the internal relationship of the system and to refine the external interface relationship.

[0064] Based on the use case diagram, the three functions of the hydraulic system are divided into multiple activities and operations, and the logical relationship and workflow between the activities are represented by activity diagrams to represent the internal relationship of the system. The logical description of the function of "providing pressure energy" is as follows: when the hydraulic system is connected to the power supply, the system is in the power-on state; the main reducer starts, 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 provided to each user; the return oil connected to the user is filtered and returned to the hydraulic storage device after actuation; when the system pressure is lower than the specified pressure value, the backup hydraulic source is switched to provide pressure; when the system pressure is higher than the specified value, the pressure relief device is used for pressure relief. The logical description of the function of "managing the electromechanical information flow" is as follows: when the hydraulic system is working, the pressure in the system is monitored and the pressure data is transmitted to the flight tube system in real time, and when the pressure is lower than the specified value, the pilot is provided with a low-pressure alarm; the liquid level in the system is monitored and the liquid level data is transmitted to the flight tube system in real time, and when the system liquid level is lower than the specified value, the pilot is provided with a low-liquid-level alarm and the non-essential users with high oil leakage rate are cut off; the oil temperature in the system is monitored and the oil temperature data is transmitted to the flight tube system in real time, and when the system oil temperature is higher than the specified value, the pilot is provided with a high-oil-temperature alarm; the oil pollution degree in the system is monitored and the pressure difference data is transmitted to the flight tube system in real time, and when the pressure difference data is higher than the specified value, the pilot and the ground crew are provided with an oil pollution alarm. The logical description of the function of "system ground maintenance" is as follows: on the ground, the ground crew provides pressure to the hydraulic system through manual or automatic means; on the ground, the ground crew checks the power assistance of user actions through the ground hydraulic oil source; on the ground, the ground crew replenishes the on-board storage device through the ground hydraulic oil source or manually; on the ground, the ground crew overhauls the hydraulic system.

[0065] Based on the activity diagram, under the external environment such as natural environment, mechanical environment, electromagnetic environment, and the constraint conditions of system safety, maintainability, reliability, testability, supportability and weight in the hydraulic system requirement, the interaction between the hydraulic system and the outside world and the dynamic sequence between the activities in the activity diagram are analyzed under each working scene (including hangar, towing, take-off, climbing, cruising, combat, landing) of the whole flight mission profile of the helicopter, and the sequence diagram is obtained to represent the behavior sequence of the use case. In the climbing / cruising / combating stage, under the constraints of natural environment, mechanical environment, electromagnetic environment, system safety and reliability, the sequence diagram of the user pressure supply scene and fault scene of the flight control system is drawn, that is, when the power supply system is powered on for the hydraulic system, the main reducer provides mechanical energy for the hydraulic system, the pilot realizes the helicopter control through the flight control stick, the hydraulic system provides a certain pressure of high-pressure oil to provide control assistance, the hydraulic system feeds back pressure data, liquid level data, temperature data and pressure difference data to the flight pipe system and display system, when the liquid level is lower than the specified value, the system feeds back the fault state to the flight pipe system and display system, the pilot can receive the alarm prompt in the display system, and the control unit in the system automatically cuts off the unimportant and large leakage rate users and prompts the pilot. In the hangar stage, under the constraints of the storage environment, reliability, maintainability and supportability of the system, the sequence diagram of the ground pressure compensation, assistance check, oil supplement and maintenance scene in the "system ground maintenance" function is drawn; in the towing stage, under the electromagnetic environment and reliability index, the sequence diagram of the wheel brake, tail wheel unlocking pressure supply scene and fault scene is drawn; in the take-off / landing stage, under the constraints of natural environment, mechanical environment, electromagnetic environment, system safety and reliability, the sequence diagram of the flight control system pressure supply scene and fault scene is drawn.

[0066] Based on the activity diagram and the sequence diagram, the working states of each activity in different scenes in the sequence diagram are comprehensively represented according to the three functions of the hydraulic system, and the black box state diagram is obtained, which collects the information of the activity diagram and the sequence diagram, and is used to represent the working state of the system, the conversion 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, wherein the alarm state includes low pressure alarm state, low liquid level alarm state, over temperature alarm state and pollution alarm state; the working states in the black box state diagram of "system ground maintenance" include pressure charging state, ground oil filling state, ground flight assistance check state and ground equipment maintenance state.

[0067] Step four: based on the function analysis, 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 carried out, the similar items in each subsystem are combined, and the constraints of system safety, maintainability, reliability, testability, supportability and weight are comprehensively considered, the white box state diagram is obtained, the state operation of each subsystem is realized, the verification of the early-stage demand is realized, the physical function model of the hydraulic system based on Rhapsody is built, which is composed of a main hydraulic power unit, a backup hydraulic power unit and a redundancy conversion device, wherein the main hydraulic power unit includes a hydraulic oil tank capable of realizing oil storage function, a hydraulic pump capable of realizing conversion of mechanical energy into hydraulic energy, a liquid level sensor capable of realizing monitoring of liquid level and providing low oil level alarm, a safety valve capable of realizing overpressure relief function, a contamination indicator capable of realizing oil pollution monitoring, an oil filter capable of realizing filtering of oil, a hydraulic self-sealing valve capable of realizing maintenance function and an oil observation window, the backup hydraulic power unit includes a hydraulic oil tank capable of realizing oil storage function, a hydraulic pump capable of realizing conversion of mechanical energy into hydraulic energy driven by a motor, a liquid level sensor capable of realizing monitoring of liquid level and providing low oil level alarm, a safety valve capable of realizing overpressure relief function, a contamination indicator capable of realizing oil pollution monitoring, an oil filter capable of realizing filtering of oil, a hydraulic self-sealing valve capable of realizing maintenance function and an oil observation window, and the redundancy conversion device includes an electromagnetic valve capable of realizing automatic cut-off of power source, an electromagnetic valve capable of realizing cut-off of oil way, a pressure sensor capable of realizing pressure monitoring and alarm function, and a check valve capable of realizing oil channel flow function.

[0068] Step five: based on the physical function model of the hydraulic system based on Rhapsody, the physical performance model of the hydraulic system based on AMESim is built, which is composed of a main hydraulic power unit, a backup power unit, a redundancy conversion device and a main tail rudder actuator cylinder, wherein the system oil is set to be No. 15 aviation hydraulic oil, the medium temperature is-55+135℃, and the environmental temperature is-55+70℃; the rated working pressure of the main hydraulic power unit is 28 MPa, the rated flow is 50 L / min, the effective total volume of the oil tank is 4.5 L, and the low oil level alarm oil surface is 2 L; the rated working pressure of the backup hydraulic power unit is 28 MPa, the rated flow is 50 L / min, the effective total volume of the oil tank is 4.5 L, the low oil level alarm oil surface is 2 L, and the voltage is 28 VDC; the switching response time of the redundancy conversion device is not greater than 0.2 s, the main tail rudder actuator cylinder adopts a single actuator cylinder controlled by PID, and the load is 5000 N.

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

[0070] Step six: build a three-dimensional visual model of the main tail rotor dynamics based on CAT IA, according to the actual installation state of each component of the main tail rotor, establish the kinematic pair respectively, used to represent the assembly position and motion relationship of the main tail rotor; add rotary pair drive, used to drive the main tail rotor rotating shaft drive, add force unit, increase the driving damping; add control input and output variables and nodes, as the interactive data interface of AMESim and CAT IA, input the hydraulic force of the main tail rotor steering engine actuator cylinder from AMESim to CAT IA, output the speed and displacement of the main tail rotor steering engine actuator cylinder from CAT IA to AMESim, used to represent the mutual relationship between the hydraulic system and the main tail rotor.

[0071] Step seven: 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 interactive data between each model are shown in the following table.

[0073] Table 1: Interactive data settings between models

[0074]

[0075] Step eight: set the simulation conditions and perform joint simulation.

[0076] Take "low pressure of main hydraulic system" and "low oil level of main hydraulic system" as examples, the co-simulation is carried out. Set the co-simulation time 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 AMESim physical performance model. When the main hydraulic power unit pressure in the AMESim physical performance model is reduced to below a certain pressure value, the pressure sensor uploads the pressure data to the Rhapsody physical function model, and the Rhapsody physical function model gives the control signal according to the pre-set. The backup hydraulic system pressure in the AMESim physical performance model is increased to 21 MPa, and the control unit in the system completes the switching according to the pre-set. The main hydraulic system pressure and backup hydraulic system pressure values are displayed on the AMESim cockpit display panel. In the CAT IA main tail rotor dynamics three-dimensional visual model, the motion state of the main tail rotor can be seen, and this fault has no effect on it, realizing the autonomous handling function when the "low pressure of main hydraulic system" fault occurs. In the AMESim physical performance model, set the main hydraulic system oil leakage, the oil tank oil level is reduced, and the low oil level alarm is triggered. The oil level sensor transmits the data to the Rhapsody physical function model, and the Rhapsody physical function model gives the control signal according to the pre-set. The tail rotor cut-off valve is controlled to cut off the tail rotor pressure in the AMESim physical performance model. The main hydraulic system oil 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 does not work, realizing the autonomous handling function when the "low oil level of main hydraulic system" fault occurs.

Claims

1. A method for multidisciplinary co-simulation of a helicopter hydraulic system, characterized in that: The steps are as follows: Step one: Obtain the hydraulic system requirements; Step two: Analyze the hydraulic system requirements to obtain a use case diagram for the hydraulic system to represent the external interface relationship; Step three: Perform a functional analysis of the use case diagram to obtain activity diagrams, sequence diagrams, and black box state diagrams to represent the internal relationship of the system and refine the interface relationship; Step four: Based on the activity diagrams, sequence diagrams, and black box state diagrams, 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 Rhapsody-based hydraulic system physical function model; Step five: Based on the Rhapsody-based hydraulic system physical function model, build an AMESim-based hydraulic system physical performance model; based on the sequence diagram, simulate the cockpit display panel of the hydraulic system in AMESim; Step six: Build a CATIA-based main and tail rotor dynamics three-dimensional visual model, establish the kinematic pairs of each component according to their actual installation state, and use them to represent the assembly position and motion relationship of the main and tail rotor; add a rotary pair drive to drive the main and tail rotor shaft, add a force unit to increase the driving damping; add control input and output variables and nodes as the data interface between AMESim and CATIA, input the hydraulic force of the main and tail rotor actuator cylinder from AMESim to CATIA, and output the speed and displacement of the main and tail rotor actuator cylinder from CATIA to AMESim, which is used to represent the mutual relationship between the hydraulic system and the main and tail rotor; Step seven: Combine the hydraulic system physical function model, the hydraulic system physical performance model, and the main and tail rotor dynamics three-dimensional visual model; Step eight: Set the simulation conditions and perform joint simulation.

2. The method of claim 1, wherein: In step one, the process of obtaining the hydraulic system requirements is as follows: Requirement one: According to the definition of the helicopter's life cycle stage, identify the participants in each stage, including the military, pilots, ground crew, aircrew support personnel, designer team, manufacturing team, test team, and product supplier, and obtain the requirements of the participants in different stages; Requirement two: Extract the relevant provisions in the project top-level file and standards applicable to the hydraulic system to form the requirement items; Requirement three: Obtain design experience, failure information, and analyze past failures to extract requirements that are easy to optimize product functionality and improve performance to form requirement items; Combine the above three requirements, including selection, merging, and sorting, to finally obtain the hydraulic system requirements.

3. The method of claim 2, wherein: In step two, the process is as follows: Based on the hydraulic system requirements, create a use case in Rhapsody to determine the functions of the hydraulic system, provide hydraulic energy, manage electrical and mechanical information flow, and system ground maintenance, describe the relationship between all participants and the three functions, obtain a use case diagram, and express the boundary of the hydraulic system, as well as the interaction with the outside world and the interface.

4. The method of claim 3, wherein: In step three, the process of obtaining an activity diagram based on the use case diagram is as follows: Based on the use case diagram, divide the three functions of the hydraulic system into multiple activities and operations, use activity diagrams to represent the logical relationship and workflow between activities, and use them to represent the internal relationship of the system.

5. The method of claim 4, wherein: In step three, the process of obtaining a sequence diagram based on the activity diagram is as follows: Based on the activity diagram, the interaction between the hydraulic system and the outside world and the dynamic sequence of each activity in the activity diagram are analyzed under the natural environment, mechanical environment, electromagnetic environment, and system safety, maintainability, reliability, testability, supportability, and weight constraints described in the project top-level file in the hydraulic system requirements. The sequence diagram is obtained to represent the behavior sequence of the use case.

6. The method of claim 5, wherein: In step three, the black box state diagram is obtained based on the activity diagram and the sequence diagram as follows: Based on the activity diagram and the sequence diagram, the activities in different scenarios in the sequence diagram are integrated to obtain the black box state diagram, which collects the information of the activity diagram and the sequence diagram and is used to represent the working state of the system, the conversion between states, and the execution operation.

7. The method of claim 6, wherein: In step four, 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 is integrated. The functions of the same kind in each subsystem are combined, and the system safety, maintainability, reliability, testability, supportability, and weight constraints are considered to obtain the white box state diagram. The state operation of each subsystem is implemented to verify the previous requirements, and the physical function model of the hydraulic system based on Rhapsody is built, which is composed of the main hydraulic power unit, the backup hydraulic power unit, and the redundancy conversion device.

8. The method of claim 7, wherein: In step five, the physical performance model of the hydraulic system based on AMESim is built based on the physical function model of the hydraulic system based on Rhapsody, which is composed of the main hydraulic power unit, the backup power unit, the redundancy conversion device, and the main tail rotor actuator cylinder. Based on the sequence diagram, the cockpit display panel of the hydraulic system is simulated in AMESim, including the main hydraulic pressure display, the backup hydraulic pressure display, the main hydraulic system oil temperature display, the backup hydraulic system oil temperature display, the main hydraulic system liquid level display, and the backup hydraulic system liquid level display.

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