CN110134025A - A real-time simulation system for a small distributed hypersonic vehicle - Google Patents

Abstract

The invention provides a real-time simulation system for a small-scale distributed hypersonic aircraft, which is composed of a main control module, a simulation module and a visual module. The system includes a human-computer interaction interface, and the user can change the relevant parameters of the aircraft at any time on the interface There is no need to interrupt the simulation, and it also contains a visual interface, the user can clearly see the flight status of the aircraft under the current parameters on this interface, which has the characteristics of simplicity, high real-time and visualization.

Description

A real-time simulation system for a small distributed hypersonic vehicle

technical field

The invention relates to the field of simulation, in particular to a design of a small-scale simulation platform for hypersonic aircraft, which combines Simulink to build a controller and aircraft model under the MATLAB environment, and combines VC++ and OpenGL development management platform and human-computer interaction interface to form a joint mobile Portable simulation platform, suitable for simulation and verification under online regulation.

Background technique

With the continuous development of science and technology, more and more attention has been paid to aircraft. Aircraft, especially unmanned aerial vehicles such as hypersonic vehicles, have played various roles in different fields and are widely used in agriculture, commerce, military, and national defense, and have irreplaceable value and potential. However, there are many factors affecting the performance of the aircraft, the high cost, and the characteristics of easy damage often restrict the development speed of the aircraft. The actual feasibility of the current achievements cannot be verified directly, and simulation has been widely used in the field of control. Using the simulation platform to simulate the feasibility of the achieved results has an incomparable advantage in actual flight tests. The computer simulation platform is economical, safe, not limited by the site and weather environment, controllable and repeatable. These characteristics make the simulation platform occupy an important position in the research of aircraft. Countries all over the world have attached great importance to the aircraft simulation platform and developed it as a key point. project.

In order to verify the performance of different design schemes, engineers usually use software such as MATLAB to conduct offline simulation verification, but this method has great limitations. We can only analyze the performance of design schemes through the data and images in the simulation results. But you cannot see the real-time flight status of the aircraft under the current parameters. Secondly, MATLAB simulation is an offline simulation. After the simulation starts, if some parameters of the system change, we can only wait for the current simulation to end, or stop the simulation directly, and restart after changing the parameters. We cannot get the system response when the parameters change. dynamic process. Furthermore, the simulation in the Simulink environment is not real-time simulation in the true sense, it changes the simulation time of the model to a certain extent.

In general, in the existing aircraft simulation methods, aircraft simulation can be divided into three categories according to different simulation model forms and different simulation methods, namely physical simulation, semi-physical simulation and full digital simulation. Simulation of aircraft, especially hypersonic aircraft, requires a large number of different types of resources. The higher the accuracy of the model, the more complex the structure, and the longer the calculation time. It is almost impossible to complete real-time simulation for this type of model in stand-alone simulation. At the same time, this simulation method requires the operator to have sufficient programming and simulation capabilities, and cannot change parameters in real time for debugging, which requires high requirements and is relatively cumbersome. At present, some good online real-time simulation systems are mostly expensive, or the technology is confidential, or it is a special system, which cannot be used by ordinary engineers. In addition, most existing simulation platforms do not have mobility, or have poor mobility, which cannot meet the practicality and flexibility requirements of simulation.

Considering the disadvantages of the existing simulation methods, including complex model establishment and discontinuous parameter adjustment process, it is impossible to observe the state of the aircraft intuitively in real time. Considering the disadvantages of existing simulation methods and simulation platforms, including complex model establishment, non-continuous parameter adjustment process, inability to intuitively observe the state of the aircraft in real time, and poor mobility.

Contents of the invention

In order to solve the problems existing in the prior art, the present invention will provide a design scheme of a real-time simulation platform for small mobile distributed aircraft. This program will give a design method to realize real-time simulation. At the same time, in view of the problem that online parameters cannot be adjusted during the simulation process, this program includes a human-computer interaction interface. Users can change the relevant parameters of the aircraft at any time on this interface without interrupting the simulation. ; The system also contains a visual interface, the user can clearly see the real-time flight status of the aircraft under the current parameters on this interface; so this program has the characteristics of simplicity, high real-time and visualization.

In view of the problems existing in the existing technology, this party adopts the following technical solutions to realize it:

A real-time simulation system for a small distributed hypersonic vehicle, consisting of a main control module, a simulation module and a visual module,

The main control module is the hub of the entire distributed simulation platform. It simulates the aircraft model in the Simulink environment, transmits data with the simulation module during the simulation process, and transmits the attitude data to the visual module. It also has the functions of controlling the simulation start-stop and storage Functions for simulating data;

The simulation module is equivalent to the controller of the aircraft. It runs the flight control program and server program that support the Simulink external mode. According to the aircraft attitude data and given parameters transmitted from the main control module, control instructions are given through calculation and sent to the main control module; Wherein, the simulation module includes a data receiving module, a real-time data display module, a data storage module, a data viewing module, a real-time curve drawing module and a human-computer interaction interface;

The visual module runs the visual software, is responsible for receiving the attitude data of the aircraft transmitted by the main control module in real time, and displays the real-time state of the aircraft in the form of animation, so that the user can observe the whole simulation process more intuitively, wherein: the visual module includes animation display Unit, visual display unit, data receiving and processing unit, aircraft model and scene model.

The present invention also comprises following steps to implement:

S1, the simulation module sets initial parameters;

S2, the main control module starts the simulation process;

2.1. RTW-based flight control program conversion;

2.2. Build a conversion communication network;

2.3. Real-time simulation processing;

S3, the simulation module receives the corresponding data and distributes different data processing modules to realize the human-computer interaction to the aircraft output data output and curve image process;

S4, the visual module receives corresponding data and displays the flight state of the aircraft in the form of animation;

S5, the simulation module realizes online parameter adjustment through the man-machine exchange interface, if the curve image in the simulation module and the state of the aircraft in the visual module meet the requirements, then end the simulation state; otherwise, return to step S2.

The main control module and the simulation module carry out data transmission based on the TCP/IP communication protocol, the main control module and the simulation module adopt the client/server mode, the client sends the attitude data of the aircraft model to the server, and the server receives the attitude data and sends the flight The control commands output by the control program are sent to the aircraft model, and the client and server codes are written by using C language SOCKET socket programming to realize the normal sending and receiving functions of data.

Beneficial effect

1. Considering the disadvantages of the existing simulation methods, including complex model establishment, non-continuous parameter adjustment process, and the inability to observe the state of the aircraft in real time intuitively; this invention will provide a design method for real-time simulation. At the same time, for the simulation For problems that cannot be adjusted during the process, this solution includes a human-computer interaction interface, where the user can change the relevant parameters of the aircraft at any time without interrupting the simulation; the solution also includes a visual interface, where the user can clearly see To the flight status of the aircraft under the current parameters; it has the characteristics of simplicity, high real-time and visualization.

2. When using simulation software such as MATLAB or a simulation platform for algorithm verification, the simulation results usually cannot be displayed in real time. If you want to modify the system parameters, you need to wait for the current simulation to end or stop the simulation before it can be realized, and the changed results cannot be displayed immediately. Therefore, it is difficult to reflect the real-time characteristics. For this reason, the purpose of the simulation platform invented is that if the system parameters need to be adjusted during the simulation, the changes can be made directly in the corresponding window of the simulation module, and the simulation can continue under the new parameters without a terminal, so that real-time observation To realize the change of simulation results caused by parameter changes, realize online parameter adjustment.

3. Most of the simulation time scales of the existing simulation platforms are far from the real system, but this platform can better approach the real system in terms of real-time performance; at the same time, the visual module of the platform can compare the flight status of the aircraft during the simulation process. It is displayed in real time, allowing users to understand the current status of the aircraft more intuitively.

Description of drawings

Fig. 1 is a flowchart of the present invention;

Fig. 2 is a schematic diagram of the interface layout of the simulation module of the present invention;

Figure 3 is the effect diagram of the data real-time display module;

Figure 4 Data view module effect diagram;

Fig. 5 The human-computer interaction interface of the simulation module;

Figure 6 Structural block diagram of the visual module;

Fig. 7 sketch map of aircraft model;

Figure 8 Process block diagram of animation

Fig. 9 distribution is a structural block diagram of the simulation system;

Figure 10 is a flow chart of the simulation software implementation of the visual module;

Detailed ways

The invention relates to an online real-time simulation method based on MATLAB. Taking a longitudinal model of a hypersonic aircraft as an example, the design method is introduced to realize the visualized online real-time simulation of the hypersonic aircraft.

As shown in Figure 1, the overall design of the simulation platform is given first. The distributed simulation platform consists of three modules, namely the main control module, the simulation module and the visual module.

The main control module is the hub of the entire distributed simulation platform. It simulates the aircraft model in the Simulink environment, transmits data with the simulation module during the simulation process, and transmits the attitude data to the visual module. It also has the functions of controlling the simulation start-stop and storage Functions for simulating data.

The simulation module is equivalent to the controller of the aircraft. It runs the flight control program and server program that support the Simulink external mode. According to the aircraft attitude data and given parameters transmitted from the main control module, control instructions are given through calculation and sent to the main control module.

The visual module runs the visual software, which is responsible for receiving the aircraft attitude data transmitted by the main control module in real time, and displays the real-time status of the aircraft in the form of animation, so that users can observe the whole simulation process more intuitively.

The present invention also comprises following steps to implement:

S1 (101), the simulation module sets initial parameters;

S2 (102), the main control module starts the simulation process;

2.1. RTW-based flight control program conversion;

2.2. Build a conversion communication network;

2.3. Real-time simulation processing;

S3 (103), the simulation module receives the corresponding data and distributes different data processing modules to realize the human-computer interaction to the aircraft output data output and curve image process;

S4 (104), the visual module receives corresponding data and displays the flight status of the aircraft in the form of animation;

S5 (105), the simulation module realizes online parameter adjustment through the man-machine exchange interface, if the curve image in the simulation module and the state of the aircraft in the visual module meet the requirements, then end the simulation state; otherwise return to step S2, wherein:

1. Main control module

According to the function of the main control module, its realization mainly includes three parts: the flight control program conversion based on RTW, the construction of communication network and the realization of real-time simulation.

(1) RTW-based flight control program conversion

In order to realize the conversion of the flight control program, the longitudinal model of the hypersonic vehicle is taken as an example, and the controller model is built in Simulink by combining the backstepping method and the dynamic inverse method.

The main function of the controller is to calculate the control instructions according to the state of the aircraft model during the simulation process, change the parameters of the controller in real time and send the control instructions output by the controller to the aircraft model, so that the aircraft model can make corresponding changes , and the use of RTW toolbox can realize the function of changing data online in real time. Therefore, save the model as flight_ctrl.mdl file, and use RTW to generate C code and external executable program for the controller model.

Before the conversion, in order to save the input aircraft model state quantity after the program simulation ends, first configure the output: open the scope module in the model, select the History tab in the settings, cancel the Limit data option, and select Save data to workspace option, change the variable name to All Data, and store it in Array format.

Next, set the generation options of C code and external programs, and open the Model ConfigurationParameters panel:

1. Select the Solver tab, change the termination time to inf, that is, infinite time, set the fixed step size to 0.05, and select the ode4 algorithm with higher precision, and save the settings;

2. Select the Code Generation tab, in the Target selection option, click the Browse button to open the system target file browser, change the system target file to the embedded real-time target, ie ert.tlc, click Apply, and return to the Code Generation option card, cancel the Generate code only option;

3. Select the MAT-file logging option to save the output data of the flight control program. When the program finishes running, the flight_ctrl.mat file will be generated. The rt_yout in this file saves the two output data of the flight control program, and the rt_tout saves the simulation time. In order to avoid data overflow, add the statement make_rtw OPTS=”-DDEFAULT_BUFFER_SIZE=102400” in the Make command window to make the memory allocation reach 102400Byte to ensure storage space, and add ert_default_tmf in the Template makefile window;

4. Select the Interface tab, select External mode in the Interface option, select tcpip in the Transportlayer option, so that the generated code supports external mode simulation, save the above settings, return to the CodeGeneration tab, and click the Build button. After successfully generating the code, the flight_ctrl.exe and ert_main.c files will appear. flight_ctrl.exe is the generated flight control program that supports external mode, and ert_main.c is the entry of the flight control program.

(2) Construction of communication network

As shown in Figure 9, the distributed aircraft simulation platform in the present invention carries out data transmission based on the TCP/IP communication protocol, the main control module and the simulation module adopt the client/server mode, and the client sends the attitude data of the aircraft model to the server, The server receives the attitude data and sends the control commands output by the flight control program to the aircraft model, and uses C language SOCKET socket programming to write the client and server codes to realize the normal sending and receiving functions of data:

First find and open the ert_main.c file generated in the previous step, find the rt_OneStep() function in the int_T main() function, and add socket codes such as creating, binding, listening, and accepting connections before this function and related to receiving data After the code, add the relevant codes for sending data and disconnecting and closing the socket, save and regenerate the C code for the flight control model, and then get the flight control program with the server code added, and realize the simulation platform communication. server. After starting the program, the program will be in the state of listening to the client, and the flight control program will continue to run until the client connection request arrives;

Then use the same method to establish the client, the difference is that after the client socket is established, it is not necessary to use the bind() function to bind the socket, but to use the connect() function to send the specified server socket Connection request.

After completing the construction of the communication network, still taking the longitudinal model as an example, build the aircraft model in simulink. The controller has seven inputs, which are velocity V, track angle γ, angle of attack α, throttle opening β, altitude h, pitch rate q and the first derivative of throttle opening There are two outputs, throttle opening command β _c and elevator deflection angle δ _e . In order to ensure that the data output by the aircraft model and the data received by the flight control program are at the same time and with the same accuracy, it is necessary to set the solver to a fixed step size, ode4 algorithm, and a fixed step size of 0.05 in the Configuration Parameters panel of the aircraft model. This is the same as the basic parameter setting of the flight control program.

In order to enhance its readability, the model is packaged as a subsystem, and the C-MEX Sfunction module is introduced to act as a client, and named client.c, to communicate with the server of the flight control program. In the final vehicle model, the input of the C-MEXSfunction module is the seven output variables of the vehicle model, and the output is the received two input variables of the vehicle model.

Then modify the C-MEX Sfunction module and write the client code:

The first step is to change the name of the Sfunction module to client, add the header file required by the client code, define the required variables, set an input port number in the mdlInitializeSizes() function of the Sfunction module, and the input dimension is 7; The number of output ports is 1, the output dimension is 2; the sampling time is 0.05; other settings keep the default values;

The second step is to declare and define the data type conversion sub-function outside the body of all functions, and create a client socket in the mdlStart() function, and set the server information to be connected, such as IP address and port number; in mdlOutputs () function to send and receive data;

The third step is to close the client socket in the mdlTerminate() function and release system resources;

Finally, enter the mex client.c command in the command window of MATLAB to compile the C-MEXS function just edited.

(3) Realization of real-time simulation

Since the simulation time of the simulation model is much faster than the system time, in order to make the MATLAB simulation time consistent with the real time, it is necessary to add delay codes in the client and server programs to make the aircraft model receive control commands at a certain time interval. Using the Clock module in the Simulink module library can easily get the time used by the current simulation, calculate the time difference that needs to be delayed, and use the Sleep function in C language to delay the time to achieve the effect of real-time simulation. After modifying the code, it is necessary to regenerate the C code and executable program for the flight control program, and the Sfunction module of the aircraft model needs to recompile the client.c file.

As shown in Figure 2, the simulation module should be able to realize five functions: real-time data reception, real-time data display, data storage, data viewing, and real-time curve drawing. The system block diagram is shown in Figure 1. The data receiving module receives the data from the client, and transmits the data to the real-time data display module, data storage module and real-time curve drawing module. The data storage module transfers the data to the data viewing module after processing. After all the background modules have processed the incoming data, they will be uniformly transmitted to the human-computer interaction interface, and the data will be displayed for platform users to view.

According to the functional requirements of the simulation module, its interface is planned as shown in Figure 2. The upper left corner is the picture of the aircraft, the upper right corner is the data storage and viewing part, and the lower part is the data analysis curve to display the real-time changes of various parameters. process.

The platform uses VC6.0 as a development tool and uses C++ for programming. The following will introduce its development process.

(1) Overall layout design

First open VC6.0, create a new MFC single-document exe program, save it and name it chap10, insert a new DIALOG, and insert a static text in the upper middle position, change its title to "distributed aircraft simulation platform simulation Management software", add three group boxes in DIALOG1 respectively, among which the upper right corner and the right lower group boxes are respectively named "data storage and viewing" and "data analysis". Add a picture control to the group box in the upper left corner and insert the picture of the aircraft. The data storage and analysis group box is added with a list control, and at the same time, a view data button is added to prepare for the implementation of the data view module later. Finally, taking the longitudinal model of the hypersonic vehicle as an example, add seven Teechart controls in sequence in the data analysis group box, adjust their sizes appropriately, and arrange them neatly.

(2) Real-time data reception

Use the server=socket function to set the port address of the management software socket on the server side, and set the socket attribute at the same time, and use server_addr.sin_port=htons(6000) to bind the socket, and the management software is the server socket The interface is set to monitor state, so that the management software is always in the state of waiting for connection.

When the management software, that is, the server, monitors or receives the connection request from the client, that is, the aircraft model, it responds to the request and creates a new thread at the same time. Send the server-side description to the client, and wait for the client to confirm the description. Once confirmed, the connection is established, and the server provides corresponding services to the client. The server is in the previous listening state again, and continues to wait for connection requests from other clients to complete. Communications and Services. Use the Getdata() function to receive data, that is, to provide corresponding services to the request.

(3) Data real-time display

For the real-time data display module, since new data arrives every 20ms, the data needs to be updated every 20ms. Insert a listbox control in the appropriate position of the interface, that is, the data storage and viewing group box, and associate this control with the variable m_list. During the initialization process of the control, use the m_list.InsertItem() function to correspond to each column in the first row of the list In the loop body, the seven data received in each cycle of the real-time data receiving module are composed of int type (serial number, not received by the previous module) and double type variables (data received) through the sprintf() function The data received by the module) is uniformly transformed into a char variable, and the seven data received this time are displayed in real time in the corresponding position of the corresponding table in the human-computer interaction interface by using the m_list. deal with). The display effect is shown in Figure 3.

(4) Data storage

After data is received, in addition to displaying it, it needs to be stored for viewing. First, use the gcvt function to convert the floating-point number into a string, and return a pointer to the storage location of the string, that is, the buffer. Assign a value to data[i], and represent the strings pointed to by the seven pointers in sequence. Then generate and open the named testdata.txt file, and use the fputs function to write a string to the file. After a string is successfully written, the position pointer of the file will automatically move backward, thus writing a set of data . Use the conditional statement to judge, and write a line break every seven data, and clear the buffer at the same time. Repeat this process until the aircraft simulation system stops running.

(5) View and save data

On the basis of data storage, the functions of data viewing and saving are realized. First add a "View Data" button on the main interface, and use this button to execute the function of running and controlling a specified external program through the ShellExecute() function. In the design of this external program, first add an edit box at an appropriate position, and associate the variable m_FileText, and add two buttons on the interface, namely "Open" and "Save As", to realize opening the text document and saving the document as to other path functions.

The "Open" button click event opens the text document to be displayed, reads the content in the document in turn, closes the selected document, and displays the content in the document in the edit box; the "Save As" button clicks the event processing function Display the save as document path, and create a text document, obtain the content displayed in the edit box before, write the data in the edit box in the saved text document, and close the save as text through file.Close() document. The effect diagram is shown in Figure 4.

(6) Real-time curve drawing

After each set of data is received, the seven received data are corresponding to the time nodes one by one, and are added to the corresponding seven real-time graphs in the form of coordinate points, thereby forming seven curves.

Download and register the control Teechart, add 7 Teechart controls in sequence in the appropriate different positions of the interactive interface, that is, the data analysis group box, and initialize them respectively, such as naming, selecting the chart type, setting the horizontal and vertical coordinates, etc., and linking the seven controls to m_chart respectively , m_chart1, m_chart2, m_chart3, m_chart4, m_chart5, m_chart6 seven variables. After receiving seven real-time data each time, use the m_chart.Series(0).Add() function to draw each data in the graph, and loop the drawing process until the end of the simulation. Its final interface is shown in Figure 5.

3. Vision module

The main function of the visual module in the simulation platform is to display the flight status of the aircraft in the form of animation in real time. For this reason, the visual module needs to have the function of data reception, and at the same time, it must ensure the real-time performance of animation transformation. Its structural block diagram is shown in Figure 6. This patent uses OpenGL to complete the basic scene drawing, based on VC++, builds the software framework through the exe program of MFC, achieves the effect of aircraft movement through coordinate transformation, realizes the animation effect through the double buffer function, and realizes the real-time simulation function through the data transmission module.

(1) Basic scene drawing

First complete the establishment of aircraft model and scene model. The aircraft model is drawn and rendered by linking the OpenGL graphics library, and its simple model is shown in Figure 7. In order to make the simulation have a more realistic visual effect, functions such as glFrustum() and gluLookAt() are used to build the simulation space, and the background of the starry sky is made by combining random refresh points and regular movement of fixed points, and an earth model is added.

(2) Software framework construction

Next, the OpenGL function is implemented in the MFC single-document environment, and the environment of the entire simulation software is built. Start VC++6.0 to create a new MFC single-document exe program, change the header file, add #include gl\gl.h and #include gl\glu.h before the program, open the link button, in front of various linked libraries Add OpenGL32.Lib and glu32.Lib, and add mydraw(), mypixelformat(), myfirst() functions, set the pixel format in the function mypixelformat(), create a rendering description table in the myfirst() function, and use the Onsize() function Set the field of view and viewpoint in OnDraw(), add background processing in OnDraw(), add drawing statements in mydraw(), edit various icons and button operations in Dialog, and complete the creation of the field of view.

After the field of view is created, import the drawn aircraft model and simulated space model, including the starry sky and the earth. Start the timer function by button operation, create a query network connection code in the timer function, use the socket to realize the establishment of the network channel, and receive and use the data.

As shown in Figure 10, for the convenience of observation, create a new button in the toolbar, create the corresponding command of the button, add the class of the response function, and write the full-screen display code in the corresponding function obtained. Create two mouse response functions at the beginning, and write in the response codes, which correspond to mouse button press and mouse button lift, respectively, to open the OpenGL program. Since the color of the graphic has not been defined by fixed points, a display is displayed at this time. Basic software framework on a black screen.

OpenGL uses the glColor() function to define the color, and calls glColor3f(x, y, z) to define the color value used in the next drawing. The three values of the function are the display matrix of the three primary colors. But sometimes the displayed color does not naturally represent the real color of the object, so OpenGL introduces the concept of lighting and object material while defining the vertex color of the object.

OpenGL starts the lighting application through the function glEnable(GL_LIGHTING), turns off the lighting through the function glDisable(GL_LIGHTING), and defines the lighting properties through the function glLightfv(GLenum light, GLenum pname, constGLfloat*p). Here, the general global diffuse lighting is used; OpenGL The material variable is set through the function glMaterialfv(GLenum face,GLenum pname,const GLfloat*p), and the most basic metal-like material setting is used here.

Furthermore, in order to make the image look softer, anti-aliasing processing is performed. OpenGL uses glEnable (GL_POINT_SMOOTH) to enable point anti-aliasing, and glDisable (GL_POINT_SMOOTH) to block anti-aliasing. Lines and polygons correspond to LINE and POLYGON.

Finally, set the planet map. OpenGL completes the drawing by directly operating on the pixels and completing the bitmap operation of the image. The details are as follows: OpenGL uses the glReadPixels() function to read and save an image in the color buffer, draws the image of the array to the position of the screen raster through the glDrawPixels() function, and the function glCopyPixels() completes copying the image from the screen to the position of the raster screen position.

(3) Real-time animation and simulation

After completing the construction of the simulation environment, the animation and real-time simulation will be implemented below. OpenGL uses double-buffer computer graphics technology to realize animation, and the model change is realized through coordinate transformation. The process is shown in Figure 8.

When using coordinate transformation to draw an image, you can call the glTranslate(x,y,z) function to define the displacement of the position of the model displayed on the screen; call the glRotate(angle,x,y,z) function to represent the rotation around x and y respectively , the z-axis rotates the angle to realize the control of the aircraft angle; by calling the glScalef (a,b,c) function to indicate the change of the far and near large; by calling the glMatrixMode(GL_PROJECTION) function to start the projection matrix, perform projection transformation, and convert the The coordinates are converted into two-dimensional screen coordinates, and the three-dimensional virtual objects are displayed on the computer screen, so that users have the concept of viewing distance and field of view, and the viewing experience is more realistic; by calling the function glViewport(0,0,cx,cy) to Define the scope of the viewport, which can produce the effect of split screen, that is, display multiple viewports under the same window.

In order to realize the animation effect, add the switch variable flykey to the public variable, add the button function to respond to myflykey() in the public function, add the code SetTimer(1, 50, NULL) to start the system timer in the myflykey() function, press After pressing the open button to enter the flight state, the timer is continuously refreshed, and then the image refreshed each time is drawn, and the double buffering technology is used to call the SwapBuffers() function after the calculation of the screen update drawing is completed, and the screen and the background cache image are completed. is displayed alternately, resulting in an animation effect.

For the real-time receiving and processing of data, firstly refer to the previous article to establish communication with the simulation module, add the code for receiving data in the timer function of the main program, and borrow the loop of the main program to receive the flight attitude data in real time and draw it.

The simulation platform is based on the Windows operating system. MATLAB is used to build the aircraft model and controller, and the simulation is carried out. C++ is used to develop the simulation module based on VC6.0, and VC++ is used to develop the visual module based on OpenGL, and the joint simulation is carried out.

The three modules are connected to the same switch using three Ethernet cables, and the IP addresses of the local connections are respectively set in the network neighbors so that the IP addresses of the three modules are in the same network segment. To test whether the three modules can communicate, after entering "ping target IP address" in the windows command prompt, the modules will automatically perform a communication test.

After the test is correct, the distributed aircraft simulation platform can be started. In the client/server mode, the server program must be started prior to the client program, otherwise the communication will not be successful. So start the simulation module and the vision module first.

Then enter the following commands in the MATLAB command window of the main control module:

! flight_ctrl -tf inf -w &

The function of this command is to open the flight control external program in an infinite running state, and the start and stop of the program are controlled by Simulink. Then click the Connect and Run button in the Simulink model of the flight control program. After all the server programs are started, the corresponding programs will be blocked until the aircraft model transmits data through the client, and each program will continue to run.

After all the server programs are started, in the aircraft model, click the run button in the normal simulation mode, and the distributed aircraft simulation platform starts to run. During the operation of the simulation platform, the simulation can be suspended and continued at any time through the pause button in the main control module, and the stop button can terminate the simulation. Users can directly modify the command parameters in the Simulink model of the flight control program, and realize the function of real-time online adjustment of the aircraft state through the external mode.

The off-line simulation of the aircraft model and controller is carried out first, and the configuration is consistent with the simulation platform. , and compare it with the results of the simulation platform as a standard to verify its feasibility.

It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (3)

1. A small-scale distributed hypersonic vehicle real-time simulation system is composed of a main control module, a simulation module and a visual module, and is characterized in that, The main control module is the hub of the entire distributed simulation platform. It simulates the aircraft model in the Simulink environment, transmits data with the simulation module during the simulation process, and transmits the attitude data to the visual module. It also has the functions of controlling the simulation start-stop and storage Functions for simulating data; The simulation module is equivalent to the controller of the aircraft. It runs the flight control program and server program that support the Simulink external mode. According to the aircraft attitude data and given parameters transmitted from the main control module, control instructions are given through calculation and sent to the main control module; Wherein, the simulation module includes a data receiving module, a real-time data display module, a data storage module, a data viewing module, a real-time curve drawing module and a human-computer interaction interface; The visual module runs the visual software, is responsible for receiving the attitude data of the aircraft transmitted by the main control module in real time, and displays the real-time state of the aircraft in the form of animation, so that the user can observe the whole simulation process more intuitively, wherein: the visual module includes animation display Unit, visual display unit, data receiving and processing unit, aircraft model and scene model. 2. a kind of small-scale distributed hypersonic vehicle real-time simulation system according to claim 1, it is characterized in that: comprise the steps: S1, the simulation module sets initial parameters; S2, the main control module starts the simulation process; 2.1. RTW-based flight control program conversion; 2.2. Build a conversion communication network; 2.3. Real-time simulation processing; S3, the simulation module receives the corresponding data and distributes different data processing modules to realize the human-computer interaction to the aircraft output data output and curve image process; S4, the visual module receives corresponding data and displays the flight state of the aircraft in the form of animation; S5, the simulation module realizes online parameter adjustment through the man-machine exchange interface, if the curve image in the simulation module and the state of the aircraft in the visual module meet the requirements, then end the simulation state; otherwise, return to step S2. 3. a kind of small-scale distributed hypersonic vehicle real-time simulation system according to claim 2, it is characterized in that: described main control module and simulation module carry out data transmission based on TCP/IP communication protocol, main control module and simulation module adopt Client/server mode, the client sends the attitude data of the aircraft model to the server, the server receives the attitude data and sends the control commands output by the flight control program to the aircraft model, and the client and server are programmed using the SOCKET socket of C language Code to realize the normal sending and receiving function of data.