Multi-domain simulation system and construction method of three-axis turntable based on modelica

Abstract

The application relates to a Modelica-based multi-field simulation system of a three-axis turntable and a construction method, and belongs to the technical field of modeling simulation, and solves the problems of compatibility, precision and solving efficiency of modeling simulation of a three-axis turntable in the prior art, including: a modeling field of the three-axis turntable constructed based on Modelica, including a mechanical field, an electrical field and a control field; the mechanical field includes a three-axis turntable mechanical model, a reducer model for providing a reduced rotation angle signal and an amplified torque signal, and a shaft coupling model; the electrical field includes a motor model for providing a torque signal, a driving circuit model for providing a power voltage source, and a conversion circuit model for providing a converted voltage signal to the motor model; the control field includes a control instruction model for providing a theoretical rotation angle signal instruction, a PID controller model for calculating and providing a control instruction required by the conversion circuit model, and a sensor model for collecting and feeding back a signal required by the PID controller model.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of modeling simulation, in particular to a three-axis turntable multi-field simulation system based on Modelica and a construction method. BACKGROUND

[0002] Three-axis turntables are widely used in high-precision fields such as military and aerospace, and their performance indicators are crucial. Small errors in the turntable can affect its performance, so accurate multi-field modeling is needed. Through multi-field modeling, mechanical, electrical, control and other factors can be integrated to comprehensively and deeply analyze the operating characteristics of the turntable under different working conditions, accurately predict possible errors and optimize them in advance. This helps to improve the precision, stability and reliability of three-axis turntables and ensures the accurate operation of related equipment in military and aerospace tasks.

[0003] Three-axis turntables span multiple disciplines in design and analysis, including mechanical systems, control systems, and electrical systems. There is a close correlation and high coupling between the systems, which makes the modeling process extremely complex. The current mainstream modeling method implementation path is as follows: first, use the corresponding software to model and simulate each subsystem of the three-axis turntable separately to achieve single modeling in the corresponding field of each subsystem; then, on the basis of the first step, use a communication interface for multi-software joint simulation. However, the complex configuration of the communication interface and the weak compatibility of the solvers of each software significantly increase the technical difficulty of the multi-software joint simulation step. Even if a lot of time is invested in building a multi-software joint simulation environment, due to the relatively independent architecture of each software, the coupling characteristics between multiple systems are easily decoupled during data exchange, which reduces the solution accuracy and efficiency. In addition, the model built using multi-software joint simulation has poor reusability and reconfigurability, and needs to be adjusted in structure and modified in code when applied to multiple different scenarios, which is low in development efficiency.

[0004] Therefore, there is a need in the art for improved three-axis turntable simulation systems and methods that provide high compatibility, high precision, and high solution efficiency. SUMMARY

[0005] In view of the above problems, the present application provides a three-axis turntable multi-field simulation system based on Modelica and a construction method, which solves the problem of weak compatibility, poor reusability and reconfigurability, and low development efficiency of the model built in the prior art.

[0006] According to one embodiment of the present application, a three-axis turntable multi-field simulation system based on Modelica is provided, comprising:

[0007] The modeling field of the three-axis turntable constructed based on Modelica includes a mechanical field, an electrical field, and a control field;

[0008] The mechanical field includes a three-axis turntable mechanical model which is an actual moving part of the three-axis turntable, a reducer model which provides a reduced rotation speed signal and an amplified torque signal, and a coupling model;

[0009] The electrical field includes a motor model which provides a torque signal required by the three-axis turntable, a driving circuit model which provides a power voltage source, and a conversion circuit model which provides a converted voltage signal to the motor model;

[0010] The control field includes a control instruction model which provides a theoretical rotation angle signal instruction, a PID controller model which calculates and provides a control instruction required by the conversion circuit model, and a sensor model which collects and feeds back a signal required by the PID controller model.

[0011] Optionally, the three-axis turntable mechanical model is configured to receive the reduced torque signal and the rotation speed signal from the reducer model, generate actual rotation angle signals and rotation speed signals of the three-axis turntable, and output to the sensor model;

[0012] The reducer model is configured to receive the torque signal and the rotation speed signal from the motor model, generate the reduced torque signal and the rotation speed signal, and output to the three-axis turntable mechanical model;

[0013] The motor model is configured to receive the converted voltage signal and the current signal from the conversion circuit model, generate the torque signal, the rotation speed signal, and the current signal, output the torque signal and the rotation speed signal to the reducer model, and output the current signal to the sensor model;

[0014] The driving circuit model is configured to generate the voltage signal and the current signal, and output to the conversion circuit model;

[0015] The conversion circuit model is configured to receive the voltage signal and the current signal from the driving circuit model, and receive the control signal from the PID controller model, generate the converted voltage signal and the current signal, and output to the motor model;

[0016] The control instruction model is configured to generate the theoretical rotation angle signal of the three-axis turntable, and output to the PID controller model;

[0017] The PID controller model is configured to receive the theoretical rotation angle signal of the three-axis turntable from the control instruction model, and receive the current signal, the rotation angle signal, and the rotation speed signal from the sensor model, generate the control signal, and output to the conversion circuit model;

[0018] The sensor model is configured to receive the current signal from the motor model, and receive the actual rotation angle signal and the rotation speed signal of the three-axis turntable mechanical model, generate the current signal, the rotation angle signal and the rotation speed signal, and output to the PID controller model.

[0019] The second embodiment of the application provides a construction method of a Modelica-based three-axis turntable multi-domain simulation system, comprising the following steps:

[0020] Step 1, modeling the three-axis turntable based on Modelica, determining the modeling domain and unit component of the three-axis turntable;

[0021] Step 2, constructing the unit component model of each modeling domain of the three-axis turntable, determining the data signal transmission mode in the component to define the interface;

[0022] Step 3, constructing the mechanical model, the electrical model and the control system of the three-axis turntable according to the unit component model, completing the connection of the signal flow between each unit component model and the module of each modeling domain, and obtaining the Modelica-based three-axis turntable multi-domain simulation system;

[0023] Step 4, performing interface matching and parameter adjustment, setting different motion process parameters for the Modelica-based three-axis turntable multi-domain simulation system, and performing simulation test;

[0024] In the step 1, the following steps are included:

[0025] Step 1.1, modeling the three-axis turntable based on Modelica, setting the modeling domain of the three-axis turntable to include the mechanical domain, the electrical domain and the control domain;

[0026] Step 1.2, setting the mechanical domain of the three-axis turntable to include the mechanical model of the three-axis turntable, the reducer model and the coupling model;

[0027] Step 1.3, setting the electrical domain of the three-axis turntable to include the motor model, the driving circuit model and the conversion circuit model;

[0028] Step 1.4, setting the control domain of the three-axis turntable to include the control instruction model, the PID controller model and the sensor model.

[0029] Optionally, the step 2 includes the following steps:

[0030] Step 2.1, a three-axis turntable mechanical model in the mechanical field is constructed, and the three-axis turntable mechanical model is associated with a standard three-dimensional geometric file, so that the three-axis turntable mechanical model obtains the properties of the geometric model, the three-axis turntable mechanical model receives the reduced torque signal and the reduced speed signal from the reducer model, generates the actual rotation angle signal and the rotation speed signal of the three-axis turntable, and outputs to the sensor model;

[0031] Step 2.2, a reducer model of the three-axis turntable in the mechanical field is constructed, the reducer model receives the torque signal and the speed signal output by the motor model, and converts the torque signal and the speed signal, and outputs the converted torque signal and the speed signal to the three-axis turntable mechanical model;

[0032] Step 2.3, a motor model of the three-axis turntable in the electrical field is constructed, the motor model receives the converted voltage signal and the current signal from the conversion circuit model, generates the torque signal and the speed signal and outputs to the reducer model, and generates the current signal and provides to the sensor model;

[0033] Step 2.4, a driving circuit model of the three-axis turntable in the electrical field is constructed, the driving circuit model provides the voltage signal and the current signal for the conversion circuit model;

[0034] Step 2.5, a conversion circuit model of the three-axis turntable in the electrical field is constructed, the conversion circuit model generates the converted voltage signal and the current signal according to the control signal provided by the PID controller model and the voltage signal and the current signal provided by the driving circuit model, and outputs the converted voltage signal and the current signal to the motor model, to control the output torque signal and the speed signal of the motor model;

[0035] Step 2.6, a control instruction model of the three-axis turntable in the control field is constructed, the control instruction model generates the theoretical rotation angle signal of the three-axis turntable mechanical model, and outputs to the PID controller model;

[0036] Step 2.7, a sensor model of the three-axis turntable in the control field is constructed, the sensor model receives the current signal from the motor model and the actual rotation angle signal and the rotation speed signal of the three-axis turntable from the three-axis turntable mechanical model, generates the current signal, the rotation angle signal and the rotation speed signal, and outputs to the PID controller model;

[0037] Step 2.8, a PID controller model of the three-axis turntable in the control field is determined, the PID controller model obtains the control signal through the control algorithm according to the theoretical rotation angle signal of the three-axis turntable mechanical model received from the control instruction model, and the current signal, the rotation speed signal and the rotation angle signal received from the sensor model, and outputs to the conversion circuit model.

[0038] Optionally, step 2.2 specifically includes the following steps:

[0039] Step 2.2.1, the equation for constructing the reducer model is:

[0040] T m = T J-in + J J-in a J-in + T f-in

[0041] iT f-in = T J-out + J J-out a J-out + T f-out

[0042] T f-in = T c-in sign(w J-in ) + B J-in w J-in

[0043] T f-out = T c-out sign(w J-out ) + B J-out w J-out

[0044] w J-in = iw J-out

[0045] wherein i is the reducer transmission ratio, T m is the motor input torque, T J-in is the reducer input torque, T J-out is the reducer output torque, T f-in is the reducer input end friction torque, T f-out is the reducer output end friction torque, w J-in is the reducer input end speed, w J-out is the reducer output end speed, a J-in is the reducer input end angular acceleration, a J-out is the reducer output end angular acceleration, J J-in is the reducer input end moment of inertia, J J-out is the reducer output end moment of inertia, T c-in is the reducer input end static friction torque, T c-out is the reducer output end static friction torque, B J-in is the reducer input end damping coefficient, B J-out is the reducer output end damping coefficient;

[0046] Step 2.2.2, determine the type of reducer model, if it is a worm and worm reducer model or a spur gear reducer model, execute step 2.2.3, otherwise it is a direct drive model, execute step 2.3;

[0047] In step 2.2.3, determine whether the reducer model is a worm gear model or a spur gear model, introduce a coupling model, and convert the torque signal and speed signal received from the motor model into the coupling model. The converted torque signal and speed signal are then output to the reducer model. The coupling model is constructed as follows:

[0048] T L-out =K L (θ L-in -θ L-out )

[0049] T m -T L-out =J L α L-out +B L w L-out

[0050] Among them, T L-out is the coupling output torque, θ L-in is the coupling input angle, θ L-out is the coupling output angle, K L is the torsional stiffness of the coupling, w L-out is the coupling output speed, α L-out is the coupling output angular acceleration, J L is the moment of inertia of the coupling output end, B L is the damping coefficient of the coupling output end.

[0051] Optionally, step 2.3 specifically includes the following steps:

[0052] Step 2.3.1, determine the type of motor model. If it is a permanent magnet DC motor, proceed to step 2.3.2; otherwise, if it is a brushless DC motor, proceed to step 2.3.3.

[0053] Step 2.3.2, the equation for constructing the permanent magnet DC motor model is:

[0054]

[0055] T m =C e I

[0056] e=K m w m

[0057]

[0058] Where U is the motor applied voltage, I is the motor current, R is the motor armature resistance, L is the motor armature inductance, e is the armature back electromotive force, T eis the motor shaft output torque, T L is the motor shaft load torque, J m is the motor shaft moment of inertia, B m is the motor damping coefficient, w m is the motor rotation angle, K m is the motor back electromotive force constant, C e is the motor torque constant; then proceed to step 2.4;

[0059] Step 2.3.3, the equation for constructing the brushless DC motor model is:

[0060]

[0061]

[0062] P e =e A i A +e B i B +e C i C

[0063]

[0064] Among them, U A 、U B 、U C are the terminal voltages of the three-phase windings, i A 、i B 、i C They are the terminal currents of the three-phase windings, R A 、R B 、R C are the resistance of the three-phase windings, L A , L B , L C are the inductance of the three-phase winding, e A 、e B 、e C They are the back electromotive force of the three-phase winding, T e is the motor shaft output torque, T L is the motor shaft load torque, J m is the motor shaft moment of inertia, B m is the motor damping coefficient, w m is the motor rotation angle, P e is the motor power.

[0065] Optionally, step 2.5 specifically includes the following steps:

[0066] Step 2.5.1, determine the type of motor model, if it is a permanent magnet DC motor model, execute step 2.5.2, otherwise it is a brushless DC motor model, execute step 2.5.3;

[0067] Step 2.5.2, the motor model is a permanent magnet DC motor model, the circuit model is converted using a DC-DC transformer model, and the voltage signal required by the motor model is provided, and then step 2.6 is executed;

[0068] Step 2.5.3, the motor model is a brushless DC motor model, the circuit model is converted using a three-phase full-bridge inverter model, and the DC voltage signal received from the drive circuit model is converted into the voltage signal required by the motor model, the three-phase full-bridge inverter includes six bridge arms: first bridge arm AR, second bridge arm AL, third bridge arm BR, fourth bridge arm BL, fifth bridge arm CR and sixth bridge arm CL.

[0069] Optionally, the theoretical rotation angle signal of the three-axis turntable mechanical model in step 2.6 includes the theoretical rotation angle signals of the base model, the azimuth axis model, the pitch axis model and the roll axis model respectively.

[0070] Optionally, the sensor model of the three-axis turntable in the control field constructed in step 2.7 includes current sensors, speed sensors, rotation angle sensors and Hall sensors.

[0071] Optionally, step 2.8 includes constructing the control equation of the PID controller model of the three-axis turntable in the control field:

[0072]

[0073] Wherein, error(t) is the control deviation, t is the time, f(error) is the control signal calculated after the control algorithm, k P is the proportional control coefficient, k I is the integral control coefficient, k D is the differential control coefficient.

[0074] Compared with the prior art, the three-axis turntable multi-field simulation system and construction method based on Modelica provided by the application at least have the following beneficial effects:

[0075] (1) Multi-field collaborative simulation: through Modelica modeling, a unified language is used to describe the knowledge of multiple disciplines in the same platform and framework, unified modeling and simulation analysis are performed, and the modeling efficiency and accuracy of the three-axis turntable can be effectively improved.

[0076] (2) universality: using the modularization characteristics of Modelica, a modular simulation system is quickly formed, different reducer models, motor models and control modes can be selected according to different requirements, a large amount of code writing work is saved, and the reusability and reconfigurability of the simulation system are enhanced.

[0077] (3) the multi-system modeling method based on the Modelica language is adopted, the simulation results can be visually analyzed, and the motion analysis is carried out in combination with three-dimensional animation and curves, so that the debugging efficiency and modeling accuracy of the model are improved. BRIEF DESCRIPTION OF DRAWINGS

[0078] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below, and the features and advantages of the present application can be more clearly understood by referring to the drawings. The drawings are schematic and should not be understood as any limitation on the present application. For those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0079] Figure 1 is a flow chart of a construction method of a Modelica-based three-axis turntable multi-field simulation system according to an embodiment of the present application.

[0080] Figure 2 is a schematic diagram of a Modelica-based three-axis turntable multi-field simulation system according to an embodiment of the present application.

[0081] Figure 3 is a schematic diagram of the connection between the signal flows of the modules of a Modelica-based three-axis turntable multi-field simulation system according to an embodiment of the present application.

[0082] Figure 4 is a three-phase inverter structure schematic diagram in a three-axis state conversion circuit model of a Modelica-based three-axis turntable multi-field simulation system according to an embodiment of the present application.

[0083] Figure 5 is a theoretical rotation angle signal and an actual rotation angle signal of an azimuth axis of a three-axis turntable in an example of a Modelica-based three-axis turntable multi-field simulation system according to an embodiment of the present application.

[0084] Figure 6 is a theoretical rotation angle signal and an actual rotation angle signal of an elevation axis of a three-axis turntable in an example of a Modelica-based three-axis turntable multi-field simulation system according to an embodiment of the present application.

[0085] Figure 7is a theoretical rotation angle signal and an actual rotation angle signal of an output shaft of a three-axis turntable in one example of a Modelica-based three-axis turntable multi-field simulation system provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0086] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0087] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0088] The Modelica-based three-axis turntable multi-field simulation system and construction method according to an embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0089] As shown in Figure 2 and Figure 3 , the Modelica-based three-axis turntable multi-field simulation system according to an embodiment of the present application includes a modeling field of a three-axis turntable constructed based on Modelica, including a mechanical field, an electrical field and a control field; the mechanical field includes a three-axis turntable mechanical model as an actual moving component of the three-axis turntable, a reducer model providing a rotation angle signal after reduction and an amplified torque signal, and a coupling model; the electrical field includes a motor model providing a torque signal required by the three-axis turntable, a driving circuit model providing a power voltage source, and a conversion circuit model providing a converted voltage signal to the motor model; the control field includes a control instruction model providing a theoretical rotation angle signal instruction, a PID controller model calculating and providing a control instruction required by the conversion circuit model, and a sensor model collecting and feeding back a signal required by the PID controller model.

[0090] In this embodiment, the three-axis turntable mechanical model can be configured to receive the reduced torque signal and the rotation angle signal from the reducer model, generate the actual rotation angle signal and the rotation speed signal of the three-axis turntable, and output to the sensor model. The reducer model can be configured to receive the torque signal and the rotation angle signal from the motor model, generate the reduced rotation angle signal and the rotation speed signal, and output to the three-axis turntable mechanical model. The motor model can be configured to receive the voltage signal and the current signal from the conversion circuit model, generate the rotation angle signal, the rotation speed signal and the current signal, output the rotation angle signal and the rotation speed signal to the reducer model, and output the current signal to the sensor model. The drive circuit model can be configured to generate the voltage signal and the current signal, and output to the conversion circuit model. The conversion circuit model can be configured to receive the voltage signal and the current signal from the drive circuit model, and receive the control signal from the PID controller model, generate the voltage signal and the current signal and output to the motor model. The control instruction model can be configured to generate the theoretical rotation angle signal of the three-axis turntable, and output to the PID controller model. The PID controller model can be configured to receive the theoretical rotation angle signal of the three-axis turntable from the control instruction model, and receive the current signal, the rotation speed signal and the rotation angle signal from the sensor model, generate the control signal and output to the conversion circuit model. The sensor model can be configured to receive the current signal from the motor model, and receive the actual rotation angle signal and the rotation speed signal of the three-axis turntable from the three-axis turntable mechanical model, generate the current signal, the rotation angle signal and the torque signal, and output to the PID controller model.

[0091] As shown in Figures 1 to 3 , the construction method of the Modelica-based three-axis turntable multi-domain simulation system according to another embodiment of the present application comprises the following steps. Modeling based on Modelica, first, according to the field, the three-axis turntable model is divided into mechanical, electrical and control fields, and the unit components existing in each field are determined; constructing unit components of each modeling field of the three-axis turntable, determining data signals in the components to define the interface; according to the unit components, the mechanical model, the electrical model and the control system of the three-axis turntable are built, the connection between each unit component and each field module is completed, and the three-axis turntable multi-domain simulation system is obtained.

[0092] Step 1, modeling the three-axis turntable based on Modelica, determining the modeling field of the three-axis turntable. This step 1 specifically includes the following steps.

[0093] Step 1.1, as shown in Figure 2 , modeling the three-axis turntable based on Modelica, setting the modeling field of the three-axis turntable can include mechanical field, electrical field and control field. It should be understood that, according to the need, the modeling field of the three-axis turntable can also include other fields.

[0094] Step 1.2, setting the three-axis turntable in the mechanical field can include: three-axis turntable mechanical model, reducer model and coupling model. Further, the reducer model can be further decomposed according to user selection, including but not limited to: direct drive model, worm and worm gear model and spur gear model.

[0095] Step 1.3, setting the three-axis turntable in the electrical field can include: motor model, drive circuit model and conversion circuit model. Further, the motor model can be further decomposed according to user selection, including: permanent magnet DC motor and brushless DC motor. The conversion circuit model is further decomposed according to the motor model selection, including: DC-DC transformer and three-phase inverter.

[0096] Step 1.4, setting the three-axis turntable in the control field can include: control instruction model, PID controller model and sensor model. Further, the PID controller model can be further decomposed according to user selection, including: PID controller and PI controller. The sensor model can be further decomposed into current sensor, speed sensor, angle sensor and Hall sensor according to user selection.

[0097] Step 2, constructing the unit component model of each modeling field of the three-axis turntable, determining the data signal transmission mode within the component and defining the interface. Optionally, the functions of each module are shown in Table 1 below, and the interfaces of each unit component model constructed are set according to the determined data signal transmission mode within the component.

[0098] Table 1

[0099]

[0100]

[0101] The step 2 specifically includes the following steps.

[0102] Step 2.1, constructing the three-axis turntable mechanical model of the three-axis turntable in the mechanical field, and associating the three-axis turntable mechanical model with the standard three-dimensional geometric file, so that the three-axis turntable mechanical model obtains the properties of the geometric model. The three-axis turntable mechanical model is the actual moving part of the three-axis turntable, which can be divided into base model, azimuth axis model, pitch axis model and roll axis model according to the structure and relative motion relationship. The three-axis turntable mechanical model receives the reduced torque signal and speed signal from the reducer model, generates the actual angle signal and speed signal of the three-axis turntable and outputs to the sensor model.

[0103] Step 2.2, constructing a reducer model of the three-axis turntable in the mechanical field. The reducer model receives the torque signal and the rotation speed signal output by the motor model, and converts the torque signal and the rotation speed signal, and outputs the converted torque signal and the rotation speed signal to the three-axis turntable mechanical model. In this embodiment, the reducer model can be set to a direct drive type reducer model, a worm and worm gear type reducer model, or a straight gear type reducer model according to user selection. The direct drive type reducer model directly outputs the torque signal output by the motor model to the three-axis turntable mechanical model; the worm and worm gear type reducer model or the straight gear type reducer model outputs the torque signal output by the motor model through gear transmission to the three-axis turntable mechanical model. Step 2.2 specifically includes the following steps.

[0104] Step 2.2.1, the equation of the reducer model is constructed as follows:

[0105] T m = T J-in + J J-in a J-in + T f-in

[0106] iT f-in = T J-out + J J-out a J-out + T f-out

[0107] T f-in = T c-in sign(w J-in ) + B J-in w J-in

[0108] T f-out = T c-out sign(w J-out ) + B J-out w J-out

[0109] w J-in = iw J-out

[0110] wherein i is a reducer transmission ratio, T m is a motor input torque, T J-in is a reducer input torque, T J-out is a reducer output torque, T f-in is a reducer input end friction torque, T f-out is a reducer output end friction torque, w J-in is a reducer input end rotation speed, w J-out is a reducer output end rotation speed, a J-in is a reducer input end angular acceleration, a J-outJ J-in is the moment of inertia of the reducer input end, J-out is the moment of inertia of the reducer output end, c-in is the static friction torque of the reducer input end, c-out is the static friction torque of the reducer output end, J-in is the damping coefficient of the reducer input end, J-out is the damping coefficient of the reducer output end, and sign(·) is the sign function.

[0111] Step 2.2.2, determine the type of reducer model, if it is a worm and worm gear type reducer model or a spur gear type reducer model, execute step 2.2.3, otherwise it is a direct drive type model, execute step 2.3.

[0112] Step 2.2.3, determine the type of reducer model as a worm and worm gear type model or a spur gear type model, need to introduce a coupling model, which converts the torque signal and speed signal received from the motor model and outputs the converted torque signal and speed signal to the reducer model. Considering the elastic state of the coupling, the coupling model is constructed as:

[0113] T L-out = K L (θ L-in - θ L-out )

[0114] T m - T L-out = J L α L-out + B L w L-out

[0115] where T m is the motor input torque, T L-out is the coupling output torque, θ L-in is the coupling input angle, θ L-out is the coupling output angle, K L is the coupling torsional stiffness, w L-out is the coupling output speed, α L-out is the coupling output angular acceleration, J L is the moment of inertia of the coupling output end, and B L is the damping coefficient of the coupling output end.

[0116] Step 2.3. Constructing a motor model of the three-axis turntable in the electrical field, the motor model receives the converted voltage signal and current signal from the conversion circuit model, generates and outputs the torque signal and rotation speed signal to the reducer model, and generates the current signal and provides it to the sensor model. The motor model can be divided into permanent magnet DC motor, brushless DC motor and separately excited DC motor according to user selection. Step 2.3 specifically includes the following steps.

[0117] Step 2.3.1, determine the type of motor model, if it is a permanent magnet DC motor, execute step 2.3.2, otherwise it is a brushless DC motor, execute step 2.3.3.

[0118] Step 2.3.2, the equation of the permanent magnet DC motor model is constructed as:

[0119]

[0120] T m =C e I

[0121] e=K m w m

[0122]

[0123] Where, U is the voltage applied to the motor, I is the motor current, R is the motor armature resistance, L is the motor armature inductance, e is the armature back electromotive force, T e is the motor shaft output torque, T L is the motor shaft load torque, J m is the motor shaft moment of inertia, B m is the motor damping coefficient, w m is the motor rotation angle, K m is the motor back-EMF constant, C e is the motor torque constant;

[0124] Next, step 2.4 is executed.

[0125] Step 2.3.3, the equation of the brushless DC motor model is constructed as:

[0126]

[0127] P e =e A i A +e B i B +e C i C

[0128]

[0129] wherein, U A , U B , U C are the end voltages of the three-phase winding, i A , i B , i C are the end currents of the three-phase winding, R A , R B , R C are the resistances of the three-phase winding, L A , L B , L C are the inductances of the three-phase winding, e A , e B , e C are the counter electromotive forces of the three-phase winding, T e is the output torque of the motor shaft, T L is the load torque of the motor shaft, J m is the moment of inertia of the motor shaft, B m is the damping coefficient of the motor, w m is the rotation angle of the motor, P e is the power of the motor.

[0130] Step 2.4, constructing a drive circuit model of the three-axis turntable in the electrical field, which includes voltage sources, current sources, resistors, inductors and other electrical elements inside the drive circuit model, providing voltage signals and current signals for the conversion circuit model.

[0131] Step 2.5, constructing a conversion circuit model of the three-axis turntable in the electrical field. The conversion circuit model generates processed appropriate voltage signals and current signals according to the control signals provided by the PID controller model and the voltage signals and current signals provided by the drive circuit model, and outputs them to the motor model to control the output torque signal and the rotation speed signal of the motor model. This step 2.5 specifically includes the following steps.

[0132] Step 2.5.1, determining the type of motor model, if it is a permanent magnet DC motor model, executing step 2.5.2, otherwise it is a brushless DC motor model, executing step 2.5.3.

[0133] Step 2.5.2, the motor model is a permanent magnet DC motor model, the conversion circuit model uses a DC-DC transformer model to provide the voltage signals required by the motor model; then executing step 2.6.

[0134] Step 2.5.3, as shown in Figure 4 , the motor model is a brushless DC motor model, the conversion circuit model uses a three-phase full-bridge inverter model to convert the DC voltage signals received from the drive circuit model into voltage signals required by the motor model. Referring to Figure 4The three-phase full-bridge inverter includes six bridge arms: a first bridge arm AR, a second bridge arm AL, a third bridge arm BR, a fourth bridge arm BL, a fifth bridge arm CR, and a sixth bridge arm CL.

[0135] Table 2 below shows the correspondence between the conduction state of each phase of the three-phase full-bridge inverter and the rotor phase, where the state is 1 when the phase bridge arm is at the current inflow end, the state is -1 when the phase bridge arm is at the current outflow end, and the state is 0 when the phase bridge arm has no current. The Hall code and the bridge arm state are related to the sensor arrangement position and the current conduction sequence, and Table 2 schematically shows one of the corresponding modes.

[0136] Table 2

[0137]

[0138] Step 2.6, a control instruction model of the three-axis turntable in the control field is constructed, the control instruction model generates a theoretical rotation angle signal of a three-axis turntable mechanical model, and outputs to a PID controller model. The theoretical rotation angle signal of the three-axis turntable mechanical model can include respective ideal position signals of a base model, an azimuth axis model, a pitch axis model, and a roll axis model, i.e., theoretical rotation angle signals.

[0139] Step 2.7, a sensor model of the three-axis turntable in the control field is constructed. The sensor model input interface receives a current signal from the motor model and a three-axis turntable actual rotation angle signal and a rotation speed signal from the three-axis turntable mechanical model, generates a current signal, a rotation angle signal, and a rotation speed signal, and outputs to the PID controller model via the output interface. The sensor model can be further decomposed into a current sensor, a rotation speed sensor, a rotation angle sensor, and a Hall sensor according to user selection. Among them, the brushless direct current motor adopts a Hall sensor to detect the rotor magnetic field position to provide a position signal for rotor commutation. For example, three Hall sensors can be arranged at 120 degrees on the stator phase, output high level when the Hall sensor detects the N pole of the rotor, and output low level when the S pole of the rotor is detected. The correspondence between the detection code and the rotor position is shown in Table 2.

[0140] Step 2.8, a PID controller model of the three-axis turntable in the control field is constructed, the PID controller model receives a theoretical rotation angle signal (i.e., an ideal position signal) of a three-axis turntable mechanical model from the control instruction model, and receives a current signal, a rotation speed signal, and a rotation angle signal from the sensor model, and obtains a control signal through control algorithm calculation, and outputs to a conversion circuit model. The control equation of the PID controller model is

[0141]

[0142] Wherein, error(t) is a control deviation, t is a time, f(error) is a control signal calculated through a control algorithm, k P is a proportional control coefficient, k I is an integral control coefficient, k D is a differential control coefficient.

[0143] The PID controller model can be further decomposed into a PID controller and a PI controller according to user selection.

[0144] Step 3, a three-axis turntable mechanical model, an electrical model and a control model are built according to the unit component model, the connection between the signal flows of the unit component model and the modules of the modeling field is completed, and a Modelica-based three-axis turntable multi-field simulation system is obtained.

[0145] Step 4, interface matching and parameter adjustment are performed, different motion process parameters are set for the Modelica-based three-axis turntable multi-field simulation system, simulation tests are performed, and simulation test results are obtained. The simulation test results can be used for the optimal design of the three-axis turntable.

[0146] Referring to Figures 5 to 7 , one specific embodiment of the Modelica-based three-axis turntable multi-field simulation system provided according to the embodiments of the present application is described below. This embodiment focuses on evaluating the acceleration performance, control accuracy and reaction time of the Modelica-based three-axis turntable multi-field simulation system under control instructions. In this embodiment, based on the generality mentioned in the present application, first, each component of the three-axis turntable is set, the three-axis turntable reducer model is selected as a worm and worm gear type, the transmission ratio is 180, the motor model is selected as a permanent magnet DC motor type, and the PID controller model is selected as a PID three-loop controller; the theoretical rotation angle signals of the azimuth axis, the pitch axis and the roll axis are required to be the same ramp signal, the actual rotation angle reaches 5 rad at 5 seconds, and is maintained to 10 seconds, and the simulation ends. As shown in Figures 5 to 7 , the theoretical rotation angle signals and the actual rotation angle signals of the azimuth axis, the pitch axis and the roll axis of the three-axis turntable are shown, and the movements of the three shafts of the turntable can well track the theoretical rotation angle signals. When the turntable starts and stops, the actual rotation angle signal appears a small tracking error, but the maximum tracking error is not more than 0.8°; the actual rotation angle signal tracking accuracy is better than 0.05° in the acceleration stage under the ramp signal; after reaching the theoretical rotation angle signal 5 rad, the final steady-state tracking error of the turntable is 0; the above simulation results meet the requirements for the rotation angle adjustment speed and accuracy of the turntable.

[0147] All the above optional technical solutions can be combined in any manner to form optional embodiments of the present application, which will not be described here one by one.

[0148] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the application.

[0149] The above description is only a preferred embodiment of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered within the protection scope of the application.

Claims

1. The three-axis turntable multi-domain simulation system based on Modelica is characterized by: include: The modeling domain of the three-axis turntable built based on Modelica includes mechanical, electrical and control domains; The mechanical field includes a three-axis turntable mechanical model as the actual moving part of the three-axis turntable, a reducer model providing a reduced speed signal and an amplified torque signal, and a coupling model; The electrical field includes a motor model that provides the torque signal required by the three-axis turntable, a drive circuit model that provides a power voltage source, and a conversion circuit model that provides the converted voltage signal to the motor model; The control field includes a control instruction model that provides a theoretical rotation angle signal instruction, a PID controller model that calculates and provides the control instructions required by the conversion circuit model, and a sensor model that collects and feeds back the signals required by the PID controller model; The three-axis turntable mechanical model is configured to receive the decelerated torque signal and speed signal from the reducer model, generate the actual rotation angle signal and speed signal of the three-axis turntable, and output them to the sensor model; The reducer model is configured to receive a torque signal and a speed signal from the motor model, generate a decelerated torque signal and a speed signal, and output the decelerated torque signal and the speed signal to the three-axis turntable mechanical model; The motor model is configured to receive the converted voltage signal and current signal from the conversion circuit model, generate a torque signal, a speed signal, and a current signal, and output the torque signal and the speed signal to the reducer model, and output the current signal to the sensor model; The driving circuit model is configured to generate a voltage signal and a current signal and output the signals to the conversion circuit model; The conversion circuit model is configured to receive a voltage signal and a current signal from the drive circuit model, and a control signal from the PID controller model, generate a converted voltage signal and a converted current signal, and output the converted voltage signal and current signal to the motor model; The control instruction model is configured to generate a theoretical rotation angle signal of the three-axis turntable and output the signal to the PID controller model; The PID controller model is configured to receive a theoretical rotation angle signal of the three-axis turntable from the control instruction model, and receive a current signal, a rotation angle signal, and a rotation speed signal from the sensor model, generate a control signal, and output the control signal to the conversion circuit model; The sensor model is configured to receive current signals from the motor model and actual rotation angle signals and rotation speed signals of the three-axis turntable from the three-axis turntable mechanical model, generate current signals, rotation angle signals and rotation speed signals, and output them to the PID controller model.

2. The method for constructing a three-axis turntable multi-domain simulation system based on Modelica according to claim 1, characterized in that: include: Step 1: Model the three-axis turntable based on Modelica and determine the modeling domain and unit components of the three-axis turntable; Step 2: Build unit component models for each modeling area of ​​the three-axis turntable, determine the data signal transmission method within the component to define the interface; Step 3: Build the mechanical model, electrical model, and control system of the three-axis turntable based on the unit component model, complete the signal flow connection between each unit component model and the modules of each modeling domain, and obtain the three-axis turntable multi-domain simulation system based on Modelica; Step 4: Perform interface matching and parameter adjustment, set different motion process parameters for the Modelica-based three-axis turntable multi-domain simulation system, and conduct simulation tests; Wherein, step 1 specifically includes the following steps: Step 1.1: Model the three-axis turntable based on Modelica, and set the modeling domains of the three-axis turntable to include mechanical domain, electrical domain, and control domain; Step 1.2, setting up the three-axis turntable in the mechanical field includes: three-axis turntable mechanical model, reducer model and coupling model; Step 1.3, set up the three-axis turntable in the electrical field, including: motor model, drive circuit model and conversion circuit model; Step 1.4, setting the three-axis turntable in the control field includes: control instruction model, PID controller model and sensor model.

3. The construction method according to claim 2, characterized in that Step 2 specifically includes the following steps: Step 2.1: Construct a mechanical model of a three-axis turntable in the mechanical field, and associate the mechanical model with a standard three-dimensional geometry file so that the mechanical model acquires the properties of the geometric model. The mechanical model receives the decelerated torque signal and speed signal from the reducer model, generates the actual rotation angle signal and speed signal of the three-axis turntable, and outputs them to the sensor model. Step 2.2, constructing a reducer model of the three-axis turntable in the mechanical field, the reducer model receives the torque signal and speed signal output by the motor model, converts them, and outputs the converted torque signal and speed signal to the three-axis turntable mechanical model; Step 2.3: Construct a motor model of the three-axis turntable in the electrical field. The motor model receives the converted voltage and current signals from the conversion circuit model, generates torque and speed signals, and outputs them to the reducer model, and generates current signals and provides them to the sensor model. Step 2.4: construct a driving circuit model of the three-axis turntable in the electrical field to provide voltage and current signals for the conversion circuit model; Step 2.5: Construct a conversion circuit model for the three-axis turntable in the electrical field. The conversion circuit model generates converted voltage and current signals based on the control signal provided by the PID controller model and the voltage and current signals provided by the drive circuit model, and outputs them to the motor model to control the output torque and speed signals of the motor model. Step 2.6: Construct a control instruction model for the three-axis turntable in the control domain. The control instruction model generates a theoretical rotation angle signal of the three-axis turntable mechanical model and outputs it to the PID controller model. Step 2.7: Construct a sensor model for the three-axis turntable in the control domain. This sensor model receives the current signal from the motor model and the actual rotation angle and speed signals of the three-axis turntable from the three-axis turntable mechanical model, generates current signals, rotation angle signals, and speed signals, and outputs them to the PID controller model. Step 2.8, determine and construct the PID controller model of the three-axis turntable in the control field. The PID controller model obtains the control signal through calculation of the control algorithm based on the theoretical angle signal of the three-axis turntable mechanical model received from the control instruction model, and the current signal, speed signal and angle signal received from the sensor model, and outputs it to the conversion circuit model.

4. The construction method according to claim 3, characterized in that Step 2.2 specifically includes the following steps: Step 2.2.1, the equation for constructing the reducer model is: T m =T J-in +J J-in α J-in +T f-in iT f-in =T J-out +J J-out α J-out +T f-out T f-in =T c-in sign(w J-in )+B J-in w J-in T f-out =T c-out sign(w J-out )+B J-out w J-out In J-in =iw J-out Among them, i is the transmission ratio of the reducer, T m is the motor input torque, T J-in is the reducer input torque, T J-out is the output torque of the reducer, T f-in is the friction torque at the reducer input end, T f-out is the friction torque at the output end of the reducer, w J-in is the speed of the reducer input end, w J-out is the speed of the reducer output end, α J-in is the angular acceleration of the reducer input, α J-out is the angular acceleration of the reducer output, J J-in is the moment of inertia of the reducer input end, J J-out is the moment of inertia of the reducer output end, T c-in is the static friction torque at the reducer input end, T c-out is the static friction torque at the output end of the reducer, B J-in is the damping coefficient of the reducer input end, B J-out is the damping coefficient of the reducer output, sign(·) is the sign function; Step 2.2.2, determine the type of reducer model. If it is a worm gear reducer model or a spur gear reducer model, proceed to step 2.2.

3. Otherwise, it is a direct drive model, proceed to step 2.

3. In step 2.2.3, determine whether the reducer model is a worm gear model or a spur gear model, introduce a coupling model, and convert the torque signal and speed signal received from the motor model into the coupling model. The converted torque signal and speed signal are then output to the reducer model. The coupling model is constructed as follows: T L-out =K L (i L-in -θ L-out ) T m -T L-out =J L α L-out +B L w L-out Among them, T L-out is the coupling output torque, θ L-in is the coupling input angle, θ L-out is the coupling output angle, K L is the torsional stiffness of the coupling, w L-out is the coupling output speed, α L-out is the coupling output angular acceleration, J L is the moment of inertia of the coupling output end, B L is the damping coefficient of the coupling output end.

5. The construction method according to claim 4, characterized in that Step 2.3 specifically includes the following steps: Step 2.3.1, determine the type of motor model. If it is a permanent magnet DC motor, proceed to step 2.3.2; otherwise, if it is a brushless DC motor, proceed to step 2.3.

3. Step 2.3.2, the equation for constructing the permanent magnet DC motor model is: T m =C e I e=K m In m Where U is the motor applied voltage, I is the motor current, R is the motor armature resistance, L is the motor armature inductance, e is the armature back electromotive force, T e is the motor shaft output torque, T L is the motor shaft load torque, J m is the motor shaft moment of inertia, B m is the motor damping coefficient, w m is the motor rotation angle, K m is the motor back electromotive force constant, C e is the motor torque constant; then proceed to step 2.4; Step 2.3.3, the equation for constructing the brushless DC motor model is: P e =e A and A +e B and B +e C and C Among them, U A 、U B 、U C are the terminal voltages of the three-phase windings, i A 、i B 、i C They are the terminal currents of the three-phase windings, R A 、R B 、R C They are the resistance of the three-phase windings, L A 、L B 、L C are the inductance of the three-phase winding, e A 、e B 、e C They are the back electromotive force of the three-phase winding, T e is the motor shaft output torque, T L is the motor shaft load torque, J m is the motor shaft moment of inertia, B m is the motor damping coefficient, w m is the motor rotation angle, P e is the motor power.

6. The construction method according to claim 5, characterized in that: Step 2.5 specifically includes the following steps: Step 2.5.1, determine the type of motor model. If it is a permanent magnet DC motor model, proceed to step 2.5.2; otherwise, if it is a brushless DC motor model, proceed to step 2.5.

3. In step 2.5.2, the motor model is a permanent magnet DC motor model, and the conversion circuit model uses a DC-DC transformer model to provide the voltage signal required by the motor model. Then proceed to step 2.

6. Step 2.5.3, the motor model is a brushless DC motor model, and the conversion circuit model uses a three-phase full-bridge inverter model to convert the DC voltage signal received from the drive circuit model into the voltage signal required by the motor model. The three-phase full-bridge inverter includes six bridge arms: the first bridge arm AR, the second bridge arm AL, the third bridge arm BR, the fourth bridge arm BL, the fifth bridge arm CR and the sixth bridge arm CL.

7. The construction method according to claim 3, characterized in that: The theoretical rotation angle signal of the three-axis turntable mechanical model in step 2.6 includes the theoretical rotation angle signals of the base model, azimuth axis model, pitch axis model and roll axis model respectively.

8. The construction method according to claim 3, characterized in that: The sensor model of the three-axis turntable in the control field constructed in step 2.7 includes a current sensor, a speed sensor, a rotation angle sensor, and a Hall sensor.

9. The construction method according to claim 3, wherein: Step 2.8 involves constructing the control equations of the PID controller model of the three-axis turntable in the control domain: Among them, error(t) is the control deviation, t is the time, f(error) is the control signal calculated by the control algorithm, k P is the proportional control coefficient, k I is the integral control coefficient, k D is the differential control coefficient.

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