Generalized Modular Modeling and Simulation Method and System for Electric Steering Gear System

Abstract

The present invention relates to a new generation of information technology, and discloses a general modular modeling and simulation method and system for an electric steering gear system, so as to solve the problems of poor model generality and scalability of existing simulation methods. The present invention adopts an object-oriented design method, and through modular modeling, a general steering gear system simulation model is created, which can be compatible with both brushed and brushless electric steering gear systems. First, according to the common functional components of the electric steering gear system, simulation models of the functional class members are respectively established, and their key driving parameters are created; then a unified external input / output interface is defined, and the activation and inhibition states of the interface are changed by calling logical expressions and class attributes, and the interfaces in the activated state of the above simulation modules are connected according to the data flow direction; finally, the connected simulation modules are further encapsulated and a user interaction window is created for the user to select the type of steering gear system and change the key driving parameters.

Description

Technical Field

[0001] The present invention relates to computer methods and systems based on specific computational models in the new generation of information technology, and particularly to a general modular modeling and simulation method and system for an electric servo system. Background Art

[0002] A servo is an actuator for position servo, which is widely used in various fields such as unmanned aerial vehicles, robots, ships, etc. Its function is to output a signal of a certain magnitude and polarity after receiving a control instruction, drive the output shaft of the servo to deflect, thereby generating a torque of a certain magnitude. According to the energy type, it can be divided into pneumatic servo, hydraulic servo and electric servo. Since the electric servo overcomes the disadvantages of complex structure and inconvenient maintenance of the hydraulic servo and pneumatic servo, and its characteristics such as high control accuracy and fast response speed are more widely used. The electric servo system mainly includes two types: brushed and brushless, and mainly consists of three parts: a servo body, a servo controller and a drive circuit. Using simulation technology to guide the design and parameter tuning of the servo, master the dynamic characteristics of the servo, and realize the evaluation of the servo performance and the optimization of the control algorithm has important significance.

[0003] At present, the modeling and simulation of the servo system are mostly for a specific type of servo, and a complex simulation model is built by calling basic controls in the simulation software. This method has poor versatility and scalability. When the type and parameters of the servo change, it is necessary to disconnect the connection relationship, call the controls, and configure the parameters to rebuild the model. At present, the electric servo system consists of more than 100 basic controls in two major categories, and the modeling process is complex and error-prone. Obviously, the existing methods cannot meet the general design requirements. Summary of the Invention

[0004] The purpose of the present invention is to disclose a general modular modeling and simulation method and system for an electric servo system to solve the problem of poor versatility and scalability of the existing simulation method model.

[0005] To achieve the above object, the present invention discloses a general modular modeling and simulation method for an electric servo system, including:

[0006] Step S1, establish three modular simulation models corresponding to the controller, the driver and the motor respectively. The external interfaces of each modular simulation model include: partial interfaces only adapted to the brushed servo system, partial interfaces only adapted to the brushless servo system, and common interfaces of the brushed servo system and the brushless servo system; and establish the mapping relationship between each interface and the two types of servo systems, namely brushed and brushless, so that: when the brushed servo system is selected, the interfaces unique to the brushless servo system are suppressed, and the remaining interfaces are activated; on the contrary, when the brushless servo system is selected, the interfaces unique to the brushed servo system are suppressed, and the remaining interfaces are activated;

[0007] Step S2: Establish the signal processing logic between the corresponding interfaces inside each of these modular simulation models under the brushed rudder system and the brushless rudder system respectively;

[0008] Step S3: According to the data flow direction, connect the corresponding interfaces between each pair of these modular simulation models under the brushed rudder system and the brushless rudder system respectively, and then encapsulate them into a unified general model, and create a user interaction window for the user to select the type of the rudder system of the global variable, and change the parameters of the internal processing logic of each of these modular simulation models in the type of the rudder system selected by the user to achieve simulation.

[0009] Preferably, the controller is compatible with both the brushed and brushless rudder systems; two types of objects are instantiated for the driver respectively: an H-bridge driver suitable for the brushed rudder system composed of 4 MOSFETs or IGBTs, and a three-phase bridge driver suitable for the brushless rudder system composed of 6 MOSFETs or IGBTs; two types of objects are instantiated for the motor respectively: a brushed motor using mechanical commutation, and a brushless motor using electronic commutation.

[0010] Preferably, in the brushed rudder system corresponding to the step S2, the controller adopts a PID control algorithm Combine with a triangular wave signal with a set frequency to generate a PWM signal, output limit, and act on the 4 switches of the H-bridge of the rear-end driver. Among them, K P is the proportional coefficient, K I is the integral coefficient, K D is the differential coefficient, θ is the rudder deflection angle, Δθ is the difference between the displacement of the set rudder deflection angle and the actual output angular displacement of the steering gear, and u is the output of the controller.

[0011] Preferably, in the brushed rudder system corresponding to the step S2, change the on-off time of the switch by the duty cycle of the PWM signal to adjust the input voltage of the motor. The 4 MOSFETs or IGBTs are Q1, Q2, Q3, and Q4 respectively; among them, Q1 and Q4 are turned on simultaneously, and the motor rotates forward; Q2 and Q3 are turned on simultaneously, and the motor rotates backward; and through logical inversion, it is ensured that: Q1 and Q2 cannot be turned on simultaneously, and Q3 and Q4 cannot be turned on simultaneously to prevent a short circuit of the power supply.

[0012] Preferably, in the internal signal processing logic of the motor in the brushed rudder system corresponding to the step S2, it includes: the voltage balance equation of the motor winding circuit, the mechanical equation of the rotor, and the electromagnetic torque equation E a =b m ω; T = K m i; where R a is the armature resistance, L a is the armature inductance, bm is the back electromotive force constant, J is the moment of inertia, K m is the torque coefficient, u is the voltage, i is the current, T m is the externally applied load torque, T is the output torque, ω is the angular velocity, E a is the back electromotive force.

[0013] To achieve the above object, the present invention also discloses a general-purpose modular modeling and simulation system for an electric steering gear system, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the above method is implemented.

[0014] The present invention has the following beneficial effects:

[0015] Based on the object-oriented design method, the present invention creates a general steering system simulation model through modular modeling, which can be compatible with both brushed and brushless electric steering gear systems. First, according to the common functional components of the electric steering gear system, the simulation models of the functional class members are established respectively, and their key driving parameters are created; then a unified external input / output interface is defined, and the activation and inhibition states of the interface can be changed by calling logical expressions and class attributes, and the interfaces of the above simulation modules in the active state are connected according to the data flow direction; finally, the connected simulation modules are further encapsulated and a user interaction window is created for the user to select the steering system type and change the key driving parameters. Thereby, the present invention uses a software-defined model to solve the problems of lack of generality and scalability of the existing simulation method models, simplifies the design operation process, and improves the design efficiency.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0018] Figure 1 is the general simulation model and user interaction window of the electric steering gear system disclosed in the embodiment of the present invention.

[0019] Figure 2 is the corresponding relationship between the simulation method class and the object disclosed in the embodiment of the present invention.

[0020] Figure 3 is the modular modeling and simulation model of the brushed steering system disclosed in the embodiment of the present invention.

[0021] Figure 4 is part of the S-Function driver program in the simulation method disclosed in the embodiment of the present invention.

[0022] Figure 5 This is the simulation model of the Controller disclosed in the embodiments of the present invention.

[0023] Figure 6 This is the simulation model of the Brushed Rudder System Driver disclosed in the embodiments of the present invention.

[0024] Figure 7 This is the simulation model of the Brushed DC Motor (BDC) disclosed in the embodiments of the present invention.

[0025] Figure 8 is the simplified general simulation model and user interaction window after deleting the suppression interface for Figure 1 .

[0026] Figure 9 is the simplified general simulation model and user interaction window after switching to the Brushless Rudder System.

[0027] Figure 10 is the simplified modular modeling and simulation model of the Brushed Rudder System after deleting the suppression interface for Figure 3 .

[0028] Figure 11 is the simplified modular modeling and simulation model of the Brushless Rudder System relative to Figure 10 . Detailed implementation manners

[0029] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the claims.

[0030] Embodiment 1

[0031] This embodiment discloses a general modular modeling and simulation method for an electric rudder system, including the following steps:

[0032] Step 1: As Figure 2 , the electric rudder system has two types: the brushed rudder system and the brushless rudder system, both of which are composed of three functional modules: a controller, a driver, and a motor. According to the working principle, the external input and output interfaces are unified, and the modular simulation models of the above three components are established. The external interfaces of the three components of the brushed rudder system and the brushless rudder system are shown in Table 1:

[0033] Table 1 Rudder System External Interfaces

[0034]

[0035]

[0036] In this step, the specific division of labor among the three types of components, namely the controller, the driver, and the motor, is as follows: The controller completes the calculation of computer input instructions and feedback instructions and the implementation of algorithms; the driver adjusts the motor phase voltage according to the PWM signal output by the controller; the motor, as the actuator, changes the torque and output speed according to the voltage change to reach the specified position or speed.

[0037] Step 2: Define the interfaces of the three types of components (i.e., the three modular simulation models) according to Step 1, and change the activation and inhibition states of the interfaces by calling logical expressions and class attributes. Set the global variable Motor_Tpye, which is defined as the type of steering system. When the variable Motor_Tpye is 0, it is a brushless steering system; when the variable Motor_Tpye is 1, it is a brushed steering system. As Figure 4 shown, establish an S-fuction function to implement class instantiation and object calling, and initialize the attribute parameters of the object, with the initial values all being 0.

[0038] When the brushed steering system is selected, the corresponding interface is activated, while the corresponding interface variables of the brushless steering system are inhibited and cannot be connected. At this time, establish a modular simulation model of the brushed steering system for simulation, as Figure 3 shown.

[0039] When the brushless steering system is selected, the corresponding interface variables of the brushless steering system are activated, and at this time, establish a modular simulation model of the brushless steering system for simulation.

[0040] Step 3: Establish the signal processing logic between the corresponding interfaces within each of the modular simulation models for the brushed steering system and the brushless steering system respectively.

[0041] In this step, the above three types of components include the common features and functions of all objects, and instantiate them respectively. Optionally, the controller is compatible with both brushed and brushless steering systems. The driver instantiates two types of objects: ① The H-bridge driver, which consists of 4 MOSFETs or IGBTs and is suitable for the brushed steering system; ② The three-phase bridge driver, which consists of 6 MOSFETs or IGBTs and is suitable for the brushless steering system. The motor instantiates two types of objects: ① The brushed motor, which uses mechanical commutation; ② The brushless motor, which uses electronic commutation. Taking the brushed steering system as an example, the signal processing logic between the corresponding interfaces of each functional module is as follows:

[0042] The controller in this embodiment, as Figure 5 shown, can adopt the classic PID control algorithm to generate a PWM signal in combination with a triangular wave signal with a period of 100Hz, and output limiting, which acts on the 4 switches of the H-bridge at the rear end of the driver, where K P is the proportional coefficient, K I is the integral coefficient, K Dis the differential coefficient, θ is the rudder deflection angle, Δθ is the difference between the displacement of the set rudder deflection angle and the actual output angular displacement of the steering gear, and u is the output of the controller.

[0043] As Figure 6 shown, for the brushed rudder system, the driver in this embodiment can adopt an H-bridge circuit driving structure, which is composed of 4 MOSFETs. By changing the on-off time of the switch through the duty cycle of the PWM signal, the input voltage of the motor can be adjusted. Q1 and Q4 are turned on simultaneously, and the motor rotates forward; Q2 and Q3 are turned on simultaneously, and the motor rotates backward. Through logical inversion, it is ensured that Q1 and Q2, Q3 and Q4 cannot be turned on simultaneously to prevent power short-circuit.

[0044] As Figure 7 shown, in this embodiment, a simulation model of the brushed motor can be created by establishing the voltage balance equation of the motor winding circuit, the mechanical equation of the rotor, and the electromagnetic torque equation. The internal data processing logic usually includes: E a = b m ω; T = K m i; where, R a is the armature resistance, L a is the armature inductance, b m is the back electromotive force constant, J is the moment of inertia, K m is the torque coefficient, u is the voltage, i is the current, T m is the externally applied load torque, T is the output torque, ω is the angular velocity, E a is the back electromotive force.

[0045] The key driving parameters used in this step are shown in Table 2.

[0046] Table 2 Key Driving Parameters of the Rudder System

[0047]

[0048] Among them, R on 、R d 、V f 、R s and C s are the configuration parameters of the driver field effect transistor, which are related to the driving ability of the driver; J, F, P, T f 、R a 、L a and K m are the inherent property parameters of the motor. As important properties of the object, the parameters are used to store data and drive the data flow. In this embodiment, the parameters correspond one-to-one with the actual parameters; moreover, in this embodiment, the object-oriented design method can be used to call with the "object.method()" and "object.property() =" configurations.

[0049] Step 4: As Figure 1 shown, further encapsulate the Figure 3 connected simulation model, and create a user interaction window to select the type of steering system and change the key driving parameters, so as to obtain a general and extensible simulation model of the electric steering gear system. Thereby, after the user calls this general simulation model, they can flexibly and conveniently select the type of steering system and modify the key driving parameters according to different task requirements; the operation process is simplified, and the resource utilization rate and simulation efficiency are improved.

[0050] In this embodiment, the above Figure 1 When the user selects a brushed steering gear system, the encapsulation interface essentially corresponds to Figure 8 ; and when the user switches to a brushless steering gear system, the encapsulation interface essentially corresponds to Figure 9 . In the next-level display section after the click operation, similarly, Figure 3 If the suppressed interfaces are deleted from the circuit connection relationship shown in the display interface, the simplified diagram thereof is Figure 10 ; on the contrary, if in the next-level display interface corresponding to the brushless steering gear system, the simplified diagram thereof is Figure 11 .

[0051] Embodiment 2

[0052] Corresponding to the above embodiment, this embodiment discloses a general modular modeling and simulation system for an electric steering gear system, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the above method is implemented, and its core steps include:

[0053] Step S1: Establish three modular simulation models corresponding to the controller, the driver, and the motor respectively. The external interfaces of each modular simulation model include: some interfaces only adapted to the brushed steering system, some interfaces only adapted to the brushless steering system, and common interfaces for the brushed and brushless steering systems; and establish the mapping relationship between each interface and the two types of steering systems, namely brushed and brushless, so that: when the brushed steering system is selected, the interfaces unique to the brushless steering system are suppressed, and the remaining interfaces are activated; on the contrary, when the brushless steering system is selected, the interfaces unique to the brushed steering system are suppressed, and the remaining interfaces are activated.

[0054] Step S2: Establish the signal processing logic between the interfaces corresponding to the brushed steering system and the brushless steering system respectively inside each modular simulation model.

[0055] Step S3: According to the data flow direction, connect the corresponding interfaces between each pair of the modular simulation models under the brushed rudder system and the brushless rudder system respectively, and then encapsulate them into a unified general model, and create a user interaction window for the user to select the type of the rudder system of the global variable and change the parameters of the internal processing logic of each modular simulation model in the type of the rudder system selected by the user to implement the simulation.

[0056] For the specific implementation of each step, refer to the above embodiments and will not be elaborated.

[0057] In summary, the general modular modeling and simulation method and system of the electric rudder system respectively disclosed in the embodiments of the present invention are based on the object-oriented design method. Through modular modeling, a general rudder system simulation model is created, which can be compatible with the brushed and brushless electric rudder systems. First, according to the common functional components of the electric rudder system, establish the simulation models of the functional class members respectively, and create their key drive parameters; then define a unified external input and output interface, and the activation and inhibition states of the interface can be changed by calling logical expressions and class attributes. Connect the interfaces in the active state of the above simulation modules according to the data flow direction; finally, further encapsulate the connected simulation modules and create a user interaction window for the user to select the type of the rudder system and change the key drive parameters. Therefore, the present invention uses a software-defined model to solve the problems of lack of universality and scalability of the existing simulation method models, simplifies the design operation process, and improves the design efficiency.

[0058] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A general modular modeling and simulation method for an electric steering gear system, characterized in that Including: Step S1: Establish three modular simulation models corresponding to the controller, the driver, and the motor respectively. The external interfaces of each modular simulation model include: partial interfaces only adapted to the brushed steering system, partial interfaces only adapted to the brushless steering system, and common interfaces of the brushed and brushless steering systems; and establish the mapping relationships between each interface and the two types of steering systems, namely brushed and brushless, so that: when the brushed steering system is selected, the interfaces unique to the brushless steering system are suppressed, and the remaining interfaces are activated; on the contrary, when the brushless steering system is selected, the interfaces unique to the brushed steering system are suppressed, and the remaining interfaces are activated. Step S2: Establish the signal processing logic between the corresponding interfaces inside each modular simulation model under the brushed and brushless steering systems respectively. Step S3: Connect the corresponding interfaces between each pair of modular simulation models under the brushed and brushless steering systems respectively according to the data flow direction, and then encapsulate them into a unified general model, and create a user interaction window for the user to select the type of the steering system of the global variable, and change the parameters of the internal processing logic of each modular simulation model in the type of steering system selected by the user to implement the simulation.

2. The method according to claim 1, characterized in that, The controller is compatible with both brushed and brushless steering systems; the driver instantiates two objects respectively: an H-bridge driver composed of 4 MOSFETs or IGBTs and applicable to the brushed steering system, and a three-phase bridge driver composed of 6 MOSFETs or IGBTs and applicable to the brushless steering system; the motor instantiates two objects respectively: a brushed motor using mechanical commutation, and a brushless motor using electronic commutation.

3. The method according to claim 2, characterized in that In the brushed rudder system corresponding to the step S2, the controller adopts a PID control algorithm Combined with a triangular wave signal with a set frequency period to generate a PWM signal, with output limiting, acting on the 4 switches of the H-bridge of the rear-end driver, where K P is the proportionality coefficient, K I is the integral coefficient, K D is the differential coefficient, θ is the rudder deflection angle, Δθ is the difference between the displacement of the set rudder deflection angle and the actual output angular displacement of the steering gear, and u is the output of the controller.

4. The method according to claim 2, wherein In the brushed steering system corresponding to Step S2, the on-off time of the switch is adjusted by changing the duty cycle of the PWM signal to regulate the input voltage of the motor. The 4 MOSFETs or IGBTs are Q1, Q2, Q3, and Q4 respectively; among them, Q1 and Q4 are conducted simultaneously, and the motor rotates forward; Q2 and Q3 are conducted simultaneously, and the motor rotates backward; and through logical inversion, it is ensured that: Q1 and Q2 cannot be conducted simultaneously, and Q3 and Q4 cannot be conducted simultaneously to prevent power short circuit.

5. The method according to claim 2, wherein In the brushed steering system corresponding to the step S2, the internal signal processing logic of the motor includes: the voltage balance equation of the motor winding circuit, the mechanical equation of the rotor, and the electromagnetic torque equation: T = K m i; where R a is the armature resistance, L a is the armature inductance, b m is the back electromotive force constant, J is the moment of inertia, K m is the torque coefficient, u is the voltage, i is the current, T m is the applied load torque, T is the output torque, ω is the angular velocity, E a is the back electromotive force; θ is the rudder angle.

6. A general modular modeling and simulation system for an electric steering gear system, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method according to any one of claims 1 to 5 above.

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