Modeling method of hybrid power loader

Abstract

The invention relates to the technical field of vehicles, and particularly discloses a modeling method of a hybrid power loader, which comprises the following steps of: S10, establishing a whole-vehicle multi-body model, an electric drive system model and a hydraulic system model of the loader according to design parameters of the loader; s20, the loader whole-vehicle multi-body model, the electric drive system model and the hydraulic system model are coupled, and information interaction among the three models is achieved; and S30, a loader control system is established, and accurate control over the whole-vehicle multi-body model, the electric drive system model and the hydraulic system model of the loader is achieved. Modeling is conducted through the modeling method, a loading machine whole-vehicle multi-body model, an electric drive system model and a hydraulic system model are coupled through simulation software, information interaction among the three models is achieved, and then the loading machine whole-vehicle multi-body model, the electric drive system model and the hydraulic system model are obtained by calling a control strategy in a loading machine control system. And therefore, cooperative work among the whole-vehicle multi-body model, the electric drive system model and the hydraulic system model of the loader can be realized, and comprehensive simulation verification can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of vehicles, and in particular to a modeling method for a hybrid power loader. Background Art

[0002] Construction machinery is a complex system with a high degree of mechanical, electrical and hydraulic integration. Its research and development process faces practical problems such as high cost, long cycle and low efficiency of actual vehicle testing.

[0003] With the development of simulation technology, the model-based whole machine development method is an effective technical solution. However, the existing research in the field of engineering machinery is mostly based on single-category system modeling methods, such as the modeling of working devices and hydraulic systems, which can effectively support the control strategy development and verification analysis of hydraulic operation systems.

[0004] However, the above settings do not take into account the coupling effect between multiple types of systems. As a special wheeled vehicle integrating mechanical, electrical and hydraulic functions, the distributed four-wheel drive loader has an incomplete modeling method, which makes it impossible to accurately judge the synergy between multiple types of systems and conduct a comprehensive simulation verification of the whole machine.

[0005] Therefore, a modeling method for hybrid loaders is urgently needed to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide a modeling method for a hybrid power loader to solve the problem that the simulation model of the existing hybrid power loader in the related technology does not take into account the coupling effect between multiple categories of systems, and thus cannot accurately judge the synergy between multiple categories of systems and cannot perform comprehensive simulation verification of the entire machine.

[0007] The present invention provides a modeling method for a hybrid power loader, and the modeling method for a hybrid power loader comprises:

[0008] S10: According to the design parameters of the loader, a multi-body model of the loader, an electric drive system model and a hydraulic system model are established;

[0009] S20: coupling the loader vehicle multi-body model, the electric drive system model and the hydraulic system model, and realizing information interaction among the three;

[0010] S30: Establishing a loader control system to achieve precise control of the loader vehicle multi-body model, the electric drive system model and the hydraulic system model.

[0011] As a preferred technical solution for the modeling method of a hybrid power loader, the establishment of the multi-body model of the loader vehicle specifically includes:

[0012] A10: Building a multi-body model of the loader vehicle through modeling software according to the design parameters;

[0013] A11: Transfer the loader vehicle multi-body model to the Simscape toolbox in Matlab;

[0014] A12: Use the magic tire module and tire property file provided by the Simscape toolbox in Matlab to define the tire properties in the loader vehicle multi-body model;

[0015] A13: According to different road conditions, a working road surface model in contact with the tire is established through the Infinite Plane module in the Simscape toolbox in Matlab.

[0016] As a preferred technical solution of the modeling method of the hybrid loader, before executing A12, it also includes:

[0017] A111: Use the Simscape toolbox in Matlab to verify whether the components of the loader vehicle multi-body model are set reasonably. If yes, execute A12; otherwise, execute A112;

[0018] A112: Adjust the unreasonable components in the multi-body model of the loader vehicle and execute A11.

[0019] As a preferred technical solution for the modeling method of a hybrid loader, the establishment of the electric drive system model specifically includes: using the integrated module in the Simscape toolbox in Matlab, inputting the loader design parameters into the integrated module to achieve modeling of the electric drive system model.

[0020] As a preferred technical solution for the modeling method of the hybrid loader, the establishment of the electric drive system model specifically further includes: using the engine module in the Simscape toolbox in Matlab to establish the speed regulation characteristics of the engine model in the electric drive system model.

[0021] As a preferred technical solution of the modeling method of the hybrid loader, the establishment of the electric drive system model specifically further includes establishing a motor asymmetry model in the electric drive system model;

[0022] Specifically include:

[0023] B10: Establishing a motor driving function and a motor braking function according to the characteristic curve corresponding to the characteristic parameters of the motor;

[0024] B20: introducing the motor drive function and the motor brake function into the Simscape toolbox in Matlab to form the motor asymmetry model;

[0025] B30: If the motor asymmetry model receives a drive command, the motor drive function is called; if the motor asymmetry model receives a brake command, the motor brake function is called.

[0026] As a preferred technical solution for the modeling method of a hybrid loader, the establishment of the electric drive system model specifically includes:

[0027] A resistor grid model is established by using an integrated module in the Simscape toolbox in Matlab to protect the battery model in the electric drive system model from overcharging;

[0028] The diode model and the capacitor model are established by using the integrated module in the Simscape toolbox in Matlab. The diode model is used to ensure the direction of the current flowing into the resistor grid model, and the capacitor model is used to ensure the stability of the current flowing into the resistor grid model.

[0029] As a preferred technical solution for the modeling method of the hybrid loader, the establishment of the hydraulic system model specifically includes:

[0030] C10: using the function module in the Simscape toolbox in Matlab, inputting the design parameters to model the brake hydraulic system, the steering hydraulic system and the working hydraulic system in the hydraulic system model;

[0031] C20: Determine whether the brake hydraulic system, the steering hydraulic system and the working hydraulic system meet the set functional requirements. If yes, execute C30; if not, execute C40;

[0032] C30: Determination of the hydraulic system model;

[0033] C40: Adjust the systems in the brake hydraulic system, the steering hydraulic system and the working hydraulic system that do not meet the functional requirements and execute C20.

[0034] As a preferred technical solution of the modeling method of the hybrid loader, S20 specifically includes:

[0035] S201: coupling the loader vehicle multi-body model, the electric drive system model and the hydraulic system model through the conversion multi-body interface in the Simscape toolbox in Matlab;

[0036] S202: Using electrical signals, physical signals and simulation signals in the Simscape toolbox in Matlab, information interaction among the loader vehicle multi-body model, the electric drive system model and the hydraulic system model is realized.

[0037] As a preferred technical solution of the modeling method of the hybrid loader, S40 is also included:

[0038] S401: Setting a command input module to simulate the driver controlling the loader to perform various actions;

[0039] S402: Use the CAN bus in the Simscape toolbox in Matlab to communicate with the command input module and the loader control system.

[0040] The beneficial effects of the present invention are:

[0041] The present invention provides a modeling method for a hybrid power loader, which includes S10: establishing a loader vehicle multi-body model, an electric drive system model and a hydraulic system model according to the loader design parameters; S20: coupling the loader vehicle multi-body model, the electric drive system model and the hydraulic system model, and realizing information interaction among the three; S30: establishing a loader control system to realize accurate control of the loader vehicle multi-body model, the electric drive system model and the hydraulic system model. When modeling is performed by the modeling method for the hybrid power loader, the loader vehicle multi-body model, the electric drive system model and the hydraulic system model are first established, and then the loader vehicle multi-body model, the electric drive system model and the hydraulic system model are coupled through simulation software, and information interaction among the three is realized, so that they can cooperate with each other and exchange information with each other, and then by calling the control strategy in the loader control system, the coordinated work between the loader vehicle multi-body model, the electric drive system model and the hydraulic system model can be realized, so as to realize comprehensive simulation verification of the hybrid power loader. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural diagram of a modeling method of a hybrid power loader in an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of the connection relationship of a hybrid power loader in an embodiment of the present invention;

[0044] Figure 3 A schematic diagram of the mechanical-electrical-hydraulic coupling of a hybrid power loader in an embodiment of the present invention;

[0045] Figure 4 A schematic diagram of the structure of the power system and operating device of the loader of the present invention;

[0046] Figure 5 This is a schematic diagram of a magic tire model in an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of a road surface model in an embodiment of the present invention;

[0048] Figure 7 This is a diagram of the asymmetric characteristic model of the motor in an embodiment of the present invention;

[0049] Figure 8 This is a schematic diagram of a resistance grid equivalent model in an embodiment of the present invention;

[0050] Fig. 9 is a flow chart of a modeling method for a hybrid power loader according to an embodiment of the present invention;

[0051] Fig.10 It is a flow chart of modeling a multi-body model of a loader vehicle in the modeling method of a hybrid power loader in an embodiment of the present invention;

[0052] Fig.11 A flow chart of modeling a motor asymmetric characteristic model in a modeling method for a hybrid power loader according to an embodiment of the present invention;

[0053] Fig.12 This is a flow chart of modeling a hydraulic system model in the modeling method of a hybrid power loader in an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0058] like Figures 1 to 12 As shown, this embodiment provides a modeling method for a hybrid power loader, and the modeling method for a hybrid power loader includes:

[0059] S10: According to the design parameters of the loader, a multi-body model of the loader, an electric drive system model and a hydraulic system model are established.

[0060] like Fig.10 As shown in the figure, the establishment of the multi-body model of the loader vehicle specifically includes:

[0061] A10: Based on the design parameters, a multi-body model of the loader vehicle is established using modeling software.

[0062] The multi-body model of the loader vehicle can be established through 3D modeling software.

[0063] Optionally, the 3D software used may be one of Creo, UG and SolidWorks.

[0064] Optionally, the loader vehicle multi-body model specifically includes a body structure, a working device, and tires, etc.

[0065] A11: Transfer the loader vehicle multi-body model to the Simscape toolbox in Matlab.

[0066] The purpose of this step is to transfer the established 3D model to the Simscape toolbox in Matlab. As a toolbox in Matlab, Simscape provides the ability to build physical models and perform multi-domain simulations. It enables users to import designs from CAD files and visualize the loader vehicle multi-body model, electric drive system model, and hydraulic system model, thereby optimizing system performance and discovering errors through simulation in the early stages of development. Simscape models can be used for virtual debugging or to create operational digital twins to support system design and optimization.

[0067] A111: Use the Simscape toolbox in Matlab to verify whether the components of the loader vehicle multi-body model are set reasonably. If so, execute A12; if not, execute A112.

[0068] In this step, unreasonable settings of various components of the loader vehicle multi-body model include: the loader working mechanism cannot move normally, and mechanism interference occurs; the cylinder model parameter settings are unreasonable, and the boom and bucket shake and cannot reach a static state; the kinematic pair settings at the hinge point of the working mechanism are unreasonable, such as the rotation pair is set as a ball joint pair, resulting in problems with the working mechanism's degree of freedom; the mass, center of mass coordinates, and moment of inertia parameters of the working mechanism's boom, bucket, draw rod, rocker arm and other components are incorrect, etc.

[0069] A112: Adjust the unreasonable components in the multi-body model of the loader vehicle and execute A11.

[0070] In this step, the adjustment of the component includes changing the shape and size of the component.

[0071] A12: Use the magic tire module and tire property file provided by the Simscape toolbox in Matlab to define the tire properties in the loader multi-body model. Figure 5As shown in the figure, tire modeling is a key link in loader modeling because it directly affects the loader's driving stability, handling performance, and the accuracy of dynamic analysis. The magic tire model can simulate the actual state of the tire with high accuracy, and its mathematical expression is relatively simple, easy to understand and implement. The interaction between the tire and the ground is usually represented by tire models, which can simulate the mechanical behavior of the tire under different working conditions, including longitudinal, lateral and vertical forces. An accurate tire model can better reflect the performance of the tire under actual working conditions, including traction, rolling resistance, lateral force, etc., thereby improving the accuracy of the overall loader simulation.

[0072] Specifically, the wheel of the loader mainly consists of two parts, the rim and the tire. The rim is directly connected to the multi-body model of the loader vehicle, and its related properties are consistent with the multi-body model of the loader vehicle. The tire-related properties are composed of the magic tire module and tire property file provided by the Simscape toolbox in Matlab. The tire parameters such as tire mass, tire radial moment of inertia, tire moment of inertia, etc. are defined in the tire property file.

[0073] A13: According to different road conditions, a working road surface model in contact with the tire is established through the Infinite Plane module in the Simscape toolbox in Matlab.

[0074] In this step, if Figure 6 As shown in the figure, the Infinite Plane module in the Simscape toolbox in Matlab can establish an infinite plane in contact with the tire. This infinite plane is the working road model to simulate the road surface. Considering that the interaction between the tire and the road surface is different under different road conditions, when modeling, the road surface can be divided into flat road surface, slope road surface and rough road surface by defining the road surface file.

[0075] Optionally, the establishment of the electric drive system model specifically includes:

[0076] By using the integrated module in the Simscape toolbox in Matlab, the loader design parameters are input into the integrated module to realize the modeling of the electric drive system model.

[0077] In this step, the electric drive system model includes the loader engine model, generator model, battery model and motor model. Using the integrated module in the Simscape toolbox in Matlab, the loader design parameters are input into the module to complete the establishment of each model of the electric drive system.

[0078] Optionally, the establishment of the electric drive system model specifically includes:

[0079] The engine module in the Simscape toolbox in Matlab is used to establish the speed regulation characteristics of the engine model in the electric drive system model.

[0080] In this step, the speed regulation characteristics of the engine refer to the speed response of the engine under different loads and its control performance. The speed regulation characteristics of the engine model are established using the engine module in the Simscape toolbox in Matlab.

[0081] Establish the motor asymmetry model in the electric drive system model;

[0082] In this step, the components of the Simscape toolbox in Matlab only support the symmetrical modeling of motor drive and braking characteristics. However, when the motor actually drives the tire to rotate, the motor drive characteristic curve and the motor braking characteristic curve are not in a symmetrical relationship. Therefore, it is necessary to establish an asymmetric model of the motor by yourself.

[0083] like Figure 7 and 11 As shown, specifically including:

[0084] B10: Establish the motor drive function and motor brake function according to the characteristic curve corresponding to the characteristic parameters of the motor.

[0085] In this step, the motor will be tested for characteristic parameters before leaving the factory, and then the corresponding characteristic curve will be provided to the user. Therefore, the corresponding motor drive function and motor brake function can be obtained according to the characteristic curve.

[0086] B20: The motor drive function and the motor brake function are introduced into the Simscape toolbox in Matlab to form a motor asymmetry model.

[0087] B30: If the motor asymmetry model receives a drive command, the motor drive function is called; if the motor asymmetry model receives a brake command, the motor brake function is called.

[0088] In this step, the starting adjustment of the motor drive function and the motor brake function is set, that is, if the motor asymmetry model receives a drive instruction, the motor drive function is called, and if the motor asymmetry model receives a brake instruction, the motor brake function is called.

[0089] like Figure 8 As shown, a resistor grid model is established using the integrated module in the Simscape toolbox in Matlab to protect the battery model in the electric drive system model from overcharging.

[0090] In this step, the resistor grid is an electronic component that is usually used in power systems as a current limiting and overvoltage protection device. In the modeling process of the hybrid loader, the resistor grid is an important component in the loader power system. The resistor grid modeling method based on the Simscape toolbox in Matlab can effectively simulate its protection function in the loader circuit. When the motor brakes when the battery is fully charged, the non-recoverable energy generated during the braking process can be consumed by the resistor grid, thereby effectively protecting the battery.

[0091] The diode model and the capacitor model are established by using the integrated module in the Simscape toolbox in Matlab. The diode model is used to ensure the direction of the current flowing into the resistor grid model, and the capacitor model is used to ensure the stability of the current flowing into the resistor grid model.

[0092] like Fig.12 As shown, optionally, the establishment of the hydraulic system model specifically includes:

[0093] C10: Use the function modules in the Simscape toolbox in Matlab to input the design parameters to model the brake hydraulic system, steering hydraulic system and working hydraulic system in the hydraulic system model.

[0094] C20: Determine whether the brake hydraulic system, steering hydraulic system and working hydraulic system meet the set functional requirements. If yes, execute C30; if not, execute C40;

[0095] C30: Hydraulic system model determination.

[0096] C40: Adjust the systems in the brake hydraulic system, steering hydraulic system and working hydraulic system that do not meet the functional requirements and execute C20.

[0097] In this step, taking the brake hydraulic system as an example, the disc brake module in the Simscape toolbox in Matlab is used to input the design parameters to model the loader brake system, and then determine whether the braking distance after the brake hydraulic system acts on the wheel at different vehicle speeds meets the required value. If it does, it means that the brake hydraulic system model meets the requirements and can be used in the next step. If it does not meet the requirements, the modeling parameters need to be adjusted, and the adjusted brake hydraulic system model needs to be retested until it meets the requirements.

[0098] S20: coupling the loader vehicle multi-body model, the electric drive system model and the hydraulic system model, and realizing information interaction among the three.

[0099] S20 specifically includes:

[0100] S201: The loader vehicle multi-body model, electric drive system model and hydraulic system model are coupled through the conversion multi-body interface in the Simscape toolbox in Matlab.

[0101] S202: Use the electrical signals, physical signals and simulation signals in the Simscape toolbox in Matlab to realize the information interaction among the loader vehicle multi-body model, the electric drive system model and the hydraulic system model.

[0102] S30: Establish a loader control system to achieve precise control of the loader vehicle multi-body model, electric drive system model and hydraulic system model.

[0103] In this step, the loader control system is mainly divided into three subsystems, including energy management strategy, traction drive strategy and brake energy recovery strategy. The purpose of energy management strategy design is to reasonably distribute the energy of the loader power source and realize efficient energy utilization under the premise of ensuring high reliability of system control and normal flow of energy flow; the purpose of traction drive strategy design is to improve operating efficiency, reduce energy consumption and ensure that the loader can maintain the best working state under different working conditions by accurately controlling the loader's electric drive system; the purpose of brake energy recovery strategy design is to recover the energy of the loader during braking under the premise of ensuring the safety of loader braking, which can reduce energy waste and improve energy utilization to a certain extent. Based on the multi-body model of the loader vehicle, the electric drive system model and the hydraulic system model, various control strategies can be designed and verified, laying a certain foundation for the subsequent research on engineering vehicle simulation experiments.

[0104] Includes S40:

[0105] S401: Setting a command input module to simulate a driver controlling the loader to perform various actions.

[0106] In this step, the command input module is set in the Simscape toolbox in Matlab, including the gear position of the loader, the engine gear position, the accelerator pedal opening, the brake pedal opening, the steering, the bucket handle and the boom handle opening, etc.

[0107] S402: Use the CAN bus in the Simscape toolbox in Matlab to communicate with the command input module and the loader control system.

[0108] In this step, the command issued by the command input module can call the control strategy in the loader control system, thereby executing the loader vehicle multi-body model, electric drive system model and hydraulic system model.

[0109] So far, if Figure 1As shown, the simulation model of the hybrid loader has been completed, which includes three parts: a hybrid loader, a loader control system and a command input module. The hybrid loader includes a loader vehicle multi-body model, an electric drive system model and a hydraulic system model.

[0110] When modeling the hybrid loader using the modeling method, first establish a loader vehicle multi-body model, an electric drive system model and a hydraulic system model, then couple the loader vehicle multi-body model, the electric drive system model and the hydraulic system model through simulation software, and realize information interaction among the three, so that they can cooperate with each other and exchange information with each other. Use the CAN bus in the Simscape toolbox in Matlab to communicate with the command input module and the loader control system, and then call the control strategy in the loader control system through the command input module, so as to realize the collaborative work among the loader vehicle multi-body model, the electric drive system model and the hydraulic system model, so as to realize a comprehensive simulation verification of the hybrid loader.

[0111] Specifically, Figure 2-Figure 4 As shown in the figure, the hybrid loader model mainly includes three parts, namely, the loader vehicle multi-body model, the electric drive system model and the hydraulic system model. The loader vehicle multi-body model mainly includes the body structure, working device and tires, etc., which are mainly the overall support structure of the loader, bearing the weight and various forces of the whole machine, and having sufficient strength and stability; the electric drive system model includes generator, battery pack, drive motor, etc., and its main function is to drive the loader vehicle multi-body model to complete walking and other actions, and realize the movement and positioning of the loader vehicle multi-body model in the working area through effective electric energy conversion and transmission; the hydraulic system model includes three parts, the brake hydraulic system provides braking torque for the loader vehicle multi-body model, the working hydraulic system provides hydraulic pressure for the shoveling of the loader vehicle multi-body model, and the steering hydraulic system provides hydraulic pressure for the steering of the loader vehicle multi-body model.

[0112] The electric drive system of the loader includes a battery pack, an electric coupler, a resistor grid, an engine, a generator, a drive motor, etc. The components and tools of the Simscape toolbox in Matlab are used to model each module separately, and the physical parameters of each component are set, such as the voltage capacity of the battery pack and the rated power of the motor. Simulation debugging is performed and parameters are adjusted according to actual conditions to ensure that the behavior of each module meets expectations.

[0113] The hydraulic system of the loader includes brake hydraulic system, steering hydraulic system and working hydraulic system. The hydraulic system mainly includes pumps, valves, cylinders and other components. By setting the physical parameters of each component, a hydraulic system model is established.

[0114] The overall architecture of the hybrid loader modeling established by the hybrid loader modeling method mainly includes three parts, namely the hybrid loader, the loader control system and the command input module. The architecture is mainly based on the establishment of the loader vehicle model. The vehicle multi-body model is established based on the Simscape toolbox in Matlab and verified by the Simscape toolbox in Matlab. The complete vehicle model can provide a simulation platform for the design, development and verification of subsequent strategies, and can also support the analysis of the energy flow of the vehicle.

[0115] A modeling method for the coupling and information interaction of the mechanical-electrical-hydraulic model of a hybrid loader is proposed. The mechanical, electrical and hydraulic systems are the key parts of the complex system of the loader. Based on a unified platform, the Simscape toolbox in Matlab, these models of different physical domains can be coupled to analyze and verify the performance of the whole vehicle, while reducing development costs and time.

[0116] A magic tire modeling method for large loaders is proposed, and the interaction relationship between the wheels and the ground is established. In loader modeling, tire modeling is a key link because it directly affects the loader's driving stability, handling performance, and the accuracy of dynamic analysis. The magic tire model can simulate the actual state of the tire with high accuracy, and its mathematical expression is relatively simple, easy to understand and implement. The interaction relationship between the tire and the ground is usually represented by tire models, which can simulate the mechanical behavior of the tire under different working conditions, including longitudinal, lateral and vertical forces. An accurate tire model can better reflect the performance of the tire under actual working conditions, including traction, rolling resistance, lateral force, etc., thereby improving the accuracy of the overall loader simulation.

[0117] A method for modeling the asymmetric characteristics of motors based on the Simscape toolbox in Matlab is proposed. Since the motor system models provided by the Matlab toolbox are all symmetrical structures, that is, the motor driving characteristics and braking characteristics are consistent, which is inconsistent with the asymmetric characteristics of the actual motor. The driving and braking characteristic functions of the motor are established in a subsystem respectively. The subsystem input is the motor state, and the motor characteristic function is output according to whether the motor is in the driving state or the braking state. The asymmetric characteristic modeling of the motor can better reflect the performance of the motor in actual operation, which is helpful to design more accurate and reliable control strategies in the development of motor control systems.

[0118] An equivalent modeling method for the resistance grid of a loader is proposed. The resistance grid is an electronic component that is usually used in power systems as a current limiting and overvoltage protection device. In the modeling process of a hybrid loader, the resistance grid is an important component in the loader power system. The resistance grid modeling method based on the Simscape toolbox in Matlab can effectively simulate its protection function in the loader circuit. When the motor brakes when the battery is fully charged, the non-recoverable energy generated during the braking process can be consumed by the resistance grid, thereby effectively protecting the battery.

[0119] The simulation model established by the hybrid loader modeling method can be applied to the preliminary test verification of hybrid wheeled engineering machinery and agricultural machinery, such as hybrid loaders, hybrid tractors, hybrid mining trucks, etc.

[0120] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A modeling method for a hybrid loader, characterized in that: include: S10: According to the design parameters of the loader, a multi-body model of the loader, an electric drive system model and a hydraulic system model are established; S20: coupling the loader vehicle multi-body model, the electric drive system model and the hydraulic system model, and realizing information interaction among the three; S30: Establishing a loader control system to achieve precise control of the loader vehicle multi-body model, the electric drive system model and the hydraulic system model.

2. The modeling method of a hybrid loader according to claim 1, characterized in that: The establishment of the loader vehicle multi-body model specifically includes: A10: Based on the design parameters, a multi-body model of the loader is established by using a modeling software; A11: Transfer the loader vehicle multi-body model to the Simscape toolbox in Matlab; A12: Use the magic tire module and tire property file provided by the Simscape toolbox in Matlab to define the tire properties in the loader vehicle multi-body model; A13: According to different road conditions, a working road surface model in contact with the tire is established through the Infinite Plane module in the Simscape toolbox in Matlab.

3. The modeling method of a hybrid loader according to claim 2, characterized in that: Before executing A12, it also includes: A111: Use the Simscape toolbox in Matlab to verify whether the components of the loader vehicle multi-body model are set reasonably. If yes, execute A12; otherwise, execute A112; A112: Adjust the unreasonable components in the multi-body model of the loader vehicle and execute A11.

4. The modeling method of a hybrid loader according to claim 2, characterized in that: The establishment of the electric drive system model specifically includes: using the integrated module in the Simscape toolbox in Matlab, inputting the design parameters into the integrated module, so as to realize the modeling of the electric drive system model.

5. The modeling method of a hybrid loader according to claim 4, characterized in that: The establishment of the electric drive system model specifically also includes: using the engine module in the Simscape toolbox in Matlab to establish the speed regulation characteristics of the engine model in the electric drive system model.

6. The modeling method of a hybrid loader according to claim 4, characterized in that: The establishment of the electric drive system model specifically includes establishing a motor asymmetry model in the electric drive system model; Specifically include: B10: Establishing a motor driving function and a motor braking function according to the characteristic curve corresponding to the characteristic parameters of the motor; B20: introducing the motor drive function and the motor brake function into the Simscape toolbox in Matlab to form the motor asymmetry model; B30: If the motor asymmetry model receives a drive command, the motor drive function is called; if the motor asymmetry model receives a brake command, the motor brake function is called.

7. The modeling method of a hybrid loader according to claim 4, characterized in that: The establishment of the electric drive system model specifically includes: A resistor grid model is established by using an integrated module in the Simscape toolbox in Matlab to protect the battery model in the electric drive system model from overcharging; The diode model and the capacitor model are established by using the integrated module in the Simscape toolbox in Matlab. The diode model is used to ensure the direction of the current flowing into the resistor grid model, and the capacitor model is used to ensure the stability of the current flowing into the resistor grid model.

8. The modeling method of a hybrid loader according to claim 1, characterized in that: The establishment of the hydraulic system model specifically includes: C10: using the function module in the Simscape toolbox in Matlab, inputting the design parameters to model the brake hydraulic system, the steering hydraulic system and the working hydraulic system in the hydraulic system model; C20: Determine whether the brake hydraulic system, the steering hydraulic system and the working hydraulic system meet the set functional requirements. If yes, execute C30; if not, execute C40; C30: Determination of the hydraulic system model; C40: Adjust the systems in the brake hydraulic system, the steering hydraulic system and the working hydraulic system that do not meet the functional requirements and execute C20.

9. The modeling method of a hybrid loader according to claim 1, characterized in that: S20 specifically includes: S201: coupling the loader vehicle multi-body model, the electric drive system model and the hydraulic system model through the conversion multi-body interface in the Simscape toolbox in Matlab; S202: Using electrical signals, physical signals and simulation signals in the Simscape toolbox in Matlab, information interaction among the loader vehicle multi-body model, the electric drive system model and the hydraulic system model is realized.

10. The modeling method of a hybrid loader according to claim 1, characterized in that: Also includes S40: S401: Setting a command input module to simulate the driver controlling the loader to perform various actions; S402: Use the CAN bus in the Simscape toolbox in Matlab to communicate with the command input module and the loader control system.

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