A simulation method and device for transmission characteristics of an automotive powertrain

Abstract

The application discloses a simulation method and device for transmission characteristics of an automobile power system. According to the structure of the power system and the physical process of power system transmission, an initial transfer function of the power system torque and rotating speed is determined. A pulse torque is applied to the input end of the power system, the output shaft rotating speed change is obtained, the time domain response result of the system is determined, the parameters of the initial transfer function are determined, the transfer function is determined, and the power system transmission characteristic model is established. The torque demand of the power system to be measured is input into the power system transmission characteristic model, and the simulation result of the rotating speed change is obtained. The application can simulate and evaluate the performance of the vehicle power transmission system, and solves the problem that the prior art cannot simulate and evaluate the drivability in the early development stage.

Description

Technical Field

[0001] This application relates to the field of automotive drivability simulation analysis, specifically to a simulation method and apparatus for the transmission characteristics of an automotive powertrain system. Background Technology

[0002] During the vehicle development process, the final product's performance is determined by a combination of indicators such as power, economy, and drivability. Among these, drivability is related to the performance of the vehicle's power transmission system. However, because the performance of power transmission components varies between different vehicles, and conducting on-vehicle performance tests is extremely time-consuming and resource-intensive, the characteristic indicators of power transmission components are generally not considered in the early performance evaluation stages of product development, making it impossible to evaluate vehicle drivability in the early stages of development. Summary of the Invention

[0003] In view of this, this application provides a simulation method and apparatus for the transmission characteristics of an automotive power system. By establishing a power system transmission characteristic model, the power system transmission characteristics are determined, thus solving the problem that drivability cannot be simulated and evaluated in the early stages of development.

[0004] To address the above problems, the technical solutions provided in this application are as follows:

[0005] In a first aspect, this application provides a simulation method for the transmission characteristics of an automotive powertrain system, the method comprising:

[0006] Based on the structure of the power system and the physical process of power transmission, determine the initial transfer function of torque and speed of the power system;

[0007] A pulse torque is applied to the input end of the power system to obtain a change in the output shaft speed.

[0008] The system time-domain response result is determined based on the output shaft speed change.

[0009] Based on the system's time-domain response, determine the parameters of the initial transfer function;

[0010] Determine the transfer function based on the parameters of the initial transfer function;

[0011] Based on the transfer function, establish a model of the transmission characteristics of the dynamic system;

[0012] The torque requirement of the power system under test is input into the power system transmission characteristic model to obtain the simulation results of the speed change.

[0013] In one possible implementation, the method further includes:

[0014] After the vehicle power system travels a preset distance, the parameters of the transfer function are determined again, and the re-determined transfer function parameters are input into the power system transmission characteristic model.

[0015] In one possible implementation, the method further includes:

[0016] Obtain the original torque requirements of the power system under test;

[0017] Perform torque filtering on the original torque requirement;

[0018] Based on the torque filtering result, output the filtered torque requirement;

[0019] The filtered torque requirement is used as the torque requirement of the system under test.

[0020] In one possible implementation, the method further includes:

[0021] Based on the simulation results of the speed change, the system's jitter is determined;

[0022] If the speed fluctuation occurs when the torque changes from negative to positive, then adjust the torque rise slope of the torque filtering operation.

[0023] In one possible implementation, the method further includes: analyzing the consistency of simulation results based on the filtered torque demand during the life cycle of the power system under test;

[0024] If the consistency deviation of the simulation results is large, the parameters of the torque filter should be determined again.

[0025] Based on the re-determined torque filtering parameters, the original torque requirement is subjected to torque filtering operation again.

[0026] A second aspect of this application provides a simulation device for the transmission characteristics of an automotive powertrain system, the device comprising:

[0027] The model building unit is used to determine the initial transfer function of torque and speed of the power system based on the structure of the power system and the physical process of power transmission; apply a pulse torque to the input end of the power system to obtain the output shaft speed change; determine the system time-domain response result based on the output shaft speed change; determine the parameters of the initial transfer function based on the system time-domain response result; determine the transfer function based on the parameters of the initial transfer function; and establish a power system transmission characteristic model based on the transfer function.

[0028] The simulation unit is used to input the torque requirement of the power system under test into the power system transmission characteristic model to obtain the simulation results of the speed change.

[0029] A third aspect of this application provides an apparatus, the apparatus comprising: a processor and a memory;

[0030] The memory is used to store instructions;

[0031] The processor is configured to execute the instructions in the memory and perform the method described in the first aspect.

[0032] A fourth aspect of this application provides a computer-readable storage medium storing program code or instructions that, when run on a computer, cause the computer to perform the method described in the first aspect above.

[0033] Therefore, the embodiments of this application have the following beneficial effects: According to the method provided in this application, the power system transmission characteristics are tested, a power system transmission characteristic model is established, and the parameters are input into the power system transmission characteristic model for simulation analysis. This can simulate and evaluate the performance of the vehicle power transmission system, solving the problem that the prior art cannot simulate and evaluate drivability in the early stage of development. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A schematic diagram illustrating a simulation method for the transmission characteristics of an automotive powertrain system provided in an embodiment of this application;

[0036] Figure 2 Hysteresis characteristic diagram of tooth backlash provided in the embodiments of this application;

[0037] Figure 3 A logic block diagram for driving performance simulation provided in the embodiments of this application;

[0038] Figure 4 This is a schematic diagram of a simulation device for the transmission characteristics of an automotive powertrain system, provided as an embodiment of this application. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0040] The inventors discovered in their research that, due to the different performance of power transmission components in different vehicles, it is labor-intensive and resource-intensive to conduct actual vehicle performance tests. Therefore, the characteristic indicators of power transmission components are generally not considered in the performance evaluation in the early stages of product development, and the drivability of the vehicle cannot be evaluated in the early stages of development.

[0041] Based on this, this application provides a simulation method for the transmission characteristics of an automotive powertrain system. According to the structure of the powertrain system and the physical process of powertrain transmission, an initial transfer function for torque and speed is determined. A pulse torque is applied to the input end of the powertrain system to obtain the output shaft speed change, the system's time-domain response is determined, the parameters of the initial transfer function are determined, the transfer function is determined, and a powertrain transmission characteristic model is established. The torque requirement of the powertrain system under test is input into the powertrain transmission characteristic model to obtain the simulation results of the speed change. This application, by testing the powertrain transmission characteristics, establishing a powertrain transmission characteristic model, and inputting parameters into the powertrain transmission characteristic model for simulation analysis, can simulate and evaluate the performance of the vehicle's powertrain transmission system, solving the problem that existing technologies cannot simulate and evaluate drivability in the early stages of development.

[0042] To facilitate understanding of the methods provided in the embodiments of this application, the following description will be provided in conjunction with the accompanying drawings.

[0043] See Figure 1 This figure is a schematic diagram of a simulation method for the transmission characteristics of an automotive powertrain system provided in an embodiment of this application, as shown below. Figure 1 As shown, the method may include:

[0044] Step 101: Determine the initial transfer function of torque and speed of the power system based on the structure of the power system and the physical process of power transmission.

[0045] Step 102: Apply a pulse torque to the input end of the power system to obtain a change in the output shaft speed.

[0046] Step 103: Determine the system time-domain response result based on the output shaft speed change.

[0047] Step 104: Determine the parameters of the initial transfer function based on the system time-domain response results.

[0048] Step 105: Determine the transfer function based on the parameters of the initial transfer function;

[0049] Step 106: Based on the transfer function, establish a power system transmission characteristic model;

[0050] Step 107: Input the torque requirement of the power system under test into the power system transmission characteristic model to obtain the simulation results of the speed change.

[0051] The process of establishing the power system transmission characteristic model in the embodiments of this application is described in detail below:

[0052] In this embodiment, by analyzing the structural form of the powertrain, the order and characteristics of the powertrain's transmission characteristics are determined. For example, the powertrain system conserves energy during torque transmission; applying torque generates a rotational angle, and the change of this angle over time represents the rotational speed. Thus, the torque-speed transfer function of the powertrain is determined. Considering the backlash in the powertrain during actual operation, the backlash can be defined as a time-delay parameter in the transmission characteristics. The hysteresis characteristic diagram of the backlash is shown below. Figure 2 As shown.

[0053] The powertrain's transmission system satisfies the following physical processes:

[0054] Assuming the input shaft gear has a moment of inertia of J1, an input shaft torque of T1, and a rotation angle of θ1; the driven shaft gear has a load torque of T2, a rotation angle of θ2, a moment of inertia of J2, a damping coefficient of D2, and a stiffness of K2; and the speed ratio between the driving and driven gears is i, then the working process satisfies:

[0055]

[0056]

[0057] The backlash equation is described as follows:

[0058] T2=K2δ,δ=DZ(θ1-θ2)

[0059] DZ represents dead zone characteristics, which include:

[0060]

[0061] By applying a pulse torque T to the input of the power system, the change in the output shaft speed n is obtained, thereby determining the system's time-domain response. The results of the time-domain response are used to determine the relevant parameters in the transfer function, and the transfer equation is solved. This process is used to derive the transfer function and establish a power system transmission characteristic model.

[0062] The torque demand is input into the power system transmission characteristic model, and the output speed change is simulated.

[0063] In some possible implementations, the method further includes:

[0064] After the vehicle power system travels a preset distance, the parameters of the transfer function are determined again, and the re-determined transfer function parameters are input into the power system transmission characteristic model.

[0065] Specifically, the inherent characteristics of the power system will change during actual use. After the power system has traveled 5000km, a pulse torque T can be applied to the input end of the power system to redetermine the system's transfer function. The new transfer function parameters can then be input into the system's transfer characteristic model for optimization.

[0066] In some possible implementations, the method further includes:

[0067] Obtain the original torque requirements of the power system under test;

[0068] Perform torque filtering on the original torque requirement;

[0069] Based on the torque filtering result, output the filtered torque requirement;

[0070] The filtered torque requirement is used as the torque requirement of the system under test.

[0071] See Figure 3 The driving performance simulation logic block diagram provided in this embodiment of the application shows that, in this embodiment, the original torque demand of the power system under test can be obtained by inputting parameters such as vehicle speed and pedal depth into the demand torque analysis module; then, the original torque demand is input into the driving torque filtering module, which outputs the filtered torque demand; then, the filtered torque demand is used as the torque demand of the system under test and input into the power system transmission characteristic model to obtain the simulation results of speed change.

[0072] In some possible implementations, the method further includes:

[0073] Based on the simulation results of the speed change, the system's jitter is determined;

[0074] If the speed fluctuation occurs when the torque changes from negative to positive, then adjust the torque rise slope of the torque filtering operation.

[0075] Specifically, the system vibration is judged based on the simulated torque and the simulated speed of the power system transmission characteristic model. If the speed vibration occurs during the process of torque changing from negative to positive, it indicates that the vibration occurs during the tooth surface commutation stage of the power system. The simulation process is then optimized by adjusting the torque rise slope, the waiting time for torque to change from negative to positive, and the torque in the drivability filtering module, thereby achieving optimization of the simulated drivability.

[0076] In some possible implementations, the method further includes: analyzing the consistency of simulation results based on the filtered torque demand during the life cycle of the power system under test;

[0077] If the consistency deviation of the simulation results is large, the parameters of the torque filter should be determined again.

[0078] Based on the re-determined torque filtering parameters, the original torque requirement is subjected to torque filtering again.

[0079] Specifically, the current output torque demand can be obtained from the driving performance simulation process during the powertrain life cycle. If the simulation results are consistent, the torque rise slope used in the simulation can be input for real vehicle testing. If the consistency of the simulation results is significantly different, the simulation operation needs to be repeated, the driving performance filter-related parameters should be optimized, and the simulation should be repeated to achieve consistency of the simulation results.

[0080] Based on the above method embodiments, this application provides a simulation device for the transmission characteristics of an automotive powertrain system. (See attached image.) Figure 4 The figure is a schematic diagram of a simulation device for the transmission characteristics of an automotive powertrain system provided in an embodiment of this application. Figure 4 As shown, the device may include:

[0081] The model building unit 201 is used to determine the initial transfer function of torque and speed of the power system based on the structure of the power system and the physical process of power transmission; apply a pulse torque to the input end of the power system to obtain the output shaft speed change; determine the system time-domain response result based on the output shaft speed change; determine the parameters of the initial transfer function based on the system time-domain response result; determine the transfer function based on the parameters of the initial transfer function; and establish a power system transmission characteristic model based on the transfer function.

[0082] Simulation unit 202 is used to input the torque demand of the power system under test into the power system transmission characteristic model to obtain the simulation results of speed change.

[0083] It should be noted that the implementation of each unit in this embodiment can be found in the above method embodiment, and will not be repeated here.

[0084] In addition, this application embodiment also provides a device, the device including: a processor and a memory; the memory is used to store instructions; the processor is used to execute the instructions in the memory to execute the simulation method of the transmission characteristics of the automotive power system.

[0085] This application provides a computer-readable storage medium storing program code or instructions that, when run on a computer, cause the computer to execute the simulation method for the transmission characteristics of an automotive powertrain described above.

[0086] As can be seen, the method provided in the embodiments of this application, by testing the power system transmission characteristics, establishing a power system transmission characteristic model, and inputting parameters into the power system transmission characteristic model for simulation analysis, can simulate and evaluate the performance of the vehicle power transmission system, thus solving the problem that the prior art cannot simulate and evaluate drivability in the early stages of development.

[0087] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0088] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0089] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0090] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0091] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A simulation method for the transmission characteristics of an automotive powertrain system, characterized in that, The method includes: Based on the structure of the power system and the physical process of power transmission, determine the initial transfer function of torque and speed of the power system; A pulse torque is applied to the input end of the power system to obtain a change in the output shaft speed. The system time-domain response result is determined based on the output shaft speed change. Based on the system's time-domain response, determine the parameters of the initial transfer function; Determine the transfer function based on the parameters of the initial transfer function; Based on the transfer function, establish a model of the transmission characteristics of the dynamic system; The torque requirement of the power system under test is input into the power system transmission characteristic model to obtain the simulation results of the speed change.

2. The method according to claim 1, characterized in that, The method further includes: After the vehicle power system travels a preset distance, the parameters of the transfer function are determined again, and the re-determined transfer function parameters are input into the power system transmission characteristic model.

3. The method according to claim 1, characterized in that, The method further includes: Obtain the original torque requirements of the power system under test; Perform torque filtering on the original torque requirement; Based on the torque filtering result, output the filtered torque requirement; The filtered torque requirement is used as the torque requirement of the system under test.

4. The method according to claim 3, characterized in that, The method further includes: Based on the simulation results of the speed change, the system's jitter is determined; If the speed fluctuation occurs when the torque changes from negative to positive, then adjust the torque rise slope of the torque filtering operation.

5. The method according to claim 3, characterized in that, The method further includes: analyzing the consistency of simulation results based on the filtered torque demand during the life cycle of the power system under test; If the consistency deviation of the simulation results is large, the parameters of the torque filter should be determined again. Based on the re-determined torque filtering parameters, the original torque requirement is subjected to torque filtering operation again.

6. A simulation device for the transmission characteristics of an automotive powertrain system, characterized in that, The device includes: The model building unit is used to determine the initial transfer function of torque and speed of the power system based on the structure of the power system and the physical process of power transmission; apply a pulse torque to the input end of the power system to obtain the output shaft speed change; determine the system time-domain response result based on the output shaft speed change; determine the parameters of the initial transfer function based on the system time-domain response result; determine the transfer function based on the parameters of the initial transfer function; and establish a power system transmission characteristic model based on the transfer function. The simulation unit is used to input the torque requirement of the power system under test into the power system transmission characteristic model to obtain the simulation results of the speed change.

7. A device, characterized in that, The device includes: a processor and a memory; The memory is used to store instructions; The processor is configured to execute the instructions in the memory to perform the method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program code or instructions that, when executed on a computer, cause the computer to perform the method described in any one of claims 1-5.

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