Simulation method of torque capacity of dual-mass flywheel, control device, dual-mass flywheel

Abstract

The application provides a simulation method of a dual-mass flywheel torque capacity, a control device and a dual-mass flywheel. The simulation method of the dual-mass flywheel torque capacity comprises the following steps: a one-dimensional torsional vibration model of a gear shifting condition is established; based on the one-dimensional torsional vibration model, a driving torque of an engine applied to the dual-mass flywheel and a braking torque of an electric machine applied to the dual-mass flywheel are calculated to obtain an initial torque capacity of the dual-mass flywheel; based on the one-dimensional torsional vibration model, a gear shifting strategy is inputted to obtain a maximum transient torque of the dual-mass flywheel, and the initial torque capacity is evaluated according to the obtained maximum transient torque to obtain an approved torque capacity of the dual-mass flywheel. Based on the established one-dimensional torsional vibration model of the gear shifting condition, the approved torque capacity of the dual-mass flywheel is simulated and designed to avoid rectification of a product in a later period, shorten a product development cycle and reduce the development cost of the whole power system.

Description

Technical Field

[0001] This article relates to, but is not limited to, the field of vehicle technology, and in particular to a simulation method, control device, and dual-mass flywheel torque capacity. Background Technology

[0002] The torque capacity design of a traditional powertrain dual-mass flywheel is defined as the engine's rated torque multiplied by a corresponding safety factor. However, for hybrid vehicles, since the engine and electric motor need to work together on the dual-mass flywheel, the traditional method of defining the torque capacity of a powertrain flywheel is no longer applicable to the development of flywheels used in hybrid vehicles.

[0003] It should be noted that the above content falls within the inventor's technical knowledge and does not necessarily constitute prior art. Summary of the Invention

[0004] The purpose of this application is to provide a simulation method, control device, and dual-mass flywheel torque capacity simulation method. The simulation method allows for the design of the approved torque capacity of the dual-mass flywheel at the early stages of product development, based on a one-dimensional torsional vibration model of the shifting conditions. This avoids the need for later product modifications, shortens the product development cycle, and reduces the overall power system development cost.

[0005] The technical solution of this application embodiment is as follows:

[0006] A simulation method for the torque capacity of a dual-mass flywheel includes:

[0007] Construct a one-dimensional torsional vibration model of the gear shifting condition;

[0008] Based on the one-dimensional torsional vibration model, the driving torque applied by the engine to the dual-mass flywheel and the braking torque applied by the motor to the dual-mass flywheel are calculated to obtain the initial torque capacity of the dual-mass flywheel.

[0009] Based on the one-dimensional torsional vibration model, a shifting strategy is input to obtain the maximum transient torque of the dual-mass flywheel. The initial torque capacity is evaluated based on the obtained maximum transient torque to obtain the approved torque capacity of the dual-mass flywheel.

[0010] At the initial stage of dual-mass flywheel development, a one-dimensional torsional vibration model was built based on shifting conditions. Based on this model, the driving torque applied by the engine to the dual-mass flywheel and the braking torque applied by the motor were calculated. The maximum transient torque was obtained from the one-dimensional torsional vibration model using a shifting strategy. This maximum transient torque was then used to verify the initial torque capacity to obtain the approved torque capacity. This enabled the simulation analysis and calculation of the approved torque capacity of the dual-mass flywheel at the beginning of product development, effectively avoiding later product modifications, shortening the product development cycle, and reducing the overall power system development cost.

[0011] In some exemplary embodiments, the maximum torque of the engine is T E The driving torque is T1, T1 = T E *a1; The maximum torque of the motor is T P The braking torque is T2, T2 = T P *a2; The initial torque capacity is T, T=T1+T2;

[0012] Where a1 is the safety factor of engine torque and a2 is the safety factor of motor torque. Both a1 and a2 are calculated based on the simulation of the one-dimensional torsional vibration model.

[0013] The driving torque, braking torque, and initial torque capacity are obtained by simulation calculation based on a one-dimensional torsional vibration model, so as to improve the accuracy of obtaining the approved torque capacity of the dual-mass flywheel.

[0014] In some exemplary embodiments, the numerical range of a1 is 1.1 to 1.3.

[0015] In some exemplary embodiments, the value of a2 ranges from 1.0 to 1.2.

[0016] In some exemplary embodiments, the shifting strategy includes at least one of the following parameters: engine torque, shift point, motor torque, shift time, speed ratio before and after shifting, brake torque, or clutch torque.

[0017] The initial torque capacity is verified by using engine torque, shift point, motor torque, shift time, speed ratio before and after shift, brake torque or clutch torque, in order to improve the accuracy of obtaining the approved torque capacity.

[0018] In some exemplary embodiments, the step of inputting a shifting strategy based on the one-dimensional torsional vibration model to obtain the maximum transient torque of the dual-mass flywheel, and evaluating the initial torque capacity based on the obtained maximum transient torque to obtain the approved torque capacity of the dual-mass flywheel, includes:

[0019] If the obtained maximum transient torque is greater than the initial torque capacity, the shifting strategy is adjusted until the obtained maximum transient torque is not greater than the initial torque capacity, and then the initial torque capacity is set as the approved torque capacity.

[0020] Based on the one-dimensional torsional vibration model, when the maximum transient torque obtained is greater than the initial torque capacity, the shifting strategy is adjusted and the maximum transient torque is obtained again until the maximum transient torque obtained is not greater than the initial torque capacity. Then, the initial torque capacity is set as the approved torque capacity.

[0021] In some exemplary embodiments, the step of inputting a shifting strategy based on the one-dimensional torsional vibration model to obtain the maximum transient torque of the dual-mass flywheel, and evaluating the initial torque capacity based on the obtained maximum transient torque to obtain the approved torque capacity of the dual-mass flywheel, includes:

[0022] If the obtained maximum transient torque is greater than the initial torque capacity, the initial torque capacity is adjusted to obtain the approved torque capacity so that the approved torque capacity is not less than the maximum transient torque.

[0023] Based on the one-dimensional torsional vibration model, when the maximum transient torque obtained is greater than the initial torque capacity, the initial torque capacity is adjusted to obtain the approved torque capacity so that the approved torque capacity is not less than the maximum transient torque.

[0024] In some exemplary embodiments, the construction of the one-dimensional torsional vibration model for the shifting condition includes:

[0025] The main components of the engine are simplified, including one or more of torsional dampers, crankshafts, connecting rods, and pistons. The simplified main components are replaced by inertia, stiffness, and damping elements.

[0026] The main components of the engine are simplified to facilitate the construction of a one-dimensional torsional vibration model.

[0027] A control device includes a processor and a memory storing a computer program, the processor executing the computer program to implement the steps of the simulation analysis method described in any of the above embodiments.

[0028] A dual-mass flywheel, wherein the approved torque capacity of the dual-mass flywheel is obtained by simulation using the simulation analysis method described in any of the above embodiments.

[0029] After reading and understanding the accompanying diagrams and detailed descriptions, other aspects can be understood. Attached Figure Description

[0030] The accompanying drawings are provided to further understand the technical solutions in this paper and form part of the specification. They are used together with the embodiments of this application to explain the technical solutions in this paper and do not constitute a limitation on the technical solutions in this paper.

[0031] Figure 1 The flowchart shows the steps of the simulation method for the torque capacity of a dual-mass flywheel in some illustrative embodiments of this application.

[0032] Figure 2 This is a schematic diagram of a one-dimensional torsional vibration model in some illustrative embodiments of this application;

[0033] Figure 3 This application illustrates the dynamic torque variation of the dual-mass flywheel spring at different shift times in some illustrative embodiments.

[0034] Figure 4 The following are schematic diagrams showing engine speed changes at different shift times in some embodiments of this application.

[0035] Figure 5 This application illustrates the characteristics of the relative rotation angle change between the primary and secondary stages of a dual-mass flywheel at different shift times in some illustrative embodiments.

[0036] Figure 6 This application illustrates the characteristics of motor torque variation required by the transmission system under different shift times in some illustrative embodiments.

[0037] Figure label:

[0038] 1-Engine, 2-Dual-mass flywheel, 3-First motor, 4-Clutch, 5-Brake, 6-Gearbox, 7-Second motor, 8-Differential. Detailed Implementation

[0039] The technical solutions described herein will be further illustrated below with reference to the accompanying drawings and specific embodiments. It is understood that the specific embodiments described herein are merely for illustrative purposes and not for limiting the scope of this document.

[0040] The inventors of this application have discovered that during the development of hybrid vehicles, multiple instances of dual-mass flywheel spring breakage have occurred, leading to transmission system malfunction and rendering the hybrid vehicle unable to operate normally. Analysis of the vehicles experiencing this problem revealed that under certain operating conditions, the maximum transient torque of the transmission system exceeded the approved torque capacity of the dual-mass flywheel, causing the spring to break.

[0041] Therefore, the inventors of this application propose a simulation method for the torque capacity of a dual-mass flywheel. This simulation method can be used to simulate and verify the approved torque capacity of the dual-mass flywheel in the early stages of its development, which can effectively avoid problems such as breakage in later products, shorten the overall product development cycle, and reduce the overall power system development cost.

[0042] In one embodiment of this application, as Figure 1 As shown, a simulation method for the torque capacity of a dual-mass flywheel is provided. This simulation method for the torque capacity of a dual-mass flywheel includes:

[0043] A one-dimensional torsional vibration model of the gear shifting condition was constructed.

[0044] Based on a one-dimensional torsional vibration model, the driving torque applied by the engine to the dual-mass flywheel and the braking torque applied by the motor to the dual-mass flywheel are calculated to obtain the initial torque capacity of the dual-mass flywheel.

[0045] Based on a one-dimensional torsional vibration model, a shifting strategy is input to obtain the maximum transient torque of the dual-mass flywheel. The initial torque capacity is evaluated based on the obtained maximum transient torque to obtain the approved torque capacity of the dual-mass flywheel.

[0046] The simulation method for the torque capacity of a dual-mass flywheel provided in this application calculates the approved torque capacity requirement of the dual-mass flywheel based on the coordinated action of the engine and motor. During hybrid vehicle operation, due to the coordinated work of the motor and engine, especially during acceleration and upshifting, the motor assists the engine in reducing speed and torque. This causes the spring components inside the dual-mass flywheel to bear the combined effects of engine torque and motor torque. Therefore, a simulation method for the torque capacity of a dual-mass flywheel suitable for hybrid powertrain systems is established. Combined with a shift calibration strategy, the maximum transient torque of the transmission system is calculated to verify the initial torque capacity and obtain the approved torque capacity.

[0047] In some exemplary embodiments, such as Figure 1 , Figure 2 As shown, building a one-dimensional torsional vibration model for shifting conditions involves collecting structural parameters of the hybrid powertrain and geometric data of the transmission system. This includes, for example, two-dimensional drawings of the powertrain transmission system, a three-dimensional geometric model, a schematic diagram of the transmission system's cross-section, structural parameters of the engine and transmission, full-load excitation load of the engine, motor MAP (Motor Mapping Map), clutch characteristics, and calibration strategies. The motor MAP, also known as a contour map or cloud map, is a data curve generated during motor testing, primarily reflecting the distribution of motor efficiency at different speeds and torques.

[0048] When developing a vehicle model, the main components of the powertrain can utilize data from existing models. Alternatively, based on existing data, local structures can be optimized to obtain data that meets development parameters. Another approach is to create entirely new models for key components. Since vehicle transmission systems are typically time-varying systems, the simulation model can be simplified step-by-step according to acceleration and upshifting conditions. For example, components such as the engine's torsional damper, crankshaft, connecting rods, pistons, and dual-mass flywheel can be replaced with inertia, stiffness, and damping elements. Alternatively, the dual-mass flywheel can be modeled using existing 3D data of the dual-mass flywheel to be used. Building a one-dimensional torsional vibration model for shifting conditions also includes simplifying each shaft segment of the transmission to the inertia, stiffness, and damping of each shaft segment in each gear. Figure 2 As shown, taking a certain car model as an example, the one-dimensional torsional vibration model is simplified to include an engine 1, a dual-mass flywheel 2, a first motor 3, a clutch 4, a brake 5, a gearbox 6, a second motor 7, and a differential 8, etc.

[0049] In some exemplary embodiments, based on the constructed one-dimensional torsional vibration model, the driving torque applied by the engine to the dual-mass flywheel is calculated and denoted as T1. Where T1 = T E *a1. T E denoted as the engine's maximum torque. a1 is the safety factor for the engine torque. a1 is calculated based on a one-dimensional torsional vibration model simulation.

[0050] Based on the established one-dimensional torsional vibration model, the braking torque applied by the motor to the dual-mass flywheel was calculated and denoted as T2. Where T2 = T P *a2. T P denoted as , where is the maximum torque of the motor. 'a2' is the safety factor for the motor torque. 'a2' is calculated based on a one-dimensional torsional vibration model simulation. The calculation method and steps for 'a2' can be found in the calculation of 'a1'. The initial torque capacity of the dual-mass flywheel is T, where T = T1 + T2.

[0051] In some exemplary embodiments, the value of a1 ranges from 1.1 to 1.3. The value of a2 ranges from 1.0 to 1.2.

[0052] In some exemplary embodiments, such as Figure 1 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, based on a one-dimensional torsional vibration model, a shifting strategy is input to obtain the maximum transient torque of the dual-mass flywheel. For example, as... Figure 3 As shown, the dynamic torque variation curves of the dual-mass flywheel are presented under two different shift times (t1, t2). Figure 3As shown, the maximum dynamic torque values ​​of the dual-mass flywheel are TM1 and TM2 under two different shift times. The shift strategy includes one or more of the following: engine torque, shift point, motor torque, shift time, gear ratio before and after the shift, brake torque, and clutch torque. The initial torque capacity is evaluated based on the obtained maximum transient torque. For example, as... Figure 4 As shown, the engine speed change history is presented under two different shift times (t1, t2). Figure 4 As shown, the engine speed changes are N1 and N2 for the two shift times, respectively. For example, as... Figure 5 As shown, the relative rotation angles of the primary and secondary stages of the dual-mass flywheel are given for two different shift times (t1, t2). Figure 5 As shown, the changes in the relative rotation angles of the primary and secondary components of the dual-mass flywheel are α1 and α2 at the two shift times, respectively. The engine speed and the relative rotation angles of the primary and secondary components of the dual-mass flywheel at different shift times can also be used to assist in assessing the initial torque capacity. For example, at two different shift times, the relative rotation angles of the primary and secondary components of the dual-mass flywheel can be used to effectively avoid the risk of spring coiling. Figure 6 As shown, the characteristics of the motor torque variation required by the entire transmission system under two different shift times (t1, t2) are presented. Figure 6 As shown, the changes in motor torque at the two shift times are TD1 and TD2, respectively.

[0053] If the obtained maximum transient torque is not greater than the initial torque capacity, the initial torque capacity can be set as the approved torque capacity. Alternatively, the approved torque capacity can be defined as a value between the maximum transient torque and the initial torque capacity. If the obtained maximum transient torque is greater than the initial torque capacity, adjustment is required. For example, after adjusting the shift strategy, the maximum transient torque is obtained again, and this process is repeated until the obtained maximum transient torque is not greater than the initial torque capacity, at which point the initial torque capacity is set as the approved torque capacity. Adjusting the shift strategy involves adjusting at least one parameter of engine torque, shift point, motor torque, shift time, gear ratio before and after shift, brake torque, or clutch torque. Alternatively, the initial torque capacity is adjusted to obtain the approved torque capacity, ensuring that the approved torque capacity is not less than the maximum transient torque. Since the initial torque capacity is T, T = T E *a1+T P *a2, can be adjusted by T E a1, T P At least one parameter in a2 is used to adjust the initial torque capacity.

[0054] Another embodiment of this application provides a control device. The controller includes a processor and a memory storing a computer program. The processor is configured to execute the computer program to implement the steps of the simulation analysis method described in any of the above embodiments.

[0055] Another embodiment of this application proposes a dual-mass flywheel. The approved torque capacity of the dual-mass flywheel is obtained by simulation using the simulation analysis method described in any embodiment.

[0056] In the description herein, the terms “upper,” “lower,” “one side,” “the other side,” “one end,” “the other end,” “side,” “opposite,” “four corners,” “periphery,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the structure referred to has a specific orientation, or is constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this document.

[0057] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the terms "connection," "direct connection," "indirect connection," "fixed connection," "installation," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. The terms "installation," "connection," and "fixed connection" can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this document based on the specific circumstances.

[0058] While the embodiments disclosed herein are as described above, the content is merely for the purpose of understanding this document and is not intended to limit it. Any person skilled in the art may make any modifications and changes to the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection herein shall still be defined by the appended claims.

Claims

1. A simulation method for the torque capacity of a dual-mass flywheel, characterized in that, include: Construct a one-dimensional torsional vibration model of the gear shifting condition; Based on the one-dimensional torsional vibration model, the driving torque applied by the engine to the dual-mass flywheel and the braking torque applied by the motor to the dual-mass flywheel are calculated to obtain the initial torque capacity of the dual-mass flywheel. Based on the one-dimensional torsional vibration model, a shifting strategy is input to obtain the maximum transient torque of the dual-mass flywheel. The initial torque capacity is evaluated based on the obtained maximum transient torque to obtain the approved torque capacity of the dual-mass flywheel. The shifting strategy includes at least one of the following parameters: engine torque, shift point, motor torque, shift time, speed ratio before and after shift, brake torque, or clutch torque. The maximum torque of the engine is T. E The driving torque is T1, T1=T E a1; The maximum torque of the motor is T P The braking torque is T2, T2=T P a2; The initial torque capacity is T, T = T1 + T2; where a1 is the safety factor of the engine torque, a2 is the safety factor of the motor torque, and both a1 and a2 are calculated based on the simulation of the one-dimensional torsional vibration model; the value range of a1 is 1.1 to 1.3, and the value range of a2 is 1.0 to 1.2; Based on the one-dimensional torsional vibration model, a shifting strategy is input to obtain the maximum transient torque of the dual-mass flywheel. The initial torque capacity is then evaluated based on the obtained maximum transient torque to obtain the approved torque capacity of the dual-mass flywheel, including: If the obtained maximum transient torque is greater than the initial torque capacity, the shifting strategy is adjusted until the obtained maximum transient torque is not greater than the initial torque capacity, and then the initial torque capacity is set as the approved torque capacity; or, if the obtained maximum transient torque is greater than the initial torque capacity, the initial torque capacity is adjusted to obtain the approved torque capacity so that the approved torque capacity is not less than the maximum transient torque.

2. The simulation method for the torque capacity of a dual-mass flywheel as described in claim 1, characterized in that, The one-dimensional torsional vibration model for the shifting condition includes: The main components of the engine are simplified, including one or more of torsional dampers, crankshafts, connecting rods, and pistons. The simplified main components are replaced by inertia, stiffness, and damping elements.

3. A control device, characterized in that, It includes a processor and a memory storing a computer program, the processor executing the computer program to implement the steps of a simulation method for the torque capacity of a dual-mass flywheel as described in any one of claims 1 to 2.

4. A dual-mass flywheel, characterized in that, The approved torque capacity of the dual-mass flywheel is obtained by simulation using a simulation method for the torque capacity of a dual-mass flywheel as described in any one of claims 1 to 2.

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