A starting noise control method and system for a hybrid vehicle and a hybrid vehicle

Abstract

The application discloses a hybrid vehicle starting noise control method and system and a hybrid vehicle, and relates to the technical field of vehicles.The method comprises the following steps: collecting relevant structural parameters of a hybrid engine, establishing a hybrid engine thermodynamic simulation model, and calibrating; adjusting different initial phase angles of a crankshaft as input boundaries, calculating engine cylinder pressure curves and torque fluctuation data; collecting parameter information of the hybrid engine, a dual-mass flywheel and a multi-in-one transmission, constructing a hybrid assembly dynamics model, performing transient dynamics analysis calibration, and obtaining a hybrid assembly transient dynamics model; adjusting the initial phase angle of the crankshaft, calculating engine output torque fluctuation and transmission joint surface vibration amplitude, and obtaining an optimal initial phase angle; and when the hybrid engine is turned off, calibrating control of the crankshaft stopping at the optimal initial phase angle.The application can solve the technical problem that the hybrid engine has abnormal sound during starting in the prior art.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically to a method, system, and hybrid vehicle for controlling startup noise. Background Technology

[0002] The development of seamless NVH (Noise, Vibration, and Harshness) intervention technology for hybrid powertrain engines is a key technology for improving the overall quality of hybrid vehicles and a technological barrier for differentiated competition in the hybrid vehicle market. Its core lies in achieving seamless switching between the hybrid engine and electric motor through optimization of the electronic control system, coordinated control of the power source, and NVH management. This transforms complex technical logic into a "seamless experience" that is perceptible to the user, improving driving smoothness, quietness, and comfort.

[0003] Due to the high efficiency requirements of hybrid engines, the compression ratio of the engine is relatively large. During the start-up process of the engine driven by the electric motor, the engine cylinder pressure is high and the torque fluctuates greatly. The transient impact of the powertrain output shaft causes the gear pair meshing in the transmission system to produce double-sided impact, resulting in vibration and abnormal noise. At the same time, the coupling between the rigid body modes of the powertrain (such as pitch mode and torsional mode) and the excitation frequency of the system also generates structural noise. This leads to abnormal noise when the hybrid engine starts. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method, system and hybrid vehicle for controlling the starting noise of a hybrid vehicle, in order to solve the technical problem of abnormal noise in hybrid engines during startup in the prior art.

[0005] A first aspect of the present invention is to provide a method for controlling the start-up noise of a hybrid electric vehicle, the method comprising:

[0006] Collect relevant structural parameters of the hybrid engine, establish a thermodynamic simulation model of the hybrid engine, test various performance parameters of the hybrid engine under preset operating conditions, and calibrate the thermodynamic simulation model of the hybrid engine.

[0007] Based on the thermodynamic simulation model of the hybrid engine, different initial phase angles of the crankshaft are adjusted as input boundaries to calculate the engine cylinder pressure curve and torque fluctuation data during the start-up process of the hybrid engine.

[0008] Collect parameter information of hybrid engine, dual-mass flywheel and multi-in-one transmission, construct hybrid powertrain dynamic model, use the engine cylinder pressure curve as input boundary, perform transient dynamic analysis and calibration on the hybrid powertrain dynamic model to obtain the hybrid powertrain transient dynamic model;

[0009] The initial phase angle of the crankshaft is gradually adjusted, and the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface are calculated based on the thermodynamic simulation model of the hybrid engine and the transient dynamic model of the hybrid powertrain.

[0010] Based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface, the optimal initial phase angle is obtained. When the hybrid engine is turned off, the crankshaft is calibrated to stop at the optimal initial phase angle to reduce starting noise.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: The starting noise control method for hybrid electric vehicles provided by the present invention analyzes the cylinder pressure during the start-up of the hybrid engine based on the thermodynamic simulation model of the hybrid engine, and combines the transient dynamic model simulation of the hybrid assembly. It proposes the influence law of different crankshaft initial positions on cylinder pressure fluctuations and hybrid assembly surface vibration amplitude during the start-up process, accurately determines the initial phase angle of the crankshaft during the start-up of the hybrid engine, and uses the motor control unit and hybrid vehicle controller calibration methods to achieve closed-loop control during engine shutdown, so that the crankshaft stops at the optimal initial phase angle, reducing the noise of the next start-up, thereby solving the technical problem of abnormal noise phenomenon of hybrid engines during start-up in the prior art.

[0012] According to one aspect of the above technical solution, the steps of collecting relevant structural parameters of the hybrid engine, establishing a thermodynamic simulation model of the hybrid engine, testing various performance characteristics of the hybrid engine under preset operating conditions, and calibrating the thermodynamic simulation model of the hybrid engine specifically include:

[0013] Collect relevant structural parameters of the hybrid engine, including cylinder bore, stroke, connecting rod length, compression ratio, valve timing, and intake and exhaust port dimensions. Establish a thermodynamic simulation model of the hybrid engine using a one-dimensional thermodynamic model.

[0014] Under preset operating conditions, the various performance characteristics of the hybrid engine were tested, and the thermodynamic simulation model of the hybrid engine was calibrated.

[0015] According to one aspect of the above technical solution, and under preset operating conditions, the steps of testing various performance characteristics of the hybrid engine and calibrating the thermodynamic simulation model of the hybrid engine specifically include:

[0016] Under preset operating conditions, including reverse drag steady-state operating conditions and idle combustion steady-state operating conditions, the cylinder pressure of the hybrid engine is tested and compared with the thermodynamic simulation model of the hybrid engine to determine whether the calibration comparison results are consistent.

[0017] If so, proceed to the next step;

[0018] If not, adjust the relevant parameters of the hybrid engine thermodynamic simulation model until the calibration comparison results are consistent. The relevant boundary parameters include intake pressure, temperature, exhaust back pressure, combustion model parameters, and heat transfer coefficient.

[0019] According to one aspect of the above technical solution, the steps of collecting parameter information of the hybrid engine, dual-mass flywheel, and multi-in-one transmission, constructing a hybrid powertrain dynamics model, and performing transient dynamics analysis and calibration on the hybrid powertrain dynamics model using the engine cylinder pressure curve as the input boundary to obtain the transient dynamics model of the hybrid powertrain specifically include:

[0020] Collect parameter information of the hybrid engine, dual-mass flywheel and multi-in-one transmission. The parameter information includes engine structural parameters, gear structural parameters, multi-in-one transmission structural parameters, system mass, inertia, stiffness and damping, and construct a dynamic model of the hybrid powertrain.

[0021] Using the engine cylinder pressure curve as the input boundary, the hybrid powertrain dynamics model is calibrated by transient dynamics analysis to obtain the hybrid powertrain transient dynamics model.

[0022] According to one aspect of the above technical solution, the step of performing transient dynamic analysis and calibration on the hybrid powertrain dynamic model using the engine cylinder pressure curve as the input boundary to obtain the transient dynamic model of the hybrid powertrain specifically includes:

[0023] Using the engine cylinder pressure curve as the input boundary, transient dynamic analysis is performed on the hybrid powertrain dynamic model to calculate engine output torque fluctuation, powertrain mount active end vibration, powertrain surface structure vibration, gear and spline impact force, and calibrate and compare it with the actual test data to determine whether the calibration comparison structure is consistent.

[0024] If so, then the transient dynamics model of the hybrid powertrain is obtained;

[0025] If not, adjust the parameter information until the calibration comparison results are consistent.

[0026] According to one aspect of the above technical solution, the steps of gradually adjusting the initial phase angle of the crankshaft, and calculating the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface based on the hybrid engine thermodynamic simulation model and the hybrid powertrain transient dynamic model, specifically include:

[0027] Starting from an initial phase angle of 0° on the crankshaft, and using a preset progressive angle, the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface are calculated based on the hybrid engine thermodynamic simulation model and the hybrid powertrain transient dynamic model. The preset progressive angle is 8° to 12°.

[0028] According to one aspect of the above technical solution, based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface, the optimal initial phase angle is obtained. When the hybrid engine is shut off, the crankshaft is calibrated to stop at the optimal initial phase angle to reduce starting noise. This step specifically includes:

[0029] The optimal initial phase angle is determined based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface.

[0030] When the hybrid engine is turned off, the engine management system obtains the real-time position of the crankshaft through the crankshaft position sensor and sends it to the hybrid vehicle controller.

[0031] The hybrid vehicle controller obtains the target position of the crankshaft based on the optimal initial phase angle and the real-time position of the crankshaft, adjusts the motor torque, and performs closed-loop control of the crankshaft angle. When the target position is approached, the torque is adjusted to zero to control the crankshaft stop position and reduce noise during the next start-up.

[0032] According to one aspect of the above technical solution, the method further includes:

[0033] Starting from an initial crankshaft phase angle of 0°, and using progressive angles of 8° to 12°, we tested real engine output torque fluctuations, real transmission engagement surface vibration amplitudes, and near-field noise on a hybrid vehicle.

[0034] The optimal region for the initial phase angle is obtained based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface.

[0035] Based on the actual engine output torque fluctuation, the actual vibration amplitude of the gearbox mating surface, and the near-field noise, the optimal region is fine-tuned to obtain the optimal initial phase angle and determine the parameters used for calibration control.

[0036] A second aspect of the present invention provides a start-up noise control system for a hybrid electric vehicle, the start-up noise control system being used to implement the above-described start-up noise control method for a hybrid electric vehicle, the system comprising:

[0037] The thermodynamic model construction module is used to collect relevant structural parameters of the hybrid engine, establish a thermodynamic simulation model of the hybrid engine, test various performance characteristics of the hybrid engine under preset operating conditions, and calibrate the thermodynamic simulation model of the hybrid engine.

[0038] The thermodynamic model calibration module is used to calculate the engine cylinder pressure curve and torque fluctuation data of the hybrid engine during the start-up process by adjusting different initial phase angles of the crankshaft as input boundaries based on the thermodynamic simulation model of the hybrid engine.

[0039] The dynamic model construction module is used to collect parameter information of the hybrid engine, dual-mass flywheel and multi-in-one transmission, construct the hybrid powertrain dynamic model, and perform transient dynamic analysis and calibration on the hybrid powertrain dynamic model with the engine cylinder pressure curve as the input boundary to obtain the hybrid powertrain transient dynamic model.

[0040] The vibration calculation module is used to gradually adjust the initial phase angle of the crankshaft, and calculate the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface based on the thermodynamic simulation model of the hybrid engine and the transient dynamic model of the hybrid powertrain.

[0041] The phase adjustment module is used to determine the optimal initial phase angle based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface. When the hybrid engine is turned off, it calibrates and controls the crankshaft to stop at the optimal initial phase angle, reducing starting noise.

[0042] A third aspect of the present invention is to provide a hybrid electric vehicle, the hybrid electric vehicle including the aforementioned start-up noise control system for the hybrid electric vehicle. Attached Figure Description

[0043] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0044] Figure 1 This is a flowchart illustrating the starting noise control method for a hybrid electric vehicle according to Embodiment 1 of the present invention.

[0045] Figure 2 This is a structural block diagram of the start-up noise control system for a hybrid electric vehicle in Embodiment 2 of the present invention;

[0046] Component symbol explanation in the attached diagram:

[0047] Thermodynamic model construction module 100, thermodynamic model calibration module 200, kinetic model construction module 300, vibration calculation module 400, phase adjustment module 500;

[0048] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0049] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0050] Example 1

[0051] Please see Figure 1 The first embodiment of the present invention provides a method for controlling the start-up noise of a hybrid electric vehicle, the method comprising steps S10-S14:

[0052] Step S10: Collect relevant structural parameters of the hybrid engine, establish a thermodynamic simulation model of the hybrid engine, test various performance parameters of the hybrid engine under preset operating conditions, and calibrate the thermodynamic simulation model of the hybrid engine.

[0053] Specifically, relevant structural parameters of the hybrid engine are collected, including cylinder bore, stroke, connecting rod length, compression ratio, valve timing, and intake and exhaust port dimensions. A thermodynamic simulation model of the hybrid engine is established using a one-dimensional thermodynamic model.

[0054] Under preset operating conditions, including reverse drag steady-state operating conditions and idle combustion steady-state operating conditions, the cylinder pressure of the hybrid engine is tested and compared with the thermodynamic simulation model of the hybrid engine to determine whether the calibration comparison results are consistent.

[0055] If so, proceed to the next step;

[0056] If not, adjust the relevant parameters of the hybrid engine thermodynamic simulation model until the calibration comparison results are consistent. The relevant boundary parameters include intake pressure, temperature, exhaust back pressure, combustion model parameters, and heat transfer coefficient.

[0057] Step S11: Based on the thermodynamic simulation model of the hybrid engine, adjust the different initial phase angles of the crankshaft as input boundaries, and calculate the engine cylinder pressure curve and torque fluctuation data of the hybrid engine during the start-up process;

[0058] Step S12: Collect parameter information of hybrid engine, dual-mass flywheel and multi-in-one transmission, construct hybrid powertrain dynamic model, use the engine cylinder pressure curve as input boundary, perform transient dynamic analysis and calibration on the hybrid powertrain dynamic model to obtain the hybrid powertrain transient dynamic model;

[0059] Specifically, the process involves collecting parameter information on the hybrid engine, dual-mass flywheel, and multi-in-one transmission. The parameter information includes engine structural parameters, gear structural parameters, multi-in-one transmission structural parameters, system mass, inertia, stiffness, and damping, and constructing a dynamic model of the hybrid powertrain.

[0060] Using the engine cylinder pressure curve as the input boundary, transient dynamic analysis is performed on the hybrid powertrain dynamic model to calculate engine output torque fluctuation, powertrain mount active end vibration, powertrain surface structure vibration, gear and spline impact force, and calibrate and compare it with the actual test data to determine whether the calibration comparison structure is consistent.

[0061] If so, then the transient dynamics model of the hybrid powertrain is obtained;

[0062] If not, adjust the parameter information until the calibration comparison results are consistent.

[0063] Step S13: Gradually adjust the initial phase angle of the crankshaft, and calculate the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface based on the hybrid engine thermodynamic simulation model and the hybrid powertrain transient dynamic model.

[0064] Specifically, starting from the initial phase angle of the crankshaft at 0°, a preset progressive angle is used to calculate the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface based on the hybrid engine thermodynamic simulation model and the hybrid powertrain transient dynamic model. The preset progressive angle is 8° to 12°.

[0065] Step S14: Based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface, the optimal initial phase angle is obtained. When the hybrid engine is turned off, the control crankshaft is calibrated to stop at the optimal initial phase angle to reduce starting noise.

[0066] The optimal initial phase angle is determined based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface.

[0067] When the hybrid engine is turned off, the engine management system obtains the real-time position of the crankshaft through the crankshaft position sensor and sends it to the hybrid vehicle controller.

[0068] The hybrid vehicle controller obtains the target position of the crankshaft based on the optimal initial phase angle and the real-time position of the crankshaft, adjusts the motor torque, and performs closed-loop control of the crankshaft angle. When the target position is approached, the torque is adjusted to zero to control the crankshaft stop position and reduce noise during the next start-up.

[0069] Among them, the hybrid vehicle controller adjusts the motor torque and performs closed-loop control of the crankshaft angle. When it is close to the target position, the torque is adjusted to zero, thereby precisely controlling the stopping position of the crankshaft and preparing it to be in the optimal phase for the next start, which can reduce problems such as starting vibration.

[0070] The method further includes:

[0071] Starting from an initial crankshaft phase angle of 0°, and using progressive angles of 8° to 12°, we tested real engine output torque fluctuations, real transmission engagement surface vibration amplitudes, and near-field noise on a hybrid vehicle.

[0072] The optimal region for the initial phase angle is obtained based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface.

[0073] Based on actual engine output torque fluctuations, actual transmission mating surface vibration amplitudes, and near-field noise, the optimal region is fine-tuned to obtain the optimal initial phase angle, thus determining the parameters used for calibration control. This ensures that the engine's vibration, noise, and other performance characteristics are optimal during actual operation.

[0074] It should be noted that, through cylinder pressure analysis during hybrid engine startup and simulation using a transient dynamics model of the hybrid powertrain, the influence of different initial crankshaft positions on cylinder pressure fluctuations and the amplitude of surface vibrations in the hybrid powertrain during startup was proposed, accurately determining the initial crankshaft position during hybrid engine startup. Furthermore, closed-loop control was implemented during engine shutdown using calibration methods for the motor control unit and the hybrid vehicle controller, ensuring the crankshaft position of the hybrid engine remained fixed at the optimal position. This method is universally applicable and does not increase costs.

[0075] Compared with existing technologies, the hybrid vehicle startup noise control method shown in this embodiment analyzes the cylinder pressure during hybrid engine startup based on a hybrid engine thermodynamic simulation model and combines it with a hybrid powertrain transient dynamics model simulation. It proposes the influence of different crankshaft initial positions on cylinder pressure fluctuations and hybrid powertrain surface vibration amplitudes during hybrid engine startup, accurately determining the initial phase angle of the crankshaft during startup. Through calibration of the motor control unit and hybrid vehicle controller, closed-loop control is implemented during engine shutdown to keep the crankshaft at the optimal initial phase angle, reducing noise during the next startup. This solves the technical problem of abnormal noise during hybrid engine startup in existing technologies.

[0076] Example 2

[0077] Please see Figure 2 The image shows a second embodiment of a hybrid electric vehicle starting noise control system, the system comprising:

[0078] The thermodynamic model construction module 100 is used to collect relevant structural parameters of the hybrid engine, establish a thermodynamic simulation model of the hybrid engine, test various performance characteristics of the hybrid engine under preset operating conditions, and calibrate the thermodynamic simulation model of the hybrid engine.

[0079] The thermodynamic model calibration module 200 is used to calculate the engine cylinder pressure curve and torque fluctuation data of the hybrid engine during the start-up process by adjusting different initial phase angles of the crankshaft as input boundaries based on the thermodynamic simulation model of the hybrid engine.

[0080] The dynamic model construction module 300 is used to collect parameter information of the hybrid engine, dual-mass flywheel and multi-in-one transmission, construct a hybrid powertrain dynamic model, and perform transient dynamic analysis and calibration on the hybrid powertrain dynamic model with the engine cylinder pressure curve as the input boundary to obtain the hybrid powertrain transient dynamic model.

[0081] The vibration calculation module 400 is used to gradually adjust the initial phase angle of the crankshaft and calculate the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface based on the thermodynamic simulation model of the hybrid engine and the transient dynamic model of the hybrid powertrain.

[0082] The phase adjustment module 500 is used to determine the optimal initial phase angle based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface. When the hybrid engine is turned off, it calibrates and controls the crankshaft to stop at the optimal initial phase angle, thereby reducing starting noise.

[0083] Compared with existing technologies, the hybrid vehicle start-up noise control system shown in this embodiment analyzes the cylinder pressure during hybrid engine start-up based on the thermodynamic model construction and calibration module, and combines the transient dynamic model simulation of the hybrid powertrain in the dynamic model construction module. It proposes the influence law of cylinder pressure fluctuation and hybrid powertrain surface vibration amplitude based on different crankshaft initial positions during hybrid engine start-up, accurately determines the initial phase angle of the crankshaft during hybrid engine start-up, and uses the motor control unit of the phase adjustment module and the hybrid vehicle controller calibration method to achieve closed-loop control during engine shutdown, so that the crankshaft stops at the optimal initial phase angle, reducing noise during the next start-up.

[0084] Example 3

[0085] A third embodiment of the present invention provides a hybrid electric vehicle, the hybrid electric vehicle including the start-up noise control system of the hybrid electric vehicle of the above embodiments.

[0086] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0088] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method of controlling a startup noise of a hybrid vehicle, characterized by, The method includes: Collect relevant structural parameters of the hybrid engine, establish a thermodynamic simulation model of the hybrid engine, test various performance parameters of the hybrid engine under preset operating conditions, and calibrate the thermodynamic simulation model of the hybrid engine. Based on the thermodynamic simulation model of the hybrid engine, different initial phase angles of the crankshaft are adjusted as input boundaries to calculate the engine cylinder pressure curve and torque fluctuation data during the start-up process of the hybrid engine. Collect parameter information of hybrid engine, dual-mass flywheel and multi-in-one transmission, construct hybrid powertrain dynamic model, use the engine cylinder pressure curve as input boundary, perform transient dynamic analysis and calibration on the hybrid powertrain dynamic model to obtain the hybrid powertrain transient dynamic model; The initial phase angle of the crankshaft is gradually adjusted, and the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface are calculated based on the thermodynamic simulation model of the hybrid engine and the transient dynamic model of the hybrid powertrain. Based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface, the optimal initial phase angle is obtained. When the hybrid engine is turned off, the crankshaft is calibrated to stop at the optimal initial phase angle to reduce starting noise.

2. The starting noise control method of a hybrid vehicle according to claim 1, characterized by, The steps of collecting relevant structural parameters of the hybrid engine, establishing a thermodynamic simulation model of the hybrid engine, testing various performance characteristics of the hybrid engine under preset operating conditions, and calibrating the thermodynamic simulation model of the hybrid engine specifically include: Collect relevant structural parameters of the hybrid engine, including cylinder bore, stroke, connecting rod length, compression ratio, valve timing, and intake and exhaust port dimensions. Establish a thermodynamic simulation model of the hybrid engine using a one-dimensional thermodynamic model. Under preset operating conditions, the various performance characteristics of the hybrid engine were tested, and the thermodynamic simulation model of the hybrid engine was calibrated.

3. The starting noise control method of a hybrid vehicle according to claim 2, characterized by, The steps include testing various performance characteristics of the hybrid engine under preset operating conditions and calibrating the thermodynamic simulation model of the hybrid engine, specifically including: Under preset operating conditions, including reverse drag steady-state operating conditions and idle combustion steady-state operating conditions, the cylinder pressure of the hybrid engine is tested and compared with the thermodynamic simulation model of the hybrid engine to determine whether the calibration comparison results are consistent. If so, proceed to the next step; If not, adjust the relevant parameters of the hybrid engine thermodynamic simulation model until the calibration comparison results are consistent. The relevant boundary parameters include intake pressure, temperature, exhaust back pressure, combustion model parameters, and heat transfer coefficient.

4. The starting noise control method of a hybrid vehicle according to claim 1, characterized by, The steps of collecting parameter information of the hybrid engine, dual-mass flywheel, and multi-in-one transmission, constructing a hybrid powertrain dynamics model, and performing transient dynamics analysis and calibration on the hybrid powertrain dynamics model using the engine cylinder pressure curve as the input boundary to obtain the transient dynamics model of the hybrid powertrain specifically include: Collect parameter information of the hybrid engine, dual-mass flywheel and multi-in-one transmission. The parameter information includes engine structural parameters, gear structural parameters, multi-in-one transmission structural parameters, system mass, inertia, stiffness and damping, and construct a dynamic model of the hybrid powertrain. Using the engine cylinder pressure curve as the input boundary, the hybrid powertrain dynamics model is calibrated by transient dynamics analysis to obtain the hybrid powertrain transient dynamics model.

5. The starting noise control method of a hybrid vehicle according to claim 4, characterized by, The steps for performing transient dynamic analysis and calibration on the hybrid powertrain dynamic model, using the engine cylinder pressure curve as the input boundary, to obtain the transient dynamic model of the hybrid powertrain, specifically include: Using the engine cylinder pressure curve as the input boundary, transient dynamic analysis is performed on the hybrid powertrain dynamic model to calculate engine output torque fluctuation, powertrain mount active end vibration, powertrain surface structure vibration, gear and spline impact force, and calibrate and compare it with the actual test data to determine whether the calibration comparison structure is consistent. If so, then the transient dynamics model of the hybrid powertrain is obtained; If not, adjust the parameter information until the calibration comparison results are consistent.

6. The method for controlling the starting noise of a hybrid electric vehicle according to claim 1, characterized in that, The steps of gradually adjusting the initial phase angle of the crankshaft, and calculating the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface based on the hybrid engine thermodynamic simulation model and the hybrid powertrain transient dynamic model, specifically include: Starting from an initial phase angle of 0° on the crankshaft, and using a preset progressive angle, the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface are calculated based on the hybrid engine thermodynamic simulation model and the hybrid powertrain transient dynamic model. The preset progressive angle is 8° to 12°.

7. The method for controlling the starting noise of a hybrid electric vehicle according to claim 5, characterized in that, Based on the engine output torque fluctuations and the vibration amplitude of the transmission mating surface, the optimal initial phase angle is determined. When the hybrid engine shuts off, the crankshaft is calibrated to stop at the optimal initial phase angle to reduce starting noise. This process includes the following steps: The optimal initial phase angle is determined based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface. When the hybrid engine is turned off, the engine management system obtains the real-time position of the crankshaft through the crankshaft position sensor and sends it to the hybrid vehicle controller. The hybrid vehicle controller obtains the target position of the crankshaft based on the optimal initial phase angle and the real-time position of the crankshaft, adjusts the motor torque, and performs closed-loop control of the crankshaft angle. When the target position is approached, the torque is adjusted to zero to control the crankshaft stop position and reduce noise during the next start-up.

8. The method for controlling the starting noise of a hybrid electric vehicle according to claim 7, characterized in that, The method further includes: Starting from an initial crankshaft phase angle of 0°, and using progressive angles of 8° to 12°, we tested real engine output torque fluctuations, real transmission engagement surface vibration amplitudes, and near-field noise on a hybrid vehicle. The optimal region for the initial phase angle is obtained based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface. Based on the actual engine output torque fluctuation, the actual vibration amplitude of the gearbox mating surface, and the near-field noise, the optimal region is fine-tuned to obtain the optimal initial phase angle and determine the parameters used for calibration control.

9. A start-up noise control system for a hybrid electric vehicle, characterized in that, The system is used to implement the start-up noise control method for a hybrid electric vehicle according to any one of claims 1 to 8, the system comprising: The thermodynamic model construction module is used to collect relevant structural parameters of the hybrid engine, establish a thermodynamic simulation model of the hybrid engine, test various performance characteristics of the hybrid engine under preset operating conditions, and calibrate the thermodynamic simulation model of the hybrid engine. The thermodynamic model calibration module is used to calculate the engine cylinder pressure curve and torque fluctuation data of the hybrid engine during the start-up process by adjusting different initial phase angles of the crankshaft as input boundaries based on the thermodynamic simulation model of the hybrid engine. The dynamic model construction module is used to collect parameter information of the hybrid engine, dual-mass flywheel and multi-in-one transmission, construct the hybrid powertrain dynamic model, and perform transient dynamic analysis and calibration on the hybrid powertrain dynamic model with the engine cylinder pressure curve as the input boundary to obtain the hybrid powertrain transient dynamic model. The vibration calculation module is used to gradually adjust the initial phase angle of the crankshaft, and calculate the engine output torque fluctuation and the vibration amplitude of the gearbox mating surface based on the thermodynamic simulation model of the hybrid engine and the transient dynamic model of the hybrid powertrain. The phase adjustment module is used to determine the optimal initial phase angle based on the fluctuation of engine output torque and the vibration amplitude of the gearbox mating surface. When the hybrid engine is turned off, it calibrates and controls the crankshaft to stop at the optimal initial phase angle, reducing starting noise.

10. A hybrid electric vehicle, characterized in that, The hybrid electric vehicle includes the start-up noise control system of the hybrid electric vehicle as described in claim 9.

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