CN-121328242-B - New energy automobile power assembly vibration energy analysis and evaluation method and system

CN121328242BCN 121328242 BCN121328242 BCN 121328242BCN-121328242-B

Abstract

The invention provides a method and a system for analyzing and evaluating vibration energy of a power assembly of a new energy automobile, wherein the method comprises the steps of obtaining a power assembly digital model, and obtaining first material information of each part corresponding to an engine origin and second material information of each part in the power assembly digital model; the method comprises the steps of establishing a grid and a finite element model, reducing first material information and second material information based on the finite element model, inputting cylinder pressure excitation under steady-state working conditions to the finite element model to obtain an adaptive dynamics model, operating the adaptive dynamics model to obtain intermediate data, carrying out post-processing on acceleration data of the cylinder body surface and a suspension driving end of an engine to obtain post-processing time domain data, judging whether half-order vibration energy of the engine meets an acceptance limit value based on the time domain data, and optimizing the engine which does not meet the acceptance limit value. The invention provides a half-order vibration energy evaluation method and a standard, and provides an evaluation basis for forward simulation in the earlier stage.

Inventors

ZENG XIAOCHUN
XU XIAOXIANG
HUANG FENG
WEI TAO
LIAO SHANBIN
LOU DIMING
WANG YI
XIAO JIUCHANG
SHI XIUYONG
LIU DENGCHENG

Assignees

南昌智能新能源汽车研究院
江铃汽车股份有限公司

Dates

Publication Date: 20260512
Application Date: 20251217

Claims (6)

1. The method for analyzing and evaluating the vibration energy of the new energy automobile power assembly is characterized by comprising the following steps of: Acquiring a power assembly digital model of a new energy automobile, and acquiring first material information of each part in the power assembly digital model corresponding to an engine origin and second material information of each part in the power assembly digital model; establishing a grid and a finite element model based on the first material information and the second material information; reducing the finite element model, and inputting cylinder pressure excitation under a steady-state working condition to the finite element model to obtain an adaptive dynamics model; Solving the adaptive dynamics model to obtain acceleration data of the cylinder surface and the suspension driving end of the engine, and performing post-processing on the acceleration data to obtain post-processing time domain data; judging whether half-order vibration energy of the engine meets an acceptance limit value or not based on the post-processing time domain data; Optimizing the engine which does not meet the acceptance limit; the specific step of judging whether the half-order vibration energy of the engine meets the acceptance limit value based on the post-processing time domain data comprises the following steps: Calculating the total vibration energy root mean square value of all cylinders in the whole engine in a complete cycle period, and calculating the single vibration energy root mean square value of each cylinder in the whole engine in an ignition period; comparing the total vibration energy root mean square value with the single vibration energy root mean square value to obtain an acceptance limit value, and judging whether the half-order vibration energy of the whole engine is qualified or not; The specific steps of calculating the total vibration energy root mean square value of all cylinders in the whole engine in a complete cycle period and calculating the single vibration energy root mean square value of each cylinder in the whole engine in an ignition period comprise the following steps: The post-processing time domain data is subjected to band-pass filtering processing to obtain filtered time domain data, wherein the frequency of the band-pass filtering is 200 Hz-800 Hz; acquiring data of a crank angle of a calibration angle in the whole engine; Equally dividing the acquired data of the crank angles to obtain a plurality of crank angle components, wherein the number of the crank angle components is consistent with that of the cylinder bodies; Corresponding each crank angle component to an ignition period of each cylinder body, and calculating a root mean square value of time domain data of each cylinder body after filtering in the cylinder ignition period as a single vibration energy root mean square value; And calculating root mean square values of the filtered time domain data of all the cylinders in a complete cycle period as total vibration energy root mean square values, wherein the starting moment in the complete cycle period is a compression bottom dead center of a first cylinder, and the ending moment in the complete cycle period is a working bottom dead center of a last cylinder.
2. The method for analyzing and evaluating vibration energy of a power assembly of a new energy automobile according to claim 1, wherein each part in the power assembly digital model comprises an engine complete machine, a suspension, a hybrid gearbox, a dual-mass flywheel and an exhaust hot end.
3. The method for analyzing and evaluating vibration energy of a power assembly of a new energy automobile according to claim 2, wherein the first material information comprises mass center and inertia, and the second material information comprises stiffness damping of the suspension, inertia of the dual mass flywheel, spring ratio of the dual mass flywheel, frequency of a front-section damping belt pulley of the engine, and cylinder pressure curve data of the whole engine under typical steady-state working condition.
4. The method for analyzing and evaluating vibration energy of a power assembly of a new energy automobile according to claim 1, wherein the specific step of comparing the root mean square value of the total vibration energy with the root mean square value of the single vibration energy to obtain an acceptance limit value, and judging whether the half-order vibration energy of the whole engine is qualified comprises the following specific steps: creating a comparison formula, and substituting the total vibration energy root mean square value and the single vibration energy root mean square value into the comparison formula to obtain a size proportion value; processing and comparing the size proportion values in the database, and determining an acceptance limit value; and regarding the whole engine with the size proportion value larger than the acceptance limit value as disqualification of half-order vibration energy.
5. The method for analyzing and evaluating vibration energy of a power train of a new energy automobile according to claim 4, wherein the specific step of optimizing the engine that does not satisfy the acceptance limit value includes: and optimizing the modes of the internal and peripheral parts of the whole engine according to the actual condition of the hybrid power assembly of the new energy automobile so as to decouple the mode of a crank shaft system in the whole engine.
6. The utility model provides a new energy automobile power assembly vibration energy analysis evaluation system which characterized in that includes: The acquisition module is used for acquiring a power assembly digital model of the new energy automobile, and acquiring first material information of each part in the power assembly digital model corresponding to an engine origin and second material information of each part in the power assembly digital model; the establishing module is used for establishing a grid and a finite element model based on the first material information and the second material information; the excitation module is used for reducing the finite element model, inputting cylinder pressure excitation under a steady-state working condition to the finite element model, and obtaining an adaptive dynamics model; the processing module is used for solving the adaptive dynamics model to obtain acceleration data of the cylinder surface and the suspension driving end of the engine, and performing post-processing on the acceleration data to obtain post-processing time domain data; the judging module is used for judging whether half-order vibration energy of the engine meets an acceptance limit value or not based on the post-processing time domain data; the optimizing module is used for optimizing the engine which does not meet the acceptance limit value; the judging module is specifically configured to: Calculating the total vibration energy root mean square value of all cylinders in the whole engine in a complete cycle period, and calculating the single vibration energy root mean square value of each cylinder in the whole engine in an ignition period; comparing the total vibration energy root mean square value with the single vibration energy root mean square value to obtain an acceptance limit value, and judging whether the half-order vibration energy of the whole engine is qualified or not; The specific steps of calculating the total vibration energy root mean square value of all cylinders in the whole engine in a complete cycle period and calculating the single vibration energy root mean square value of each cylinder in the whole engine in an ignition period comprise the following steps: The post-processing time domain data is subjected to band-pass filtering processing to obtain filtered time domain data, wherein the frequency of the band-pass filtering is 200 Hz-800 Hz; acquiring data of a crank angle of a calibration angle in the whole engine; Equally dividing the acquired data of the crank angles to obtain a plurality of crank angle components, wherein the number of the crank angle components is consistent with that of the cylinder bodies; Corresponding each crank angle component to an ignition period of each cylinder body, and calculating a root mean square value of time domain data of each cylinder body after filtering in the cylinder ignition period as a single vibration energy root mean square value; And calculating root mean square values of the filtered time domain data of all the cylinders in a complete cycle period as total vibration energy root mean square values, wherein the starting moment in the complete cycle period is a compression bottom dead center of a first cylinder, and the ending moment in the complete cycle period is a working bottom dead center of a last cylinder.

Description

New energy automobile power assembly vibration energy analysis and evaluation method and system Technical Field The invention relates to the technical field of new energy automobile power assemblies, in particular to a new energy automobile power assembly vibration energy analysis and evaluation method and system. Background The special engine for mixing takes thermal efficiency as a core target, adopts a more efficient combustion system, and simultaneously needs to carry out light-weight design on hardware so as to reduce friction work of the engine, compared with a traditional engine, a crank shaft system of the special engine is thinner and lighter, and the problem of half-order knocking noise is brought, and the problem is obvious in parking charging working conditions, so that the sound quality in a vehicle is seriously influenced, and the special engine has become an industry problem. The problem of half-order knocking of the hybrid assembly is solved, regular clattering-dong sound appears subjectively, and the hybrid assembly can be obviously perceived under the parking power generation working condition. The production mechanism is that the engine crankshaft system generates bending deformation under the excitation of normal detonation pressure, and the air is radiated outwards through the outer surface of the mixing assembly. The current industry optimization scheme for the half-order problem of the hybrid assembly is mainly focused on the middle period of project development, after a power assembly or a test vehicle comes out, the problem is identified, and a correction scheme is proposed, wherein the related correction scheme comprises the steps of adjusting the flywheel parameters at the rear end, optimizing a crankshaft and the like, and the schemes have great influence on the development progress of the whole project at the middle period time node of the project. Currently, no technology for forward simulation and half-order vibration energy evaluation index exists in the industry. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a new energy automobile power assembly vibration energy analysis and evaluation method, which aims to solve the technical problems in the background art. In order to achieve the above object, the present invention is achieved by the following technical scheme: a new energy automobile power assembly vibration energy analysis and evaluation method comprises the following steps: Acquiring a power assembly digital model of a new energy automobile, and acquiring first material information of each part in the power assembly digital model corresponding to an engine origin and second material information of each part in the power assembly digital model; establishing a grid and a finite element model based on the first material information and the second material information; reducing the finite element model, and inputting cylinder pressure excitation under a steady-state working condition to the finite element model to obtain an adaptive dynamics model; Solving the adaptive dynamics model to obtain acceleration data of the cylinder surface and the suspension driving end of the engine, and performing post-processing on the acceleration data to obtain post-processing time domain data; judging whether half-order vibration energy of the engine meets an acceptance limit value or not based on the post-processing time domain data; engines that do not meet the acceptance limit are optimized. According to one aspect of the technical scheme, each part in the power assembly digital model comprises an engine complete machine, a suspension, a hybrid gearbox, a dual-mass flywheel and an exhaust hot end. According to an aspect of the above technical solution, the first material information includes a centroid and inertia, and the second material information includes stiffness damping of the suspension, inertia of the dual mass flywheel, a spring ratio of the dual mass flywheel, a frequency of a front-section damping pulley of the engine, and cylinder pressure curve data of the whole engine under typical steady-state working conditions. According to an aspect of the foregoing technical solution, the specific step of determining whether the half-order vibration energy of the engine satisfies the acceptance limit value based on the post-processing time domain data includes: Calculating the total vibration energy average root mean square value of all cylinders in the whole engine in a complete cycle, and calculating the single vibration energy average root mean square value of each cylinder in the whole engine in an ignition period; And comparing the total vibration energy average root mean square value of each cylinder body with the single vibration energy average root mean square value to obtain an acceptance limit value, and judging whether the half-order vibration energy of the whole engine is qualified or not. According to an aspect of the abov