Automobile motor NVH test
1. Introduction
The main contents of this article: Overview of automotive NVH , automotive motor sound quality, and automotive motor order analysis. Automobile motor NVH test.
2. NVH Overview
NVH is the abbreviation of Noise , Vibration and Harshness . It is a comprehensive issue to measure the quality of automobile manufacturing. It gives the most direct feeling to the car, that is, the comfort and quietness of the ride.
In order to deal with the environmental, energy and sustainable development issues brought by traditional fuel vehicles, many countries and regions have introduced policies to encourage the development of new energy vehicles, which have led to the vigorous development of the new energy vehicle market. At the same time, the rise of new energy vehicles has driven the research and product development of battery technology, motor and electric drive system technology.
With the changes in structural systems and the iteration of technology, new energy vehicles focus on solving the noise and vibration of electric drive systems, that is, the noise and vibration of automotive motors and their controllers, during the NVH performance development process. MegaSig has a complete system from software testing algorithms to hardware testing equipment, which can efficiently and accurately test the noise and vibration of automotive motor products.
3. Sound quality test based on automotive motor products
Sound quality testing is very important for the design, manufacture and application of automotive motor products. It can ensure that the sound produced by automotive motor products is within a reasonable range, thereby ensuring the driving safety of consumers. Based on MegaSig ‘s BuildGo automated testing platform, scientific measuring instruments and acoustic analysis tools are used to identify and diagnose the sound quality of automotive motor products.
3.1、Automobile motor product sound quality test hardware configuration
3.2 . Automotive motor product sound quality test items
Sound quality Loudness test : Indicates the relative volume or intensity of the sound. Based on the collected signal, calculate the loudness of the motor when it is rotating.
Sound quality sharpness test: describes the strength of the high frequency part of the sound relative to the low frequency part. Based on the collected signal, calculate the clarity and sharpness of the motor when it rotates.
Sound quality roughness test: describes the irregular vibration or periodic change of the sound. Based on the collected signal, the roughness of the motor is calculated when it rotates.
Sound quality fluctuation test: describes the rapid change or fluctuation of the sound amplitude over time. Based on the collected signal, the dynamics and instability of the motor rotation are calculated.
3.3 . Automotive Motor Product Sound Quality Test Link
Here we take the automotive motor test link as an example:
The vehicle control module controls the rotation of the vehicle motor. The M 663+A 802 free-field microphone/ACC 1861 three-axis acceleration collects the complete signal of the engine rotation, and then transmits the collected signal back to the BuildGo automation platform through the PM 6181 data acquisition card for noise/abnormal sound/vibration analysis .
4. Order analysis test based on automotive motor products
Order Analysis is a method used to analyze vibration / sound signals of rotating machinery systems. This method correlates the vibration / sound signals with the rotational speed of the rotating machinery (usually expressed in revolutions per minute (RPM )), which can better identify the operating status and structural fault problems of the mechanical system.
4.1、Automotive motor product order analysis test hardware configuration
4.2 . Order Analysis Test of Automobile Motor Products
By analyzing the collected vibration / sound signals, these signals are decomposed into different order components, each order represents a multiple of the rotation frequency. The analyzed signals will be presented in a waterfall plot to visualize the timing and frequency distribution of the order components, helping R&D personnel to better understand the characteristics of the rotating mechanical system of automotive motor products, so as to take measures to improve the performance and reliability of the system.
From the data above, we can see that traditional order analysis is able to identify specific order anomalies caused by periodic faults (bearing, gear anomalies, etc.) in the rotating mechanical structure of automotive motors.
However, it is difficult to identify the out-of-band abnormal signals between orders caused by non-periodic faults in the rotating mechanical structure of the automobile motor (internal metal chips, foreign objects that fall into the motor, etc.).
In response to this situation, MegaSig has upgraded its algorithm based on traditional order analysis. It is an algorithm for identifying abnormal noise caused by non-structural faults during the speed change of rotating machinery. It is used to identify abnormalities caused by non-structural defects in rotating machinery products. This algorithm cuts and analyzes the three-dimensional color energy map, extracts the maximum value/mean value calculated in each grid and forms a two-dimensional numerical matrix, and then merges and arranges it into a one-dimensional data for limit judgment.
4.3、Automotive Motor Product Order Analysis Link
Here we take the automotive motor test link as an example:
After the automotive motor products are operating normally, the axial and radial M 663+A 802 free-field microphones collect sound signals, the axial and radial ACC 1861 three-axis accelerometers collect vibration signals, and the PM 6181 data acquisition card collects resolver signals, which are finally sent back to the BuildGo automation platform for order analysis.
In short, whether it is the sound quality test or order analysis of automotive motors, the ultimate goal is to help engineers and analysts identify automotive motor product failures in an effective way, optimize performance and improve mechanical systems to ensure that user experience, brand image and regulatory requirements are not affected.
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SOURCES / https://blog.csdn.net/MegaSig/article/details/132731674
