CN110296847B - Noise testing method for new energy passenger car - Google Patents

Abstract

The invention discloses a noise testing method of a new energy bus, which comprises the following steps: step 1, calling a sound pressure level curve in noise data from test data to serve as a sound sample, dividing the sound sample into m equal parts, and taking each equal part as an independent area; step 2, recording and replaying sound samples in a certain area through software, preferably selecting n sound pressure level curves with good feeling by 5-10 persons of a test engineer group and 5-10 persons of a user group, wherein n is more than or equal to 2, and drawing an outer envelope line based on the preferable samples; step 3, connecting the outer envelope lines in the m area in sequence to form an overall envelope line, namely a reference standard; and 4, when the sound quality of a certain vehicle is preliminarily evaluated, directly comparing the sound pressure level curve of the test sample with a reference standard.

Description

Noise testing method for new energy passenger car

Technical Field

The invention relates to a noise test method of a new energy bus, and belongs to the technical field of NVH test of pure electric buses.

Background

The evaluation method of sound quality can be divided into subjective evaluation and objective evaluation. The subjective evaluation of sound quality is an evaluation method from data acquisition, listening tests to data analysis, which is designed to know the characteristics of certain sounds and the feelings of people to the sounds. The subjective evaluation can deepen the understanding of the sound signals and obtain more comprehensive evaluation on the sound signals; the objective evaluation technology of the sound quality depends on the subjective evaluation technology, the existing sound quality objective quantity cannot completely describe the sound quality, and the new sound quality objective quantity is provided based on a large number of subjective evaluation experiments; the accuracy of the objective evaluation result of the sound quality needs to be verified through subjective evaluation experiments.

In the sound quality evaluation of the new energy passenger car, the vehicle with the sound pressure level lower than 78db (a) measured in the car is generally considered to be the vehicle with qualified sound quality, but in the actual production, the sound pressure level of the vehicle to be measured is 76db (a), and unacceptable buzzes still appear, so the evaluation method is very comprehensive. The sound quality is related to indexes such as loudness, sharpness and fluctuation, but the calculation formulas are complex, the calculation conditions are ideal, the influence factors are more, and the method cannot adapt to the actual production of fast paces.

Disclosure of Invention

The invention provides a noise testing method of a new energy bus in order to solve the problems in the prior art.

The technical scheme adopted by the invention is as follows: a noise test method of a new energy bus comprises the following steps:

step 1, calling a sound pressure level curve in noise data from test data to serve as a sound sample, dividing the sound sample into m equal parts, and taking each equal part as an independent area;

step 2, recording and replaying sound samples in a certain area through software, preferably selecting n sound pressure level curves with good feeling by 5-10 persons of a test engineer group and 5-10 persons of a user group, wherein n is more than or equal to 2, and drawing an outer envelope line based on the preferable samples;

step 3, connecting the outer envelope lines in the m area in sequence to form an overall envelope line, namely a reference standard;

and 4, when the sound quality of a certain vehicle is preliminarily evaluated, directly comparing the sound pressure level curve of the test sample with a reference standard.

The invention has the following beneficial effects:

(1) selecting a plurality of samples with higher sound quality from the plurality of groups of sound samples, and drawing an envelope line with proper standard as a reference standard of the sound samples;

(2) comparing the sound sample with noise problem with reference, the value of noise or abnormal sound higher than the range can be displayed visually;

(3) comparing the line type of the reference curve, the sound quality level of the collected sound sample can be visually judged;

(4) the envelope curve in the invention is compared with the sound sample to be evaluated, the sound quality of the sound sample can be preliminarily evaluated through linear comparison, and the specific numerical value of the sound sample exceeding the reference range can be intuitively obtained through comparison of sound pressure levels at various rotating speeds.

Drawings

FIG. 1 is a specific working process diagram of the noise testing method of the new energy bus.

Fig. 2 is a sound sample segmentation.

Fig. 3 is a plot of the segment first envelope.

Fig. 4 is a plot of the second segment envelope.

Fig. 5 is a plot of the overall envelope of the acceleration overall process.

Detailed Description

The invention will be further described with reference to the accompanying drawings.

Testing the working condition: on a straight road, when only an air conditioner is started in a vehicle, the vehicle to be tested is accelerated from a static state to a speed limit, and the rotating speed of a motor corresponding to the speed limit is 3000 rpm. The invention discloses a noise testing method of a new energy bus, which comprises the following steps:

step 1, calling a sound pressure level curve in noise data from test data to serve as a sound sample, dividing the sound sample into m equal parts, and taking each equal part as an independent area;

step 2, carrying out recording playback on the sound samples in a certain area through software, preferably selecting n (n is more than or equal to 2) sound pressure level curves which are good in feeling by a test engineer group (5-10 persons) and a user group (5-10 persons) together, and drawing an outer envelope (segmented envelope) based on the preferred samples;

and 3, sequentially connecting the envelope lines in the m area to form an overall envelope line, namely a reference standard.

And 4, when the sound quality of a certain vehicle is preliminarily evaluated, directly comparing the sound pressure level curve of the test sample with a reference standard.

By the same method, the envelope curves under the two working conditions of only opening the air pump, opening the air pump and opening the air conditioner at the same time can be obtained and are used as reference samples for evaluation under the corresponding working conditions.

The foregoing is only a preferred embodiment of this invention and it should be noted that modifications can be made by those skilled in the art without departing from the principle of the invention and these modifications should also be considered as the protection scope of the invention.

Claims (1)

1. A noise test method of a new energy bus is characterized by comprising the following steps: the method comprises the following steps:

step 1, calling a sound pressure level curve in noise data from test data to serve as a sound sample, dividing the sound sample into m equal parts, and taking each equal part as an independent area;

step 2, recording and replaying sound samples in a certain area through software, preferably selecting n sound pressure level curves with good feeling by 5-10 persons of a test engineer group and 5-10 persons of a user group, wherein n is more than or equal to 2, and drawing an outer envelope line based on the preferable samples;

step 3, connecting the outer envelope lines in the m area in sequence to form an overall envelope line, namely a reference standard;

and 4, when the sound quality of a certain vehicle is preliminarily evaluated, directly comparing the sound pressure level curve of the test sample with a reference standard.

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