King of Industry

  Chapter 105 The term "NVH"

   What Zhao Guoyang said was not only conceited, but even arrogant.

  Don't talk about Mo Xiaotian, even Zhu Maotao felt a little unbelievable after hearing this.

  Mo Xiaotian smiled instead of anger: "Oh, Section Chief Zhao, you can teach me, I, Mo, will listen carefully."

  Zhao Guoyang gave a "hmm", pointed to the book and said unceremoniously: "First of all, I think it is very inappropriate for you to share this question with Researcher Zhao."

   "Brother, you should know that she is only a student in the first year of research. She doesn't know much about the performance of vehicles, and her thinking is very limited. It is really difficult for her to try to solve this kind of problem."

  After Zhao Guoyang finished speaking, Zhao Siyan looked at her teacher Zhu Maotao in surprise.

  In fact, when Mo Xiaotian shared this topic with Zhao Siyan, Zhu Maotao also said similar things.

  However, because of Zhao Siyan's proactive request, he finally reluctantly agreed.

  But Professor Zhu also said something beforehand, so Zhao Siyan was only allowed to try to conceive some ideas, and she was not allowed to get involved too deeply, because she was afraid that she would get into the corner and eventually get in and not be able to climb out.

Zhao Guoyang did not notice the strangeness between Zhao Siyan and Professor Zhu, and continued to speak: "Brother Mo, your subject, to put it bluntly, is an extension of 'NVH'. Put it between the Beijing Jeep and the Songjiang Santara." Among the specific examples of comparison..."

   "NVH?" Mo Xiaotian looked at Zhao Guoyang blankly, as if he had never heard of this term.

  Jiang Hong, Liu Renhe, and Liu Yaohong also look at me and you, all with confused faces.

  Only Wang Ziqing and Zhu Maotao looked at Zhao Guoyang with a gleam in their eyes.

   Especially Zhu Maotao looked at Zhao Guoyang without blinking as if he had discovered a new continent.

  Seeing the bewildered look on Mo Xiaotian's face, Zhao Guoyang was stunned for a moment, and then realized: The term "NVH" was only introduced from Western countries in the late 1980s, and it has not yet become popular in China.

  Mo Xiaotian didn't know, and it wasn't a strange thing.

   "The so-called NVH is the English abbreviation of the three terms noise, vibration, and harshness (Noise, Vibration, Harshness

   "This is a comprehensive issue to measure the quality of car manufacturing, and it gives car users the most direct and superficial feeling."

"According to the current development trend, the NVH problem of vehicles has become one of the concerns of major vehicle manufacturers and parts companies in the international automobile industry. In the future, with the continuous improvement of people's requirements for vehicle comfort, its importance It has to be taken to a higher level.”

  Zhao Guoyang looked calm and explained eloquently, as if he had returned to the time when he spoke at various seminars in the past.

"Researcher Mo must also know that to evaluate the performance of a car, there are usually various data indicators. For example, the power performance includes the maximum speed, acceleration time and maximum gradient; the economy includes fuel consumption per 100 kilometers, car maintenance costs, etc. .So how do you evaluate the comfort of a car?"

Seeing Mo Xiaotian's stunned look, Zhao Guoyang smiled and continued: "From the perspective of 'NVH', as long as the car can ensure that the impact of noise, vibration and shock environment on the occupants is within a certain limit during driving, So the comfort is mainly evaluated based on the subjective feelings of the occupants.”

   "However, here lies the problem. Due to the different psychological and physical qualities of each person, their sensitivity to 'NVH' is very different."

   "This thing, to put it bluntly, is like aesthetics. Different people have different opinions. Sometimes, the appearance of a car that you think is 'OK', in the eyes of another person, you just think it is not good."

"In addition to the differences in the sensitivity of each person, we also have to take into account the differences of each model. For example, a sports car must hear the roar of the engine before it can feel the control; while an off-road vehicle must feel its strong The sense of collision is favored by people."

   "So for the 'NVH' issue, there are different requirements for different models, which brings difficulties to the early design."

  When Zhao Guoyang spoke up to this point, everyone was already concentrating, without panting, for fear of missing such a wonderful commentary.

  Even Zhao Siyan, who had always been displeased with him, rested her cheeks on her hands and stared at him without blinking her big watery eyes.

  Zhao Guoyang opened the thermos, drank some water, moistened his throat and said, "Then, it's like this defense question. The question is to analyze the performance difference between the Beijing Jeep and the Songjiang Santana."

"You list this simulation optimization model, analyze and compare the climbing ability, speed and comfort of Jingcheng Jeep and Songjiang Santara. Is there anything wrong with this, yes! But it's not comprehensive, is it objective? It's hard to say gone."

   "To give a simple example, the Beijing Jeep is definitely not as comfortable as the Santara when it is driven on flat ground or on the highway, but if you drive it in the Gobi, on the beach, or in the mud, it must be better."

   "In this respect, the two are not comparable at all! Then what's the point of your simulation model?"

  Zhao Guoyang tapped the desktop lightly and said: "In fact, in the development process of a model, simulation optimization is essential. To some extent, it can greatly reduce the cycle of car development."

"Taking the strength optimization of ordinary structures as an example, if we know that the strength is insufficient somewhere in the simulation results, then we can immediately think of changing materials, adding reinforcement ribs, optimizing the structure and other methods to solve the problem. This method can be effective and accurate. The body structure has been improved, and the matching rate between the simulation and the actual measurement is quite high.”

  “But in terms of NVH, although it has a series of methods such as various simulations, vibration tests, and vehicle vibration tests, it is still unable to obtain accurate and objective conclusions.”

  “Most of the time, the simulation results are far from the measured data, and it is difficult to achieve the effect of reducing costs and production cycles.”

   "Therefore, in my opinion, your project has gone in the wrong direction from the very beginning!"

  Zhao Guoyang's last words were like a thunderclap on the ground, shocking everyone present.

  Zhu Maotao held back his excitement, and asked word by word: "Xiao Zhao, if you are here to defend, how are you going to do this subject?"

  Zhao Guoyang was so excited just now that he didn't pay attention to the expressions of the group of people around him. Hearing Professor Zhu's question at this time, he naturally couldn't neglect it, stood up quickly, and expressed his opinion.

   "Professor Zhu, if I were to solve this subject, I would not build a simulation and control system, but focus on the after-sales of Songjiang Santara and Jingcheng Jeep..."

   "First, I will select a few common problem feedbacks from the after-sales feedback of these two cars. Then, based on the solutions to these problem feedbacks, I will list a data comparison table."

   "This table has a vertical comparison and a horizontal comparison. The vertical comparison is the comparison of the feedback information of the same model from the user before and after the problem is solved; the horizontal comparison is the comparison of the handling of similar problems between the two models..."

  Zhao Guoyang finally concluded: "After the results of these two comparisons come out, the difficult problem you raised, Professor Zhu, is basically solved."

  (end of this chapter)