In the past, automotive durability meant ruggedness and longevity, but in recent years, it has expanded to include emotional tolerance to satisfy the user’s five senses, including noise, vibration, and ride comfort. NVH measures noise, vibration, and discomfort, and with the evolution of the road environment, quietness and ride comfort have become important factors in car purchases. Manufacturers are using NVH improvements to increase customer satisfaction and technology levels.
In the past, a car’s durability meant that it was durable and could be operated for a long time without breaking down, but in recent years, it has expanded to include the meaning of emotional durability, which includes not only the original meaning of durability but also satisfying the five senses of the user, including noise, vibration, and ride comfort. Among them, NVH is an item that evaluates the performance of a car, where N stands for noise, V for vibration, and H for harshness.
As the road environment in Korea and abroad has improved due to the development of materials and technologies for road paving, car drivers and passengers have become more sensitive to NVH characteristics. As a result, customers’ desire for quietness and ride comfort has increased, and NVH has become a decisive factor in purchasing a car. In addition, noise and vibration generated by the parts that make up the car body are items that cause customer complaints and increase the fatigue of the car itself. Therefore, since noise and vibration are related to the deterioration of all parts, the degree of NVH improvement is used to evaluate the technical level of the automobile manufacturer. Therefore, the automobile industry strives to improve NVH for quietness and ride comfort from the beginning of development to customer evaluation after sales.
NVH performance is more than just a technical aspect; it directly reflects the emotional satisfaction of customers. Emotional durability has become increasingly important as customers have come to view their cars not just as a means of transportation, but as a living space. A quiet interior and a smooth ride reduce fatigue on long drives and provide a pleasant environment for short trips within the city.
First, think about a time when you drove on a highway as opposed to a local or city road. You may have turned up the volume because you couldn’t hear the music or radio, or you may have felt stressed by the constant sharp sounds. Noise, which is measured in decibels (db), is divided into two types: the noise outside the car body and the noise inside the car that the occupants feel. Traditionally, efforts have been made to ensure that no noise is generated inside or outside, i.e., silent driving. Recently, however, there has been a shift from simply reducing sound pressure to creating sounds with artificial frequencies and waveforms that give people comfort and pleasure through an emotional approach.
In addition to the basic shudder from the engine running, the periodic shaking that occurs during the driving process, from starting the car to turning it on and off, is known as vibration. However, constant unpleasant vibrations can cause anxiety or motion sickness in occupants, so manufacturers strive to minimize these vibrations to provide a comfortable ride through the relaxed movement of the body. By analyzing the road surface that the body touches and the vibration caused by air resistance during acceleration, we find the optimized body structure and stiffness, and for the powertrain, which includes the engine, we proactively reduce basic vibration through mounting techniques.
In addition to driving on normal roads, unpleasantness or roughness felt by passengers when driving over seams or unevenness in the road is something that not only experts but also ordinary people can easily experience. Since discomfort and harshness cannot be expressed in objective numbers, they are caused by a combination of wheel alignment and pressure of tires, suspension steering, and shock absorber characteristics, and are verified by vehicle evaluation experts within the manufacturer while driving the actual vehicle.
To reduce stress and improve enjoyment for customers in the future, it will take more than just the concept of a car that doesn’t break down. Instead, we need a concept of a car that creates a more comfortable and psychologically reassuring environment for its occupants, and NVH represents this concept. The automotive industry is continuously researching and developing NVH technologies to improve customer satisfaction and enhance competitiveness. These changes are more than just technological advancements; they are leading to an overall change in automotive culture.
