What is car ride comfort? What are the requirements for test data?

The safe driving of a car is determined by many factors. In addition to the driver, the overall performance of the car also participates in driving safety, including stability, handling, and ride comfort. Generally, the stability and handling of the car are tested during the overall test. It is the performance that people pay more attention to, but ride comfort is often overlooked. So what is car ride comfort? The following editor of Naiou will give you a detailed introduction to the car ride comfort and the data requirements of the car ride comfort test for your reference.

 One、 what is car ride comfort

1. Overview of car ride comfort

The ride comfort of a car means that the vibration environment in which the occupants of the car is running has a certain degree of comfort and the performance of keeping the goods intact. The vibration of the car to the human body is transmitted to the human body through the three parts of the steering wheel, the seat and the floor. The vibration of the car steering wheel is transmitted to the human hand and arm system through the steering wheel. This vibration belongs to the category of local vibration, and the seat and the floor will vibrate. It is transmitted to the whole body and belongs to the category of whole body vibration. Since the ride comfort is mainly evaluated according to the comfort level of the occupants, it is also called ride comfort.

2. The role of car ride comfort

During the driving of the car, due to factors such as uneven road surface and changes in vehicle speed, the car vibrates, and the occupants are in such a vibration environment, and the vibration affects the comfort, work efficiency and physical health of the occupants. Maintain the comfort of the vibration environment to ensure that the driver has a good psychological state and accurate and sensitive response under complex driving and handling conditions. It affects the handling stability of the human-vehicle system and plays a very important role in ensuring driving safety. .

Two、 Data requirements for car ride comfort test

1, Class M vehicles: Collect the three positions of the driver and the top of the rear seat cushion on the same side, the seat back and the step floor, and measure the vibration in three directions at each position. For N-type vehicles, in addition to measuring the above three positions of the driver, it is also necessary to collect the vertical vibration of the vehicle floor center and the side of the driver 300mm from the side panel and the rear panel of the vehicle.

2. The center frequency of 1/3 octave for evaluating car ride comfort is 0.5~80Hz. Since the center frequency is 80Hz, the upper limit frequency is 90Hz. Therefore, the bandwidth of the collected time domain signal is not less than 90Hz.

3. When self-power spectral density is used to calculate the random input driving evaluation index, the national standard requires that the frequency resolution is not higher than 0.2Hz. However, since the lower and upper limit frequencies of the 0.5 Hz center frequency of the 1/3 octave band are 0.45 Hz and 0.57 Hz, in order to ensure that there is at least one spectral line in this frequency band, the frequency resolution cannot be higher than 0.19 Hz.

4. For random input driving independent samples q≥25, the number of independent samples is the number of data frames. Therefore, the length of the time domain signal to be collected should be greater than 25 frames (the data length of one frame is the reciprocal of the frequency resolution).

5. For random input driving, use Hanning window when calculating self-power spectral density.

6. The number of effective tests for each vehicle speed shall be no less than 5 times.

Three、 Factors affecting car ride comfort

1. Suspension stiffness: Suspension stiffness determines the natural frequency of the suspension system and has a greater impact on car ride comfort.

2. Selection of "Human-Seat" system parameters: In order to improve the ride comfort of the car and make the vibration transmitted to the human body smaller, when selecting the "Human-Seat" system parameters, first ensure that the human body is sensitive to the frequency range in the vertical direction 4~ 12Hz is in the damping zone.

3. Tires: Due to their elastic properties, tires absorb vibrations caused by uneven roads to a large extent, so it and the suspension ensure the smoothness of the car. The unbalance of the rotating mass of the wheels will cause the car to vibrate and affect the ride comfort and driving stability of the car, which is especially obvious at high speeds.

4. Non-suspended mass: The vibration of the non-suspended mass has a significant influence on the vibration acceleration of the suspended mass. Reducing the non-suspended mass can reduce the impact force transmitted to the suspended mass.

Regarding what is car ride comfort, the above is all the content compiled by Naiou editor for everyone. I hope it can be helpful to everyone. Luoyang Naiou Electric Co., Ltd. is a high-tech enterprise focusing on the R&D and production of automobile performance test system equipment. In order to improve the accuracy of automobile ride comfort test, it has developed and produced a set of automobile ride comfort test and analysis system, which is not only suitable for Formal ride comfort test is also suitable for vehicle suspension natural frequency damping test, etc. If necessary, you can leave a message on our website or call customer service for detailed consultation.