노면변화에 따른 자동차 노면소음에 대한 연구

이태근,김병삼 한국기계기술학회 2021 한국기계기술학회지 Vol.23 No.5

Road surfaces and tires have a great influence on road noise in automobiles. Therefore, this study attempted to investigate the effect of changes in road surface and tire tread on road noise. For six road surfaces, road noise was measured and analyzed while changing two types of tire treads. In all frequency bands, the sound pressure of the road surface with a relatively large roughness was higher than that of other roads. And in the case of a road surface with relatively large pore, it was investigated that noise was reduced compared to other road surfaces due to the sound absorption effect in the low frequency area. On roads with irregular road roughness, the high sound pressure was exhibited in all frequency bands regardless of tire tread, indicating an increase in road noise due to irregular wear on roads. It was confirmed that the noise deviation due to the change in road surface was larger than the noise deviation due to the tire structure, and it is judged that noise research according to the structure and condition of the road surface.

Vibration Analysis of Moving Agricultural Machines using Road Surface Criteria

( Yuya Aoyagi ),( Masami Matsui ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Mitigating the negative impact of road surface roughness on the vibration of moving agricultural machines is important to ensure safe and comfortable farming. Herein, we developed a dynamical simulator for a tractor and rice transplanter. Using this simulator, the sensation of acceleration of the human body, when travelling on the road surface generated based on the ISO8608 road surface evaluation criteria, was calculated. The influence of the road surface frequency and surface roughness on the operator was considered by changing the maximum road surface frequency in the range of 3-10 c/m. Consequently, when evaluating the road surface roughness, it is suggested to consider frequencies of up to approximately 10 c/m owing to the influence of the frequency on the operator and the contact length of the wheels and road. Furthermore, the implementation of an appropriate anti-vibration mechanism is important because it is necessary to use the machines for a longer time during the agricultural season.

Generalized Linear Models to Identify the Impact of Road Geometric Design Features on Crash Frequency in Rural Roads

Moataz Bellah Ben Khedher,윤덕근 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

One of the first steps in improving the road network is to implement a traffic safety program and identify problematic road segments where local risk factors increase the likelihood of vehicular accidents. Numerous studies have attempted to identify both the geometric and traffic features of road segments that may lead to increased risk. The statistical models linking the number of accidents at road sites over a unit of time and the characteristics of these sites contribute to highlighting and quantifying the impact of the development of road infrastructure on the risk of accidents. The evaluation and selection of the best-fit model are usually carried out using an information criterion. The main purpose of this research is to propose a comparative assessment framework to support the evaluation task during the process of modeling crash frequency. Performance evaluation was conducted using additional approaches, specifically data splitting and rootograms. In this study, we focus on Korean rural road accident records. Six generalized linear models were applied, and their performance was compared to determine the best-fitting statistical model. According to each model assessment method used, the negative binomial hurdle model showed the best performance among all the investigated models.

Road-Frequency Adaptive Control for Semi-Active Suspension Systems

홍금식,Le Hoa Nguyen,박성훈 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.5

In this paper, a road-frequency adaptive control for semi-active suspension systems is investigated. The control aims to improve the vehicle suspension performance (ride comfort and wheel handling) for all frequency regions of road disturbances. In order to achieve this aim, the control law is extended from the conventional skyhook control, and the controller gains are scheduled for various frequency regions of road disturbances. By using the data measured from a relative displacement sensor, a state estimator based on a Kalman filter for estimating the required state variables is designed. Road disturbance frequencies are estimated by using a first order zero-crossing algorithm. The efficiency of the proposed control is shown through numerical simulations.

노면 변화에 기인한 자동차 도로소음에 관한 실험적 연구

김병삼(Byoung-Sam Kim) 한국자동차공학회 2013 한국자동차공학회 지부 학술대회 논문집 Vol.2013 No.5-1

Noise of the automobiles the part which relates the tendency which prefers the gradually quite vehicle with advancement and consumer demand level augmentation of technique is coming to be high, in order controls the tire noise which is considered seriously among the rest effectively from the evaluation which is objective and relationship between of the evaluation which is management appropriately, must define. Specially sound quality of the automobile inside simply sound arresting the inside in compliance with a size knows that is decided, in compliance with the quality of the frequency band which forms the sound market about the evaluation which is appropriate is demanded in order to undergo an influence. From the research which sees for the reduction which automobile tire noise is effective measures the plan condition and vehicle speed and the road surface of the tire affect in automobile road noise with the method which is objective and is measured. The following to this study, based on theoretical and experimental analyses, and the possibility of a low-noise tire development is presented and we have known that which road has noise characters from frequency.

Road-Frequency Adaptive Control for Semi-Active Suspension Systems

Nguyen, Le Hoa,Hong, Keum-Shik,Park, Seong-Hun 제어로봇시스템학회 2010 Transaction on control, automation and systems eng Vol. No.

In this paper, a road-frequency adaptive control for semi-active suspension systems is investigated. The control aims to improve the vehicle suspension performance (ride comfort and wheel handling) for all frequency regions of road disturbances. In order to achieve this aim, the control law is extended from the conventional skyhook control, and the controller gains are scheduled for various frequency regions of road disturbances. By using the data measured from a relative displacement sensor, a state estimator based on a Kalman filter for estimating the required state variables is designed. Road disturbance frequencies are estimated by using a first order zero-crossing algorithm. The efficiency of the proposed control is shown through numerical simulations.

ROAD NOISE REDUCTION OF A SPORT UTILITY VEHICLE VIA PANEL SHAPE AND DAMPER OPTIMIZATION ON THE FLOOR USING GENETIC ALGORITHM

유지우,Francesca Ronzio,Theophane Courtois 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.5

Road noise is always a major concern in automotive industries. The contribution of the floor of a automotive vehicle to road noise is large because of its large area and close location to chassis in terms of structure-borne noise. Therefore, the panel shape and damper of the floor should be carefully designed, which are effective on medium frequency region of the road noise. Because there are so many design options on the floor panels that experience high modal density and short wavelength at medium frequencies, traditional mode-decoupling approaches are no longer efficient. This study shows that a proposed optimization process based on a finite element model and a genetic algorithm is successful to reduce road noise at medium frequencies. Some background theories about the genetic algorithm and acoustic radiation efficiency in the frame of vibro-acoustics are explained to understand the optimization process. Vehicle performance evaluation and experimental study are given to validate this study. Finally, this verified process is applied to a sport utility vehicle (SUV) under development, whose road noise reduction is shown to be successful.

차량통행으로 발생하는 도로진동의 전파특성

박준철,유승도,신동석,이정희,설증민 한국소음진동공학회 1999 소음 진동 Vol.9 No.1

Ground vibrations induced from road were investigated to get the basic data that can be used to prepare countermeasures for environmental vibration problems. Vibration levels were measured simultaneously at three points in double distances from road. These data were analyzed with the type of vehicles. roads, media to understand the magnitudes and characteristics of distance attenuation of road vibrations. Vibration levels recorded on tapes were analyzed to understand the characteristics of frequency of road vibration. The range which could be influenced by the road vibration was estimated to take into account the mean of$L_{max}$ and distance attenuation of vibration level 5 m from roadside.

도로 기하구조에 따른 차량 Microphone 위치별 소음 영향 분석

문학룡,한대철,강원평 한국도로학회 2013 한국도로학회논문집 Vol.15 No.4

PURPOSES: The purpose of study is to understand the characteristic of driving noise from the front and rear tire for effective active noise cancellation application. METHODS : As literature review, noise measurement methods were reviewed. Noise measurement conducted at three kind of section by road slope using CPX(Close Proximity Method). Noise data was compared by total sound pressure level and 1/3 octave band frequency sound pressure level. Also, each section was compared by T-test using SPSS. RESULTS : In the case of the uphill section, it was shown that the sound pressure level of the front tire at Sugwang-Ri and Sinchon-RI sections was higher than that of the rear tire in low and high frequency band. In the case of high slope section of Sangsaek-Ri, the sound pressure level of the front tire was higher than that of the rear tire in high frequency. Also, in the case of the downhill section, it was shown that the sound pressure level of the front tire at Sugwang-Ri and Sinchon-RI sections was higher than that of the rear tire in low frequency band. However, the sound pressure levels of both the front and rear tires were approximately the same in the high slope section of Sangsaek-Ri. The result of T-test showed that total sound pressures of the front and rear tires were not different from each other in the case of high slope and high speed. CONCLUSIONS: Road slope was not an important variable for effective active noise cancellation.

1/4차량의 가상노면형상의 재구성

김연태(Yon-Tae Kim),김민석(Min-Seok Kim),이정한(Jeong-Han Lee),유완석(Wan-Seok Yoo) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.6

For the evaluation of ride quality and durability analysis of vehicle components by computer simulation, it is indispensable to consider nonlinear characteristics of tire and road. Most linear tire models are restrictive to represent this effect in the simulation. This paper proposes how to regenerate the road profile which preserves the measured wheel accelerations at the wheel center with linear tire model. The new road profile compensates for the difference of wheel acceleration between experiment and simulation using the frequency response function. The validity of the method was verified by appling to a 1/4 car model.