A New Approach to Improve Vehicle Ride Comfort and Brake Judder

• Main Authors: Yu-kuan Chang, 張羽寛
• Other Authors: Jiun-ren Hwang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/88244119315677713010

博士 === 國立中央大學 === 機械工程學系 === 101 === In the present thesis, two main issues were discussed: one is trying to provide a new approach to improve the vehicle ride comfort on the initial condition; the other is surveying the reasons of brake judder after a car has been driven for a long time. Based on electroencephalogram (EEG) data, the researcher developed a new scheme for vehicle ride comfort analysis. Experiments were carried out by conducting a test course with simultaneous recording of six subjects’ brainwaves. Subjects’ answers to a sensory questionnaire were also analyzed. The correlation between the brainwaves and sensory evaluation proved the feasibility of the application of EEG analysis to the ride comfort evaluation. Furthermore, the suspension parameters of the vehicle were modified based on the statistics obtained from the EEG analysis. Finally, by setting up a test model and designing an experiment on a real test course, the goal to improve the ride comfort was achieved. On the other hand, to dig up the reasons of brake judder, research data including customer satisfaction reports provided by J. D. Power and auto maintenance records from all maintenance service centers in Taiwan were collected. According to maintenance service centers, consumers’ complaints ratio about brake judder was the highest in the first 5000 km but it declined gradually with longer mileage to a constant ratio. After careful examination, it was found that variations in the thickness of brake discs caused by wear and rust were the main reason for brake judder. The researcher further not only established a numerical model to simulate the variation of disc thickness in the time domain but devised a formula to predict customers’ complaint ratio. Two crucial and controllable variations—storage days and consumer driving days were proposed to predict the complaint ratio. The accuracy of the prediction value was as high as 80%. Furthermore, the formula could be applied to all types of vehicles, which is meaningful and feasible in improving the quality and performance of vehicles.