Analysis Of The Ride Comfort Based On The Real Road Profiles

Road roughness is an important index in pavement performance evaluation, and it relates to three factors such as pavement, cars and persons, especially human body comfort. To reflect the level of road roughness more exactly, the dissertation takes the total weighted root mean square acceleration of human body as evaluation index. Human body mainly supports vertical, roll, and pitch three directions vibrations. This dissertation takes measured height of pavement as discrete values and establishes corresponding calculation method of human body total weighted root mean square acceleration based on ISO2631-1:1997(E) the evaluation criteria of vibration that human body can support.To simulate the actual vibration of cars exactly, this dissertation establishes a human-vehicle model of ten degrees of freedom, and calculates the acceleration, analyses the comfort for a road section of measured pavement height based on ISO2631-1:1997(E) and analyses the effective factors of human body comfort including vehicle speed, vehicle stiffness and damping. The conclusion is that the vertical acceleration has the greatest effects on human body through the comparison of vertical, roll, and pitch three directions weighted acceleration.Obtain pavement height temporal model through pavement displacement power spectrum and compare the solving in time domain and frequency domain in the same vibration parameter. The two results are nearly the same in vehicle speed of 80, 100 and 120km/h, which testifies the model is correct in this dissertation. The comparison of IRI and human body acceleration shows, in some cases, that human body acceleration can take into account the three factors of the road roughness, and evaluate road roughness much better.