Analysis On Drivers’ Response To Low Frequency Vibration Based On Cerebral Oxygenation

Drivers are always in vibration exposure in vehicle systems. Long time vibration can cause driving fatigue. Driving fatigue is a significant cause of traffic accidents. The research of the dynamic model of the human body and the mechanism of driving fatigue cause more and more concern. Dynamic response characteristics of human body can be measured by human body model. There are lumped parameter model, finite element model and the multibody model. Compared with the finite element model and the multibody model, the lumped parameter model is limited to one-directional analysis. It is simple to analyze and easy to validate with experiments. This paper established a seated human body model of seven degree of freedom based on lumped parameter model in vertical vibration. The characteristics of the human body were obtained by driving simulation and least square method. It provides a theoretical basis for the remission of vehicle vibration.Vehicle vibration can cause the decrease of the cerebral oxygen. The research of the driver’s cerebral oxygen is important to the study on the mechanism of driving fatigue. Near-infrared spectroscopy (NIRS) is capable of noninvasively detecting human tissue’s oxygenation, continuously and in real time. Compared with the short-time Fourier transform and Fourier transform, wavelet transforms can be refined for local signals analysis. Statistical analysis and wavelet analysis are used. NIRS is used to detect human tissue’s oxygenation. Wavelet analysis is used to analysis the relation of driving fatigue and vibration frequency.The main job is as follows:(1) This paper established a seven degree of freedom seated human body model based on lumped parameter model. The driving simulator is used to simulate the driving task. The displacement of the seat, back, and head organization is measured by POLARIS measurement system under different frequency in vertical vibration. To reduce errors, the experiment data is measured many times. The stiffness and damping coefficient of the model is gotten by least square method. The characteristics of human body provide a theoretical basis for the design of vibration control system.(2) Human body tissue’s oxygenation is measured by TASH-100.The decrease tendency of the human tissue’s oxygenation reveals that long time driving can lead to driving fatigue.(3) Wavelet analysis of the data of the human body tissue’s oxygenation under different frequencies is used to verify the accuracy of the human body model. It also provides a theoretical basis for the design of the vehicle vibration reduction system and for the prevention and relieve of the driving fatigue.(4) The remission of vehicle vibration and fatigue driving is proposed based on the vibration response characteristics of human body and the changing tendency of cerebral oxygen.