Parameter Identification And Test Method For Low Frequency And Multi-direction Vibration Of Automobile Human-Seat System

Small scale electric car with light weight, miniaturization, electric in a body, has the obvious advantage of energy saving and environmental protection. It is will become an important direction of development of the automotive industry. However, the small scale electric car has produced the new academic and technical problems in the handling stability.Based on the National Nature Science Fund-Research on Modeling Method and Behavior Coupling of Human-Machine Dynamics for Small Scale Electric Vehicle, this article has studied the mechanical properties of person-chair system which connects sitting posture person and vehicle, established 12 degrees of freedom person-chair dynamics model, and identified the kinetic parameters of the model.The main content of this paper is as follows:First, according to the lumped parameter modeling method, twelve DOF person-chair mathematical models has been made based on three DOF person-chair model and nine DOF person-chair model. This linear model is consisting of two mass, three connections : upper body、lower body and waist. It can rotate and translate in Longitudinal, vertical, horizontal.Second, the person-chair system low frequency multidirectional vibration test stand has been developed. It is through the assembly of different and driving crank connecting rod mechanism by electric machinery, realization to the6 direction of human body vibration. The frequency of test bed is 0.5~5 Hz and amplitude of 4 mm. we use the micro aviation posture sensor to detect the acceleration and angular velocity of human body and bottom plate and present them in LABVIEW.Third, finishing low frequency multidirectional vibration test of the person-chair system and analyzing the characteristics of the data, analysis of signal characteristics of each direction, choose the main movement and the secondary movement, and simplify the formula of the person-chair system mathematical model.Finally, Selecting genetic algorithm to identification experiment parameters, fitting curve of frequency response characteristic, through different fitting order determine the final 36 stiffness and damping parameters of person-chair system model under the condition of low frequency dynamics.At the same time,Selecting the participants with different quality, height and gender and analyzing and comparing the influence of the height and gender on the human body kinetic parameters.The person-chair system dynamic model and the parameters identified of the model in this paper is helpful to guide the design of micro-electric vehicle, It also is a aspect of human-machine dynamic coupling effects. The model built in this paper offers a new idea to the research of person-chair interaction, and has a certain reference value.