Search Results

The tendency of high speed and low-weight of passenger car may result in the bad feeling of ride comfort and controllability so that new design concept and technology has been required to solve the problems. Especially, the tangential vibration of the steering wheel makes the driver uncomfortable seriously at high speed [1-5]. So to trace the origin, we use T.L.H. coordinate which is a standard in vehicle design, besides the steering wheel system and the frame are modeled by 20 D.O.F. to estimate dynamic characteristics of new cars with possible changes of the locations of linkages and material properties. Generally, the vehicle frame is considered as a rigid body in the vibration analysis of a vehicle. In this study, however, we have modeled the frame as a elastic body. Moreover, the effects of the dry friction in ball joint and tie-rod, king pin inclination and the side slip of the tire are included in the present analysis to supply design parameters required for new vehicles.

The vibration characteristics of steering wheel in front drive small-sized passenger cars are discussed. Vertical and lateral accelerations at the steering wheel are measured on typical road. Transfer functions between various sources and the steering wheel are identified from the experimental data using 2 channel FFT analyzer. The effect of engine vibration, road excitation and structural system characteristics are identified by experimental and analytical methods. A significant reduction in the vertical vibration is demonstrated in the data and has been achieved using several improvement in the structure and system.