Finite Element Modeling and Semiactive Control of Vibrations in Road Vehicles

Control of vibrations in lightweight road vehicle systems has placed increasingly higher demands on the technology required to accurately model and predict dynamic response of a vehicle system. In this paper, a method for modeling vehicles as systems of interconnected rigid and flexible bodies is presented. Finite element and component mode substitution techniques are employed to characterize elastic motions of flexible bodies in terms of minimal set of modal coordinates. Equations of motion and constraints of coupled system are written in terms of a set of reference and modal coordinates. Semiactive control techniques are then used for suppressing vibrations at some desired points, in the chassis, located away from suspension attachments. Remote measurement of local displacements and velocities at these points are used to implement a corrective control action into suspension dampers of adjustable damping characteristics. This method is applied to a planar vehicle model with flexible chassis traversing a bump. Numerical results demonstrate validity of the developed model and effectiveness of semiactive control in improving ride quality characteristics.