Variable Stiffness and Variable Ride-height Suspension System and Application to Improved Vehicle Dynamics

In this paper, we have presented a novel design for a customizable automotive suspension system with independent control of stiffness, damping and ride-height; and demonstrated the concept through a suspension prototype. The major motivation for this design is to avoid the trade-offs, involved in suspension design, which arise from the conflicting requirements of comfort and handling. The objective of this paper is to explore the possible applications of variable stiffness and variable ride-height suspension system to achieve improved vehicle dynamics. The capability of achieving the desired performance depending on user preference, vehicle speed, road conditions and maneuvering inputs using the proposed system is demonstrated. The application of variable stiffness to achieve real-time alteration of pitch and bounce motion centers, and real time alteration of anti-pitch and anti-dive characteristics is discussed. Moreover the possibility of ensuring stability through real-time alteration of understeer-oversteer characteristics is explored. Numerous other applications of variable stiffness are possible as stiffness affects almost every aspect of ride and handling. Since the proposed system is the first system with independent control of ride-height and stiffness, the research area has been virtually unexplored. Hence it is also the objective of this paper to initiate further research in this area and to create a suitable strategy for controlling all the adaptive parameters to get improved performance.